Comprehensive Textbook of Echocardiography Volume 2

Vol. Comprehensive Textbook of Echocardiography

Vol. Comprehensive Textbook of Echocardiography

Editor

Navin C Nanda MD

Distinguished Professor of Medicine and Cardiovascular Disease and Director, Heart Station/Echocardiography Laboratories University of Alabama at Birmingham and the University of Alabama Health Services Foundation The Kirklin Clinic, Birmingham, Alabama, USA President, International Society of Cardiovascular Ultrasound

Under the Aegis of The International Society of Cardiovascular Ultrasound and The Indian Academy of Echocardiography

®

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD New Delhi • London • Philadelphia • Panama

®

Jaypee Brothers Medical Publishers (P) Ltd Headquarters Jaypee Brothers Medical Publishers (P) Ltd 4838/24, Ansari Road, Daryaganj New Delhi 110 002, India Phone: +91-11-43574357 Fax: +91-11-43574314 Email: [email protected] Overseas Offices J.P. Medical Ltd 83, Victoria Street, London SW1H 0HW (UK) Phone: +44-2031708910 Fax: +02-03-0086180 Email: [email protected]

Jaypee-Highlights. Medical Publishers Inc City of Knowledge, Bld. 237 Clayton, Panama City, Panama Phone: +1 507-301-0496 Fax: +1 507-301-0499 Email: [email protected]

Jaypee Brothers Medical Publishers (P) Ltd 17/1-B Babar Road, Block-B Shaymali, Mohammadpur Dhaka-1207, Bangladesh Mobile: +08801912003485 Email: [email protected]

Jaypee Brothers Medical Publishers (P) Ltd Shorakhute, Kathmandu Nepal Phone: +00977-9841528578 Email: [email protected]

Jaypee Medical Inc. The Bourse 111 South Independence Mall East Suite 835, Philadelphia, PA 19106, USA Phone: +1 267-519-9789 Email: [email protected]

Website: www.jaypeebrothers.com Website: www.jaypeedigital.com © 2014, Jaypee Brothers Medical Publishers The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not necessarily represent those of editor(s) of the book. All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission in writing of the publishers. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative information about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contraindications. It is the responsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/ editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book. This book is sold on the understanding that the publisher is not engaged in providing professional medical services If such advice or services are required, the services of a competent medical professional should be sought. Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any have been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity. Inquiries for bulk sales may be solicited at: [email protected] Comprehensive Textbook of Echocardiography (Vol. 2) First Edition: 2014 ISBN 978-93-5090-634-7 Printed at:

Dedicated to My late parents Balwant Rai Nanda MD and Mrs Maya Vati Nanda My wife Kanta Nanda MD Our children Nitin Nanda, Anita Nanda Wasan MD and Anil Nanda MD Their spouses Sanjeev Wasan MD and Seema Tailor Nanda, and our grandchildren Vinay and Rajesh Wasan, and Nayna and Ria Nanda

Contributors Masood Ahmad M D FRCP (C) FACP FACC

FAHA FASE

Division of Cardiology Department of Internal Medicine University of Texas Medical Branch Galveston Texas, USA

Dheeraj Arora DNB PDCC MNAMS Institute of Critical Care and Anesthesia Medanta The Medicity Gurgaon, Haryana, India

Mohammad Al-Admawi MD King Faisal Specialist Hospital and Research Center Heart Center Riyadh, Saudi Arabia

Bader Almahdi MD

Manreet Basra MBBS

Monodeep Biswas MBBS MD

Professor of Medicine University at Buffalo School of Medicine and Biological Sciences New York, USA

Division of Cardiology Geisinger-Community Medical Center, and The Wright Center for Graduate Medical Education Scranton, Pennsylvania, USA

Charles E Beale MD Department of Medicine Division of Cardiovascular Diseases Stony Brook University Medical Center Stony Brook, New York, USA

Roy Beigel MD The Heart Institute, Cedars Sinai Medical Center, Los Angeles, California, USA The Leviev Heart Center Sheba Medical Center, Affiliated to the Sackler School of Medicine Tel Aviv University, Tel Aviv, Israel

Steven Bleich MD Department of Medicine Division of Internal Medicine University of Alabama at Birmingham Birmingham, Alabama, USA

O Julian Booker MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Eduardo Bossone MD PhD FCCP FESC FACC

Echocardiography and Vascular Lab Assistant Professor of Medicine New York University School of Medicine New York, New York, USA

Via Principe Amedeo Lauro (AV), Italy Heart Department, University of Salerno, “Scuola Medica Salernitana” Salerno, Italy Department of Cardiac Surgery IRCCS Policlinico San Donato, Milan, Italy

Division of Cardiology Department of Medicine University of Texas Medical Branch Galveston, Texas, USA

Kunal Bhagatwala MBBS

Luis Bowen MD

Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Department of Medicine University of Alabama at Birmingham Birmingham, Alabama, USA

Neeraj Awasthy FNB

Aditya Bharadwaj MD

Gerald Buckberg MD

Department of Cardiology Loma Linda University and VA Medical Centers Loma Linda, California, USA

Department of Cardiothoracic Surgery David Geffen School of Medicine University of California-Los Angeles Los Angeles, California, USA

Heart Center, St Christopher’s Hospital for Children and Section of Cardiology Department of Pediatrics, Drexel University College of Medicine Philadelphia, Pennsylvania, USA

Aarti H Bhat MBBS

Michael J Campbell MD

Assistant Professor Division of Pediatric Cardiology Seattle Children’s Hospital and University of Washington Seattle, Washington, USA

Department of Pediatrics Division of Pediatric Cardiology Duke University Medical Center Durham, North Carolina, USA

Piers Barker MD

Nicole Bhave MD

FRCP FACC


University Health Network Toronto General Hospital University of Toronto Toronto, Ontario, Canada

Professor Emeritus Division of Cardiology UC-Irvine School of Medicine Irvine, California, USA

King Faisal Specialist Hospital and Research Center Heart Center Riyadh, Saudi Arabia

Ahmed Almomani MBBS

Fortis Escorts Heart Institute New Delhi, India

Rula Balluz MD MPH

Ricardo Benenstein MD

Premindra PAN Chandraratna MD

viii

Comprehensive Textbook of Echocardiography

Leon H Charney

Michele D’ Alto MD PhD

Daniel Forsha MD

Division of Cardiology New York University Medical Center New York, New York, USA

Department of Cardiology Second University of Naples: Monaldi Hospital, Naples, Italy


Farooq A Chaudhry M D FACP FACC

David Daly MD

FASE FAHA

Professor of Medicine Director, Echocardiography Laboratories Associate Director, Mount Sinai Heart Network, Icahn School of Medicine at Mount Sinai, Zena and Michael A Wiener Cardiovascular Institute and Marie-Josée and Henry R Kravis Center for Cardiovascular Health New York, New York, USA

Preeti Chaurasia MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama

Reema Chugh MD FACC Consultant in Cardiology/Specialist in Adult Congenital Heart Disease and Heart Disease in Pregnancy Kaiser Permanente Medical Center Panorama City, California, USA

Krishnaswamy Chandrasekaran MD Mayo Clinic, Scottsdale, Arizona, USA Rochester, Minnesota, USA

Michael Chen MD University of Washington Seattle, Washington DC, USA

HK Chopra MD Moolchand City Hospital New Delhi, India

Department of Medicine University of Alabama at Birmingham Birmingham, Alabama, USA

Hisham Dokainish M D FRCPC Associate Professor of Medicine McMaster University Director of Echocardiography and Medical Diagnostic Units Hamilton Health Sciences Hamilton, Ontario, Canada

Maximiliano German Amado Escañuela MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Bahaa M Fadel MD King Faisal Specialist Hospital and Research Center Heart Center Riyadh, Saudi Arabia

Naveen Garg MBBS Dip. Cardiology Fellow, Noninvasive Cardiac Lab Indraprastha Apollo Hospitals New Delhi, India

Luna Gargani MD Institute of Clinical Physiology National Research Council Pisa, Italy

Eleonora Gashi DO MPhil

Robert P Gatewood Jr MD FACC

Division of Cardiology Fondazione Cardiocentro Ticino Lugano, Switzerland


Honorary Consultant Imperial and King's Colleges, London, UK

University of Illinois Hospital & Health Science System Jesse Brown VA Medical Center Chicago, Illinois, USA

Francesco Faletra MD

Francesco Ferrara MD

David Cosgrove MD

Leon J Frazin MD

Fellow, Division of Cardiology Allegheny General Hospital Pittsburgh, Pennsylvania, USA

Heart Department, University of Salerno “Scuola Medica Salernitana” Salerno, Italy Department of Internal Medicine and Cardiovascular Sciences University “Federico II” of Naples Naples, Italy

Director, Division of Clinical Cardiology Program Director, Cardiovascular Fellowship, Lenox Hill Hospital New York, USA

Department of Cardiology Loma Linda University and VA Medical Centers, Loma Linda California, USA

Senior Cardiology Fellow Lenox Hill Hospital Non-Invasive Cardiology New York, New York, USA

Abid Ali Fakhri MD

Cecil Coghlan MD

Neil L Coplan MD FACC

Gary P Foster MD

Brandon Fornwalt MD PhD Assistant Professor of Pediatrics Department of Pediatrics University of Kentucky Lexington, Kentucky, USA

Chief of Cardiac Services Kaleida Heath; Clinical Associate Professor of Medicine University at Buffalo School of Medicine and Biological Sciences Buffalo Cardiology and Pulmonary Associates, Main Street Williamsville New York, USA

Shuping Ge MD FAAP FACC FASE Chief, Section of Cardiology St Christopher’s Hospital for Children Associate Professor of Pediatrics Drexel University College of Medicine Philadelphia, Pennsylvania, USA Acting Chair, Pediatric Cardiology Deborah Heart and Lung Center Browns Mills, New Jersey, USA

Contributors

ix

Gopal Ghimire MD DM MRCP

Donald Hagler MD

Rachel Hughes-Doichev MD FASE

Division of Cardiovascular Diseases University of Alabama at Birmingham Birmingham, Alabama, USA

Mayo Clinic Rochester, Minnesota, USA

Temple University School of Medicine Pittsburgh, Pennsylvania, USA

Stephanie El-Hajj MD

Arzu Ilercil MD

Nina Ghosh MD

Department of Internal Medicine Louisiana State University Health Sciences Center Baton Rouge, Louisiana, USA

Associate Professor of Medicine Department of Cardiovascular Sciences University of South Florida Tampa, Florida, USA

Kamran Haleem MD

Trevor Jenkins MD

Division of Cardiovascular Medicine Brigham and Women’s Hospital Harvard Medical School Francis Street Boston, Massachusetts, USA

Edward Gill MD Professor of Medicine and Cardiology, University of Washington Seattle, Washington DC, USA

Rohit Gokhale MBBS University at Buffalo Buffalo, New York, USA

Aasha S Gopal MS MD FACC FAHA FASE Associate Professor of Medicine Stony Brook University Stony Brook, New York, USA Director, Advanced Echocardiography St Francis Hospital, Washington Blvd Roslyn, New York, USA

Willem Gorissen Clinical Market Manager Toshiba Medical Systems Europe Zoetermeer, The Netherlands

Luis Gruberg MD FACC Department of Medicine Division of Cardiovascular Diseases Stony Brook University Medical Center Stony Brook, New York, USA

Rakesh Gupta MD JROP Healthcare New Delhi, India

Fadi G Hage MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA Section of Cardiology, Birmingham Veteran’s, Administration Medical Center Birmingham, Alabama, USA

Yale University New Haven, Connecticut, USA

Dan G Halpern MD St Luke’s-Roosevelt Hospital Center Columbia University, College of Physicians and Surgeons New York, New York, USA

Rachel Harris MD MPH Morehouse School of Medicine Section of Cardiology Assistant Professor Echo Lab Co-Director Grady Memorial Hospital Atlanta, Georgia, USA

Christine Henri MD Department of Cardiology Heart Valve Disease Clinic CHU Sart Tilman, University of Liège, Belgium

Julien IE Hoffman MD Department of Pediatrics University of California San Francisco, California, USA

Brian D Hoit MD Director of Echocardiography Harrington Heart & Vascular Center University Hospitals of Cleveland Texas, USA

Steven J Horn MD FACC FASE FASNC SUNY Buffalo Buffalo, New York, USA

Ming Chon Hsiung MD Cardiologist Cheng Hsin General Hospital Taipei, Taiwan

Harrington Heart and Vascular Institute University Hospital Case Medical Center, Cleveland Ohio, USA

Madhavi Kadiyala MD Saint Francis Hospital, Roslyn New York, USA

Arshad Kamel MD Department of Medicine University of Alabama at Huntsville Huntsville, Alabama, USA

Abdallah Kamouh MD University of Buffalo Buffalo, New York, USA

Poonam Malhotra Kapoor MD All India Institute of Medical Sciences New Delhi, India

Kanwal K Kapur MD DM Cardiology, Sr Consultant and Chief Noninvasive Cardiology Indraprastha Apollo Hospitals New Delhi, India Department of Noninvasive Cardiology Indraprastha Apollo Hospitals New Delhi, India

Nidhi M Karia MBBS Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Jarosław D Kasprzak MD Chair and Department of Cardiology Biegański Hospital Medical University of Lodz Lodz, Poland

x


Martin G Keane MD FACC FAHA FASE

Arthur J Labovitz MD

Gerald R Marx MD

Professor of Medicine Cardiology Section Director of Echocardiography Temple University School of Medicine Parkinson Pavilion, Suite North Broad Street, Philadelphia Pennsylvania, USA

Professor of Medicine Chair, Department of Cardiovascular Sciences University of South Florida Tampa, Florida, USA

Associate Professor Harvard School of Medicine Senior Associate Cardiology Boston Children’s Hospital Boston, Massachusetts, USA

Jennifer K Lang MD

Wilson Mathias Jr MD

University at Buffalo Buffalo, New York, USA

Heart Institute (InCor) The University of São Paulo School of Medicine and Fleury Group São Paulo, Brazil

Tuğba Kemaloğlu Öz MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Anant Kharod MD Department of Medicine University of Alabama at Birmingham Birmingham, Alabama, USA

Jennifer Kiessling MD Division of Cardiovascular Diseases, University of Alabama at Birmingham Birmingham, Alabama, USA

Allan L Klein M D FRCP(C) FACC

Roberto M Lang MD University of Chicago Medical Center Chicago, Illinois, USA

Fabrice Larrazet MD PhD Department of Cardiology HÔpital Saint Camille Bry sur Marne, France

Steve W Leung MD Assistant Professor of Medicine Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky, USA

FAHA FASE

Angele A A Mattoso MD Heart Institute (InCor) The University of São Paulo School of Medicine, São Paulo, Brazil and Santa Izabel Hospital, Salvador, Bahia

Sula Mazimba MD MPH Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Anjlee M Mehta MD Fellow, Division of Cardiology Dartmouth-Hitchcock Heart and Vascular Center Lebanon, New Hampshire, USA

Director, CV Imaging Research and Pericardial Center Professor of Medicine, Cleveland Clinic Heart and Vascular Institute Department of Cardiovascular Medicine Cleveland, Ohio, USA

Sachin Logani MD

Smadar Kort MD FACC FASE

Javier López MD PhD


Professor of Medicine State University of New York Stony Brook Director Non Inavasive Cardiac Imaging Director Echocardiography Diretor Valve Center, Stony Brook Medicine Stony Brook, New York, USA

Hospital Clinico Universitario de Valladolid, Spain

Yatin Mehta MD MNAMS FRCA FAMS

Itzhak Kronzon M D FASE FACC FACP

Department of Medicine Division of Cardiovascular Diseases Stony Brook University Medical Center, Stony Brook New York, USA

FIACTA FTEE FICCM

Judy R Mangion MD Division of Cardiovascular Medicine Brigham and Women’s Hospital Harvard Medical School Francis Street, Boston Massachusetts, USA

FESC FAHA

Professor of Cardiology Hofstra University North Shore LIJ, School of Medicine Chief of Noninvasive Cardiac Imaging Lenox Hill Hospital Noninvasive Cardiology New York, New York, USA

Kruti Jayesh Mehta MBBS PGDCC

CN Manjunath MD DM Director, Professor and Head Department of Cardiology Sri Jayadeva Institute of Cardiovascular Sciences and Research Bannergutta Road Bengaluru, Karnataka, India

Institute of Critical Care and Anesthesia Medanta The Medicity Gurgaon, Haryana, India

Julien Magne PhD Department of Cardiology Heart Valve Disease Clinic CHU Sart Tilman, University of Liège, Belgium

Andrew P Miller MD Cardiovascular Associates Birmingham, Alabama, USA

Contributors

Dilbahar S Mohar MD

Ryozo Omoto MD

Eugenio Picano MD PhD

Division of Cardiology UC-Irvine School of Medicine Irvine, California, USA

Professor Emeritus, Saitama Medical University Honorary Director, Saitama Medical University Hospital Moro-Hongou, Moroyama Iruma-Gun, Saitama, Japan

Institute of Clinical Physiology National Research Council Pisa, Italy

Caroline Morbach MD Yale University New Haven, Connecticut, USA

Ahmad S Omran MD FACC FESC FASE

Loma Linda University Medical Center Loma Linda, California , USA Eisenhower Medical Center Rancho Mirage, California, USA

Consultant Cardiologist Head, Non-Invasive Cardiology Lab King Abdulaziz Cardiac Center–Riyadh Health Affairs–Ministry of National Guard Kingdom of Saudi Arabia

Nagaraja Moorthy MD DM

Jatinder Singh Pabla BSc (Hons) MBBS

Hoda Mojazi-Amiri MD

Assistant Professor Department of Cardiology Sri Jayadeva Institute of Cardiovascular Sciences and Research Bengaluru, Karnataka, India

Hirohiko Motoki MD Cardiovascular Research Imaging Fellow, Cleveland Clinic Foundation, Cleveland, Ohio, USA

Bernhard Mumm President and COO TomTec Imaging Systems GmbH, Edisonstr Unterschleissheim, Germany

Rachel Myers RDCS Allegheny General Hospital Pittsburgh, Pennsylvania, USA

Navin C Nanda MD Distinguished Professor of Medicine and Cardiovascular Disease and Director, Heart Station/Echocardiography Laboratories, University of Alabama at Birmingham and the University of Alabama Health Services Foundation The Kirklin Clinic, Birmingham Alabama, USA, President, International Society of Cardiovascular Ultrasound

Elizabeth Ofili MD MPH FACC Morehouse School of Medicine Chief of Section of Cardiology Associate Dean of Clinical Research Professor of Medicine Atlanta, Georgia, USA

xi

Luc A Pierard MD PhD Department of Cardiology Heart Valve Disease Clinic CHU Sart Tilman, University of Liège, Belgium

Atif N Qasim MD MSCE Assistant Professor of Medicine University of California San Francisco, California, USA

MRCP

Department of Cardiovascular Medicine Northwick Park Hospital, Harrow, UK

Shyam Padmanabhan MD Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Ramdas G Pai MD Professor of Medicine Loma Linda University Medical Center Loma Linda, California, USA

Natesa G Pandian MD Professor, Tufts University School of Medicine, Director, Heart Valve Center Co-Director, Cardiovascular Imaging Center Director, Cardiovascular Ultrasound Research, Tufts Medical Center Boston, Massachusetts, USA

Satish K Parashar MD Metro Heart Institute New Delhi, India

Anita Radhakrishnan MD Fellow, Division of Cardiology Allegheny General Hospital Pittsburgh, Pennsylvania, USA

Peter S Rahko MD Professor of Medicine Division of Cardiovascular Medicine Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA

Rajesh Ramineni MD University of Texas Medical Branch Galveston, Texas, USA

JRTC Roelandt MD Professor of Cardiology Honorary Chairman, Thoraxcentre Erasmus University Medical Centre, Rotterdam The Netherlands

Lindsay Rogers MD

Department of Pediatrics Division of Pediatric Cardiology Vanderbilt University Medical Center Nashville, Tennessee, USA

Heart Center, St Christopher’s Hospital for Children and Section of Cardiology Department of Pediatrics Drexel University, College of Medicine Philadelphia, Pennsylvania, USA

Ashvin K Patel MD

Asad Ullah Roomi MD

University of Wisconsin School of Medicine and Public Health Madison, Wisconsin, USA

Prince Sultan Cardiac Center Military Hospital Riyadh Riyadh, Kingdom of Saudi Arabia

David A Parra MD

xii


José Alberto San Román MD PhD FESCC

Teresa Sevilla MD

Robert J Siegel MD

Hospital Clínico, Universitario de Valladolid, Spain

Hospital Clínico Universitario de Valladolid, Spain

The Heart Institute, Cedars Sinai Medical Center, Beverly Boulevard Los Angeles, California, USA

Emanuele Romeo MD

James Seward MD

Department of Cardiology Second University of Naples Monaldi Hospital, Naples, Italy

Mayo Clinic Rochester, Minnesota, USA

Utpal N Sagar MD Advanced Cardiovascular Imaging Fellow Heart and Vascular Institute Department of Cardiovascular Medicine Cleveland, Ohio, USA

Hamid Reza Salehi MD Research Fellow in Echocardiography Tufts Medical Center Boston, Massachusetts, USA

Ivan S Salgo MD MSc Philips Healthcare Andover, Massachusetts, USA

Giovanni Di Salvo MD King Faisal Specialist Hospital and Research Center Heart Center Riyadh, Saudi Arabia

Benoy Nalin Shah BSc (Hons) MBBS MRCP

Department of Cardiovascular Medicine Northwick Park Hospital Harrow, UK Cardiovascular Biomedical Research Unit Royal Brompton Hospital London, UK National Heart and Lung Institute Imperial College London, UK

Chetan Shenoy MBBS Fellow in Cardiovascular Disease Tufts Medical Center Boston, Massachusetts, USA

Mark V Sherrid MD

Director, Echocardiography Lab Associate Professor of Medicine New York University Langone Medical Center New York, New York, USA

Director, Echocardiography Laboratory Roosevelt Division Program Director, Hypertrophic Cardiomyopathy Program St. Luke's-Roosevelt Hospital Center Professor, Clinical Medicine Columbia University, College of Physicians and Surgeons New York, New York, USA

Nelson B Schiller MD

Savitri Shrivastava MD DM FACC FAMS

Muhamed Saric MD PhD

Professor of Medicine University of California San Francisco UCSF Division of Cardiology Parnassus Avenue San Francisco, California, USA

Roxy Senior MD DM FRCP FESC FACC Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK National Heart and Lung Institute Imperial College, London, UK Department of Cardiovascular Medicine Northwick Park Hospital, Harrow, UK

Satinder P Singh MD FCCP Professor, Radiology and Medicine—Cardiovascular Disease Chief, Cardiopulmonary Radiology Chief, 3D Lab, Director, Cardiac CT Director, Combined Cardiopulmonary and Abdominal Imaging Fellowship Program University of Alabama at Birmingham Birmingham, Alabama, USA

Siddharth Singh MD MS Division of Cardiovascular Disease University of Alabama at Birmingham Birmingham, Alabama, USA

Chittur A Sivaram MD David Ross Boyd Professor Vice Chief of Cardiovascular Section Associate Dean for Continuing Professional Development University of Oklahoma Health Sciences Center Oklahoma City, Oklahama, USA

Sushilkumar K Sonavane MD Assistant Professor Cardiopulmonary Radiology University of Alabama at Birmingham Department Radiology Birmingham, Alabama, USA

Vincent L Sorrell MD

Director Pediatric and Congenital Heart Diseases Fortis Escorts Heart Institute New Delhi, India

Anthony N DeMaria Professor of Medicine, Assistant Chief Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky, USA

Peter Sidarous MD

Jonathan H Soslow MD

Research Associate UC-Irvine School of Medicine Irvine, California, USA

Department of Pediatrics Division of Pediatric Cardiology Vanderbilt University Medical Center Nashville, Tennessee, USA

Khadija Siddiqui DO

Anna Agnese Stanziola MD

Division of Cardiology Department of Medicine University of Texas Medical Branch Galveston, Texas, USA

Clinical and Surgery Department Division of Respiratory Medicine University “Federico II”of Naples Naples, Italy

Contributors

Sharath Subramanian MD

George Thomas MD

Isidre Vilacosta MD PhD FESCC

Medical College of Wisconsin Milwaukee, Wisconsin, USA

Department of Cardiology Saraf Hospital, Kochi, Kerala, India

Lissa Sugeng MD

Wendy Tsang MD

Hospital Clínico San Carlos Madrid, Spain

Associate Professor Director of Yale Echo Lab and YRCG Echo Corelab Section of Cardiovascular Medicine Division of Medicine Yale University School of Medicine New Haven, Connecticut, USA

Jie Sun MD PhD Heart Center, St Christopher’s Hospital for Children and Section of Cardiology Department of Pediatrics Drexel University College of Medicine Philadelphia, Pennsylvania, USA

Aylin Sungur MD

University Health Network, Toronto General Hospital, University of Toronto Toronto, Ontario, Canada

Jeane M Tsutsui MD

Leon Varjabedian MD

Teena Tulaba RDCS

Karina Wierzbowska-Drabik MD

Allegheny General Hospital Pittsburgh, Pennsylvania, USA

Padmini Varadarajan MD Department of Cardiology Loma Linda University and VA Medical Centers, Loma Linda, California, USA

Azhar Supariwala MD

Mahdi Veillet-Chowdhury MD

Division of Cardiology St Luke’s-Roosevelt Hospital Center New York, New York, USA

Stony Brook University Medical Center Health Sciences Center Stony Brook, New York, USA

Department of Cardiology Loma Linda University and VA Medical Centers Loma Linda, California, USA

Kiyoshi Tamura PhD Hitachi Aloka Medical, Ltd. Imai, Ome-Shi, Tokyo, Japan

Rohit Tandon MBBS MD Dayanand Medical College and Hospital Unit, Hero DMC Heart Institute Ludhiana, Punjab, India

University of Buffalo Buffalo, New York, USA

Heart Institute (InCor), The University of São Paulo School of Medicine and Fleury Group, São Paulo, Brazil


Pooja Swamy MD

Victor Vacanti MD

Colette Veyrat MD Centre National de la Recherche Scientifique Honorary Researcher Department of Cardiovascular Medicine L’Institut Mutualiste de Montsouris Boulevard Jourdan, Paris Cedex, France

IB Vijayalakshmi MD DM (Card) FICC

FIAMS FIAE FICP FCSI FAMS DSc

Professor of Pediatric Cardiology Sri Jayadeva Institute of Cardiovascular Sciences and Research Bengaluru, Karnataka, India

University of Buffalo Buffalo, New York, USA

Chair and Department of Cardiology Biegański Hospital Medical University of Lodz Lodz, Poland

Timothy D Woods MD Associate Professor of Medicine and Radiology Medical College of Wisconsin Cardiology Division Milwaukee, Wisconsin, USA

Siu-Sun Yao MD FACC Division of Cardiology Valley Health System Ridgewood New Jersey, USA

Elisa Zaragoza-Macias MD MPH Cardiovascular Diseases Fellow University of Washington Seattle, Washington, USA

xiii

Preface Monumental strides have occurred in the evolution of echocardiography since its first introduction in the 1950s. It began with A-mode and M-mode echocardiography which progressed to real time two-dimensional echocardiography in the 1970s after a hiatus of several years. This development completely revolutionized the field of noninvasive cardiac imaging; and within a few years of its introduction, there were hardly any cardiology divisions in any hospital anywhere in the world which did not own an ultrasound machine. The next few years saw the development of continuous and pulsed wave Doppler and color Doppler flow imaging which provided assessment of cardiac hemodynamics to supplement the structural information obtained using two-dimensional echocardiography. Other advances rapidly followed or occurred concurrently. These included stress echocardiography, transesophageal echocardiography, contrast echocardiography and tissue Doppler and velocity vector imaging. More recently, further innovations were introduced such as live/real time three-dimensional echocardiography and both two-and three-dimensional speckle tracking echocardiography which have obviated some of the limitations of the previous techniques and have further enhanced the clinical usefulness of echocardiography. To this day, echocardiography represents the most useful and most costeffective noninvasive modality available for the assessment of various cardiac disease entities. The development of allied noninvasive technologies like magnetic resonance imaging and computed tomography has further added to the information provided by echocardiography and are useful and important additions to the armamentarium of the cardiologists and other patient care providers in the comprehensive assessment and management of cardiac disease. The aim of the current book is to provide an overview of the subject of clinical echocardiography as it is practiced to-day. Given the many advances that have not only been recently introduced but are also ongoing in this field it would be very difficult for anyone to realistically come up with a comprehensive book on echocardiography but an attempt has been made to cover as many topics as possible in this book. In addition, the supplementary information provided by magnetic resonance imaging and computed tomography is also included in this book. The book consists of a total of 85 chapters organized into seven sections. The first section deals with the basics of ultrasound, Doppler, speckle tracking, three-dimensional echocardiography and instrumentation. A short history of echocardiography and Doppler are also included in this section. The second section consists of various aspects of echocardiography and ultrasound examination. M-mode and two- and three-dimensional transthoracic and transesophageal examination, nonstandard planes, various aspects of Doppler assessment including tissue Doppler, velocity vector and speckle tracking imaging, assessment of endothelial function, contrast echocardiography for evaluation of left ventricular endocardial border opacification and myocardial perfusion, transpharyngeal echo, epiaortic echocardiography and both intracardiac and intravascular ultrasound are dealt with in this section. In addition, examination with a small hand-held ultrasound system, peripheral ultrasound, echocardiographic artifacts, quantification techniques in echocardiography and echocardiography training form a part of this section. Valvular heart disease is covered in the next section. It deals with evaluation of mitral valve disease, mitral regurgitation, aortic stenosis including assessment of low gradient stenosis with preserved left ventricular function, aortic regurgitation, aortic disease, tricuspid and pulmonary valves, pulmonary hypertension, infective endocarditis and prosthetic valves. Rheumatic heart disease is also included in this section. Section 4 deals with two- and three-dimensional echocardiographic assessment of systolic and diastolic function of both left and right ventricles. Newer aspects of structure and function to assess cardiac motion, evaluation of left atrial function, ventricular assist devices, pacemakers and intracardiac defibrillators and use of echocardiography for the assessment of cardiac hemodynamics and guidance of therapy are also included in this section. The next section contains chapters covering ischemic heart disease, coronary arteries and coronary flow reserve,

xvi


different aspects of stress echocardiography including three-dimensional stress echocardiography, obstructive and non-obstructive cardiomyopathies, differentiation of ischemic and nonischemic cardiomyopathy, pericardial disorders and tumors and masses. Section 6 deals with congenital heart disease and consists of chapters on fetal cardiac imaging, M-mode and two- and three-dimensional assessment of pediatric congenital heart disease, ventricular function, adult congenital heart disease and acquired heart diseases in childhood. The final section in the book, Section 7, covers systemic diseases, life-threatening conditions, echocardiography in women and the elderly, echocardiography for the electrophysiologist and lung ultrasound. A separate chapter assesses the future of echocardiography and ultrasound. Lastly, two chapters cover the allied techniques of magnetic resonance imaging and cardiac computed tomographic imaging. A very large number of echocardiographic images and other figures illustrate most of the chapters of the book and six DVDs contain numerous movie clips to supplement the images. These represent a major highlight of the book. All chapters in this book are written by well-known experts in the field of echocardiography and ultrasound. Because of the large number of contributors, some overlap of content and chapters do exist in the book. This has been deliberately not excluded because it provides a different perspective to the reader and also serves to reinforce important concepts and echocardiographic findings. Navin C Nanda MD

Acknowledgments I am most grateful to all the contributors from different countries of the world who have taken valuable time off from their busy schedule to prepare chapters for this book. I am also grateful to the faculty, clinical and research fellows, medical residents, and observers, both past and present, from our institution who have directly or indirectly helped in the preparation of this book. Special mention needs to be made of Kunal Bhagatwala, Nidhi M Karia, Steven Bleich, Aylin Sungur, Tuğba Kemaloğlu Öz, Kruti Jayesh Mehta, Maximiliano German Amado Escañuela and Ming Hsuing for their invaluable help. I wish to express my thanks to the International Society of Cardiovascular Ultrasound and the Indian Academy of Echocardiography for agreeing to have the book under their aegis. Special thanks to all the members of the Indian Academy of Echocardiography including the current President Dr ST Yavagal as well as Drs Satish Parashar, HK Chopra and Rakesh Gupta for their unstinting support of this project. I especially appreciate the constant support and encouragement of Shri Jitendar P Vij (Group Chairman) and Mr Ankit Vij (Managing Director) of M/s Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India, in helping publish this book and also all their associates particularly Ms Chetna Malhotra Vohra (Senior Manager–Business Development) and Ms Saima Rashid (Development Editor) who have been prompt, efficient and most helpful. I also deeply appreciate the help of Lindy Chapman, Administrative Associate at the University of Alabama at Birmingham, who provided excellent editorial and secretarial assistance, and Diane Blizzard, Office Associate, for her help. Last but not least, I appreciate the patience, understanding and support of my wife, Kanta Nanda.

Contents

xix

Contents Volume 1

Section 1: History and Basics 1. History of Echocardiography

3

Fadi G Hage, Anant Kharod, David Daly, Navin C Nanda • • • • • • • • • •

History of Ultrasound 4 The Development of Clinical Cardiac Ultrasound: A-Mode and M-Mode Echocardiography 4 Two-Dimensional Echocardiography 8 Conventional Doppler Ultrasound 9 Color Doppler Ultrasound 11 Contrast Echocardiography 11 Transesophageal Echocardiography 13 Tissue Doppler and Speckle Tracking Imaging 14 Three-Dimensional Echocardiography 14 Perspective 19

2. Early Cardiac Flow Doppler Era: A Key for a New Clinical Understanding of Cardiology

24

Colette Veyrat • The Preflow Doppler Era: Paucity of Existing Noninvasive Tools 25 • Explosive Emergence of the “Flow Concept”, an Indispensable Mutation from Pressure Measurements, which Prepared the Doppler Flow Era 27 • Return to the Doppler Technique in Search of a Noninvasive Tool Documenting the “Flow Concept” 28

3. Basics of Ultrasound

55

Caroline Morbach, Kamran Haleem, Lissa Sugeng • • • • •

General Physics 55 Imaging by Ultrasound 57 Image Optimization and Equipment 60 Artifacts 61 Doppler Ultrasound 63

4. Doppler Echocardiography—Methodology, Application and Pitfalls George Thomas • • • • •

Doppler in Cardiology 65 Doppler Instrumentation 66 Continuous Wave Doppler 68 Pulsed Wave Doppler 69 Color Doppler 71

65

xx


• • • •

Power Doppler 71 Tissue Doppler 72 The Doppler Methodology 72 Information Derived from Doppler 73

5. Basics of 3D Ultrasound

74

Ivan S Salgo, Wendy Tsang, Nicole Bhave, Roberto M Lang • • • • • •

Evolution of 3D Echocardiography 74 Transducer Technology 76 Beam Forming 77 Rendering 78 Limitations in 3D Image Quality 80 3D Echocardiography Quantification 81

6. Speckle Tracking Acquisition: Basics and Practical Tips

87

Willem Gorissen, Navin C Nanda • • • • • • • • • • • • • •

M-Mode (1D Speckle Tracking) 87 Two-Dimensional Speckle Tracking 88 R-R Interval 91 Standard Views 91 Standardization 91 Two-Dimensional Speckle Tracking Limitation 92 Speckle Tracking Versus Tissue Doppler Imaging 92 Tissue Doppler Imaging Versus Speckle Tracking 92 Three-Dimensional Acquisition 92 Multiview Monitoring During Live Acquisition 97 Multiview Orientation 97 Gain Setting 97 Patient Breath-Hold 98 Arrhythmias 98

7. Instrumentation for Transesophageal Echocardiography Including New Technology

99

Ryozo Omoto, Kiyoshi Tamura • • • • • •

Kinds of Transesophageal Echo (TEE) 99 What Makes Image Quality 104 Artifacts 107 Safety Considerations 110 Current and Future Technologies 112 In the Future 116

Section 2: Echocardiography/Ultrasound Examination and Training 8. M-Mode Examination Kamran Haleem, Caroline Morbach, Lissa Sugeng • Historical Perspective 119 • Underlying Concept 119

119

Contents

xxi

• Color M-Mode 120 • Advantages and Disadvantages of M-Mode 120 • Use of M-Mode 121

9. The Complete Transthoracic Echocardiography

132

Rachel Hughes-Doichev, Anita Radhakrishnan, Abid Ali Fakhri Teena Tulaba, Rachel Myers • • • • • • • • •

Getting Started 132 Echocardiographic Imaging Windows and Planes 135 Imaging Modalities 135 Parasternal Window 137 Apical Window 146 Subcostal Window 155 Suprasternal Notch Window 159 Three-Dimensional Echocardiography 159 Left Ventricle Chamber Quantification and Regional Wall Motion Determination 161

10. The Standard Transthoracic Examination: A Different Perspective

164

Atif N Qasim, Nelson B Schiller • Set-Up and Patient Positioning 164 • Imaged Planes 166

11. Nonstandard Echocardiographic Examination

188

Navin C Nanda, Aylin Sungur, Kunal Bhagatwala, Nidhi M Karia, Tuğba Kemaloğlu Öz • • • • • •

Right Parasternal Examination Planes 188 Right and Left Supraclavicular Examination 189 Left Parasternal and Apical Planes for Examination of Coronary Arteries 190 Examination of Left Atrial Appendage 212 Examination from the Back 216 Abdominal Examination 220

12. Technique and Applications of Continuous Transthoracic Cardiac Imaging

224

Premindra PAN Chandraratna, Dilbahar S Mohar, Peter Sidarous • Feasibility of Continuous Cardiac Imaging 224 • Limitations 237

13. The Basics of Performing Three-Dimensional Echocardiography Steven Bleich, Navin C Nanda, Satish K Parashar, HK Chopra, Rakesh Gupta • • • • • • • • • •

3D Technology 240 3D Examination Protocol 241 Left Parasternal Approach 244 Apical Approach 244 Subcostal Approach 244 Suprasternal Approach 244 Supraclavicular Approach 244 Right Parasternal Approach 246 Color Doppler Imaging 248 Advantages/Disadvantages of 3D Echocardiography 262

240

xxii


14. How to do Three-Dimensional Transthoracic Echocardiography Examination

268

Fabrice Larrazet, Colette Veyrat • • • • • • • • • • • •

History 268 Methods for Data Acquisition 268 Left Ventricular Assessment 270 Reproducibility 272 Regional LV Function 276 Aortic Regurgitation 280 Aortic Annulus 280 Mitral Stenosis 280 Mitral Regurgitation 282 Tricuspid Valve Disease 283 Pulmonic Valve Disease 284 Advances in Pediatric and Fetal Cardiac Pathologies 285

15. Point-of-Care Diagnosis with Ultrasound Stethoscopy

291

JRTC Roelandt • • • • • • • • •

Battery-Powered Ultrasound Imagers 291 The Traditional Physical Examination 292 The New Physical Examination 293 Acute Care Environment 294 Screening 294 Preparticipation Screening of Athletes 295 Imaging in Remote Areas and Developing Countries 295 Training Requirements 295 Future Directions 296

16. Spectral Doppler of the Hepatic Veins

299

Bahaa M Fadel, Bader Almahdi, Mohammad Al-Admawi, Giovanni Di Salvo • • • • • • • •

Imaging of the Hepatic Veins 299 Physiological and Other Factors that Affect Hepatic Venous Flow 302 Doppler Pattern of the Hepatic Veins Versus the Superior Vena Cava 304 Transthoracic Echocardiography 304 Transesophageal Echocardiography 305 Technical Considerations 305 Hepatic Venous Flow in Disease States 305 Limitations, Technical Pitfalls and Artifacts 319

17. Spectral Doppler of the Pulmonary Veins Bahaa M Fadel, Bader Almahdi, Mohammad Al-Admawi, Giovanni Di Salvo • • • • • •

Historical Perspective 325 Imaging of the Pulmonary Veins 325 Physiological Factors that Affect Pulmonary Venous Flow 329 Pulmonary Venous Flow in Disease States 331 Limitations and Technical Pitfalls 342 Artifacts 343

325

Contents

18. Tissue Doppler Imaging

xxiii 349

Hisham Dokainish • Technical Considerations 349 • Development of Tissue Doppler Imaging 350 • Current Clinical Uses of TD Imaging 350

19. Speckle Tracking Echocardiography: Clinical Usefulness

360

Shyam Padmanabhan, Siddharth Singh, Navin C Nanda • • • • • • • •

Cardiac Muscular Anatomy, Cardiac Mechanics 360 What is Strain? 362 Two-Dimensional Speckle Tracking Echocardiography (2D STE) 365 Image Acquisition and Processing 367 Clinical Application of 2D STE 367 Three-Dimensional Speckle Tracking Echocardiography (3D STE) 372 Clinical Applications of 3D STE 373 Limitations of Speckle Tracking Echocardiography 374

20. Echocardiographic Assessment of Global and Segmental Function Using Velocity Vector ImagingTM

380

Michael J Campbell, David A Parra, Daniel Forsha, Piers Barker, Jonathan H Soslow • • • •

Application of Velocity Vector Imaging by Age and Disease Group 390 Dyssynchrony, Velocity Vector Imaging Analysis 400 Reproducibility and Correlation Between Vendors 401 Future Directions 404

21. Contrast Echocardiography

416

Jatinder Singh Pabla, Benoy Nalin Shah, Roxy Senior • • • • • • •

What is Ultrasound Contrast? 416 How does Ultrasound Contrast Work? 417 Indications for the Use of Ultrasound Contrast 426 Why Should I Use Ultrasound Contrast Agents? 428 Practical Tips 431 Safety of Ultrasound Contrast Agents 434 Saline Contrast Echocardiography 435

22. Myocardial Perfusion Echocardiography

441

Angele A A Mattoso, Jeane M Tsutsui, Wilson Mathias Jr • Acute Coronary Syndromes 443 • Assessment of Myocardial Viability 443 • Chronic Coronary Artery Disease 443

23. Endothelial Dysfunction Naveen Garg, Kanwal K Kapur • History 450 • Endothelial Functions 450 • Endothelial Dysfunctions 451

449

xxiv


• • • • • • • • • • •

Role of Acetylcholine 451 Shear Stress and Flow-Mediated Dilatation 452 Vasoactive Molecules Involved in Vasoregulation 454 NO Release 455 Methodology for Assessing Endothelial Function 455 Analysis of Shear Stress and Flow-Mediated Dilatation Response 457 Limitations 458 Factors Affecting the Flow-Mediated Dilatation 463 Clinical Utility 465 Other Noninvasive Methods to Assess Endothelial Function 465 Assessment of Endothelial Function and Future Directions 471

24. How to do a Two-Dimensional Transesophageal Examination

480

Andrew P Miller, Navin C Nanda • Patient Selection and Consent 480 • Preparation, Conscious Sedation and Esophageal Intubation 480 • The TEE Examination 481

25. Upper Transesophageal and Transpharyngeal Examination

487

Stephanie El-Hajj, Navin C Nanda, Kunal Bhagatwala, Nidhi M Karia, Fadi G Hage • Technique and Recognition of Vessels 487 • Application 495

26. How to Perform a Three-Dimensional Transesophageal Echocardiogram

507

Elisa Zaragoza-Macias, Michael Chen, Edward Gill • • • •

Three-Dimensional Transesophageal Technology 507 Performing 3D TEE Evaluation 508 Specific Uses of 3D TEE 512 Guidelines and Final Recommendations 514

27. Three-Dimensional Examination to Evaluate Valvular Heart Disease: The Value of an Added Dimension Nina Ghosh, Judy R Mangion • • • • • •

Data Acquisition 515 3D Echo Image Optimization 516 3D Echo of the Mitral Valve 516 3D Echo of the Aortic Valve 520 3D Echo of the Pulmonic Valve 522 3D Echo of the Tricuspid Valve 523

Case Examples of 3D Echo in Valvular Heart Disease 525 • • • • • • •

Case Study 1: Paravalvular Leak Mechanical MV 525 Case Study 2: MV Repair and Aortic Valve Replacement 526 Case Study 3: S/P Cardiac Transplant with Right Heart Failure, Tricuspid Valve Replacement 526 Case Study 4: Flail Middle-Scallop, Posterior Leaflet, MV 526 Case Study 5: Bileaflet MV Prolapse, Moderate to Severe Mitral Insufficiency 527 Case Study 6: Severe Aortic Stenosis, Evaluate for Possible TAVR 527 Case Study 7: Rheumatic Mitral Stenosis 527

515

Contents

xxv

• Case Study 8: S/P Balloon Aortic Valvuloplasty 527 • Case Study 9: Mechanism and Severity of Eccentric Mitral Insufficiency 528 • Case Study 10: Question of Carcinoid Involvement of the Pulmonic Valve 528

28. Three-Dimensional Echocardiographic Guidance of Percutaneous Procedures 531 Muhamed Saric, Ricardo Benenstein • • • • • • •

Fluoroscopy Versus Echocardiography in Guiding Percutaneous Interventions 532 Transseptal Puncture: A Common Element of Many Interventional Procedures 532 Valvular Disease 533 Device Closure of Cardiac Shunts 548 Occlusion of the Left Atrial Appendage 559 Guidance of Electrophysiology Procedures 566 Miscellaneous Procedures 569

29. Three-Dimensional Echocardiography in the Operating Room

577

Ahmad S Omran • • • • • • •

Mitral Valve Disease 577 Aortic Valve Disease 582 Tricuspid Valve Disease 589 Native Valve Endocarditis 597 Prosthetic Valve Dysfunction 605 Cardiac Masses 617 Limitations of 3D TEE, Future Directions 628

30. Epiaortic Ultrasonography

638

Dheeraj Arora, Yatin Mehta • • • • • •

Background for Epiaortic Ultrasonography Examination 638 Indications 638 Epiaortic Probe and Preparation 638 Imaging Views/Planes 639 Role of Epiaortic Ultrasonography in Aortic Pathology 640 Advantages of Three-Dimensions over Two-Dimensions in Epiaortic Ultrasonography 641

31. Intracardiac Echocardiography

643

Krishnaswamy Chandrasekaran, Donald Hagler, James Seward • • • • •

Equipment and the Catheters 643 Imaging Specifications 644 Intracardiac Echocardiography: Clinical Applications 644 Intracardiac Echocardiography during Electrophysiology (EP) Intervention 644 Intracardiac Echocardiography during Structural Intervention 648

32. Intravascular Ultrasound Imaging Sachin Logani, Charles E Beale, Luis Gruberg, Smadar Kort • • • • • • •

Principles of Ultrasound Technology 655 Image Acquisition 655 Intravascular Ultrasound Examination 656 Image Interpretation 657 Utility of Intravascular Ultrasound in Clinical Practice 659 Safety Considerations 661 Future Perspectives 661

655

xxvi


33. Peripheral Vascular Ultrasound

663

Ricardo Benenstein, Muhamed Saric • Ultrasound Diagnosis of Carotid Artery Diseases 663 • Ultrasound Diagnosis of Femoral Access Complications 694

34. Advanced Noninvasive Quantification Techniques in Echocardiography

705

Bernhard Mumm, Navin C Nanda • • • • • •

Technological Background of the Different Advanced Quantification Tools 706 Clinical Applications of Advanced Three-Dimensional Echo Quantification Tools 721 Right Ventricular Quantification 723 Mitral Valve Assessment 725 Aortic Valve Assessment 727 Conclusion and Future Outlook 728

35. Artifacts in Echocardiography

732

Shyam Padmanabhan, Navin C Nanda, Aylin Sungur, Tuğba Kemaloğlu Öz, Kunal Bhagatwala, Nidhi M Karia, Kruti Jayesh Mehta, Rohit Tandon • • • • • • • • • •

Acoustic Shadowing and Acoustic Enhancement 733 Reverberation Artifacts 734 Mirror Image Artifacts 735 Double Image Artifacts 736 Side Lobe Artifact 736 Artifacts Secondary to Use of Electronic Equipment 736 Aliasing 736 Range Ambiguity 736 Artifacts in Three-Dimensional Echocardiography 736 Techniques to Identify and Eliminate Artifacts 737

36. Echocardiography Training

750

Monodeep Biswas, Steven Bleich, Navin C Nanda • • • • •

Training of Noncardiologists 752 Training for Cardiac Sonographers 753 Training in Computed Tomography and Magnetic Resonance Imaging 755 Certification and Maintenance of Proficiency 758 Appropriate Use Criteria 758

Section 3: Valvular Heart Disease 37. Echocardiography in Acute Rheumatic Fever and Chronic Rheumatic Heart Disease IB Vijayalakshmi • • • • • •

Echocardiography in the Diagnosis of Carditis in ARF 765 Chronic Rheumatic Heart Disease 775 Mitral Valve Diseases 775 Mitral Stenosis 776 Mitral Regurgitation 791 Aortic Valve Diseases 802

765

Contents

• • • • •

xxvii

Aortic Stenosis 802 Aortic Regurgitation 806 Tricuspid Valve Diseases 812 Tricuspid Stenosis 812 Tricuspid Regurgitation 813

38. Echocardiographic Assessment of Mitral Valve Disease

826

C N Manjunath, Nagaraja Moorthy, Luis Bowen, Navin C Nanda • • • •

Overview 826 Echocardiographic Assessment of Mitral Stenosis 826 Echocardiographic Assessment of Mitral Regurgitation 847 Assessment of Severity of Mitral Regurgitation 863

39. Mitral Regurgitation

880

Luc A Pierard, Christine Henri, Julien Magne • • • • • • •

Etiology 880 Mechanisms 884 Severity of Mitral Regurgitation 885 Mitral Regurgitation Consequences 889 Sequential Evaluation of Chronic Asymptomatic Mitral Regurgitation 890 Feasibility of Mitral Valve Repair 892 Role of Exercise Echocardiography 892

40. Aortic Stenosis

896

Timothy D Woods, Ashvin K Patel, Sharath Subramanian • • • • • •

Normal Aortic Valve Anatomy 896 Etiology of Aortic Stenosis 897 Echocardiography in Aortic Stenosis 898 Aortic Valve Doppler Examination 904 Use of Stress Echo and Strain in Evaluation of Aortic Stenosis 912 Indications and Appropriateness for Echocardiography in Aortic Valve Stenosis 913

41. Low-Gradient, Severe Aortic Stenosis with Depressed and Preserved Ejection Fraction

919

Eleonora Gashi, Neil L Coplan, Itzhak Kronzon • • • • • • • •

Myocardial Response to Chronic Aortic Stenosis 920 High-Flow, High-Gradient Aortic Stenosis in Setting of Normal Ejection Fraction 920 Low-Flow, Low-Gradient Aortic Stenosis in Setting of Low Ejection Fraction 920 Low-Flow, Low-Gradient Aortic Stenosis in Setting of Normal Ejection Fraction 921 Mechanisms Behind PLFLG-AS 924 Role of Surgical Aortic Valve Replacement (SAVR) in Aortic Stenosis 926 SAVR in Low-Flow, Low-Gradient Aortic Stenosis with Low Ejection Fraction 927 SAVR in Paradoxical Low-Flow, Low-Gradient Aortic Stenosis with Normal Ejection Fraction 927

42. Aortic Regurgitation Arzu Ilercil, Arthur J Labovitz • AR Etiologies 930 • Quantification of AR Severity 936 • Timing of Aortic Valve Surgery 941

930

xxviii


43. Echocardiographic Evaluation of Aortic Disease

945

Martin G Keane • • • • • • •

Echocardiographic Evaluation of the Aorta 945 Aortic Aneurysms 951 Aortic Dissection 954 Common Genetic Syndromes Affecting the Aorta 958 Aortic Atheroma 959 Aortic Trauma and Free Rupture 961 Coarctation of the Aorta 963

44. Transesophageal Echocardiography in the Diagnosis of Aortic Disease

967

Leon J Frazin • The Anatomical Relationship of the Aorta and Esophagus 967 • Imaging the Aorta with Transesophageal Echocardiography 967

45. Echocardiographic Examination of the Tricuspid Valve

984

Poonam Malhotra Kapoor, Kunal Bhagatwala, Nidhi M Karia, Navin C Nanda • • • • • • • •

The Anatomy of Tricuspid Valve (TV) 984 M-Mode Echocardiography 984 Two-Dimensional (2D) Transthoracic Examination 986 Two-Dimensional Transesophageal Examination 988 Three-Dimensional Examination 988 Tricuspid Regurgitation 990 Tricuspid Stenosis 1004 Tricuspid Valve Prolapse: Flail Tricuspid Valve 1007

46. Echocardiographic Assessment of Pulmonary Valve

1031

Hoda Mojazi-Amiri, Padmini Varadarajan, Ramdas G Pai • • • • • • •

Epidemiology 1031 Pulmonary Stenosis 1032 Pulmonary Regurgitation 1036 Echocardiographic Evaluation 1037 Ross Procedure 1038 Postpulmonary Valve Surgery: Monitoring Sequelae 1039 Other Complementary Techniques for Evaluation of Pulmonary Valves 1040

47. Echocardiography in Infective Endocarditis

1042

Javier López, Teresa Sevilla, José Alberto San Román, Isidre Vilacosta, Maximiliano German Amado Escanuela, Kunal Bhagatwala, Nidhi M Karia, Navin C Nanda • • • •

Echocardiographic Findings in Infective Endocarditis 1043 Special Considerations in Patients with Infective Endocarditis 1047 Role of Echocardiography in the Prognostic Stratification of Infective Endocarditis 1050 Indications of Echocardiography in Infective Endocarditis 1058

48. The Role of Echocardiography in Pulmonary Hypertension

1063

Michele D' Alto, Francesco Ferrara, Emanuele Romeo, Anna Agnese Stanziola, Eduardo Bossone • Conventional Echocardiography 1063 • Nonconventional Echocardiography 1070 • Diagnostic Algorithm in Pulmonary Hypertension 1073

Contents

49. Echocardiographic Assessment of Prosthetic Valves

xxix

1080

Aditya Bharadwaj, Pooja Swamy, Gary P Foster, Padmini Varadarajan, Ramdas G Pai • • • •

Types of Prosthetic Valves 1080 Assessment of Prosthetic Valves 1082 Prosthetic Valve Dysfunction 1087 Other Complementary Imaging Modalities 1092

50. Three-Dimensional Transthoracic and Transesophageal Echocardiographic Evaluation of Prosthetic Valves

1094

Steven Bleich, Navin C Nanda • Three-Dimensional Visualization of Prosthetic Valves 1094 • Three-Dimensional Transthoracic Echocardiographic Assessment of Prosthetic Valves 1095 • Three-Dimensional Transesophageal Echocardiographic Assessment of Prosthetic Valves 1100

Volume 2

Section 4: Left and Right Ventricles, Left Atrium, Hemodynamics 51. M-Mode and Two-Dimensional Echocardiographic Assessment of Left Ventricular Systolic Function

1115

Anjlee M Mehta, Navin C Nanda • Visual Estimation of Left Ventricular Systolic Function 1115 • M-Mode and Two-Dimensional Transthoracic Echocardiographic Methods for Assessment of Left Ventricular Systolic Function 1116 • Doppler Echocardiographic Methods of Assessment of Left Ventricular Function 1119 • Two-Dimensional Speckle Tracking Echocardiography and Velocity Vector Imaging 1120 • Myocardial Performance Index 1120 • Contrast Echocardiography in the Assessment of Left Ventricular Systolic Function 1121 • Arterial–Ventricular Coupling 1121 • Three-Dimensional Transthoracic Echocardiography 1122

52. How to Assess Diastolic Function

1124

Hisham Dokainish • Integrating Echocardiographic Variables for Accurate Diagnosis of Diastolic Function 1130 • Novel Imaging Techniques and Future Directions 1131

53. Evaluation of the Right Ventricle Vincent L Sorrell, Steve W Leung, Brandon Fornwalt • • • • • •

General Overview 1134 Right Ventricle Morphology 1135 Echocardiography 1136 Speckle Tracking 1141 Hemodynamics 1143 Other Imaging Modalities 1144

1134

xxx


54. Three-Dimensional Echocardiographic Assessment of LV and RV Function

1149

Aasha S Gopal • 3D Quantitation of the Left Ventricle 1149 • 3D Quantitation of the Right Ventricle 1165

55. Newer Aspects of Structure/Function to Assess Cardiac Motion

1176

Gerald Buckberg, Navin C Nanda, Julien IE Hoffman, Cecil Coghlan • • • • • • • •

Basic Heart Function 1177 State-of-the-Art 1180 Composite of State-of-the-Art Reports 1181 Novel Mechanical and Timing Interdependence between Torsion and Untwisting 1184 The Normal Heart 1185 The Septum 1194 The Right Ventricle 1198 Other Considerations 1198

56. Echocardiography in Assessment of Complications Related to Permanent Pacemakers and Intracardiac Defibrillators

1210

Ahmed Almomani, Khadija Siddiqui, Masood Ahmad • Normal Echocardiographic Findings in Permanent Pacemakers/Implantable Cardioverter-Defibrillators 1210 • Pacemaker and Implantable Cardioverter-Defibrillator-Related Complications 1212 • Tricuspid Regurgitation 1212 • Masses: Lead Infection and Thrombus 1214 • Myocardial Perforation 1215 • Deleterious Effects of Right Ventricular Apical Pacing on Left Ventricular Function 1217

57. Echocardiographic Evaluation of Ventricular Assist Devices

1222

Peter S Rahko • • • • • • • • • • •

Clinical Uses of Ventricular Assist Devices 1224 Reverse Remodeling 1226 Types of Devices 1226 Preoperative Echocardiographic Evaluation 1229 Immediate Postsurgical Evaluation 1234 Serial Changes in Cardiac Structure and Function 1234 Complications of Left Ventricular Assist Devices 1240 Evidence of Underfilling of the Left Ventricle 1246 Optimizing Left Ventricular Assist Device Settings 1248 Explantation 1249 Percutaneous Continuous Flow Devices 1250

58. Echocardiographic Assessment of Left Atrial Function Utpal N Sagar, Hirohiko Motoki, Allan L Klein • • • •

Anatomy 1255 Physiology 1256 Functional Assessment 1257 Left Atrial Pathophysiology 1259

1255

Contents

59. The Use of Echocardiography to Assess Cardiac Hemodynamics and Guide Therapy

xxxi

1264

Roy Beigel, Robert J Siegel • • • • •

Right Atrial Pressure/Central Venous Pressure 1264 Pulmonary Artery Hemodynamics 1269 Left-Sided Filling Pressures 1273 Additional Parameters for Estimation of Left Atrial Pressure 1279 Stroke Volume, Stroke Distance, Cardiac Output, and Systemic Pulmonary Shunts (QP/QS) 1280

Section 5: Ischemic Heart Disease, Cardiomyopathies, Pericardial Disorders, Tumors and Masses

60. Echocardiography in Ischemic Heart Disease

1289

Chetan Shenoy, Hamid Reza Salehi, Francesco F Faletra, Natesa G Pandian • • • • •

Detection of Ischemia 1289 Role in Acute Coronary Syndromes 1292 Mechanical Complications of Myocardial Infarction 1294 Role of Echocardiography in Chronic Ischemic Cardiomyopathy 1298 Novel Echocardiography Techniques in Ischemic Heart Disease 1301

61. Stress Echocardiography

1306

Azhar Supariwala, Siu-Sun Yao, Farooq A Chaudhry • • • •

Fundamentals of Stress Echocardiography 1306 Types of Stress Echocardiography 1307 Interpretation of Stress Echocardiography 1309 Stress Echocardiography: Future Directions 1319

62. Squatting Stress Echocardiography

1323

Premindra PAN Chandraratna, Dilbahar S Mohar, Peter Sidarous • Squatting Echocardiography 1324

63. Three-Dimensional Stress Echocardiography Rajesh Ramineni, Masood Ahmad • • • • • • • • • • •

Two-Dimensional Stress Echocardiography 1328 Three-Dimensional Transducers 1329 Advantages of Three-Dimensions in Stress Imaging 1329 Three-Dimensional Image Acquisition 1330 Three-Dimensional Stress Protocol 1331 Postacquisition Analysis 1331 Review of Studies Comparing Three-Dimensional Stress Echocardiography to Current Standards 1331 Differences between 2DSE and 3DSE in Wall Visualization 1334 Parametric Imaging in Three-Dimensional Stress Echocardiography 1334 Role of Contraction Front Mapping in RT3DSE 1334 Contrast in Three-Dimensional Stress Testing 1335

1328

xxxii


64. Echocardiographic Assessment of Coronary Arteries—Morphology and Coronary Flow Reserve

1337

Karina Wierzbowska-Drabik, Jarosław D Kasprzak • The Assessment of Coronary Morphology and Flow in Transthoracic and Transesophageal Studies 1337 • Visualization of Coronary Arteries 1337 • Distal Coronary Flow and Coronary Flow Reserve 1340 • Congenital Abnormalities of the Coronary Arteries 1343

65. Echocardiography in Hypertrophic Cardiomyopathy

1348

Dan G Halpern, Mark V Sherrid • • • •

Definitions and Types of Hypertrophy 1349 Mid-Left Ventricular Hypertrophic Cardiomyopathy 1356 Differential Diagnosis 1359 Treatment Strategies in Hypertrophic Cardiomyopathy 1361

66. Echocardiographic Assessment of Nonobstructive Cardiomyopathies

1369

Rohit Gokhale, Manreet Basra, Victor Vacanti, Steven J Horn, Aylin Sungur, Robert P Gatewood Jr, Navin C Nanda • • • • • • • • • •

Cardiomyopathies 1369 Dilated Cardiomyopathy (DCM) 1370 Secondary Findings in Dilated Cardiomyopathy 1372 The Role of Echocardiography in Optimizing Heart Failure 1376 Echocardiography in Assessing Ventricular Remodeling 1379 Findings in Dilated Cardiomyopathy Based on Etiology 1379 Restrictive Cardiomyopathy 1397 Other Infiltrative Cardiomyopathies 1405 Infectious and Metabolic Cardiomyopathies 1405 Carcinoid Heart Disease 1407

67. Echocardiographic Differentiation of Ischemic and Nonischemic Cardiomyopathy: Comparison with Other Noninvasive Modalities 1418 Sula Mazimba, Arshad Kamel, Navin C Nanda, Maximiliano German Amado Escanuela, Kunal Bhagatwala, Nidhi M Karia • • • •

Echocardiographic Assessment of Ischemic and Nonischemic Cardiomyopathy 1419 M-Mode Echocardiography 1419 Two-Dimensional/Three-Dimensional/Doppler Echocardiography 1421 Echocardiographic Distinction between Ischemic Cardiomyopathy and Nonischemic Dilated Cardiomyopathy 1425 • Other Noninvasive Imaging Modalities 1425

68. Pericardial Disease Trevor Jenkins, Brian D Hoit • Acute Pericarditis 1436 • Pericardial Effusion 1436

1435

Contents

• • • • • •

xxxiii

M-Mode and Two-Dimensional Echocardiography 1437 Pericardial Tamponade 1438 Constrictive Pericarditis 1444 Effusive-Constrictive Pericarditis 1448 Congenital Anomalies 1448 Multimodality Imaging of the Pericardium 1450

69. Three-Dimensional Echocardiographic Assessment in Pericardial Disorders 1452 O Julian Booker, Navin C Nanda • Two-Dimensional Transthoracic Echocardiography Versus Three-Dimensional Transthoracic Echocardiography in Pericardial Effusion 1453 • Two-Dimensional Transthoracic Echocardiography Versus Three-Dimensional Transthoracic Echocardiography in Constriction 1456 • Two-Dimensional Transthoracic Echocardiography Versus Three-Dimensional Transthoracic Echocardiography in Pericardial Masses 1458

70. Echocardiographic Assessment of Cardiac Tumors and Masses

1462

Leon Varjabedian, Jennifer K Lang, Abdallah Kamouh, Steven J Horn, Tuğba Kemaloğlu Öz Aylin Sungur, Kruti Jayesh Mehta, Kunal Bhagatwala, Nidhi M Karia Maximiliano German Amado Escañuela, Robert P Gatewood Jr, Navin C Nanda • • • •

Echocardiographic Assessment of Cardiac Tumors and Masses 1462 Primary Benign Cardiac Tumors 1464 Malignant Primary Cardiac Tumors 1484 MICE 1511

Section 6: Congenital Heart Disease 71. Fetal Cardiac Imaging

1527

Aarti H Bhat • • • • • • •

Scope of Fetal Cardiology 1527 Indications for Fetal Cardiac Evaluation 1528 Fetal Physiology 1528 Indications for Fetal Echocardiography 1529 Extracardiac Reasons and Associations for Fetal Heart Disease 1529 Fundamentals of Fetal Cardiac Imaging 1530 Case Studies 1556

72. M-mode and Two-Dimensional Echocardiography in Congenital Heart Disease Neeraj Awasthy, Savitri Shrivastava Part 1: Basics of Imaging and Sequential Segmental Analysis 1562

• • • •

Patient Preparation 1562 Imaging 1563 Dextrocardia 1570 Principles of Sequential Chamber Analysis 1575

1561

xxxiv


Part 2: Left-to-Right Shunts: Atrial Septal Defect, Ventricular Septal Defect, Patent Ductus Arteriosus, and Aortopulmonary Window 1582

• • • • • •

General Features: Shunt Lesions 1582 Atrial Septal Defects 1585 Ventricular Septal Defect 1591 Patent Ductus Arteriosus 1599 Aortopulmonary Window 1602 Gerbode Defect 1603

Part 3: Atrioventricular Septal Defects 1604 Part 4: Congenital Left Ventricular and Right Ventricular Inflow Anomalies 1610

• Congenital Anomalies of Mitral Valve 1610 • Congenital Abnormalities of Tricuspid Valve 1616 Part 5: Left Ventricular Outflow Tract Obstruction 1618

• • • • • •

Valvular Aortic Stenosis 1618 Subvalvular Aortic Stenosis 1624 Supravalvular Aortic Stenosis 1626 Aortic Regurgitation 1628 Sinus of Valsalva Aneurysm 1630 Aortocameral Communications 1632

Part 6: Echocardiographic Anatomy of Tetralogy of Fallot with Pulmonary Stenosis 1633

• Aortic Override 1633 • Double Outlet Right Ventricle 1644 • Truncus Arteriosus 1650 Part 7: Complete Transposition of Great Arteries 1653

• Transposition of Great Vessels (TGA) 1653 Part 8: Atrioventricular and Ventriculoarterial Discordance 1664 Part 9: Pulmonary Veins 1670

• • • •

Normal Flow Pattern of Pulmonary Veins 1670 Anomalies of Pulmonary Veins 1672 Total Anomalous Pulmonary Venous Connection 1673 Anomalies of Systemic Veins 1678

Part 10: Imaging of Coronary Anomalies and Pulmonary Arteries 1684

• Coronary Artery Anomalies 1684 • Coronary Arteriovenous Fistula 1688 • Coronary Aneurysms 1688 Part 11: Echocardiographic Evaluation of Aortic Arch and Its Anomalies 1690

• • • •

Abnormal Formation of Arch 1690 Coarctation of Aorta (CoA) 1692 Interruption of Aortic Arch 1694 Aortic Aneurysm 1695

Part 12: Univentricular Heart and Heterotomy Syndrome 1696

• Univentricular Atrioventricular Connections 1697 • Tricuspid Atresia 1700

Contents

xxxv

• Mitral Atresia and Hypoplastic Left Heart Syndrome 1701 • Heterotaxy Syndrome 1704

73. Real Time 3D Echocardiography for Quantification of Ventricular Volumes, Mass and Function in Children with Congenital and Acquired Heart Diseases 1721 Shuping Ge, Jie Sun, Lindsay Rogers, Rula Balluz • • • •

Left Ventricular Volumes, Ejection Fraction, and Mass 1722 Right Ventricular Volumes, Ejection Fraction, and Mass 1723 Single Ventricular Volumes, Ejection Fraction, and Mass 1725 Three-Dimensional Analysis of Regional Wall Motion, Synchrony, and Strain 1726

74. Three-Dimensional Echocardiography in Congenital Heart Disease

1733

Steven Bleich, Gerald R Marx, Navin C Nanda, Fadi G Hage • • • • • • • • • • •

Shunt Lesions/Septal Defects 1733 Common Atrium 1747 Aortopulmonary Window 1751 Patent Ductus Arteriosus (PDA) 1751 Conotruncal Anomalies 1754 Outflow Tract Obstruction 1766 Aortic Arch Anomalies 1770 Atrial and Atrioventricular Valve Abnormalities 1773 Other Abnormalities 1776 Double Outlet Right Ventricle 1779 Sinus of Valsalva Aneurysm 1784

75. Echocardiography in the Evaluation of Adults with Congenital Heart Disease

1791

Reema Chugh • • • •

Key Concepts of Echocardiography in Adults with Congenital Heart Disease 1793 Simple Congenital Heart Defects in Adults 1798 Valvular Disease 1813 Complex Congenital Heart Defects 1826

76. Echocardiographic Evaluation for Acquired Heart Diseases in Childhood Jie Sun, Rula Balluz, Lindsay Rogers, Shuping Ge • • • • • • • •

Infective Endocarditis 1856 Modified Duke Criteria for the Diagnosis of Infective Endocarditis 1857 Echocardiographic Findings 1857 Complications of Infective Endocarditis 1859 Rheumatic Heart Disease 1859 Jones Criteria, Updated 1992 1859 Kawasaki Disease 1861 Coronary Ectasia and Aneurysms by Echocardiography 1861

1856

xxxvi


Section 7: Miscellaneous and Other Noninvasive Techniques 77. Echocardiography in Systemic Diseases

1867

Mahdi Veillet-Chowdhury, Smadar Kort • • • • • • • • • • •

Systemic Lupus Erythematosus 1867 Rheumatoid Arthritis 1868 Hypereosinophilic Syndrome 1868 Systemic Sclerosis 1869 Renal Disease 1871 Amyloidosis 1872 Carcinoid 1874 Chagas Disease 1875 Sarcoidosis 1876 Thyroid Disorders 1879 Nutritional Deficiency 1880

78. Echocardiography in Women

1886

Jennifer Kiessling, Navin C Nanda, Tuğba Kemaloğlu Öz, Aylin Sungur, Kunal Bhagatwala, Nidhi M Karia • • • • • •

Differences in Echocardiographic Measurements and Technical Considerations 1886 Structural Heart Disease: MVP, Mitral Stenosis, and Mitral Annular Calcification 1888 Ischemic Heart Disease/Stress Echocardiography/Polycystic Ovarian Syndrome 1889 Takotsubo Cardiomyopathy 1899 Congenital Heart Disease 1900 Echocardiography in Pregnancy, Peripartum Cardiomyopathy, Fetal Echocardiography 1902

79. Echocardiography in the Elderly

1921

Gopal Ghimire, Navin C Nanda, Kunal Bhagatwala, Nidhi M Karia • • • • • • • • •

Aortic Atherosclerosis and Penetrating Aortic Ulcer 1921 Aortic Valve Sclerosis 1923 Aortic Stenosis 1924 Aortic Aneurysm 1934 Aortic Dissection 1937 Left Ventricular Mass, Dimensions, and Function 1942 Echocardiography in Stroke Patients: Assessment of Coronary Stenosis 1943 Mitral Annular Calcification 1946 Prosthetic Valves 1948

80. How to do Echo for the Electrophysiologist Chittur A Sivaram • • • • • • •

Echocardiography in Supraventricular Tachycardia 1957 Left Atrium 1960 Atrial Septum 1962 Pulmonary Veins 1963 Inferior Vena Cava 1964 Echocardiography in Ventricular Tachycardia 1966 Echocardiography in Cardiac Implantable Electronic Devices 1967

1957

Contents

81. Echocardiography in Life-Threatening Conditions

xxxvii

1969

Rachel Harris, Elizabeth Ofili • • • • • • • • • • • •

Chest Trauma 1969 Blunt Chest Trauma 1969 Penetrating Chest Trauma 1972 Acute Mitral Regurgitation 1972 Acute Severe Aortic Regurgitation 1972 Aortic Dissection 1974 Debakey Classification 1974 The Stanford Classification 1974 Pulmonary Thromboembolic Disease 1976 Air Embolism 1977 Hypovolemia 1977 Large Intracardiac Thrombus 1978

82. Lung Ultrasound in Cardiology

1982

Luna Gargani, Eugenio Picano • • • • • • • • •

Physical and Physiological Basis of Lung Ultrasound 1982 Methodology 1983 Pulmonary Interstitial Edema 1984 Pleural Effusion 1985 Pulmonary Embolism 1985 Acute Respiratory Distress Syndrome 1986 Pneumothorax 1986 Cardiopulmonary Ultrasound: An Integrated Approach 1987 Limitations 1987

83. The Future of Echocardiography and Ultrasound

1990

David Cosgrove • • • • • • •

Plane Wave Ultrafast Imaging 1990 Trends in Scanners 1991 Doppler 1993 Microbubbles 1993 Elastography 1994 Light and Sound 1995 Therapeutic Applications of Ultrasound 1996

84. A Primer on Cardiac MRI for the Echocardiographer Madhavi Kadiyala, Aasha S Gopal • • • • • • • •

Quantitative Left and Right Ventricular Assessment 1998 Strain Assessment 1999 Left Ventricular Structure 2000 Myocarditis and Sarcoidosis 2004 Cardiac Hypertrophy 2006 Cardiomyopathies 2008 Velocity Mapping, Flow and Shunt Assessment 2008 Valvular Heart Disease and Prosthetic Valves 2009

1998

xxxviii


• • • •

Pericardial Disease 2014 Normal Variants and Masses 2016 Limitations of Cardiac MRI and CT 2017 Glossary of Cardiac MRI Sequences 2020

85. Cardiac CT Imaging

2023

Satinder P Singh, Sushilkumar K Sonavane • • • • • • • • • • • • •

Challenges for Cardiac Computed Tomography 2024 Radiation Dose 2025 Patient Selection 2027 Technique 2027 Image Postprocessing 2028 Image Analysis 2032 Pitfalls and Artifacts 2034 Diagnostic Accuracy of Coronary Computed Tomography Angiogram 2040 Coronary Plaque 2041 Prognostic Information from Coronary Computed Tomography Angiogram 2042 Cardiac Function 2042 Myocardial Perfusion 2042 How to Improve Accuracy of Computed Tomography Angiogram in Determining Flow Limiting Disease 2044 • Clinical Indications 2044 Index I-i

SECTION 4 Left and Right Ventricles, Left Atrium, Hemodynamics

Chapters Chapter 51 M-Mode and Two-Dimensional Echocardiographic Assessment of Left Ventricular Systolic Function Chapter 52 How to Assess Diastolic Function Chapter 53 Evaluation of the Right Ventricle Chapter 54 Three-Dimensional Echocardiographic Assessment of LV and RV Function Chapter 55 Newer Aspects of Structure/Function to Assess Cardiac Motion Chapter 56 Echocardiography in Assessment of Complications Related to Permanent Pacemakers and Intracardiac Defibrillators

Chapter 57 Echocardiographic Evaluation of Ventricular Assist Devices Chapter 58 Echocardiographic Assessment of Left Atrial Function Chapter 59 The Use of Echocardiography to Assess Cardiac Hemodynamics and Guide Therapy

CHAPTER 51 M-Mode and Two-Dimensional Echocardiographic Assessment of Left Ventricular Systolic Function Anjlee M Mehta, Navin C Nanda

Snapshot ¾¾ Visual Estimation of Left Ventricular Systolic Function ¾¾ M-Mode and Two-Dimensional Transthoracic Echocar-

diographic Methods for Assessment of Left Ventricular Systolic Function ¾¾ Doppler Echocardiographic Methods of Assessment of Left Ventricular Function ¾¾ Two-Dimensional Speckle Tracking Echocardiography and Velocity Vector Imaging

INTRODUCTION The evaluation of left ventricular systolic function by echocardiography has undergone many recent advance ments. Assessment of ejection fraction as a surrogate for left ventricular systolic function is one of the primary clinical questions for which echocardiograms are obtained. A review of methodologies for determining ejection fraction and/or left ventricular function by M-mode and two-dimensional (2D) echocardiography allows for a better understanding of advantages, disadvantages, and appropriate indications for echocardiographic evaluation of left ventricle (LV) systolic function.

¾¾ Myocardial Performance Index ¾¾ Contrast Echocardiography in the Assessment of Left

Ventricular Systolic Function ¾¾ Arterial–Ventricular Coupling ¾¾ Three-Dimensional Transthoracic Echocardiography

VISUAL ESTIMATION OF LEFT VENTRICULAR SYSTOLIC FUNCTION Visual estimation of LV ejection fraction, in the eyes of an experienced echocardiographer, is a quick method for determination of systolic function and is widely used to help make immediate decisions in clinical settings. A framework for evaluation involving division of the LV into 16 segments was proposed by the American Society of Echocardiography in 1989. In this model, the LV is divided into a basal level, mid (or papillary) level, and apical level. There are six segments at both basal and midventricular levels, and four segments at the apex. In 2002, the

1116

Section 4: Left and Right Ventricles, Left Atrium, Hemodynamics

Fig. 51.1: Seventeen-segment model with correspondence to coronary artery distribution. (LAD: Left anterior descending artery; LCX: left circumflex artery; RCA: Right coronary artery). Source: Reproduced with permission from Pereztol-Valdes O, Candell-Riera J, et al. Correspondence between left ventricular 17 myocardial segments and coronary arteries. Eur Heart J. 2005(26):2637–43.

American Heart Association Writing Group on Myocardial Segmentation and Registration for Cardiac Imaging added a 17th segment encompassing the apical cap, the segment beyond the end of the LV cavity1 (Fig. 51.1). This model allows for segmental determination of regional wall motion abnormalities and utilizes a scoring system based on the motion and systolic thickening of each segment. The walls are evaluated in multiple echocardiographic views including a parasternal long-axis ([PLAX], or apical 3-chamber [A3Ch]/apical long-axis [ALA]), parasternal short-axis (PSAX), apical 4-chamber (A4Ch), and apical 2-chamber (A2Ch) view for correlation. Each segment can be scored from 1 to 5 with the following definitions: 1 = normal or hyperkinesis, 2 = hypokinesis, 3 = akinesis (negligible thickening), 4 = dyskinesis (paradoxical systolic motion), and 5 = aneurysmal (diastolic deformation). The score for each segment is added up to give a total score. This score is then divided by the number of segments to create a wall motion index score. A normal ventricle has a wall motion score of 1.1,2 The blood supply from a particular coronary artery to each segment can also be defined. In general, segments 1, 2, 7, 8, 13, 14, and 17 are generally supplied by the left anterior descending artery, segments 3, 4, 9, 10, and 15

by the right coronary artery (if dominant), and segments 5, 6, 11, 12, and 16 by the left circumflex artery. As a result, if regional wall motion abnormalities are involved, describing the segments involved can allow one to surmise which epicardial coronary vessel may be involved (Fig. 51.2).1,2

M-MODE AND TWO-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHIC METHODS FOR ASSESSMENT OF LEFT VENTRICULAR SYSTOLIC FUNCTION The Teichholz formula using M-mode echocardiography was one of the earliest methods developed for assessment of left ventricular ejection fraction (LVEF). In a PLAX view, inferior and lateral to the mitral valve chordae, measurements of the left ventricular end-diastolic internal diameter and the left ventricular end-systolic internal diameter are made. These measurements are then used to calculate end-diastolic and end-systolic volumes, and the difference between these two volumes divided by the enddiastolic volume can be used to calculate the LVEF.3

Chapter 51: M-Mode and Two-Dimensional Echocardiographic Assessment of Left Ventricular Systolic Function

1117

Fig. 51.2: Typical distributions of the right coronary artery (RCA), the left anterior descending (LAD), and the circumflex (CX) coronary arteries. The arterial distribution varies between patients. Some segments have variable coronary perfusion. J Am Soc Echocardiogr. 2005;18(12):1440–63.

M-mode is also used to obtain the E point septal separation (EPSS), an indirect estimation of global LV function. In the setting of LV dysfunction, there is increased separation between the E point (peak of mitral valve opening) and the ventricular septum. With LV chamber enlargement and dysfunction, the mitral valve is shifted further away from the septum and there is reduced transmitral flow (and reduced stroke volume) relative to chamber size. Typically, an EPSS > 1 cm is considered abnormal.4 Using the Quinones method, measurements are taken at several minor-axis locations of the LV in three 2D echocardiographic views (PLAX, A4Ch, and ALA views). The minor-axis measurement locations in the PLAX view are at the base and midcavity levels. In the A4Ch and ALA views, measurements are taken at the upper third, middle third, and lower thirds of the LV in end-systole and end-diastole. The contribution of the apex to the LVEF is made by a qualitative assessment of apical wall motion abnormalities.5

The Baran, Rogal, and Nanda method for quantification of LVEF, in the absence of wall motion abnormalities, requires end-systolic and end-diastolic measurements of the LV minor axis at the midventricular level and the LV major axis from the apex to the base of the LV. These values are obtained in an A4Ch view (Fig. 51.3). End-diastolic and end-systolic volumes are then calculated using a modified cylinder–ellipse formula in which the LV is assumed to be a combination of a cylinder and prolate ellipse (Fig. 51.4). If wall motion abnormalities are present, then measurement of the minor axes at three equidistant points that divide the LV into three regions are obtained. Each region contributes one-third to the total ejection fraction and the chance of including wall motion abnormalities in one of the regions is increased. The total LVEF is an average of the LVEFs obtained from each of the three regions.6 Another method for assessing left ventricular systolic function is to calculate a fractional area change. Measure ments of minor axis dimensions are taken from M-mode echocardiograms obtained with 2D echocardi ographic

1118


Fig. 51.3: Apical four-chamber view of a normal heart at endsystole and end-diastole. In method A, left ventricular (LV) minor axis D is measured at end-systole and end-diastole at the midventricular cavity level. The left ventricular major axis is measured from the apex of the left ventricle to the base of the mitral valve. In method B, measurements of the regional left ventricular minor axes, D1, D2, and D3 are measured at three equidistance points at the upper, middle, and lower third of the left ventricular cavity at end-systole and end-diastole of the same cardiac cycle. The major axis L is measured as before. Directions I, L, R, and S are inferior, left, right, and superior, respectively. (LA: Left atrium; RA: Right atrium; RV: Right ventricular). Source: Reproduced with permission from Baran AO, et al. Ejection fraction determination without planimetry by two-dimensional echocardiography: a new method. J Am Coll Cardiol. 1983;1:1471–8.

guidance. The left ventricular internal dimension in diastole (LVIDd) and left ventricular internal dimension in systole (LVIDs) are used in the formula for fractional shortening, measured at the endocardium (FSendo [%]) such that, FSendo = 100 × (LVIDd − LVIDs)/(LVIDd).7 Unfortunately, fractional shortening at the endoc ardium is affected by changes in left ventricular geometry and loading conditions. Another parameter called midwall fractional shortening (MWFS) is less influenced by left ventricular geometry and has been shown to be useful in detection of early systolic dysfunction in hypertensive patients with concentric left ventricular hypertrophy.7 MWFS, unlike FSendo, does not assume uniformity of systolic thickening throughout the myocardium, and is therefore less likely to overestimate contractile function. In reality, inner wall (subendocardial) and outer wall (epicardial) thickening fractions are not equal, and the inner wall contributes more to systolic thickening than the outer wall.8 This is more pronounced in conditions with increased relative wall thickness/altered left ventricular

Fig. 51.4: Modified cylinder–ellipse formula. A, cross-sectional area of cylinder (hatched); (D: Diameter of circle A; L: Length of entire object; LVV: Left ventricular volume). Source: Reproduced with permission from Baran AO, et al. Ejection fraction determination without planimetry by two-dimen sional echocardiography: a new method. J Am Coll Cardiol. 1983;1:1471–8.

wall geometry, such as hypertrophied hearts. In addition to the M-mode measurements used in FSendo, the MWFS also uses measurements of septal wall thickness at diastole (SWTd) and posterior wall thickness (PWTd) at diastole and incorporates a separate equation for the inner shell (inner wall) with the following formulas.7,8 Inner shell = ([LVIDd + SWTd/2 + PWTd/2]3 – LVIDd3 + LVIDs3)1/3−LVIDs MWFS= ([LVIDd ± SWTd/2 ± PWTd/2] –[LVIDs ± inner shell]) (LVIDd + SWTd/2 + PWTd/2) × 100 The biplane method of discs, or modified Simpson’s rule, recommended by the American Society of Echocardiography is one of the most commonly applied 2D techniques for obtaining the left ventricular volumes used in calculating an LVEF. The left ventricular endocardial border is traced during end-diastole and end-systole in orthogonal planes that include the apex (e.g. A4Ch and A2Ch views; Fig. 51.5). The ventricle is then divided, along the long axis, into a series of ellipsoid discs of equal height (Fig. 51.6). Computer software then determines the volume of each disc (height × disc area). All the volumes are added to obtain the total LV volumes in systole and diastole and allow for calculation of the LVEF (EDV − ESV/EDV). Limitations of the biplane method of discs include endocardial dropout and apical foreshortening that result in incorrectly small ventricular volumes. It also assumes


1119

Fig. 51.6: Use of Simpson’s rule. Using this rule, the volume of left ventricle is usually calculated by approximating areas along the apical axis by circles and employing axial integration. Source: Reproduced with permission from Ghosh A, Nanda NC, Maurer G. Three-dimensional reconstruction of echocardiographic images using the rotation method. Ultrasound Med Biol. 1982;8(6);655–61.

DOPPLER ECHOCARDIOGRAPHIC METHODS OF ASSESSMENT OF LEFT VENTRICULAR FUNCTION Fig. 51.5: Two-dimensional measurements for volume calculations using biplane method of disks (modified Simpson’s rule) in apical four-chamber (A4C) and apical two-chamber (A2C) views at left ventricular end-diastole (LV EDD) and at left ventricular endsystole (LV ESD). Papillary muscles should be excluded from the cavity in the tracing. Source: Reproduced with permission from Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am SocEchocardiogr. 2005;18(12):1440–63.

that the ventricle is ellipsoidal, which is not always the case (e.g. LV aneurysm). Poor acoustic windows, as is commonly seen in obese, ventilated, or severe chronic obstructive pulmonary disease (COPD) patients, can also make accurate endocardial tracing very difficult. Calculation of a sphericity index is another method that has been used as a marker of left ventricular dysfunction. The sphericity index is the ratio of the LV long-axis dimension and LV short-axis dimension. With negative LV remodeling that occurs in dilated cardiomyopathies, heart failure, myocardial infarcts, and valvular regurgitation, the LV adapts by becoming more spherical. A normal elliptical LV has a sphericity index of ≥ 1.5.9 As the heart becomes more spherical, this value decreases and approaches one signifying a more spherical LV.

Tissue Doppler Imaging Tissue Doppler imaging (TDI) is based on the principle that myocardial velocities, like blood flow velocities, can be differentiated based on their different amplitudes and Doppler frequencies. The peak systolic ejection velocity represented by the S’-wave on velocity tracings is obtained by placing a sample volume 1 cm above (apical) the medial (septal) side of the mitral annulus and obtaining the tissue velocity as the LV moves toward the apex in systole.7 When the LV is in the early filling phase of diastole and moving away from the apex, this velocity is represented by the E’-wave on velocity tracings. The A’-wave velocity is obtained during late diastole as the atria contract and the LV moves away from the apex.7 These waves represent the longitudinal motion of the LV (base to apex shortening). The contribution of longitudinal fiber shortening and myocardial contractile velocity to left ventricular function forms the basis for analysis of the mitral annular descent velocity by tissue Doppler echocardiography. 2D echocardiography guides placement of the M-mode cursor at the mitral annulus at two sites in the A4Ch, A2Ch, and ALA views.10 The maximal color-coded velocity toward the transducer during left ventricular ejection is the peak mitral annular descent velocity. This velocity is independent of endocardial definition, but only looks at longitudinal movement of the LV walls during systole and is influenced by loading conditions and heart rate. Values of < 7 cm/s suggest LV dysfunction.10

1120


Fig. 51.7: Tei’s Index. Time a is the interval between cessation and onset of mitral inflow. It includes isovolumic contraction time (ICT), ejection time (ET), and isovolumic relaxation time (IRT). Left ventricular ejection time b is the duration of the left ventricular outflow velocity profile left ventricle (LV) outflow. The index of combined left ventricular systolic and diastolic function (the sum of isovolumic contraction time and isovolumic relaxation time divided by ejection time) is calculated as (a − b)/b.

TWO-DIMENSIONAL SPECKLE TRACKING ECHOCARDIOGRAPHY AND VELOCITY VECTOR IMAGING In addition to inward and longitudinal motion, the LV also rotates and twists during the cardiac cycle. To quantify the complexity of cardiac motion, a technique called speckle tracking has been developed. Speckles are small groups of myocardial pixels created by the interaction between ultrasound beams and the myocardium.11 Many vendors have developed algorithms for tracking these speckles. Speckle tracking measures aspects of strain, or myocardial deformation, that occur during the cardiac cycle. Radial strain (thickening of the myocardium during the inward motion of the ventricle), longitudinal strain (percentage decrease in length of the myocardium during systole as the base moves toward the apex), and circumferential strain (change in length along the circumferential perimeter) can be assessed.11 In addition to measuring strain and strain rate, speckle tracking also assesses the rotation, twist, and

torsion of the heart. Rotation is defined as the movement of the heart in relation to an axis through the middle of the LV cavity from the apex to the base. Twist is the difference between the rotation of the apex and the base. Torsion is defined as the twist normalized to the length of the LV cavity (i.e. twist divided by the vertical distance between the apex and base).11 There are many ongoing studies showing that changes in these parameters are useful in subclinical detection of systolic dysfunction prior to a visual or measured reduction in LVEF.11 Velocity vector imaging also uses speckle tracking and incorporates this tracking into velocity vectors taken from the LV endocardium and epicardium to follow the direction of the LV myocardium. Unlike for TDI, where the myocardial velocities being interrogated must be from tissue moving parallel to the ultrasound beam (only movements toward and away from the probe), speckle tracking and velocity vector imaging are not limited by the angle at which velocities are obtained and can better account for movements of the myocardium in multiple directions.11 A more detailed description of these modalities and their use assessing systolic and diastolic left ventricular dysfunction can be found in other chapters of this book.

MYOCARDIAL PERFORMANCE INDEX Myocardial performance index, or the Tei’s Doppler index, is the sum of isovolumic contraction time (ICT) and isovolumic relaxation time (IRT) divided by ejection time (ET) and, as such, reflects global (combined systolic and diastolic) cardiac function.12 It provides a measure of ventricular function independent of ventricular geometry. The ICT corresponds to the interval between mitral valve closure and aortic valve opening as measured by pulsed Doppler from the apical position. Physiologically, this correlates with influx of calcium into the mycoplasma.12 The IRT is the interval between aortic valve closure and onset of mitral valve opening and represents the removal of calcium from the myoplasm by calcium-ATPases.12 The ejection time is the interval from the onset to the end of the LV outflow velocity pattern13 (Fig. 51.7). The presence of arrhythmias including atrial fibrillation, frequent atrial and ventricular ectopy, and tachycardias limit the application of the Tei-index. Pseudo normalization of the index also limits its applicability in patients with restrictive filling patterns.14


A

1121

B

Figs 51.8A and B: Contrast echocardiography. (A) Precontrast. The left ventricle (LV) cavity shows multiple trabeculations (arrowhead) in the apex consistent with noncompaction. LV endocardial border is not well visualized in this area; (B) Postcontrast. Following injection of the contrast agent, the LV cavity is completely filled with contrast echoes, resulting in complete delineation of the endocardium.

CONTRAST ECHOCARDIOGRAPHY IN THE ASSESSMENT OF LEFT VENTRICULAR SYSTOLIC FUNCTION Commercially available echo contrast agents are widely used to assist in determination of left ventricular systolic function and evaluation of cardiac chambers and myocardial perfusion. In patients with poor acoustic windows, contrast can be given to help enhance detection of the endocardial border and result in more accurate visual estimates of left ventricular systolic function and measurements of left ventricular volumes. Echo contrast agents consist of reflective microbubbles. They are injected intravenously and pass through right heart, the pulmonary circulation, and into the left side of the heart, where they opacify the left heart chambers and help delineate the endocardial borders. The technique is similar to the more invasive left ventriculogram obtained by injection of contrast during left heart catheterization15,16 (Figs 51.8A and B). Other features that can be adjusted to improve contrast opacification include harmonic imaging and low mechanical index imaging. With these advances, contrast echocardiography provides improved endocardial border imaging, resulting in better detection of wall motion abnormalities, ventricular volume, and ejection fraction. The result is a more accurate estimate of LV systolic function.

ARTERIAL–VENTRICULAR COUPLING The concept of arterial–ventricular coupling (EA/ELV) looks at how properties of the arterial system affect the function of the LV. Several studies have looked at how effective arterial elastance (EA, arterial load) and left ventricular end-systolic elastance (ELV, LV performance) relate and affect cardiac performance especially in conditions where the arterial tree becomes thicker and stiffer like aging, heart failure, and hypertension.17 EA is calculated as end-systolic pressure (ESP) divided by stroke volume (SV) and serves as an index of the vascular load on the LV. ESP is estimated as systolic blood pressure times 0.9 and SV is EDV − ESV as obtained from 2D/Doppler echo methods. ELV is noninvasively calculated using a modified single-beat method to estimate end-systolic elastance from arm-cuff pressures (systolic and diastolic BP), echoDoppler SV, echo-derived ejection fraction, and estimated normalized ventricular elastance at arterial end-diastole. It represents a relatively load-independent measure of LV performance. Arterial–ventricular coupling is evaluated as the ratio of these values (EA/ELV) and maximal efficiency is attained when EA/ELV approaches 0.5.17 In states of elevated afterload (e.g. aging, heart failure, and hypertension), there is increased total peripheral resistance, left ventricular concentric remodeling, inefficient arterial–ventricular coupling, and ultimately, impaired LV function.18,19

1122


A community-based study by Redfield et al. speculated that an increase in heart failure with preserved ejection fraction (HFnlEF) especially amongst elderly women, may be related to maintenance of optimal arterial– ventricular coupling.20 In an effort to maintain stroke volume in the setting of higher arterial elastance as a result of aging, there is an increase in left ventricular systolic stiffness. Unfortunately, increases in these parameters are not without consequence. Redfield et al. note that altered LV chamber geometry (e.g. hypertrophy, concentric remodeling, or fibrosis) to maintain arterial– ventricular coupling and resultant impaired LV relaxation (diastolic dysfunction) could contribute to the increase in HFnlEF they observed in elderly women.20 A study by Lam et al also noted an increase in arterial elastance and left ventricular end-systolic elastance in hypertensive and HFnlEF patients as compared to healthy controls.21

THREE-DIMENSIONAL TRANS THORACIC ECHOCARDIOGRAPHY With 2D transthoracic echocardiography (2D TTE), only one slice of the LV can be obtained at a time. Obtaining other slices to fully examine the LV requires moving the transducer and adjusting the angle of the transducer in various positions. With three-dimensional transthoracic echocardiography (3D TTE), the transducer emits hundreds of ultrasound waves through the heart allowing one to obtain a full volume 3D data set of the entire LV.16 This 3D volume can then be cropped using any desired plane angulation. For example, a single apically acquired 3D data set potentially allows for display and analysis of all the standard apical 2D views (apical 2-, 3-, 4-, and 5-chamber views). This data set can also be used for analysis of shortaxis views from the apex to the base of the LV. In 2D echo, many geometric assumptions are made about LV shape.16 As mentioned earlier, many of the formulas, including the commonly used Simpson’s biplane method of discs, calculate LV volumes based on areas determined from only two imaging planes. According to a meta-analysis by Dorosz et al. Threedimensional echocardiography (3DE) provided more precise and accurate quantification of LV volumes and LVEF compared to two-dimensional echocardiography (2DE).22 3DE volumes were obtained by either a slice method or a mesh method. The slice method involved manual tracing of equally spaced individual long-or shortaxis slices at end-systole and end-diastole. The mesh

method required identification of 3–5 points at the apex and mitral annulus in the two- and four-chamber end-diastolic and end-systolic views. Software using automated borderdetection created a 3D endocardial shell of the LV from which a volume was calculated.22 They noted that 3DE also had less intraobserver and interobserver variability when compared with 2DE and under-represented true values approximately 50% less often. Dorosz et al. did find that compared to cardiac magnetic resonance imaging (CMR), 3DE underestimated LV volumes and there was significant variability in the LV volumes. This was more pronounced in patients with poor windows or large ventricles due to inability to fit the entire ventricle into the sector scan. They acknowledged that using CMR as a gold standard might be problematic due to errors in border detection and controversy surrounding the inclusion of basal LV planes.22 Three-Dimensional transthoracic echocardiography continues to be increasingly used in assessment of ventri cular volumes, ejection fractions, valvular disorders, cong enital heart disease, and evaluation of cardiac masses.23 Further discussion regarding the specific advantages of this modality can be found in other chapters in this book.

REFERENCES 1. Pereztol-Valdés O, Candell-Riera J, Santana-Boado C, et al. Correspondence between left ventricular 17 myocardial segments and coronary arteries. Eur Heart J. 2005; 26(24):2637–43. 2. Lang RM, Bierig M, Devereux RB, et al; Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recomm endations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 3. Wilson DJ, North N, Wilson RA. Comparison of Left Ventricular Ejection Fraction Calculation Methods. Echocardiography. 1998;15(8 Pt 1):709–12. 4. Feigenbaum, H. Role of M-mode technique in today’s echocardiography. J Am Soc Echocardiogr. 2010;23:240–57. 5. Quinones MA, Waggoner AD, Reduto LA, et al. A new, simplified and accurate method for determining ejection fraction with two-dimensional echocardiography. Circu lation. 1981;64(4):744–53. 6. Baran AO, Rogal GJ, Nanda NC. Ejection fraction deter mination without planimetry by two-dimensional echocardiography: a new method. J Am Coll Cardiol. 1983;1(6):1471–8.


7. Otto CM. Textbook of Clinical Echocardiography. Philadelphia: Saunders Elsevier; 2009. 8. Palmiero P, Maiello M, Nanda NC. Is echo-determined left ventricular geometry associated with ventricular filling and midwall shortening in hypertensive ventricular hypertrophy? Echocardiography. 2008;25(1):20–6. 9. Oh JK, Seward JB, Tajik AJ. The Echo Manual. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2006. 10. Gulati VK, Katz WE, Follansbee WP, et al. Mitral annular descent velocity by tissue Doppler echocardiography as an index of global left ventricular function. Am J Cardiol. 1996;77(11):979–84. 11. Biswas M, Sudhakar S, Nanda NC, et al. Two- and threedimensional speckle tracking echocardiography: clinical applications and future directions. Echocardiography. 2013;30(1):88–105. 12. Lax JA, Bermann AM, Cianciulli TF, et al. Estimation of the ejection fraction in patients with myocardial infar ction obtained from the combined index of systolic and diastolic left ventricular function: a new method. J Am Soc Echocardiogr. 2000;13(2):116–23. 13. Arnlöv J, Ingelsson E, Risérus U, et al. Myocardial perfor mance index, a Doppler-derived index of global left ventricular function, predicts congestive heart failure in elderly men. Eur Heart J. 2004;25(24):2220–5. 14. Karatzis EN, Giannakopoulou AT, Papadakis JE, et al. Myocardial performance index (Tei index): evaluating its application to myocardial infarction. Hellenic J Cardiol. 2009;50(1):60–5. 15. Miller AP, Nanda NC. Contrast echocardiography: new agents. Ultrasound Med Biol. 2004;30(4):425–34. 16. Mehta AM, Singh P, Nanda NC, et al. Left ventricular systolic function assessment by echo doppler examination.

1123

Proceedings of the Preconference CME Program of the XV Annual Conference of the Indian Academy of Echocardiography, February 11–14, 2010, Kochi, India. 17. Chantler PD, Lakatta EG, Najjar SS. Arterial-ventricular coupling: mechanistic insights into cardiovascular performance at rest and during exercise. J Appl Physiol. 2008;105(4):1342–51. 18. Fernandes VR, Polak JF, Cheng S, et al. Arterial stiffness is associated with regional ventricular systolic and diastolic dysfunction: the Multi-Ethnic Study of Atherosclerosis. Arterioscler Thromb Vasc Biol. 2008;28(1):194–201. 19. Saba PS, Ganau A, Devereux RB, Pini R, et al. Impact of arterial elastance as a measure of vascular load on left ventricular geometry in hypertension. J Hypertens. 1999; 17(7):1007–15. 20. Redfield MM, Jacobsen SJ, Borlaug BA, et al. Age- and gender-related ventricular-vascular stiffening: a comm unity-based study. Circulation. 2005;112(15): 2254–62. 21. Lam CS, Roger VL, Rodeheffer RJ, et al. Cardiac structure and ventricular-vascular function in persons with heart failure and preserved ejection fraction from Olmsted County, Minnesota. Circulation. 2007;115(15):1982–90. 22. Dorosz JL, Lezotte DC, Weitzenkamp DA, et al. Perfor mance of 3-dimensional echocardiography in measuring left ventricular volumes and ejection fraction: a syste matic review and meta-analysis. J Am Coll Cardiol. 2012;59(20):1799–808. 23. Nanda NC, Miller AP. Real time three-dimensional echocardiography: specific indications and incremental value over traditional echocardiography. J Cardiol. 2006; 48(6):291–303.

CHAPTER 52 How to Assess Diastolic Function Hisham Dokainish

Snapshot ¾¾ Integrating Echocardiographic Variables for Accurate

¾¾ Novel Imaging Techniques and Future Directions

Diagnosis of Diastolic Function

INTRODUCTION In patients presenting with dyspnea, accurate assessment of left ventricular (LV) systolic and diastolic function is of utmost importance to establish or exclude heart failure as a cause or component of dyspnea. Echocardiography with Doppler readily assesses LV diastolic function; advantages include that echocardiography is noninvasive, does not require radiation, is portable, rapid, readily available, and in competent hands, it can provide an accurate and comprehensive assessment of LV systolic and diastolic function. Correct assessment of LV diastolic function is relevant in patients with both depressed and preserved LV ejection fraction (EF < 50%, and ≥ 50%, respectively). Tissue Doppler (TD) imaging has been useful in demonstrating impaired LV relaxation in the setting of preserved left ventricular ejection fraction (LVEF), which, in the setting of increased cardiac volume, can result in elevated LV filling pressures and dyspnea due to diastolic heart failure. TD imaging is not always critical in patients with depressed LVEF, since such patients by definition have impaired LV relaxation, and thus significant increases in volume will result in increases in LV filling pressure due to impaired LV compliance. Thus, in depressed LVEF, transmitral flow velocities (E and A, and E/A) and deceleration time, pulmonary venous Doppler, left atrial volume, and pulmonary artery (PA) pressures suffice for the accurate assessment of LV filling pressures. Overall, diastolic assessment by echo Doppler can be readily achieved in

by using a comprehensive diastolic assessment—incor porating many 2-dimensional (2D), conventional, and tissue Doppler variables—as opposed to relying on any single, diastolic parameter, which can lead to errors.

Two-Dimensional Echocardiography: Left Ventricular Mass and Wall Motion, and Left Atrial Size According to current guidelines, the following three criteria are needed for the diagnosis of diastolic heart failure (DHF): clinical picture consistent with HF, demon stration of preserved LVEF, and demonstration of diastolic dysfunction.1 Clinically, diastolic dysfunction, secondary to impaired LV relaxation and increased LV stiffness, is usually demonstrated by echocardiography and Doppler.2–6 The best correlate of symptoms and survival in DHF is elevation of left atrial (or left ventricular filling) pressure, readily estimated using comprehensive echocardiography with Doppler.1,2 Demonstration of preserved LVEF is readily demonstrated with 2D echocardiography.7 It should be noted that DHF is a term used relatively intercha ngeably with “HF with preserved LVEF” and “HF with normal LVEF”. In DHF, LVEF is preserved ≥ 50%, yet left atrial pressures—synonymous with LV filling pressures in the absence of obstructive mitral valve (MV) disease— are elevated, causing increased pulmonary venous

Chapter 52: How to Assess Diastolic Function

1125

Fig. 52.1: Left ventricular hypertrophy in a patient with diastolic dysfunction. Chronic hypertension is a common scenario for the development of diastolic dysfunction, and the hypertrophied left ventricle (LV) develops impaired relaxation, and in the right loading conditions, can result in elevated left atrial (LA) pressure. This patient had concentric LV hypertrophy (LV mass index = 119 g/m2).

Fig. 52.2: Presence of left atrial dilation in the patient with left ventricular diastolic dysfunction. The same patient as in Figure 52.1 has severely dilated left atrium (LA) from chronic elevation in LA pressures in the setting of left ventricular hypertrophy from chronic hypertension. Note that the LA does not appear significantly dilated by anteroposterior diameter in Figure. 52.1; this is the reason current guidelines recommend the measurement of LA volume in the apical views. This patient had severe LA enlargement, with an unindexed LA volume of 137 mL and an indexed volume of 72 mL/m2.

pressures and dyspnea at rest or during exertion.1–6 In order for left atrium (LA) pressures to be elevated in the absence of significantly depressed LVEF, LV relaxation and compliance generally are depressed, most often occurring in hypertensive or ischemic heart disease.2–5 Two-dimensional echocardiography, therefore, identifies LV abnormalities that create the substrate for LV diastolic dysfunction: LV hypertrophy and LV wall motion abnormalities. Increased LV mass (≥ 90 g/m2 for women and ≥ 115 g/m2 for men; i.e. LV hypertrophy) is common in patients with DHF5 (Figs 52.1 and 52.2). Previous studies have correlated increasing degrees of LV mass with increasing LV diastolic dysfunction and filling pressures.8 In addition, since LVEF can be preserved even in the presence of significant coronary artery disease, LV wall motion abnormalities create the substrate for significant LV diastolic dysfunction even in the patient with preserved LVEF who may have a diagnosis of DHF. Therefore, accurate identification of LV wall motion abnormalities is of great importance in the assessment of the patient with potential diastolic dysfunction. Since LA pressures are elevated in patients with significant diastolic dysfunction in the presence of increased preload, and

since the LA cannot adequately empty in to the LV during diastole in this hemodynamic scenario, LA enlargement (≥ 30 mL/m2) is usually seen.5 Increasing LA size correlates with increasing LV filling pressures and worse outcome in patients with diastolic HF.9 In addition, LA size has been called the barometer of LV diastolic dysfunction or LV filling pressures, although certainly other entities, such as atrial fibrillation or chronic hypertension, can result in LA enlargement in the absence of significant elevation of LA pressure.6 It has therefore been said that LA volume has a better negative—as opposed to positive—predictive value for significant diastolic dysfunction and heart failure; that is, a normal or small LA largely excludes significantly elevated LA pressure, while a large LA volume may occur in the absence of significant LA dilation.10 Studies have also shown that LA volume is a much better measurement of LA enlargement than a simple anteroposterior diameter, and therefore is the recommended way to measure LA size by echocardiography.6 It is also important to integrate 2D echocardiographic variables in the assessment of diastolic function; for instance, in cases of ischemic or infiltrative heart disease, significant LV hypertrophy may be absent, yet LA volumes are often enlarged.5

1126


Fig. 52.3: Transmitral diastolic inflow for the assessment of left ventricular filling pressures. (Left panel): mitral inflow in the normal heart shows early transmitral diastolic inflow greater than late transmitral diastolic inflow (E > A) due to rapid diastolic function and normal left ventricular filling pressures (LVFP); (Middle panel): in the patient with impaired LV relaxation but normal LVFP, E is lower than A, as the LV depends more on atrial kick for LV filling; this is also termed Grade I diastolic dysfunction (DD); (Right panel): in the patient with pseudonormal filling pattern, there is impaired LV relaxation but E > A, and is caused by elevated LA pressures; this is also termed Grade I diastolic dysfunction (DD). Valsalva maneuver and tissue Doppler imaging can help distinguish normal from pseudonormal filling (see Fig. 52.5 and text for details).

Fig. 52.4: Restrictive transmitral filling pattern. When left ventricular (LV) filling pressures are severely elevated due to increased LV diastolic stiffness, early transmitral diastolic flow (E) has a high velocity because there is an initial high gradient between very elevated left atrial (LA) pressure and LV diastolic pressure. However, due to elevated resting LV diastolic pressures, the LA and LV pressures rapidly equilibrate, resulting in a rapid deceleration time (DT) of transmitral E. In general, in a patient with cardiac disease, restrictive filling occurs when E/A > 2 and DT < 150 milliseconds. A = late transmitral diastolic velocity.

Identification of Diastolic Dysfunction and Demonstration of Elevated Left Ventricular Filling Pressures

this pattern is termed “pseudonormalization.” In markedly elevated LV filling pressure in which LV stiffness is high, the MV is forced open early due to high LA pressure, but there is rapid equilibration with the high resting LV diastolic pressure resulting in a rapid deceleration time of E. This pattern is termed “restrictive filling” (Fig. 52.4).3–5 The grades of diastolic function, as assessed using comprehensive echo Doppler examination, are shown in Figure 52.5.

Transmitral Doppler Pulsed Doppler interrogation of mitral valve diastolic flow (“mitral inflow pattern”) is critical for the assessment of LV filling pressures. Early mitral filling depends on intrinsic LV relaxation, and the difference between LA and LV early (or “opening”) diastolic pressure.5 In a healthy, young heart with normal, rapid diastolic suction, the LV literally “sucks” blood into the LV, resulting in rapid LA emptying. In this scenario, there is a relatively tall E-wave and a shorter A (late diastolic or “atrial contraction” wave; Fig. 52.3). In an LV with impaired relaxation but normal LV filling pressures, there is no rapid LV diastolic suction, thus LA emptying is more gradual and results in a relatively low velocity E-wave; LA emptying is therefore dependent on LA contraction and results in a relatively high amplitude A-wave. In the setting of impaired LV relaxation and mildly elevated LA pressure, high LA pressure that “drives” open the MV, resulting in a large E-wave and smaller A-wave;

Valsalva Maneuver In the Valsalva maneuver in which the patient forces expiration against a closed glottis, there is increased intrathoracic pressure that results in decrease in right heart filling which by definition, results in decreased LV filling (decreased preload). Since a pseudonormal filling pattern exists in the setting of elevated LA pressure in the presence of impaired LV relaxation, this decrease in preload lowers LA pressure, which then “unmasks” the underlying impaired relaxation pattern (i.e. E > A in the setting of impaired relaxation and with Valsalva maneuver changes the transmitral pattern to E < A; Fig. 52.5). On the


Fig. 52.5: Grades of left ventricular diastolic dysfunction. Left ventricular (LV) diastolic function ranges from normal (Grade 0) to impaired relaxation (Grade I), to pseudonormal (Grade II), to restrictive (Grade III), and irreversibly restrictive (Grade IV). LV relaxation and left atrial pressures (LAp) increase from Grades 0 to IV, as does LA volume. Mitral valve inflow (MVI), tissue Doppler imaging, Valsalva maneuver, flow propagation velocity (Vp), and pulmonary venous flow are all helpful in distinguishing grades of LV diastolic function and should be used together for an integrated approach to the assessment of diastolic function as recommended in current guidelines. (Adapted from ref. 31).

other hand, in the setting of normal diastolic function, the decrease in preload resulting from the Valsalva maneuver preserves the E > A pattern, without changing it to E < A. Therefore, one of the main uses of the Valsalva maneuver— similar to tissue Doppler e'—is to help distinguish normal from pseudonormal filling pattern. In the presence of a restrictive filling pattern, the Valsalva maneuver will decrease preload and therefore help distinguish irreversible restrictive filling pattern (in which E >> A will not change) from reversible restrictive filling, where decreased preload changes the restrictive filling pattern to either pseudonormal (E > A) or impaired relaxation pattern (E < A), since the increased intrathoracic pressure resulting from Valsalva decreases LA pressure.

Tissue Doppler Imaging The best estimate of LV relaxation, which is relatively nonload dependent in patients with cardiac disease, is tissue Doppler early diastolic mitral annular velocity (e');11–14 the slower the LV relaxation, the lower the e' velocity. The resulting E/e' ratio, has been validated as a reasonably reliable non-invasive indicator of LV filling

1127

pressure in patients with preserved or depressed LVEF (Figs 52.6A to D).11–14 It should be mentioned that one study, performed in the intensive care unit in patients in decompensated heart failure, questioned the correlation of /e' and LV filling pressures.15 In patients with normal hearts, E/e' does not accurately predict LV filling pressure due to correlation of e' with LV filling pressures in such subjects, as opposed to lack of such a correlation in patients with cardiac disease.16 The E/e' ratio has since been demon strated to be useful in estimating LV filling pressures in hypertrophic cardiomyopathy,17 sinus tachycardia,18 atrial fibrillation,19 and postcardiac transplantation.20 The E/A ratio, mitral deceleration time, and E/e' ratio have all been shown to be useful echocardiographic indicators of LV diastolic dysfunction, and more particularly, of elevated LV filling pressures.5 These variables have also been shown to be markers of outcome in patients with HF.9,21

Flow Propagation Velocity In the apical four-chamber view, color Doppler imaging can be used and then M-mode applied to semi-quantitate blood flow across the mitral valve to the LV apex (Fig. 52.7). In this way, the early diastolic filling wave by color M-mode, which appears in red color as blood flow from the mitral valve level to the LV apex can be identified. The slope of this early diastolic color M-mode wave (Vp) is rapid (vertical) in patients with normal diastolic function due to rapid diastolic suction in which blood quickly flows from MV to LV apex. However, in the presence of increasingly impaired relaxation, this slope become flatter and flatter, reflecting increasingly impaired LV relaxation. A ratio, E/Vp, similar to E/e, has therefore been developed and validated, and correlates to mean LA pressure.22 An E/Vp > 15 reasonably correlates with PCWP > 15 mm Hg, although there are many hemodynamic, rhythmic, and myocardial motion variables that can impact this relationship. Furthermore, some studies have shown that, in comparison to invasive measurement of LV filling pressures, E/e' appears more accurate than E/Vp.23

Pulmonary Venous Flow Pulmonary venous flow is also of great importance in the assessment of LV diastolic function. In the normal heart with rapid ventricular suction, the diastolic pulmonary venous wave is augmented due to rapid flow through the pulmonary veins into the LA, through the mitral valve, and

1128


A

B

C

D

Figs 52.6A to D: Tissue Doppler imaging for the assessment of left ventricular (LV) diastolic function. Figure A shows an apical fourchamber view with moderate to severe dilation of the left atrium (LA) with an LA volume index of 39 mL/m2; Figure B demonstrates elevated early transmitral diastolic velocity (E) = 117 cm/s; Figure C shows very depressed mitral lateral annular early diastolic relaxation velocity (e') = 3.5 cm/s; Figure D shows very depressed septal tissue Doppler (TD) early diastolic velocity (e') = 2.5 cm/s. Therefore, E/e' septal = 47, and E/e' lateral = 33, indicating severely impaired LV relaxation with elevated LV filling pressures. (PCWP: Pulmonary capillary wedge pressure).

into the LV. Therefore, in the completely normal heart, the dominant PV diastolic wave corresponds to the dominant transmitral E-wave and is a sign of normal LV lussotropic function; the completely normal heart therefore has PV S < D. However, when LV relaxation becomes impaired, PV flow during LV diastole becomes truncated, and therefore most filling occurs during LV systole, resulting in S > D, which corroborates to transmitral E < A (Grade I diastolic dysfunction; Fig. 52.8).24 When LA pressure becomes elevated, PV flow during LV systole decreases, as LA pressure in the setting of a closed MV prevents normal PV flow, and PV flow becomes higher in diastolic when the mitral valve opens, relieving elevated LA

pressure; this results in PV S < D, corresponding to E > A (Grade II diastolic dysfunction). Therefore, PV flow is subject to pseudonormalization in the same way as transmitral flow. In restrictive filling, the PV pseudonormal pattern becomes more exaggerated, with S << D, with a rapid deceleration time of D. While the PV S/D ratio reflects mean LA pressure, the PV atrial reversal wave reflects LV end-diastolic pressure, as, if the LA contracts against the high diastolic pressure in the LV, blood will preferentially flow backward into the PV, as opposed to transmitrally into the LV. Therefore, PV Ar wave is higher and longer than transmitral A, rendering PV Ar-A a measure of LV enddiastolic pressure.


Fig. 52.7: Color Doppler flow propagation velocity (Vp) in the assessment of left ventricular diastolic function. Placing the color Doppler sample volume from the mitral annular level to the left ventricular (LV) apex, the more rapid the LV relaxation, the faster blood travels from the mitral annular level to the LV apex, and hence the more vertical the color Doppler mitral inflow M-mode and the more rapid the Vp slope (left panel). On the other hand, the more impaired the LV relaxation, the slower it takes for blood to go from the mitral annular to the LV apex, hence a “flatter” Vp slope (right panel).

Pulmonary Artery Pressure In the setting of elevated LA pressure, this pressure is transmitted back into the pulmonary veins and across the pulmonary venous-capillary bed into the pulmonary arterioles and into the pulmonary arteries; therefore, pulmonary arterial hypertension (PAH) can result.25 In this way, PA pressure estimated by addition of an estimate of RA pressure (by assessing IVC size and response to respiration) is a good surrogate marker of significant, and often chronic, LA pressure elevation (Figs 52.9A and B). As recommended by guidelines, PASP > 35 mm Hg often accompanies advanced or significant LV diastolic dysfunction with elevated LA pressures.5 However, as with LA volume, the presence of significant PAH does not necessarily mean significant diastolic dysfunction, as significant elevations in pulmonary vascular resistance (PVR) due to intrinsic lung disease must first be excluded. Likewise, normal PASP can be helpful in excluding significant and long-standing LA pressure elevation, provided a complete TR jet is obtained with correct Doppler sample volume angulation in respect of the direction of TR, and with correct RA pressure estimation. PA end-diastolic pressure, which in the absence of significant elevations in PVR can be a good estimate of

1129

Fig. 52.8: Pulmonary venous Doppler velocities in the assessment of left atrial pressures. In normal heart, systolic pulmonary venous (PV) flow (S) is lower than diastolic PV flow (D), as rapid left ventricular (LV) suction during diastole results in elevated PV D velocities; thus, PV S < D. In patients with impaired LV relaxation and elevated LA pressure, when the mitral valve (MV) is closed in ventricular systole, the elevated LA pressure prevents PV S flow, and therefore most flow occurs when the MV opens, resulting in S < D. Therefore, as with mitral inflow velocities, PV velocities are also prone to pseudonormal filling. In this example, there is impaired LV relaxation due to cardiomyopathy, but LA pressure is not elevated; thus, when the MV is closed (LV systole), there is unimpeded flow through the PV, and hence S > D.

mean LA pressure, can be estimated from the pulmonary regurgitation diastolic wave, with RA pressure then added to it as is done with PASP.26

Assessment of Diastolic Function in Nonsinus Rhythm and Other Special Situations One commonly encountered scenario where it can be challenging to accurately assess LV diastolic function by echocardiography is in atrial fibrillation. Owing to elevated heart rate, irregular R–R intervals, and loss of atrial contraction, echo Doppler assessment can be difficult. However, mitral DT < 150 milliseconds, lack of variation in E-wave velocity despite varying R–R intervals (as there remains an elevated opening gradient between the LA and LV at mitral opening—early diastolic filling E-wave—despite longer diastolic filling periods when the LA pressure should decrease), IVRT < 65 milliseconds, elevation of E/e' (>11), and the presence of pulmonary hypertension in the absence of lung disease, are all clues to the presence of elevated LA pressure in the setting of AF.5,27,28 The E/e' ratio can also be used in patients with AF,

1130


A

B

Figs 52.9A and B: Pulmonary artery systolic pressure in the assessment of left ventricular diastolic function. In patients with significant left ventricular (LV) diastolic dysfunction with chronically elevated LV filling pressures, back pressure through the left atrium (LA), into the pulmonary veins, and across the pulmonary venous capillary bed into the pulmonary arterioles and pulmonary arteries (PA), results in elevation of PA pressure. Thus, PA systolic pressure elevation, in the absence of significant intrinsic lung disease and resultant elevated pulmonary vascular resistance (PVR) is a reasonable correlate of elevated LA pressures. PA systolic pressure can be estimated by Doppler using the tricuspid regurgitation peak systolic velocity and adding to it an estimate of right atrial (RA) pressure. This image shows a TR velocity of 3.64 m/s, equivalent to a TR systolic pressure of 53 mm Hg, which indicates at least moderate PA hypertension in a patient with chronically elevated LA pressure due to ischemic cardiomyopathy and diastolic dysfunction. (RV: Right ventricular).

Fig. 52.10: An integrated approach to the assessment of left ventricular diastolic function: normal LV ejection fraction. As recommended in the current guidelines, use of multiple echo Doppler parameters results in a more accurate assessment of left ventricular (LV) diastolic function than using any single echo Doppler parameter in isolation. In the patient with normal LV ejection fraction (EF), it is reasonable to start with early transmitral diastolic velocity/tissue Doppler early diastolic velocity (E/e'), as it can be difficult to discern whether a patient with preserved LVEF has impaired or normal LV relaxation. Following E/e', other echo Doppler variables are added to result in an accurate assessment of LV diastolic function (from ref. 5).

although with somewhat lower accuracy than in patients in sinus rhythm, for the estimation of LV filling pressures, as long as greater than five cardiac cycles are used and averaged (which holds for any Doppler parameter in AF).19 In patients who are in supraventricular tachycardia, atrial flutter, paced rhythm, or heart block, LV diastolic assessment can be very difficult, although the presence of both significant LA enlargement and pulmonary hypertension in the absence of lung disease can be an important clue to elevated LA pressures in these scenarios. Another unclear scenario is the effect of significant mitral regurgitation (MR) on e' and the E/e' ratio in estimating LV filling pressures. It has been shown that in patients with secondary MR (due to LV disease), E/e' accurately predicted PCWP; however, in patients with primary MR (due to a primary mitral valve abnormality), E/e' was not reliably predictive of PCWP.29

INTEGRATING ECHOCARDIOGRAPHIC VARIABLES FOR ACCURATE DIAGNOSIS OF DIASTOLIC FUNCTION The use of a single diastolic variable (such as E/e' or LA volume in isolation) can lead to significant errors in the assessment of LV diastolic function.5 It is therefore


1131

Fig. 52.11: An integrated approach to the assessment of left ventricular diastolic function: depressed ejection fraction. As recommended in the current guidelines, use of multiple echo Doppler parameters results in a more accurate assessment of left ventricular (LV) diastolic function than using any single echo Doppler parameter in isolation. In the patient with depressed LV ejection fraction (EF), it is reasonable to start with early and late transmitral diastolic inflow velocities and deceleration time (E, A and DT, respectively), as it can assumed that patients with depressed LVEF (< 50%) have, by definition, impaired LV relaxation. Following transmitral diastolic flow, other echo Doppler variables are added to result in an accurate assessment of LV diastolic function (from ref. 5).

Fig. 52.12: Longitudinal strain by speckle echocardiography in the demonstration of systolic myocardial dysfunction in a patient with normal left ventricular ejection fraction. This elderly patient presented with dyspnea and underwent echocardiography with speckle imaging. Left ventricular ejection fraction (LVEF) was calculated at 55%, while global longitudinal peak strain (GLPS Avg) was −11.1, consistent with significantly decreased myocardial systolic function (normal longitudinal systolic strain less than −16%). GLPS Avg was obtained by averaging GLPS in the apical long-axis (LAX), four-chamber (A4C), and two-chamber (A2C) views. There are substantial data using tissue Doppler and speckle imaging demonstrating significant systolic abnormalities in patients with diastolic dysfunction and heart failure despite normal LVEF. This patient was subsequently diagnosed with diastolic heart failure and single vessel coronary artery disease.

of great importance to integrate several variables—2D, conventional, and tissue Doppler—in order to arrive at a correct diastolic assessment. Indeed, current guidelines recommend an integrated approach of many diastolic variables (Figs 52.10 to 52.12), and data have shown that additional echocardiographic variables, when added to E/e' can result in more accurate diastolic determination, compared to invasively measured LV filling pressures, than E/e' alone.30 Not infrequently, echo Doppler parameters appear to conflict: for instance, in a patient with normal LVEF, E/e' = 13, but LA volume is not enlarged, E < A, and there are normal pulmonary pressures by Doppler. In such cases, the E/e' ratio should likely be dropped, since all other variables point toward normal LV filling pressures. Therefore, as a rule, multiple echo Doppler parameters of LV diastolic function should be assessed in every patient,31 and the conclusion to which most parameters point should be the overall diastolic assessment, with “outlying” parameters discarded. In most cases of conflicting echo Doppler diastolic parameters, a cogent conclusion can be

reached, although in some cases, the diastolic assessment may remain equivocal. Above all, no single diastolic parameter should be used in isolation to arrive at a diastolic conclusion in a given patient.5

NOVEL IMAGING TECHNIQUES AND FUTURE DIRECTIONS Non-Doppler-based 2D imaging (“speckle echocardi ography”) tracks signature grayscale characteristic of points in the LV myocardium, thus providing information on displacement, velocity, deformation, and deformation rate (strain and strain rate, respectively), independent of angulation and cardiac translational motion.32 Such variables have provided detailed information on myocardial mechanics in hypertensive heart disease, hypertrophic cardiomyopathy, diastolic and systolic LV failure, as well as in cases of pulmonary hypertension.33–35 Currently, such speckle-based measures are being studied to assess their role in identifying patient outcome in

1132


various heart failure states. One of the most attractive features of speckle tracking is that it can demonstrate the presence of systolic abnormalities, especially regional ones, in the presence of preserved LVEF in patients with cardiac disease (see Fig. 52.12).36 Speckle tracking can also demonstrate systolic and diastolic abnormalities in multiple vectors (longitudinal, radial, circumferential, and rotational) as characteristic myocardial markers are tracked throughout the cardiac cycle and in space as the heart translates in the thoracic cavity. In particular, patients with diastolic dysfunction and DHF have been shown to have preserved LV twist (systole) and untwist (diastole) but impaired longitudinal strain, whereas patients with HF with depressed EF have impaired twist/untwist as well as depressed longitudinal and circumferential strain.30–34

SUMMARY Comprehensive echocardiography with 2D imaging, and spectral and color Doppler—as well as newer techniques like speckle strain echocardiography—provide a complete assessment of cardiac diastolic function. This assessment, which includes LV mass and regional wall motion assessment, LA volume, transmitral, pulmonary venous, and tissue Doppler as well as estimation of PA systolic and diastolic pressures, can provide accurate assessments of diastolic function in the majority of patients. It is important to note that, as recommended in current guidelines, use of any single echo Doppler diastolic variable (e.g. only E/e') in isolation, can lead to errors. Therefore, it is of utmost importance that a comprehensive assessment of LV diastolic function include integration of all available 2D and Doppler, and tissue Doppler variables to arrive at the most accurate diastolic assessment.

REFERENCES 1. Paulus WJ, Tschöpe C, Sanderson JE, et al. How to diagnose diastolic heart failure: a consensus statement on the diag nosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology. Eur Heart J. 2007;28(20):2539–50. 2. Zile MR, Baicu CF, Gaasch WH. Diastolic heart failure– abnormalities in active relaxation and passive stiffness of the left ventricle. N Engl J Med. 2004;350(19):1953–9. 3. Oh JK, Hatle L, Tajik AJ, et al. Diastolic heart failure can be diagnosed by comprehensive two-dimensional and Doppler echocardiography. J Am Coll Cardiol. 2006;47(3):500–6.

4. Lester SJ, Tajik AJ, Nishimura RA, et al. Unlocking the mysteries of diastolic function: deciphering the Rosetta Stone 10 years later. J Am Coll Cardiol. 2008;51(7):679–89. 5. Nagueh SF, Appleton CP, Gillebert TC, et al. Recomm endations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009;22(2):107–33. 6. Abhayaratna WP, Seward JB, Appleton CP, et al. Left atrial size: physiologic determinants and clinical applications. J Am Coll Cardiol. 2006;47(12):2357–63. 7. Lang RM, Bierig M, Devereaux RB, et al. Recommendations for chamber quantification. J Am Soc Echocardiogr 2005; 18:1440–63. 8. Dokainish H, Sengupta R, Pillai M, et al. Assessment of left ventricular systolic function using echocardiography in patients with preserved ejection fraction and elevated diastolic pressures. Am J Cardiol. 2008;101(12):1766–71. 9. Dokainish H, Zoghbi WA, Lakkis NM, et al. Incremental predictive power of B-type natriuretic peptide and tissue Doppler echocardiography in the prognosis of patients with congestive heart failure. J Am Coll Cardiol. 2005;45(8):1223–6. 10. Dokainish H, Zoghbi WA, Lakkis NM, et al. Optimal noninvasive assessment of left ventricular filling pressures: a comparison of tissue Doppler echocardiography and B-type natriuretic peptide in patients with pulmonary artery catheters. Circulation. 2004;109(20):2432–9. 11. Sohn DW, Chai IH, Lee DJ, et al. Assessment of mitral annulus velocity by Doppler tissue imaging in the evaluation of left ventricular diastolic function. J Am Coll Cardiol. 1997;30(2):474–80. 12. Nagueh SF, Middleton KJ, Kopelen HA, et al. Doppler tissue imaging: a noninvasive technique for evaluation of left ventricular relaxation and estimation of filling pressures. J Am Coll Cardiol. 1997;30(6):1527–33. 13. Ommen SR, Nishimura RA, Appleton CP, et al. Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: A comparative simultaneous Doppler-catheterization study. Circulation. 2000;102(15):1788–94. 14. Kasner M, Westermann D, Steendijk P, et al. Utility of Doppler echocardiography and tissue Doppler imaging in the estimation of diastolic function in heart failure with normal ejection fraction: a comparative Dopplerconductance catheterization study. Circulation. 2007; 116(6):637–47. 15. Mullens W, Borowski AG, Curtin RJ, et al. Tissue Doppler imaging in the estimation of intracardiac filling pressure in decompensated patients with advanced systolic heart failure. Circulation. 2009;119(1):62–70. 16. Firstenberg MS, Levine BD, Garcia MJ, et al. Relationship of echocardiographic indices to pulmonary capillary wedge pressures in healthy volunteers. J Am Coll Cardiol. 2000;36(5):1664–9.


17. Nagueh SF, Lakkis NM, Middleton KJ, et al. Doppler estimation of left ventricular filling pressures in patients with hypertrophic cardiomyopathy. Circulation. 1999;99(2): 254–61. 18. Nagueh SF, Mikati I, Kopelen HA, et al. Doppler estimation of left ventricular filling pressure in sinus tachycardia. A new application of tissue Doppler imaging. Circulation. 1998;98(16):1644–50. 19. Sohn DW, Song JM, Zo JH, et al. Mitral annulus velocity in the evaluation of left ventricular diastolic function in atrial fibrillation. J Am Soc Echocardiogr. 1999;12(11):927–31. 20. Sundereswaran L, Nagueh SF, Vardan S, et al. Estimation of left and right ventricular filling pressures after heart transplantation by tissue Doppler imaging. Am J Cardiol. 1998;82(3):352–7. 21. Yu CM, Sanderson JE, Marwick TH, et al. Tissue Doppler imaging a new prognosticator for cardiovascular diseases. J Am Coll Cardiol. 2007;49(19):1903–14. 22. Garcia MJ, Ares MA, Asher C, et al. An index of early left ventricular filling that combined with pulsed Doppler peak E velocity may estimate capillary wedge pressure. J Am Coll Cardiol. 1997;29(2):448–54. 23. Rivas-Gotz C, Manolios M, Thohan V, et al. Impact of left ventricular ejection fraction on estimation of left ventri cular filling pressures using tissue Doppler and flow propagation velocity. Am J Cardiol. 2003;91(6):780–4. 24. Appleton CP, Galloway JM, Gonzalez MS, et al. Estimation of left ventricular filling pressures using two-dimensional and Doppler echocardiography in adult patients with cardiac disease. Additional value of analyzing left atrial size, left atrial ejection fraction and the difference in duration of pulmonary venous and mitral flow velocity at atrial contraction. J Am Coll Cardiol. 1993;22(7):1972–82. 25. Neuman Y, Kotliroff A, Bental T, et al. Pulmonary artery pressure and diastolic dysfunction in normal left ventricular systolic function. Int J Cardiol. 2008;127(2):174–8. 26. Paraskevaidis IA, Tsiapras DP, Karavolias GK, et al. Dopplerderived left ventricular end-diastolic pressure prediction model using the combined analysis of mitral and pulmonary A waves in patients with coronary artery disease and preserved left ventricular systolic function. Am J Cardiol. 2002;90(7):720–4.

1133

27. Nagueh SF, Kopelen HA, Quiñones MA. Assessment of left ventricular filling pressures by Doppler in the presence of atrial fibrillation. Circulation. 1996;94(9):2138–45. 28. Al-Omari MA, Finstuen J, Appleton CP, et al. Echocardi ographic assessment of left ventricular diastolic function and filling pressure in atrial fibrillation. Am J Cardiol. 2008;101(12):1759–65. 29. Bruch C, Stypmann J, Gradaus R, et al. Usefulness of tissue Doppler imaging for estimation of filling pressures in patients with primary or secondary pure mitral regurgi tation. Am J Cardiol. 2004;93(3):324–8. 30. Dokainish H, Nguyen JS, Sengupta R, et al. Do additional echocardiographic variables increase the accuracy of E/e’ for predicting left ventricular filling pressure in normal ejection fraction? An echocardiographic and invasive hemodynamic study. J Am Soc Echocardiogr. 2010;23(2): 156–61. 31 Ommen SR, Nishimura RA. A clinical approach to the assessment of left ventricular diastolic function by Doppler echocardiography: update 2003. Heart 2003;89 (Suppl 3):18–23. 32. Perk G, Tunick PA, Kronzon I. Non-Doppler two-dimen sional strain imaging by echocardiography—from tech nical considerations to clinical applications. J Am Soc Echocardiogr. 2007;20(3):234–43. 33. Wang J, Khoury DS, Yue Y, et al. Preserved left ventricular twist and circumferential deformation, but depressed longitudinal and radial deformation in patients with diastolic heart failure. Eur Heart J. 2008;29(10):1283–9. 34. Wang J, Khoury DS, Yue Y, et al. Left ventricular untwisting rate by speckle tracking echocardiography. Circulation. 2007;116(22):2580–6. 35. Dokainish H, Sengupta R, Pillai M, et al. Usefulness of new diastolic strain and strain rate indexes for the estimation of left ventricular filling pressure. Am J Cardiol. 2008;101(10): 1504–9. 36. Nguyen JS, Lakkis NM, Bobek J, et al. Systolic and diastolic myocardial mechanics in patients with cardiac disease and preserved ejection fraction: impact of left ventricular filling pressure. J Am Soc Echocardiogr. 2010;23(12):1273–80.

CHAPTER 53 Evaluation of the Right Ventricle Vincent L Sorrell, Steve W Leung, Brandon Fornwalt

Snapshot ¾¾ General Overview ¾¾ Right Ventricle Morphology ¾¾ Echocardiography ¾¾ M-Mode Echocardiography ¾¾ Two-Dimensional Echocardiography ¾¾ Doppler Echocardiography

GENERAL OVERVIEW The assessment of the right ventricle (RV) is valuable in many patients with heart disease. In patients with either RV volume overload (e.g. repaired tetralogy of Fallot [TOF], atrial septal defect [ASD], anomalous pulmonary venous return, tricuspid regurgitation [TR] from any cause) or RV pressure overload (e.g. pulmonary hypertension from any cause, pulmonary stenosis), management decisions increasingly rely on evaluation of the RV size and function. Their trends during serial follow-up examinations predict heart failure, arrhythmias, and death and must be reliable.1 The noninvasive diagnostic evaluation of RV size and function in normal and pathological conditions is daunting due to its complex shape, nonsymmetrical regional contraction pattern, and the lack of published literature on normal reference values. Most physicians practicing echocardiography are comfortable analyzing the relatively simple circular geometry of the left ventricle (LV), but the RV is shaped like a “pyramidal banana.” The inflow and outflow portions are separated. The normal RV shape varies depending on orientation: sagittal view (echo

¾¾ Two-Dimensional Strain (Speckle Tracking) ¾¾ Three-Dimensional Echocardiography ¾¾ Transesophageal Echocardiography ¾¾ Hemodynamics ¾¾ Other Imaging Modalities

short axis) is triangular (curved); axial view (echo long axis) is crescent-shaped; and coronal view (not possible with two-dimensional [2D] echo) is most similar to a teapot (Fig. 53.1). The RV myocardial wall is highly trabeculated and barely 3 mm thin. In summary, there is no convenient geometric model that accurately approximates the normal or the diseased RV shape. In addition to the variable shape, the regional contr action pattern is also unique to the RV. The normal RV apex is virtually immobile and tethered to the LV apex, and therefore is dominated by the shape and function of the adjacent left ventricular apex. The global RV systolic function is strongly influenced by the normally concave interventricular septum and ventricular interdependence. Acute and chronic pathological pressure and volume overload will greatly impact global and regional RV performance. Finally, global RV performance is influenced by volume shifts that occur with normal respiration. During inspiration, venous return increases, causing an increased RV preload, with a slight but detectable increase in RV stroke volume. Therefore, when quantifying RV volume

Chapter 53: Evaluation of the Right Ventricle

Fig. 53.1: Three dimensional display of complex RV geometry. Left column demonstrates a 3D echo and the middle column is a 3D cardiac MR (CMR) exam of a normal patient. Top row: ”cardiac-aligned” short axis; Middle row: sagittal orientation; Bottom row: oblique coronal or frontal plane. The two images in the right column represent conventional long axis orientation (four-chamber view) of CMR (top) and 2D echo (bottom).

and function with echo, one should consider whether data were acquired during inspiration, expiration, or apnea (preferred). These features unique to the RV result in highly variable interpretations despite highly trained experts in echocardiography. Most clinical studies simply use the “eye-ball” qualitative assessment rather than resorting to quantitative, or even semiquantitative, estimates of RV size and function. Unfortunately, compared with the reference standard (cardiac magnetic resonance imaging [CMR]), the ability to accurately detect severely dilated RV size or moderate to severe RV dysfunction is low and the interobserver variability is extremely poor.2 This chapter describes the unique characteristics of the RV and offers a comprehensive, quantitative echocar diographic (and multimodal imaging) approach to the investigation of the normal and pathological RV.

RIGHT VENTRICLE MORPHOLOGY The RV can be considered to comprise three individual and separate components—the apex, the inflow, and the outflow (Fig. 53.2). Although there is significant individual normal variability, the anterior and posterior trabecular muscles, and the smaller medial papillary muscle are within the RV inflow region and connected to the tricuspid valve leaflets via the chordae tendineae. The moderator

1135

Fig. 53.2: Left Image: Three-dimensional echocardiography (3DE) volume rendered display with color-coded regions representing the triangle of dysplasia. The arrows in the inflow and outflow regions reflect the myofiber alignment and direction of contraction. The larger center arrow represents the ventricular septal motion into the cavity (toward the left ventricle). Right Image: Posterioranterior orientation of a cadaveric cast from a normal RV. Note the complex nongeometric shape as well as the extensive trabeculation throughout the RV myocardium, although slightly less obvious in the so-called “smooth” inflow region. Courtesy: Special thanks to Frank Marcus for the image.

band is a variably prominent muscular extension that houses the electrical apparatus of the right bundle of His as it travels from the ventricular septum to the anterolateral region of the RV. These RV regions are commonly the initial sites involved in pathology and have been termed the “triangle of dysplasia.”3 These anatomical regions develop separ ately and at distinct embryological time points and are consequently independently subjected to congenital malformations. Each anatomical region has been demonstrated to have unique responses to pathology as well as pharmacological interventions. The right ventri cular outflow tract (RVOT) has been demonstrated to be more reactive than the RV inflow tract to inotropic stimulation.4 This may be important when evaluating RV response to treatment with inotropic drugs. The global RV systolic function is determined by the following individual RV contraction patterns: (a) move ment of the basal free wall toward the apex (the “bellows effect”); (b) the contraction of the RVOT; and (c) the contribution of the LV (tethering) at the interventricular insertion sites. The influence of the ventricular septum (interventricular dependence) is illustrated by impairment of RV function due to the adjacent diseased LV, but not

1136


muscle bundles, because these may alter the symmetric contraction of the RV free wall.7,8 Moreover, different regions of the RV contract at different times in healthy volunteers with the inflow region reaching peak contraction first, followed by the outflow region and lastly the apex approximately 100 ms later.9 Although severe focal regional wall motion abnormalities may exist in diseases such as arrhythmogenic RV dysplasia/cardiomyopathy (Movie clip 53.3B), these more subtle, normal regional variations need to be recognized as normal or else they may inadvertently lead to misinterpretation with important downstream consequences.

ECHOCARDIOGRAPHY Fig. 53.3: Cardiac magnetic resonance imaging midventricular steady-state free precession (SSFP) images of a normal (control; top) and pathological (tetralogy; bottom) heart demonstrating the variation in time–volume (TV) curves (right side). Note the dilated right ventricle (RV) and delay in contraction of the surgically repaired tetralogy of Fallot patient (tetralogy). Right ventricular endocardial tracing and TV curves, green; left ventricular endocardial tracing and TV curves, yellow.

necessarily due to a specific myopathic process of the RV myocardium.5 Given a normal pericardium, the LV is estimated to contribute between 20% and 60% of the function of the RV.6 Despite this knowledge, the ventricular septum has been relatively ignored as a biventricular muscle region. It remains unknown how best to include this region in calculation of LV and RV function. Some experts advocate measuring RV and LV volumes at individual time-points of the cardiac cycle to identify the maximal diastolic volumes, while others ignore the extreme interventricular dependence and measure ventricular volumes when the septum is at the midline. Results will often be strikingly different and these differences in the timing of minimum and maximum ventricular volumes are particularly evident in disease states with disturbed electrical conduction as commonly seen in left bundle branch block or repaired TOF (Fig. 53.3). Therefore, for serial investigations, research studies, or just clinical consistency, these authors recommend selecting a lab preference and being consistent. To reiterate, these authors believe that interstudy and test–retest reproducibility is most important and, given the lack of a true gold standard, outweighs methods aimed entirely at accuracy. The evaluation of regional RV wall motion must take into consideration the normal variable contraction patterns near the moderator, parietal, and septomarginal

Echocardiography is and will likely remain a first-line diagnostic imaging modality for evaluating the RV structure and function because of its wide-spread availa bility and the fact that it is a noninvasive, rapid, and portable tool. It provides a comprehensive approach to assess patients with suspected right heart disease. Accurate evaluation of RV morphology and function requires integration of multiple echocardiographic views, including parasternal long- and short-axis, RV inflow, apical (RV modified) four-chamber, and subcostal views.10 Although multiple quantitative methods for RV assessment are provided, the routine assessment of RV structure and function is mostly qualitative or semiqua ntitative in clinical practice (Fig. 53.4). Nor mally, the cardiac apex is formed by the LV, but when significantly dilated, the RV is “apex-forming.” Methods commonly used to calculate the LV volume may be used to calculate RV volumes, but are less accurate due to the complex geometry. Due to these inherent limitations, a number of geometry-independent parameters have been proposed. Recently published guidelines on the echo evaluation of the right heart recognize that there are limitations in available published normal references and therefore, most categories are reported as normal or abnormal, rather than mild, moderate, or severe disease, which is common in reporting the left heart.11

M-MODE ECHOCARDIOGRAPHY The myofibrillar arrangement of the RV consists of mainly subepicardial circumferential fibers and subendocardial longitudinal fibers in the inflow region and both subepicardial and subendocardial longitudinal fibers in the outflow region. The majority of the RV myocardium


1137

Fig. 53.4: Echo windows for right ventricle (RV) assessment. Graphical illustration of the 11 recommended two-dimensional (2D) echocardiographic images from a transthoracic approach highlighting the parasternal long, parasternal short, apical, and subcostal views to obtain a comprehensive assessment of RV size and function. For additional details, see Rudski LG, et al. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2010;23:685–713.

lacks the middle circumferential myofiber array that is dominant in the LV and consequently is much more dependent on longitudinal shortening for global ejection than the LV.12 The longitudinal RV contraction at the base is important in understanding and estimating RV function. Because the predominant RV fractional shortening is significantly greater longitudinally than circumferentially, an evaluation of longitudinal shortening provides a rela tively simple and reliable estimate of global RV function. The total tricuspid annular descent or tricuspid annular plane systolic excursion (TAPSE) is an important marker of RV global systolic function (Fig. 53.5). Combining the findings from 46 studies investigating this value (N = 2320), the normal range can be reported as 22–24 mm (95% CI 15–31 mm).11 The TAPSE can be derived from M-mode analysis of the lateral tricuspid annular ring or from

Doppler tissue imaging (DTI) color display. Interestingly, for such a simple marker of RV function, the correlation between TAPSE and right ventricular ejection fraction (RVEF) by CMR was superior to first pass radionuclide techniques and three-dimensional (3D) echo estimates of RVEF in a single-center investigation of a population of patients with ischemia or pulmonary hypertension.13 However, this population had a relatively narrow RVEF range (58% ± 3%), there was significant variation in results, and despite having the best correlation coefficient, it was not high (r = 0.48). It is possible that the simplicity and relative reproducibility of this displacement parameter partially compensates for the single-dimensional nature that lowers the accuracy when regional RV dysfunction is present. Other clinical investigators studying more variable patient populations have found this real-world

1138


Fig. 53.5: Two different patients’ two-dimensional (2D) echocardiograms, apical four-chamber orientation (top row), diastolic (left) and systolic (right) frames, and associated M-mode from the right ventricle (RV) tricuspid annulus (bottom row). The patient displayed on the left has a normal RV and the patient displayed on the right has marked RV dilation and dysfunction. Arrows represent the systolic excursion of the tricuspid annular plane systolic excursion (TAPSE).

clinical value of TAPSE to remain when compared with 3D techniques (r = 0.64).14 Another potential consid eration might be that the TAPSE parameter, being single-dimensional and limited to the RV myocardial performance, at times is superior to 3D parameters. Since 3D methods will invariably include the curved ventricular septum, it is possible that the 3D data may contaminate the actual RV performance by including a component of LV contractile function. This is suggested by recent investigations of CMR parameters of RV displacement using a tagging sequence that approximates TAPSE.15 In this study, the investigators used CMR to demonstrate that the simple (and semiautomated) single-dimensional marker of RV function out-performed the 3D traditional parameter of RVEF (Fig. 53.6). This is an area of intense investigation in the hope of creating a potential automated and reliable CMR-based tool for quantifying RV function.16

TWO-DIMENSIONAL ECHOCARDIOGRAPHY The RV is typically smaller than the LV when normal, and normally viewed in the apical four-chamber view using 2D echo (2DE). However, it may be difficult to confirm the optimal alignment of these ventricles. Therefore, using relative dimensions as the sole criterion to diagnose RV

Fig. 53.6: Graphical comparison of tricuspid annular plane systolic excursion (TAPSE) and RVEF as measured by cardiac magnetic resonance imaging in normal controls, repaired tetralogy of Fallot, and patients with atrial septal defect and pulmonary hypertension. These authors found a greater ability of TAPSE over RVEF measures to separate right ventricle (RV) volume overload and RV pressure overload clinical syndromes. The y-axis is both percentage (for RVEF; red columns) and distance in millimeters (for TAPSE; blue columns). By multiplying the TAPSE value by 2.19, the TAPSE result is converted to a value that equals the normal controls RVEF (green columns) and further demonstrates the greater ability of TAPSE compared to RVEF to demonstrate statistical differences (P < 0.05). (ASD: Atrial septal defect; ASD + PHT: Atrial septal defect and pulmonary hypertension; TOF: repaired tetralogy of Fallot).

dilation is subject to significant potential error. Despite attempts to obtain orthogonal RV images necessary for volume calculations, most commonly using the apical four-chamber and subcostal views, it remains difficult to validate that they are orthogonal.17 Image acquisition should obtain the maximal diameter of the tricuspid valve annulus to ensure appropriate relative alignment and avoid cutting through the LV in a “noncenter” trajectory (Fig. 53.7). The RVOT is composed of a preponderance of circum ferential myofibers and carefully evaluating the motion in this region provides an estimate of global RV function. The RVOT fractional shortening (RVFS%) can be calculated as the percentage of the RVOT diastolic diameter minus the systolic diameter divided by the diastolic diameter. Either 2DE or M-mode echocardiography of the basal parasternal short-axis view at the level of the aortic root can be used and has been shown to correlate with TAPSE.18 Importantly, it closely correlates with other physiological events, such as the shortened pulmonary acceleration time recorded at the cusp level in patients with pulmonary hypertension.


Fig. 53.7: Two-dimensional (2D) echocardiogram, short-axis orientation, midventricular position (left), and accompanying schematic (inset). Images on the right represent the apical four-chamber cut-planes and accompanying schematic (inset). When aligned correctly through the midcavity of the left ventricle (LV: Solid white line), the LV/right ventricle (RV) ratio is > 1.5:1. When aligned incorrectly superior (dashed yellow line) or inferior (dashed pink line), this normal ratio may change and the normal RV may inadvertently appear relatively dilated. Although these lines are graphically displayed as parallel, in actual clinical practice these arise from the same transducer location point and are more divergent.

Global, systolic RV function can also be simply assessed quantitatively using 2DE as a percentage of change in the RV cavity area from end-diastole to end-systole in the apical four-chamber view. End-diastole is identified by the onset of the R-wave, whereas end-systole is regarded as the smallest RV cavity just before the tricuspid valve opening. Endocardial borders of the RV free wall and septum are traced from base to apex and the RV fractional area change (RV FAC) is defined using the following formula: (end-diastolic area – end-systolic area)/(end-diastolic area) × 100). Heavy RV trabeculation may render border tracing difficult and requires good image quality for accuracy. This technique incorporates the RV inflow tract and the apex but excludes the RVOT and may overestimate RV function if focal regional dysfunction (e.g. after surgical repair of TOF) exists in this region. Intravenous contrast agents designed for the LV may assist in image quality of the RV and may unmask RV thrombus (Fig. 53.8; Movie clip 53.6A). The percentage of RV FAC is a relatively simple parameter that is a surrogate marker of the RVEF and correlates well with CMR-derived RVEF (r = 0.80; Fig. 53.9).19

1139

Fig. 53.8: See Movie clip 53.6A. Contrast-enhanced two-dimensional echocardiogram, zoom apical four-chamber orientation, focused on the right ventricle (RV) apex. The center dark line represents the ventricular septum (myocardium). The unenhanced, well-circumscribed, 2.0 cm × 1.5 cm filling defect in the RV apex represents a large RV thrombus. The dark region toward the base of the RV cavity represents attenuation artifact from the dense manufactured contrast agent.

DOPPLER ECHOCARDIOGRAPHY Conventional Doppler Importantly, all conventional Doppler techniques are subject to increased error as the quality of the spectral Doppler signal worsens and therefore, special care should be taken during image acquisition. The rate of RV pressure increase is derived from the continuous wave Doppler (CWD) spectral display of the TR signal. The time interval (dt) necessary to increase the TR velocity from baseline to 2.0 m/s represents a change in pressure (dP) of 16 mm Hg. When the TR velocity is elevated, time intervals from 1.0 m/s to 2.5 or 3.0 m/s (dP = 21 mm Hg and 32 mm Hg, respectively) can alternatively be obtained (similar to LV dP/dt estimates) and reduce error from using very low velocities. The dP/dt value is considered normal when >400 mm Hg/s (Fig. 53.10).20 Since the dP/dt is dependent on preload, the maximal TR velocity (TRmax) can be included in the equation (dP/dt/TRmax) and partially compensate for this.21 In patients with predominant RV failure, the TRderived dP/dt/TRmax, but not dP/dt alone, was shown to be a clinically useful index of global RV contractility.

1140


Fig. 53.9: Two-dimensional (2D) echocardiogram, apical fourchamber orientation, diastolic (left) and systolic frame (right). The right ventricle (RV) endocardial border has been traced for estimating the volumes (and calculating the fractional area change [FAC]) using the Simpson’s method of discs. In this patient with severe global RV systolic dysfunction, the FAC was 13%. (FAC: Fractional area change; RVd: RV diastolic volume; RVs: RV systolic volume).

The pulsed wave Doppler (PWD) spectral display of the RV inflow can be used as an estimate of RV diastolic function. Similar to LV inflow patterns, peak early velocity (E-wave) and its deceleration time, late velocity during atrial contraction (A-wave) and its duration, are parameters that reflect right-heart pathology. The hepatic and vena cava PWD patterns also reflect RV hemodynamics and increased right-sided heart filling pressures lead to increased flow reversal in the hepatic vein (HV > 20%) or superior vena cava (SVC > 10%) during apnea. Increased flow reversals in response to inspiration or expiration can be seen in patients with restrictive or constrictive cardiomyopathies, respectively.22,23

Tissue Doppler The pulmonary circulation normally has a low vascular resistance, and consequently, a very short (or unde tectable) isovolumic contraction time (IVCT) and isovo lumic relaxation time (IVRT). The superficial circum ferential fibers contract during the IVCT and the deeper longitudinal fibers contract during ejection. The onset of RV ejection at the outflow tract is delayed after the onset of contraction of the inflow tract. This regional RV contractility requires high temporal resolution to be recognized and provides a basis for color mapping of the myocardium with advanced tissue Doppler or speckle tracking techniques.

Fig. 53.10: Top Left: Two-dimensional (2D) echocardiogram, short-axis orientation, midventricular level demonstrating a markedly dilated right ventricle (RV), concave septum toward the left ventricle (LV), and RVH in a patient with severe pulmonary hypertension and a reduced RV dP/dt of 320 mm Hg/s. Bottom left: Continuous wave Doppler spectral display of the tricuspid regurgitation (TR) signal confirming the elevated TR maximal velocity (> 5 m/s; >100 mm Hg). Right panel: Zoom image of the TR spectral continuous wave Doppler (CWD) display used to estimate the dP/dt. White arrow = TR flow at 1 m/s (4 mm Hg); Black arrow = TR flow at 3 m/s (36 mm Hg); ΔP = estimated change in pressure from 1 to 3 m/s; Δt = measured time from 1 m/s to 3 m/s; TRmax = maximal TR velocity.

Tissue Doppler can be used to record the peak systolic velocity of the tricuspid annulus (S'). In healthy individuals, the lower normal limit at the basal RV lateral wall is ≥ 14 ± 2 cm/s for DTI spectral displays and ≥ 10 ± 2 cm/s for DTI color displays. This velocity has been shown to correlate more closely with CMR-derived RVEF than the 2D fractional area change (FAC), DTI-derived tissue displacement, systolic strain, and strain rate.24 An S' < 9.5 cm/s identifies patients with an RVEF < 40%.25 Thresholds of > 12, 12–9, and < 9 cm/s allow differentiation between normal (> 55%), moderately reduced (30–55%), and severely reduced (< 30%) RVEF, respectively.26 Myocardial velocity of the RV free wall as measured by DTI during the IVCT phase (IVCv) has also been used to estimate RV contractility (Fig. 53.11). Although this parameter appears more sensitive to loading conditions than myocardial acceleration and other listed parameters, this parameter demonstrated the ability to predict outcomes in patients with pulmonary artery hypertension (PAH).27 In 142 patients with PAH, the 6-minute walk test (≤ 400 M) and IVCv (≤ 9 cm/s) were the only clinical or echo parameters that predicted mortality. Myocardial acceleration during the earliest phase of IVCT is a novel


1141

Fig. 53.11: Two-dimensional (2D) echocardiogram, apical fourchamber orientation, tissue Doppler color map display of mean myocardial displacement (derivative of velocity/time). The arrow points to the basal right ventricle (RV) myocardial region, which we have found should remain purple (≥ 12 mm) for approximately 50% of the length of the RV free wall in normal individuals. This is a quick semiquantitative tool that appears to correlate with tricuspid annular plane systolic excursion (TAPSE).

Fig. 53.12: Illustration of tissue Doppler spectral display of the right ventricle (RV) tricuspid annulus highlighting the RV myocardial movements and representative measurements during the entire cardiac cycle. Inset: Actual tissue Doppler spectral display of the RV tricuspid annulus in a patient. (Ea: Early diastolic velocity of the RV annulus that occurs during early RV filling; Aa: Late diastolic velocity of the RV annulus that occurs during the atrial contraction; Sa: Systolic velocity of the RV annulus that occurs during RV systolic contraction; IVCT: Isovolumic contraction time; IVRT: Isovolumic relaxation time; IVV: Isovolumic velocity; At: Time to reach maximal IVV.

index for the assessment of RV contractile function that is less affected by preload and afterload changes.28 This index is calculated by dividing myocardial velocity during IVCT by the time interval from the onset of this wave to the time at peak velocity. The RV index of myocardial performance (RIMP; or Tei index) is defined as the sum of the IVCT and IVRT divided by the ejection time and is increased in either systolic or diastolic RV dysfunction.29 This parameter is relatively simple to obtain with high quality tissue Doppler or conventional PWD, is a marker of early disease in cardiac amyloidosis, and predicts symptoms in hypertrophic cardiomyopathy (Figs 53.12 and 53.13).30 A value < 0.25 predicts an RVEF ≥ 0.50 (sensitivity 70%, specificity 89%) and ≥ 0.40 predicts an RVEF < 35% (81%, 85%).31

(near the apex) myofibers.4 Unlike tissue Doppler analysis which is subject to error from cursor angle misalignment, 2D strain (speckle tracking) is angle-independent, allowing for the evaluation of regional function in all myocardial segments (including the apex). Ultrasound of the myocardium has natural small variations in decibels (speckles) that are inherent to the characterization of the RV wall and can be tracked throughout the cardiac cycle. These provide a detailed regional determination of frameto-frame myocardial deformation. Peak systolic strain and strain rate, particularly of the basal RV free wall, are significantly impaired in patients with pulmonary arterial hypertension and have been used as an index of global RV function.32 The longitudinal RV strain and strain rate values are higher and more inhomogeneous than values reported for the LV. Longitudinal strain and strain rate values are lowest in the RV base and increase toward the RV apex. Strain rate imaging is independent of overall motion. This technique has significant potential as the initial and serial diagnostic tool to assess patients with known or suspected RV pathology, and correlates with invasive and noninvasive reference standards of RV performance (Figs 53.14A and B).33,34 Moreover, strain rates are much

TWO-DIMENSIONAL STRAIN (SPECKLE TRACKING) The RV myocardium is normally only 3–4 Within this thin layer of myocardium resides arrangement of circumferential (parallel to valve (AV) groove and encircling the RVOT)

mm thin. a complex the aortic and spiral

1142


Fig. 53.13: Pulsed wave Doppler (PWD) spectral display of the right ventricle (RV) inflow (upper left insert) and RV outflow (lower right insert) and an illustrative drawing of these Doppler displays demonstrating an alternative method from Figure 53.12 to calculate the Tei index. (E: RV inflow early diastolic wave; A: RV inflow late (atrial) diastolic wave; TRd: Tricuspid regurgitation duration; ET: RV ejection time; RVOT: Right ventricular outflow tract PWD flow; IVCT: Isovolumic contraction time; IVRT: Isovolumic relaxation time; IMP: Index of myocardial performance.

A

B

Figs 53.14A and B: Two-dimensional (2D) echocardiogram, apical four-chamber orientation, angulated slightly rightward to visualize the entire right ventricle (RV) apex with 2D strain color map (speckle tracking) display of the RV myocardium. A. Diastolic frame (arrow = apical variant hypertrophic cardiomyopathy); B. Systolic frame (arrow = abnormal distal ventricular septum due to adjacent pathological LV myocardium). For additional details, see Abdy NA, et al. Apical Hypertrophic Cardiomyopathy in an Adolescent. Congen Heart Dis. 2010;5(2):182–87.

less load-dependent than strains, volumes, or ejection fraction, which is particularly important in the RV, where preload varies significantly with respiration.35 Recently, velocity vector imaging of the RV (longitu dinal strain), was used to predict RV failure after left ventricular assist device placement. In this report, a peak strain cutoff of –9.6% predicted RV failure with 76% specificity and 68% sensitivity.36

THREE-DIMENSIONAL ECHOCARDIOGRAPHY In the absence of cardiac shunting (or significant atrioven tricular valve regurgitation), the LV and RV have the same

stroke volume, but the upper limit of normal RV volume is greater than the LV. This explains why the lower limit of normal RVEF is lower than the left ventricular ejection fraction (LVEF; e.g. RV in diastole, 100 mL; RV in systole, 55 mL; RV stroke volume, 45 mL; RVEF = 45/100 = 45%; LV in diastole, 90 mL; LV in systole, 45 mL; LV stroke volume, 45 mL; LVEF = 45/90 = 50%). Three-dimensional echocardiography analysis of the RV has recently been reported as a means to eliminate the geometric intricacies of the RV. Real time 3D echo (RT3DE) has recently become a reliable, reproducible tool to measure the LV. Although less well reported, this technique provides an evaluation of the RV independent of geometric assumptions.37 The RV volumes and RVEF are


1143

Table 53.1: Normal Right Ventricular Volume/Body Surface Area

Volume

CMR (mL/m2)

RT3DE (mL/m2)

n

Mean (SD)

Mean (SD)

EDV: ● All

71

71.3 (12.9)

70.0 (12.9)

Male

36

67.1 (12.1)

56.4 (13.4)

● Female

35

75.6 (12.4)

74.7 (13.0)

All

71

33.5 (9.9)

33.4 (10.3)

● Male

36

28.6 (8.1)

29.2 (10.7)

35

38.4 (9.1)

37.8 (7.4)

●

ESV: ●

●

Female

RVEF: ●

All

71

53.3 (8.7)

52.6 (9.9)

●

Male

36

57.5 (7.0)

56.2 (9.1)

●

Female

35

49.0 (8.8)

48.9 (9.5)

Normal right ventricular volumes (indexed to body surface area) as measured with CMR and RT3DE categorized by gender to enddiastolic and end-systolic volumes and the resulting RVEF. Table modified from Reference 38. For additional details, see Gopal AS, et al. Normal values of right ventricular size and function by real time three-dimensional echocardiography: comparison to cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20:445–55. (CMR: Cardiac magnetic resonance imaging; EDV: End-diastolic volume; ESV: End-systolic volume; RT3DE: Real time three-dimensinal echocardiography; RVEF: Right ventricular ejection fraction).

determined by manual tracing of the endocardial borders and require adequate image quality for this purpose. However, due to the fact that the entire RV is acquired in a single pyramidal data set, any acoustic window may be used and this increases the likelihood that an adequate image is obtained. Head-to-head comparison of 3D techniques to 2D techniques consistently demonstrate larger volumes and closer agreement as well as higher reproducibility relative to CMR. Normal RT3DE values of the RV size and function have been reported (Table 53.1).38 The technique of RT3DE has been validated in phantoms, animals studies, adults with acquired RV pathology, and children with congenital heart diseases.39

TRANSESOPHAGEAL ECHOCARDIOGRAPHY When the transthoracic ultrasound window is suboptimal and CMR is not available, transesophageal echo (TEE) may be performed. Most reports on TEE evaluation of the RV are from intraoperative studies and may not be as clinically relevant due to the frequent administration of inotropic medications and rapid fluid shifts in this population. In a study of 25 children operated on for ASDs, 90% had adequate 3D TEE studies.40 RV volumes with this

technique matched the direct surgical measures (r2 = 0.99) obtained by injecting saline solution through the tricuspid valve using a graduated syringe. In the clinical setting of tricuspid or pulmonic valve pathology, TEE is a valuable complementary diagnostic tool.

HEMODYNAMICS Although not a direct estimate of RV volume or function, the evaluation of right heart hemodynamics is exceedingly valuable when right heart pathology is suspected. The right atrial pressure (RAP) is readily estimated from the inferior vena cava (IVC) dynamics and the caval and HV flows. More recently, DTI has also been used to evaluate this parameter. Classically, a dilated IVC, lack of inspiratory collapse, E/e' ratio > 6, atrial septal leftward bulge, predominant diastolic flow patterns in the SVC, or HVs suggest an elevated RAP. However, these features may be normal in athletes, obese individuals, congenital narrowing of the IVC–RA junction (Budd–Chiari), cor triatriatum dexter, or mechanical ventilation. Importantly, IVC imaging should be performed in the supine (not left lateral decubitus) position. For specific RAP values, it is somewhat reliable to use 0–20 mm Hg range at 5 mm Hg intervals. If the IVC size is < 21 mm and the inspiratory

1144


RAP or LV systolic pressure (cuff pressure in absence of outflow gradients), and provide an avenue to noninvasively estimate intracardiac pressures.44

OTHER IMAGING MODALITIES

Fig. 53.15: See Movie clip 53.9. Cardiac magnetic resonance imaging, diastolic frame from a cine image, four-chamber long-axis orientation, demonstrating the clarity of the right ventricle (RV) that is expected despite body habitus or lung disease that often limits the visualization of echocardiography. Chamber size and ejection fraction can be measured by obtaining multiple slices that covers the entire RV and manually tracing the endocardial borders.

narrowing is > 50%, the RAP is 0–5 mm Hg. Use 5 mm Hg if any other signs of elevated RAP exist. If either one of these two parameters is abnormal, use 5–10 mm Hg (10 mm Hg if other signs exist). If both size and respiratory variation are abnormal, use 15 mm Hg (or 20 mm Hg if IVC plethora exists). The dynamic inspiratory change > 50% is more important than the IVC size.41 In mechanically ventilated individuals, more complex assessment is necessary to estimate RAP, such as the HV systolic filling fraction (HVFF = VsVTI/VdVTI) < 55%, which has a sensitivity and specificity of 86% and 90%, respectively, for diagnosing RAP > 8 mm Hg.42 [VsVTI: Systolic (hepatic) venous velocity time integral; VdVTI: Diastolic (hepatic) venous velocity time integral]. Another formula successfully used in mechanically ventilated patients incorporates the tricuspid inflow and DTI of the tricuspid annulus: 1.62 E/e' + 2.13 = RAP (r = 0.7).43 This was assessed in patients with recent cardiac surgery. When apnea cannot be performed for these right-sided measurements, averaging multiple Doppler velocities appears to be an adequate alternative. Careful scrutiny of the transvalvular (when regur gitation exists) or trans-septal (when shunts exist) gradients provide the means to determine pressure gradients across cardiac chambers. These gradients are then added or subtracted to known pressures, such as the

Extensive review of multimodal imaging of the RV is available elsewhere, but a brief update on the capabilities of CMR and computed tomography is worthwhile to provide the reader with an understanding of these contemporary diagnostic imaging capabilities.45,46 The development of CMR has advanced significantly over the past two decades. Since CMR is not limited by the ultrasound acquisition window, the entire RV can be easily visualized (Fig. 53.15 and Movie clip 53.9). This allows qualitative assessment of right ventricular wall motion and reliable quantitative assessment of chamber size, mass, and ejection fraction, and is considered the reference standard when assessing new echo techniques.47 These properties have made CMR a valuable tool in the assessment of primary RV cardiomyopathies and cor pulmonale.48,49 CMR can also be used to evaluate vascular anatomy and quantify blood flow and is an important tool in the evaluation of patients with complex congenital heart disease.50,51 Despite being considered a reference standard due to the excellent interstudy reproducibility and lack of a gold standard, highly skilled technologists and interpreting physicians are as necessary for CMR studies as they are for echo studies. A vital aspect of CMR is the ability to evaluate tissue characteristics. RV infarction can be easily detected with late gadolinium contrast-enhancement imaging.52,53 This CMR sequence has also been demonstrated to be a reliable way to assess thrombus, not uncommonly found in the RV.54–56 Yet another important strength of CMR for quantification of RV function is the ability to quantify regional and global RV mechanics (such as strains and strain rates) using techniques such as myocardial tagging.57 However, due to the thin walls of the RV, tagging methods are mostly limited to assessment of longitudinal RV deformation. However, newer MRI techniques such as cine displacement encoding with stimulated echoes (DENSE) show promise in their ability to acquire full 3D data sets for quantification of circumferential and longitudinal strain in the RV from a single data set.9 Despite these strengths, CMR is still mostly limited to patients without pacemakers or defibrillators and not severely claustrophobic, although it is becoming increasingly recognized that CMR is safe in patients with


Fig. 53.16: See Movie clip 53.10. Cardiac CTA displayed in the four-chamber orientation demonstrating the clearly defined border between the brighter blood pool and the darker right ventricular myocardium.

these devices.58 Even when CMR is proven to be entirely safe in patients with pacemakers, the RV lead will create havoc for optimal imaging of the RV by producing a ferromagnetic artifact, limiting optimal visualization of the RV wall near the lead. Gadolinium contrast use is limited to patients without severe renal insufficiency [Glomerular filtration rate (GFR) > 30 mL/min/1.73 m2] due to the increased risk of nephrogenic systemic fibrosis. Optimal imaging is achieved when patients are in normal sinus rhythm and able to breath-hold for 7–15 seconds, which may not be possible in patients with significant right heart pathology. Real time or single-shot imaging can be performed in these patients in much shorter times or during free breathing but at a cost of reduced spatial resolution. Similar to echocardiography, it is important to have experienced specialists acquire high quality, comprehensive images to maximize the clinical value of the study. Cardiovascular computed tomography (CCT) can also be valuable in the assessment of the RV. With high spatial resolution (approximately 0.5 mm), the right ventricular anatomy, chamber size, and systolic function can be accurately determined (Fig. 53.16 and Movie clip 53.10).59 Since CCT obtains a volumetric data set with isotropic voxels, images can be reoriented in any plane for postacquisition evaluation. In patients with congenital heart disease, who are unable to undergo CMR, CCT offers an alternative noninvasive imaging option.60 Since blood has similar signal intensity as myocardium on noncontrast CCT, injection of contrast is necessary to

1145

differentiate the myocardium from blood. Depending on the area of interest, the site of contrast injection (intravenous line placement), contrast injection rate and volume, and timing of the scan need to be carefully considered to optimize opacification of the vascular structures or cardiac chamber of interest. This is especially important in the evaluation of the RV since intravenous contrast is injected via a peripheral vein, and is mixed with noncontrast blood from other peripheral veins (e.g. IVC flow) prior to entering the RV. This can lead to incomplete contrast/blood mixing and limit the optimal evaluation. Despite the high spatial resolution that can be acquired with CCT, this technique is limited by low temporal resolution (> 80 ms), need for ionizing radiation, and nephrotoxic contrast agents. Lastly, invasive RV angiography could be considered the reference standard, but like all imaging modalities require specialized skills at acquiring adequate orientation and contrast filling of the RV. Some investigators have had success at creating quantitative off-line spline models of regional contraction patterns to help separate normal from abnormal motion patterns.61

CONCLUSION Continued investigation is warranted to improve our understanding of the RV and to obtain robust noninvasive diagnostic methods to assess this chamber, which continues to be proven to predict clinical outcomes. Evolving clinical settings demonstrate the importance of evaluating the RV in an effort to predict RV failure such as prior to left ventricular assist devices. Given the normally complex shape, the further distortion with pathology, and the intricate myofibrillar arrangement, it is likely that a combination of parameters (possibly imaging and clinical) will need to be used for optimal RV assessment rather than a single diagnostic parameter. It may also be necessary to combine diagnostic imaging tools, but for the foreseeable future, echo will be the initial technique for this purpose.

DISCLOSURE Gadolinium contrast is not Food and Drug Administration (FDA) approved for CMR.

REFERENCES 1. Oosterhof T, van Straten A, Vliegen HW, et al. Preoperative thresholds for pulmonary valve replacement in patients with corrected tetralogy of Fallot using cardiovascular magnetic resonance. Circulation. 2007;116(5):545–51.

1146


2. Puchalski MD, Williams RV, Askovich B, et al. Assessment of right ventricular size and function: echo versus magnetic resonance imaging. Congenit Heart Dis. 2007;2(1):27–31. 3. Marcus FI, Fontaine GH, Guiraudon G, et al. Right ventricular dysplasia: a report of 24 adult cases. Circulation. 1982;65(2):384–98. 4. Haddad F, Hunt SA, Rosenthal DN, et al. Right ventricular function in cardiovascular disease, part I: Anatomy, physiology, aging, and functional assessment of the right ventricle. Circulation. 2008;117(11):1436–48. 5. Santamore WP, Dell’Italia LJ. Ventricular interdependence: significant left ventricular contributions to right ventricular systolic function. Prog Cardiovasc Dis. 1998;40(4):289–308. 6. Janicki J, Shroff S, Weber K. Ventricular interdependence. In: Scharf S, Cassidy S, editors. Heart–Lung Interactions in Health and Disease. New York. NY: Marcel Dekker, 1989:285–308. 7. Marcus F, Basso C, Gear K, et al. Pitfalls in the diagnosis of arrhythmogenic right ventricular cardiomyopathy/ dysplasia. Am J Cardiol. 2010;105(7):1036–9. 8. Bluemke DA, Krupinski EA, Ovitt T, et al. MR Imaging of arrhythmogenic right ventricular cardiomyopathy: morph ologic findings and interobserver reliability. Cardiology. 2003;99(3):153–62. 9. Auger DA, Zhong X, Epstein FH, et al. Mapping right ventricular myocardial mechanics using 3D cine DENSE cardiovascular magnetic resonance. J Cardiovasc Magn Reson. 2012;14:4. 10. Horton KD, Meece RW, Hill JC. Assessment of the right ventricle by echocardiography: a primer for cardiac sono graphers. J Am Soc Echocardiogr. 2009;22(7):776–92; quiz 861. 11. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685–713; quiz 786. 12. Sanchez-Quintana D, Anderson RH, Ho SY. Ventricular myoarchitecture in tetralogy of Fallot. Heart. 1996;76(3): 280–6. 13. Kjaergaard J, Petersen CL, Kjaer A, et al. Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI. Eur J Echocardiogr. 2006;7(6):430–8. 14. Nijveldt R, Germans T, McCann GP, et al. Semi-quantitative assessment of right ventricular function in comparison to a 3D volumetric approach: a cardiovascular magnetic resonance study. Eur Radiol. 2008;18(11):2399–405. 15. Chen SS, Keegan J, Dowsey AW, et al. Cardiovascular magnetic resonance tagging of the right ventricular free wall for the assessment of long axis myocardial function in congenital heart disease. J Cardiovasc Magn Reson. 2011;13:80. 16. Naik SL, Rodriguez JJ, Kalra N, et al. Tricuspid annular plane systolic excursion (TAPSE) revisited using CMR. J Cardiovasc Magn Res. 2012;14(Suppl 1):P299.

17. Levine RA, Gibson TC, Aretz T, et al. Echocardiographic measurement of right ventricular volume. Circulation. 1984;69(3):497–505. 18. Lindqvist P, Henein M, Kazzam E. Right ventricular outflow-tract fractional shortening: an applicable measure of right ventricular systolic function. Eur J Echocardiogr. 2003;4(1):29–35. 19. Anavekar NS, Gerson D, Skali H, et al. Two-dimensional assessment of right ventricular function: an echocar diographic-MRI correlative study. Echocardi ography. 2007;24(5):452–6. 20. Anconina J, Danchin N, Selton-Suty C, et al. Noninvasive estimation of right ventricular dP/dt in patients with tricuspid valve regurgitation. Am J Cardiol. 1993;71(16): 1495–7. 21. Kanzaki H, Nakatani S, Kawada T, et al. Right ventricular dP/dt/P(max), not dP/dt(max), noninvasively derived from tricuspid regurgitation velocity is a useful index of right ventricular contractility. J Am Soc Echocardiogr. 2002;15(2):136–42. 22. Klein AL, Hatle LK, Burstow DJ, et al. Comprehensive Doppler assessment of right ventricular diastolic function in cardiac amyloidosis. J Am Coll Cardiol. 1990;15(1): 99–108. 23. Appleton CP, Jensen JL, Hatle LK, et al. Doppler evaluation of left and right ventricular diastolic function: a technical guide for obtaining optimal flow velocity recordings. J Am Soc Echocardiogr. 1997;10(3):271–92. 24. Wang J, Prakasa K, Bomma C, et al. Comparison of novel echocardiographic parameters of right ventricular function with ejection fraction by cardiac magnetic resonance. J Am Soc Echocardiogr. 2007;20(9):1058–64. 25. De Castro S, Cavarretta E, Milan A, et al. Usefulness of tricuspid annular velocity in identifying global RV dysfunction in patients with primary pulmonary hypertension: a comparison with 3D echo-derived right ventricular ejection fraction. Echocardiography. 2008;25(3): 289–93. 26. Tüller D, Steiner M, Wahl A, et al. Systolic right ventricular function assessment by pulsed wave tissue Doppler imaging of the tricuspid annulus. Swiss Med Wkly. 2005;135(31– 32):461–8. 27. Ernande L, Cottin V, Leroux PY, et al. Right isovolumic contraction velocity predicts survival in pulmonary hypertension. J Am Soc Echocardiogr. 2013;26(3):297–306. 28. Vogel M, Schmidt MR, Kristiansen SB, et al. Validation of myocardial acceleration during isovolumic contraction as a novel noninvasive index of right ventricular contractility: comparison with ventricular pressure-volume relations in an animal model. Circulation. 2002;105(14):1693–9. 29. Kim WH, Otsuji Y, Yuasa T, et al. Evaluation of right vent ricular dysfunction in patients with cardiac amyloidosis using Tei index. J Am Soc Echocardiogr. 2004;17(1):45–9. 30. Mörner S, Lindqvist P, Waldenström A, et al. Right ventr icular dysfunction in hypertrophic cardiomyopathy as evidenced by the myocardial performance index. Int J Cardiol. 2008;124(1):57–63.


31. Schwerzmann M, Samman AM, Salehian O, et al. Comparison of echocardiographic and cardiac magnetic resonance imaging for assessing right ventricular function in adults with repaired tetralogy of fallot. Am J Cardiol. 2007;99(11):1593–7. 32. Pirat B, McCulloch ML, Zoghbi WA. Evaluation of global and regional right ventricular systolic function in patients with pulmonary hypertension using a novel speckle tracking method. Am J Cardiol. 2006;98(5):699–704. 33. Teske AJ, De Boeck BW, Olimulder M, et al. Echocar diographic assessment of regional right ventricular function: a head-to-head comparison between 2-dimensional and tissue Doppler-derived strain analysis. J Am Soc Echo cardiogr. 2008;21(3):275–83. 34. Abdy NA, Valdes SO, Sorrell VL, et al. Apical hypertrophic cardiomyopathy in an adolescent. Congenit Heart Dis. 2010;5(2):182–187. 35. Weidemann F, Jamal F, Sutherland GR, et al. Myocardial function defined by strain rate and strain during alterations in inotropic states and heart rate. Am J Physiol Heart Circ Physiol. 2002;283(2):H792–H799. 36. Grant AD, Smedira NG, Starling RC, et al. Independent and incremental role of quantitative right ventricular evaluation for the prediction of right ventricular failure after left ventricular assist device implantation. J Am Coll Cardiol. 2012;60(6):521–8. 37. Jenkins C, Chan J, Bricknell K, Strudwick M, Marwick TH. Reproducibility of right ventricular volumes and ejection fraction using real-time three-dimensional echocardiography: comparison with cardiac MRI. Chest. 2007;131(6):1844–51. 38. Gopal AS, Chukwu EO, Iwuchukwu CJ, et al. Normal values of right ventricular size and function by real-time 3-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20(5):445–55. 39. Shiota T. 3D echocardiography: evaluation of the right ventricle. Curr Opin Cardiol. 2009;24(5):410–4. 40. Grison A, Maschietto N, Reffo E, et al. Three-dimensional echocardiographic evaluation of right ventricular volume and function in pediatric patients: validation of the technique. J Am Soc Echocardiogr. 2007;20(8):921–9. 41. Kircher BJ, Himelman RB, Schiller NB. Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava. Am J Cardiol. 1990;66(4):493–6. 42. Nagueh SF, Kopelen HA, Zoghbi WA. Relation of mean right atrial pressure to echocardiographic and Doppler parameters of right atrial and right ventricular function. Circulation. 1996;93(6):1160–9. 43. Sade LE, Gulmez O, Eroglu S, et al. Noninvasive estimation of right ventricular filling pressure by ratio of early tricuspid inflow to annular diastolic velocity in patients with and without recent cardiac surgery. J Am Soc Echocardiogr. 2007;20(8):982–8.

1147

44. Sorrell VL, Reeves WC. Noninvasive right and left heart catheterization: taking the echo lab beyond an image-only laboratory. Echocardiography. 2001;18(1):31–41. 45. Selton-Suty C, Juillière Y. Non-invasive investigations of the right heart: how and why? Arch Cardiovasc Dis. 2009;102(3):219–32. 46. Sorrell VL, Indik JI, Marcus FI. Right ventricular cardio myopathies. Section III. Chapter 19. Cardiovascular multimodal imaging in key clinical problems. In: Pahlm O, Wagner G, editors. Multimodal Cardiovascular Imaging: Principles and Clinical Applications. McGraw-Hill; 2011. 47. Grothues F, Moon JC, Bellenger NG, et al. Interstudy reproducibility of right ventricular volumes, function, and mass with cardiovascular magnetic resonance. Am Heart J. 2004;147(2):218–23. 48. Marcus FI, McKenna WJ, Sherrill D, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/ dysplasia: proposed modification of the task force criteria. Circulation. 2010;121(13):1533–41. 49. Bradlow WM, Gibbs JS, Mohiaddin RH. Cardiovascular magnetic resonance in pulmonary hypertension. J Cardiovasc Magn Reson. 2012;14:6. 50. Warnes CA, Williams RG, Bashore TM, et al.; American College of Cardiology; American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults with Congenital Heart Disease); American Society of Echo cardiography; Heart Rhythm Society; International Society for Adult Congenital Heart Disease; Society for Cardiovascular Angiography and Interventions; Society of Thoracic Surgeons. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults with Congenital Heart Disease). Developed in Collaboration with the American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2008;52(23):e143–e263. 51. Sorrell VL, Altbach MI, Kudithipudi V, et al. Cardiac MRI is an important complementary tool to Doppler echocar diography in the management of patients with pulmonary regurgitation. Echocardiography. 2007;24(3): 316–28. 52. Kumar A, Abdel-Aty H, Kriedemann I, et al. Contrastenhanced cardiovascular magnetic resonance imaging of right ventricular infarction. J Am Coll Cardiol. 2006;48(10): 1969–76. 53. Lockie T, Nagel E, Redwood S, et al. Use of cardiovascular magnetic resonance imaging in acute coronary syndromes. Circulation. 2009;119(12):1671–81. 54. Weinsaft JW, Kim RJ, Ross M, et al. Contrast-enhanced anatomic imaging as compared to contrast-enhanced tissue characterization for detection of left ventricular thrombus. JACC Cardiovasc Imaging. 2009;2(8):969–79.

1148


55. Boukantar M, Lim P, Mitchell-Heggs L. Right ventricular thrombus and pulmonary embolism in patient with anterior myocardial infarction. Eur Heart J. 2010;31(23):2870. 56. Tsang BK, Platts DG, Javorsky G, e al. Right ventricular thrombus detection and multimodality imaging using contrast echocardiography and cardiac magnetic resonance imaging. Heart Lung Circ. 2012;21(3):185–8. 57. Haber I, Metaxas DN, Geva T, Axel L. Three-dimensional systolic kinematics of the right ventricle. Am J Physiol Heart Circ Physiol. 2005;289(5):H1826–H1833. 58. Gimbel JR, Bello D, Schmitt M, et al.; Advisa MRI System Study Investigators. Randomized trial of pacemaker and lead system for safe scanning at 1.5 Tesla. Heart Rhythm. 2013;10(5):685–91.

59. Raman SV, Shah M, McCarthy B, et al. Multi-detector row cardiac computed tomography accurately quantifies right and left ventricular size and function compared with cardiac magnetic resonance. Am Heart J. 2006;151(3): 736–44. 60. Huang X, Pu X, Dou R, et al. Assessment of right ventricular function with 320-slice volume cardiac CT: comparison with cardiac magnetic resonance imaging. Int J Cardiovasc Imaging. 2012;28(Suppl 2):87–92. 61. Indik JH, Wichter T, Gear K, et al. Quantitative assess ment of angiographic right ventricular wall motion in arrhythmogenic right ventricular dysplasia/cardiomy opathy (ARVD/C). J Cardiovasc Electrophysiol. 2008;19(1): 39–45.

CHAPTER 54 Three-Dimensional Echocardiographic Assessment of LV and RV Function Aasha S Gopal

Snapshot  3D QuanƟtaƟon of the LeŌ Ventricle

INTRODUCTION Significant progress has taken place in the last 25 years in moving echocardiography from a two-dimensional (2D) imaging modality to a three-dimensional (3D) imaging modality that has found several routine clinical applications, an important one being quantification of cardiac structure and function. This progress has closely paralleled the transition in transducer technology from conventional phased-array transducers to matrix array transducers. This chapter explores the limitations of quantifying left and right ventricular (RV) structure and function by conventional M-mode [one-dimensional (1D)] and 2D echocardiography (2DE), thereby providing the rationale for developing and adopting new methods such as 3D echocardiography (3DE) and speckle tracking echocardiography (STE).

3D QUANTITATION OF THE LEFT VENTRICLE Limitations of 2D Echocardiography— Lack of 3D Spatial Coordinates Left ventricular ejection fraction (LVEF) is a cardinal parameter that has been shown to have tremendous prognostic value in a variety of clinical situations varying from valvular heart disease, ischemic heart disease

 3D QuanƟtaƟon of the Right Ventricle

to cardiomyopathies. Despite its central importance, evaluation of left ventricular (LV) structure and function in routine clinical practice is largely subjective and substantially relies on an expert knowledge of cardiac anatomy and physiology. The clinician integrates this knowledge, views moving 2D cross-sectional images, and renders an eyeball estimation of LVEF as a first approximation. Indeed, in the hands of experts, this method compares quite favorably when compared to many traditional M-mode and 2D techniques.1 However, there is substantial interoperator variability and standardization is difficult. More objective measures of chamber quantification rely on detection of endocardial borders at end-diastole and end-systole. Linear dimensions may be obtained by M-mode echocardiography that has excellent temporal resolution, or by 2DE. Linear dimensions are still reported today because of simplicity of use. However, these dimensions have high test–retest variability largely because of image positioning error, that is, the difficulty faced by the sonographer to reproduce the same 2D echocardiographic image with a high degree of fidelity.2 This is because, standard 2D images are prescribed by the sonographer solely on their basis of their knowledge of cardiac anatomy and are not based on any external 3D spatial coordinate system. An external 3D spatial coordinate system can be specified by a variety of methods and the very early prototypes of 3DE systems utilized either an acoustic

1150


or magnetic system of emitters and receivers that were mounted on the transthoracic imaging transducer (Figs 54.1 and 54.2).3–5 Using such a system, it was noted that only 24% of unguided standard images are optimally positioned within ±5 mm and ±15° of the ideal position and 3DE improves positioning of standard images to 80%, a threefold improvement (p < 0.001).2 If the standard parasternal long-axis view is positioned with a high degree of variability, measurements obtained from these

Fig. 54.1: Freehand scanning. An external three-dimensional (3D) spatial coordinate system is provided by an acoustic spatial locater which consists of a system of three sound emitters mounted on the transducer (shown on the examination bed) which provides freehand scanning. These emit sound waves that are received by an overhead microphone array (shown above the examination bed). The 3D spatial information is fed into a computer (shown beside the ultrasound machine) which assigns a set of x, y, and z Cartesian coordinates to each image.

A

B

views also exhibit a high degree of variability. A study showed that the standard unguided 2D examination was associated with an interobserver variability of 9.1% for ventricular measurements. Guided 3DE significantly reduced interobserver variability to 3.1% for the same measurements (p < 0.005 by McNemar’s test).6 The lack of 3D spatial coordinates by conventional echocardiography also means that it is not possible to relate one cross-sectional image with another crosssectional image without making assumptions related to image position that is, biplane images are assumed to be orthogonal to each other but rarely ever satisfy that assumption because each cross-sectional image is obtained independently by the sonographer in an unguided manner.2 An external 3D spatial coordinate system provides a means of precisely measuring the relationship of one cross-sectional image with respect to another, a necessary prerequisite for accurate quantification of the left ventricle. An external 3D spatial coordinate system, while providing the ability to scan freely without constraints has limitations. Limitations of the freehand acoustical spatial locating system are that it requires a clear line of sight between the sound emitters and the overhead receivers. An electromagnetic spatial locating system may be limited by interference with the electromagnetic field by large ferromagnetic objects such as metal examination beds and other nearby metallic equipment that may degrade system accuracy.7 Another means of relating images to one another is by providing a spatial coordinate system that is internal to the heart. This approach is based on the principle that a 3D data set can be reconstructed from a series of 2D images in which the intervals and angles between the

C

Figs 54.2A to C: Freehand scanning. A modified ultrasound probe is tracked in three-dimensional (3D) space using an electromagnetic field device; images then may be reconstructed offline to create 3D data sets. A schematic of the receiver and transmitting device and the Cartesian coordinate system for tracking the location of the transducer is shown. (Courtesy of TomTec Imaging Systems, Munich, Germany; with permission).

Chapter 54: Three-Dimensional Echocardiographic Assessment of LV and RV Function

2D images are defined. In this method, serial 2D images are obtained using a mechanically driven transducer that sequentially recorded images at predefined intervals from a fixed transducer position. The images may be acquired in a parallel fashion or by pivoting around a fixed axis in a rotational, fan-like manner. A variety of transthoracic and transesophageal echocardiographic systems were devised in which fast rotating transducers provided a series of cross-sectional images that were all spaced relative to each other in precise fashion (Fig. 54.3).8–14

Limitations of 2D Echocardiography— Geometric Assumptions Since conventional echocardiography does not provide cross-sectional images that are spatially related to each other in a precise fashion, it is necessary to make certain assumptions about ventricular geometry to arrive at a more objective assessment of LV size and function. Linear measurements are popular and still reported today. However, they are difficult to reproduce when acquired in an unguided fashion and they assume that ventricular enlargement occurs uniformly and is reflected faithfully in the increase in the linear dimension. For example, when

1151

the ventricle enlarges along its superior–inferior axis, that increase is not reflected in the parasternal long-axis view from which LV dimensions are traditionally reported. To improve on simple linear dimensions, a plethora of models of ventricular size and shape have been devised. Popular among these is a prolate-ellipsoid model that utilizes two apical views (two-chamber and four-chamber). Here the ventricle is assumed to conform to the shape of a prolateellipse and ventricular volume is calculated based on traced endocardial borders from these views.15 However, when the ventricle is affected particularly by regional ischemic heart disease, the ventricle may enlarge and remodel in ways that deviate from a prolate-ellipsoid shape, thereby posing a severe limitation to accurate quantification of its size and function. 3DE overcomes these limitations by eliminating image positioning error and geometric assumptions (Figs 54.4 and 54.5B).16 3D reconstruction techniques have been used extensively in vivo to validate determination of LV volumes and EF against several reference clinical standards such as cardiac magnetic resonance imaging (CMR), cineventriculography, as well as multigated radionuclide scintigraphy using the transthoracic approach17–20 and shown to be superior to conventional 2DE methods.

Fig. 54.3: Schematic of how three-dimensional (3D) transesophageal echo (TEE) was acquired. The TEE probe is shown with its range of rotation from 180°. Typically, a two-dimensional (2D) image was acquired every 3°. The relationship between the heart and the TEE rotation is shown. (Courtesy of TomTec Imaging Systems, Munïch, Germany; with permission.)

1152


A

Fig. 54.4: Three-dimensional (3D) reconstruction—left ventricular volume can be computed using a polyhedral surface reconstruction algorithm from a series of images acquired from the base of the heart to the apex.

Limitations of 2D Echocardiography— Apical Foreshortening and Boundary Recognition 2DE from the transthoracic approach has additional limitations that are patient specific and inherent to the anatomy and position of the heart as it is situated in the rib cage. Imaging is performed through the interspaces between the ribs and even though guided 3DE can achieve perfect image positioning, image quality may be degraded if there is no optimal transthoracic interspace. Inherent ways of compensating for the lack of an adequate rib interspace is to utilize whatever echocardiographic window is available. This can frequently lead to apical foreshortening as was nicely demonstrated in a simultaneous echocardiographic and cineventriculographic study.21 Similarly, it is possible to obtain only tangential cross-sections of the heart that may cause inaccuracies in estimating linear dimensions and wall thickness.

Limitations of 3D Reconstruction Although 3D reconstruction addresses the principal limitations to accurate quantitation of the left ventricle, namely image position error and geometric assumptions, this methodology has several limitations. The images acquired for 3D reconstruction are nonsimultaneous. Therefore, it may be inaccurate in patients with significant intracardiac dyssynchrony. It also requires electrocardiogram (ECG) gating and is susceptible to inaccuracies due

B

Figs 54.5A and B: Field of view for two-dimensional (2D) echo and real time three-dimensional (3D) echo. (A) Tomographic image field of conventional linear phased-array transducer; (B) Matrix array transducer used to obtain pyramidal volumetric data set. Relation of image dissections is shown by orthogonal B-scans and cross-sectional C-scan.

to patient motion and respiration. Therefore, to obtain a good 3D data set free from reconstruction artifacts, data acquisition takes longer and can last up to 5 minutes depending on the quality of the 2D images, the patient’s heart rate, and respiratory pattern. In addition, 2D images need to be exported to offline workstations and reprocessed manually using proprietary software. The time taken to process the images depends on the size of the heart and the number of images required obtaining an accurate estimate of LV volume. The greater the number of images, the less data interpolation is required between images and the greater the accuracy of the method. However, the greater the number of images obtained, the greater the processing time. Typically, four to six images are required for accurate determination of LV end-diastolic and end-systolic volumes (ESVs).

Real Time 3DE Advances in transducer technology have experienced a revolution due to the increasing computing power of modern electronics as well as miniaturization. These developments allowed the first matrix array transducer to be constructed by von Ramm et al.22–24 Here the transducer elements are arranged in a grid that allows steering in both the azimuth and elevation directions as compared to a conventional transducer that allows steering only in the azimuth direction (Figs 54.5A and B). This seminal innovation with 16:1 parallel processing allowed imaging of a volume rather than a sector. Furthermore, real time


A

1153

B

Figs 54.6A and B: (A) First-generation matrix array transducer: Simultaneous display of parasternal long-axis (orthogonal B scan) and short-axis views (C-scan); (B) First-generation matrix array transducer: Simultaneous display of apical (orthogonal B scan) and shortaxis views (C-scan). (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

scanning could be performed in a single heartbeat that did not require ECG gating and allowed simultaneous display of the images derived from the 3D data set. This firstgeneration matrix array transducer operated at a frequency of 2.5 MHz and consisted of 256 nonsimultaneous firing elements that acquired a pyramidal volume data set measuring 60° × 60°. A limitation of this first-generation matrix array technology was that the image quality was relatively poor and did not match conventional 2D image quality. Additionally, since this was not a fully sampled matrix but a sparse-array matrix, it did not allow for 3D rendering, but did allow simultaneous orthogonal B-scans and cross-sectional C-scans to be displayed (Figs 54.6A and B). Furthermore, large hearts could not be imaged within the 60° × 60° volume. Nevertheless, it paved the way for further advances to be made in matrix array transducer technology and spurred many commercial ultrasound manufacturers to develop it further. Currently, real time 3DE (RT 3DE) is offered on several commercial platforms. RT 3DE can be performed by either switching among 2D and 3D transducers, or alternating between 2D and 3DE modalities present within the same all-in-one probe.25 3DE is the only imaging method that is able to view moving structures in the beating heart in real time. In contrast, cardiac computed tomography (CT) and magnetic resonance imaging (MRI) provide only 3D reconstructed images from multiple tomographic planes. In contrast to the first-generation matrix array transducers, current systems are fully sampled because they typically have over 3,000 elements that make up the grid that allows 360° focusing and steering and 3D rendering. Figures 54.7A and B contrast the size of the elements compared

to a human hair within a phased-array transducer compared to a matrix array transducer.26 Most matrix array transducers have technology that provides wider bandwidth with higher sensitivity. This technique now permits tracking of the endocardial borders in real time throughout the cardiac cycle. Whereas 3D reconstruction methods and first-generation matrix array transducers only permit calculation of static volumes at end-diastole and end-systole, current matrix array transducers allow us to tracking ventricular volume over the full cardiac cycle, thereby allowing us to not only calculate overall EF, which is a very important measure of cardiac performance, but also to calculate rates of ejection and rates of filling, which may be important as well. With further reduction in the size of electronics, 2D arrays can now be integrated into a volume that is small enough to fit on a transesophageal transducer probe, thus allowing for real time 3D scanning of the heart, thus avoiding image degradation from ribs, lungs, and fat. As ingenious as real time three-dimensional transesophageal echocardiography (RT 3DTEE) is, it has not yet been feasible to perform accurate measurement of volumes using this technique, primarily due to limitations of the sector size, frame rate, and finding suitable boundary tracking algorithms that will perform wall on this complex data set. Current RT 3DE systems offer several data acquisition modes that have varying sector sizes. Data acquisition is always a trade-off between sector (volume size), line density (spatial resolution), and volumes/second (temporal resolution). At present, two different methods for 3D data acquisition are available: “real time 3D” or “live 3D mode” and multibeat 3D mode. In the real time or live mode, a thin sector (typically 30° × 60°) of a

1154


A

B

Figs 54.7A and B: (A) Phased-array elements compared to the size of a human hair; (B) Matrix array elements compared to the size of a human hair.

Fig. 54.8: Full-volume three-dimensional (3D) data set acquired by a second generation matrix array transducer consisting of four stitched volumes acquired over four to six heart cycles. The left hand panel depicts static reference images with the intersecting lines showing the intersection of sagittal and coronal planes. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 54.9: Full-volume three-dimensional (3D) data set acquired by a second generation matrix array transducer consisting of four stitched volumes acquired over four to six heart cycles. The left hand panel depicts static reference images with the intersecting lines showing the intersection of sagittal, coronal and axial planes. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

pyramidal 3D data set is obtained and visualized live, beat after beat as during 2D scanning. In this mode, narrow volume, zoom, wide-angle, and color Doppler modalities are available. Since data acquisition in this mode is done in a single heartbeat, no ECG or respiratory gating is required and heart dynamics is shown with instantaneous online volume rendered reconstruction. This mode also overcomes limitations posed by rhythm disturbances and respiratory motion. However, this mode suffers from relatively poor spatial and temporal resolution.

To provide better spatial and temporal resolution, multibeat acquisitions can be performed to yield a fullvolume data set. Typically a full-volume data set in secondgeneration 3D echocardiographic systems comprises four of the small live sectors stitched together to provide a sector size that is much larger (e.g. 101° × 104° depending on the particular commercial system used and the transducer type). This technique is not real time and therefore requires ECG gating and is acquired over four to six consecutive heartbeats (Figs 54.8 and 54.9). The full-volume mode is


A

1155

B

Figs 54.10A and B: (A) Full-volume three-dimensional (3D) data set acquired by a third-generation matrix array transducer. The data set is displayed as a set of three image planes that are spaced 60° apart and one cross-sectional axial image; (B) Three equiangular planes (triplane) that are spaced 60° apart can be generated selectively instead of acquiring a full-volume data set and used for calculation of 3D volumes and ejection fraction. The image quality of triplane imaging is superior to that of full-volume imaging and therefore, may have some advantages for left ventricular quantitation.

prone to stitching artifacts if the patient moves or breathes deeply during image acquisition. However, it has the advantage of imaging a large volume while preserving high spatial and relatively good temporal resolution (volume rates). Stitching artifacts may be minimized by performing data acquisition during suspended respiration. Arrhythmias such as atrial fibrillation may also produce stitching artifacts when patients with this arrhythmia are imaged in the full-volume mode. Third-generation 3D echocardiographic systems have even higher processing power with fully sampled 2D matrix arrays such that a full-volume can be obtained in a single heartbeat (Movie clip 1A) with little sacrifice in image quality. A zoom mode is also typically provided. This is an enlargement of a subsegment of the thin slice live sector that is ~30° × 30° that provides even greater spatial and temporal resolution (Movie clip 1B). An x-plane mode allows simultaneous viewing of a cross-section and the plane orthogonal to it. Lateral tilting of this plane is also possible by manipulating the trackball (Movie clip 2). A mode that is particularly helpful with LV quantitation is the triplane mode. Figure 54.10A shows a full-volume data set that may be obtained for LV quantitation. In this mode, the left ventricle is tracked by a border-tracking algorithm using the full 3D data set for the full cardiac cycle. Using this feature, dynamic LV volumes may be obtained that are helpful in evaluating not only EF, but also intracardiac dyssynchrony, as well as ejection rates

and filling rates. However, if only 3D EF is desired, static volumes in end-diastole and end-systole are sufficient. In this case, simultaneous viewing of triplane images, which are derived from the same heartbeat and same 3D data set but have higher resolution than the full-volume data set, may be more practical (Fig. 54.10B and Movie clip 3). Triplane LVEF is computed from static volumes obtained at end-diastole and end-systole from three equidistant planes 60° apart. Even though the phantom appears as if it is contracting dynamically, the only true volumes that are obtained are from end-diastole and end-systole. Computer data interpolation is performed for all other points in the cardiac cycle (Movie clip 3). Triplane volumes tend to underestimate true volume since they are obtained only from three images. However, the EFs derived from them are quite reliable. A further advance in LV quantitation has been to provide automatic endocardial borders without the need for any manual operator interaction. These sophisticated systems were designed by feeding data generated from thousands of manually endocardial borders by experts and teaching the computer to recognize the type of echocardiographic view being presented and generating an automatic border based on recognizable features. Examples of apical two-chamber (Movie clip 4) and four-chamber views (Movie clip 5) being automatically processed and borders generated for EF calculation are shown. Current 3D echocardiographic systems also allow overlay of color information (Movie clip 6),

1156


conventional tissue Doppler information (Movie clip 7) as well as color-coded strain information (Movie clip 8) that are helpful for evaluating regurgitant jets, intracardiac dyssynchrony, and wall motion, respectively. For these purposes, the triplane mode is particularly helpful because of its higher temporal resolution than the single-beat fullvolume mode.

Validation Studies of Real Time 3DE for Left Ventricular Volumes and Ejection Fraction Extensive validation studies of RT 3DE against independent reference methods have been performed. Almost all of them confirm the earlier validation studies with 3D reconstruction against the same reference standards. Most show superiority over conventional 2D methods together with improved intraobserver, interobserver, and test– retest variability.27–34 Correlation coefficients against CMR for end-diastolic volumes (EDVs) have varied from 0.92 to 0.98, and for end-systole from 0.81 to 0.98. Variable systematic underestimation of 3D EDVs from 4 mL to 14 mL has been reported; underestimation of ESVs from 3 m L to 18 mL has also been reported. However, since both EDVs and ESVs are underestimated, EF calculations have been neither systematically overestimated nor underestimated. Interobserver variability varies from 5% to 11%. Whereas 3D reconstruction methods had longer acquisition times and image-processing times, RT 3DE has significantly cut down on data acquisition time in many cases, to a single heartbeat or four to six heartbeats. In addition, border tracking has been increasingly automated, requiring only specifying anatomic landmarks within the left ventricle (medial and lateral mitral annular points and the apex). While border tracking has made the reporting of ventricular volumes more practical, the best results are obtained only when image quality is good and when computer generated boundaries are manually corrected. The underestimation of ventricular volumes and sources of error have been studied extensively by several investigators. Using the several modes of 3D data acquisition as well as processing of 3D data, it is possible to analyze in detail the sources of error contributing to traditional underestimation of volumes by echocardiography. Image positioning error includes nonorthogonal image positioning as well as apical foreshortening. This type of error predominates in normally shaped ventricles. It can be minimized by aligning apical images in such a way that

the long axis of the ventricle is maximized before manual boundary tracing or border tracking is applied. However, in patients with abnormal ventricles, the predominant source of error is due to geometric assumptions that may not be valid.35 This source of error can be minimized by increasing the number of images utilized for sampling the ventricle and carefully editing computer-generated endocardial boundary. However, despite controlling for image positioning error and geometric assumption error, underestimation is still present due to differences in boundary tracing depending on the modality chosen as the reference modality.35 This finding was confirmed by a multicenter study36 as well as by a recent meta-analysis of 23 studies (1,638 echocardiograms) that compared LV volumes and EF measured by RT 3DE and CMR examined the overall accuracy of RT 3DE. A subset of those also compared standard 2D methods with CMR. The pooled biases ± 2 SDs for 3DE were –19.1 ± 34.2 mL, –10.1 ± 29.7 mL, and –0.6 ± 11.8% for EDV, ESV, and EF, respectively. Nine studies also included data from 2DE, where the pooled biases were –48.2 ± 55.9 mL, –27.7 ± 45.7 mL, and 0.1 ± 13.9% for EDV, ESV, and EF, respectively. In this subset, the difference in bias between 3DE and 2D volumes was statistically significant (p = 0.01 for both EDV and ESV). The difference in variance was statistically significant (p < 0.001) for all three measurements.37 Boundary-tracing error depends largely on image quality38 and differences in image segmentation, particularly with respect to the handling of papillary muscles and trabeculae. In CMR methods, these tend to be included in the cavity volume to a greater extent, thereby resulting in larger volumes. The larger the ventricle, the greater is the degree of underestimation.35 The underestimation of 3DE volumes is particularly noteworthy in subjects with heart failure. Compared to CMR, RT 3DE is accurate for evaluation of EF and feasible in heart failure patients, at the expense of a significant underestimation of LV volumes, particularly when LVEDV is above 120 mL/m2.39 Fully automated endocardial trabecular contouring algorithms have also been used and validated to compute volumes and EF and compared to CMR in patients in sinus rhythm (67 subjects) as well as in atrial fibrillation (24 subjects). To correct for the underestimation of volumes, an automated correction can be applied to track the compacted myocardium. Among all sinus rhythm patients, there was excellent correlation between RT 3DE and CMR for EDV, ESV and EF (r = 0.90, 0.96, and 0.98, respectively; p < 0.001). In patients with EF ≥ 50% (n =36), EDV and ESV were underestimated by 10.7 ± 17.5 mL (p = 0.001) and by


4.1 ± 6.1 mL (p < 0.001), respectively. In those with EF < 50% (n = 31), EDV and ESV were underestimated by 25.7 ± 32.7 mL (p < 0.001) and by 16.2 ± 24.0 mL (p = 0.001). Automated contour correction to track the compacted myocardium eliminated mean volume differences between RT 3DE and CMR. In patients with atrial fibrillation, LV volumes and EF were accurate by RT 3DE (r = 0.94, 0.94, and 0.91 for EDV, ESV, and EF, respectively; p < 0.001). Automated 3D LV volumes and EF were highly reproducible, as expected.40 Newer ways of addressing the systematic underestimation of RT 3DE volumes compared to CMR have utilized contrast agents. The use of contrast agents may improve endocardial border recognition in RT 3DE. However, automatic and semi-automated border-tracking algorithms for calculation of RT 3DE ventricular volumes have not been rigorously developed for use with contrast agents. In addition, contrast agents can sometimes cause attenuation and difficulty in identifying the valve planes, which may result in variable inclusion or exclusion of the left atrium. An approach that shows some promise, particularly in patients with poor acoustic windows, is the use of contrast agents in conjunction with power modulation (PM) imaging that uses low mechanical indices and provides uniform LV opacification.41

Normal RT 3DE Values for Volumes and Ejection Fraction Practical and routine clinical use of 3DE volumes and EF to detect LV remodeling and dysfunction require agespecific and gender-specific reference ranges. In 226 consecutive healthy Caucasian subjects (125 women; age range, 18–76 years), comprehensive 3DE analyses of LV parameters were performed, and values were compared with those obtained by conventional echocardiography. Upper reference values (mean + 2 SDs) for 3DE LV EDVs and ESVs were 85 and 34 mL/m2 in men and 72 and 28 mL/m2 in women, respectively. Indexing LV volumes to body surface area did not eliminate gender differences. Lower reference values (mean –2 SDs) for EF were 54% in men and 57% in women and for stroke volume were 25 and 24 mL/m2, respectively. Upper reference values for LV mass were 97 g/m2 in men and 90 g/m2 in women and for end-diastolic sphericity index were 0.49 and 0.48, respectively. Significant age dependency of LV parameters was identified and reported across age groups. 3D echocardiographic LV volumes were larger, EF was similar and LV stroke volume and mass were significantly smaller

1157

in comparison with the corresponding values obtained by conventional echocardiography.42 In addition to gender- and age-specific reference values, population-specific reference values may also be important. A study of 978 subjects from the London Life Sciences Prospective Population (LOLIPOP) study, who were free of clinical cardiovascular disease, hypertension, and type 2 diabetes, showed that indexed 3DE LV volumes were significantly smaller in female as compared with male subjects and in Indian Asians compared with European whites. Upper limit of normal (mean ± 2 SD) reference values for the LVESV index and LVEDV index for the four ethnicity–sex subgroups were, respectively, as follows: European white men, 29 and 67 mL/m2; Indian Asian men, 26 mL/m2 and 59 mL/m2; European white women, 24 mL/m2 and 58 mL/m2; Indian Asian women, 23 mL/m2 and 55 mL/m2, respectively. Compared with 3DE studies, 2DE underestimated the LVESV index and LVEDV index by an average of 2.0 and 4.7 mL/m2, respectively. LVEF was similar between in all four groups and between 2D and 3D techniques, with a lower cutoff of 52% for the whole cohort.43

New 3DE Parameters and RT 3DE Left Ventricular Strain The ability to generate time–volume curves from dynamic RT 3DE volumes throughout the cardiac cycle have generated new 3DE parameters of LV diastolic and systolic performance that have shown interesting results in small pilot studies. These parameters may be particularly helpful in the detection of ischemia since diastolic LV abnormalities are sensitive early signs of myocardial ischemia and persist longer than systolic changes.44,45 Abnormalities of peak filling rate (PFR), expressed in units of EDV/s, have been reported in ischemic patients using Doppler echocardiography.46 A pilot study by Gopal et al. used RT 3DE to evaluate PFR in 19 subjects with an intermediate-high risk of computer-aided design (CAD) together with 1-day rest/stress adenosine 99mTc-sestamibi gated single-photon computed emission tomography (GSPECT). Adenosine was infused at 140 mcg/kg/min over 6 minutes. Nuclear images were acquired at 16 frames/R-R interval for 64 projections over a 180 arc at rest and poststress. 2DE and RT 3DE were performed at rest and at peak stress (at 2–6 minutes of adenosine infusion). GSPECT and RT 3DE data were analyzed by QGS (Cedars-Sinai) and QLab (Philips) algorithms, respectively.

1158


Fig. 54.11: Peak filling rate (PFR) derived from RT 3DE time volume curves fitted to third order harmonics normal response-rest and stress. (RT 3DE: Real time, three-dimensional echocardiography).

Fig. 54.12: Peak filling rate (PFR) derived from RT 3DE time volume curves fitted to third order harmonics-ischemic response-rest and stress. (RT 3DE: Real time, three-dimensional echocardiography).

Nuclear and RT 3DE volume versus time curves were Fourier-fit to third-order harmonics to compute PFR by custom software (RSI, Inc., Boulder, CO) for rest and stress. PFR difference (PFRΔ) was defined as PFR stress– PFR rest. Nuclear perfusion defects were quantified by 17-segment/5-point stress and rest nuclear perfusion scores and a summed difference score (SDS) > 2 accepted as abnormal and indicative of stress-induced ischemia.47 A qualitative assessment of rest and stress wall motion scores (WMS) were determined for 17 segments and 2DE WMS difference (WMSΔ) were computed as follows based on systolic wall thickening48: normal wall thickening was given a score of 1; hypokinetic wall = 2; akinetic was scored = 3; and dyskinetic = 4. The mean age of the study group was 68.4 ± 15 years, with 14 males. There were no significant differences in the change in heart rate between rest and adenosine stress studies for patients with ischemia versus patients without ischemia (heart rate change of 17 ± 12 beats/min vs 13 ± 8 beats/min, p = 0.15). Of all the echo parameters examined, only PFRΔ exhibited significant associations with ischemia. The response to adenosine stress in patients without ischemia was an increase or no change in PFR (Fig. 54.11). An abnormal response to adenosine stress was a decrease in PFR (Fig. 54.12).

Figure 54.13 shows a representative patient with lateral perfusion defect whose 2DE WMSΔ was normal but whose PFRΔ was abnormal. Of the six patients with ischemia (SDS > 2), four patients had abnormal PFRΔ compared to those without ischemia (–0.12 ± 0.77 EDV/s vs +0.66 ± 0.44 EDV/s, p = 0.02); two patients had both a normal WMSΔ and a normal PFRΔ. Two of the four patients with abnormal PFRΔ also had an abnormal WMSΔ (Table 54.1). PFRΔ correlated inversely with ischemia [Spearman’s coefficient = –0.55, p = 0.03 with 95% confidence interval (CI) = −0.81 to −0.08, Fisher exact test, p = 0.006; Fig. 54.14]. An abnormal PFRΔ predicted myocardial ischemia with 89% accuracy, 100% specificity, 66% sensitivity, 100% positive predictive value, and 86% negative predictive (ROC PFRΔ threshold > 0.0). In addition to being able to assess ejection rates and filling rates, LV performance may be assessed by 3D strain analysis. Strain analysis can be performed by a technique known as STE, which identifies a pattern of speckles in one frame and then tries to find the same pattern in the following frames using pattern-matching algorithms. This allows all anatomic features including the myocardium present in the echocardiographic image to be tracked through space and time. This technique offers advantages


1159

Table 54.1: Comparison of mean PFR to SDS >2.

Myocardial ischemia

Stress-rest differences PFR  > 0

PFR  < 0

SDS < 2

13

0

SDS > 2

2

4

Fig. 54.13: Lateral wall ischemia-adenosine 99mTc-Sestamibi GSPECT. GSPECT, gated single-photon computed emission tomography. Fig. 54.14: Comparison of mean PFR to SDS >2. Mean values and error bars representing one standard deviation is plotted.

Fig. 54.15: One-dimensional Lagrangian strain. The length is the only strain component, and thus L is measured along the only coordinate axis, thus L = x. Source: Reproduced with permission from: http://folk.ntnu.no/ stoylen/strainrate).

over tissue Doppler imaging (TDI), which also measures myocardial motion, but which is angle dependent. Therefore, motion that occurs along the ultrasound beam can be detected by TDI. However, motion that occurs perpendicular to the ultrasound beam is not detected. This limitation is overcome by STE. Myocardial motion can be expressed as myocardial displacement, velocity, or strain. However, the former two are affected by cardiac translation that may occur with each heartbeat or with respiration. Strain, however, measures the deformation of the myocardial muscle as the difference between its length at a certain point in the cardiac cycle and its initial length divided by its initial length. Thus, contraction is expressed as a negative strain value whereas elongation is expressed as a positive strain value. Limitations of 2D STE include difficulties tracking the speckles when the speckles move

in and out of the 2D imaging plane. To overcome this limitation, 3D STE has been developed. Thus, displacement measured by 3D STE is larger than the corresponding 2D STE values, indicating that through-plane motion (motion perpendicular to the imaging plane) can be detected by 3D STE but not 2D STE.49 Myocardial contractile motion is complex and 3D. In addition, the complex arrangement of muscle fibers contributes to varying extents to myocardial deformation. Strain analysis is usually performed by using an external Cartesian spatial coordinate system. 1D strain occurs only along the coordinate axis (Fig. 54.15). In 2D, the strain tensor has four components, two along the coordinate axis and two shear strains (Fig. 54.16). In 3D, the complex 3D myocardial deformation can be decomposed into three normal and six shear strains (Fig. 54.17). Normal strains (longitudinal, circumferential, and radial) reflect changes in length along a spatial coordinate system.50 Shear strains (longitudinal–radial, circumferential–radial and circumferential–longitudinal) are forces acting in opposite directions.50 Myocardial strain can be described without an external spatial coordinate system using three principal strains and three principal angles or axes of deformation that form an internal frame of reference.50 The

1160


Fig. 54.16: Strain in two dimensions. Above are the two normal strains along the x and y axes, where each strain component can be seen as Lagrangian strain along one main axis. Below are the two shear strain components, movement of the borders relative to each other. Here there are two strain components, characterized by the tangent to the shear angle alpha. Source: Reproduced with permission from http://folk.ntnu.no/ stoylen/strainrate.

Fig. 54.17: Strain in three dimensions. Only the three strain components along the x axis (one normal, two shear) are shown, but the y and z strains will be exactly the same and can be imagined by rotating the x images. Source: Reproduced with permission from: http://folk.ntnu.no/stoylen/strainrate.

three principal strains are oriented along three mutually orthogonal directions and ranked from maximum contraction at the end of systole to maximum lengthening at the end of diastole.50,51 The principal strain is the maximum contraction that occurs in an oblique direction within the circumferential–longitudinal plane and angled to spiral counterclockwise from the apex to base (as viewed from the apex).51 It aligns in the general direction of the subepicardial muscle fibers.52 The benefit of this approach of describing myocardial strain along the axes of deformation (internal frame of reference) rather than in terms of an external Cartesian spatial coordinate system is that it can provide a more integrated perspective of all the major forces experienced at the tissue level. In addition, an internal frame of reference allows us to eliminate shear strain since principal strain represents the combined effect of shortening and shear.53 Rotation and

translation of the heart are no longer important with this internal frame of reference approach53 (Fig. 54.18). As described above, 3D STE offers an integrated approach toward analyzing the complex motion of the heart. In addition to providing more accurate and reproducible volumes compared to 2D STE,54 it provides a new methodology for analyzing regional function. 3D STE shows that all strain components are reduced in abnormal regional segments.49 3D STE also provides new 3D parameters to assess LV systolic function such as global area strain (percentage of deformation in the LV endocardial surface area defined by the longitudinal and circumferential strains vectors). Recent studies have shown that this parameter is more accurate and reproducible on a regional level than the other components.55 Global area strain is strongly correlated with LVEF and to a lesser degree with cardiac output.56


Fig. 54.18: In the heart, the usual directions are longitudinal, transmural (radial), and circumferential as shown to the left. In systole, there is longitudinal shortening, transmural (radial) thickening and circumferential shortening. (This is an orthogonal coordinate system, but the directions of the axes are tangential to the myocardium, and thus changes from point to point). Source: Reproduced with permission from: http://folk.ntnu.no/ stoylen/strainrate.

A progressive decrease in global area strain is noted as heart failure progresses from normal to stage D.57 A study that compared a 3D strain vector (summing the radial, circumferential and longitudinal vectors) and 3D area strain in patients with coronary artery disease showed that while area strain correlated with the severity of transmural extent of necrosis, 3D strain decreased only when necrosis extent was > 75%.58 Though many of these alternative approaches of quantifying LV performance appear promising, it is unclear how these indexes will correlate diagnostically or prognostically given such constraints as vendor variability and proprietary algorithm differences, a sentiment reflected by a recent consensus statement by the American and European Societies of Echocardiography.59

Left Ventricular Mass by 3DE Several studies, including the Framingham Heart Study, have demonstrated that elevated LV mass is an independent and strong predictor of morbid cardiac events and death.60 Conventional 1D M-mode echo and 2DE methods of measuring mass rely on geometric assumptions, lack spatial registration and are associated with comparatively high measurement variability, particularly in abnormally shaped hearts.61 As a consequence, the test–retest stability of 1D and 2DE for the serial measurement of LV mass in patients with hypertension may be impaired. Gottdiener

1161

Fig. 54.19: Three-dimensional (3D) line of intersection display positioned short-axis images for left ventricular (LV) mass computation. Traced epicardial and endocardial borders are shown.

et al.62 showed that the 95% CI width of a single replicate measurement of LV mass was 59 g. This measurement variability exceeds the usual decrease in mass during treatment.62 Alternative imaging tools such as MRI and ultrafast CT not only use nonportable equipment but also are expensive, cumbersome and not widely available for serially following LV mass in patients. LV mass has been calculated by 3DE reconstruction by subtracting the endocardial volume from that of the epicardium and multiplying the result by 1.05, the density of myocardium (Fig. 54.19). It was calculated in vitro in fixed animal hearts very accurately with a standard error of the estimate (SEE) of 2–3 g.63 Anatomic in vivo animal validation provided the best results for 3D echo reconstruction (r = 0.96, SEE = 5.9 g, accuracy 6.8%) compared with the truncated ellipsoid (r = 0.88, SEE = 10.2 g, accuracy 12.6%) and bullet (r = 0.83, SEE = 12 g, accuracy = 12.7%) algorithms.63 In vivo validation of LV mass by 3DE reconstruction was carried out in normal subjects using MRI as a standard of comparison and was shown to correlate highly (r = 0.93, SEE = 9.2 g) with good interobserver variability (6.3%) and statistically no different from corresponding MRI values.64 In the same population, 3DE reconstruction achieved a two- to threefold improvement in the correlation with MRI over conventional M-mode and 2DE algorithms used to compute LV mass.64 In patients with abnormal ventricular geometry, the SEE and limits of agreement between 3DE reconstruction and MRI were roughly twice the values found in normal subjects.18 LV mass determination by 3DE reconstruction

1162


has also been anatomically validated in vivo in humans undergoing heart transplantation using the true weight of the left ventricle of the explanted hearts (range 125–433 g) as the standard of reference and compared to M-mode Penn, 2DE area length and truncated ellipsoid algorithms. The results showed that 3DE reconstruction is a highly accurate and reproducible method (r = 0.993, accuracy = 4.6%, bias = −3.4 g, and interobserver variability 9.4%). In addition, 3DE reconstruction accuracy was fourfold superior to 2DE (r = 0.898, accuracy 19.2%, bias +21.7 g, interobserver variability 16.7%) and ninefold superior to M-mode echocardiography (r = 0.817, accuracy 43.4%, bias +85.1 g, interobserver variability 18.2%).65 Studies of LV mass with 3DE reconstruction showed that conventional M-mode calculations of LV mass significantly overestimate true mass. RT 3DE has also been used to calculate the feasibility of calculating LV mass. While 3DE reconstruction utilized parasternal short-axis images for tracing epicardial and endocardial borders, the RT 3DE utilizes apical views. The use of apical views for tracing epicardial and endocardial borders presents two problems: apical foreshortening and off-axis longitudinal views. The first problem results in underestimation of LV mass that may be reduced by using a 3D-guided biplane technique.66 The second problem occurs when the imaging plane does not pass through the center of the left ventricle along its longitudinal axis. This can result in tangential views of the myocardium that show an artificially thick ventricle and may overestimate mass. RT 3DE imaging with single-beat capture has been used to validate LV mass measurements in 69 patients with hypertrophic cardiomyopathy against a CMR reference standard. RTDE and CMR values were also compared to M-mode mass and the 2D-based truncated ellipsoid mass. The mean time for RT 3DE analysis was 5.85 ± 1.81 minutes. Intraclass correlation analysis showed a close relationship between RT 3DE and CMR LV mass (r = 0.86, p < 0.0001). However, LV mass by the M-mode or 2DE method showed a smaller intraclass correlation coefficient compared with CMR-determined mass (r = 0.48, p = 0.01, and r = 0.71, p < 0.001, respectively). Bland–Altman analysis showed reasonable limits of agreement between LV mass by RT 3DE and by CMR, with a smaller positive bias [19.5 g (9.1%)] compared to that by the M-mode and 2D methods [−35.1 g (−20.2%) and 30.6 g (17.6%), respectively]. These results confirm the finding by 3DE reconstruction that conventional LV mass algorithms tend to overestimate LV mass.67 Although 3DE has shown to be more accurate than M-mode and 2DE, a meta-analysis of 25 studies including

671 comparisons were analyzed showed that 3DE still underestimated LV mass compared to CMR. However, the underestimation improved with time from −5.7 g, 95% CI −11.3 to −0.2, p = 0.04 in studies before 2004 to −0.1 g, 95% CI −2.2 to 1.9, p = 0.90 in studies published after 2008.68

Left Ventricular Remodeling, Sphericity, and Regional Function by 3DE 3DE reconstruction has been used to analyze LV endocardial surface area, infarct subtended surface area, infarct subtended volume and volume/mass ratio, which may be measures that supplement measures of LV mass in studying LV remodeling.69–72 In addition, LV shape can be characterized in terms of a sphericity index. This is done by calculating a 3D surface area/volume ratio and indexing it to a surface area/volume ratio of a sphere. As the LV becomes more globular and spherical (i.e. undergoes adverse LV remodeling), its sphericity index approaches.1,73 LV volume can be further broken down into 16 or 17 regional segments and volume in each of these segments can be tracked over the full cardiac cycle to generate time– volume curves (Fig. 54.20). In a normal subject without significant intracardiac dyssynchrony, the minima of

Fig. 54.20: The left ventricle (LV) has been subdivided into 17 regional segments. The time–volume curve for each segment is displayed. In this normal subject without significant intracardiac dyssynchrony, the minima of the time–volume curves (shown on the top panel) and their first derivatives (bottom panel) are all reached at roughly the same time.


Fig. 54.21: The left ventricle has been subdivided into 17 regional segments. The time-volume curve for each segment is displayed. In this patient with significant intracardiac dyssynchrony, the minima of the time–volume curves (shown on the top panel) and their first derivatives (bottom panel) have a wide temporal dispersion.

Fig. 54.23: Time–volume curves are generated from the entire surface of the left ventricle (LV) and are color-coded in such a manner that late contracting segments are color-coded in shades of red and normally contracting segments are color-coded blue. This is a patient with significant intracardiac dyssynchrony with large areas of late contracting segments (shown in red).

the time–volume curves and their first derivatives are all reached at roughly the same time. However, in a patient with significant intracardiac dyssynchrony there is usually widening of the QRS interval together with a temporal dispersion of the time–volume curves (Fig. 54.21). Instead of breaking the LV down only into 17 regional segments, a bull’s-eye plot can be made of time–volume curves that

1163

Fig. 54.22: Time–volume curves are generated from the entire surface of the left ventricle (LV) and are color-coded in such a manner that late contracting segments are color-coded in shades of red and normally contracting segments are color-coded blue. This is a normal subject without dyssynchrony (no red areas are noted). (LA: Left atrium).

are generated from the entire LV surface. These time– volume curves can be color-coded in such a manner as to shown late contracting segments as shades of red and normally contracting segments in blue. A normal subject with a perfectly synchronous heart is shown in Figure 54.22. A patient with significant dyssynchrony is shown in Figure 54.23 with large areas of late contracting segments (shown in red). After receiving a biventricular pacemaker, the areas of late contracting segments (shown in red) have reduced in size (Fig. 54.24). Though these tools may be very helpful in evaluating a patient for a biventricular pacemaker, the reliability of the time–volume curves depends critically on the 3DE image quality. In addition, when regional volumes measured in a group of patients were compared against CMR as a reference, the levels of agreement were very high in basal and midventricular segments, but were considerably lower near the apex. This difference could probably be explained by the limited endocardial definition near the apex on both 3DE and short-axis CMR images that are affected by partial volume artifacts at this level.74 RT 3DE also provides new ways of assessing regional LV wall motion that may have implications for interpreting stress echocardiograms. Instead of viewing the left ventricle in conventional short axis, and apical images that only display a limited portion of the myocardium, RT 3DE can display the entire myocardial volume in a multislice panel, allowing a comprehensive assessment of regional wall motion (Movie clip 9).

1164


Fig. 54.24: Time–volume curves are generated from the entire surface of the left ventricle (LV) and are color-coded in such a manner that late contracting segments are color-coded in shades of red and normally contracting segments are color-coded blue. This is the same patient after receiving a biventricular pacemaker. Note that the areas of late contracting segments (shown in red) have reduced in size.

Fig. 54.26: Three-dimensional echocardiography (3DE) detected a statistically significant decrease in LV mass at both 6 weeks and 12 weeks whereas M-mode echocardiography showed a statistically significant decrease in LV mass only after 12 weeks of treatment. (LV: Left ventricle).

Serial Evaluation of Patients with 3DE The utility of a test to assess a parameter in a serial fashion is measured by its test–retest variability. It is well known that the test–retest variability of 3DE is lower than that of 2DE. For example, test–retest variability studies of 3DE LV mass have shown that 95% of the time, a change of

Fig. 54.25: Three-dimensional (3D) echo detected a statistically significant decrease in LV mass which paralleled a decline in BP. (BP: Blood pressure; LV: Left ventricle).

25.8 g or greater is considered significant, that is, not due to measurement variability alone. This is a greater than twofold improvement over the value of 59 g reported by Gottdiener et al. for the conventional M-mode method. The importance of greater accuracy and reproducibility of 3D echo in detecting biologically significant LV mass regression is illustrated in a preliminary study of patients with hypertension and LV hypertrophy that were treated and imaged at baseline, after 6 weeks, and after 12 weeks of antihypertensive therapy. Under the conditions of this study, 3D echo detected a statistically significant decrease in LV mass at both 6 and 12 weeks owing to its lower measurement variability (narrower CIs) whereas M-mode echocardiography showed a statistically significant decrease in LV mass only after 12 weeks of treatment (Figs 54.25 and 54.26). Using the standard deviation (SD) of the decrease in LV mass at the end of 12 weeks by each method, it was calculated that 3D echo was capable of detecting a 10 g reduction in LV mass at a power of 80% with one-third the number of patients (n = 42) compared with M-mode echocardiography (n = 148 patients; Fig. 54.27). In addition, owing to the low intraobserver variability of 3DE, 85% of the measured change in LV mass could be attributed to true biologic change. In contrast, since the intraobserver variability of M-mode echocardiography exceeded the measured change in mass, the contribution due to true biologic change could not be determined.75 Sequential quantification of LVEF and volumes in patients undergoing cancer chemotherapy are important to clinical decision making. Marwick and colleagues


1165

Table 54.2: Misclassification rate of EF postmyocardial infarction (comparison of clinical EF, 2DE EF, and 3DE EF to CMREF)

25%

CMR EF = 40%

CMR EF = 30%

Clinical EF

42.4%

15.2%

2DE EF

21.8%

10.9%

3DE EF

14.5%

5.4%

(EF: Ejection fraction)

studied the method for EF measurement with the lowest temporal variability. Fifty-six patients were selected for stable function in the face of chemotherapy for breast cancer by defining stability of global longitudinal strain (GLS) at up to five time points (baseline, 3, 6, 9, and 12 months). In this way, changes in EF were considered to reflect temporal variability of measurements rather than cardiotoxicity. 2DE-biplane, 2D-triplane, and 3DE acquisitions with and without contrast administration was performed at each time point. Stable LV function was defined as normal GLS (≤ −16.0%) at each examination. The best temporal variability of EF 0.06 was shown by noncontrast 3DE while other 2DE methods showed a temporal variability of > 0.10 with 2D methods over 1 year of follow-up.76

RT 3DE for Postmyocardial Infarct Risk Stratification Perhaps the greatest utility of 3DE LV quantification occurs in risk stratifying patients with heart failure or moderate LV dysfunction postmyocardial infarction (postMI). Decisions are made regarding offering lifesaving therapies such as implantable defibrillator placement and/or biventricular pacemaker based on the assessment of the EF post-MI. Risk stratification by routine methods (2DE, planar multigated radionuclide angiography, and cineventriculography) were compared to 3DE and CMR in 55 patients with MI or congestive heart failure and EF ≤ 40%. Patients were stratified by CMREF into two groups: EF ≤ 30% and ≤ 40%. For CMREF ≤ 30%, the misclassification rates were: 42%, 22%, and 14.5% by routine methods, 2D, and 3DE; for CMREF ≤ 40%, misclassification occurred in 15%, 11%, and 5% by routine methods, 2DE and 3DE. Regardless of the cutoff level chosen, 3DE had the lowest misclassification rate. 3DE also had a stronger correlation and less bias than 2DE (Table 54.2). 3DE but not 2DE was equivalent to CMR by analysis of variance (ANOVA). Test– retest variability of 3DE was threefold lower than 2DE. This study shows inadequacy of routine methods and the

Fig. 54.27: Using the standard deviation of the decrease in LV mass at the end of 12 weeks by each method, it was calculated that three-dimensional (3D) echo was capable of detecting a 10 g reduction in LV mass at a power of 80% with one-third the number of patients (n = 42) compared with M-mode echocardiography (n = 148 patients).

superiority of 3DE for risk stratification by EF post-MI. The reduced test–retest variability of 3DE compared to 2DE establishes its utility for serial monitoring.77

3D QUANTITATION OF THE RIGHT VENTRICLE Anatomic Considerations and Prior Conventional Approaches Accurate estimation of RV size and function is essential for the management of many cardiac disorders. Estimation of RV size and function is of central importance for the management of various congenital diseases.78 Echocardiographic variables that reflect the severity of right heart failure in primary pulmonary hypertension (PH) may help identify patients appropriate for more intensive therapy or earlier transplantation.79 Assessment of RV function is also important in determining treatment options for patients with pulmonary embolism, MI, and heart failure.80,81 Therefore, an accurate, easily repeated, noninvasive method would be ideal for the serial evaluation of patients. However, evaluation of RV function has been hampered by its complex crescentic shape, large infundibulum, and trabecular nature. Its function by invasive angiography can be characterized using area and length

1166


Fig. 54.28: Two-dimensional echocardiography (2DE) long-axis of RV (length) in diastole for purposes of RV volume calculation by the area-length method. (RV: Right ventricle).

Fig. 54.29: Two-dimensional echocardiography (2DE) short-axis of RV infundibular area in diastole for purposes of RV volume calculation by the area-length method. (RV: Right ventricle).

measurements or Simpson’s rule from single or biplane projections.82 Single plane methods provide limited sampling of the RV, depend on the orientation of the imaging planes with respect to intrinsic RV axes, and make shape assumptions. Biplane methods provide better sampling, but are invasive and often overestimate volume. While radionuclide ventriculography is not constrained by geometric assumptions, results have been variable and scanning requires the injection of radioactive agents.83 The retrosternal location of the RV as well as the presence of ribs makes it difficult to access this chamber fully by transthoracic echocardiography. Therefore, individual aspects of its function can be assessed separately. Transverse shortening can be assessed by fractional area change (FAC) in each short-axis slice. Longitudinal contraction can be assessed by tricuspid annular plane systolic excursion (TAPSE). TAPSE is measured as the distance in the four-chamber plane between the lateral aspect of the tricuspid annulus at end-diastole and endsystole. A TAPSE value of > 20 mm has been reported to be normal. Global function is assessed by calculation of right ventricular ejection fraction (RVEF) and several efforts have been made to find echocardiographic methods based on simple geometric models using single plane, biplane, or on multiplane methods based on Simpson’s rule.84–93 The most common method utilizes the area and length from an apical four-chamber view and an RV outflow tract view93 (Figs 54.28 and 54.29). The two views are assumed

to have an orthogonal relationship to each other. However, the transducer is moved from one position to another based on the sonographer’s knowledge of cardiac anatomy and orthogonality is assumed but not verified and rarely satisfied. Furthermore, a prolate-ellipsoid shape assumption is made, which also may not accurately depict RV anatomy. While area-length methods work in vitro and in animal models, they have wide confidence limits in human subjects when compared to methods, which are not subject to geometric assumptions.94 Moreover, the geometric models used to describe the shape of the RV can be changed unpredictably by disease. Wide confidence limits also occur due to reliance on anatomic visual information alone for determining image plane orientation. Previous experience with freehand 3DE reconstruction has shown wide operator variability in the optimal positioning of short-axis and apical image planes.2 In addition, apical views are often foreshortened during 2DE scanning, resulting in underestimation of the RV length that is used in area–length formulas.21 Sheehan et al. found that standard 2DE monoplane and biplane RV algorithms performed better when the images were positioned correctly using 3D electromagnetic guidance.95 Techniques such as the CT96 and CMR overcome limitations posed by other methods in that image planes are precisely defined and geometric assumptions are unnecessary.97 However, these imaging modalities are expensive and are not widespread.


1167

Previous 3D Reconstruction Approaches A variety of options for rapid 3DE image acquisition and reconstruction of the right ventricle have been used.98–111 Early approaches to 3DE reconstruction occurred from fixed transducer positions (apical or subcostal) and used rotational or “fan-like” scanning. This approach works if the patients are prescreened for good image quality, a prerequisite for this approach. However, a failure rate of 18% has been reported in postoperative subjects due to poor transthoracic windows.112 Therefore, 3DE reconstruction from a fixed transducer position provides mechanical 3D spatial registration of cross-sectional images, but is feasible only in those subjects who are echogenic enough to permit complete visualization of the right ventricle from a single echocardiographic position. Acoustic and electromagnetic tracking devices were developed to provide 3D spatial registration while scanning in a freehand fashion, permitting the sonographer to utilize all available echocardiographic windows.95,101,113 Apfel et al. studied 26 patients with PH with an acoustic spatial locating system and found a good correlation to spin-echo CMR but with 31–33% volume underestimation by 3DE.101 Since data acquisition occurs over several cardiac cycles in the span of 8–10 minutes, respiratory, whole body, or transducer motion will lead to data misregistration.

RT 3DE Approach to RV Quantification RT 3DE uses matrix array transducer technology, pioneered by von Ramm et al. and permits continuous acquisition of volumetric data, thereby allowing rapid scanning and minimizing the chance of motion artifacts. Cardiac motion can be evaluated in a dynamic mode and the heart can be viewed from any desired plane. Ota et al. validated RV volume measurements using a first-generation RT 3DE system in excised canine hearts and in 14 normal subjects. Though their method performed accurately in vitro, their in vivo standard of comparison was not a 3D method but a 2D monoplanar modified Simpson’s method. A good correlation and interobserver variability (8.3−9.4%) was noted between 3D right ventricular stroke volume (RVSV) and monoplanar 2DSV.114 Shiota et al. validated the same technology in sheep using electromagnetic flow probes. The correlation obtained for RVSV was r = 0.8 and the Bland–Altman analysis showed a mean RVSV difference of –2.7 mL.106 First-generation RT 3DE systems use a sparse array matrix transducer, which utilizes 256 nonsimultaneously firing elements to acquire a narrow

Fig. 54.30: Real time, three-dimensional echocardiography (RT 3DE) data acquisition from an off-axis apical window. The top left, top right and bottom left panels show three orthogonal multiplanar reconstructions (MPRs) of the RV. The bottom right panel shows a partial coronal view of the three-dimensional (3D) data set showing the intersecting sagittal and axial planes from which the MPRs were derived. (RV: Right ventricle).

sector angle (60°× 60°) pyramidal data set. While the 3D data set can be captured in one heartbeat, frame rates are low and image quality is relatively poor. Due to the narrow sector angle, visualization of the right ventricle is difficult since a large portion of it lies in the near field where the sector is narrowest. Second-generation RT 3DE systems use fully sampled matrix array transducers utilizing 3,000 elements. This results in improved image quality, greater contrast resolution, higher sensitivity, and penetration as well as capabilities for harmonic imaging. The full volume of the heart can be obtained by assembling four wedges of 15°× 60° each over eight consecutive cardiac cycles to obtain a pyramidal sector 90°× 90°. Some approaches have utilized an off-axis apical four-chamber view that highlights the right ventricle as the initial view taken for the acquisition of the RT 3DE data set (Fig. 54.30). Disc summation and apical rotation algorithms have been developed to quantify RV size and function in connection with RT 3DE. The RT 3DE-disc summation algorithm appears to be superior to an apical rotational algorithm because it is able to handle data from the RV inflow and outflow tracts, which

1168


Fig. 54.31: RT 3DE-apical rotation method—The top left, top right and bottom left panels show three orthogonal MPRs of the RV taken at the basal level showing discontinuity of the RV inflow and outflow tracts. (RT 3DE: Real time, three-dimensional echocardiography; RV: Right ventricle).

Fig. 54.32: RT 3DE-apical rotation method—the same 3D data set shown in Figure 54.31 is now advanced to show three orthogonal MPRs (top left, top right and bottom left panels) of the RV taken at the mid-ventricular level. (RT 3DE: Real time, three-dimensional echocardiography; RV: Right ventricle).

may appear to be discontinuous when viewed in a basal short-axis cross-section (Fig. 54.31), but not from a midshort-axis section (Fig. 54.32). Whereas the apical rotation method appears to be appropriate for the simple shape of the left ventricle, it is unable to handle data in which the contours appear to overlap (Fig. 54.31). The short-axis disc summation algorithm is identical to the algorithm used for analysis of CMR images and is able to handle discontinuous data and overlapping contours both at basal (Fig. 54.33) and mid-ventricular levels (Fig. 54.34). Test–retest variability for RTDE by disc summation was 3.3%, 8.7%, 10%, and 10.3%, respectively for EDV, ESV, and EF. Though test–retest variability for right ventricular end-diastolic volume (RVEDV), RVSV, and RVEF were acceptable (8.7%, 10%, and 10.3%, respectively) and comparable to those reported for CMR,115 these values were somewhat higher than those noted for EDV, probably reflecting variability in end-systolic video-frame selection.116 Normal reference ranges of indexed volumes (mean ± 2 SDs) for RVEDV, ESV, SV, and EF were 38.6 to 92.2 mL/m2, 7.8 to 50.6 mL/m2, 22.5 to 42.9 mL/m2, and 38.0 to 65.3%, respectively, for women and 47.0 to 100 mL/m2, 23.0 to 52.6 mL/m2, 14.2 to 48.4 mL/m2, and 29.9 to 58.4%, respectively, for men.116 These values are similar to the normal referenced indexed ranges of indexed volumes for RVEDV and RVESV by

CMR.117,118 Interstudy reproducibility of RVEDV, ESV, and EF by CMR has been reported to be 6.2%, 14.1%, and 8.3%, respectively, by Grothues et al.118 Despite encouraging preliminary results, there are still many challenges associated with routine quantification of the right ventricle. Chief among them is image quality. RT 3DE is subject to error if the right ventricle is large and a large portion of the infundibulum falls outside the near field afforded by the 90°× 90° pyramidal sector size. Thus, while this method works well in normals, its application in markedly dilated right ventricles has not been established. Additionally, if the right ventricle is large, undersampling can occur by the apical rotation method because the ventricular surface is usually convex and the volume lying between the true surface and the surface approximated by the AR algorithm is omitted, resulting in underestimation. Underestimation may also occur because the RV inflow and RV outflow tracts may be very large and may appear to be discontinuous when viewed on a single image plane and therefore not included by the volume algorithm. This can be addressed by the short-axis disc summation algorithm in which portions of the right ventricle that appear discontinuous on any given plane such as the inflow and outflow tracts can be included in the volume by summating separate discontinuous discs.


Fig. 54.33: RT 3DE-disc summation method—the top left, top right and bottom left panels show three orthogonal MPRs of the RV taken at the basal level showing discontinuity of the RV inflow and outflow tracts. (RT 3DE: Real time, three-dimensional echocardiography; RV: Right ventricle).

Fig. 54.35: RT 3DE RV automatic boundary tracking algorithm at the mid-ventricular level. (RT 3DE: Real time, three-dimensional echocardiography; LV: Left ventricle; RV, Right ventricle).

In addition, the thickness of the discs can be reduced to reduce interpolation of data between traced areas. Based on the work of Weiss et al. significant underestimation

1169

Fig. 54.34: RT 3DE-disc summation method—the same threedimensional (3D) data set shown in Figure 54.4A is now advanced to show three orthogonal MPRs (top left, top right and bottom left panels) of the RV taken at the mid-ventricular level. (RT 3DE: Real time, three-dimensional echocardiography; RV: Right ventricle).

can be minimized by including 7–10 images.119 Variable designation of end-diastolic and end-systolic frames by RT 3DE and CMR is a source of error. Differences in image acquisition approaches (RT 3DE long-axis rotational approach vs CMR short-axis cross-sectional approach) introduce different partial volume effects, which may introduce error. Endocardial boundaries may be obscured by tangential RT 3DE-apical slices, whereas variable inclusion of the right atrium and RV outflow tract may occur by CMR. Boundary tracing error remains the largest source of error. Tracing the endocardium on the white side of the black–white boundary minimizes underestimation of RT 3DE volumes when compared to CMR. Variable visualization of the apex can be minimized by carefully manipulating the entire 3D data set so that the largest long-axis is visualized and prescribing a series of short-axis images such that they are perpendicular to the long axis. Toggling between the traced endocardial boundaries as displayed in the orthogonal multiplanar reconstructions minimizes erroneous boundary tracing. Although best results are obtained with manual boundary tracing an automatic RV boundary recognition algorithm has been utilized which tracks best at the mid-RV level (Fig. 54.35). This algorithm requires manual inputs of the tricuspid annuli and the RV apex as starting points for the boundary tracking to take place. However, manual correction of the

1170


automatically generated boundaries is necessary to avoid significant underestimation.120 In particular, the base and the RV outflow tract is incompletely visualized 48% of the time requires manual correction of the automatic contours. A 3DTEE study has shown that the RV outflow tract is not circular, but oval.121 Future developments in automatic image segmentation, possibly with the help of contrast agents may improve results.

RT 3DE Studies of Congenital Heart Disease and PH The underestimation of RV volumes is particularly marked in patients who have massive ventricular dilation and is not ready for clinical use in patients with congenital heart disease.122 In PH patients, RT 3DE has shown some promise. In patients with PH, evaluation of the RV diastolic and systolic volume and EF by RT 3DE showed a higher discriminating power in comparison, respectively, with 2D RV diastolic area and the relative FACs.123 RV shape change has been studied in PH by RT 3DE. In PH, the right ventricle is more spherical with increased cross-sectional area at the mid and basal ventricular segments, basal bulging adjacent to the tricuspid valve and blunting or rounding of the apex.124 Additionally, a RT 3DE study in these patients showed that RV inflow and global systolic function was impaired in inverse relationship with pulmonary artery systolic pressure and pulmonary vascular resistance. RV systolic synchronicity was impaired in patients with severe PH.125 The RV remodels differently depending on the etiology of the disease. Grapsa et al. studied 141 consecutive patients with differing etiologies of PH (idiopathic, chronic thromboembolic disease, secondary to mitral regurgitation). Age- and gender-matched controls were also studied with RT 3DE. Overall, RVEDV was greater and RVEF lower in patient with PH compared to those with thromboembolic disease and mitral regurgitation (186.4 ± 48.8 vs 113.5 vs 109.4 mL, p < 0.001, and 33.2% vs 36.8% vs 66.8%, p < 0.001, respectively). Tricuspid valve mobility was most restricted in the thromboembolic group and least restricted in the mitral regurgitation group. Tricuspid tenting volume was greater in the thromboembolic group and PH group than in the mitral regurgitation group. Most patients with PH (54.6%) had at least moderate tricuspid regurgitation, while in the thromboembolic group, most (59.4%) had mild and only 37.5% had moderate tricuspid regurgitation (p < 0.01). Conversely, patients with mitral regurgitation (85%) had only mild tricuspid regurgitation. There was no correlation between RV systolic pressures

and the RVEF or tenting volume. Therefore, the most adverse remodeling was noted in the patients with PH.126 The same authors studied prognostic markers in these patients. An increase of right atrial (RA) sphericity index > 0.24 predicted clinical deterioration with a sensitivity of 96% and a specificity of 90% [area under the curve (AUC) = 0.97]. RV sphericity index was less sensitive (70%) and specific (62%) in predicting clinical deterioration (AUC = 0.649). The deterioration in RVEF had a sensitivity of 91.1% and a specificity of 35.3% (AUC = 0.479) in predicting clinical deterioration. The dilatation of RA > 14 mL over 1 year had high sensitivity at 82.6% but low specificity at 30.8% in predicting clinical deterioration.127 In summary, the field of 3DE has made tremendous progress over the last 25 years and is now being offered on every clinical platform. Though its efficacy and superiority over conventional techniques is now well established, there is still considerable variability of products and algorithms offered by the differing vendor platforms. This makes standardization difficult among the various platforms and also makes it difficult to gather a large enough patient database to offer long-term RT 3DE prognostic parameters. With further improvements in transducer design, image quality, temporal resolution, and standardization, it is anticipated that clinical guidelines regarding its routine use will emerge.

REFERENCES 1. Amico AF, Lichtenberg GS, Reisner SA, et al. Superiority of visual versus computerized echocardiographic estimation of radionuclide left ventricular ejection fraction. Am Heart J. 1989;118(6):1259–65. 2. King DL, Harrison MR, King DL Jr, et al. Ultrasound beam orientation during standard two-dimensional imaging: assessment by three-dimensional echocardiography. J Am Soc Echocardiogr. 1992;5(6):569–76. 3. King DL, King DL Jr, Shao MY. Three-dimensional spatial registration and interactive display of position and orientation of real-time ultrasound images. J Ultrasound Med. 1990;9(9):525–32. 4. Levine RA , Handschumacher MD, Sanfilippo AJ, et al. Three-dimensional echocardiographic reconstruction of the mitral valve, with implications for the diagnosis of mitral valve prolapse. Circulation. 1989;80(3):589–98. 5. Xu J, Wu Y, Li X, et al. Accuracy of three-dimensional quantification of left ventricular function using magnetic sensor acquisition: a dynamic in vitro model. Chin Med J. 2001;114(10):1011–14. 6. King DL, Harrison MR, King DL Jr, et al. Improved reproducibility of left atrial and left ventricular measurements by guided three-dimensional echocardiography. J Am Coll Cardiol. 1992;20(5):1238–45.


7. King DL. Errors as a result of metal in the near environment when using an electromagnetic locator with freehand threedimensional echocardiography. J Am Soc Echocardiogr. 2002;15(7):731–5. 8. Djoa KK, de Jong N, van Egmond FC, et al. A fast rotating scanning unit for real-time three-dimensional echo data acquisition. Ultrasound Med Biol. 2000;26(5):863–9. 9. Pandian NG, Nanda NC, Schwartz SL, et al. Three-dimensional and four-dimensional transesophageal echocardiographic imaging of the heart and aorta in humans using a computed tomographic imaging probe. Echocardiography. 1992;9(6):677–87. 10. Roelandt J, Salustri A , Mumm B, et al. Precordial threedimensional echocardiography with a rotational imaging probe: methods and initial clinical experience. Echocardiography. 1995;12(3):243–52. 11. Pai RG, Jintapakorn W, Tanimoto M, et al. Three-dimensional echocardiographic reconstruction of the left ventricle by a transesophageal tomographic technique: in vitro and in vivo validation of its volume measurement. Echocardiography. 1996;13(6):613–22. 12. Franke A , Flachskampf FA , Kühl HP, et al. [3-dimensional reconstruction of multiplanar transesophageal echocardiography images: a methodologic report with case examples]. Z Kardiol. 1995;84(8):633–42. 13. Pandian NG, Roelandt J, Nanda NC, et al. Dynamic threedimensional echocardiography: methods and clinical potential. Echocardiography. 1994;11(3):237–59. 14. Hozumi T, Yoshikawa J, Yoshida K, et al. Three-dimensional echocardiographic measurement of left ventricular volumes and ejection fraction using a multiplane transesophageal probe in patients. Am J Cardiol. 1996;78(9):1077–80. 15. Lang RM, Bierig M, Devereux RB, et al. Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 16. Gopal AS, King DL, Katz J, et al. Three-dimensional echocardiographic volume computation by polyhedral surface reconstruction: in vitro validation and comparison to magnetic resonance imaging. J Am Soc Echocardiogr. 1992;5(2):115–24. 17. Siu SC, Rivera JM, Guerrero JL, et al. Three-dimensional echocardiography. In vivo validation for left ventricular volume and function. Circulation. 1993;88(4 Pt 1):1715–23. 18. Gopal AS, Schnellbaecher MJ, Shen Z, et al. Freehand three-dimensional echocardiography for determination of left ventricular volume and mass in patients with abnormal ventricles: comparison with magnetic resonance imaging. J Am Soc Echocardiogr. 1997;10(8):853–61. 19. Sapin PM, Schröder KM, Gopal AS, et al. Comparison of two- and three-dimensional echocardiography with cineventriculography for measurement of left ventricular volume in patients. J Am Coll Cardiol. 1994;24(4):1054–63.

1171

20. Gopal AS, Shen Z, Sapin PM, et al. Assessment of cardiac function by three-dimensional echocardiography compared with conventional noninvasive methods. Circulation. 1995;92(4):842–53. 21. Erbel R, Schweizer P, Lambertz H, et al. Echoventriculography—a simultaneous analysis of two-dimensional echocardiography and cineventriculography. Circulation. 1983;67(1):205–15. 22. Sheikh K, Smith SW, von Ramm O, et al. Real-time, threedimensional echocardiography: feasibility and initial use. Echocardiography. 1991;8(1):119–25. 23. von Ramm OT, Smith SW. Real time volumetric ultrasound imaging system. J Digit Imaging. 1990;3(4):261–6. 24. Snyder JE, Kisslo J, von Ramm O. Real-time orthogonal mode scanning of the heart. I. System design. J Am Coll Cardiol. 1986;7(6):1279–85. 25. Badano LP, Boccalini F, Muraru D, et al. Current clinical applications of transthoracic three-dimensional echocardiography. J Cardiovasc Ultrasound. 2012;20(1):1–22. 26. Hung J, Lang R, Flachskampf F, et al; ASE. 3D echocardiography: a review of the current status and future directions. J Am Soc Echocardiogr. 2007;20(3):213–33. 27. Schmidt MA , Ohazama CJ, Agyeman KO, et al. Real-time three-dimensional echocardiography for measurement of left ventricular volumes. Am J Cardiol. 1999;84(12):1434–9. 28. Lee D, Fuisz AR, Fan PH, et al. Real-time 3-dimensional echocardiographic evaluation of left ventricular volume: correlation with magnetic resonance imaging—a validation study. J Am Soc Echocardiogr. 2001;14(10):1001–9. 29. Kühl HP, Schreckenberg M, Rulands D, et al. High-resolution transthoracic real-time three-dimensional echocardiography: quantitation of cardiac volumes and function using semi-automatic border detection and comparison with cardiac magnetic resonance imaging. J Am Coll Cardiol. 2004;43(11):2083–90. 30. Arai K, Hozumi T, Matsumura Y, et al. Accuracy of measurement of left ventricular volume and ejection fraction by new real-time three-dimensional echocardiography in patients with wall motion abnormalities secondary to myocardial infarction. Am J Cardiol. 2004;94(5):552–8. 31. Jenkins C, Bricknell K, Hanekom L, et al. Reproducibility and accuracy of echocardiographic measurements of left ventricular parameters using real-time three-dimensional echocardiography. J Am Coll Cardiol. 2004;44(4): 878–86. 32. Corsi C, Lang RM, Veronesi F, et al. Volumetric quantification of global and regional left ventricular function from real-time three-dimensional echocardiographic images. Circulation. 2005;112(8):1161–70. 33. Jacobs LD, Salgo IS, Goonewardena S, et al. Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data. Eur Heart J. 2006;27(4):460–8. 34. Mor-Avi V, Sugeng L, Lang RM. Real-time 3-dimensional echocardiography: an integral component of the routine echocardiographic examination in adult patients? Circulation. 2009;119(2):314–29.

1172


35. Gopal AS, Chukwu, EO, et al. Relative importance of errors in left ventricular quantitation: insights from three-dimensional echocardiography and cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2008;21(9):990–7. 36. Mor-Avi V, Jenkins C, Kühl HP, et al. Real-time 3-dimensional echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error. JACC Cardiovasc Imaging. 2008;1(4):413–23. 37. Dorosz JL, Lezotte DC, Weitzenkamp DA, et al. Performance of 3-dimensional echocardiography in measuring left ventricular volumes and ejection fraction: a systematic review and meta-analysis. J Am Coll Cardiol. 2012;59(20): 1799–808. 38. Miller CA, Pearce K, Jordan P, et al. Comparison of realtime three-dimensional echocardiography with cardiovascular magnetic resonance for left ventricular volumetric assessment in unselected patients. Eur Heart J Cardiovasc Imaging. 2012;13(2):187–95. 39. Moceri P, Doyen D, Bertora D, et al. Real time three-dimensional echocardiographic assessment of left ventricular function in heart failure patients: underestimation of left ventricular volume increases with the degree of dilatation. Echocardiography. 2012;29(8):970–7. 40. Thavendiranathan P, Liu S, Verhaert D, et al. Feasibility, accuracy, and reproducibility of real-time full-volume 3D transthoracic echocardiography to measure LV volumes and systolic function: a fully automated endocardial contouring algorithm in sinus rhythm and atrial fibrillation. JACC Cardiovasc Imaging. 2012;5(3):239–51. 41. Coon PD, Pollard H, Furlong K, et al. Quantification of left ventricular size and function using contrast-enhanced real-time 3D imaging with power modulation: comparison with cardiac MRI. Ultrasound Med Biol. 2012;38(11): 1853–8. 42. Muraru D, Badano LP, Peluso D, et al. Comprehensive analysis of left ventricular geometry and function by threedimensional echocardiography in healthy adults. J Am Soc Echocardiogr. 2013;26(6):618–28. 43. Chahal NS, Lim TK, Jain P, et al. Population-based reference values for 3D echocardiographic LV volumes and ejection fraction. JACC Cardiovasc Imaging. 2012;5(12):1191–7. 44. Wijns W, Serruys PW, Slager CJ, et al. Effect of coronary occlusion during percutaneous transluminal angioplasty in humans on left ventricular chamber stiffness and regional diastolic pressure-radius relations. J Am Coll Cardiol. 1986; 7(3):455–63. 45. Fujiyabashi Y, Chang BL, Rajagopalan RE, et al. Comparative echocardiographic study of recovery of diastolic dysfunction after brief periods of coronary occlusion: differential effects of intravenous nifedipine administered before and during occlusion. J Am Coll Cardiol, 1985;6:1289–98. 46. Nagueh SF, Kopelen HA , Zoghbi WA. Effects of adenosine on left ventricular filling dynamics in patients with and without coronary artery disease: a Doppler echocardiographic study. Am Heart J. 1998;135(4):647–54.

47. Sharir T, Germano G, Kang X, et al. Prediction of myocardial infarction versus cardiac death by gated myocardial perfusion SPECT: risk stratification by the amount of stressinduced ischemia and the poststress ejection fraction. J Nucl Med. 2001;42(6):831–7. 48. Skalidis EI, Parthenakis FI, Patrianakos AP, et al. Regional coronary flow and contractile reserve in patients with idiopathic dilated cardiomyopathy. J Am Coll Cardiol. 2004;44(10):2027–32. 49. Maffessanti F, Nesser HJ, Weinert L, et al. Quantitative evaluation of regional left ventricular function using three-dimensional speckle tracking echocardiography in patients with and without heart disease. Am J Cardiol. 2009;104(12):1755–62. 50. Bogaert J, Dymarkowski S, Taylor AM, et al. Clinical Cardiac MRI. 2nd ed. Heidelberg: Springer, 2012; 130–9. 51. Moore CC, Lugo-Olivieri CH, McVeigh ER, et al. Threedimensional systolic strain patterns in the normal human left ventricle: characterization with tagged MR imaging. Radiology. 2000;214(2):453–66. 52. Young AA, Kramer CM, Ferrari VA, et al. Three-dimensional left ventricular deformation in hypertrophic cardiomyopathy. Circulation. 1994;90(2):854–67. 53. Azhari H, Weiss JL, Rogers WJ, et al. Noninvasive quantification of principal strains in normal canine hearts using tagged MRI images in 3-D. Am J Physiol. 1993;264(1 Pt 2): H205–216. 54. Nesser HJ, Mor-Avi V, Gorissen W, et al. Quantification of left ventricular volumes using three-dimensional echocardiographic speckle tracking: comparison with MRI. Eur Heart J. 2009;30(13):1565–73. 55. Kleijn SA , Aly MF, Terwee CB, et al. Three-dimensional speckle tracking echocardiography for automatic assessment of global and regional left ventricular function based on area strain. J Am Soc Echocardiogr. 2011;24(3):314–21. 56. Reant P, Barbot L, Touche C, et al. Evaluation of global left ventricular systolic function using three-dimensional echocardiography speckle-tracking strain parameters. J Am Soc Echocardiogr. 2012;25(1):68–79. 57. Wen H, Liang Z, Zhao Y, et al. Feasibility of detecting early left ventricular systolic dysfunction using global area strain: a novel index derived from three-dimensional speckle-tracking echocardiography. Eur J Echocardiogr. 2011;12(12):910–6. 58. Hayat D, Kloeckner M, Nahum J, et al. Comparison of real-time three-dimensional speckle tracking to magnetic resonance imaging in patients with coronary heart disease. Am J Cardiol. 2012;109(2):180–6. 59. Mor-Avi V, Lang RM, Badano LP, et al. Current and evolving echocardiographic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocardiography. Eur J Echocardiogr. 2011;12(3):167–205. 60. Levy D, Garrison RJ, Savage DD, et al. Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study. N Engl J Med. 1990;322(22):1561–6.


61. Byrd BF 3rd, Wahr D, Wang YS, et al. Left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in normal adults. J Am Coll Cardiol. 1985;6(5):1021–5. 62. Gottdiener JS, Livengood SV, Meyer PS, et al. Should echocardiography be performed to assess effects of antihypertensive therapy? Test-retest reliability of echocardiography for measurement of left ventricular mass and function. J Am Coll Cardiol. 1995;25(2):424–30. 63. Sapin PM, Gopal AS, Clarke GB, et al. Three-dimensional echocardiography compared to two-dimensional echocardiography for measurement of left ventricular mass anatomic validation in an open chest canine model. Am J Hypertens. 1996;9(5):467–74. 64. Gopal AS, Keller AM, Shen Z, et al. Three-dimensional echocardiography: in vitro and in vivo validation of left ventricular mass and comparison with conventional echocardiographic methods. J Am Coll Cardiol. 1994;24(2): 504–13. 65. Gopal AS, Schnellbaecher MJ, Shen Z, et al. Freehand three-dimensional echocardiography for measurement of left ventricular mass: in vivo anatomic validation using explanted human hearts. J Am Coll Cardiol. 1997;30(3): 802–10. 66. Mor-Avi V, Sugeng L, Weinert L, et al. Fast measurement of left ventricular mass with real-time three-dimensional echocardiography: comparison with magnetic resonance imaging. Circulation. 2004;110(13):1814–8. 67. Chang SA, Kim HK, Lee SC, et al. Assessment of left ventricular mass in hypertrophic cardiomyopathy by realtime three-dimensional echocardiography using single-beat capture image. J Am Soc Echocardiogr. 2013;26(4):436–42. 68. Shimada YJ, Shiota T. Meta-analysis of accuracy of left ventricular mass measurement by three-dimensional echocardiography. Am J Cardiol. 2012;110(3):445–52. 69. King DL, King Jr. DL, Gopal AS, et al. Myocardial infarct reconstruction and sizing by three-dimensional echocardiography. In: Proceedings of the Computers in Cardiology 1992; October 11–14, 1992, Durham, NC. IEEE Computer Society Press. Los Alamitos, CA. pp. 627–30. 70. King DL, Gopal AS, King DL Jr, et al. Three-dimensional echocardiography: in vitro validation for quantitative measurement of total and “infarct” surface area. J Am Soc Echocardiogr. 1993;6(1):69–76. 71. Gopal AS, Keller AM, Rigling R, et al. Left ventricular volume and endocardial surface area by three-dimensional echocardiography: comparison with two-dimensional echocardiography and nuclear magnetic resonance imaging in normal subjects. J Am Coll Cardiol. 1993;22(1):258–70. 72. King DL, Gopal AS, Schroeder KM, et al. Ratio of infarct subtended volume to surface area by 3D echocardiography: In vivo measurement of infarct expansion and aneurysm formation. In: Proceedings of the Computers in Cardiology 1993; September 5–8, 1993, London, UK. IEEE Computer Society Press. Los Alamitos, CA. pp. 17–20. 73. Maffessanti F, Lang RM, Corsi C, et al. Feasibility of left ventricular shape analysis from transthoracic real-time 3-D echocardiographic images. Ultrasound Med Biol. 2009; 35(12):1953–62.

1173

74. Corsi C, Lang RM, Veronesi F, et al. Volumetric quantification of global and regional left ventricular function from real-time three-dimensional echocardiographic images. Circulation. 2005;112(8):1161–70. 75. Gopal AS, Schnellbaecher MJ, Shen Z, et al. Clinical use of 3D echocardiography for serial assessment of left ventricular mass regression in hypertensive patients (abstr). J Am Soc Echocardiogr. 1995;8:387. 76. Thavendiranathan P, Grant AD, Negishi T, et al. Reproducibility of echocardiographic techniques for sequential assessment of left ventricular ejection fraction and volumes: application to patients undergoing cancer chemotherapy. J Am Coll Cardiol. 2013;61(1):77–84. 77. Gopal AS, Chukwu EO, Mihalatos DG, et al. Left ventricular structure and function for postmyocardial infarction and heart failure risk stratification by three-dimensional echocardiography. J Am Soc Echocardiogr. 2007;20(8): 949–58. 78. Tulevski II, Dodge-Khatami A , Groenink M, et al. Right ventricular function in congenital cardiac disease: noninvasive quantitative parameters for clinical follow-up. Cardiol Young. 2003;13(5):397–403. 79. Eysmann SB, Palevsky HI, Reichek N, et al. Two-dimensional and Doppler-echocardiographic and cardiac catheterization correlates of survival in primary pulmonary hypertension. Circulation. 1989;80(2):353–60. 80. Quiroz R, Kucher N, Schoepf UJ, et al. Right ventricular enlargement on chest computed tomography: prognostic role in acute pulmonary embolism. Circulation. 2004;109 (20):2401–4. 81. Zornoff LA , Skali H, Pfeffer MA, et al. SAVE Investigators. Right ventricular dysfunction and risk of heart failure and mortality after myocardial infarction. J Am Coll Cardiol. 2002;39(9):1450–5. 82. Ferlinz J. Measurements of right ventricular volumes in man from single plane cineangiograms. A comparison to the biplane approach. Am Heart J. 1977;94(1):87–90. 83. Kaul S, Boucher CA, Okada RD, et al. Sources of variability in the radionuclide angiographic assessment of ejection fraction: a comparison of first-pass and gated equilibrium techniques. Am J Cardiol. 1984;53(6):823–8. 84. Bommer W, Weinert L, Neumann A , et al. Determination of right atrial and right ventricular size by two-dimensional echocardiography. Circulation. 1979;60(1):91–100. 85. Saito A, Ueda K, Nakano H. Right ventricular volume determination by two-dimensional echocardiography. J Cardiogr. 1981;11(4):1159–68. 86. Ninomiya K, Duncan WJ, Cook DH, et al. Right ventricular ejection fraction and volumes after mustard repair: correlation of two dimensional echocardiograms and cineangiograms. Am J Cardiol. 1981;48(2):317–24. 87. Watanabe T, Katsume H, Matsukubo H, et al. Estimation of right ventricular volume with two dimensional echocardiography. Am J Cardiol. 1982;49(8):1946–53. 88. Aebischer NM, Czegledy F. Determination of right ventricular volume by two-dimensional echocardiography with a crescentic model. J Am Soc Echocardiogr. 1989;2(2): 110–18.

1174


89. Levine RA, Gibson TC, Aretz T, et al. Echocardiographic measurement of right ventricular volume. Circulation. 1984;69(3):497–505. 90. Czegledy FP, Katz J. A new geometric description of the right ventricle. J Biomed Eng. 1993;15(5):387–91. 91. Gibson TC, Miller SW, Aretz T, et al. Method for estimating right ventricular volume by planes applicable to crosssectional echocardiography: correlation with angiographic formulas. Am J Cardiol. 1985;55(13 Pt 1): 1584–8. 92. Tomita M, Masuda H, Sumi T, et al. Estimation of right ventricular volume by modified echocardiographic subtraction method. Am Heart J. 1992;123(4 Pt 1):1011–22. 93. Trowitzsch E, Colan SD, Sanders SP. Two-dimensional echocardiographic estimation of right ventricular area change and ejection fraction in infants with systemic right ventricle (transposition of the great arteries or hypoplastic left heart syndrome). Am J Cardiol. 1985;55(9):1153–7. 94. Denslow S, Wiles HB. Right ventricular volumes revisited: a simple model and simple formula for echocardiographic determination. J Am Soc Echocardiogr. 1998;11(9):864–73. 95. Dorosz JL, Bolson EL, Waiss MS, et al. Three-dimensional visual guidance improves the accuracy of calculating right ventricular volume with two-dimensional echocardiography. J Am Soc Echocardiogr. 2003;16(6):675–81. 96. Reiter SJ, Rumberger JA , Feiring AJ, et al. Precision of measurements of right and left ventricular volume by cine computed tomography. Circulation. 1986;74(4):890–900. 97. Sechtem U, Pflugfelder PW, Gould RG, et al. Measurement of right and left ventricular volumes in healthy individuals with cine MR imaging. Radiology. 1987;163(3):697–702. 98. Linker DT, Moritz WE, Pearlman AS. A new three-dimensional echocardiographic method of right ventricular volume measurement : in vitro validation. J Am Coll Cardiol. 1986;8(1):101–6. 99. Buckey JC, Beattie JM, Nixon JV, et al. Right and left ventricular volumes in vitro by a new nongeometric method. Am J Card Imaging. 1987;1(3):227–33. 100. Jiang L, Handschumacher MD, Hibberd MG, et al. Three-dimensional echocardiographic reconstruction of right ventricular volume: in vitro comparison with twodimensional methods. J Am Soc Echocardiogr. 1994;7(2): 150–8. 101. Apfel HD, Shen Z, Boxt LM, et al. Three-dimensional echocardiographic assessment of right ventricular volume and function in patients with pulmonary hypertension. Cardiol Young. 1997;7:317–24. 102. Pini R, Giannazzo G, Di Bari M, et al. Transthoracic threedimensional echocardiographic reconstruction of left and right ventricles : in vitro validation and comparison with magnetic resonance imaging. Am Heart J. 1997;133(2): 221–9. 103. Vogel M, Gutberlet M, Dittrich S, et al. Comparison of transthoracic three dimensional echocardiography with magnetic resonance imaging in the assessment of right ventricular volume and mass. Heart. 1997;78(2):127–30.

104. Fujimoto S, Mizuno R, Nakagawa Y, et al. Estimation of the right ventricular volume and ejection fraction by transthoracic three-dimensional echocardiography. A validation study using magnetic resonance imaging. Int J Card Imaging. 1998;14(6):385–90. 105. Papavassiliou DP, Parks WJ, Hopkins KL, et al. Threedimensional echocardiographic measurement of right ventricular volume in children with congenital heart disease validated by magnetic resonance imaging. J Am Soc Echocardiogr. 1998;11(8):770–7. 106. Shiota T, Jones M, Chikada M, et al. Real-time three-dimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload. Circulation. 1998;97(19):1897–900. 107. Heusch A , Rübo J, Krogmann ON, et al. Volumetric analysis of the right ventricle in children with congenital heart defects: comparison of biplane angiography and transthoracic 3-dimensional echocardiography. Cardiol Young. 1999;9(6):577–84. 108. Hubka M, Mantei K, Bolson E, et al. Measurement of right ventricular mass and volume by three-dimensional echocardiography by freehand scanning. Comput Cardiol. 2000;27:703–6. 109. Schindera ST, Mehwald PS, Sahn DJ, et al. Accuracy of real-time three-dimensional echocardiography for quantifying right ventricular volume: static and pulsatile flow studies in an anatomic in vitro model. J Ultrasound Med. 2002;21(10):1069–75. 110. Angelini ED, Homma S, Pearson G, et al. Segmentation of real-time three-dimensional ultrasound for quantification of ventricular function: a clinical study on right and left ventricles. Ultrasound Med Biol. 2005;31(9):1143–58. 111. Wang J, Wang X, Xie M, et al. Evaluation of right ventricular volume and systolic function by realtime three-dimensional echocardiography. J Huazhong Univ Sci Technol Med Sci. 2005;25(1):94–6, 99. 112. Menzel T, Kramm T, Brückner A, et al. Quantitative assessment of right ventricular volumes in severe chronic thromboembolic pulmonary hypertension using transthoracic three-dimensional echocardiography: changes due to pulmonary thromboendarterectomy. Eur J Echocardiogr. 2002;3(1):67–72. 113. Leotta DF, Munt B, Bolson EL, et al. Quantitative threedimensional echocardiography by rapid imaging from multiple transthoracic windows: in vitro validation and initial in vivo studies. J Am Soc Echocardiogr. 1997;10(8): 830–9. 114. Ota T, Fleishman CE, Strub M, et al. Real-time, threedimensional echocardiography: feasibility of dynamic right ventricular volume measurement with saline contrast. Am Heart J. 1999;137(5):958–66. 115. Grothues F, Moon JC, Bellenger NG, et al. Interstudy reproducibility of right ventricular volumes, function, and mass with cardiovascular magnetic resonance. Am Heart J. 2004;147(2):218–23.


116. Gopal AS, Chukwu EO, Iwuchukwu CJ, et al. Normal values of right ventricular size and function by real-time 3-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20(5):445–55. 117. Rominger MB, Bachmann GF, Pabst W, et al. Right ventricular volumes and ejection fraction with fast cine MR imaging in breath-hold technique: applicability, normal values from 52 volunteers, and evaluation of 325 adult cardiac patients. J Magn Reson Imaging. 1999;10(6):908–18. 118. Alfakih K, Plein S, Thiele H, et al. Normal human left and right ventricular dimensions for MRI as assessed by turbo gradient echo and steady-state free precession imaging sequences. J Magn Reson Imaging. 2003;17(3):323–9. 119. Weiss JL, Eaton LW, Kallman CH et al. Accuracy of volume determination by two-dimensional echocardiography defining requirements under controlled conditions in the ejecting canine left ventricle. Circulation. 1982;67:889–95. 120. Ostenfeld E, Carlsson M, Shahgaldi K, et al. Manual correction of semiautomatic three-dimensional echocardiography is needed for right ventricular assessment in adults: validation with cardiac magnetic resonance. Cardiovasc Ultrasound. 2012;10:1. 121. Izumo M, Shiota M, Saitoh T, et al. Non-circular shape of right ventricular outflow tract: a real-time 3-dimensional transesophageal echocardiography study. Circ Cardiovasc Imaging. 2012;5(5):621–7.

1175

122. Crean AM, Maredia N, Ballard G, et al. 3D echo systematically underestimates right ventricular volumes compared to cardiovascular magnetic resonance in adult congenital heart disease with moderate to severe right ventricular dilatation. J Cardiovasc Magn Reson. 2011;13:78. 123. Di Bello V, Conte L, Delle Donne MG, et al. Advantages of real time three-dimensional echocardiography in the assessment of right ventricular volumes and function in patients with pulmonary hypertension compared with conventional two-dimensional echocardiography. Echocardiography. 2013 124. Leary PJ, Kurtz CE, Hough CL, et al. Three-dimensional analysis of right ventricular shape and function in pulmonary hypertension. Pulm Circ. 2012;2(1):34–40. 125. Kong D, Shu X, Dong L, et al. Right ventricular regional systolic function and dyssynchrony in patients with pulmonary hypertension evaluated by three-dimensional echocardiography. J Am Soc Echocardiogr. 2013;26(6):649–56. 126. Grapsa J, Gibbs JS, Dawson D, et al. Morphologic and functional remodeling of the right ventricle in pulmonary hypertension by real time three dimensional echocardiography. Am J Cardiol. 2012;109(6):906–13. 127. Grapsa J, Gibbs JS, Cabrita IZ, et al. The association of clinical outcome with right atrial and ventricular remodelling in patients with pulmonary arterial hypertension: study with real-time three-dimensional echocardiography. Eur Heart J Cardiovasc Imaging. 2012;13(8):666–72.

CHAPTER 55 Newer Aspects of Structure/Function to Assess Cardiac Motion Gerald Buckberg, Navin C Nanda, Julien IE Hoffman, Cecil Coghlan

Snapshot  State-of-the-Art  Composite of State-of-the-Art Reports  Novel Mechanical and Timing Interdependence

Between Torsion and UntwisƟng

INTRODUCTION Cardiac motion, until recently, had been thought to follow the observations of William Harvey, who dissected cadaver hearts and deduced that the heart underwent constriction for ejection and dilation for filling, “acting like a water bellows”. Keith1 delivered the classic article on structure and function during presentation of his 1918 Harveian Lecture, and called Harvey the “functional anatomist” who emphasized that “we cannot claim to have mastered the mechanism of the human heart until we have a fundamental explanation of its architecture”. Keith described the cardiac architecture to contain circumferential and helical fibers, as he perhaps relied upon the observations of Lower2 in the 1600s describing that the cardiac apex showed helical fibers, or Senac in the 1700s,3 who defined an internal helix and surrounding transverse circumferential fibers, or Krehl’s 1800s description4 of its powerful circumferential fibers that cause cardiac constriction during ejection. Physiological recordings of pressure and flow have clearly defined the impact of ventricular performance on these variables, but their cause is determined by the function of the underlying ventricular structure (Figs. 55.1A to C).

 The Normal Heart  The Septum  The Right Ventricle  Other ConsideraƟons

Cardiac movement had been analyzed by two-dimensional (2D) methods like the ventriculogram and echocardiogram that display its narrowing, shortening, lengthening, and widening motions. Now, three-dimensional (3D) imaging is available due to development of magnetic resonance imaging (MRI) and speckle tracking imaging (STI; Figs 55.2A and B), so that the natural twisting movement to develop torsion and uncoiling to permit suction for rapid filling becomes evident; these motions become impaired by a spectrum of cardiac diseases. The newer 3D observations appropriately supplement the 2D measurements, as all six movements have become accepted descriptors of cardiac motion. Recognition of the form/function relationship is essential in order to determine how the interweaving circular and helical fibers cause them. Just as the anatomist observes structure and deduces function, those that use the echocardiogram have observed motion and deduced structure. Solution to this problem occurs when structure is understood, so that function can be explained, and that is the goal of this review. The infrastructure for explaining this macroscopic structure/function relationship involves knowledge of the functional anatomy of the heart. In 1942, Robb and

Chapter 55: Newer Aspects of Structure/Function to Assess Cardiac Motion

1177

Robb5 summarized the findings of anatomists over five centuries, and expressed generalized agreement that the heart structure includes a helical configuration that contains an apex, together with a circumferential muscle mass that occupies upper two-thirds of the cardiac base. Disagreement has existed as to the exact layering positions that are occupied by the overlapping circumferential and helical fibers. Grant,6 Lev,7 and Anderson8 have voiced concern about how the microscopic connections between the fiber tracts are always dislodged during manual dissection. Francisco Torrent-Guasp did a hand dissection of the ventricles in his effort to define “functional pathways”, and his work demonstrated that the unscrolled heart appeared like a rope-like model when stretched from the pulmonary artery to the aorta.9,10 His dissection demonstrated that the intact heart contains two interconnected loops containing a circumferential and helical muscle mass and his configuration is called the helical ventricular myocardial band or HVMB; this anatomy will be described in detail, as it forms the basis of the structure/function analysis in this review11 (Fig. 55.3). The role of this functional analysis is to adhere to Harvey’s functional anatomist requirement so that we can integrate helical and circular fiber tracts in order to explain reasons for the readily observed narrowing, shortening, lengthening, widening, twisting, and uncoiling motions. Current echocardiography movement analysis demonstrates each of these motions, yet their conventional “state-of-the-art” reports have consistently failed to consider the circumferential muscle.12–15 Conversely, the

The heart is a muscular pump that supplies blood containing oxygen and nutrients to the body. This goal is achieved by electrical excitation that produces sequential ventricular emptying and filling. Figure 55.1 demonstrates the physiological sequence of ventricular function—a contraction phase to develop pre-ejection tension, ejection, and rapid and slow periods for filling. This report relates the function to the underlying precisely described muscular anatomy, thereby providing novel structural explanations for the contractile sequence that causes the ventricular directional motions of narrowing, shortening, lengthening, widening, and twisting and uncoiling (see Fig. 55.1A to C). The observed functional patterns (see Figs 55.2A and B) are documented by MRI and include an initial global counterclockwise rotation and attendant narrowing or “cocking” in the isovolumic contraction (IVC) phase before ejection, followed by twisting of the cardiac apex in a counterclockwise direction and of the base in a clockwise direction as the ventricle longitudinally shortens during the ejection phase, followed by a vigorous

A

B1

Figs 55.1A and B

functional HVMB provides an explanation for how the interacting circular and helical fibers cause each of these actions, as this information was gleaned from motion studies using sonomicrometer crystals, MRI, diffusion tensor magnetic resonance imaging (DTMRI), 2D echocardiogram, 3D STI, velocity vector imaging (VVI), and radionuclide ventriculography.16–18

BASIC HEART FUNCTION

1178


B2

B3

B4

C

Figs 55.1A to C: (A) Currently accepted time frames of systole and diastole, with measurements of intravascular pressure in the aorta, left ventricle (LV), left atrium (LA), and LV volume, together with their impact on the mitral and aortic valves. Aortic flow occurs between the two intervals that define ejection. The physiological phases of cardiac cycle that include isovolumic contraction, ejection, isovolumic “relaxation” (to be questioned in this report), rapid and slow filling, and atrial contraction are shown; (B) Two-dimensional images of the LV in a longitudinal view that shows the normal sequence of narrowing, shortening, lengthening, and widening of the ventricular cavity during a normal cardiac cycle. Images were obtained by epicardial imaging in an open-chest porcine preparation. The phases of the cardiac cycle include end-diastolic state (B4), isometric phase (B1), ejection (B2), and isovolumic phase (B3). The broken-line markers are within the ventricular cavity and define the transverse (between the midendocardial walls) and the longitudinal (from apical endocardium to a line across the mitral annulus) dimensions. Muscle thickness is shown by the dark area adjacent to these intracavity dimensional lines. The pale color is the cavity. The predominant changes exist with muscular thickening that narrows and widens the cavity rather than the external wall dimensional changes. Note progressive muscular thickening (evaluated by wider distance between epicardial and endocardial lines as myocardial mass narrows and shortens for ejection), together with maintained thickness as heart lengthens during the rapid filling phase before substantial widening; (C) Twist of the heart: clockwise (below baseline) and counterclockwise (above baseline) motions of the base and apex, respectively, during the cardiac ejection and filling periods are represented in rotational degrees with the use of speckle tracking with marker placed at the LV endocardial surface (Echopac PC V 6, GE Healthcare, Milwaukee, WI, USA). The relationships between the initial uniform and then reciprocal twisting motions of the base and apex during the pre-ejection, ejection, and rapid and slow filling periods are explained in the text.


1179

A

B

Figs 55.2A and B: (A) Magnetic resonance imaging (MRI) phase contrast velocity mapping (tissue phase mapping) of systolic and diastolic cardiac frames with a temporal resolution of 13.8 ms during free breathing in a healthy volunteer. All motions are described in the text; the arrows show the clockwise (marker to right) and counterclockwise (marker to left) directions of transmural twisting motion during the short-axis view and are obtained during isovolumic contraction, midsystole, isovolumic “relaxation” phase, and slower filling in mid-diastole; (B) Differences in mean values for tracing radial, tangential, and longitudinal velocity motion, each 13.8 ms, for 12 volunteer subjects in whom basal, mid, and apical segments are analyzed. Values above zero line indicate contraction, clockwise motion, and shortening; below the zero line, values define expansion, counterclockwise motion, and lengthening. The line expansion time is end systole (ES), with an average 320 ms time frame. Note early radial expansion in basal segment (a), reversal of twisting before end of systole (b), and supplemental late counterclockwise base motion during systole (c).

1180


A

B

Figs 55.3A and B: (A) Myocardial fiber organization. (a) Mall and MacCallum’s suggestion of bundles, which include deep (circular) and oblique bulbospiral tracts. (b) Rushmer’s functional model, which includes the central transverse constrictor muscle and oblique clockwise and counterclockwise layers. (c) Torrent-Guasp’s fiber trajectory model showing an upper transverse circumferential muscle (or basal loop) surrounding the oblique right- and left-handed helical apical loop; (B) (a) Diffusion tensor magnetic resonance imaging (DTMRI) studies where water is diffused parallel to fiber orientation, showing a helical positive or right-handed helix or clockwise (red) and negative or left-handed helix or counterclockwise (yellow) muscle of myofibers reflecting circumferential or horizontal with a zero helix angle. Note absence of circumferential or circular fibers in the septum, and how these zero angle helix fibers encircle the left and right ventricles. (b) Dissected heart showing the circumferential or basal loop fibers encircling the left and right ventricles that are not present in septum, and overlapping left and right helical fibers of the apical loop in septum.

global untwisting in a clockwise direction as the ventricle lengthens and slightly widens during a phase interval where no blood enters or leaves the ventricular chamber. This untwisting motion continues into the rapid filling interval, and finally a phase of relaxation exists during diastole as heart widening continues during the slower filling period before the atrium contracts during initiation of the next organized beat. The helical and circumferential muscle mass of the intact heart causes these movements, and explaining how they cause these integrated motions is our goal.

STATE-OF-THE-ART The underlying myocardial muscle mass is composed of helical and circumferential fibers, even though their origins are uncertain.6,7,19 There is general agreement from DTMRI studies that the basal two thirds of the left ventricular (LV) free wall contains three layers of muscle. These correspond to the layers defined by Streeter20 who found that the inner 20% of the wall had subendocardial fibers with an average angle of about +60°, where the positive sign indicates counterclockwise rotation above the equator, the outer 25% of the wall had subepicardial

fibers with an average angle of −50° (clockwise rotation below the equator), and the remaining 55% of midwall muscle fibers had an approximately horizontal (equatorial or circumferential) orientation. Streeter found that the apical one third of the LV had no circumferential fibers, but there is less certainty about the composition of the septum. Many studies by DTMRI or polarized light show three comparable layers,21–24 yet others show only two oblique layers without a circular component25,26 (Fig. 55.3B). The VVI method that will subsequently be shown will confirm the presence of two oblique layers, as this functional measurement provides best evidence of its structural arrangement.17 Moreover, ultrahigh frequency ultrasound functional studies show that these two septal layers are separated by a thin midseptum bright echo line partition, and that they contract independently during thickening to develop a similar longitudinal motion.18 The thinner right ventricular (RV) side corresponds to the subepicardial fibers of the free wall, and the thicker LV side conforms to the free wall subendocardial fibers. Based on studies by Streeter and previous investigators, the noncircumferential fibers form helices16,27,28 that are composed of oppositely wound oblique fibers that comprise a right-handed arm within the deeper


(subendocardial) muscle and a left-handed arm that occupies superficial (subepicardial) muscle. The HVMB model of Torrent-Guasp shows that these right and left helical arms form an apical loop; the right-handed arm is called the descending segment and the left-handed arm is called the ascending segment.10,29 Circular fibers with transverse orientation19,29,30 surround the LVs and RVs, and these are called the right and left segments of the basal loop within the HVMB (Figs 55.4A and B). The HVMB model is displayed in the major anatomy texts written by Clemente31 and by Moore and Dalley.32 The interaction between the helical and circular fibers provide the mechanical reasons for the rotational motions that are observed by imaging studies and will be subsequently defined for IVC, ejection, postejection isovolumic phase, and rapid filling. Mathematic modeling by Sallin33 defined the vital importance of fiber direction in causing function, as the oblique helical fibers produce a 60% ejection fraction, while the transverse orientation of the circumferential fibers cause a 30% ejection fraction. The integrity of fiber orientation is related to the extracellular collagen scaffold, which governs muscle alignment, ventricular shape, and size. The spiral fibrillar structure of endomysial collagen supports the spatial distribution of myocytes by a weave that ensheathes the HVMB structure described in detail34 as profound heart failure follows collagen scaffold damage in hearts that do not have direct myocyte disease.35 The different muscular components contract asynchronously. For example, sonomicrometer crystal studies show that the subepicardial muscle does not contract during the isovolumic pre-ejection interval (IVC), both subendocardial and subepicardial muscles contract and contribute to torsion during ejection, and only the subepicardial muscle continues to contract during postejection isovolumic phase when untwisting or recoil occurs.16,36 This scheme of asynchronous contraction underscores the incorrectness of traditional thinking that states that the ventricle contracts synchronously. “Dominance” defines the governing muscular force causing the directional and rotational motions during each heartbeat, as the interweaving helical and circular cardiac muscles co-contract and/or recoil during each of the IVC, twisting, and untwisting phases. For example, when considering the helical muscles, only the deep righthanded helical muscle contracts during IVC, whereas only the superficial left-handed helical muscle contracts during the isovolumic pre-filling phase. These helical muscles are antagonistic, so that the contracting helical muscle

1181

is unopposed during each pre- and postejection phase, yet one of them becomes the dominant muscle when the entire helix co-contracts during ejection, whereby the torque of the subepicardial muscle rotates the cardiac apex counterclockwise, while the subendocardial muscle contraction causes the basal clockwise motion that produces shortening.16,17 Similar distinctions exist during shortening for ejection, because the circular muscles cause compression, yet the cardiac longitudinal dimension is reduced, thus indicating that the helical fibers have dominant power to oppose the elongation that would otherwise occur from constriction, as they did during IVC. Furthermore, the net counterclockwise and clockwise rotational directions that exist during IVC and uncoiling (untwisting)16,17 are governed by the most powerful component within these overlapping circular and helical muscular components.

COMPOSITE OF STATE-OF-THE-ART REPORTS Prior imaging reports only address the helical component as a smooth change from a left-handed helix in the subepicardium into a right-handed helix in the subendocardium, without considering actions of the anatomical circular fiber structure that remains the centerpiece of anatomical descriptions (Fig. 55.5),4,37–39 and whose presence is further confirmed by DTMRI recordings25,26 (Fig. 55.3B). The mechanisms for twisting, whereby the apex rotates counterclockwise and the base rotates clockwise, has been based upon the Taber model of a single helical layered architecture,40 where obliquely aligned muscle fibers are embedded in an isotropic matrix. This engineering design states that torsion develops within each layer so that epicardial fiber contraction rotates the apex in a counterclockwise and the base in clockwise direction, while subendocardial region contraction will rotate the LV apex and base in exactly the opposite directions. In contrast, this description of torsion within each right- and left-handed helix differs from the current mechanistic descriptions by showing that torsion develops between each arm of the helix, whereby there is clockwise motion of the entire right-handed arm and a counterclockwise motion of the entire left-handed arm16,17 (Fig. 55.6). When both helical layers contract simultaneously during ejection, the larger radius of rotation for the outer epicardial layer provides a mechanical advantage

1182


A

B1

B2

B3

B4

Figs 55.4A and B: (A) Unscrolled myocardial band model of Torrent-Guasp that contains a circumferential basal loop and a helical apical loop. Note (1) the transverse basal loop fiber orientation (b–e) representing circumferential fibers, and (2) the right- and left-handed apical loop helix with predominantly oblique fibers, and (3) myocardial fold in (e) showing basal midwall twist to form the apical loop. The unfolded basal loop (d) contains a right segment (RS) and left segment that surround the left and right ventricles. The septum does not have circumferential fibers. The apical loop has helical fibers that form the right-handed helical arm or descending segment (DS) and left-handed arm or ascending segment (AS). The unfolded myocardial band in (e) extends between the pulmonary artery (PA) and the aorta (Ao). Note (a) the intact heart contains a circumferential basal loop wrap that surrounds the apical loop comprising helical fibers; (B) Architectural fiber orientation of (B1) intact heart in upper left with circumferential fibers surrounding the inner helical fibers, (B2) detached circumferential fibers (basal loop) in upper right with predominantly horizontal fibers compared with the conical apical loop containing right- and left-handed helical fibers in a helical design, (c) with these segments super-imposed (top image); when the segments are separated (below), (B3) the right-handed helix or descending segment (lower left) connected to the myocardial fold with oblique fibers aimed toward apex, and (B4) overlying left-handed helix or ascending segment (lower right) with longer oblique fibers coursing toward aorta connection. This fiber orientation is used in all subsequent anatomical drawings.


1183

Fig. 55.5: Conceptual cartoons of myofiber structural orientation from imaging and anatomy reports. The imaging drawing (left) separates the left ventricle into a deep endocardium with right-handed helical clockwise fibers and a superficial epicardium with left-handed helical counterclockwise fibers. There is no circumferential or circular muscle. The anatomical drawing (right) displays similar right- and left-handed helical arms in the deep endocardium and superficial epicardium regions but adds the prominent component of thick circular or circumferential fibers that reflect the “Triebwerkzeug” described by Krehl.4 These circular fibers are considered to be constrictor fibers by anatomists.

(torque) to dominate the overall direction of rotation toward apical counterclockwise rotation14,41,42 (Fig. 55.5). Untwisting was ascribed to endocardial or right-handed helix recoil in an engineering model that also predicts (a) no difference between a cylinder and an ellipse model (as also described by Ingels41 in intact hearts),20,30 and (b) states that both endocardial and epicardial segments cause systolic shortening to bring the base toward the apex.12,15,40,43 Conversely, this analysis employs an anatomically defined structure to define mechanical and timing interdependence of twisting and untwisting, and differs from current state-of-the-art reports. The right- and left-handed helical arms will be called the descending and ascending segments, respectively. Imaging reports using 2D STI recordings describe subendocardial clockwise motion and state the transmural apical region moves clockwise, while the reciprocal stretch of the subepicardium causes the base to move counterclockwise during that interval. These 2D STI observations differ from the MRI evidence of transmural IVC apical counterclockwise motions16,44 (Figs 55.7A to C). This disparity between different recording methods

has been ascribed to lower temporal resolution by the same MRI modality that is simultaneously called “the gold standard” of measurements. An alternate explanation is that both methods are correct, but that this discrepancy may be related to imaging analysis depth as MRI quantifies transmural observations and STI focuses only upon tissue moving in the same observation plane.16,17

DEFINITIONS “Rotation” is the circular or angular movement of the LV about its long axis, and by convention is defined as clockwise or counterclockwise when looking up at the heart from the foot of a supine patient. If the whole LV rotates en masse, there is no torsion. Conversely, if apex and base rotate in opposite directions, then torsion can be assessed by the angular difference between them (Fig. 55.8). “Twisting” describes these differences without reference to a long-axis measurement. “Untwisting” expresses the return of cardiac shape to its initial resting position. “Torsion” defines the difference between the rotation of

1184


Fig. 55.6: Structural reasons for torsion from bioengineering drawings (above) and anatomical structure (below). Comparable findings during torsion development are reported in bioengineering studies under conditions where myocardium structure is displayed as either cylindrical (upper left) or conical (upper right), as the right-handed helical arm or deeper clockwise endocardium and is covered by a left-handed helical or counterclockwise arm. Torsion is described as developing within each arm as shown by the arrows in the cylinder on the right, and each arm develops clockwise and counterclockwise motion as shown on the left. The clockwise layer is R1, counterclockwise layer is R2, and its larger torque causes apical counterclockwise rotation during torsion. Below, the anatomical structure shows a right-handed helical arm with clockwise motion (lower right) and a left-handed helical arm with counterclockwise motion (lower right) and these arms are called the descending and ascending segments of the apical loop. Torsion is described as developing between helices, as the entire right- and left-handed helix move in different directions.

the base and apex of the LV relative to the long axis, exists beyond the interval for systolic ejection, is measured in degrees, and defining its duration is a vital part of its measurement.

NOVEL MECHANICAL AND TIMING INTERDEPENDENCE BETWEEN TORSION AND UNTWISTING Torsion and untwisting are “transmural” rotational movements well seen by MRI.44,45 Mechanistic insight

into why these interweaving circular and helical fiber components exert their dominant “global” action becomes clearer by use of other imaging modalities such as STI, VVI, and sonomicrometer crystals that define “regional” analysis, and simultaneously characterize their timing sequence.17,42,46 Harmonic interaction exists during rotational movement that relates to the coiling and uncoiling actions of responsible muscles; the uniformity of global counterclockwise motion during IVC precedes the apex and base differential motion during torsion, and then recurs during untwisting as a uniform or global


A

1185

B

C Figs 55.7A to C: Motion of apex and base during isovolumic contraction by speckle tracking imaging (STI; upper) and magnetic resonance imaging (MRI) studies. (A) The STI study shows counterclockwise (above baseline) and clockwise motions of the base and apex, respectively, during the isovolumic contraction. The speckle tracking with marker is placed at the left ventricular (LV) endocardial surface (Echopac PC V 6, GE Healthcare, Milwaukee, WI, USA). Tracings from Aman Mahajan laboratory; (B) MRI studies showing global counterclockwise motion of the apex and base during isovolumic contraction in both studies. Tagged MR images were acquired on a 1.5 T whole body MR scanner (Magnetom Sonata, Siemens, Erlangen, Germany) with a temporal resolution of 14 ms. The hatched line following twisting (apex counterclockwise and base clockwise) marks peak apical rotation that exists just prior to the postejection isovolumic interval. Note: apex begins clockwise motion at this stage and prolongation of clockwise base rotation; global clockwise motion occurs during this postejection isovolumic interval; (C) Velocity vector imaging (VVI) short-axis views of endocardial rotational motion of six segments at the apex and base employing the (Sequoia 512, Siemens, Mountain View, CA, USA 4.0 MHz transducer) derived from three-dimensional (3D) images displays counterclockwise motion of the apex and base during the isovolumic contraction (IVC) phase. The hatched purple lines show both the end of the IVC phase where AVo is aortic valve opening, and the separated purple hatched lines between AVc or aortic valve closure and MVo or mitral valve opening show the postejection isovolumic interval.

clockwise movement.16 Consequently, despite emphasis upon their interplay during torsion and untwisting,14,15,47,48 understanding their interweaving muscular interactions during the IVC interval is fundamental requirement in order to understand mechanistic reasons for torsion and untwisting motions. Moreover, untwisting cannot begin if torsion is prolonged.

THE NORMAL HEART The Left Ventricle Isovolumic Contraction Ventricular narrowing, elongation, and counterclockwise net rotation characterize the pre-ejection phase.16,17

1186


Fig. 55.8: Ventricular torsion displayed by speckle tracking imaging (STI) on left side (From Aman Mahajan laboratory) and magnetic resonance imaging (MRI) on right side (From Jurgen Hennig laboratory), where twisting motions between the left ventricular apex and base are displayed. STI study shows counterclockwise (above baseline) and clockwise motions of the apex and base, respectively, during the cardiac ejection. The speckle tracking with marker is placed at the left ventricular (LV) endocardial surface (Echopac PC V 6, GE Healthcare, Milwaukee, WI, USA). MRI phase contrast velocity mapping (tissue phase mapping) of systolic ejection cardiac frames with a temporal resolution of 13.8 ms during free breathing in a healthy volunteer shows arrows that demonstrate clockwise (marker to right) and counterclockwise (marker to left) directions of transmural twisting motion during the short-axis view.

Sonomicrometer crystal recordings during this 50-ms interval display the contributions of individual muscle masses by documenting that (a) the right and left sides of the circumferential circular fibers shorten almost simultaneously (10 ms delay between right and left segments of basal wrap)16,49,50 with the subendocardial descending segment helical fibers during IVC, and (b) there is no ascending segment helical subepicardial fiber shortening during that interval.49,50 STI measurements of subendocardial shortening and lengthening during preejection systole provide further evidence of stiff outer shell dominance.13 They show that the initial longitudinal shortening is followed immediately by apical lengthening, as the circular base compresses the inner helix; shortening would otherwise occur if the co-contracting descending segment was dominant. Moreover, the overlying noncontracting ascending segment fibers stretch during ventricular elongation,42,51 so that they cannot be responsible for global counterclockwise rotation of the cardiac base during the pre-ejection interval. Previous

descriptions of fiber orientation of the underlying muscle during IVC may be misleading, because only oblique helical fibers were measured at the selected sampling;51 this analysis did not evaluate the circumferential basal segment, whereby their horizontal orientation49,50 exerts the compressive force that was just described. MRI evidence of global counterclockwise motion contradicts STI documentation of clockwise motion by the right-handed helix or descending segment, and VVI recordings derived from real time 3D echocardiography in Figure 55.7C confirm this counterclockwise movement. Global counterclockwise movement must arise from the governing circumferential muscle fiber, because the clockwise motion arising from descending segment is not dominant. Anatomical analysis of circumferential muscle mass dimensions16 shows why the thicker, left-sided basal circular fibers exert the mechanical advantage causing the dominant counterclockwise motion that accompanies the ventricular narrowing that exists during LV cavity compression (Fig. 55.9A). Moreover, recent VVI recordings show that as the compressed or narrowed LV chamber develops pressure, the blood flow velocity from apex to base closes the mitral valve,16 and there is simultaneous expansion or rightward motion of the upper portion of noncontracting ascending segment fibers within the septum (Fig. 55.9B). This rightward movement, which resembles the bulging of an aneurysm, occurs because of the presence of noncontracting or relaxed ascending segment fibers within this subaortic valve region that is anatomically uncovered by the contracting right-sided deep descending segment fibers, as shown in Figure 55.9B. Rotational motions during IVC similarly relate to dominant interactions because (a) the coiling of basal loops circular fibers that causes cardiac compression, simultaneously produces a net counterclockwise global movement that overcomes clockwise rotation caused by the descending segment fibers as intraventricular pressure rises before ejection, especially because (b) the ascending segment muscle is not shortening, so that it cannot contribute to pre-ejection counterclockwise basal rotation. Most importantly, the clockwise descending segment motion during IVC produces a persistent clockwise rotational motion that continues as torsion develops during the next phase of ejection.

Torsion The presystolic isovolumic interval is followed by ventricular ejection, whereby torsion develops as the


1187

A

B Figs 55.9A and B: (A) On the left side is cranial view of the model of the helical ventricular myocardial band showing how the circular and circumferential fibers or basal loop surrounds and embraces the conical right- and left-handed helix or apical loop. Note that (a) circumferential fiber muscle thickness is greatest in the left component or segment, and thinner in the right component or segment and (b) there are no circumferential fibers in the septum. On the right side are VVI images of isovolumic contraction (Sequoia, 512, Siemens, Mountain View, CA, USA; 4.0 MHz transducer), where there is shortening of the entire circumference of basal loop, and of the righthanded helical armor descending segment. No left-handed arm or ascending segment shortening occurs, yet right-sided upper septum motion exists in area of uncovered noncontracting left-handed helix or ascending segment as shown in B images; (B) Topographical view of septum architecture in the wrapped heart where the right ventricle is intact (left side) and unwrapped form where the circumferential fibers are separated. Note that the apical loop has a septum segment above the overlap of right- and left-handed helical fibers, where the left-handed arm or ascending segment is the only muscle mass. This segment does not shorten during the isovolumic contraction, and is the only segment that shortens during the postejection isovolumic phase (Fig. 55.8A, left panel and Fig. 55.11B, in “a” figure).

1188


LV cavity shortens and its wall thickness increases due to deformation of all co-contracting circular and helical fibers, as the ascending segment begins to contract.49,50 MRI and STI images13,15,16,44,46,52 document that the apex and base twist in different directions, and VVI recordings16 show consistent inward systolic subendocardial motion at the apex, midwall, and base to provide evidence that contradicts theoretical concepts that counterclockwise twisting exists within the subendocardial muscle.14,15 Compression is a central feature of the torsion sequence as the LV shortens and twists to eject, because such narrowing reflects the functional contribution of circumferential or circular fibers, as well as being due to helical fiber deformation. Conversely, shortening reflects the principal coiling motion of oblique helical fibers within the descending segment. The initial phase of torsion furthers ventricular compression without imparting substantial shortening, as the ascending segment fibers only begin to contract at this beginning stage. VVI studies during this phase at the onset of torsion are shown in Figure 55.1 (occupying approximately 50 ms or approximately 20% of the torsion interval at 72 beats/min), as they provide insight into why the circular fibers remain dominant as torsion starts. Figure 55.10 displays motion immediately following the QRS wave on the electrocardiogram by showing that (a) the septum twists (different motion of its basal and apical components) as its inward velocity vector reflects descending segment helical shortening, while the simultaneously outward velocity vector motion is caused by the ascending segment helical arm that is not covered by circumferential muscle, (b) minimum shortening occurs because the dominant circular muscle mass that occupies the upper lateral ventricular wall becomes the governing force of narrowing or compression, and thereby overrides the counterclockwise motion of the underlying oblique or ascending segment lateral LV free wall component, whose shortening has just begun. Figure 55.1C also shows that initiation of clockwise basal motion is delayed due to ongoing counterclockwise motion of the circular fibers that started during IVC, and (c), inward movement persists within the lower lateral wall, because no circular fibers exist in that region (Fig. 55.10). The next phase of torsion during ejection involves longitudinal shortening and reflects its most important component. Helical fiber dominance governs this motion, even though there is simultaneous compression arising from deformation of co-contracting circular and helical fibers, as well as from narrowing by the more horizontal

pathway achieved by the outer ascending segment helical arm as the entire helix coils.16,17 The figure-of-eight spiraling arms of these shortening vectors dominate (Fig. 55.11A), as the descending segment fibers exert a downward velocity vector direction toward the apex during their contraction, while the ascending segment helical fibers are pulled downward to follow a downward velocity vector toward the apex caused by dominance of the descending segment; the upward motion of the ascending segment only becomes uncovered during the postejection isovolumic phase, where the antagonistic descending segment stops contracting. Consequently, shortening forces overcome the predominant compressive action of the circular fibers that existed when torsion was initiated. There is complementary action between the reciprocally helical coiling forces that become maximal at the apical vortex,53 because the circumferential basal fibers act as a buttress to prevent explosion or unlimited expansion of the vortex forces of helical fibers basal components as they develop reciprocal outward forces to balance the downward motion toward the apical vortex (Fig. 55.11B). From a rotational aspect, the torque from the larger curvature of the ascending segment helix rotates the apex counterclockwise, while the more forceful strain in the descending segment helical fibers16,36 continues the clockwise rotation of the base that began during the IVC. The extent of deformation and strain increases toward the LV apical vortex, which is formed by the helical fibers that exist without any surrounding circumferential muscle at the apical region.17,54 The endocardium of the entire septum, including its apex, midwall, and base, displays a consistent leftward motion16 to provide evidence that contradicts suggestions of separate torsion development within the “subendocardial” layer and the “subepicardial” layer.14,15,40 Instead, torsion and shearing relate to the entire descending segment or right-handed helix rotating clockwise and to the entire ascending segment or lefthanded helix rotating counterclockwise (see Fig. 55.6).

Postejection Isovolumic Phase The isovolumic interval follows ejection and is characterized by untwisting, lengthening, and widening.16,17 This interval was previously called the isovolumic relaxation phase (IVR), but ongoing shortening of the ascending segment continues (albeit at a reduced force so that no ejection occurs), so that the term postejection isovolumic interval is a more precise description. The lengthening and widening components are 2D echocardiography


observations that do not define the 3D geometry required to maintain a constant volume. Insight into this geometric change is provided by echocardiography studies that document how the mitral annulus becomes less oval,55 thereby explaining how an unchanged volume is maintained as the heart lengthens and widens during this interval. The reciprocal relationship of contributions from circular and helical muscles becomes revealed by comparison of their pre and postejection isovolumic volume interactions. Before ejection, the entire circumferential muscle and only the descending segment helical arm shorten, without shortening of the ascending segment helical arm. In contrast, during the postejection isovolumic phase, shortening stops in the left and right segments of the circular muscles and in the descending segment, but continues in the ascending segment. There is normally a 80- to 90-ms “timing hiatus” between the cessation of the descending segment shortening and the time when the ascending segment stops shortening (Fig. 55.13A). Disturbance of this normal relationship during torsion affects untwisting because apical untwisting cannot begin if torsion is extended by prolonged descending segment coiling. Recoil is determined by when shortening stops. Regional and global motion depends upon the dominance of recoiling contributions of the interweaving circular and descending segment arms of the helix. This recoil process is attributed to expansion of the Titin and collagen pathways that were compressed during ejection.56 During the isovolumic phase, rotation during recoil reflects the dominance within the overlapping circular and helical muscle groups, because the ascending segment is still shortening and thereby cannot contribute to this process. Cardiac spatial configuration is a vital factor in the untwisting process because the LV wall would otherwise implode if only helical fibers caused this untwisting motion that precedes suction during rapid filling. This dynamic collapse is prevented by the support of the stiff outer shell formed by circular fibers that maintain a circumferential buttress (Fig. 55.11B). The interplaying forces of three sets of muscle motions determine the net or global clockwise rotation of the apex and base that exists during untwisting. First, the ascending segment cannot be responsible because it contributes an ongoing counterclockwise motion as it continues to shorten, but with diminished force during that interval.36,49,50 Second, the descending segment arm recoils counterclockwise, a motion that contrasts with its clockwise movement

1189

during torsion.16 Third, the circumferential or basal loop contributes a dominant clockwise motion, which of course contrasts to its counterclockwise movement during the IVC phase; ventricular widening is also caused by these recoiling circular fibers. Lengthening is evident from the elegant studies of Karwatowski,57 who used MRI and echocardiography to demonstrate that isovolumic long-axis lengthening preceded flow across the mitral valve by 46 ms. Lengthening during untwisting is determined by both the left- and righthanded arms of the helix or the ascending and descending segments of the apical loop. One component is the ongoing contraction of the ascending segment that had become more spiral during torsion. The helical coil becomes more taut, so that this segment becomes thicker and straighter (thus longer) when the counterforce of the right-handed arm becomes removed after its shortening stops.16 In nature, this resembles the mechanisms within the snake, which elongates before striking due to differences in the contractile sequences in paraspinal muscles (Figs 55.11A to C). The second lengthening component involves returning the recoiling right-handed helix or descending segment to its neutral and thus uncoiled longer helical position (Fig. 55.11C). The untwisting sequence during the postejection isovolumic phase mirrors torsion by having two components. The first phase begins just before the aortic valve closes57,58 and is characterized by reduced torsion and continued shortening as the ascending segment continues to shorten (Fig. 55.12A). Moreover, VVI demonstration that the ascending segment arm’s directional vector points toward the apex does not contradict our prior suggestion that the ascending segment exerted an upward force. Instead, this force is overcome by the dominant righthanded arm during torsion.16 An intriguing imaging parallel exists between the initial phases of IVC and untwisting (Figs 55.8A and 55.12B in its left panel), whereby the same VVI image results are related to entirely different causes. During untwisting, the early appearance of lack of significant motion of the lateral wall and lower septum relates to their absence of contraction, whereas this same image reflects shortening of the circular muscle and descending segment during IVC. The upper septum beneath the aortic valve displays right-sided and downward motion during untwisting that reflects the counterclockwise motion from ongoing ascending segment shortening. In contrast, this right-sided vector during IVC reflects the bulging of this noncontracting

1190


Fig. 55.10: Beginning of torsion (upper left) with co-contraction of base and entire helix. There is essentially no longitudinal ventricular shortening at this time. Note (a) twisting septum with upper septum showing left-sided motion of the right-handed arm of the descending segment and lower septum, and lower lateral wall has right-sided motion of left-handed arm or ascending segment, and (b) upper lateral wall has essentially no motion as it is compressed by shortening circular basal muscle, which does not exist in the septum, and (c) the lower lateral wall has no circumferential compression and shows leftward motion of left-handed arm or ascending segment. Slightly later in torsion (upper right), with more twisting of septum, and increased left-sided motion of lateral wall that is occupied by the more fully contracting left-sided arm or ascending segment. The lower images show the responsible architecture, whereby the lower left shows the wrapped heart, where the uncovered left-handed helix displays more prominent counterclockwise motion. The lower right displays unwrapped heart to show how the circumferential muscle covers the same upper lateral wall to exert a compressive force and limit early rightward counterclockwise motion.


A

1191

B

C Figs 55.11A to C: (A) Velocity vector imaging forces during maximal torsion during ejection as longitudinal shortening occurs. Vector angulation is directed toward the apex, as the helical left- and right-sided arms dominate to change force direction toward the apical vortex, despite ongoing circumferential or circular muscle shortening; (B) Drawing of simulated cardiac anatomy with circumferential wrap and internal helix (lower left) with spiral motion for ejection (in center) and suction (lower right). The outward spiral forces with an apical vortex during ejection would expand the basal wall laterally to potentially cause explosion. Lower right shows suction where inward forces at the base would cause implosion. This circumferential wrap at the base becomes a buttress to prevent these events, and this configuration resembles a gothic cathedral (upper center) where the buttress protects the downward forces of the dome from loss of the base due to downward forces from the tip at the peak of the dome; (C) This drawing shows normal anatomy (upper left) with right and left segments of basal loop [right segment (RS) and left segment (LS)], and right and left helical arms of apical loop or descending and ascending segments [descending segment (DS) and ascending segment (AS)]. The bottom shows the coils in the right-handed helix arms in diastole, ejection, and isovolumic phase. Note that (a) both shorten during ejection, but the descending segment is stronger, (b) ascending segment becomes more horizontal as spiral shortens, and (c) ascending segment continues shortening during isovolumic phase and causes elevation or lengthening. This action mirrors cobra shown in upper right that lengthens as its spiral becomes elongated in its pose before striking (Fig. 55.11A).

region due to increased intraventricular pressure (Fig. 55.8A compared to 55.12B in its left figure). The second untwisting component involves the prominent left-sided vectors (Fig. 55.12B, panels b and c) that match similar rotational motions recorded by MRI and STI imaging methods.15,44,46,59 No flow crosses the mitral valve during this counterclockwise movement,

even though the valve cusps may be open. Untwisting reflects the opposite of twisting, yet global motion shows no differential differences between the apex and base, as both segments rotate clockwise (MRI image). Consequently, the term “untwisting” is not matched by global differential rotational action. A better term may be either unwinding, uncoiling, or recoiling as these terms do

1192


A

B Figs 55.12A and B: (A) On the left, tracings of endocardial and epicardial sonomicrometer crystals placed into the fiber orientation pathways of the right- and left-handed helix, or descending and ascending segments in anterior myocardium of open-chest pig. The solid line shows the beginning and ending of the right-handed helix shortening, and the hatched lines show the left-handed helix or ascending segment. The postejection isovolumic phase (within yellow color overlay) shows (a) approximately 80 ms time hiatus, and (b) lengthening of the right-handed helix as the left-handed helix or ascending (Asc.) anterior fibers are still shortening; the left ventricle (LV) pressure and dP/dt tracings indicate the timing. On the right is unfolded myocardial architecture showing left- and right-handed or ascending and descending segments of the helical ventricle, surrounded by the circumferential muscle of the basal loop. Note that (1) central ventricular cavity is composed of overlapping left- and right-handed helices or ascending and descending segment fibers in the septum region, (2) left-handed helix wraps around and overlaps the right-handed helix in septum, and (3) absence of overlap in the lateral wall, which is composed of the left-handed helix or ascending segment. The lack of overlap in the left-handed helix or ascending segment also occurs in the septum, below the aortic valve, as displayed in Fig. 55.9B; (B) In (a), beginning of “postejection isovolumic phase” with right-sided motion of the upper septum, where there is ongoing shortening of the left-handed arm or ascending segment without overlap of right-sided arm or descending segment. Simultaneously, there is essentially no motion of the lower septum or lateral wall, where the circular and right-handed arm and descending segment fibers just stopped shortening. In (b), slightly later in postejection isovolumic phase, there is left-sided motion of the septum and lateral wall due to recoil of the circumferential or circular basal muscle, and the upper septum now shows similar left-sided movement despite the ongoing shortening of the left-sided arm or ascending segment that just showed right-sided motion before these recoiling forces became dominant. In (c), end of postejection isovolumic phase with both septum and lateral wall showing left-sided movement as dominant recoil exists in the circumferential or circular base, which thereby counteracts the simultaneous counterclockwise recoil of both the right-handed helical arm or descending segment and ongoing shortening with counterclockwise motion of the left-handed helical arm or ascending segment.


not require the differential action that would be needed if untwisting is used. The dominance of recoiling by circular or circumferential fibers that cause this counterclockwise motion parallels how these circular fibers also cause dominant global counterclockwise rotation as they coil during the IVC interval. Consequently, a balance becomes apparent between fiber orientation and rotational motion before and after torsion. The circumferentially controlled global motions before and after torsion effectively surround the twisting motions of the differential clockwise and counterclockwise rotations of the base and apex during torsion, which are principally determined by the helical fibers. Untwisting during elongation sets the stage for rapid filling by creating a deceleration of ventricular pressure and circumferential force that creates a potential vacuum that causes suction after ventricular pressure falls below atrial pressure.16,57 The causative mechanism of untwisting during rapid filling differs from recoil of the noncontracting circumferential fibers during the postejection isovolumic phase, and relates to recoil of the left-handed arm fibers that starts immediately after they stop shortening. Consequently, the left-handed helix or ascending segment cannot be the cause of the initiation of untwisting during elongation59 because it maintains strain, continues to shorten,16 and its counterclockwise motion is maintained until its contraction stops. Under normal circumstances, such ascending segment shortening is normally called “post-systolic contraction”, a term that shows why the term “IVR” is inaccurate.16 This early postejection time interval for post-systolic contraction is extremely important in determining the interdependence of torsion and untwisting, because prolonged descending segment shortening is caused by the right-handed helical arm due to a spectrum of causes, and will interrupt the onset of untwisting and interfere with rapid filling patterns that are subsequently considered under clinical implications.60–63 The aforementioned temporal and mechanical factors underlying untwisting cause a dynamic geometric change in ventricular size and shape that result in a series of imaging and hemodynamic changes that include measuring the rate of untwisting48,59 as well as tau (change in time related to change in deceleration in LV pressure)64 and development of an intraventricular pressure gradient that becomes maximal immediately after the rapid filling that follows the postejection isovolumic interval.65 Each factor is a result of the functional geometric change that produces such measurements.

A

1193

B

Figs 55.13A and B: (A) First phase of rapid filling with elongation (note apical lengthening) and further leftward motion of the septum and lateral wall as there is recoil of the left-handed helical arm or ascending segment, together with termination of recoil or the circumferential or circular base and right-handed arm or descending segment whose forces interacted during the preceding postejection isovolumic phase; (B) Completion of the rapid filling phase, whereby increasing ventricular volume is the dominant force as the left ventricle (LV) chamber further lengthens and widens. Velocity vector imaging (VVI) displays expansion and outward velocities because filling forces overcome recoil action in septum and lateral wall.

Rapid Filling Untwisting has two components, as the initial unwinding occurs during the postejection isovolumic interval and is dissociated from the untwisting, causing rapid filling but the causes are tightly interrelated.66 Early untwisting during the postejection isovolumic interval is the reason for subsequent suction, despite this temporal separation; recoil continues from a different cause (the ascending segment) during the subsequent phase of rapid filling that develops after ventricular pressure falls below atrial pressure (Figs 55.13A and B). The first phase of untwisting is characterized by transmural clockwise motion that is initially caused by dominant recoil of circular muscle during this postejection isovolumic interval. The second phase develops from elastic recoil of compressed titin coils within the left-handed helix or ascending segment fibers. The interaction of these dual recoiling forces is critical for suction, because 50–60% of untwisting normally occurs before the rapid filling phase.64,67 Moreover, a fundamental component relates to the normal 80 ms timing hiatus between the completion of shortening of the descending segment and the later completion of shortening in the ascending segment. Suction increases if inotropic drugs

1194


enhance isovolumic phase untwisting,48,59 or diminishes if untwisting is delayed by prolonged torsion when shortening of the descending segment extends torsion during this “temporal hiatus interval.”16,63 Unwinding of the apex to return to its original position in order to create suction for rapid ventricular filling requires relaxation of all muscle segments, so that the isovolumic interval untwisting component becomes an essential prelude to this process. Conversely, prolonged descending segment shortening allows ongoing torsion during the isovolumic interval, thereby diminishing this response, retards LV pressure deceleration, reduces ventricular compliance, and impairs the 50–60% of filling that normally occurs during this period.67 Augmented filling pressures are then needed to achieve proper enddiastolic volume after cessation of the apical clockwise unwinding, in order to stretch the LV satisfactorily during the later slower or passive filling phase.

THE SEPTUM The ventricular septum is a thick structure composed of discrete muscular bands that separate the LV and RV. The septum comprises approximately 40% of ventricular muscle mass and contributes to biventricular cardiac function.68 Analysis of this structure/function relationship requires a full understanding of how existing normal anatomical form translates into hemodynamic performance. Satisfactory accomplishment of this task shall answer the 1790 supposition of Weber,19 who indicated that actions of muscular heart would not be understood until the muscle bundles of the septum are clarified. Our initial experimental evaluation of septal structure/ relationships was acquired by use of sonomicrometer crystal measurements that demonstrated how fiber orientation determines the maximum rate of systolic shortening. Findings validated the hypothesis that the configuration of septum anatomy conformed to the descending and ascending segments of the HVMB, as described by Torrent-Guasp11 (Figs 55.3 and 55.4). This spatial composition has been recently supported by DTMRI recordings (Figs 55.14A to C).25,26 Oblique fibers of the endocardial regions of the left and right sides of the septum displayed the same functional characteristics that exist within in the free LV wall, thereby confirming the spatial structural configuration required for development of twisting.

The interaction between noninvasive methods and structure is enhanced by conventional low-resolution ultrasound imaging of the working ventricular septum, which has previously identified a hyperechogenic “septal line” that matches the septal separation line, which runs in a basal–apical direction (Figs 55.15A and B)18 as demonstrated by postmortem contrast tomography studies by Lunkenheimer et al.27 Highresolution ultrasound imaging allows identification of the structural and functional separation of the ascending and descending septum components along the previously observed “septal line”, along with temporal and sequential movement of these muscle layers toward the respective ventricular cavities (Figs 55.16A and B). Visualization of different fiber orientation in the working heart using highresolution echocardiography strongly supports the helical anatomical models displaying the muscle bands that form the ventricular septum and free LV wall. Figure 55.17 displays similar functional contractions of the descending and ascending segments that are similar between these structures. Recent animal studies in the working heart, using higher magnification of this septum midline in porcine and rabbit models, document that a space exists between the edges of the septal line (Fig. 55.16B).18 The line is approximately 100 microm (0.10 mm) wide, and its thinedge components attach to the overlying ascending and descending segments of the septum muscle. The septum muscle on either side of this line in the working hearts shows a relative uniformity that depends on the echocardiogram probe placement position in relation to fiber orientation planes that pass along or across working muscle (Fig. 55.16B). Further analysis of the midseptum line demonstrates that the space between its edges (a) is retained during systole (when intramyocardial vessels are collapsed by the surrounding contracting muscle); (b) is unchanged during early diastole (when flow through vessels is greatest and would expand the space if it was vascular); and (c) becomes nearly obliterated when function of the overlying ascending and descending segments is removed during cardiopulmonary bypass by inducing ventricular fibrillation, and completely obliterated or cardiac arrest by cardioplegia (Fig. 55.16B). The space between this line conforms to the pathway followed by Torrent-Guasp during his cardiac dissection as he separated the ascending and descending loops during postmortem analysis. Most importantly, the collapse of


1195

B

A

C

A

Figs 55.14A to C: (A) Fiber orientation relationship of the septum, composed of oblique fibers that arise from the descending and ascending segments of the apical loop, surrounded by the transverse muscle orientation of the basal loop that comprises the free right ventricular (RV) wall. Note the conical arrangement of the septum muscle and the basal loop wrap, forming the RV cavity; (B) (a) Diffusion tensor magnetic resonance imaging (DTMRI) studies, where water is diffused parallel to fiber orientation, showing a helical positive or right-handed helix or clockwise (red) and negative or left-handed helix or counterclockwise (yellow) muscle of myofibers reflecting circumferential or horizontal with a zero helix angle. Note absence of circumferential or circular fibers in the septum, and how these zero angle helix fibers encircle the left and right ventricles. (c) Dissected heart showing the circumferential or basal loop fibers encircling the left and right ventricles that are not present in septum, and overlapping left and right helical fibers of the apical loop in septum; (C) Diffusion tensor magnetic resonance imaging (MRI) from the work of Zhukov and Barr26 showing the helical inner or endocardial (clockwise) and outer or epicardial (counterclockwise) fiber orientation (in purple and blue colors) and a central left ventricular (LV) free wall that is white to reflect a more horizontal or very small angle pitch that does not involve the septum.

B

Figs 55.15A and B: (A) Cross-section images demonstrating the oblique crisscross endocardial and epicardial fibers contained within a circumferential midseptal wall; (B) Computed tomography scans demonstrating the interweaving collagen support of the connective tissue skeleton that is likely the scaffold for reciprocally oblique septal muscular fibers. Note the space between the two septum regions.

1196


A

B1

B2

B3

B4

Figs 55.16A and B: (A) Low- and high-resolution echocardiogram showing the mid-hyperechogenic and midseptal line; (B) High-resolution ultrasound image of the septum at the base of the heart acquired using high ultrasound transducer frequency (12 MHz). Septal images showing a bilayer structure with an inner dimension of 100 to 150 mm. B-mode or echocardiographic pattern of the septum on either side of the septal bilayer is different, demonstrating the different directionality of the myocardial fibers on the respective sides of the septum. The septal bilayer is recorded during a normal cardiac cycle, during ventricular fibrillation, and during cardiac arrest.


1197

Fig. 55.17: Comparison of ultrasonic crystal tracings of descending and ascending segments of left ventricular (LV) free wall, and M-mode and Doppler M-mode imaging of the septum. The beginning and end of descending segment shortening and motion (solid lines), and the ascending segment (hatched lines). Strain in the right (red) and left (blue) sides of the septum is noted in systole. M-mode shows displacement of the left and right sides of the septum toward their respective ventricular chambers. Note the delay of initiation of ascending segment and right septal motion and lengthening of descending segment during phase after ejection and continuing displacement of the right side of the septum toward the right ventricular (RV) cavity, despite the beginning of LV cavity expansion. (LV: Left ventricle).

this space between the border edges of this midseptal line precisely reflects the conditions encountered by the anatomist or pathologist in the cadaver or biopsy specimen. Structural differences between dead vs live conditions can lead to artifacts, but matching form to performance must remain the goal of the functional anatomist. We concur with problems related to cadaver dissection limitations that were suggested by Grant,6 and Lev and Simkins,7 and that are now supported by Anderson et al.8 An example is the incorrect posterior papillary muscle position that accompanies the myocardial band during

Torrent-Guasp’s unfolding diagrams.50 Torrent-Guasp et al. realized this error when they were made aware of the 1971 functional studies by Armour and Randall.69 Their subsequent dissections display the proper location, and they encouraged valid correlation of structure and function during efforts to understand architectural reasons for living heart motions. The physiological implications of these observations is that the oblique nature of the septum structure is a vital component needed for generating the twisting motion required for efficient ventricular ejection against

1198


increased peripheral vascular resistance. In contrast, constriction or bellows action is the predominant function of the basal loop as the result of its predominant transverse fiber orientation, because its circular fibers surround the LV and RV septum. Consequently, rightsided heart function may become impaired after loss of sequential septum contraction with attendant pulmonary hypertension, an effect that sometimes follows septum hypokinesia or akinesia or dyskinesia in cardiac surgical procedures with impaired myocardial protection,70 or after temporary ischemia, or when the septum is stretched after LV or RV volume overload. Conversely, recognizing and using knowledge from this form–function relationship has resulted in developing innovative RV reconstructive procedures that restore the septum into the midline position, recover its twisting action, and result in favorable clinical outcomes.71

THE RIGHT VENTRICLE RV architecture involves two components. First, the free wall is predominantly composed of a basal loop containing transverse fibers, which constrict or compress the chamber. Second, the septum contains helical fibers with an oblique orientation that cause a twisting movement; there is no septum transverse component (Figs 55.18A and B). Comparison of RV and LV architecture reveals marked differences because the RV has no global helical configuration, even though its outflow tract free wall contains oblique ascending segment fibers that TorrentGuasp termed aberrant fibers.11 The septum is a central biventricular helical structure, rather than a LV structure.72 The interaction of its free wall’s predominant transverse fibers and septum’s oblique fiber orientations determine RV function, which was inaccurately called a bellows action due to (a) free wall’s horizontal fibers that constrict or compress the RV chamber against the septum73 and (b) the incorrect notion that the septum was a LV structure.72 A twisting action is needed, especially against increased pulmonary vascular resistance (PVR), and that movement is provided by the septum’s helical fibers that becomes quantified by its shortening and lengthening movement. Prior concepts that RV has a bellows-like action are related to measurement from septum to free wall dimension by ventriculogram,73 but these 2D recordings can only demonstrate narrowing, shortening, lengthening, or widening movements. In contrast, 3D measurements

are needed to define the septum’s twisting capacity. An example of this interface is shown by the way that circumferential basal loop constricts the RV during IVC, an action that precedes the septal shortening that occurs during ejection when afterload is encountered. Wiggers in 191474 showed that IVC compressive movements were unaltered by RV afterloading because the pulmonary valve did not open during this interval. In contrast, inotropic drug stimulation directly affected circumferential free wall muscle contraction to accentuate function.74 The interaction between septum and free wall performance has been experimentally tested by investigators who demonstrated that RV performance was not significantly impaired by either cauterization of the entire RV free wall,75 its replacement by a semirigid patch material,76 or regional ventricular fibrillation after its isolation,77 so long as the septum was intact. Conversely, RV failure developed if the septum was either cauterized, made ischemic by further dye embolization after right coronary artery occlusion, or damaged by pulmonary hypertension;78 each intervention deteriorated performance by interrupting the natural septal wringing motion.

OTHER CONSIDERATIONS Subendocardial Muscle; Correct Anatomical Location But Architectural and Functional Confusion Subendocardial muscle mass surrounds the LV inner surface, and drawings14,15,40,51 (Fig. 55.19) left side of the transmural ventricle imply a circumferential line that bisects the LV wall to separate the deeper oblique clockwise fibers of the descending segment or right-handed helix from the overlying counterclockwise ascending segment or left-handed helix that occupies the outer LV shell. In contrast, anatomical studies show that different parts of right- and left-handed helices form the circumferential subendocardial muscle.10,11,31,32 This difference conveys a different functional effect, as previously described during cardiac motions of the normal heart. The dissected or unraveled cardiac architecture shown in Figs 55.4 and 55.9 shows that the upper septal oblique orientation differs from reciprocally oblique fibers of the lower septum, and that the oblique lateral ventricular wall subendocardial fiber arrangement mirrors that of the subepicardium, because there is no overlap of descending and ascending segment helical fibers (Figs 55.9 and 55.10).


A1

A2

A3

A4

B

VVI recordings in Figures 55.9A and 55.12B demonstrate dissimilar subendocardial motion during the time frames of IVC, twisting for ejection, and untwisting before rapid filling. Presumptions of subendocardial function that are only based upon bioengineering models containing a uniform or homogeneous inner shall wrap40 may provide

1199

Figs 55.18A and B: (A) Model and anatomical preparations showing the orientation of the ventricular myocardial band of the (A1 and A2) intact heart and (A3 and A4) after exposing the septum by unfolding of the right ventricular (RV) free wall. Note the similar configuration of the septum and left ventricular (LV) free wall composed of the ascending segment of the apical loop; (B) Anatomical unwrapping of the right segment of the basal loop, which surrounds the septum composed of the helical fibers of the descending and ascending segments of the apical loop.

confusing conclusions. Dynamics of the anatomically visible subendocardial muscle are linked to both an architectural configuration that evolves from its left- and right-handed cardiac helical form, as well as from how the wrapped circular muscles within the upper LV influence its motions. The global counterclockwise rotation during IVC,

1200


Fig. 55.19: The left drawing shows a bioengineering concept of circumferentially overlapping endocardium and epicardium, whereby the endocardium reflects the right-handed helical arm and surrounds the left ventricular (LV) inner surface. The right architectural reflection of the anatomical endocardium shows that it is formed by both the right- and left-handed helical arms, and has fiber pathways that have both clockwise and counterclockwise directions. This anatomy is described in Figure 55.10.

despite clockwise motion of the endocardium becomes explained by such insight into powerful circular muscle during normal cardiac architecture.

Torsion and Untwisting/Preload and Afterload Relationships Changes in torsion and untwisting within normal conical hearts has been defined in regard to alterations in preload, which increases them due to volume dependency, and raised afterload that increases torsion while reducing untwisting.15 Conversely, dilated and failing hearts have a more spherical form and exhibit completely different torsion and untwisting responses following similar hemodynamic loading alterations.79 Consequently, LV geometric alterations influence motion observations in a manner that is independent of loading conditions, because cardiac fiber orientation is primarily responsible for such rotational actions.80,81 van Dalen reinforced this observation by showing that LV sphericity index is the strongest independent predictor of apical rotation and twist when comparing normal subjects with an elliptical cardiac shape against a cohort with dilated cardiomyopathy.79 Figs 55.20A and B shows such architectural changes when the conical form becomes spherical, and implies that

changing the natural 60° angulations of the right- and lefthanded helical components toward a more horizontal82,83 configuration will geometrically alter functional twisting and untwisting. For example, Borg recently examined changes after increased preload and reduced afterload in patients with mitral insufficiency (whose regurgitation causes these intrinsic spherical ventricular shape changes) and demonstrated decreased torsion and reduced untwisting.84 Moreover, initiation of the untwisting movement began 23 ms before aortic valve closure. This reliable echocardiographic finding, thereby poses a series of questions about responsible muscular mechanisms that produce such reproducible changes. Untwisting normally begins during the postejection isovolumic phase, yet mitral valve insufficiency continues after aortic valve closure58 to thereby support the functional role of ongoing ascending segment contraction during an interval that previously was called IVR.

Mitral Valve Opening Relationships with Untwisting Echocardiographic calculations of torsion and untwisting are traditionally related to mitral valve opening (MVO) alterations.15,59,85 This terminology is based upon Doppler


A

1201

B

Figs 55.20A and B: Comparison of fiber orientation in the normal heart (above) and the dilated or spherical form (below) where there is detachment of the circumferential or basal loop with horizontal fibers, and exposure of the normal and spherical configuration of the right- and left-sided arms of the helical structure. Note that the normal 60° fiber orientation becomes more horizontal in the spherical configuration and this angulation begins to resemble the more transverse fiber pathways of the circumferential or basal loop.

inflow and outflow recordings, rather than conforming to knowledge of the separation of the mitral leaflets, which provide the only valid confirmation of MVO. Lee in 199058 called this MVO observation “the mitral valve artifact that correlates with the E point in the mitral echogram, but is unrelated to actual mitral valve opening”. Moreover, concepts of untwisting existing during the “IVR interval” that are based upon this MVO observation need reevaluation, because subepicardial muscle continues to contract and myocardial strain is maintained during this phase.16,59 Untwisting during the postejection isovolumic phase is due to uncoiling of the transversely oriented circumferential muscle surrounding the cardiac base that both rotates and houses the helix from which the papillary muscles arise. Ventricular untwisting caused by these horizontal fibers may simultaneously open the mitral valve leaflets by changing papillary muscle position, and thereby may explain Lee’s 1990 findings.58 Moreover, untwisting simply cannot start if there is ongoing torsion, as exists in a spectrum of diseases to be subsequently discussed. Mitral valve inflow (MVI) is a more accurate term than MVO, because this term dissociates the earlier existing anatomical observation of leaflet separation from a later flow effect that is only initiated during the rapid filling phase.

Clinical Implications Recognizing how the interdependence of torsion and untwisting relates to underlying mechanics and

timing provides insight into how measuring torsion’s peak, velocity, or rate and duration uncovers their interconnection. Torsion duration is an essential feature that improves a fuller understanding of untwisting, because its knowledge integrates with the vital “timing hiatus” that exists between the end of descending and then subsequent ascending segment shortening. Untwisting is unchanged if this interval mirrors the approximately 80-ms interval existing at normal heart rates. Conversely, untwisting accentuates if this interval is extended by positive inotropic drug intervention,59 or becomes impaired if this interval is shortened by either negative inotropic drug intervention59 or by several other factors described below. Extending torsion by prolonged shortening of the right-handed helical arm or descending segment will impair untwisting because this delay compromises the postejection isovolumic time frame when unwinding should start. Consequently, a unifying influence of mechanical events during this “hiatus time frame” evolves into a torsion/untwisting interdependence that plays a major role that results in diastolic dysfunction.

Diastolic Dysfunction The term diastolic dysfunction has been used because heart failure occurs in patients with normal ejection fraction, implying that the problem is diastolic in origin. However, Tan86 has done an extensive echocardiographic analysis and emphasized that it is not an isolated diastolic disorder; each patient displays combined systolic and

1202


Myocyte Factors

Fig. 55.21: The average relation between apical velocity rotation and timing for human left ventricle (LV) in controls, and physiological (rowers) and pathological hypertrophy (aortic stenosis). Data from magnetic resonance imaging (MRI) tagging show rapid changes in early and late systole and early diastole, demonstrating prolongation of late systolic velocity into the early diastolic phase in aortic stenosis. (ES: end-systole).

Myocyte causes relate to thickened LV mass due to increased afterload from aortic stenosis, hypertension, or hypertrophic cardiomyopathy.14,15 Stuber employed MRI to demonstrate that aortic stenosis causes increased peak torsion, longer interval to peak torsion,60 (Fig. 55.21) and impaired untwisting. Similar alterations happen after concentric hypertrophy in hypertension90 and hypertrophic cardiomyopathy. Treatment options should address the specific cause of hypertrophy, because alleviating the cause of LV hypertrophy allows regression of LV mass to return twisting and untwisting capacity toward normal by aortic valve replacement.91 Similar results likely follow pharmacological management to reduce the increased systemic vascular resistance, or alcohol or surgical removal of the hypertrophied ventricular segment.92

Calcium-Related Factors diastolic abnormalities, particularly involving ventricular twist and deformation (strain) patterns leading to reduced ventricular suction, delayed untwisting, and impaired early diastolic filling.87,88 These observations emphasize the interdependence of twisting and untwisting. Diastolic dysfunction has clear echocardiography characteristics relating to changes in the velocity waves during rapid filling and atrial contraction. The role of the reported increased untwisting during early diastolic dysfunction is uncertain because the E-wave is reduced and impaired filling occurs.16,89 Diastolic dysfunction’s characteristic impaired untwisting is associated with either (a) increased torsion and preserved ejection fraction or (b) reduced torsion from reduced systolic function. The underlying problem is prolonged shortening of the right-handed helical arm or descending segment that causes extended torsion duration with resultant compromise of the vital postejection isovolumic phase “timing hiatus”. The keynote echocardiographic observation is loss of longitudinal strain, a process caused by the prolonged descending segment contraction causing prolonged torsion, so that there is a delay in allowing the noncontracting descending segment to become a fulcrum for lengthening. Several reasons exist for this descending segment prolongation, and the resultant treatment options are determined by whether the causative factor relates to (a) regional muscle anatomy, (b) physiological calcium flux, or (c) geometric interruption of normal fiber orientation by cardiac dilation.

Sarcolemmal calcium flux efficiency is a central underlying event in both ischemia and aging.63,93 Kroeker studied94 twist dynamics during early ischemia and observed that counterclockwise apical rotation was prolonged into the isovolumic phase. A similar event occurs with aging,95 and is also associated with prolonged shortening of the descending segment after reperfusion following longer ischemic intervals.94 Although prior suggestions for defining the aging mechanism include left atrium considerations and LV pressure deceleration changes,95,96 neither has addressed the impaired subendocardial muscle function described by Lumens, that will prolong inner shell shortening.96 Management options for improving torsion and untwisting imbalance from these causes may relate to enhancing calcium flux by reperfusion after ischemia, or via pharmacological management with aging; the compromised “time hiatus” is improved by sodium hydrogen exchange inhibitors63 (Figs 55.22A to D). Moreover, favorably modifying calcium efficiency by levosimendan similarly reverses diastolic dysfunction.97

Dilated Cardiomyopathy Geometric reasons for diminished torsion and impaired untwisting become apparent as the normal conical ventricular shape becomes spherical in dilated cardiomyopathy, as increased sphericity index is a primary determinant of abnormal twisting and associated diastolic dysfunction.79 Geometric changes thereby become the


A

B

C

D

1203

Figs 55.22A to D: Sonomicrometer crystal tracings of “hiatus between termination of right- and left-handed helix or descending and ascending segment contraction” during the isovolumic phase in the normal heart. A yellow shade defines this interval, and there is recording of left ventricular pressure and dP/dt. (A) Normal or control intervals; (B) Bulging of both segments during ischemia or temporary coronary occlusion, without shortening; (C) 15 minutes after reperfusion shows reduced shortening, prolongation of right-handed helix, or descending segment contraction that markedly reduces the hiatus between termination of the right- and left-handed helices or descending and ascending shortening; (D) Diastolic dysfunction is percentage prolongation of “hiatus” between end of shortening of right-handed helix (descending segment) and left-handed helix or ascending segment. Prolonged right-handed helix or descending shortening defines this interval. The treated animals received cariporide, a sodium hydrogen ion inhibitor called HOE pretreatment. Control values are shown below. Values expressed as mean ± SEM. Note return of normal hiatus following this intervention (*P < 0.05 HOE pretreatment vs no treatment).

unifying theme of torsion and untwisting dysfunction in dilated cardiomyopathy from ischemic, valvular, and nonischemic origin.98 Sallin33 showed that ejection fraction diminishes as the oblique helical configuration develops a more horizontal fiber orientation, and dilation simultaneously stretches the fibers to also impair their electrophysiological function.99 Moreover, diminished untwisting is a hallmark sign of dilated cardiomyopathy, so that this event stems from prolonged torsion to thereby solidify the interdependence of the torsion and untwisting

relationship. Consequently, returning the helical form with a spectrum of restoration procedures may reverse the adverse torsion and untwisting interdependence in dilated hearts.82

Pacing Factors Cardiac motion studies show that normal cardiac movement is sequential due to spread of the electrical impulse from its earliest action within the conduction

1204


system toward its transition across the matrix and into the muscle fibers.100 Heart motion after a single transmural electrical excitation is synchronous, so that it is not surprising why Wiggers in 1925 demonstrated that ventricular pacing disturbed cardiac muscle movement adversely.101 Recent studies of torsion and untwisting during isolated ventricular pacing102,103 confirm how a single pacing stimulus interferes with these natural patterns. Biventricular pacing or cardiac resynchronization therapy (CRT) also causes an inconsistent torsion and untwisting improvement, because this fixed dual stimulus differs from the natural spread of impulses via the His Purkinje system that produces sequential motion. A recent study in CRT responders demonstrated the apex and base moving in the same direction or synchrony,52 instead of twisting, thereby demonstrating their production of transmural stimulation rather than sequential activation along the His Purkinje system. Sonomicrometer crystal studies document loss of the sequential motion following atrium and then biventricular stimulation.104 Conversely, there is restoration of the natural twisting and untwisting, as sequential motion returns following atrial and then high septal pacing;104 this pattern reflects the natural His bundle pacing. Torsion and untwisting thereby require a coordinated spread of impulses to the circular and helical pathways to ensure the natural excitation contraction coordination that does not interfere with the postejection isovolumetric interval “time hiatus”.

Right Heart Failure The septum is the “lion of RV function,”105 because the RV must rely upon the requisite twisting of its helical fibers to maintain RV cardiac output against increased PVR.105 In contrast, paradoxical septum motion follows its stunning during cardiac surgery70 or from its stretch following volume overloading. The consequent bulging septal geometric change causes its oblique fibers to become more transverse to decrease its twisting capacity; this infrastructure progresses to RV failure during pulmonary hypertension. In contrast, the power of the RV free wall’s compressive capacity is apparent when PVR is low; RV failure did not occur in approximately 50% of the 3,292 consecutive surgical patients who developed paradoxical septal motion following conventional methods of myocardial protection.70 Most importantly, the septum and LV free wall are made of the same helical muscle, so that LV diastolic dysfunction should occur whenever the septum is globally stunned.

A close relationship exists between the septum and tricuspid valve function, because its base anchors the part of the A to V valve annulus and RV septum papillary muscles arise from its body. Tricuspid valve regurgitation (TR) develops when ventricular dilation stretches the septum, a change that is caused by tethering of valve leaflets; this mirrors the reason for MR development occurring in patients with a wide QRS interval (Figs 55.23A and B). Moreover, studies from our laboratory show that acute pulmonary hypertension causes septum bowing and resultant TR, both of which become reversed by supplementing phenylephrine with intra-aortic balloon pumping. This treatment restores the midline RV septum position, while simultaneously avoiding LV vasoconstrictor drugs induced after loading.106 RV failure treatment protocols are linked to understanding the functional HVMB causes of performance impairment. Postoperative paradoxical septum motion is totally avoided by use of the integrated blood cardioplegia during open heart surgery.68 Abolition of postoperative arrhythmias and right heart failure was achieved by a “valve ventricular approach” that reconstructed the stretched septum and replaced the pulmonary valve in the dilated failing hearts.71 RV dysplasia was successfully treated by normalizing the size of the aneurysmal free wall,107 as the septum is not diseased in 80% of these patients.108 RV failure is reversed in left ventricular assist device (LVAD) patients by reducing LV suction to return the bowed septum to the midline position.109 Realization that septal twisting is further impaired by the high pulmonary pressures in RV failure patients has resulted in avoidance of vasoconstrictor drugs (epinephrine, dopamine), and selection of the amrinone or milrinone agents, which combine vasodilator and inotropic actions. The theme of these clinical implications is that unbalanced torsion and untwisting have a common premise related to the impaired “timing hiatus” or longer torsion duration during the postejection isovolumic phase. Decisions about management become linked to focusing upon how this common abnormality is altered within different muscular, physiological, structural, and electrical disease processes. Treatment options then become geared toward efforts to reverse the initiating event. Readily available torsion and untwisting monitors may be employed to gauge their effectiveness.

CONCLUSION Ventricular torsion is due to the twisting of the ventricle during systole, and its subsequent untwisting is the prelude


1205

A

B to subsequent diastolic filling. These interdependent rotational events arise from the mechanical actions and timing relationships of the heart’s underlying circular and helical muscle pathways. Explanation of the presystolic IVC period is essential for analysis of these interactions. Circular fibers dominate to cause pre- and post-twisting net or global counterclockwise and clockwise movement, whereas the helical fibers govern torsion. Normal

Figs 55.23A and B: (A) Left intraventricular view of the septum. Note that the posterior medial papillary muscle arises from the left ventricular (LV) wall immediately adjacent to the septum. Paradoxical or bowing septal motion causes it to bulge into the right ventricle, so that the adjacent posterior papillary motion moves in that direction, and results in tethering the mitral valve leaflets to cause mitral regurgitation from this geometric reason; (B) Right intraventricular appearance of the septum. Note attachments of the posterior papillary muscles to the septum wall as well as tricuspid valve leaflets. Observe that leftward bowing of septum will produce traction upon the septum cusp leaflets and alter coaptation and cause valve incompetence.

untwisting is related to preserving the 80-ms “timing hiatus” between the end of shortening of the descending and then the ascending arms of the helical muscle. Central to understanding torsion and untwisting interdependence is knowledge of the mechanics of normal cardiac motion during the timing of the coiling and recoiling actions of circular and helical fiber pathways. Longer torsion duration results from prolonged right-

1206


handed helical arm or descending segment contraction that compromises this “timing hiatus” and thereby interferes with untwisting. Clinical implications result from unbalanced torsion and untwisting, and longer torsion duration becomes their common theme. Management decisions relate to interconnected reasons for adverse mechanical and timing factors that cause this common abnormality within muscular, physiological, structural, and electrical disease processes.

REFERENCES 1. Keith A. Harveian lecture on the functional anatomy of the heart. Br Med J. 1918;1(2987):361–3. 2. Lower R. Tractus de Corde 1669. In: Gunther RT, editor. Early Science in Oxford. Oxford: Sawsons; 1932. 3. Senac JB. Traite De La Structure Du Coeur. Paris: Vincent; 1749. 4. Krehl L. Kenntniss der fallung und entleerung des herzens. Abhandl Math Phys. 1891; 29:341–62. 5. Robb JS, Robb RC. The normal heart: anatomy and physiology of the structural units. Am Heart J. 1942;23:455– 67. 6. Grant RP. Notes on the muscular architecture of the left ventricle. Circulation. 1965;32:301–8. 7. Lev M, Simkins CS. Architecture of the human ventricular myocardium, technique for study using a modification of the Mall-MacCallum method. Lab Invest. 1956; 8:306–409. 8. Anderson RH, Ho SY, Sanchez-Quintana D, Redmann K, Lunkenheimer PP. Heuristic problems in defining the threedimensional arrangement of the ventricular myocytes. Anat Rec A Discov Mol Cell Evol Biol. 2006;288(6):579–86. 9. Torrent-Guasp F. An Experimental Approach on Heart Dynamics. Madrid:S. Aguirre Torre; 1959. 10. Torrent-Guasp F, Ballester M, Buckberg GD, et al. Spatial orientation of the ventricular muscle band: physiologic contribution and surgical implications. J Thorac Cardiovasc Surg. 2001;122(2):389–92. 11. Torrent-Guasp F, Buckberg GD, Clemente C, et al. The structure and function of the helical heart and its buttress wrapping. I. The normal macroscopic structure of the heart. Semin Thorac Cardiovasc Surg. 2001;13(4):301–19. 12. Thomas JD, Popovic ZB. Assessment of left ventricular function by cardiac ultrasound. J Am Coll Cardiol. 2006; 48(10):2012–25. 13. Sengupta PP, Korinek J, Belohlavek M, et al. Left ventricular structure and function: basic science for cardiac imaging. J Am Coll Cardiol. 2006;48(10):1988–2001. 14. Bertini M, Sengupta PP, Nucifora G, et al. Role of left ventricular twist mechanics in the assessment of cardiac dyssynchrony in heart failure. JACC Cardiovasc Imaging. 2009;2(12):1425–35. 15. Sengupta PP, Tajik AJ, Chandrasekaran K, et al. Twist mechanics of the left ventricle: principles and application. JACC Cardiovasc Imaging. 2008;1(3):366–76.

16. Buckberg G, Hoffman JI, Mahajan A, et al. Cardiac mechanics revisited: the relationship of cardiac architecture to ventricular function. Circulation. 2008; 118(24):2571–87. 17. Buckberg G, Hoffman JI, Nanda NC, et al. Ventricular torsion and untwisting: further insights into mechanics and timing interdependence: a viewpoint. Echocardiography. 2011;28(7):782–804. 18. Buckberg GD, Mahajan A, Saleh S, et al. Structure function relationships of the Helical Ventricular Myocardial Band. J Thoracic Cardiovasc Surg. 2007; In Press. 19. Mall FP. On the muscular architecture of the ventricles of the human heart. Am J Anat. 1911;11:211–78. 20. Streeter DD, Powers WE, Ross MA, et al. Three-dimensional fiber orientation in the mammalian left ventricular wall. In: Baan, Noordergraaf, Raines, editors. Cardiovascular System Dynamics. Cambridge: MIT Press; 1978:73. 21. Geerts L, Bovendeerd P, Nicolay K, et al. Characterization of the normal cardiac myofiber field in goat measured with MR-diffusion tensor imaging. Am J Physiol Heart Circ Physiol. 2002;283(1):H139–45. 22. Chen J, Song SK, Liu W, et al. Remodeling of cardiac fiber structure after infarction in rats quantified with diffusion tensor MRI. Am J Physiol Heart Circ Physiol. 2003; 285(3):H946–54. 23. Jiang Y, Pandya K, Smithies O, et al. Three-dimensional diffusion tensor microscopy of fixed mouse hearts. Magn Reson Med. 2004;52(3):453–60. 24. Wu MT, Tseng WY, Su MY, et al. Diffusion tensor magnetic resonance imaging mapping the fiber architecture remodeling in human myocardium after infarction: correlation with viability and wall motion. Circulation. 2006;114(10):1036–45. 25. Sosnovik DE, Wang R, Dai G, et al. Diffusion MR tractography of the heart. J Cardiovasc Magn Reson. 2009;11:47. 26. Zhukov L, Barr AH. Heart-muscle fiber reconstruction from diffusion tensor MRI. In Proceedings of IEEE Visualization 2003, IEEE Computer Society Press. 2003:597–602. 27. Lunkenheimer PP, Müller RP, Konermann C, et al. Architecture of the myocardium in computed tomography. Invest Radiol. 1984;19(4):273–8. 28. Streeter DD, Torrent-Guasp F. Geodesic paths in the left ventricle of the mammalian heart. Circulation. 1973; XLVIII(4). 29. Buckberg G, Mahajan A, Saleh S, et al. Structure and function relationships of the helical ventricular myocardial band. J Thorac Cardiovasc Surg. 2008;136(3):578–89,589.e1. 30. Streeter DD. The Cardiovascular System I. In: American Physiological Society, editor. Handbook of Physiology. Baltimore: Williams and Wilkins, 1979:61–112. 31. Clemente C. Anatomy: a regional atlas of the human Body. 5th ed. Lippincott, Williams and Wilkins; 2006. 32. Moore KL, Dalley AF. Clinically Oriented Anatomy. 5 ed. Lippincott & Wilkins, 2005. 33. Sallin EA. Fiber orientation and ejection fraction in the human left ventricle. Biophys J. 1969;9(7):954–64. 34. Caulfield JB, Janicki JS. Structure and function of myocardial fibrillar collagen. Technol Health Care. 1997;5(1–2):95–113.


35. Caulfield JB, Bittner V. Cardiac matrix alterations induced by adriamycin. Am J Pathol. 1988;133(2):298–305. 36. Sengupta PP, Khandheria BK, Korinek J, et al. Apex-to-base dispersion in regional timing of left ventricular shortening and lengthening. J Am Coll Cardiol. 2006;47(1):163–72. 37. Anderson RH, Sanchez-Quintana D, Redmann K, et al. How are the myocytes aggregated so as to make up the ventricular mass? Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2007:76–86. 38. Utley JR, Michalsky GB, Mobin-Uddin K, et al. Subendocardial vascular distortion at small ventricular volumes. J Surg Res. 1974;17(2):114–24. 39. Lunkenheimer PP, Redmann K, Westermann P, et al. The myocardium and its fibrous matrix working in concert as a spatially netted mesh: a critical review of the purported tertiary structure of the ventricular mass. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S41–9. 40. Taber LA , Yang M, Podszus WW. Mechanics of ventricular torsion. J Biomech. 1996;29(6):745–52. 41. Ingels NB Jr. Myocardial fiber architecture and left ventricular function. Technol Health Care. 1997;5(1–2): 45–52. 42. Sengupta PP, Krishnamoorthy VK, Korinek J, et al. Left ventricular form and function revisited: applied translational science to cardiovascular ultrasound imaging. J Am Soc Echocardiogr. 2007;20(5):539–51. 43. Bertini M, Marsan NA, Delgado V, et al. Effects of cardiac resynchronization therapy on left ventricular twist. J Am Coll Cardiol. 2009;54(14):1317–25. 44. Jung BA, Kreher BW, Markl M, et al. Visualization of tissue velocity data from cardiac wall motion measurements with myocardial fiber tracking: principles and implications for cardiac fiber structures. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S158–64. 45. Lorenz CH, Pastorek JS, Bundy JM. Delineation of normal human left ventricular twist throughout systole by tagged cine magnetic resonance imaging. J Cardiovasc Magn Reson. 2000;2(2):97–108. 46. Buckberg GD, Mahajan A, Jung B, et al. MRI myocardial motion and fiber tracking: a confirmation of knowledge from different imaging modalities. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S165–77. 47. Notomi Y, Setser RM, Shiota T, et al. Assessment of left ventricular torsional deformation by Doppler tissue imaging: validation study with tagged magnetic resonance imaging. Circulation. 2005;111(9):1141–7. 48. Notomi Y, Martin-Miklovic MG, Oryszak SJ, et al. Enhanced ventricular untwisting during exercise: a mechanistic manifestation of elastic recoil described by Doppler tissue imaging. Circulation. 2006;113(21):2524–33. 49. Castella M, Buckberg GD, Saleh S, et al. Structure function interface with sequential shortening of basal and apical components of the myocardial band. Eur J Cardiothorac Surg. 2005;27(6):980–7. 50. Buckberg GD, Castellá M, Gharib M, et al. Structure/ function interface with sequential shortening of basal and apical components of the myocardial band. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S75–97.

1207

51. Ashikaga H, van der Spoel TI, Coppola BA, et al. Transmural myocardial mechanics during isovolumic contraction. JACC Cardiovasc Imaging. 2009;2(2):202–11. 52. Rüssel IK, Götte MJ, de Roest GJ, et al. Loss of opposite left ventricular basal and apical rotation predicts acute response to cardiac resynchronization therapy and is associated with long-term reversed remodeling. J Card Fail. 2009;15(8):717–25. 53. Bogaert J, Rademakers FE. Regional nonuniformity of normal adult human left ventricle. Am J Physiol Heart Circ Physiol. 2001;280(2):H610–20. 54. Streeter DD Jr. Gross morphology and fiber geometry of the heart. In: Berne RM, editor. Handbook of Physiology. Baltimore: Williams and Wilkins; 1979:61–112. 55. Karlsson MO, Glasson JR, Bolger AF, et al. Mitral valve opening in the ovine heart. Am J Physiol. 1998;274(2 Pt 2):H552–63. 56. Helmes M, Trombitás K, Granzier H. Titin develops restoring force in rat cardiac myocytes. Circ Res. 1996;79(3):619–26. 57. Karwatowski SP, Brecker SJ, Yang GZ, et al. A comparison of left ventricular myocardial velocity in diastole measured by magnetic resonance and left ventricular filling measured by Doppler echocardiography. Eur Heart J. 1996;17(5): 795–802. 58. Lee CH, Vancheri F, Josen MS, et al. Discrepancies in the measurement of isovolumic relaxation time: a study comparing M mode and Doppler echocardiography. Br Heart J. 1990;64(3):214–18. 59. Notomi Y, Popovic ZB, Yamada H, et al. Ventricular untwisting: a temporal link between left ventricular relaxation and suction. Am J Physiol Heart Circ Physiol. 2008;294(1):H505–13. 60. Stuber M, Scheidegger MB, Fischer SE, et al. Alterations in the local myocardial motion pattern in patients suffering from pressure overload due to aortic stenosis. Circulation. 1999;100(4):361–8. 61. Yun KL, Niczyporuk MA, Daughters GT 2nd, et al. Alterations in left ventricular diastolic twist mechanics during acute human cardiac allograft rejection. Circulation. 1991; 83(3):962–73. 62. Tibayan FA, Lai DT, Timek TA, et al. Alterations in left ventricular torsion in tachycardia-induced dilated cardiomyopathy. J Thorac Cardiovasc Surg. 2002;124(1):43–9. 63. Castellá M, Buckberg GD, Saleh S. Diastolic dysfunction in stunned myocardium: a state of abnormal excitationcontraction coupling that is limited by Na+-H+ exchange inhibition. Eur J Cardiothorac Surg. 2006;29(Suppl 1): S107–14. 64. Dong SJ, Hees PS, Siu CO, et al. MRI assessment of LV relaxation by untwisting rate: a new isovolumic phase measure of tau. Am J Physiol Heart Circ Physiol. 2001; 281(5):H2002–9. 65. Notomi Y, Srinath G, Shiota T, et al. Maturational and adaptive modulation of left ventricular torsional biomechanics: Doppler tissue imaging observation from infancy to adulthood. Circulation. 2006;113(21):2534–41.

1208


66. Rademakers FE, Buchalter MB, Rogers WJ, et al. Dissociation between left ventricular untwisting and filling. Accentuation by catecholamines. Circulation. 1992;85(4):1572–81. 67. Shapiro EP, Rademakers FE. Importance of oblique fiber orientation for left ventricular wall deformation. Technol Health Care. 1997;5(1-2):21–8. 68. Buckberg G, Athanasuleas C, Saleh S. Septal myocardial protection during cardiac surgery for prevention of right ventricular dysfunction. Anadolu Kardiyol Derg. 2008; 8(Suppl 2):108–16. 69. Armour JA, Randall WC. Electrical and mechanical activity of papillary muscle. Am J Physiol. 1970;218(6):1710–17. 70. Reynolds HR, Tunick PA, Grossi EA, et al. Paradoxical septal motion after cardiac surgery: a review of 3,292 cases. Clin Cardiol. 2007;30(12):621–3. 71. Frigiola A, Giamberti A, Chessa M, et al.; RESTORE group. Right ventricular restoration during pulmonary valve implantation in adults with congenital heart disease. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S279–85. 72. Greenbaum RA, Ho SY, Gibson DG, et al. Left ventricular fibre architecture in man. Br Heart J. 1981;45(3):248–63. 73. Sakuma M, Ishigaki H, Komaki K, et al. Right ventricular ejection function assessed by cineangiography–Importance of bellows action. Circ J. 2002;66(6):605–9. 74. Wiggers C. Some factors controlling the shape of the pressure curve in the right ventricle. Am J Physiol. 1914;33: 382–95. 75. Starr I, Jeffers WA, Meade RH Jr. The absence of conspicuous increments of venous pressure after severe damage to the right ventricle of the dog, with a discussion of the relation between clinical congestive failure and heart disease. Am Heart J. 1943;26:291–301. 76. Sawatani S, Mandell G, Kusaba E, et al. Ventricular performance following ablation and prosthetic replacement of right ventricular myocardium. Trans Am Soc Artif Intern Organs. 1974;20 B:629–36. 77. Cox JL, Bardy GH, Damiano RJ Jr, et al. Right ventricular isolation procedures for nonischemic ventricular tachycardia. J Thorac Cardiovasc Surg. 1985;90(2):212–24. 78. Donald DE, Essex HE. Pressure studies after inactivation of the major portion of the canine right ventricle. Am J Physiol. 1954;176(1):155–61. 79. van Dalen BM, Kauer F, Vletter WB, et al. Influence of cardiac shape on left ventricular twist. J Appl Physiol. 2010; 108(1):146–51. 80. Buckberg G. Rethinking the cardiac helix: a structure/ function journey. Eur J Cardiothorac Surg. 2006;29S1:S1. 81. Buckberg GD. The structure and function of the healthy helical and failing spherical heart. Overview: the ventricular band and its surgical implications. Semin Thorac Cardiovasc Surg. 2001;13(4):298–300. 82. Buckberg GD; RESTORE Group. Form versus disease: optimizing geometry during ventricular restoration. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S238–44. 83. Buckberg GD, Coghlan HC, Torrent-Guasp F. The structure and function of the helical heart and its buttress wrapping. VI. Geometric concepts of heart failure and use

84.

85.

86.

87.

88.

89.

90.

91.

92.

93.

94.

95.

96.

97.

for structural correction. Semin Thorac Cardiovasc Surg. 2001; 13(4):386–401. Borg AN, Harrison JL, Argyle RA, et al. Left ventricular torsion in primary chronic mitral regurgitation. Heart. 2008;94(5):597–603. Nishimura RA, Tajik AJ. Evaluation of diastolic filling of left ventricle in health and disease: Doppler echocardiography is the clinician’s Rosetta Stone. J Am Coll Cardiol. 1997;30(1):8–18. Tan YT, Wenzelburger FW, Sanderson JE, et al. Exerciseinduced torsional dyssynchrony relates to impaired functional capacity in patients with heart failure and normal ejection fraction. Heart. 2013;99(4):259–66. Tan YT, Wenzelburger F, Lee E, et al. The pathophysiology of heart failure with normal ejection fraction: exercise echocardiography reveals complex abnormalities of both systolic and diastolic ventricular function involving torsion, untwist, and longitudinal motion. J Am Coll Cardiol. 2009;54(1):36–46. Pacileo G, Baldini L, Limongelli G, et al. Prolonged left ventricular twist in cardiomyopathies: a potential link between systolic and diastolic dysfunction. Eur J Echocardiogr. 2011;12(11):841–9. Park SJ, Miyazaki C, Bruce CJ, et al. Left ventricular torsion by two-dimensional speckle tracking echocardiography in patients with diastolic dysfunction and normal ejection fraction. J Am Soc Echocardiogr. 2008;21(10):1129–37. Mizuguchi Y, Oishi Y, Miyoshi H, et al. Concentric left ventricular hypertrophy brings deterioration of systolic longitudinal, circumferential, and radial myocardial deformation in hypertensive patients with preserved left ventricular pump function. J Cardiol. 2010;55(1):23–33. Van Der Toorn A, Barenbrug P, Snoep G, et al. Transmural gradients of cardiac myofiber shortening in aortic valve stenosis patients using MRI tagging. Am J Physiol Heart Circ Physiol. 2002;283(4):H1609–15. Carasso S, Woo A, Yang H, et al. Myocardial mechanics explains the time course of benefit for septal ethanol ablation for hypertrophic cardiomyopathy. J Am Soc Echocardiogr. 2008;21(5):493–9. Kho C, Lee A, Hajjar RJ. Altered sarcoplasmic reticulum calcium cycling–targets for heart failure therapy. Nat Rev Cardiol. 2012;9(12):717–33. Kroeker CA, Tyberg JV, Beyar R. Effects of ischemia on left ventricular apex rotation. An experimental study in anesthetized dogs. Circulation. 1995;92(12):3539–48. Hees PS, Fleg JL, Dong SJ, et al. MRI and echocardiographic assessment of the diastolic dysfunction of normal aging: altered LV pressure decline or load? Am J Physiol Heart Circ Physiol. 2004;286(2):H782–8. Lumens J, Delhaas T, Arts T, et al. Impaired subendocardial contractile myofiber function in asymptomatic aged humans, as detected using MRI. Am J Physiol Heart Circ Physiol. 2006;291(4):H1573–9. Barraud D, Faivre V, Damy T, et al. Levosimendan restores both systolic and diastolic cardiac performance in lipopolysaccharide-treated rabbits: comparison with


98.

99.

100.

101.

102.

103.

dobutamine and milrinone. Crit Care Med. 2007;35(5): 1376–82. Buckberg GD. Rethinking the cardiac helix–a structure/ function journey: overview. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S2–3. St John Sutton M, Lee D, Rouleau JL, et al. Left ventricular remodeling and ventricular arrhythmias after myocardial infarction. Circulation. 2003;107(20):2577–82. Coghlan HC, Coghlan AR, Buckberg GD, et al. The structure and function of the helical heart and its buttress wrapping. III. The electric spiral of the heart: The hypothesis of the anisotropic conducting matrix. Semin Thorac Cardiovasc Surg. 2001;13(4):333–41. Wiggers CJ. The muscular reactions of the mammalian ventricles to artificial surface stimuli. Am J Physiol. 1925;(73):346–78. Sorger JM, Wyman BT, Faris OP, et al. Torsion of the left ventricle during pacing with MRI tagging. J Cardiovasc Magn Reson. 2003;5(4):521–30. Wang J, Nagueh SF, Mathuria NS, et al. Left ventricular twist mechanics in a canine model of reversible congestive heart failure: a pilot study. J Am Soc Echocardiogr. 2009;22(1): 95–8.

1209

104. Tomioka H, Liakopoulos O, Buckberg GD, et al. The effect of ventricular sequential contraction on helical heart during pacing. Europ J Cardiothorac Surg. 2006. 105. Saleh S, Liakopoulos OJ, Buckberg GD. The septal motor of biventricular function. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S126–38. 106. Liakopoulos OJ, Ho JK, Yezbick AB, et al. Right ventricular failure resulting from pressure overload: role of intra-aortic balloon counterpulsation and vasopressor therapy. J Surg Res. 2010;164(1):58–66. 107. Buckberg GD, Coghlan HC, Hoffman JI, Torrent-Guasp F. The structure and function of the helical heart and its buttress wrapping. VII. Critical importance of septum for right ventricular function. Semin Thorac Cardiovasc Surg. 2001;13(4):402–16. 108. Basso C, Thiene G, Corrado D, et al. Arrhythmogenic right ventricular cardiomyopathy. Dysplasia, dystrophy, or myocarditis? Circulation. 1996;94(5):983–91. 109. Neragi-Miandoab S, Goldstein D, Bello R, et al. Right ventricular dysfunction following continuous flow left ventricular assist device placement in 51 patients: predicators and outcomes. J Cardiothorac Surg. 2012;7:60.

CHAPTER 56 Echocardiography in Assessment of Complications Related to Permanent Pacemakers and Intracardiac Defibrillators Ahmed Almomani, Khadija Siddiqui, Masood Ahmad

Snapshot ¾¾ Normal Echocardiographic Findings in Permanent

Pacemakers/Implantable Cardioverter-Defibrillators ¾¾ Pacemaker and Implantable Cardioverter-DefibrillatorRelated Complications ¾¾ Tricuspid Regurgitation

INTRODUCTION Over the past decades, technical advances in permanent pacemakers (PPMs) and implantable cardioverter-defibri llators (ICDs) have led to a tremendous increase in the use of these medically important devices. This trend is likely to continue due to the increased life expectancy of the population and the increasing number of indications for their use including placement of PPMs for cardiac resynchronization therapy (CRT) and ICDs for primary and secondary prevention of complications from arrhythmias in patients with left ventricular dysfunction.1–3 The 11th World Survey of Cardiac Pacing and ICDs reported that 737,840 new devices were implanted in 2009 worldwide, with the largest number of new implants, 225,567, in the United States. These numbers showed a huge increase compared to a similar survey done in 2005, and the numbers are expected to be much higher in 2013.4

¾¾ Masses: Lead Infection and Thrombus ¾¾ Myocardial Perforation ¾¾ Deleterious Effects of Right Ventricular Apical Pacing on

Left Ventricular Function

Endocardial lead-related complications have not been very well recognized. In recent years, there has been an increasing awareness of device-related complications such as tricuspid regurgitation (TR), lead infection, thrombosis, perforation, and left ventricular dyssynchrony. We will review the roles of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in the assessment of pacemaker/ICD endocardial lead-related complications.

NORMAL ECHOCARDIOGRAPHIC FINDINGS IN PERMANENT PACEMAKERS/IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS Transthoracic echocardiography can be used to visualize the intracardiac portion of the PPM or ICD lead. Device

Chapter 56: Echo in Assessment of Complications Related to Permanent Pacemakers and Intracardiac Defibrillators

1211

A

B

C

D

E

Figs 56.1A to E: Two-dimensional transthoracic echocardiography (2D TTE) with pacer lead shown in modified parasternal long-axis (A), short-axis (B), apical four-chamber (C), focused right-sided chambers (D), and subcostal (E) views. Arrowheads point to the lead, arrow in Figure A points to the tricuspid valve. (AO: Aortic valve; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

leads may be imaged in the right atrium or right ventricle (RV) in a number of views, including RV inflow, parasternal short-axis at the level of the aortic valve, apical fourchamber, or subcostal view (Figs 56.1A to E). However, in some patients, the presence of lead cannot be satisfactorily

demonstrated due to poor acoustic windows resulting in limited visualization, and due to artifacts related to lead reverberations. Real time transthoracic threedimensional echocardiography (RT3DE) can overcome some of these limitations by visualizing the entire route

1212


A

B

C

D

Figs 56.2A to D: Real time transthoracic three-dimensional echocardiography (RT3DE) in apical four-chamber view demonstrating the pacer route and its relation to intracardiac structures in simultaneously obtained multiple views derived from the same data set. Arrowheads point to the lead. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: right ventricle).

of the lead in multiple views from the same data set (Figs 56.2A to D, and Movie clips 56.1 and 56.2). In addition, in some patients with RV pacing, there may be paradoxical septal motion due to early activation of the RV. This, however, is not a finding isolated to the presence of cardiac devices but can also be seen in the presence of other conduction abnormalities, cardiac surgery, or RV volume/pressure overload.

PACEMAKER AND IMPLANTABLE CARDIOVERTER-DEFIBRILLATORRELATED COMPLICATIONS Transthoracic echocardiogrphy and Transesophageal echocardiography are useful in evaluating pacemakerrelated complications including TR, valvular or lead vegetations, pericardial effusion, abnormal lead position, perforation, and lead thrombus.

TRICUSPID REGURGITATION The development of significant TR and its progression over time is an important device-related complication. Prospective data on TR secondary to PPM and ICD leads are lacking. Multiple small retrospective studies and small case series have reported this complication (Table 56.1). TR in patients with PPMs or ICDs may not be exclusively caused by the endocardial lead, as preexisting abnormalities such as tricuspid valve (TV) annular dilatation or pulmonary hypertension may be present.5 A number of different mechanisms of RV intracardiac lead-related TR have been described. In one retrospective study, it was noted that in 41 patients with PPM or ICD lead-induced severe TR requiring surgery, 7 patients had perforation of the TV leaflet by the PPM or ICD lead, 4 had lead entanglement in the TV, 16 had lead impingement of the TV leaflets, and 14 had lead adherence to the TV.6


1213

Table 56.1: Summary of the Studies on Pacemaker-Related Tricuspid Regurgitation

Study Sakai et al. (1987)58 Paniagua et al. (1998)

59

TR Before Lead TR After TR Severity Implantation Implantation

Sample Size

Study Design

Follow-up

18

Prospective

NA

NA

5

TR severity not assessed

374 cases

Case control

NA

NA

27

Moderate to severe TR

NA

NA

12

(P < 0.0001)

1.2 ± 0.7 days

10

7

Moderate to severe TR (P = Not significant)

NA

NA

Out of 1,465 patients with severe TR that required surgery, 41 were secondary to endocardial leads

9

12

Moderate to severe TR (P = Not significant)

683 controls Leibowitz et al. (2000)

35

Prospective

Lin et al. (2005)6

41

Retrospective

Kucukarslan et al. (2006)61

61

Prospective

Seo et al. (2008)7

87

Retrospective 36 months

NA

32

Moderate to severe TR3D echocardiography was used

Kim et al. (2008)62

248

Retrospective 93 days (range, 23–199)

69

NA

TTE before and after pacer showed significant increases in TR, moderate to severe in 24.2% and severe in 4%

Klutstein et al. (2009)63

410

Retrospective 75 days (range, 1–4,367 d)

NA

NA

TTE before and after pacer showed that 75 patients (18.3%) had significant worsening of TR

Vaturi et al. (2010)64

23

Prospective

48.6 ± 32.7 months

0

9

Moderate to severe TR. Number increased to 18 when mode changed to active RV pacing (P < 0.001)

Alizadeh et al. (2011)65

115

Prospective

4.1 ± 0.8 years

10

36

Moderate to severe TR (P < 0.001)

60

6 ± 3 months

(RV: Right ventricle; TR: Tricuspid regurgitation; TTE: Transthoracic echocardiography). Source: Modified with permission from Al-Mohaissen MA, Chan KL. Prevalence and mechanism of tricuspid regurgitation following implantation of endocardial leads for pacemaker or cardioverter-defibrillator. J Am Soc Echocardiogr. 2012;25(3):245–52.

In the same study, severe lead-induced TR causing rightheart failure that required TV surgery accounted for 2.8% of all TV operations (41 of 1,465 consecutive patients) between 1993 and 2003 at the Mayo Clinic. The time course for TR development and progression after endocardial lead placement in the RV is not well defined. A large retrospective study reported an increase in TR acutely after RV lead implantation, and progressive worsening with time, while other studies have mainly focused on the chronic effects of the leads on the valve.7 Pathological studies have demonstrated major inflammatory changes occurring within the heart only days after lead implantation. The progression of inflammation

over weeks to months leads to fibrous tissue formation, which encapsulates the pacemaker lead and may result in fusion and adherence of the endocardial lead to the TV leaflets, chordae, and papillary muscles, resulting in TR.8 Transthoracic echocardiography is often used to assess TR after implantation of PPMs (Fig. 56.3 and Movie clip 56.3). However, the ability to define the precise anatomical relationship between the TV and the pacemaker lead is quite limited using this modality. In a study done at Mayo Clinic, the valve malfunction due to PPM or ICD lead was diagnosed preoperatively in only 5 of 41 patients by TTE.6 On the other hand, RT3DE enables visualization of the entire TV, in

1214


Fig. 56.3: Two-dimensional transthoracic echocardiography (2D TTE) with focused view of right-sided chambers, demonstrating the tricuspid regurgitation (TR) jet (arrow) between the right ventricle (RV) lead (arrow head) and the septal leaflet of the tricuspid valve (TV).

particular, en-face short-axis views of the valve, which may facilitate the enhanced ability of this technique in assessing the route and position of the lead at the TV and in visualizing the actual movement of the leaflets (Figs 56.4A and B, and Movie clips 56.4 and 56.5). A high efficacy (96%) of 3DE in complete assessment of the TV structure has also been reported.9 Another study reported that among the 87 patients involved in the study, leads passing through the TV were identified in only 15 (17.2%) patients by 2D. In contrast, on 3DE examinations, lead routes were identified in 82 (94.2%) patients. In the remaining five patients, appropriate 3DE images for lead route analysis could not be obtained because of artifacts caused by the lead.7 Tricuspid regurgitation is a preventable complication of PPM and ICD leads, and is related to the lead position, lead route, and interaction with the valve leaflets. Prospective studies are needed to establish the temporal relationship between placement of the device and development/severity of TR. Real time 3D echocardiography appears superior to two-dimensional transthoracic echocardiography (2D TTE) in assessing the TV in patients with PPMs and ICDs (Figs 56.4A and B).

MASSES: LEAD INFECTION AND THROMBUS As there has been an increase in the number of implanted cardiac devices over the past couple of decades, there has

also been a notable increase in the detection of masses on these leads. Of the available imaging modalities, magnetic resonance imaging still continues to be relati vely contraindicated in a majority of pacemakers and defibrillators, therefore limiting evaluation of these devices by either computed tomography (CT) or echocardiography. However, since the metal in the device and the movement of the leads create artifacts on CT, the most desirable imaging modality remains an echocardiogram. A mass detected on an implanted lead on an echocardiogram, almost invariably represents either a thrombus or vege tation, and distinguishing between the two can often be quite difficult. Since ultrasound imaging alone cannot determine the etiology of the mass, clinical presentation and lab data play a crucial role in the interpretation and management of these abnormal findings.

Infection Initial cases of pacemaker endocarditis were described in the early 1970s.10 Reported device-related infective endocarditis (IE) has ranged from 10% to 23% in the literature.11,12 The incidence of infection following implan tation of PPMs has been variably assessed, ranging from 0.13% to 19.9%,13,14 with the majority of infections repo rted to be in the pacemaker generator pocket. Incidence of infection in ICDs has been reported in the literature ranging from 0.7% to 1.2%.15,16 Technical advances have allowed transvenous implantation of ICDs, thereby eliminating the need for thoracotomy and epicardial lead placement. These advances have contributed to the overall decline in infection associated with ICD. In patients with device-related endocarditis, the presence of vegetation is limited not only to the TV but can be found anywhere along the course of the lead, including the endocardium of the right atrium or RV.17 Echocardiography plays an important role by allowing direct visualization and measurement of the mass along with the ability to assess for cardiac involvement. On echocardiography, vegetations have been defined as oscillating intracardiac masses on the device leads, valve leaflets, or endocardial surface, confirmed by imaging in more than one echocardiographic plane. In these cases, the valve or lead infection was confirmed by positive blood or lead tip culture.12,18 Valvular vegetations have been further characterized on the basis of four physical properties, as assessed by echocardiography: vegetation size, mobility, extent, and consistency.18


A

1215

B

Figs 56.4A and B: Real time transthoracic three-dimensional echocardiography (RT3DE) with pacer and en-face view of the tricuspid valve from the right atrium (A). Pacer and the tricuspid valve from the right ventricle (B), the lead position (arrowhead) in relationship to the tricuspid valve (arrow).

Although TTE has an improved sensitivity later in the course of the disease, even then the overall sensitivity is quite poor.19 This is in part due to the difficulty in precisely distinguishing between abnormal masses, the TV, and the lead itself—mainly as a result of limited visualization, poor echogenicity in some patients, and artifacts due to lead reverberations in others. In contrast, use of a multiplane echocardiographic probe with TEE improves the quality of exploration and has a much more established role as a diagnostic technique. The ability to visualize the entire intracardiac route of the leads, from the upper vena cava to the RV apex, provides TEE with its much higher sensitivity and specificity. In three of the larger studies that used strict criteria for entry and compared results with surgical and microbiological endpoints, the sensitivity of TTE was 22–30%, while that of TEE was 92–96%.19–21 In addition, TEE also has a role in defining the most appropriate extraction technique by identifying patients with myocardial abscess or extremely large (> 5 cm) lead vegetations that may necessitate surgery rather than a percutaneous method of extraction.12

Thrombus Venous thrombosis and stenosis have been described as the most common complications associated with transvenous pacemaker implantation with incidence ranging between 30% and 45%.22 Right atrial thrombus is a rarely reported event, and can present either as an incidental finding on echocardiogram,23 or as symptoms of right-sided heart failure,24 obstruction, or embolization of the pulmonary artery.25 One study described only two

cases of large right atrial thrombi that were found in a series of 53 necropsies performed in patients with PPM. Both patients had evidence of hemodynamic impairment with signs of congestive heart failure. This series suggested that a right atrial thrombus should be considered in the setting of refractory heart failure, despite a normally functioning pacemaker and adequate medical treatment. Other serious complications such as superior vena cava syndrome have also been reported but are beyond the scope of this review.26 As stated, the diagnosis on TTE may be technically challenging in patients with limited acoustic windows and lead reverberations. On the other hand, TEE allows direct visualization of the lead, the entire right atrium, interatrial septum, superior vena cava, and inferior vena cava (Fig. 56.5 and Movie clip 56.6). TEE has also been sugg ested to provide information that can possibly determine whether the thrombus is recent or long-standing.27 Longstanding thrombi tend to be sessile and sometimes contain calcium. In contrast, fresh thrombi are highly mobile and appear less echo-dense. The use of 3D with TTE or TEE has an incremental value in evaluating masses attached to the leads (Fig. 56.6 and Movie clip 56.7). As discussed above, differences in clinical presentation and laboratory findings play a significant role in distinguishing lead infection from thrombus.

MYOCARDIAL PERFORATION Myocardial perforation is a relatively rare complication of endocardial leads of cardiac implantable devices. The incidence of this complication is estimated to be < 1%.

1216


Fig. 56.5: Two-dimensional transesophageal echocardiography (2D TEE) showing the pacer lead (arrowhead) and attached mobile thrombus (arrow).

Fig. 56.7: Echocardiography (four-chamber apical view): implantable cardioverter-defibrillator (ICD) lead perforation across the right ventricular apex. (LV: Left ventricle; PE: Pericardial effusion; RV: Right ventricle). Source: Reproduced with permission from Sassone B, Gabrieli L, Boggian G, Pilato E. Management of traumatic implantable cardioverter defibrillator lead perforation of the right ventricle after car accident: a case report. Europace. 2009;11(7):961–2.

In some studies the lead perforation rates range from 0.1% to 0.8% for PPMs and 0.6% to 5.2% for ICD leads. Lead perforation rates may depend on the lead model.28 Furthermore, lead perforation can be categorized into two groups: acute perforation after lead placement, which is mostly related to the procedure, and subacute or delayed

Fig. 56.6: Real time transthoracic three-dimensional echocardiography (RT3DE) of the pacer lead shown in Figure 56.5; right ventricle (RV) lead (arrowhead) with a thrombus (arrow).

perforation defined as the perforation of the lead through the myocardium more than 1 month after implantation.28–35 In a review of 51 reported cases of delayed lead perforation, the demographics and characteristics of this group showed that elderly women and patients with lower body mass are more vulnerable to this complication.36 Table 56.2 summarizes 35 cases reported in the literature. Unlike acute lead perforation, one of the distinguishing features of delayed lead perforation is the low risk of cardiac tamponade and death.37–39 Lead perforation can sometimes be identified by chest X-ray showing the lead’s migration outside the heart.36,40 Chest CT plays a crucial role in the diagnosis of lead perforation when other modalities are nondiagnostic.40,41 In one report, 15 out of 100 asymptomatic patients with pacemakers or ICDs were found to have late lead perforation on chest CTs performed for other reasons.40 However, CT images may be limited by artifacts created by the leads. Two-dimensional echocardiography is a valuable tool for the diagnosis of lead perforation and dislodgement (Fig. 56.7).42 This modality can also demonstrate pericardial effusion and tamponade if present. Difficulty or failure of 2D TTE to visualize leads is not uncommon. Transthoracic RT3DE is superior to 2D TTE in detecting lead perforation and its route (Fig. 56.8). RT3DE is complementary to 2D TTE in clinical practice and should be used if a lead complication is suspected.43,44


1217

Table 56.2: Summary of the Reported Cases of Lead Perforation

Characteristics

Total Number = 35

Mean Age

64.0 ± 20.2 years

Gender:

• Male

• 16 (45.7%)

• Female

• 19 (54.3%)

Mean time from implant

35.9 ± 48.8 weeks

Type of device:

• Pacemaker

• 19 (54.3%)

• ICD

• 15 (42.8%)

• NA

• 1 (2.9%)

Type of lead fixation:

• Active

• 24 (68.6%)

• Passive

• 6 (17.1%)

• NA

• 5 (14.3%)

Evidence of Perforation on echocardiography:

• Yes

• 24 (68.6%)

• No

• 4 (11.4%)

• NA

• 7 (20.0%)

(ICD: Implantable cardioverter-defibrillators; NA: Not available). Table includes the analysis of 35 cases reported in the listed references.29,31,32,34-37,41,44,66-84

DELETERIOUS EFFECTS OF RIGHT VENTRICULAR APICAL PACING ON LEFT VENTRICULAR FUNCTION

Fig. 56.8: Three-dimensional echocardiogram of an apical fourchamber view, demonstrating the pacemaker lead tip (arrow) going through the interventricular septum (arrowhead); (LV: Left ventricle; RV: Right ventricle). Source: Reproduced with permission from Daher IN, Saeed M, Schwarz ER, Agoston I, Rahman MA, Ahmad M. Live threedimensional echocardiography in diagnosis of interventricular septal perforation by pacemaker lead. Echocardiography. 2006;23(5):428–9.

Left ventricular mechanical and electrical dyssynchrony are poor prognostic factors in patients with systolic heart failure.45,46 Abnormalities in the timing of regional mechanical left ventricular activation, known as intraventricular dyssynchrony, appears to be the principal factor associated with contractile impairment that is improved by CRT. The classic type of dyssynchrony resulting from abnormal electrical activation is seen with left bundle branch block (LBBB), where there is early activation of the interventricular septum and late activation of the posterior and lateral left ventricular walls.47 The early septal contraction occurs before normal ejection when pressure in the left ventricle is low, thereby generating asynchronous stress and strain in the left ventricle, with one wall exerting forces on the contralateral wall.48 Right ventricular apical pacing is frequently used with implantable pacemakers, and it has been shown to be a well-established risk factor for left ventricular

1218


A

B

Figs 56.9A and B: Three dimensional (3D) segmental time–velocity curves of left ventricle (LV) before pacing, left ventricular ejection fraction (LVEF) 48.5%, SDI 2.7% (A) and after right ventricle (RV) pacing, ejection fraction (EF) 45.7%, SDI 10.9% (B), showing increased LV dyssynchrony and decrease in LVEF after pacing.

dyssynchrony leading to systolic dysfunction.49 Dyssyn chrony with RV pacing has a similar mechanism to LBBB. In the long run, RV pacing and dyssynchrony may trigger ventricular remodeling by causing both systolic and diastolic left ventricular dysfunction, increases in endsystolic volume and wall stress, leading to asymmetrical hypertrophy and abnormal histopathology. Clinically, these changes manifest as worsening of heart failure.48,50,51 Furthermore, one study demonstrated that RV apical pacing can cause regional myocardial perfusion and wall motion abnormalities near the sites of electrical stimulation, which increase with the duration of pacing. These changes are associated with impairment of left ventricular diastolic function and progressive deterioration of regional left ventricular ejection fraction over time in regions remote from the site of electrical stimulation, resulting in a significant reduction in global left ventricular function.52 Left ventricular dyssynchrony can be assessed by tissue Doppler imaging and more recently by speckle tracking echocardiography. Measurements of mechanical dyssynchrony index guide CRT in patients with heart failure and left ventricular dysfunction.53 Real time 3D echocardiography provides a unique and powerful tool for the evaluation of left ventricular dyssynchrony by allowing comparison of the time–velocity curves of the various left ventricular segments in the same cardiac cycle. The impact of RV pacing on left ventricular dyssynchrony is shown in

Figures 56.9A and B.53–57 Patients with RV pacing can be evaluated for left ventricular dyssynchrony and followed over time to detect pacing-related left ventricular systolic dysfunction.

CONCLUSION The increasing indications and uses for implantable cardiac devices have led to a continuous increase in the number of implanted devices each year. Implantation of endocardial leads for these devices can cause many delayed complications. Some of the complications are mechanical and related to the presence of foreign body and its interaction with the valves and endomyocardium, for example, perforation, infection, and thrombosis, while others are related to the electrical pacing of the myocardium and conduction abnormalities, for example, dyssynchrony and TR. It is important to have a high index of suspicion to diagnose these complications, using the appropriate imaging modality. Based on the preceding review, it is clear that echocardiography plays an important role in the diagnosis of the device-related complications. Both 2D TTE and TEE provide extremely useful diagnostic information that is helpful in detecting the endocardial lead-related complications. Real time 3D echocardiography is a novel technique that can precisely track the intracardiac route of the lead and accurately detect most of the pacemaker/ICD lead-related complications.


REFERENCES 1. Uslan DZ, Tleyjeh IM, Baddour LM, et al. Temporal trends in permanent pacemaker implantation: a populationbased study. Am Heart J. 2008;155(5):896–903. 2. Hammill SC, Kremers MS, Kadish AH, et al. Review of the ICD Registry’s third year, expansion to include lead data and pediatric ICD procedures, and role for measuring performance. Heart Rhythm. 2009;6(9):1397–401. 3. Svendsen A. The current status of cardiovascular disease in Canada–a call to action. Can J Cardiovasc Nurs. 2004;14(1): 5–7. 4. Mond HG, Proclemer A. The 11th world survey of cardiac pacing and implantable cardioverter-defibrillators: calendar year 2009—a World Society of Arrhythmia’s project. Pacing Clin Electrophysiol. 2011;34(8):1013–27. 5. Al-Mohaissen MA, Chan KL. Prevalence and mechanism of tricuspid regurgitation following implantation of endo cardial leads for pacemaker or cardioverter-defibrillator. J Am Soc Echocardiogr. 2012;25(3):245–52. 6. Lin G, Nishimura RA, Connolly HM, et al. Severe sympto matic tricuspid valve regurgitation due to permanent pacemaker or implantable cardioverter-defibrillator leads. J Am Coll Cardiol. 2005;45(10):1672–5. 7. Seo Y, Ishizu T, Nakajima H, et al. Clinical utility of 3-dimensional echocar diography in the evaluation of tricuspid regurgitation caused by pacemaker leads. Circ J. 2008;72(9):1465–70. 8. Becker AE, Becker MJ, Claudon DG, et al. Surface thrombosis and fibrous encapsulation of intravenous pace maker catheter electrode. Circulation. 1972;46(2):409–12. 9. Schnabel R, Khaw AV, von Bardeleben RS, et al. Assessment of the tricuspid valve morphology by transthoracic real time 3D-echocardiography. Echocardiography. 2005;22(1): 15-23. 10. Schwartz IS, Pervez N. Bacterial endocarditis associated with a permanent transvenous cardiac pacemaker. JAMA. 1971;218(5):736–7. 11. Arber N, Pras E, Copperman Y, et al. Pacemaker endocarditis. Report of 44 cases and review of the literature. Medicine (Baltimore). 1994;73(6):299–305. 12. Sohail MR, Uslan DZ, Khan AH, et al. Infective endocarditis complicating permanent pacemaker and implantable cardioverter-defibrillator infection. Mayo Clin Proc. 2008;83(1):46–53. 13. Conklin EF, Giannelli S Jr, Nealon TF Jr. Four hundred consecutive patients with permanent transvenous pacemakers. J Thorac Cardiovasc Surg. 1975;69(1):1–7. 14. Bluhm G. Pacemaker infections. A clinical study with special reference to prophylactic use of some isoxazolyl penicillins. Acta Med Scand Suppl. 1985;699:1–62. 15. Moss AJ, Zareba W, Hall WJ, et al.; Multicenter Automatic Defibrillator Implantation Trial II Investigators. Proph ylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med. 2002;346(12):877–83.

1219

16. Mela T, McGovern BA, Garan H, et al. Long-term infection rates associated with the pectoral versus abdominal approach to cardioverter- defibrillator implants. Am J Cardiol. 2001;88(7):750–3. 17. Baddour LM, Bettmann MA, Bolger AF, et al.; AHA. Nonvalvular cardiovascular device-related infections. Cir culation. 2003;108(16):2015–31. 18. Sanfilippo AJ, Picard MH, Newell JB, et al. Echocardiographic assessment of patients with infectious endocarditis: prediction of risk for complications. J Am Coll Cardiol. 1991;18(5):1191–9. 19. Klug D, Lacroix D, Savoye C, et al. Systemic infection related to endocarditis on pacemaker leads: clinical presentation and management. Circulation. 1997;95(8):2098–107. 20. Cacoub P, Leprince P, Nataf P, et al. Pacemaker infective endocarditis. Am J Cardiol. 1998;82(4):480–4. 21. Victor F, De Place C, Camus C, et al. Pacemaker lead infection: echocardiographic features, management, and outcome. Heart. 1999;81(1):82–7. 22. Barakat K, Robinson NM, Spurrell RA. Transvenous pacing lead-induced thrombosis: a series of cases with a review of the literature. Cardiology. 2000;93(3):142–8. 23. Schifter DR, Kozer LM, Saul BI, et al. An unusual case of multiple right atrial thrombi in a patient with a dualchamber pacemaker—a case report. Angiology. 1999;50(10): 855–8. 24. Wierzbowska K, Krzeminska-Pakula M, et al. Symptomatic atrial pacemaker lead thrombosis: detection by echocar diography and successful surgical treatment. Pacing Clin Electrophysiol. 2001;24(3):391–3. 25. Hung MJ, Wang CH, Kuo LT, et al. Large right atrial thrombus with pulmonary embolism. Echocardiography. 2000;17(4):329–34. 26. Nicolosi GL, Charmet PA, Zanuttini D. Large right atrial thrombosis. Rare complication during permanent trans venous endocardial pacing. Br Heart J. 1980;43(2):199–201. 27. The European Cooperative Study on the Clinical Significance of Right Heart Thrombi. European Working Group on Echocardiography. Eur Heart J. 1989;10(12):1046–59. 28. Turakhia M, Prasad M, Olgin J, et al. Rates and severity of perforation from implantable cardioverter-defibrillator leads: a 4-year study. J Interv Card Electrophysiol. 2009;24(1):47–52. 29. Haq SA, Heitner JF, Lee L, et al. Late presentation of a lead perforation as a complication of permanent pacemaker insertion. Angiology. 2008;59(5):619–21. 30. Selcuk H, Selcuk MT, Maden O, et al. Uncomplicated heart and lung perforation by a displaced ventricular pacemaker lead: a case report. Pacing Clin Electrophysiol. 2006;29(4):429–30. 31. Ramirez MF, Ching CK, Ho KL, et al. “The attack of the 52 cm lead”: an unusual case of late cardiac perforation by a passive-fixation permanent pacemaker lead. Int J Cardiol. 2007;115(1):e5–e7. 32. Akyol A, Aydin A, Erdinler I, et al. Late perforation of the heart, pericardium, and diaphragm by an active-fixation ventricular lead. Pacing Clin Electrophysiol. 2005;28(4): 350–1.

1220


33. Carlson MD, Freedman RA, Levine PA. Lead perforation: incidence in registries. Pacing Clin Electrophysiol. 2008; 31(1):13–15. 34. Khan MN, Joseph G, Khaykin Y, et al. Delayed lead perfor ation: a disturbing trend. Pacing Clin Electro physiol. 2005;28(3):251–3. 35. Ellenbogen KA, Wood MA, Shepard RK. Delayed complications following pacemaker implantation. Pacing Clin Electrophysiol. 2002;25(8):1155–8. 36. Refaat MM, Hashash JG, Shalaby AA. Late perforation by cardiac implantable electronic device leads: clinical presentation, diagnostic clues, and management. Clin Cardiol. 2010;33(8):466–75. 37. Polin GM, Zado E, Nayak H, et al. Proper management of pericardial tamponade as a late complication of implantable cardiac device placement. Am J Cardiol. 2006;98(2):223–5. 38. Greenberg S, Lawton J, Chen J. Images in cardiovascular medicine. Right ventricular lead perforation presenting as left chest wall muscle stimulation. Circulation. 2005;111(25):e451–e452. 39. Lloyd MS, Shaik MN, Riley M, et al. More late perforations with the Riata defibrillator lead from a high-volume center: an update on the numbers. Pacing Clin Electrophysiol. 2008;31(6):784–5. 40. Hirschl DA, Jain VR, Spindola-Franco H, et al. Prevalence and characterization of asymptomatic pacemaker and ICD lead perforation on CT. Pacing Clin Electrophysiol. 2007;30(1):28–32. 41. Park RE, Melton IC, Crozier IG. Delayed defibrillator lead perforation. Pacing Clin Electrophysiol. 2008;31(6):785–6. 42. Sassone B, Gabrieli L, Boggian G, et al. Management of traumatic implantable cardioverter defibrillator lead perforation of the right ventricle after car accident: a case report. Europace. 2009;11(7):961–2. 43. Stefanidis AS, Margos PN, Kotsakis AA, et al. Threedimensional echocardiographic documentation of pace maker lead perforation presenting as acute pericarditis. Hellenic J Cardiol. 2009;50(4):335–7. 44. Daher IN, Saeed M, Schwarz ER, et al. Live three-dimen sional echocardiography in diagnosis of interventricular septal perforation by pacemaker lead. Echocardiography. 2006;23(5):428–9. 45. Uretsky BF, Thygesen K, Daubert JC, et al. Predictors of mortality from pump failure and sudden cardiac death in patients with systolic heart failure and left ventricular dyssynchrony: results of the CARE-HF trial. J Card Fail. 2008;14(8):670–5. 46. Chalil S, Stegemann B, Muhyaldeen S, et al. Intraventricular dyssynchrony predicts mortality and morbidity after cardiac resynchronization therapy: a study using cardiovascular magnetic resonance tissue synchronization imaging. J Am Coll Cardiol. 2007;50(3):243–52. 47. Grines CL, Bashore TM, Boudoulas H, et al. Functional abnormalities in isolated left bundle branch block. The effect of interventricular asynchrony. Circulation. 1989; 79(4):845–53. 48. Spragg DD, Kass DA. Pathobiology of left ventricular dyssynchrony and resynchronization. Prog Cardiovasc Dis. 2006;49(1):26–41.

49. Manolis AS. The deleterious consequences of right ventricular apical pacing: time to seek alternate site pacing. Pacing Clin Electrophysiol. 2006;29(3):298–315. 50. Karpawich PP, Rabah R, Haas JE. Altered cardiac histology following apical right ventricular pacing in patients with congenital atrioventricular block. Pacing Clin Electro physiol. 1999;22(9):1372–7. 51. Thambo JB, Bordachar P, Garrigue S, et al. Detrimental ventricular remodeling in patients with congenital complete heart block and chronic right ventricular apical pacing. Circulation. 2004;110(25):3766–72. 52. Tse HF, Yu C, Wong KK, et al. Functional abnormalities in patients with permanent right ventricular pacing: the effect of sites of electrical stimulation. J Am Coll Cardiol. 2002;40(8):1451–8. 53. Wang H, Shuraih M, Ahmad M. Real time three-dimen sional echocardiography in assessment of left ventricular dyssynchrony and cardiac resynchronization therapy. Echocardiography. 2012;29(2):192–9. 54. Søgaard P, Egeblad H, Kim WY, et al. Tissue Doppler imaging predicts improved systolic performance and reversed left ventricular remodeling during long-term cardiac resynchronization therapy. J Am Coll Cardiol. 2002;40(4):723–30. 55. Galderisi M, Cattaneo F, Mondillo S. Doppler echocar diography and myocardial dyssynchrony: a practical update of old and new ultrasound technologies. Cardiovasc Ultrasound. 2007;5:28. 56. Marsan NA, Bleeker GB, Ypenburg C, et al. Real-time threedimensional echocardiography permits quantification of left ventricular mechanical dyssynchrony and predicts acute response to cardiac resynchronization therapy. J Cardiovasc Electrophysiol. 2008;19(4):392–9. 57. Kapetanakis S, Kearney MT, Siva A, et al. Real-time threedimensional echocar diography: a novel technique to quantify global left ventricular mechanical dyssynchrony. Circulation. 2005; 112(7):992–1000. 58. Sakai M, Ohkawa S, Ueda K, et al. [Tricuspid regurgitation induced by transvenous right ventricular pacing: echocar diographic and pathological observations]. J Cardiol. 1987;17(2):311–20. 59. Paniagua D, Aldrich HR, Lieberman EH, et al. Increased prevalence of significant tricuspid regurgitation in patients with transvenous pacemakers leads. Am J Cardiol. 1998; 82(9):1130–2, A9. 60. Leibowitz DW, Rosenheck S, Pollak A, et al. Transvenous pacemaker leads do not worsen tricuspid regurgitation: a prospective echocardiographic study. Cardiology. 2000; 93(1-2):74–7. 61. Kucukarslan N, Kirilmaz A, Ulusoy E, et al. Tricuspid insufficiency does not increase early after permanent implantation of pacemaker leads. J Card Surg. 2006;21(4): 391–4. 62. Kim JB, Spevack DM, Tunick PA, et al. The effect of transvenous pacemaker and implantable cardioverter defibrillator lead placement on tricuspid valve function: an observational study. J Am Soc Echocardiogr. 2008;21(3): 284–7.


63. Klutstein M, Balkin J, Butnaru A, et al. Tricuspid incom petence following perm anent pacemaker implan tation. Pacing Clin Electrophysiol. 2009;32(Suppl 1):S135–S137. 64. Vaturi M, Kusniec J, Shapira Y, et al. Right ventricular pacing increases tricuspid regurgitation grade regardless of the mechanical interference to the valve by the electrode. Eur J Echocardiogr. 2010;11(6):550–3. 65. Alizadeh A, Sanati HR, Haji-Karimi M, et al. Induction and aggravation of atrioventricular valve regurgitation in the course of chronic right ventricular apical pacing. Europace. 2011;13(11):1587–90. 65. Mortensen K, Aydin MA, Goldmann B, et al. Fluoroscopy to assess late heart and lung perforation by a permanent ventricular pacemaker lead. A case complicated by isolated hemothorax. Int J Cardiol. 2008;128(1):104–6. 67. Krivan L, Kozák M, Vlasínová J, et al. Right ventricular perforation with an ICD defibrillation lead managed by surgical revision and epicardial leads—case reports. Pacing Clin Electrophysiol. 2008;31(1):3–6. 68. Satpathy R, Hee T, Esterbrooks D, et al. Delayed defibrillator lead perforation: an increasing phenomenon. Pacing Clin Electrophysiol. 2008;31(1):10–12. 69. Sakai Y, Sato Y, Matsuo S, et al. Perforation of the right ventricular free wall by an ICD lead in a patient with isolated noncompaction of the ventricular myocardium. Int J Cardiol. 2007;117(3):e104–e106. 70. Lopes LR, Brandão L, Carrageta M. Single-step transvenous extraction of a passive fixation lead with delayed perforation of the right ventricle. Europace. 2007;9(8):672–3. 71. Toal SC, Nanthakumar K. Injury potential as a diagnostic tool for implantable cardioverter-defibrillator lead perfo ration. Heart Rhythm. 2007;4(3):381. 72. Laborderie J, Bordachar P, Reuter S, et al. Myocardial pacing lead perforation revealed by mammary hematoma next to the device pocket. J Cardiovasc Electrophysiol. 2007;18(3):338. 73. Sanoussi A, El Nakadi B, Lardinois I, et al. Late right ventricular perforation after permanent pacemaker impla ntation: how far can the lead go? Pacing Clin Electrophysiol. 2005;28(7):723–5.

1221

74. Kautzner J, Bytesník J. Recurrent pericardial chest pain: a case of late right ventricular perforation after implantation of a transvenous active-fixation ICD lead. Pacing Clin Electrophysiol. 2001;24(1):116–8. 75. Amara W, Cymbalista M, Sergent J. Delayed right ventricular perforation with a pacemaker lead into subcutaneous tissues. Arch Cardiovasc Dis. 2010;103(1):53–4. 76. Haghjoo M, Alizadeh A, Fazelifar AF, et al. Delayed cardiac perforation by one small body diameter defibrillator lead. J Electrocardiol. 2010;43(1):71–3. 77. Ferrero-de-Loma-Osorio A, Albors-Martín J, Ruiz-Granell R, et al. Images in cardiovascular medicine: Delayed right ventricular perforation by a transvenous active fixation implantable cardioverter-defibrillator lead: echo cardio graphic diagnosis and surgical management. Circulation. 2009;119(15):2112–13. 78. Tziakas D, Alexoudis A, Konstantinou F, et al. A rare case of late right ventricular perforation by a passive-fixation permanent pacemaker lead. Europace. 2009;11(7):968–9. 79. Danik SB, Mansour M, Heist EK, et al. Timing of delayed perforation with the St. Jude Riata lead: a single-center experience and a review of the literature. Heart Rhythm. 2008;5(12):1667–72. 80. Celik T, Kose S, Bugan B, et al. Hiccup as a result of late lead perforation: report of two cases and review of the literature. Europace. 2009;11(7):963–5. 81. Haque MA, Roy S, Biswas B. Perforation by permanent pacemaker lead: how late can they occur? Cardiol J. 2012;19(3):326–7. 82. Hörer J, Will A, Schreiber C. Delayed right-ventricular perforation of a pacemaker lead. Pediatr Cardiol. 2011;32(5): 708–9. 83. Bigdeli AK, Beiras-Fernandez A, Kaczmarek I, et al. Succ essful management of late right ventricular perforation after pacemaker implantation. Vasc Health Risk Manag. 2010;6:27–30. 84. Fisher JD, Fox M, Kim SG, et al. Asymptomatic anterior perforation of an ICD lead into subcutaneous tissues. Pacing Clin Electrophysiol. 2008;31(1):7–9.

CHAPTER 57 Echocardiographic Evaluation of Ventricular Assist Devices Peter S Rahko

Snapshot  Clinical Uses of Ventricular Assist Devices  Reverse Remodeling  Types of Devices  PreoperaƟve Echocardiographic EvaluaƟon  Immediate Postsurgical EvaluaƟon  Serial Changes in Cardiac Structure and FuncƟon

INTRODUCTION Mechanical circulatory support began in the 1960s when Michael DeBakey and his colleagues first began conceiving of a left ventricular assist device (LVAD). Early devices were pneumatic with an external drive system, and the first device was implanted in 1963 in a patient who suffered a cardiac arrest. By 1966, a second pneumatic, pulsatile LVAD was developed and utilized in a patient.1,2 Considerable development in pulsatile LVADs, namely, devices that had a chamber that filled and then ejected using a pusher plate design, expanded throughout the 1970s and into the 1980s. The first Food and Drug Administration (FDA)-approved intracorporeal LVAD was the Thoratec HeartMate XVE. Initially, it was pneumatically powered but later became electrically powered. This was the first realistic device that gave patients independence since everything was internal except a driveline that came out from a skin tunnel, and attached to a controller and battery pack. For the first time, patients could be relatively mobile and realistically go home and even go back to work in some situations. The superiority of device therapy over medical therapy was established in the REMATCH trial for end-stage heart failure patients.3 However, the pulsatile chamber–pusher plate design had many moving parts,

 ComplicaƟons of LeŌ Ventricular Assist Devices  Evidence of Underfilling of the LeŌ Ventricle  OpƟmizing LeŌ Ventricular Assist Device Seƫngs  ExplantaƟon  Percutaneous ConƟnuous Flow Devices

required heart valves at the inflow and outflow cannulas, and thus had many possibilities for failure. Furthermore, the device was never conceived of as anything but a bridge to transplantation; thus, very long-term utilization of the device was not feasible. Finally, the device was relatively large and could only be implanted in full-sized adults. To address the shortcomings of pulsatile devices, the concept of a continuous flow assist device was developed. These rotary pumps use the principle of the Archimedes screw. Pump rotation creates force on blood and propels it forward longitudinally through the device. The impeller of this device must rotate at a relatively faster speed (8,000– 12,000 rpm) to create a moving force on the blood. The advantage of this design is a marked reduction in overall size. Indeed, it was possible to miniaturize these devices to the point that there was a marked improvement in tolerability and also an expanded range of body size that could benefit from this device. The first clinical use of a device of this type occurred in 1998 with the introduction of the MicroMed DeBakey VAD. The first approved device by the FDA was the HeartMate II built by Thoratec Corporation (Figs 57.1A to D).4 The third generation of assist devices is centrifugal (Figs 57.2A to D). These devices propel blood like a spinning top inside of a chamber. Blood enters the device

Chapter 57: Echocardiographic Evaluation of Ventricular Assist Devices

A

B

C

D

1223

Figs 57.1A to D: (A) The Thoratec HeartMate II draws blood from the left ventricle (LV) apex through the inflow cannula into the pump and then ejects blood through the outflow cannula to the central aorta; (B) Closer view showing the impellar design. (Used with permission of Thoratec); (C) Chest X-ray of patient with a HeartMate II showing inflow cannula position and relative position of the left ventricular assist device (LVAD) in the chest; (D) Three-dimensional reconstruction of a chest CT scan of same patient as (C). Note position of cannula and in this case the tortuous course of the outflow cannula.

A Figs 57.2A and B

B

1224


C

D

Figs 57.2A to D: Example of a centrifugal pump, the HeartWare device. (A) Relative size is small; (B) The device open shows the rotating disk that spins blood outward from the center; (C) Diagram showing relative location of device at the left ventricle (LV) apex and the outflow cannula to the central aorta; (D) View showing relative location in the chest of the components of the device. Source: Used with permission from HeartWare International.

Fig. 57.3: The Abiomed Impella is moved retrograde from the femoral artery to the central aorta and across to the left ventricle. Blood is pulled from the left ventricle (LV) cavity by the Impella and ejected into the central aorta. Source: Used with permission from Abiomed.

at the center, where the spinning generates a vortex of low pressure, with progressively higher pressures as one reaches the outside of the spinning disk. These devices typically rotate between 2,000 and 3,000 rpm. The first clinical application of a third generation device occurred in 2005 with implantation of the VentrAssist.4

CLINICAL USES OF VENTRICULAR ASSIST DEVICES Ventricular assist devices have multiple uses for multiple clinical circumstances. The original devices were

conceived as bridge to recovery devices to allow temporary support of patients expected to recover from a temporary but severe clinical situation. Devices designed for this purpose are in clinical use today and typically are percutaneously deployed rapidly in urgent situations. These devices provide a greater level of assist and output response than an intra-aortic balloon pump. Devices may be small, impeller-type systems such as the Impella series of recovery devices (Abiomed) designed for very shortterm use, or the TandemHeart (Cardiac Assist), which is an extracorporeal centrifugal flow pump. This device may also be used for relatively brief periods of time (Figs 57.3 and 57.4). Long-term assist devices are now predominantly axial flow devices or centrifugal pumps. These devices may be directly implanted in individuals who are severely ill or in individuals who are chronically severely debilitated and require emergent, urgent, or elective placement of the device. The most detailed data on the use of these devices comes from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS).5 INTERMACS has defined seven different profiles of patients based upon clinical severity and is tracking these patients over time to determine outcomes. Ongoing evaluation of patients having these devices placed will help determine best practices. The basic INTERMACS profiles are shown in Table 57.1. As assist devices have evolved, so have indications. Bridge to recovery is predominantly confined to acute devices, with the larger devices showing only very


A

1225

B

Figs 57.4A and B: (A) The TandemHeart device. An inflow catheter is inserted in a femoral vein and moved up to the right atrium and then across to the left atrium. Blood is removed from the left atrium outside to the pump and then via the outflow cannula ejected into the central aorta; (B) Closer look at ideal position of the inflow cannula. Note there are 14 side holes and 1 end-hole. Source: Used with permission from Cardiac Assist, Inc.

Table 57.1: Classification of Levels of Severity of Patients who are Potential Candidates for a Ventricular Assist Device: The Interagency Registry for Mechanical Assisted Circulatory Support (INTERMACS)

Profile Percentage of Implants* Profile Name

Profile Description

1

16

Critical Cardiogenic Shock

Life threatening despite inotropic support, hypotensive, and hypoperfused

2

38

Progressive Decline

Declining systemic function, nutrition, and renal function despite inotropic support

3

28

Staple Inotropic Dependent Achieved stable blood pressure, organ perfusion, and nutrition but unable to be weaned from inotropic or other temporary mechanical support

4

12

Resting Symptoms

Stable with normal volume status on oral medications. Daily symptoms of limiting congestion at rest or with minimal activity

5

3

Exercise Intolerant

No symptoms with rest or minimal activity. All other activity causes congestion. Frequent episodes of volume overload

6

2

Exertion Limited

No resting symptoms. No fluid overload. Minimal activity can be performed but fatigues in a few minutes

*Percentage of implants for the year 2011. Source: Adapted from INTERMACS, accessed at www.intermacs.org January 27, 2013.

1226


Table 57.2: Frequency of Ventricular Assist Device Implantation by Device Strategy: The INTERMACS Registry

Device Use Strategy

Implant Year 2007

2009

2011

Bridge to Transplant

147 (42%)

505 (49%)

424 (22%)

Bridge to Candidacy

134 (38%)

432 (42%)

695 (37%)

Destination Therapy

48 (14%)

59 (6%)

742 (39%)

Bridge to Recovery

14 (4%)

13 (1%)

17 (1%)

Other

8 (2%)

11 (1%)

20 (1%)

351

1,020

1,898

Total Implants

Source: Adapted from INTERMACS, accessed at www.intermacs.org January 27, 2013.

modest use for this indication. With greater longevity of use, indications have expanded into several other large categories. Bridge to transplant is for patients who are expected not to survive until a transplant becomes available. As the demand for transplants has increased but the availability has remained static or actually slightly decreased, the waiting time for a heart transplant continues to prolong. Thus, bridge to transplant now requires longterm support of these newer devices. The success of bridge to transplantation has led to considerations for use of these devices as an ultimate end in itself. This is called destination therapy. Patients in this category are not candidates for cardiac transplantation but are candidates for prolonged assist to help improve longevity and quality of life. A final major category is called bridge to candidacy. These patients typically, at the time of evaluation, are found not to be candidates for transplantation. However, the impediment to transplantation may not be permanent and could be reversed by ongoing therapy. Thus, there is a possibility that these patients might be listed in the future for transplantation. If this occurs, the patient reverts to bridge to transplantation. If this does not ever occur, the patient reverts to destination therapy. Current data from INTERMACS, as of September 30, 2012, lists 7,290 patients in the registry. In 2007, during the first full year of the registry, bridge to transplant was the most frequent reason for placement of an LVAD. Over the next 2 years, bridge to transplant and bridge to candidacy were the predominant reasons for LVAD implantation. With changes in approval of devices, 2010 saw a dramatic increase in destination therapy, and in 2011 destination therapy became the most frequent indication for an LVAD. The relative frequency of these categories of implantation is shown in Table 57.2 for selected years.5

REVERSE REMODELING Placement of a LVAD generally causes significant reverse remodeling. While it was hoped initially that substantial reverse remodeling would include both volumetric reduction and functional improvement, to the point that the LVAD might be removed, later studies in wide varieties of individuals have shown that the ability to explant an LVAD is relatively uncommon.6 In an analysis of neurohormonal blood levels in patients with LVADs, some studies have shown a decline in levels of endothelin-1 and B-type natriuretic peptide associated with some improvement in function. Analysis of myocardium taken from the core sample at the time of LVAD placement and then at the time of either explantation or transplantation has shown improvements in cardiac myocytes. In particular, there has been regression of cardiac cell hypertrophy and reduction in overall size. In addition, there has been evidence of a reduction in total collagen back toward control levels. Replacement fibrosis for dead myocytes generally does not revert, but the interstitium may change favorably with unloading from the LVAD. Unfortunately, these positive changes in matrix and myocytes have generally not been translated into enough improvement to allow explantation.7,8

TYPES OF DEVICES Short-Term Circulatory Support Short-term devices are indicated for patients with acute cardiogenic shock or postcardiotomy shock, which could involve the left ventricle, right ventricle, or both. In some circumstances, these devices may be placed prior to performing a high-risk percutaneous intervention.


1227

Impella Catheter-Based Assist Device

Abiomed AB5000

This device is a continuous flow system that is quite small and can be placed percutaneously across the aortic valve or pulmonic valve. It is a continuous flow device designed to provide partial circulatory support for up to 6 hours. The output of the smaller version is about 2.5 L/min. The inlet area of the device sits in the ventricle, pulling blood out of the ventricle and ejecting it on the other side of the valve into the central aorta or pulmonary artery. The pump is 12 Fr in diameter. A positive response to placement of this device consists of (1) a reduction in filling pressure within the ventricle, (2) a reduction in mechanical work and wall tension that reduces oxygen demand, and (3) an improvement in cardiac output increasing oxygen supply to the periphery. A larger version using a 21 Fr pump motor is the Impella 5, capable of 5 L/min of output (see Fig. 57.3).9

This is a first generation pulsatile assist device. It is designed for short-term support. The cannulas are surgically implanted and the device may be used in LVAD, right ventricular assist device (RVAD), or biventricular assist device (BiVAD) configurations. It is a bridge to recovery or bridge to decision device.

TandemHeart System The TandemHeart is an extracorporeal centrifugal pump. The inflow catheter is inserted via a femoral vein, up the vena cava and into the right atrium, and then via transseptal puncture placed in the left atrium. The device removes oxygenated blood from the left atrium, out of the body to the external pump, which then returns this blood via a femoral artery into the central aorta. The inflow catheter has 14 side holes and an end hole. Transesophageal echocardiography is used by some operators to help assist in trans-septal puncture and placement of the inflow catheter. The TandemHeart has been compared to intra-aortic balloon pulsation in patients presenting with cardiogenic shock. The hemodynamic effects of the TandemHeart appear to be superior (see Figs. 57.4A and B). However, overall mortality was not reduced.10

Thoratec CentriMag System This device is a magnetically levitated centrifugal pump that is extracorporeal. It comes in an adult and pediatric version, and can be used for up to 30 days as a bridge to decision for cardiogenic shock of either the right or left ventricle. It has been approved for use in various formats in several countries. This device has the capability of producing up to 10 L/min of flow and can be configured to provide left ventricular, right ventricular, or biventricular support, and also can be configured to work with an extracorporeal membrane oxygenator (ECMO) circuit.11 It does require a sternotomy and surgical placement of the cannulas.

Thoratec Paracorporeal Ventricular Assist Device This device can be used as an external or internally implanted device. The device has been available since the 1990s, approved for patients with end-stage heart failure as a bridge to cardiac transplantation or for postcardiotomy support. The device is a pneumatic-driven, pulsatile device.

Long-Term Axial Flow Devices For all of these devices, output across the LVAD is determined by three major factors: (1) pump rotation speed, (2) LVAD “preload”, and (3) LVAD afterload. Factors (1) and (2) are inter-related and determine the pressure differential across the pump. For a given rotational speed, flow across the pump increases as the pressure differential across the pump declines. For example, consider a patient under two circumstances: a mean arterial pressure of 55 mm Hg versus a mean pressure of 80 mm Hg. In the former situation, particularly during diastole, the LV–aorta pressure differential is relatively small and pump flow will be higher, giving the patient a higher systemic output. Doppler flow velocity, both inflow and outflow, will be higher. As aortic pressure rises, if all other things stay the same, pump flow declines. The most significant determinant of LVAD “preload” is residual contractility of the LV. During systole, a larger pressure rise in the LV will decrease the LV–aorta pressure difference and propel more blood forward. The patient will demonstrate greater pulsatility and a greater degree of flow velocity during systole in both the inflow and outflow cannula. The degree to which the aortic valve opens shows the relative amount of time in which the cardiac cycle LV systolic pressure exceeds aortic pressure. This will be an independent contributor to pulsatility. All long-term axial devices share a relatively similar configuration. The inflow cannula is at the left ventricular apex and the pump is in series with the cannula. Blood flow

1228


12,500 rpm, and can generate flow as high as 10 L/min. A pediatric version has also been developed.

Jarvik-2000 FlowMaker The pump is different from other axial flow devices in that there is no inflow cannula. The pump is directly implanted in the apex of the left ventricle but can also be used in the right ventricle. This pump is also relatively small at 90 g (Fig. 57.5).

Long-Term Third Generation Centrifugal Flow Systems These devices represent the newest design for LVADs. They operate at lower speeds than axial pumps and may have a longer life expectancy than the axial flow models. Configuration with the heart is similar to that of the axial flow system. Current examples of these devices are discussed below. Fig. 57.5: Diagram of the placement of the Jarvik-2000 Flowmaker. The device has no inflow cannula; it is inserted directly into the left ventricular apex. Source: Used with permission from Jarvik Heart.

is boosted by the pump and returned to the aorta, usually the ascending segment. The lifespan of these devices is projected for several years (see Fig. 57.1). Some examples of current devices are discussed below.

Berlin Heart INCOR Assist Device This pump is an axial flow pump with a magnetically levitated impeller. The pump provides flow of up to 6 L/ min at a speed of 7,500 rpm. This device is manufactured by Berlin Heart.

HeartMate II Continuous Flow Left Ventricular Assist Device This system is manufactured by Thoratec and is an axial flow pump that is electrically driven. The rotor is suspended between the inlet and outlet sites with ball bearings. This device has been used for bridge to transplant, bridge to decision, and destination therapy (see Fig. 57.1).

HeartAssist System This is an axial flow pump that is relatively small, being only 95 g in weight. The device rotates between 7,500 and

HeartWare Ventricular System This device is a centrifugal pump with blood flow coming into the center of the device and exiting from the periphery. The pump is designed to be implanted entirely in the pericardial space, without the need for any secondary pocket. The device is inserted directly onto the apex, with a very short inflow cannula. The outflow cannula is placed at the central aorta (see Fig. 57.2).

DuraHeart Magnetically Levitated Centrifugal Assist System This is a third generation system with no mechanical contacts; instead, it uses magnetic levitation between the impeller and pump housing. The device is attached via a cannula to the left ventricle, and outflow goes to the central aorta.

Levacor Ventricular Assist Device This is a centrifugal device operating between 800 and 3,000 rpm, providing flows up to 9 L/min.

EvaHeart Left Ventricular System This is a larger centrifugal pump implanted into the left abdominal wall, weighing 420 g. The device output depends on head pressures within the pump similar to


1229

Table 57.3: Partial List of Ventricular Assist Devices

Name

Manufacturer

Pump Type

Inflow/Outflow Anatomic Site

Speed Range

Current Usage

axial/ catheter based

LV/aorta RV/PA

25–50 K (2.5) 10–30 K (5)

Short-term up to 6 hours

LA/femoral artery

3–7.5 K

Short-term up to 30 days

Percutaneous Placement for Short-Term Support Impella

Abiomed (Danvers, MA)

TandemHeart

Cardiac Assist, Inc. (Pitts- centrifugal/extracorporeal burgh, PA)

Short-Term Support (surgical placement) Abiomed AB5000

Abiomed (Danvers, MA)

Pulsatile/extracorporeal

LV apex/aorta RA/ PA

Pulsatile

Short-term support up to 30 days

CentriMag

Thoratec Corp. (Pleasanton, CA)

Centrifugal/extracorporeal

LV apex/aorta RA/ PA BiVAD, ECMO

0–5.5 K

Up to 30 days support

Incor

Berlin Heart (Berlin, Germany)

Axial/intracorporeal

LV apex/aorta

7.5 K

Long-term support

HeartMate II

Thoratec Corp (Pleasanton, CA)


LV apex/aorta

6–15 K

Long-term support

HeartAssist 5

MicroMed Technology (Houston, TX)


LV apex/aorta

7.5–12.5 K

Long-term support

Jarvik 2000

Jarvik Heart (New York, NY)


LV apex/aorta RV/ PA BiVAD

8–12 K

Long-term support

HeartWare HVAD

HeartWare International (Framingham, MA)

Centrifugal/intrapericardial LV apex/aorta

1.8–4 K

Long-term support

DuraHeart

Terumo Med Corp. (Somerset, NJ)

Centrifugal/intrapericardial LV apex/aorta

1.2–2.4 K

Long-term support

Levacor

World Heart Inc. (Salt Lake City, UT)

Centrifugal/intracorporeal

LV apex/aorta

1–3 K

Long-term support

EvaHeart

Sun Medical Technology (Naguno, Japan)

Centrifugal/intracorporeal

LV apex/aorta

1–2.8 K

Long-term support

Long-Term Support

(LV: Left ventricle, PA: Pulmonary artery, BiVAD: Biventricular assist device, ECMO: Extracorporeal membrane oxygenator; RA: Right Atrium).

axial devices. The greater the pressure differential between LV and central aorta, the lesser the flow that goes through the pump. On the other hand, when the LV contracts in systole, the pressure between LV and aorta falls, facilitating more pump flow. In this way, even though a continuous flow device is used, the patient maintains a degree of pulsatility.12 A summary of more commonly available devices is listed in Table 57.3. Not all devices are universally available.

PREOPERATIVE ECHOCARDIOGRAPHIC EVALUATION Once clinical criteria have been established that suggest a ventricular assist device may be necessary, a

comprehensive echocardiogram should be performed to further refine information about the patient’s candidacy. It is important that a full, comprehensive echocardiogram be performed, with full two-dimensional (2D) views from all standard imaging planes, along with color Doppler, pulsed wave, and continuous wave Doppler assessment, and appropriate dimension measurements. In some circumstances, three-dimensional (3D) imaging may help further define potential abnormalities, and the use of contrast may be necessary to fully define structures and function.13,14

Left Ventricle The left ventricle should be carefully examined with full long-axis and short-axis imaging. Particular attention

1230


A

B

Figs 57.6A and B: Two examples of apical thrombi. (A) Large thrombus is easily seen in the apical region of the ventricle; (B) This thrombus was not apparent with routine imaging but was much better characterized with contrast.

Fig. 57.7: Severe dilated cardiomyopathy baseline study. Dimensions serve as a frame of reference for serial follow-up after placement of the device. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

Fig. 57.8: Apical four-chamber view of the heart. The septal contour preleft ventricular assist device (LVAD) is rightward and left atrial volume is markedly increased. (LA: Left atrium; LV: Left atrium; RA: Right atrium; RV: Right ventricle).

should be paid to the left ventricular apex. Care should be taken to determine if there is any evidence of a possible thrombus in the apex since this part of the heart will be cored out for attachment of the inflow cannula (Figs 57.6A and B). In addition, characterization of the apex for any unusual shape changes or trabeculations is of value to the surgeon. If there is a question about visibility of endocardial ventricular function or the apex, contrast agents should be used to enhance visualization. Careful 2D dimensions should be measured from the parasternal long-axis view to document overall ventricular size at enddiastole and end-systole, and also wall thickness. These values will serve as a baseline for serial evaluation of the patient after placement of the ventricular assist device

(Fig. 57.7). The ejection fraction should be quantified; typically, patients qualifying for ventricular assist devices should have a severely reduced ejection fraction of < 30%. Views should be obtained in both short-axis and apical views to adequately define the baseline contour of the septum so that changes in septal shape can be judged appropriately after placement of the LVAD (Fig. 57.8). The apex should also be assessed in ischemic heart disease patients for the possibility of an apical aneurysm. An evaluation of diastolic performance is also important as a baseline. Full diastolic evaluation including mitral inflow patterns and velocities, tissue Doppler evaluation of the medial and lateral mitral annulus, and pulmonary vein inflow should be recorded.


1231

Fig. 57.9: Example of a patient with severe mitral regurgitation due to papillary muscle dysfunction. In most cases, severe mitral insufficiency is not a contraindication for left ventricular assist device (LVAD) placement. In many patients, decompression of the left ventricle (LV) improves coaptation. (RV: Right ventricle).

Fig. 57.10: Aortic valve (AV) with significant calcification and on evaluation was severely stenotic.

Left Atrium

of calcification, stenosis, or significant insufficiency could create significant problems for this device and result in ineffective support (Fig. 57.10). For placement of standard apical continuous flow devices, baseline evaluation of the aortic valve is also critical. Careful evaluation of the leaflets should be performed in short-axis views, and in some circumstances might be enhanced by 3D views to determine how much sclerosis, calcification, and leaflet motion restriction is present. Forward flow velocities should be quantified, and if there is any evidence of aortic stenosis, this should be calculated and quantified. Most importantly, the severity of aortic insufficiency should be fully quantified. Patients with more than mild aortic insufficiency could be at substantial risk if the valve is left alone. If significant stenosis is present, the valve may need to be replaced, since the patient could be put at substantial risk if the LVAD suddenly failed.

It is important to assess the size of the left atrium. This is best done by evaluating left atrial volume from a biplane volume calculation (see Fig. 57.8). In some cases, it may also be necessary to evaluate the left atrium and the left atrial appendage with transesophageal echocardiography if there is a strong suspicion of a thrombus in the atrial chambers.

Mitral Valve The mitral valve morphology should be evaluated. LVADs are contraindicated in patients with significant mitral stenosis. This is readily evaluated by Doppler flows across the mitral valve. The motion of the leaflets should be determined and the severity of mitral regurgitation evaluated (Fig. 57.9). In most circumstances, mitral regurgitation will be expected to improve with decompression of the left ventricle after placement of the LVAD. Appropriate quantification of the severity of mitral insufficiency preoperatively helps establish a baseline to evaluate the effect of the LVAD after it is implanted.

Pericardium The pericardium should be assessed to determine if any significant effusion is present or if there is any evidence that suggests the presence of constriction.

Aortic Valve Aortic valve anatomy and function is particularly important if the temporary impeller device is to be utilized. This device works well if the aortic valve is normal, but presence

Atrial Septum The atrial septum is an important structure, particularly since relative filling pressures may change dramatically

1232


A

B

Figs 57.11A and B: (A) Dilated cardiomyopathy with small secundum atrial septal defect (ASD) with shunt shown in orange going left to right. This was not detected in the past and may be due to stretching open of the foramen caused by chamber enlargement; (B) Different patient with heart failure and a larger atrial septal defect. Note large orange left to right shunt jet. Both require closure during left ventricular assist device (LVAD) surgery.

after placement of the LVAD. The patient should be evaluated for the possibility of a patent foramen ovale in the preoperative assessment. Careful evaluation of the atrial septum from multiple views, particularly the subcostal view, may detect shunting. In some circumstances with very large hearts and persistently high filling pressures, a previously patent foramen ovale may stretch out, allowing a left-to-right shunt to be present (Figs 57.11A and B, Movie clips 57.1 to 57.3). This is usually readily quantified in the subcostal view. If no color flow abnormalities are present, a bubble study should be performed with injection of agitated saline intravenously. This should be done with and without Valsalva. Careful attention should be paid to an assessment of left atrial filling pressures. In some circumstances, there may be such a differential between left and right atrial pressures that even a Valsalva maneuver may be ineffective in detecting a patent foramen ovale. If there is a question about the presence of a foramen ovale, a transesophageal echo can be considered for further evaluation. Unusual anatomy of the atrial septum, such as a large atrial septal aneurysm or substantial lipomatous hypertrophy of the atrial septum, could affect the trans-septal puncture necessary for placement of the TandemHeart. If need be, transesophageal echocardiographic guidance may be necessary to help placement of a device.

Aorta Examine as much of the aorta as possible. Off-axis views may be of value to show as much of the ascending aorta as

can be demonstrated. Size of the annulus, sinus of Valsalva, sinotubular junction, and proximal ascending aorta should be determined and as much of the aorta examined as possible for the possible presence of atherosclerosis that might affect placement of the cannula. Suprasternal views of the arch should also be performed and subcostal views can be obtained to evaluate the upper abdominal aorta. The presence of an untreated ascending aortic aneurysm > 5 cm in diameter is considered a contraindication.

Tricuspid Valve The tricuspid valve can pose particular challenges in the perioperative period. Careful evaluation of the severity of tricuspid valve insufficiency is essential from all standard views. Characterization of leaflet motion and morphology, along with measurement of the diameter of the annulus, can be of considerable help to the surgeon in determining whether or not tricuspid valve repair is indicated during the procedure (Figs 57.12A to D and Movie clips 57.4 and 57.5).15–17

Pulmonic Valve The pulmonic valve should be evaluated to exclude any unknown stenosis and also carefully evaluated to determine if there is any significant pulmonic valve insufficiency. This is particularly important in patients who may have underlying congenital disease. Substantial amounts of pulmonic valve insufficiency could contribute to right ventricular overload following placement of the LVAD.


A

B

C

D

1233

Figs 57.12A to D: Tricuspid valve. (A) Valve morphology shows evidence of mild leaflet thickening and reduced excursion due to right ventricle (RV) enlargement and dysfunction; (B) Severe valve insufficiency is present; (C) Coaptation is severely compromised, leaving a visible regurgitant orifice (arrow); (D) The annulus is markedly dilated. This patient had tricuspid valve repair when the left ventricular assist device (LVAD) was placed. (LV: Left ventricle; RA: Right atrium).

Inferior Vena Cava The inferior vena cava should be imaged and its diameter measured, and an evaluation of estimated central venous pressure made. This, combined with the tricuspid regurgitant jet, can be used to assess the severity of pulmonary hypertension. This is particularly important if there is disproportionate elevation of pulmonary pressures that might indicate independent pulmonary artery disease or reactive pulmonary hypertension.

Right Ventricle Perhaps the most difficult and perplexing pre-LVAD evaluation is that of the right ventricle. The concern is

always that of how the ventricle will respond during surgery and how it will respond to placement of the LVAD after the fact. Will the ventricle maintain good function and not be a limiting factor on the patient’s overall cardiac output and functional performance, or will it deteriorate and become the rate limiting structure that controls rightsided congestion and cardiac output? Significant right ventricular heart failure occurs in 20–30% of post-LVAD patients. Survival is reduced in right heart failure patients, morbidity is increased, and length of stay prolonged.18,19 Frequently, clinical characteristics of patients do not differ between those who do well post-LVAD and those who develop right ventricular failure. Detailed assessment of the right ventricle is important and frequently overlooked

1234


in standard echocardiographic evaluations. A special effort should be made to characterize right ventricular size and function from multiple views, particularly apical, subcostal, and short-axis views. As 3D imaging improves, better transthoracic assessment of the right ventricle may be possible in the future. Because the right ventricle is so difficult to evaluate, a large number of proposed tests, measurements, ratios, fractional changes, excursion measurements, indices, and point score systems have been proposed (Figs 57.12 to 57.14 and Movie clip 57.6). No one measurement is foolproof and no particular measurement is considered a gold standard. Table 57.4 summarizes only echocardiographic-based measurements, including a point score system based on left-sided measurements. The point score system is a single center study that uses simple LV measurements. This study suggests that smaller LV size with better preserved LV systolic function but higher levels of filling pressures (represented by the larger LA) are more likely associated with a worse RV prognosis.26 Table 57.5 is an overall summary of the preoperative echocardiographic assessment.

IMMEDIATE POSTSURGICAL EVALUATION Immediate postoperative evaluation is generally performed by the cardiac anesthesiologist after the patient comes off the pump.29 The immediate surgical results of the LVAD placement should be evaluated, along with the response of the ventricles and valves. Before the assist device is activated, an immediate evaluation for residual air bubbles is undertaken in the ventricular chambers, ascending aorta, and cannulas. Activation of the LVAD should begin appropriate unloading and should result in a slight change in interventricular and intra-atrial septum contours to the left. Lack of effective decompression will result in substantial rightward deviation of the septum, indicating suboptimal support from the assist device or inadequate settings to unload the left ventricle. This may require rapid assessment of LVAD function and the device cannulas. The opposite can also occur. Extreme leftward shift of the septum suggests the possibility of an excessively high pump speed that may be unloading the left side too vigorously. It could also be caused by right ventricular dysfunction; thus, right ventricular function should be assessed immediately along with tricuspid valve performance, particularly for severity of tricuspid regurgitation. An immediate concern

in this situation is whether or not right ventricular function is adequate to sustain an adequate cardiac output in the immediate postoperative setting (Fig. 57.15). Another potential issue, particularly if there is leftward deviation of the atrial septum, is the evaluation for a patent foramen ovale. A large right-to-left shunt could cause significant hypoxemia. Sometimes this is missed in the preoperative assessment due to excessively high leftsided pressures. If the preoperative contrast bubble study is abnormal and suggests a significant right-to-left shunt, consideration needs to be given for closure of the patent foramen ovale during the procedure.30 The inflow and outflow cannulas are inspected. The inflow cannula should be inspected to determine the orientation. It should be angled toward the mitral valve and aligned with the left ventricular outflow tract. Doppler evaluation should be performed. A normally functioning inflow cannula generally has relatively low velocity laminar color Doppler flow with low velocities by pulsed wave Doppler. Flow signals deviating from this should raise suspicion about possible obstruction or pump malfunction. Particularly concerning would be a regurgitant flow signal at the site of the cannula, indicating backflow through the pump. One exception is the Jarvik-2000. The pump is actually in the LV apex. The outflow cannula is generally visible in high esophageal views and should show relatively low velocities outward from the cannula (Figs 57.16A and B).

SERIAL CHANGES IN CARDIAC STRUCTURE AND FUNCTION Ventricular Size and Function The echocardiography laboratory and the heart failure program should set up a regular schedule for evaluation of patients with an LVAD. This allows for regular surveillance of effectiveness of the device and for serial changes in performance of the device. A suggested schedule could be month 1, month 3, month 6, month 12, and every 6 months thereafter. A comprehensive study should be performed similar to a regular echocardiographic exam. As many normal views as is possible should be obtained, realizing that all views may not be available. Certain specialized views are also necessary; some of these are outlined in Figure 57.17.30,31 The left ventricle should be assessed particularly for changes in size and function. The expected response to placement of an outflow tract device would be a


1235

Table 57.4: Evaluation of the Right Ventricle: Factors that May Impact Response to Placement of Left Ventricular Assist Device

Factors

Comment

Tricuspid Valve Severity of regurgitation (Fig. 57.12)

May identify patients who would benefit from tricuspid valve repair. Repair may have a survival benefit, recovery benefit, and RV function benefit.15,16,18–21

Size of annulus diameter (Fig. 57.12)

Annular diameter > 43 mm is associated with reduced survival.17

Duration of tricuspid regurgitation in systole (Fig. 57.13)

A rate corrected value of less than 461 ms indicates a worse 2-year prognosis.22

Right Ventricular Function Semiquantitative evaluation of function

Severe systolic dysfunction associated with worse outcome.23

Fractional area change

Values < 20% are associated with increased risk of post LVAD RV dysfunction.24

TAPSE (Fig. 57.14)

Annular motion < 7.5 mm predicts post LVAD RV failure.25

Right Ventricular Geometry Short-axis/long-axis ratio of the RV

Ratio > 0.6 associated with worse outcome

RVEDD/LVEDD ratio (by transesophageal echocardiography) Ratio > 0.72 associated with adverse outcome.17,26 Right-sided Hemodynamics Central vanous pressure (CVP)

Elevated pressure and ratio of CVP to PCWP > 0.64 associated with worse outcome.19

Estimated RV systolic pressure

Conflicting findings, higher25 or lower27 RV systolic pressure associated with worse outcome.

Left ventricle parameters point score system for predicting RV failure after LVAD Parameter

The point score system for detecting RV failure showed the following performance.28

Points

LVEDD > 78 mm

0

70–78 mm

1

< 70 mm

2

LVEF < 19%

0

19–33%

1

> 33%

2

Sensitivity

Specificity

3 points

88.6%

47.4%

4 points

71.4%

67.1%

5 points

42.9%

80.3%

LAD/LVEDD < 0.63

0

0.63–0.68

1

> 0.68

2

(CVP: Central venous pressure; LAD: Left atrial dimension; LVEDD: Left ventricular end-diastolic dimension; LVAD: Left ventricular assist device; RV: Right ventricle; RVEDD: Right ventricular end-diastolic dimension; TAPSE: Tricuspid annular plane systolic excursion).

1236


Table 57.5: Points of Emphasis for the Pre-Left Ventricular Assist Device Echocardiogram

Left Ventricle: Size, geometric shape, systolic function, diastolic function, and filling pressure Left Ventricular Apex: Shape, trabeculae, and thrombus Aortic Valve: Leaflet motion, morphology, severity of valve insufficiency, and presence of stenosis Mitral Valve: Presence of stenosis, motion of leaflets, and severity of valve insufficiency Tricuspid Valve: Annular dimension and severity of valve insufficiency Atrial Septum: Patent foramen ovale and atrial septal defect Pulmonic Valve: Severity of valve insufficiency Inferior Vena Cava: Estimate of central venous pressure Aorta: Ascending aortic size and atherosclerotic plaque Pericardium: Effusion or constrictive changes Right Ventricle: Size, geometric shape, and systolic function

A

B

C

Figs 57.13A to C: Two examples of calculation of tricuspid regurgitation duration. In (A) the duration is quite prolonged, giving a rate corrected value of 631 ms. This puts the patient in a prognostically favorable group; In (B) the rate corrected value is 458 ms, putting the patient in the prognostically less favorable group even though the severity of the valve regurgitation was moderate; (C) and right ventricular systolic pressures were only mildly increased. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

20– 30% reduction in dimensions. These are most effectively performed using direct 2D diameter measurements at the tips of the mitral valve in the parasternal long-axis view (Figs 57.18A and B and Movie clips 57.7 and 57.8). Attempts

should be made to reproduce the same views each time the study is obtained. Measurements of ventricular ejection fraction and function are sometimes difficult to obtain due to the inability to get true long-axis views from the apex.


1237

A

B

C

Figs 57.14A to C: Evaluation of right ventricular function. (A) Tricuspid annular plane systolic excursion (TAPSE) in this case is markedly reduced consistent with a reduced prognosis; (B) Transthoracic measurement of the mid-right ventricle (RV) and mid-left ventricle (LV) diameter, this example the ratio is 0.41, a favorable prognostic finding; (C) Evaluation of fractional area change of the RV in the apical four-chamber view. The end diastolic and end systolic areas are shown. The fractional area change is only 11%, an unfavorable prognostic finding.

Fig. 57.15: Immediate postoperative transesophageal echo. The left ventricular assist device (LVAD) has been ramped up to 8,800 rpm but the left ventricle has become suctioned down to a small volume. In systole, the inflow cannula is now obstructed causing flow acceleration at the inflow site that aliases the display. As soon as systole concludes, inflow abruptly slows to normal.

Since loading conditions are no longer natural, evaluation of an ejection fraction may not have the same meaning in an LVAD patient. While imaging the ventricle, it is also important to obtain views of the inlet cannula at the apex. This should be visible over 90% of the time and may be imaged from low parasternal off-axis views, from distal short-axis views in the parasternal view, and from various apical or off-axis apical views. Cannula position and direction should be shown as best as possible. Color flow Doppler should be utilized in these views and under normal circumstances should show laminar relatively low velocity flow. Pulsed wave inflow velocities should be obtained at the origin of the cannula. These velocities should generally be fairly low, gently pulsatile, and average about 1.0–1.5 m/s, and always less than 2.0 m/s (Figs 57.19A and B).32 In most patients, the outflow portion of the cannula attaches to the pump in the abdomen, thorax, or pericardium. The course of a typical cannula can be

1238


A

B

Figs 57.16A and B: (A) Transesophageal echo high esophageal view showing location of the outflow cannula in the ascending aorta with color flow signal. The arrows show aorta landmarks for reference of location; (B) Continuous wave Doppler of outflow showing pulsatile flow preservation. (AV: Aortic valve annular plane; ST: Sinotubular junction).

followed using off-axis modified parasternal and right parasternal views. The relative position in the chest of outflow cannulas is shown in Figures 57.1 and 57.2. The transthoracic view on the cannula anastomosis is shown in Figure 57.20A with a typical color flow signal in Figure 57.20B and pulsed Doppler in Figure 57.20C. Off axis images from the suprasternal notch or right parasternal imaging positions are usually needed to see the outflow cannula and anastomotic site. The right ventricle should be assessed for size and function. This should be done from standard views and apical views that emphasize the right ventricle. The septal contour should be assessed. Generally most favorable is a relatively neutral position between the two ventricles. This indicates adequate but not excessive unloading (Figs 57.21A to C and Movie clips 57.9 and 57.10). Similarly, the septum can be assessed in the parasternal short-axis views as one sweeps from base to apex. Under normal circumstances, the contour of the curvature should remain reasonably normal. The atrial chambers should be evaluated as with normal studies and the volume of the left atrium measured. It is expected that left atrial volume will diminish over time. The junction of the inferior vena cava and the right atrium should also be evaluated and central venous pressure estimated. Hepatic vein Doppler signals can also be assessed throughout a continuous respiratory cycle. Valvular performance should be evaluated. The mitral valve is expected, with appropriate unloading, to show a reduction in regurgitation. With reduction in left ventricular size, motion of the leaflets might also

improve some, lessening the severity of papillary muscle dysfunction. The tricuspid valve is less predictable. The severity of insufficiency may or may not change depending on changes in size and function of the right ventricle. In some situations, the tricuspid valve will have been repaired, and so the repair should be evaluated for both stenosis and insufficiency. Of considerable importance is the aortic valve. Motion of the aortic valve should be carefully evaluated from multiple views to determine if the valve is opening or not, and if it is opening, if it is opening every beat, intermittently, or partially on each beat. Changes in aortic valve morphology should also be assessed by careful evaluation of the short-axis view. Color Doppler examination is also important for determining if aortic insufficiency has developed.33,34 Motion of the aortic valve will help determine whether speed settings of the device are optimal. At higher rotational speeds, the LVAD takes over relatively greater amounts of output, and in many circumstances the valve no longer opens. As speeds are reduced or as the left ventricle starts improving, some native contribution to outflow is again observed (Figs 57.22A to D and Movie clips 57.11 and 57.12). Diastolic performance of the ventricle can also be assessed by standard indices of tissue Doppler, and mitral valve flow and pulmonary venous inflow. In general, successful unloading of the left ventricle results in a reduction in left-sided filling pressures, but there is no evidence that any intrinsic improvement in diastolic function occurs (Figs 57.23A and B).35 Doppler assessment


Fig. 57.17: Specialized views obtained to help visualize structures in the patient with a left ventricular assist device (LVAD). Source: Reproduced with permission from Elsevier.

1239

1240


A

B

Figs 57.18A and B: Example of pre- and post-left ventricular assist device (LVAD) dimensions taken at 3 months following LVAD placement. There has been significant decompression of the left ventricle (LV), with a 25% decline in LV end diastolic dimension.

A

B

Figs 57.19A and B: (A) Example of off-axis apical view showing the inflow cannula having relatively low inflow velocity (B).

of LV filling shows these changes. On the right side of the heart, the typical response is a reduction in pulmonary artery pressures and also central venous pressures. Right ventricular function does not show significant improvement over time in most patients. Table 57.6 shows some selective data from a single center study demonstrating some of the typical serial changes expected after placement of an axial flow device.

COMPLICATIONS OF LEFT VENTRICULAR ASSIST DEVICES Evidence of Left Ventricular Over-Filling Normally, the LVAD is expected to decompress the left ventricle, reduce its size, and maintain the changes

over time. In some cases, there is evidence of recurrent enlargement of the ventricular chamber. This can be detected qualitatively or more precisely quantitatively by noting dimension changes in the left ventricle. If the ventricle dilates again, the septum may deviate more rightward as filling pressures increase on the left side. Reduced cardiac output may be associated with evidence of stasis, causing visible spontaneous contrast in both the left ventricle and left atrium. Mitral regurgitation may increase in severity if the mitral valve apparatus is stretched and the annulus increases in size. In most settings, there is evidence of over-filling associated with a relative reduction in cardiac output moving through the assist pump and a relative increase in stroke volume across the aortic valve. This typically is manifested by an increase in amplitude and frequency of aortic valve opening from none, minimal,


1241

A

B

C

Figs 57.20A to C: Transthoracic echo example of the right parasternal view of the outflow cannula as it joins the central aorta. (A) Note relative size of cannula; In (B), typical color flow signal of flow in same location; In (C) pulsed Doppler at the outflow is shown with normal velocities. (Ao: Aorta).

A

B

Figs 57.21A and B

1242

C


Figs 57.21A to C: (A) Apical four-chamber view showing a normal septal contour with mild residual right ventricular dysfunction. In (B) and (C) the patient has right ventricular dysfunction causing an abnormal septal contour in the parasternal long- and shortaxis views. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

B

C

D

Figs 57.22A to D: (A) Example by M-mode of intermittent opening of the aortic valve (AV); (B) Typical central jet that can develop after left ventricular assist device (LVAD) placement; (C) M-mode with color of same patient as (B) shows continuous nature of insufficiency flow; (D) Continuous wave (CW) Doppler from the apical view in the same patient. Note that even though the left ventricle (LV) contracts, it does not generate enough force to open the valve.


A

1243

B

Figs 57.23A and B: (A) Mitral flow prior to placement of left ventricular assist device (LVAD) when the patient was in class IIIb heart failure; In (B) the LVAD has been in place for 2 months. Note the improvement in deceleration even though the E/A ratio remains elevated. Table 57.6: Early Serial Changes in Ventricular Size and Function after Placement of a Left Ventricular Assist Device

Pre-Op

Three Months

Six Months

LVEDD (mm)

70

61

60

LVESD (mm)

62

54

54

Biplane LVEF (%)

17

18

16

RVEDD (mm)

35

34

34

RV Function

1.5

1.6

1.4

CVP (mm Hg)

12

9

9

RVSP (mm Hg)

46

26

27

*

Mitral E/A Ratio

2.5

1.6

1.5

Mitral DT (ms)

146

200

195

E/e’ Ratio

13.3

11.8

11.4

Diastolic Grade*

2.5

2.0

2.1

LA Volume (mL)

95

73

65

*For both RV function and severity of diastolic dysfunction, the score was: 0 = normal, 1 = mildly abnormal, 2 = moderately abnormal, 3 = severely abnormal. (CVP: Central venous pressure; DT: Deceleration time; EDD: End-diastolic dimension; EF: Ejection fraction; ESD: End-systolic dimension; LA: Left atrium; LV: Left ventricle; RV: Right ventricle; SP: Systolic pressure). Source: Adapted from reference 28.

or intermittent to present on every beat. There also may be evidence of direct pump failure, which sometimes is nonobstructive. Forward flow velocity is reduced and LVAD regurgitation may occur (Figs 57.24A and B, Movie clip 57.13). In some patients, the increase in flow velocity may only occur at certain times in the cardiac cycle (Figs 57.25A and B). If there is obstruction of the inflow cannula, there may be a change in flow velocity, from the normal laminar, relatively low velocity flow to an increase in velocity that is turbulent. The cannula inflow area should be interrogated with color, continuous wave, and

pulsed wave Doppler. It is also possible that the over-filling and reduced flow is due to an abnormality of the outflow from the pump; thus, the outflow cannula should also be very carefully analyzed for evidence of turbulence or change in velocity from one part of the cannula to another (Figs 57.26A to C and Movie clip 57.14). Specific potential causes of over-filling are categorized in Table 57.7. One specific difference must be noted for the case of high afterload due to hypertension. In this case, the aortic valve stays closed due to increased central aortic pressure.

1244


A

B

Figs 57.24A and B: Patient who suffered sudden power failure of his left ventricular assist device (LVAD). (A) There was a significant change in the aortic valve M-mode that began fully opening in each beat; (B) The flow signal at the inflow cannula showed evidence of weak forward flow, upper arrow, and regurgitant flow (lower arrow). The device did not clot in the 6 hours before surgery. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

A

B

Figs 57.25A and B: This patient had normal inflow cannula velocity (A). Two months later, there is a change in the inflow pattern consistent with obstruction. In this case, velocity peaks near end-systole (B). Peak velocity has increased from about 40 cm/s to almost 200 cm/s.

A Figs 57.26A and B

B


1245

Figs 57.26A to C: This patient showed evidence of reduced output. The inflow cannula appeared normal by three-dimensional imaging with low inflow velocity (A). The aortic valve began to open fully on each beat (B) as shown by the arrows compared to previous intermittent opening (Fig. 57.22D). An increase of flow velocity was seen in the outflow cannula (C) where a kink in the cannula developed. The location of the kink was similar to that seen in Figure 57.1D close to the anastomosis with the aorta.

C

Table 57.7: Causes of Left Ventricular Overfilling

Clinical Signs of Heart Failure Possible echocardiographic changes

Increased LVEDD Septal contour shift rightward Spontaneous contrast in LV, LA Increase in mitral regurgitation Change in mitral inflow signal, E/e’ suggesting increased filling pressure Increased opening of aortic valve to every beat Atrial septal contour shifted rightward

Cause Pump readout changes

Specific echocardiographic findings

Inflow obstruction

Pump failure pump thrombus

Outflow obstruction or high afterload

Reduced flow

Reduced flow

Low pump flow

Increased power consumption

Increased power consumption

Normal power consumption or

Spikes in power

Sudden flow reduction

High afterload: Increased pulsatile index

Apical thrombus

Reduced inflow velocity

Thrombus in outflow cannula

Apical vegetation

Regurgitation signal from flow reversal

Kink in outflow cannula

Adverse change in septum contour

Doppler with different velocities at different part of cannula

Increased inflow velocity

Anatomic obstruction of cannula at aorta

Increased inflow turbulence

High afterload: High velocity pulsatile LVAD flow

(LA: Left atrium; LV: Left ventricle; LVAD: Left ventricular assist device; LVEDD: Left ventricular end-diastolic dimension).

1246


Outflow through the cannula becomes more pulsatile with higher outflow velocity.

A second major abnormality is that of under-filling. Under-filling may be associated with low flow but normal overall power usage of the LVAD device. This could result from an excessive reduction in preload. This may be a consequence of an excessive speed setting of the device and can be associated with “set-down,” in which the device is intermittently obstructed at its inflow cannula site by changes in contour of the interventricular septum or apex (Figs 57.27A to C and Movie clip 57.15). The device is typically programmed to reduce rpms to a default rate until the obstruction is relieved. A second cause of this situation

is right ventricular failure. If the right ventricle deteriorates after the LVAD is placed, septal contour may push from right to left, indicating overload of the right ventricle, reduced systolic performance of the right ventricle, and thus a reduced cardiac output (Fig. 57.28). This situation can be further complicated by worsening of tricuspid valve insufficiency, which will further reduce forward flow out of the right side of the heart and reduce volume delivered to the left ventricle. In some situations, a third possibility exists: right ventricular function may be preserved, but the patient is excessively volume depleted. This could be due to bleeding, poor intake, or excessive diuretic use. There will be a decline in overall cardiac output due to an excessive reduction in right ventricular preload (Table 57.8). Restoration of normal fluid status brings outputs back to baseline.

A

B

C

Figs 57.27A to C: The left ventricle (LV) cavity is small and the gap between the cannula and septum satisfactory in systole (A) but very small toward end-diastole (B). The inflow signal shows increased flow velocity at end-diastole corresponding to the findings (C). Diuretics were stopped and the left ventricular assist device (LVAD) speed reduced to 8,800 rpm. Inflow velocity normalized.

EVIDENCE OF UNDERFILLING OF THE LEFT VENTRICLE


1247

Table 57.8: Causes of Left Ventricular Underfilling

Possible echocardiographic changes

Further reduction in LV end diastolic dimension Leftward septal shift Change in mitral inflow suggesting reduced LV filling and filling pressures Aortic valve continuously closed Atrial septum position variable

Potential causes

Excessive LVAD speed setting Right ventricular failure Increased tricuspid valve insufficiency Dehydration (bleeding, excessive diuresis, poor intake, etc.)

Pump readouts

Reduced output Normal power usage Occasional “set down” episodes due to inflow cannula obstruction

Specific possible echocardiographic findings Low cannula inflow velocity Change in septal contour to left or evidence of septal obstruction of inflow Worsening RV function and high central venous pressure Dehydration with reduced RV size, inferior vena caval signs of low or normal central venous pressure (LV: Left ventricle; LVAD: Left ventricular assist device; RV: Right ventricle).

Fig. 57.28: Example of right ventricle (RV) failure which causes the septum to deviate to the left. (LV: Left ventricle).

High Left Ventricular Assist Device Flow with Low Net Forward Cardiac Output In most circumstances, this is associated with an abnormality of the aortic valve, most frequently the

development of aortic insufficiency. With the position of the pump circuit routing blood from LV to central aorta, the presence of aortic insufficiency causes a direct loss of forward cardiac output. Aortic insufficiency and changes in the aortic valve have been evaluated in several serial studies. The phenomenon of deterioration of aortic valve leaflets, changes in coaptation, reduction in excursion of the leaflets, and the development of continuous aortic insufficiency have all been documented in multiple series.32,34,36,37 Morphological changes on the valve have been demonstrated. Changes in the valve may be related to lack of opening motion. Some groups now suggest that the aortic valve should be carefully observed at the time of setup of pump speed, with pump speed adjusted to allow at least intermittent or modest opening motion of the valve. This may prevent deterioration of the valve leaflets over time. More serial information is necessary to determine more definitively the etiology and the most appropriate settings. Aortic insufficiency is best evaluated in the parasternal long-axis view. It may be continuous depending on the status of LV ejection of blood (see Figs 57.22 A to D and Movie clip 57.12).

1248


Pericardial abnormalities may occasionally occur. Development of a significant pericardial effusion, and particularly cardiac tamponade physiology, may substantially change the loading conditions. The exact effect on the heart is determined by the actual location of the effusion (loculated or not). Hemopericardium can complicate the early post-LVAD recovery period. Normal diagnostic criteria for cardiac tamponade are not reliable, particularly Doppler criteria. Chamber collapse is the best indicator of tamponade.24,31

OPTIMIZING LEFT VENTRICULAR ASSIST DEVICE SETTINGS The goal of device optimization is to (1) preserve cardiac output as much as possible, (2) eliminate congestion, and (3) help the patient feel as well as possible. The LVAD devices display certain pieces of information on the controller system. For example, the HeartMate II displays revolutions per minute (rpm; range 6,000–15,000 rpm, most commonly 8,000–10,000 rpm), power consumption in watts, flow, and the pulsatile index. The device is capable of directly measuring rpms and power consumption. It calculates flow and the pulsatility index based on the other two pieces of data. The device calculations give reasonable estimates of flow; however, at extremes of the rpm range, for instance below 8,000, calculated flow rates become less reliable. Flow is also determined by the pressure gradient across the device. As speeds go up, left ventricular systolic pressure will fall within the left ventricular chamber relative to the central aortic pressure. A comprehensive echocardiogram is necessary to obtain full information in order to optimize speed settings. In some circumstances, an interactive echocardiogram may be performed using a ramp protocol to follow the effect of serial pump adjustments on the echocardiogram. From the echocardiogram, particular attention should be made to obtain full information on the following:38–40 • Cannula flow velocities: Flow velocities should be examined carefully at both the inflow site and the outflow site. Flow velocities that are not elevated or unusually shaped or turbulent indicate normal flow. One should maneuver the transducer to optimize obtaining flow in the most parallel position possible. This will usually be from some type of an off-axis low parasternal or apical view. • Ventricular septal contour position: The interventricular septum should be carefully evaluated. Use

•

•

•

of a respirometer may enhance the information by allowing motion of the septum to be tracked with the respiratory cycle. Under ideal circumstances, the septum should stay at the midline. Turning device rpms up too high may result in the septum drifting leftward and actually collapsing the left ventricle. This may also be observed in ramp protocols when one is trying to quickly adjust the device to achieve an optimal speed. On the other hand, device settings that are too slow, that reduce flow out of the left ventricle, may result in the septum drifting rightward to the right ventricle. This can result in a reduced efficiency of right ventricular performance and reduced output. Atrial septum: Position of this structure indicates a relative difference between LA and RA pressure. One group40 has suggested that estimation of RA pressure using the inferior vena cava dimension and its response to respiration can be used to estimate LV unloading. They assign LA pressure = RA pressure if the atrial septum is midline, LA pressure = RA pressure – 5 mm Hg if the septum is deviated to the left, and LA pressure = RA pressure + 5 mm Hg if the atrial septum is deviated to the right. If RA pressure is 15 mm Hg or greater and LA pressure is equal to or greater than RA pressure, these authors would suggest increasing pump speed to further unload the LV. Evaluation of LV filling characteristics may be done directly by evaluation of the grade of diastolic filling and estimation of filling pressures. Successful unloading should cause a reduction in diastolic grade, E/e' ratio, and left atrial volume.35 The early mitral deceleration time can be measured and should prolong as unloading occurs. The deceleration time can be indexed by dividing deceleration time by peak E velocity (e.g., 150 ms/50 cm/s = 3 ms/cm/s). A value < 2 is associated with adverse outcomes and is another indicator that suggests an increase in pump speed may be beneficial (see Figs 57.23A and B). The aortic valve should be carefully observed. There has been much controversy about the optimal settings with regard to aortic valve motion. It has been well documented by multiple studies that the aortic valve can deteriorate over time. Valve thickening occurs, some fusion of leaflets may occur in certain circumstances, and valvular insufficiency can develop (see Figs 57.22A to D). It now appears that the best policy is to set the speed so that there is intermittent opening of the aortic valve. This has the salutary effect


of allowing a slight increase in pulsatility that could be beneficial for the patient and also, more importantly from the valve standpoint, it may reduce the likelihood of fusion abnormalities, thickening, or development of aortic insufficiency over time. It is no longer recommended to set the speed so that the aortic valve stays closed. Proof of long-term benefit of this policy is not yet available. • Mitral valve performance: Optimal unloading of the left ventricle should result in a reduction of mitral valve insufficiency if it was present before placement of the LVAD. In most settings, mitral valve insufficiency is not due to primary valve disease; rather, it is due to secondary valve disease from papillary muscle dysfunction, annular enlargement, and reduced excursion of the leaflet apparatus. In many patients, as ventricular size is reduced, the severity of mitral valve insufficiency may diminish. Ideally, the severity of mitral insufficiency should be reduced to mild or nothing with unloading. • Arterial pressure: An ideal setting would be a mean pressure > 65 mm Hg. • Right ventricle: Optimal settings of the LVAD should result in a reduction of filling pressures on the left side of the heart that should be translated backward to the right side. Optimization of the LVAD should result in a reduction of right ventricular pressures over time. Similarly, central venous pressure should come down over time, particularly if there is fluid optimization that occurs. A goal would be to lower RA pressure to 5–10 mm Hg through a combination of pump settings and medical management.38 • Cardiac output: Total cardiac output is best estimated using pulsed Doppler flow at the right ventricular outflow tract just above the pulmonic valve. Views should be obtained to allow accurate measurement of the diameter of the region. The flow velocity integral is used in the formula: RV outflow diameter/2 × π × RV outflow TVI = stroke volume Stroke volume can be multiplied by heart rate to obtain a cardiac output. An indexed value of 2.2 L/min/m2 or greater is a reasonable goal for total outputs. A formalized ramp test protocol for the HeartMate II has been developed by Uriel et al.38 This protocol serially evaluates device indices such as pulsatile index, power output, and flow calculations from the device, along with blood pressure and heart rate. The device is changed through a range of 8,000–12,000 rpm, if the patient

1249

tolerates this, in increments of 400 rpm. From an echocardiographic standpoint, ventricular dimensions are serially measured, the septal contour is observed, and aortic valve opening and severity of aortic insufficiency are observed, as are mitral insufficiency and right ventricular systolic pressure estimates. From these measurements the authors have been able to show characteristic changes in their protocol, particularly when related to simultaneous plotting of the pulsatility index, left ventricular enddiastolic dimension, and power output of the device. Protocols of this nature can be used to optimize settings by observing all the variables discussed above, and in certain circumstances may also be used to evaluate for the possibility of thrombosis in and around the device because the characteristics of the ramp protocol change when thrombus is present. A summary of optimization goals and measurements is shown in Table 57.9.

EXPLANTATION A small group of patients show recovery of function sufficient to allow consideration for explantation.6 A few disease processes are inherently self limited and have an optimistic outlook for recovery. However, in cases of true dilated cardiomyopathy, the chance of recovery is very low. For instance, in one series of 1,108 patients, 20 (1.8%) had the HeartMate II explanted due to recovery of left ventricular function. This trial and others have also suggested that a nonischemic etiology is more likely to recover. Of the 1,108 patients cited above, 531 were nonischemic; they had a recovery rate of 3.4%. A group of 578 of the patients were ischemic; they had a recovery rate of only 0.3%. Age also appears to be a significant factor. Patients < 40 years of age have a higher rate of recovery, and patients who have a shorter duration of heart failure symptoms tend to have a higher rate of recovery.41,42 These general findings have also been consistently found in trials evaluating medical management of dilated cardiomyopathy. Echocardiography plays a central role in identifying patients who may be considered for explantation. Weaning protocols were more easily performed with pulsatile pumps since they could be temporarily slowed down to a very low rate while patients were carefully monitored. The transition to continuous flow devices has made weaning more difficult. Some devices can be shut down temporarily; others can only be partially slowed down. Specific weaning protocols are beyond the scope of this chapter and tend to be institution-specific.43 It should be

1250


Table 57.9: Optimization of Left Ventricular Assist Device Performance: Echocardiographic Measurements Indicating a Favorable Response

Cardiac Index: Cardiac Index > 2.2 L/m2/min Ventricular Septum: Neutral at midline Atrial Septum: Neutral at midline with an estimated right atrial pressure at 5–10 mm Hg Mitral Flow Deceleration Slope Index: greater than 2 ms/cm/s Left Atrial Volume: Reduced compared to baseline Left Ventricular End-Diastolic Dimension: Reduced by 20–30% compared to baseline Aortic Valve Motion: Intermittent partial opening Mitral Valve Regurgitation: Reduced compared to baseline Tricuspid Valve Regurgitation: Reduced compared to baseline Right Ventricle Size and Function: Stable or improved compared to baseline

noted that dobutamine stress testing has been tried in a limited number of patients. Positive findings of enhanced inotropic responsiveness combined with evidence of improved cardiac output were shown to be valuable predictors of explantation success in one study. A more recent report from Dandel et al.44 suggested the following echocardiographic parameters be considered, and if met, the patient might be considered for weaning. • The left ventricle should have an end-diastolic diameter < 55 mm and an ejection fraction ≥ 45%. • The right ventricle should not be dilated. • Valvular insufficiency of all four valves should be either not present or only mild. These factors are combined with right heart catheterization parameters. Recommended is a cardiac index > 2.6 L/min/m2, a pulmonary capillary wedge pressure < 13 mm Hg, and a right atrial pressure < 10 mm Hg. If patients achieve this level of improvement of performance and, importantly, show evidence of stable maintenance of these changes over time, then patients might be considered for a weaning protocol.

PERCUTANEOUS CONTINUOUS FLOW DEVICES Impella Device This device is devised for short-term implantation. The device is inserted generally through a large femoral artery and retrogradely brought into position across the aortic valve so that the distal portion of the device suctions blood out of the left ventricle, across the valve, and deposits the blood in the ascending aorta (Fig. 57.3). Since this is a retrograde percutaneous device, several different considerations before placement of the

device should be considered when reviewing either a transthoracic or transesophageal echocardiogram. Prior to implantation, besides the usual information obtained in a comprehensive echocardiogram, one should pay particular attention to the presence of large atheromas in the ascending aorta, size of the ascending aorta, abnormalities of the aortic valve, particularly in regard to significant stenosis that might restrict leaflet motion, increasing the difficulty of placing the device across the valve, or substantial aortic regurgitation, which might make the device of little or no value. The left ventricular outflow tract should be evaluated for possible unusual shape or narrowing, and the mitral valve should be evaluated for baseline insufficiency and any unusual chordal abnormalities. During or immediately following positioning of the device, appropriate location of the device across the aortic valve can be assessed echocardiographically by noting the location of the device relative to the valve and also using color Doppler to verify inflow comes from the left ventricle and outflow goes to the aorta (Figs 57.29A to C).45 Transesophageal echocardiography can be particularly valuable in assessing the location and function of the device.46 For example, failure of the device to improve patient status could be related to malposition of the device. One case report recently described distal positioning of the device with entrapment in the papillary muscles, inhibiting outflow into the aorta. A 3D transesophageal echo (TEE) was demonstrated to be of particular value in assessing the position of the device.47

TandemHeart The TandemHeart (see Fig. 57.4) typically utilizes a femoral vein and femoral artery with an external pump.10 These devices are frequently placed using


1251

A

B

C

Figs 57.29A to C: (A) Parasternal long-axis view showing the position of the Impella device (arrow); (B) Typical artifact generated by the device; (C) M-mode of the device and aortic valve leaflets.

A

B

Figs 57.30A and B

1252


Figs 57.30A to C: Subcostal view confirming cannula position in the inferior vena cava (IVC), arrow, (A). Apical four-chamber view confirming correct location of the cannula tip (arrow); (B). In some cases the cannula may migrate; in this case (C) the tip moved into LV (arrow). (LA: Left atrium; RA: Right atrium; L: Liver).

C echocardiographic imaging support, commonly transesophageal echocardiography. Preprocedure TEE screening is of considerable value to evaluate not only issues of ventricular and valvular function but also to carefully evaluate the left and right atrial chambers for any unusual anatomical abnormalities or thrombi that would complicate placement of the large-bore catheter moved retrograde up through the vena cava and then trans-septally across the atrial septum. TEE is frequently used for guidance of the trans-septal puncture, and once the device is placed for correct positioning of the retrograde catheter in the left atrium. Color Doppler can assist in detecting flow since the device has multiple holes at the end of its inflow catheter (see Figs 57.4A and B). As with other assist devices, echocardiography can serially evaluate the effect of the device. Also, if the device appears to be working improperly, echocardiographic imaging, particularly to evaluate the position of the inflow cannula, may be of great value (Figs 57.30A to C and Movie clips 57.16 to 57.17, 57.18). In some circumstances, this cannula could migrate either further inward or backward across the atrial septum and become malpositioned. These catheters also can form clots and sometimes become obstructed, which echocardiography can identify.

REFERENCES 1. Liotta D, Crawford ES, Cooley DA, et al. Prolonged partial left ventricular bypass by means of an intrathoracic pump implanted in the left chest. Trans Am Soc Artif Intern Organs. 1962;8:90–9. 2. DeBakey ME. Left ventricular bypass pump for cardiac assistance. Clinical experience. Am J Cardiol. 1971;27(1): 3–11. 3. Rose EA, Gelijns AC, Moskowitz AJ, et al.; Randomized Evaluation of Mechanical Assistance for the Treatment of

4.

5.

6.

7.

8.

9. 10.

11.

12.

Congestive Heart Failure (REMATCH) Study Group. Longterm use of a left ventricular assist device for end-stage heart failure. N Engl J Med. 2001;345(20):1435–43. Nose Y, Motomra T, Miyamoto H. History of Mechanical Circulatory Support. In: Joyce DL, Joyce LD, Loebe M, editors. Mechanical Circulatory Support. New York, NY: McGraw Hill Medical; 2012:3–12. Interagency Registry for Mechanically Assisted Circulatory Support. Quarterly Statistical Report 2012, 3rd Quarter. Available from www.intermacs.org. 2012; Accessed January 2013. Mancini DM, Beniaminovitz A, Levin H, et al. Low incidence of myocardial recovery after left ventricular assist device implantation in patients with chronic heart failure. Circulation. 1998;98(22):2383–9. Bruckner BA, Stetson SJ, Farmer JA, et al. The implications for cardiac recovery of left ventricular assist device support on myocardial collagen content. Am J Surg. 2000; 180(6):498–501; discussion 501. Bruckner BA, Stetson SJ, Perez-Verdia A, et al. Regression of fibrosis and hypertrophy in failing myocardium following mechanical circulatory support. J Heart Lung Transplant. 2001;20(4):457–64. Abiomed, product description. Available at www.abiomed. com. 2013; Accessed January 2013. Burkhoff D, Cohen H, Brunckhorst C, et al. A randomized multicenter clinical study to evaluate the safety and efficacy of the TandemHeart percutaneous ventricular assist device versus conventional therapy with intraaortic balloon pumping for treatment of cardiogenic shock. Am Heart J. 2006;152(3):469.e1–469.e8. Marks J, Macedo M, Dasse K. Levitronix CentriMag and PediVAS Systems: Applications and clinical results. In: Joyce D, Joyce L, Loebe M, editors. Mechanical Circulatory Support: Principles and Applications. New York, NY: McGraw Hill Medical; 2012:160–5. Nishinaka T, Miller PJ, Bearnson GB, et al. EVAHEART left ventricular assist system. In: Joyce D, Joyce L, Loebe M, editors. Mechanical Circulatory Support: Principles and Applications. New York, NY: McGraw Hill Medical; 2012: 238–41.


13. Mookadam F, Kendall CB, Wong RK, et al. Left ventricular assist devices: physiologic assessment using echocardiography for management and optimization. Ultrasound Med Biol. 2012;38(2):335–45. 14. Stout M, Ravindran R, Miller C, et al. Preimplant transthoracic echocardiographic assessment of continuous flow left ventricular assist device. Echocardiography. 2012; 29(1):52–8. 15. Piacentino V 3rd, Ganapathi AM, Stafford-Smith M, et al. Utility of concomitant tricuspid valve procedures for patients undergoing implantation of a continuous-flow left ventricular device. J Thorac Cardiovasc Surg. 2012; 144(5):1217–21. 16. Piacentino V 3rd, Williams ML, Depp T, et al. Impact of tricuspid valve regurgitation in patients treated with implantable left ventricular assist devices. Ann Thorac Surg. 2011;91(5):1342–6; discussion 1346. 17. Kukucka M, Stepanenko A, Potapov E, et al. Impact of tricuspid valve annulus dilation on mid-term survival after implantation of a left ventricular assist device. J Heart Lung Transplant. 2012;31(9):967–71. 18. Slaughter MS, Rogers JG, Milano CA, et al. HeartMate II Investigators. Advanced heart failure treated with continuous-flow left ventricular assist device. N Engl J Med. 2009;361(23):2241–51. 19. Kormos RL, Teuteberg JJ, Pagani FD, et al. HeartMate II Clinical Investigators. Right ventricular failure in patients with the HeartMate II continuous-flow left ventricular assist device: incidence, risk factors, and effect on outcomes. J Thorac Cardiovasc Surg. 2010;139(5):1316–24. 20. El Atrache M, Brewer R, Hassan N, et al. Tricuspid Repair at the Time of LVAD Implantation is Associated with Improved Survival. J Am Coll Cardiol 2012;59(13):E881. 21. Maltais S, Topilsky Y, Tchantchaleishvili V, et al. Surgical treatment of tricuspid valve insufficiency promotes early reverse remodeling in patients with axial-flow left ventricular assist devices. J Thorac Cardiovasc Surg. 2012; 143(6):1370–6. 22. Topilsky Y, Oh JK, Shah DK, et al. Echocardiographic predictors of adverse outcomes after continuous left ventricular assist device implantation. JACC Cardiovasc Imaging. 2011;4(3):211–22. 23. Fitzpatrick JR 3rd, Frederick JR, Hsu VM, et al. Risk score derived from pre-operative data analysis predicts the need for biventricular mechanical circulatory support. J Heart Lung Transplant. 2008;27(12):1286–92. 24. Scalia GM, McCarthy PM, Savage RM, et al. Clinical utility of echocardiography in the management of implantable ventricular assist devices. J Am Soc Echocardiogr. 2000; 13(8):754–63. 25. Puwanant S, Hamilton KK, Klodell CT, et al. Tricuspid annular motion as a predictor of severe right ventricular failure after left ventricular assist device implantation. J Heart Lung Transplant. 2008;27(10):1102–7. 26. Kukucka M, Stepanenko A, Potapov E, et al. Right-to-left ventricular end-diastolic diameter ratio and prediction of right ventricular failure with continuous-flow left ventricular assist devices. J Heart Lung Transplant. 2011;30(1):64–9.

1253

27. Ochiai Y, McCarthy PM, Smedira NG, et al. Predictors of severe right ventricular failure after implantable left ventricular assist device insertion: analysis of 245 patients. Circulation. 2002;106(12 Suppl 1):I198–I202. 28. Kato TS, Farr M, Schulze PC, et al. Usefulness of twodimensional echocardiographic parameters of the left side of the heart to predict right ventricular failure after left ventricular assist device implantation. Am J Cardiol. 2012;109(2):246–51. 29. Catena E, Tasca G. Role of echocardiography in the perioperative management of mechanical circulatory assistance. Best Pract Res Clin Anaesthesiol. 2012;26(2):199–216. 30. Liao KK, Miller L, Toher C, et al. Timing of transesophageal echocardiography in diagnosing patent foramen ovale in patients supported with left ventricular assist device. Ann Thorac Surg. 2003;75(5):1624–6. 31. Rasalingam R, Johnson SN, Bilhorn KR, et al. Transthoracic echocardiographic assessment of continuous-flow left ventricular assist devices. J Am Soc Echocardiogr. 2011; 24(2):135–48. 32. Estep JD, Stainback RF, Little SH, et al. The role of echocardiography and other imaging modalities in patients with left ventricular assist devices. JACC Cardiovasc Imaging. 2010;3(10):1049–64. 33. Soleimani B, Haouzi A, Manoskey A, et al. Development of aortic insufficiency in patients supported with continuous flow left ventricular assist devices. ASAIO J. 2012;58(4): 326–9. 34. Cowger J, Pagani FD, Haft JW, et al. The development of aortic insufficiency in left ventricular assist device-supported patients. Circ Heart Fail. 2010;3(6):668–74. 35. Chapman CB, Allana S, Sweitzer NK, et al. Effects of the HeartMate II Left Ventricular Assist Device as Observed by Serial Echocardiography. Echocardiography. 1-11-2013. 36. Toda K, Fujita T, Domae K, et al. Late aortic insufficiency related to poor prognosis during left ventricular assist device support. Ann Thorac Surg. 2011;92(3):929–34. 37. Pak SW, Uriel N, Takayama H, et al. Prevalence of de novo aortic insufficiency during long-term support with left ventricular assist devices. J Heart Lung Transplant. 2010; 29(10):1172–6. 38. Uriel N, Morrison KA, Garan AR, et al. Development of a novel echocardiography ramp test for speed optimization and diagnosis of device thrombosis in continuous-flow left ventricular assist devices: the Columbia ramp study. J Am Coll Cardiol. 2012;60(18):1764–75. 39. Topilsky Y, Maltais S, Oh JK, et al. Focused review on transthoracic echocardiographic assessment of patients with continuous axial left ventricular assist devices. Cardiol Res Pract. 2011;2011:187434. 40. Topilsky Y, Hasin T, Oh JK, et al. Echocardiographic variables after left ventricular assist device implantation associated with adverse outcome. Circ Cardiovasc Imaging. 2011;4(6):648–61. 41. Goldstein DJ, Maybaum S, MacGillivray TE, et al.; HeartMate II Clinical Investigators. Young patients with nonischemic cardiomyopathy have higher likelihood of left ventricular recovery during left ventricular assist device support. J Card Fail. 2012;18(5):392–5.

1254


42. Mano A, Nakatani T, Oda N, et al. Which factors predict the recovery of natural heart function after insertion of a left ventricular assist system? J Heart Lung Transplant. 2008;27(8):869–74. 43. Osaki S, Sweitzer NK, Rahko PS, et al. To explant or not to explant: an invasive and noninvasive monitoring protocol to determine the need of continued ventricular assist device support. Congest Heart Fail. 2009;15(2):58–62. 44. Dandel M, Weng Y, Siniawski H, et al. Pre-explant stability of unloading-promoted cardiac improvement predicts outcome after weaning from ventricular assist devices. Circulation. 2012;126(11 Suppl 1):S9–19.

45. Catena E, Milazzo F, Merli M, et al. Echocardiographic evaluation of patients receiving a new left ventricular assist device: the Impella recover 100. Eur J Echocardiogr. 2004;5(6):430–7. 46. Patel KM, Sherwani SS, Baudo AM, et al. Echo rounds: the use of transesophageal echocardiography for confirmation of appropriate Impella 5.0 device placement. Anesth Analg. 2012;114(1):82–5. 47. Abusaid GH, Ahmad M. Transthoracic real time threedimensional echocardiography in Impella placement. Echocardiography. 2012;29(4):E105–E106.

CHAPTER 58 Echocardiographic Assessment of Left Atrial Function Utpal N Sagar, Hirohiko Motoki, Allan L Klein

Snapshot ¾¾ Anatomy ¾¾ Physiology

INTRODUCTION As the role of echocardiography has evolved to assess hemodynamic status and diastolic function in addition to characterizing two-dimensional structure and function, there has been an emphasis on improving echocardi ographic assessment of the left atrium (LA). This has become of increasing importance as left atrial volume and function have been described as strong predictors of major adverse cardiovascular events. In this chapter, we will review the structure and multifaceted function of the LA, the physiology of the LA, modalities of functional assessment, and review left atrial function in the context of various cardiovascular disease states.

ANATOMY The LA is the most posteriorly situated chamber of the heart and is oriented superiorly and to the left of the right atrium. The pulmonary veins normally drain into the posterior aspect of the LA. These vessels are covered by the visceral or inner layer of pericardium. The serous layer is fused with the outer fibrous pericardium.1 The LA may be divided into different regions, including the left atrial appendage which is small, tubular,

¾¾ Functional Assessment ¾¾ Left Atrial Pathophysiology

and is varied in the number of lobes which comprise its structure. The wall of the appendage also has variable thickness, with alternating muscle bundles. The vestibule of the LA includes the region around the mitral valve orifice and is noted for its generally smooth endocardial surface. Encompassing the posteroinferior wall of the LA is the mitral isthmus, which extends between the entrance of the left inferior pulmonary vein and the mitral valve. Proximally, the vestibule merges with the septal component, which joins with the posterior wall and the roof of the LA. The fossa ovalis, which is a remnant of the embryonic septum primum, may be seen from the left atrial aspect of the septum as a crescent-shaped edge. The posterior portion of the LA into which the pulmonary veins drain is referred to as the venous component. There are small ridge-like structures between the entrance of the superior and inferior pulmonary veins, and a larger ridge between the left atrial appendage and the entrance to the left atrial appendage.1 The walls of the LA that border the regions of the LA described previously are not of uniform thicknesses. Most notably, the wall surrounding the venous portion of the LA is composed of varying amounts of musculature with differing orientations.1

1256


Fig. 58.2: Graphical representation of the pressure–volume relationship of left atrial (LA) function. Note the dynamic changes in the pressure and volume that occur during the cardiac cycle. (MVC: Mitral valve closure; MVO: Mitral valve opening; Pre-A: Pre-atrial contraction).

Fig. 58.1: Left atrial (LA) phasic functions and their relationship with the cardiac cycle. (TMF: Transmitral flow; PVF: Pulmonary vein flow, ECG: Electrocardiogram). Note the changes in left atrial volumes through the various phases of left atrial function.

PHYSIOLOGY Although the role of the LA could be simply described as a chamber that receives oxygenated blood, its function is far more complex. Below, we will discuss the phasic function of the LA and the factors that affect its function.

Phasic Left Atrial Function Broadly, there are three phases of left atrial function, including the reservoir, conduit, and contraction phases (Fig. 58.1). The LA first acts as a reservoir during left ventricular systole as the mitral valve annulus is displaced apically, augmenting LA volume with a concomitant

decrease in pressure. The LA then receives blood that returns via the pulmonary veins. The difference between the passive LA emptying volume and the pulmonary blood flow is the reservoir volume. The next phase of left atrial function is the conduit phase in which the LA conducts blood into the left ventricle with the opening of the mitral valve and occurs until left atrial contraction. Essentially, the mitral valve annulus descends toward the cardiac base, decreasing LA volume. This volume may be determined by the difference in LV stroke volume and the sum of the active and passive LA volumes. In the final phase, the left atrial pectinate muscles contract in late diastole with an increase in LA pressure, and development of a pressure gradient between the LA and LV, resulting in blood flow across the mitral valve. This so-called “atrial kick” has a significant contribution to the stroke volume of the left ventricle and may be defined as the difference in the left atrial volume at the onset of the P-wave and minimal LA volume.2 Figure 58.2 graphically demonstrates this relationship of left atrial pressure and volume throughout the cardiac cycle, and its relation to left ventricular filling. The LA also functions as a volume and pressure sensor of diastolic function. And, through the release of natriuretic peptides and interactions with the sympathetic nervous system, as well as the renin–angiotensin–aldosterone system, it communicates with various neurohormonal systems.3

Chapter 58: Echocardiographic Assessment of Left Atrial Function

Physiological Effects on Left Atrial Function It follows that the previously described left atrial function do not occur in isolation and are related to left ventricular compliance. Abnormalities in left ventricular, valvular, or atrial disease are often reflected as an increase in left atrial filling pressures, which may be observed as enlargement of left atrial size.4 Hence, LA afterload increases as left ventricular (LV) filling pressures increase and as LV diastolic dysfunction worsens. This increase in LA afterload and LA volume results initially in an increase in LA size and an improvement in LA function. However, LA contractility declines once a threshold has been reached, similar to the Frank–Starling curve of the LV.2 Various examples of the relationship between LA and LV size, and functional assessment will be discussed in the left atrial pathophysiology section of this chapter.

FUNCTIONAL ASSESSMENT We have already described the significant interplay between LA and LV function, such that events during each phase of “LA phasic function” are affected by factors from both the LA and LV. However, despite considerable investigation, the magnitude and relative importance of the atrial contribution to LV filling and cardiac output remain controversial, and provide a motivation for a more complete evaluation of the atrial cycle. Recent advances in catheter ablation for the treat ment of atrial fibrillation (AF), in dual- and threechamber pacemakers that maintain atrioventricular and biventricular synchrony, and in the pathological and clinical relevance of chamber-specific structural, elec trical, and ionic remodeling have increased the interest in accurately imaging the LA structure and function. With respect to the assessment of the LA function, twodimensional echocardiography (2DE), three-dimensional echocardiography (3DE), Doppler echocardiography, and speckle tracking echocardiography have distinctly different strength and weaknesses, and are complementary in specific clinical scenarios. In this section, we discuss the role of each modality to assess LA function with an emphasis on the relative merits of newer imaging techniques and how these may be applied in the various clinical settings.

Volume Left atrial size has been compared to the hemoglobin A1c in diabetes as a measure of the average effect of LV filling

1257

pressures over time,5,6 making it a useful marker of both the chronicity and severity of LV diastolic dysfunction.7,8 Left ventricle size measurement is routinely perfor med by transthoracic echocardiography (Figs 58.3A to E). LA antero posterior dimension can be measured by M-mode or B-mode in the parasternal long-axis view. This method is convenient and has been widely adopted in routine clinical practice. However, LA volume measured by either the ellipsoid model or the Simpson’s method is a more reliable measure of true LA size than M-mode LA dimension9 and is the recommended method for the accurate assessment of LA size.10 Measuring the maxi mum LA volume at the time of mitral valve opening is now routinely performed with echocardiography, although it only represents a snapshot of LA function at a specific point of the cardiac cycle. Maximal LA volume index is a predictor of adverse cardiovascular outcomes such as AF, stroke, and congestive heart failure and/or death in various conditions, including community-based populations,11–14 postmyocardial infarction,15,16 heart failure,17–19 hypertrophic cardiomyopathy,20–22 AF,23 and postcardiac surgery patients.24 However, measurement of LA phasic volumes using 2DE is time consuming, and errors can arise from geometric assumptions of biplane volume calculations, as well as from difficulties with echocardiographic window and the timing of various atrial events. To improve the accuracy of LA size measurement, 3DE has been studied (Fig. 58.4). The 3DE measurements demonstrate favorable test–retest variability25 and good agreement with cardiac magnetic resonance imaging.25–27 Among the newer techniques including 3DE, cardiac computed tomography, and cardiac magnetic resonance imaging, 3DE shows the most promise of adoption in routine clinical practice as it is noninvasive, readily available, and can be added onto the routinely performed 2DE examination. 3DE also offers the possibility of meas uring LA volumes at different phases of the cardiac cycle, yielding information on LA phasic function.

Spectral Doppler Pulmonary vein flow, transmitral flow, and mitral annular velocity are routinely measured. These parameters are determined by LA function, as well as LV systolic and diastolic performance. Peak velocity of mitral A-wave indicates LA mechanical function, although it is also affected by heart rate and loading conditions.28 Peak mitral A velocity has been shown to be associated with

1258


A

C

B

D

E

Figs 58.3A to E: Various methods of echocardiographic determination of left atrial size. Figure A demonstrates M-mode through the left atrium (LA), Figures B and C demonstrate volume measurements of the LA using the biplane method of discs (modified Simpson’s rule) from apical four-chamber and two-chamber views, respectively. Figures D and E demonstrate the measurement of LA volume from area–length method using the images from apical four-chamber and two-chamber views.

Fig. 58.4: Multiplanar imaging of the left atrium, with three-dimensional rendering and determination of the left atrial volume.

AF recurrence postcardioversion.29 Atrial ejection force, calculated from the mitral annulus area and mitral A-wave velocity, has been suggested to be a useful

atrial mechanical function30 and has been shown to be prognostic for cardiovascular events in a population with a high prevalence of hypertension and diabetes,31 although the method is limited by the robustness and variability of the measurements. Mitral annular velocity during atrial contraction (a') is another indicator of atrial contractile function, measured by tissue Doppler imaging (TDI) of the mitral annulus to quantify the low-velocity, high-amplitude myocardial velocities. Its amplitude is related to both atrial contractility and LV end-diastolic pressure.32 Increased a' is also seen in those with LV hypertrophy, indicating increased LA active ejection force.33 Decreased a' has been shown to be a predictor for elevated pulmonary pressures in mitral regurgitation, clinical deterioration in aortic stenosis, AF postcoronary artery bypass grafting, and progression from paroxysmal to persistent nonvalvular AF. In heart failure,


1259

of AF, left ventricular systolic dysfunction, and clinical heart failure, the role of LA functional assessment and its pathophysiological applications has continued to evolve. In this section, we will discuss the role of left atrial functional assessment in various clinical settings.

Hypertension

Fig. 58.5: An example of speckle tracking, used here to determine left atrial strain and strain rate.

low a' is associated with poor exercise tolerance and is a better predictor of cardiac events than E/e' and decele ration time of transmitral E-wave.

Speckle Tracking Measures of myocardial deformation have been increasingly adapted to study LA mechanics. Both echo cardiographic methods of measuring strain and SR, 2D speckle tracking imaging, and color TDI have been adapted to measuring LA deformation. Speckle tracking calculates strain by tracking tissue deformation via characteristic myocardial speckles frame-by-frame, with SR given by the rate of such deformation (Fig. 58.5). Color TDI generates a spatial map of myocardial velocities, from which SR of the region of interest is derived, with strain calculated by integrating the SR data. The advantage of analyzing LA mechanics with strain and SR imaging is the information that can be obtained about each component of LA phasic function. One could use this method to resolve the exact change in LA phasic function with different disease states and investigate the effect after treatment. Thus, deformation-based parameters of LA reservoir function could provide the prognostic information in the population at risk for adverse cardiovascular events.

LEFT ATRIAL PATHOPHYSIOLOGY While left atrial size has been shown to have a significant prognostic role in the prediction of the development

The left ventricular hypertrophy and LA dilation that is observed in patients with moderate and severe hypertension often is not observed in patients with mild hypertension. Earlier in this chapter, we noted that strain and strain rate (SR) imaging may be useful in characterizing the components of LA phasic function. In the setting of mild hypertension, SR imaging may show a reduction in the early diastolic LA SR, which is associated with a decrease in LA conduit volume. These changes may reflect early LV diastolic dysfunction, which may herald the development of LV hypertrophy and LA dilation, and possibly AF and clinical symptoms.34

Atrial Fibrillation Impairments in LA structure and function may commonly lead to AF. Various echocardiographic modalities have been studied to evaluate the degree of LA fibrosis that has been associated with AF. Atrial conduction time as measured by TDI has been shown to predict the development of AF in the general population when prolonged greater than 190 ms.35 Recently, percutaneous catheter ablation has been used more frequently to successfully manage symptomatic and medically refractory AF. In these patients, the best predictors for maintenance of sinus rhythm following ablation were parameters of LA reservoir function, determined by SR imaging.36,37 Studies have shown that LA reservoir function has been related to LA structural remodeling and fibrosis of the atrial wall.38,39 Following conversion to sinus rhythm, LA volume and function may be monitored, with those patients who have greater degrees of dysfunction being selected for further therapy, such as antiarrhythmics.40 Direct current cardioversion is a widely used treatment modality for both emergent and elective manage ment of AF. However, there is significant risk of stroke and thromboembolism associated with direct current cardioversion.41–44 Classically, this was thought to be due to pre-existing left atrial thrombus or continuous or prominent spontaneous echo contrast. Earlier, we described the location and anatomy of the left atrial appendage. Transesophageal echocardiography (TEE) is

1260


the best method of detection of thrombi in the left atrial appendage and LA that could be embolized in the setting of cardioversion (Figs 58.6A to C). However, significant work in this area has described myocardial stunning that follows cardioversion, giving rise to conditions in the LA that may lead to thrombus, even if no LA thrombus was present prior to cardioversion.45 Nevertheless, TEE prior to cardioversion has become standard of care, and has been studied extensively.45,46 Techniques have evolved now to involve the functional assessment of the left atrial appendage, evaluating emptying velocities with pulsed wave Doppler at the entrance of the appendage. Peak LA appendage emptying velocity has been shown to be a predictor of maintenance of sinus rhythm following

A

cardioversion.47,48 TEE-guided cardioversion may be impo rtant with the use of the new oral anticoagulants such as dabigatran, rivaroxaban, and apixaban since there is no anticoagulation monitoring in patients with AF.

Cardiomyopathies Assessment of LA function may help to diagnose, to differentiate, and to guide therapy of various cardio myopathies. For example, patients with hypertrophic cardiomyopathy have been shown to have decreased LA longitudinal function in addition to decreased LA reservoir function. This may be used to differentiate hypertrophic cardiomyopathy from other forms of left ventricular hypertrophy.49,50 Figures 58.7A to E show an

B

C

Figs 58.6A to C: The spectrum of left atrial appendage pathology. Figure A shows the presence of left atrial spontaneous echocontrast, or “smoke”; Figure B demonstrates prominent, persistent spontaneous echocontrast in the left atrium and left atrial appendage (LAA), consistent with “sludge”; Figure C shows the presence of a minimally mobile echodensity within the left atrial appendage, consistent with thrombus (arrow).

A

B

D

C

E

Figs 58.7A to E: Patient with hypertrophic obstructive cardiomyopathy (HOCM), as seen in Figure A. Figures B and C demonstrate severe left atrial enlargement. Mitral inflow shows decreased A-wave (Figure D) and tissue Doppler image (Figure E) shows moderate to severe decreased atrial contraction with decreased a' velocity. (LA: Left atrium; LV: Left ventricle).


A

B

C

D

1261

Figs 58.8A to D: Echocardiogram of a patient with cardiac amyloidosis. The apical four-chamber view in Figure A demonstrates the degree of left atrial enlargement; Figure B shows the degree of increased left ventricular wall thickness and the characteristic echotexture of a patient with cardiac amyloidosis. The transmitral flow demonstrating restrictive diastolic pattern with small A-wave is seen in Figure C. Tissue Doppler in Figure D shows severely depressed a' velocity, consistent with restrictive cardiomyopathy. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

echo-Doppler evaluation of LA function in a patient with HOCM. Also, in patients with cardiac amyloidosis, we see that the LA is severely dilated and a' is reduced, conferring a high risk for thromboembolism. Figures 58.8A to D show an echo-Doppler evaluation of LA function in cardiac amyloidosis. In a study of a population of patients with ischemic and idiopathic cardiomyopathy, LA reservoir function predicted a positive response to cardiac resynchronization therapy, although the study did not report strain and SR for the other phases of LA function.51

REFERENCES 1. Ho SY, Cabrera JA, Sanchez-Quintana D. Left atrial anatomy revisited. Circ Arrhythm Electrophysiol. 2012;5:220–8.

2. Blume GG, McLeod CJ, Barnes ME, et al. Left atrial function: physiology, assessment, and clinical implications. Eur J Echocardiogr. 2011;12:421–30. 3. To AC, Flamm SD, Marwick TH, et al. Clinical utility of multimodality LA imaging: assessment of size, function, and structure. JACC Cardiovasc Imaging. 2011;4:788–98. 4. Leung DY, Boyd A, Ng AA, et al. Echocardi ographic evaluation of left atrial size and function: current under standing, pathophysiologic correlates, and prognostic implications. Am Heart J. 2008;156:1056–64. 5. Abbas AE, Fortuin FD, Schiller NB, et al. A simple method for noninvasive estimation of pulmonary vascular resis tance. J Am Coll Cardiol. 2003;41:1021–7. 6. Douglas PS. The left atrium: a biomarker of chronic diastolic dysfunction and cardiovascular disease risk. J Am Coll Cardiol. 2003;42:1206–7.

1262


7. Osranek M, Seward JB, Buschenreithner B, et al. Diastolic function assessment in clinical practice: the value of 2-dimensional echocardiography. Am Heart J. 2007; 154: 130–6. 8. Tsang TS, Barnes ME, Gersh BJ, et al. Left atrial volume as a morphophysiologic expression of left ventricular diastolic dysfunction and relation to cardiovascular risk burden. Am J Cardiol. 2002;90:1284–9. 9. Abhayaratna WP, Seward JB, Appleton CP, et al. Left atrial size: physiologic determinants and clinical applications. J Am Coll Cardiol. 2006;47:2357–63. 10. Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18:1440–63. 11. Tsang TS, Gersh BJ, Appleton CP, et al. Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women. J Am Coll Cardiol. 2002;40:1636–44. 12. Tsang TS, Barnes ME, Gersh BJ, et al. Prediction of risk for first age-related cardiovascular events in an elderly population: the incremental value of echocardiography. J Am Coll Cardiol. 2003;42:1199–205. 13. Tsang TS, Abhayaratna WP, Barnes ME, et al. Prediction of cardiovascular outcomes with left atrial size: is volume superior to area or diameter? J Am Coll Cardiol. 2006; 47:1018–23. 14. Takemoto Y, Barnes ME, Seward JB, et al. Usefulness of left atrial volume in predicting first congestive heart failure in patients > or = 65 years of age with well-preserved left ventricular systolic function. Am J Cardiol. 2005;96:832–6. 15. Moller JE, Hillis GS, Oh JK, et al. Left atrial volume: a powerful predictor of survival after acute myocardial infarction. Circulation. 2003;107:2207–12. 16. Beinart R, Boyko V, Schwammenthal E, et al. Long-term prognostic significance of left atrial volume in acute myocardial infarction. J Am Coll Cardiol. 2004;44:327–34. 17. Rossi A, Cicoira M, Zanolla L, et al. Determinants and prognostic value of left atrial volume in patients with dilated cardiomyopathy. J Am Coll Cardiol. 2002;40:1425. 18. Tsang TS, Barnes ME, Gersh BJ, et al. Risks for atrial fibrillation and congestive heart failure in patients >/=65 years of age with abnormal left ventricular diastolic relaxation. Am J Cardiol. 2004;93:54–8. 19. Sabharwal N, Cemin R, Rajan K, et al. Usefulness of left atrial volume as a predictor of mortality in patients with ischemic cardiomyopathy. Am J Cardiol. 2004;94:760–3. 20. Tani T, Tanabe K, Ono M, et al. Left atrial volume and the risk of paroxysmal atrial fibrillation in patients with hypertrophic cardiomyopathy. J Am Soc Echocardiogr. 2004;17:644–8. 21. Losi MA, Betocchi S, Aversa M, et al. Determinants of atrial fibrillation development in patients with hypertrophic cardiomyopathy. Am J Cardiol. 2004;94:895–900.

22. Losi MA, Betocchi S, Barbati G, et al. Prognostic significance of left atrial volume dilatation in patients with hypertrophic cardiomyopathy. J Am Soc Echocardiogr. 2009;22:76–81. 23. Osranek M, Bursi F, Bailey KR, et al. Left atrial volume predicts cardiovascular events in patients originally diag nosed with lone atrial fibrillation: three-decade follow-up. Eur Heart J. 2005;26:2556–61. 24. Osranek M, Fatema K, Qaddoura F, et al. Left atrial volume predicts the risk of atrial fibrillation after cardiac surgery: a prospective study. J Am Coll Cardiol. 2006;48:779–86. 25. Jenkins C, Bricknell K, Marwick TH. Use of real-time three-dimensional echocardiography to measure left atrial volume: comparison with other echocardiographic techni ques. J Am Soc Echocardiogr. 2005;18:991–7. 26. Keller AM, Gopal AS, King DL. Left and right atrial volume by freehand three-dimensional echocardiography: in vivo validation using magnetic resonance imaging. Eur J Echocardiogr. 2000;1:55–65. 27. Artang R, Migrino RQ, Harmann L, et al. Left atrial volume measurement with automated border detection by 3-dimensional echocardiography: comparison with Magnetic Resonance Imaging. Cardiovasc Ultrasound. 2009;7:16. 28. Choong CY, Herrmann HC, Weyman AE, et al. Preload dependence of Doppler-derived indexes of left ventricular diastolic function in humans. J Am Coll Cardiol. 1987;10: 800–8. 29. Spiecker M, Bohm S, Borgel J, et al. Doppler echocar diographic prediction of recurrent atrial fibrillation following cardioversion. Int J Cardiol. 2006;113:161–6. 30. Manning WJ, Silverman DI, Katz SE, et al. Atrial ejection force: a noninvasive assessment of atrial systolic function. J Am Coll Cardiol. 1993;22:221–5. 31. Chinali M, de Simone G, Roman MJ, et al. Left atrial systolic force and cardiovascular outcome. The Strong Heart Study. Am J Hypertens. 2005;18:1570–6; discussion 7. 32. Nagueh SF, Sun H, Kopelen HA, et al. Hemodynamic determinants of the mitral annulus diastolic velocities by tissue Doppler. J Am Coll Cardiol. 2001;37:278–85. 33. Khankirawatana B, Khankirawatana S, Peterson B, et al. Peak atrial systolic mitral annular velocity by Doppler tissue reliably predicts left atrial systolic function. J Am Soc Echocardiogr. 2004;17:353–60. 34. Eshoo S, Boyd AC, Ross DL, et al. Strain rate evaluation of phasic atrial function in hypertension. Heart. 2009;95: 1184–91. 35. De Vos CB, Weijs B, Crijns HJ, et al. Atrial tissue Doppler imaging for prediction of new-onset atrial fibrillation. Heart. 2009;95:835–40. 36. Schneider C, Malisius R, Krause K, et al. Strain rate imaging for functional quantification of the left atrium: atrial deformation predicts the maintenance of sinus rhythm after catheter ablation of atrial fibrillation. Eur Heart J. 2008;29:1397–409. 37. Di Salvo G, Caso P, Lo Piccolo R, et al. Atrial myocardial deformation properties predict maintenance of sinus rhythm after external cardioversion of recent-onset lone atrial fibrillation: a color Doppler myocardial imaging


38.

39.

40.

41. 42.

43.

44.

and transthoracic and transesophageal echocardiographic study. Circulation. 2005;112:387–95. Kuppahally SS, Akoum N, Burgon NS, et al. Left atrial strain and strain rate in patients with paroxysmal and persistent atrial fibrillation: relationship to left atrial structural remodeling detected by delayed-enhancement MRI. Circ Cardiovasc Imaging. 2010;3:231–9. Cameli M, Lisi M, Righini FM, et al. Usefulness of Atrial Deformation Analysis to Predict Left Atrial Fibrosis and Endocardial Thickness in Patients Undergoing Mitral Valve Operations for Severe Mitral Regurgitation Secondary to Mitral Valve Prolapse. Am J Cardiol. 2012. Rosca M, Lancellotti P, Popescu BA, et al. Left atrial fun ction: pathophysiology, echocardiographic assessment, and clinical applications. Heart. 2011;97:1982–9. Lown B. Electrical reversion of cardiac arrhythmias. Br Heart J. 1967;29:469–89. Bjerkelund CJ, Orning OM. The efficacy of anticoagulant therapy in preventing embolism related to D.C. electrical conversion of atrial fibrillation. Am J Cardiol. 1969;23: 208–16. Stein B, Halperin JL, Fuster V. Should patients with atrial fibrillation be anticoagulated prior to and chronically following cardioversion? Cardiovasc Clin. 1990;21:231–47; discussion 48–9. Grimm RA, Stewart WJ, Black IW, et al. Should all patients undergo transesophageal echocardiography before elect rical cardioversion of atrial fibrillation? J Am College Car diol. 1994;23:533–41.

1263

45. Grimm RA. Transesophageal echocardiography-guided cardioversion of atrial fibrillation. Echocardiography. 2000; 17:383–92. 46. Klein AL, Grimm RA, Murray RD, et al. Use of transes ophageal echocardiography to guide cardioversion in patients with atrial fibrillation. New Engl J Med. 2001; 344:1411–20. 47. Antonielli E, Pizzuti A, Palinkas A, et al. Clinical value of left atrial appendage flow for prediction of long-term sinus rhythm maintenance in patients with nonvalvular atrial fibrillation. J Amer College Cardiol. 2002;39:1443–9. 48. Omran H, Jung W, Schimpf R, et al. Echocardiographic parameters for predicting maintenance of sinus rhythm after internal atrial defibrillation. J Amer College Cardiol. 1998;81:1446–9. 49. Paraskevaidis IA, Panou F, Papadopoulos C, et al. Evaluation of left atrial longitudinal function in patients with hypertrophic cardiomyopathy: a tissue Doppler imaging and two-dimensional strain study. Heart. 2009;95:483–9. 50. Rosca M, Popescu BA, Beladan CC, et al. Left atrial dysfunction as a correlate of heart failure symptoms in hypertrophic cardiomyopathy. J Am Soc Echocardiogr. 2010;23:1090–8. 51. D’Andrea A, Caso P, Romano S, et al. Different effects of cardiac resynchronization therapy on left atrial function in patients with either idiopathic or ischaemic dilated cardiomyopathy: a two-dimensional speckle strain study. Eur Heart J. 2007;28:2738–48.

CHAPTER 59 The Use of Echocardiography to Assess Cardiac Hemodynamics and Guide Therapy Roy Beigel, Robert J Siegel

Snapshot  Right Atrial Pressure/Central Venous Pressure

 AddiƟonal Parameters for EsƟmaƟon of

 Pulmonary Artery Hemodynamics

LeŌ Atrial Pressure  Stroke Volume, Stroke Distance, Cardiac Output and Systemic Pulmonary Shunts (QP/QS)

 LeŌ-Sided Filling Pressures

INTRODUCTION Accurate noninvasive hemodynamic assessment has the potential to greatly improve patient management with regard to volume status, pharmacological treatment, and clinical outcomes. Several studies have shown that the “time-honored physical examination” has very limited sensitivity and specificity for right atrial pressure (RAP), pulmonary artery pressure (PAP), as well as left atrial (LA) filling pressures. Since the 1970s, the standard for hemodynamic assessment has been invasive measurements made by pulmonary artery (PA) catheterization. However, use of the PA catheter has been subject to criticism1–3 as it can increase patient morbidity.4,5 Doppler-echocardiographic measurements of right- and left-sided filling pressures, pulmonary vascular resistance (PVR), and cardiac output (CO) are possible to obtain in most patients. Echocardiography can potentially provide adequate alternative hemodynamic data, which are more accurate than the physical examination without the risks of invasive monitoring.

RIGHT ATRIAL PRESSURE/CENTRAL VENOUS PRESSURE Central venous pressure (CVP; Table 59.1) and RAP are the same, provided that there is no obstruction of the vena cava. Traditionally, RAP is measured with a central venous catheter (normal range is between 1 and 7 mm Hg for mean RAP). Elevated values have adverse prognostic implications for morbidity and mortality,6–9 making the accurate assessment of RAP an important factor in patients’ assessment, management and outcome.10,11 Accurate evaluation of RAP is also a necessary for the noninvasive estimation of the systolic and diastolic PAP (DPAP). Table 59.1 lists various methods used for the echocardiographic evaluation of RAP.

Inferior Vena Cava Parameters (Fig. 59.1) The most commonly utilized method uses the inferior vena cava (IVC) size and its respiratory variation for

Chapter 59: The Use of Echocardiography to Assess Cardiac Hemodynamics and Guide Therapy

1265

Table 59.1: The Various Methods Utilized for the Echocardiographic Evaluation of Right Atrial Pressure (RAP)

Method

Criteria Used

Strength and Limitations

IVC parameters—2D or M-mode subcostal imaging of the IVC (Fig. 59.1)

IVC diameter, collapse: • < 2.1 cm, > 50%—normal RAP ~ 3 • > 2.1 cm, > 50%—intermediate* RAP ~ 8 • > 2.1 cm, < 50%—High RAP ~> 15 *In cases which the IVC diameter and collapse do not fit the normal or high criteria.

Most validated method Above a certain elevation of RAP, the IVC may be fully dilated and not collapsing, making estimation above this point difficult Increased IVC diameter and/or decreased collapse in the presence of RAP can be seen with: • Low respiratory compliance • Mechanically ventilated patients • Trained athletes • Prominent Eustachian valve • Narrowing of the IVC–RA junction • Web or tissue present in the IVC

Systemic and hepatic venous flow— Doppler flow in the vena cava, jugular, or hepatic veins (Figs 59.2A and B)

Vs > Vd—normal RAP Vs < Vd—elevated RAP (> 8 mm Hg)

Obtaining flow velocity curves from the SVC is simple, less obtainable with hepatic veins Severe tricuspid regurgitation can alter the venous flow pattern without correlation to RAP Atrial compliance and relaxation and tricuspid annular descent can affect flow patterns and make them less reliable Atrial fibrillation or past cardiac surgery can cause the hepatic vein systolic flow to be diminished regardless of RAP

Hepatic vein filling fraction (HVFF)—pulsed Doppler of hepatic veins

VsVTI/(VsVTI + VdVTI) < 55—High RAP > 8 mm Hg

Validated in mechanically ventilated patients Single study24 Atrial fibrillation or past cardiac surgery can cause the hepatic vein systolic flow to be diminished regardless of RAP

Doppler and TDI—pulsed Doppler E/e′ > 6—RAP > 10 mm Hg of the tricuspid inflow and TDI of the tricuspid valve (Figs 59. 3A and B)

Validated in mechanically ventilated patients May not be an accurate method in patients who have undergone cardiac surgery

Right ventricular regional isovolumic relaxation time (RV rIVRT)—tricuspid TDI

> 59 ms correlates to RAP > 8 mm Hg

Studied on a limited number of patients (n = 21) in a single study25

3D RA dimensions—3D transthoracic imaging of the RA

3DE maximal RA volume ≥ 35 mL/m2 combined with IVC diameter ≥ 2 cm—correlates with RAP > 10 mm Hg

Single study in a selective group of heart failure patients with EF < 35%27

(3DE: Three-dimensional echocardiography; IVC: Inferior vena cava; RA: Right atrial; SVC: Superior vena cava; TDI: Tissue Doppler imaging; VTI: Velocity time integral).

the echocardiographic evaluation of RAP. As the IVC is a highly compliant vessel, its size and flow dynamics vary with changes in CVP and volume. As shown in Figure 59.1, during inspiration (which produces negative intrathoracic pressure), vena cava pressure decreases and flow increases.12,13 At low or normal RAP, there is systolic predominance in IVC flow, such that the systolic flow is greater than the diastolic flow. As RAP increases, it is transmitted to the IVC, resulting in blunting of the forward

systolic flow, reduced IVC collapse with inspiration and eventually IVC dilatation (Fig. 59.1). Current guidelines14,15 recommend using the IVC maximal diameter (IVC max) 1–2 cm from the RA–IVC junction at end-expiration and the IVC collapsibility index (IVCCI, which equals [IVCmax – IVCmin]/IVCmax). For RAP assessment, as noted in Table 59.2, an IVC with a diameter < 2.1 cm and collapse > 50% correlates with a normal RAP of 0 to 5 mm Hg. An IVC < 2.1 cm with < 50% collapse and an IVC > 2.1 cm with

1266


Fig. 59.1: Imaging of the inferior vena cava (IVC, marked with asterisk) using 2D echocardiography (top, and middle images), and M-mode echocardiography (bottom images) from the subcostal view. The left three images show respiratory variations of the IVC in a patient with normal right atrial pressure (RAP). The right three images show no respiratory variation of the IVC, which is also dilated. This patient was found to have an elevated RAP.

> 50% collapse correspond to an intermediate RAP of 5 to 10 mm Hg. An IVC > 2.1 cm with <50% collapse suggests a high RAP of 15 mm Hg. Using midrange values of 3 mm Hg for normal and 8 mm Hg for intermediate RAP is recommended. However, if there is minimal collapse of the IVC (<35%) and/or secondary indices of elevated RAP are present, upgrading to the higher pressure limit (i.e. 5 and 10 mm Hg in case of normal and intermediate RAP, respectively) should be done. Patients should be supine during assessment of the IVC as other positions may lead to either under- or overestimation of IVC diameter and/ or collapsibility.16 Patients with low compliance with deep inspiration may have a diminished IVC collapse. A “sniff ” maneuver that causes a sudden decrease in intrathoracic pressure and by that accentuating the normal inspiratory response can be used to differentiate those with normal IVC collapsibility from those with a diminished IVC collapsibility. IVC size and collapsibility are helpful to identify RAP as being high or low, but this method does not provide precise numeric values for RAP. It should be noted that the IVC can be dilated in individuals with a normal RAP. Common causes of a dilated IVC in the setting of normal RAP17,18 are listed in Table 59.1. In order to overcome some of the limitations of RAP estimation through IVC indices, additional Dopplerechocardiographic parameters have been evaluated and proposed to better quantify RAP (Table 59.1).

Table 59.2: The Various Methods Utilized for the Echocardiographic Evaluation of Pulmonary Artery Pressure (PAP)

Method Criteria Used Systolic Pulmonary Artery Pressure (SPAP): Using the TR jet—Simplified ΔP = 4 × V2 + RAP = SPAP Bernoulli equation (Fig. 59.5)

Pulmonary flow acceleration time (Fig. 59.6)

Lesser range of 100 ms indicates elevated SPAP

Strength and Limitations Widely validated Simple equation Underestimation can occur if: • RAP underestimated • Misalignment of Doppler signal • Poor TR signal • Severe TR Overestimation can occur if: • RAP overestimated • Mistakenly using the tricuspid valve closing spike • Not widely studied • Validated only in patients with chronic heart failure • Measurements can be affected by extremes of heart rate (below 60 or above 100 beats per minute) Contd....


1267

Contd.... Method Criteria Used Diastolic Pulmonary Artery Pressure (DPAP): Using the pulmonary ΔP = 4 × V2 + RAP = DPAP regurgitation (PR) jet—Simplified Bernoulli equation (Fig. 59.9)

TR velocity at time of pulmonic valve opening—Simplified Bernoulli equation

ΔP = 4 × V2 + RAP = DPAP

Mean Pulmonary Artery Pressure (MPAP): Using the peak pulmonary ΔP = 4 × V2 + RAP = MPAP regurgitation (PR) jet—Simplified Bernoulli equation (Fig. 59.9)

Tracing the TR jet (Fig. 59.10) Empirical formulas

PVR: Formula using surrogates for the transpulmonary pressure gradient and transpulmonary flow

Formulas using the pre-ejection period (PEP), AcT, and total systolic time (TT) Estimation of the PVR index (PVRI)

MPAP = 0.61 SPAP + 2 mm Hg MPAP = DPAP + 1/3 (SPAP-DPAP)

PVR (WU) = 10 × TR velocity/RVOT VTI + 0.16

PVR = –0.156 + 1.154 × [(PEP/AcT)/TT]

PVRI = 1.97 + 190 × [SPAP/(HR × RVOT VTI)] SPAP/(HR × RVOT VTI) >0.076 correlated with severe pulmonary vascular disease with PVRI > 15 WU/m2

Strength and Limitations Simple equation Not widely validated PR jet not always acquirable Underestimation can occur if: • RAP underestimated • Misalignment of Doppler signal • Poor PR signal Overestimation can occur if: • RAP overestimated TR jet more detectable then PR Not widely validated Underestimation can occur if: • RAP underestimated • Misalignment of Doppler signal • Poor PR signal • Severe PR Overestimation can occur if: • RAP overestimated Simple equation Not widely validated PR jet not always acquirable Underestimation can occur if: • RAP underestimated • Misalignment of Doppler signal • Poor PR signal Overestimation can occur if: • RAP overestimated Validated in a single study49 Easy to obtain Validated only invasively51 Validated echocardiographically in a single study43 Not widely validated Same limitations as SPAP and DPAP Not widely validated Underestimation can occur if: • Misalignment of Doppler signal • Poor TR signal • Severe TR • RVOT not well visualized in patients with poor acoustic window Single study of heart failure patients with EF < 35%, in sinus rhythm59 Single study of patients with PH60

(PH: Pulmonary hypertension; PVR: Pulmonary vascular resistance; RAP: Right atrial pressure; RVOT: Right ventricular outflow tract; TR: Tricuspid regurgitation; VTI: Velocity time integral).

1268


Using pulsed wave Doppler, the hepatic vein systolic filling fraction (HVFF), which is the ratio of the velocity time

integrals (VTIs): VsVTI/(VsVTI + VdVTI), can be obtained. A value < 55% was found to be the most sensitive (86%) and specific (90%) sign of an RAP > 8 mm Hg. With higher RAP, there was a decrease in systolic filling fraction.24 In this single study, the best model for prediction of mean RAP was = 21.6 – 24 × HVFF. Although IVC collapsibility cannot be evaluated in mechanically ventilated patients, hepatic vein flow velocities have been validated in this situation,24 provided that the velocities are averaged over ≥5 consecutive beats and comprising ≥1 respiratory cycle.15 The maximal early filling velocity through the tricuspid valve during diastole (E-wave) increases as the RAP rises. The use of tissue Doppler imaging (TDI) allows recording of myocardial and annular velocities, and can measure the velocity of tissue relaxation of the lateral tricuspid annulus in diastole (e'-wave) (Figs 59.3A and B). It has been shown that there is a relationship between RAP and the E/e' ratio: A high E velocity combined with a low e' giving an E/e' ratio of > 6 was found to be predictive of a RAP > 10 mm Hg. This correlation was found to also be accurate in patients on mechanical ventilation. However, this method may not be an accurate in patients who have undergone prior cardiac surgery. The RV regional isovolumic relaxation time (RV rIVRT) is the time period between the end of systolic annular motion and the onset of the e'-wave upon TDI of the lateral tricuspid annulus as evaluated in the apical four-chamber view. Using this index, it was found that an RV rIVRT of < 59 ms corresponds to a RAP > 8 mm Hg.25

A

B

Systemic Venous Flow (Figs 59.2A and B) The central venous Doppler flow pattern seen in the vena cava, jugular, and hepatic veins is characterized as seen by three distinct waveforms.19 The first is the systolic wave (Vs) caused by RA relaxation and descent of the tricuspid ring associated with right ventricular (RV) systole. The second is the diastolic wave (Vd), which occurs during rapid ventricular filling when the tricuspid valve is open. The third is a positive A-wave, which occurs with RA contraction and represents reverse flow. The A-wave is small and might not be present in normal individuals. In the majority of normal adults, inspiration increases the magnitude of Vs and Vd, whereas the A-wave, if present, decreases in amplitude. At low or normal RA pressures, there is systolic predominant venous flow, such that the velocity of Vs is greater than the velocity of Vd (Figs 59.2A and B). With elevation of the RA pressure, the systolic flow predominance is lost, such that Vs is substantially decreased and Vs/Vd is < 1. The higher the RAP the lower the pressure gradient between these veins and the RA causing diminished forward systolic flow. This blunted gradient is present in patients with restrictive heart disease and elevated right-sided filling pressures.20–23

Doppler and Tissue Doppler Imaging (Figs 59.3A and B)

Figs 59.2A and B: Evaluation of the central venous flow pattern using pulsed wave Doppler imaging. (A) Systolic (S) and diastolic (D) flow in the superior vena cava of an adult with a normal biphasic pattern. The S/D > 1 is supportive of normal right atrial pressure (RAP); (B) S and D flow velocity in the hepatic vein in a patient with elevated RAP. There is diminished S, increased D, and an S/D < 1.


A

1269

B

Figs 59.3A and B: Doppler and tissue Doppler imaging (TDI) of the tricuspid valve. (A) Tricuspid inflow velocity Doppler recording (E = 36.1 cm/s); (B) Tricuspid annular velocity, e , is 5.2 cm/s. In this patient, the E/e ratio is >6, which supports that the RAP is >10 mm Hg.

Doppler and TDI provide an alternative for RAP evaluation when subcostal views cannot be obtained and when there is inability to assess the IVC and hepatic indices. They can also be used to corroborate the prediction of RAP using HVFF in patients on mechanical ventilation where IVCCI is inaccurate.26

RA Dimensions (Fig. 59.4) Chronically elevated RAP generally leads to RA enlargement. RA size and volume can be assessed from many twodimensional echocardiographic (2DE) views but it is most commonly measured in the apical four-chamber view15 (Fig. 59.4). Three-dimensional echocardiography (3DE) provides tomographic imaging of cardiac chambers and has the potential to be a more accurate modality for atrial volume quantification than 2DE. In one study,27 3DE RA volume correlated with RAP (r = 0.51, p < 0.001) in heart failure (HF) patients. Conversely, 2DE measurements of the RA (both size and 2DE RA volume) have not been shown to correlate with RAP.24 Compared to the American Society of Echocardiography (ASE) recommendations of using an IVC diameter of ≥ 2 cm and decreased respiratory collapse of <40%, 3DE measured maximal RA volume of ≥35 mL/m2 combined with an IVC diameter ≥ 2 cm improves the sensitivity in identifying RAP > 10 mm Hg.27 Currently, there is no single ideal parameter for noninvasive RAP estimation. Using the 2010 ASE criteria,15 which is based on IVC parameters, RAP can be categorized as low (0–5), normal (6–10), or elevated (11–20). A multiparameter approach from other methods

Fig. 59.4: Measuring right atrial (RA) dimensions. 2D echocardiographic images from the apical view focusing on the right heart. On the left, the measurements of the RA major and minor axis diameters are estimated at 4.87 and 3.07 cm, respectively. On the right, the RA area tracing, which is 13.7 cm2.

available is to yield even more accurate estimation of RAP. It is likely that the combination of measurements using echocardiographic findings that measure dynamic changes, flow, and dimensions will provide the best noninvasive assessment of RAP.

PULMONARY ARTERY HEMODYNAMICS (TABLE 59.2) Pulmonary arterial hemodynamics are important for patient diagnosis management, and prognosis. Current

1270


echo-Doppler modalities allow evaluation and estimation of numerous parameters from the pulmonary vasculature: systolic PAP (SPAP), DPAP, and mean PAP (MPAP) as well as indirect estimation of other parameters such as PVR.

Systolic Pulmonary Artery Pressure The SPAP is equal to the RV systolic pressure in the absence of pulmonary valve stenosis or other RV outflow tract (RVOT) obstruction. The normal value for the SPAP with invasive measurements is between 15 and 30 mm Hg. The SPAP equals the pressure gradient between the PA and the RV plus the RAP. The pressure gradient (ΔP) can be calculated using the Bernoulli equation: ΔP = 4 × V2, where V is the velocity of the tricuspid regurgitation (TR) jet in cm/s (Fig. 59.5). In apparently healthy individuals, the prevalence of TR upon Doppler echocardiography varies within a range of 20 to 94% (depending on the age of the cohort being studied).28–30 Figure 59.6 shows the pulmonary flow acceleration time (PAcT), an alternate, less widely used method for screening patients for the presence of pulmonary hypertension (PH). PAcT is the interval between the onset of the forward flow in the PA to its peak velocity. Values of <100 ms are associated with PH.31,32 While the use of the Bernoulli equation has been widely validated,33,34 it can be imprecise, especially in patients with lung disease.35,36 Table 59.3 lists common causes of inaccuracy using echo-Doppler for determination of PAP. Underestimation

Fig. 59.5: Evaluation of systolic pulmonary artery pressure (SPAP) using Doppler imaging of the tricuspid regurgitation (TR) jet. The maximal velocity (Vmax) is 368 cm/s. Using the Bernoulli equation: P = 4 × V2, a maximal pressure gradient (Max PG) of 54 mm Hg between the right ventricle and atrium is calculated. When added to the right atrial pressure, the SPAP can be estimated.

can be due to variations in Doppler angle of interrogation, underestimation of RAP (especially when it is very elevated; Figs 59.7A and B), the presence of severe TR, or a poor TR signal.15,37 Overestimation of SPAP is less common and often is due to overestimation of RAP; it can also result from overestimating the TR signal peak velocity, as well as mistakenly using the tricuspid valve closing spike due to tricuspid valve closure for the tricuspid maximal velocity. Nonetheless, Doppler estimation of SPAP is used as a standard reliable method for screening patients for suspected PH. A TR velocity of >2.8 m/s (corresponding to a pressure gradient of 31 mm Hg) is regarded as the cutoff velocity to define elevated SPAP. However, in obese38 and elderly39 patients, the “normal” cutoff may be higher. To reduce false-negative results, multiple imaging planes and color Doppler should be used for optimal alignment with the regurgitant jet. In cases with a poor Doppler signal, it can be enhanced with either agitated saline, contrast, or an air–blood–saline mixture40–42 (Fig. 59.8). However, this can also lead to overestimation of the TR velocity due to signal artifacts.

Diastolic Pulmonary Artery Pressure The DPAP is equivalent to the LA and LV end-diastolic pressure (LVEDP) when evaluated in individuals without moderate or severe PH. Normal range is between 6 and 12 mm Hg. In patients with a PVR of >200 dynes/s/cm–5

Fig. 59.6: Evaluation of systolic pulmonary artery pressure (SPAP) using PA acceleration time (PAcT), which is the interval between the onset of the forward flow in the PA to its peak velocity (yellow line). A value < 100 ms is associated with an elevated PAP. In this patient (the same patient in Figure 59.5), the PAcT is 63 ms, consistent with an elevated SPAP.


1271

Table 59.3: Causes for Inaccurate Estimation of Pulmonary Artery Pressure by Echocardiography

Cause

Resolution

Underestimation: Variations in Doppler angle of interrogation

Multiple imaging planes to receive best Doppler signal, use of color Doppler for optimal alignment with the regurgitant jet

Underestimation of right atrial pressure (RAP)

Adequate assessment of RAP using a multiparameter approach

Severe tricuspid regurgitation Poor Doppler signal

Enhance signal with either, agitated saline, contrast, or an air–blood–saline mixture.

Overestimation: Overestimation of RAP

Adequate assessment of RAP using a multiparameter approach

Mistakenly using the tricuspid valve closing spike for the tricuspid maximal velocity

Adequate analysis of the tricuspid Doppler signal

Contrast artifacts

Adequate use of contrast, and adequate analysis of the tricuspid Doppler signal

A

B

Figs 59.7A and B: Underestimation of systolic pulmonary artery pressure (SPAP). In this patient the estimated tricuspid regurgitation (TR) gradient was 42 mm Hg. The estimated right atrial pressure (RAP) using inferior vena cava diameter of 2.78 cm and absence of respiratory collapse (bottom) was 15 mm Hg, giving an estimated SPAP of 57 mm Hg. However, the actual pulmonary artery catheter reading for SPAP was 84 mm Hg. This underestimation was due to underestimation of the RAP, which was measured invasively as 40 mm Hg.

A

B

C

Figs 59.8A to C: Enhancing a poor tricuspid regurgitation (TR) Doppler signal (A) with saline (B) or a saline + blood mixture (C), which gives even more enhanced results.

1272


Fig. 59.9: Evaluation of diastolic and mean pulmonary artery pressure (DPAP and MPAP) using Doppler imaging of the pulmonic regurgitation (PR) jet. The maximal velocity (Vmax) is 281 cm/s (asterisk), and the velocity at end diastole is 195 cm/s (arrow). Using the Bernoulli equation: P = 4 × V2, the maximal pressure gradient of 32 mm Hg between the pulmonary artery (PA) and the right ventricle (RV) during diastole is calculated and corresponds with the MPAP. When added to the right atrial pressure (RAP), this improves accuracy. The gradient at end diastole between the PA and the RV is also calculated and is 15 mm Hg. When added to the RAP, the DPAP is given.

or a MPAP > 40 mm Hg, the DPAP is higher (>5 mm Hg difference) than the mean pulmonary capillary wedge pressure (PCWP).43 As demonstrated in Figure 59.9, Doppler echocardiography can be used to estimate DPAP15 by using the simplified Bernoulli equation with the velocity of the pulmonic regurgitation (PR) jet at end diastole providing the end-diastolic PA–RV gradient. The pulmonary artery diastolic pressure (PADP) can be estimated by adding the end-diastolic PA–RV to the RAP.44 This measurement correlates well with invasive measurements. The most common errors in DPAP estimation have been attributed to inaccurate estimation of RAP.45 However, the PR jet is not always detected (even with the use of saline). The pulmonic valve opens when the RV and PA pressures transiently equalize.46 The gradient between the RA and RV can be measured using the TR velocity and the velocity at time of pulmonary vein (PV) opening combined with the RAP, allowing an estimate of the DPAP47 (with the use of superimposed QRS complexes from the pulmonic flow and TR Doppler signals). However, as these measurements are made on a steep portion of the TR slope, any small timing error can lead to inaccurate calculations of the DPAP.

Fig. 59.10: Estimation of the mean pulmonary artery pressure (MPAP). The RA–RV mean systolic gradient is derived from tracing the tricuspid regurgitation profile and equals 42 mm Hg; adding the RAP gives the MPAP.

Mean Pulmonary Artery Pressure In individuals with a “normal” lung, the pulmonary capillary hydrostatic pressure is equivalent to the PCWP. However, in the presence of pulmonary venoconstriction and PH, there can be a great difference between the lower PCWP and the higher pulmonary capillary hydrostatic pressure. In these situations, the DPAP does not necessarily reflect adequate LA and LVEDP. It is then more important to predict the MPAP, which reflects and classifies more adequately the PAP. The peak PR jet identifies the diastolic pressure gradient between the RV and the PA. Masuyama et al.45 found that application of the Bernoulli equation to the peak PR jet velocity provides an estimation of MPAP (Fig. 59.9). Addition of the RAP improves the accuracy of this estimate.48 Figure 59.10 demonstrates another simple method to evaluate MPAP by adding the RAP to the RA–RV mean systolic gradient, which can be derived from the TR profile.49 As the relationship between SPAP and DPAP has been shown to be constant,50 several empirical formulas listed in Table 59.2 have been suggested for the estimation of the MPAP.42,51 However, these data are derived from invasive studies and have not been validated by Doppler echocardiography.51

Pulmonary Vascular Resistance The PVR is directly proportional to the pressure gradient across the entire lungs from the PAP to the left atrial


pressure (LAP). PVR equals: [(MPAP – mean PCWP) × 80]/CO and is a hemodynamic variable, which contributes to the management of patients with advanced cardiovascular and pulmonary disease. Normal values range between 20 and 130 dynes/s/m/cm–5, which equals 0.25 – 1.6 woods units (WU). While increased SPAP may be secondary to increased backflow from the heart, it can also be the cause of pulmonary vascular disease. An elevated PVR is used to define PH, and it is also an essential component in the evaluation of patients awaiting heart and lung transplantation52 as well as in the determination of which patients should have closure of their intracardiac shunt.53 Elevated values of PVR correlate with worse clinical outcomes and prognosis in many different patient populations.54,55 Initial studies evaluating PVR noninvasively found only weak correlations with invasive monitoring.56 However, using the maximal TR velocity and the RVOT VTI has recently been shown to correlate well with the transpulmonary pressure gradient and transpulmonary flow, respectively (which are the parameters used for invasive estimation of PVR). Using the simple equation: PVR (WU) = 10 × TR velocity/RVOT VTI + 0.16.57 In patients with a ratio of <0.175, there is a low likelihood to have a PVR > 2 WU, practically excluding

1273

pulmonary vascular disease.57 This ratio has been validated in several studies, but in patients with a very high PVR (>8 WU), its reliability as a quantitative measurement is poor.58 Other additional, more complicated methods for estimation of PVR are available59–61 (Table 59.2). To date, there have not been any comparative studies of the various echo-Doppler methods used to assess PVR.

LEFT-SIDED FILLING PRESSURES (TABLE 59.4) Invasive measurements for left-sided filling pressures include the PCWP that reflects the LAP. PCWP also reflects LVEDP, which is the pressure within the left ventricle at the onset of the QRS complex on electrocardiography (ECG) aside from several conditions, which can cause overestimation (mitral stenosis) or underestimation (aortic insufficiency and a noncompliant left ventricle) of it. Noninvasive assessment of left-sided filling pressures (LA and LV) is done using the diastolic function parameters listed in Table 59.4. Left-sided filling pressures are considered elevated when the PCWP is > 12 mm Hg or the LVEDP is > 16 mm Hg62 and elevated filling pressures are the main physiological consequence of diastolic dysfunction.63

Table 59.4: The Various Methods Utilized for the Echocardiographic Evaluation of Left-Sided Filling Pressures (PCWP, LVEDP)

Method

Criteria Used


Mitral inflow parameters: E-wave, A-wave, DT, E/A ratio, IVRT. Measured using pulse wave Doppler in the apical four-chamber view (Fig. 59.11)

• See Table 59.4 for normal values. • Obtainable in nearly all patients • Impaired LV relaxation: E/A < 1 or E/A > 2 • U shape relation with LV diastolic DT prolonged > 240 ms, IVRT prolonged function—similar values for healthy and • Pseudonormal: 1< E/A < 2, 160 < DT those with disease observed < 240 ms Difficult to interpret in the setting of: • Restrictive filling: E/A > 2, DT short – Sinus tachycardia < 160 ms, IVRT short < 70 ms – Conduction system abnormalities See also Table 59.7 – Arrhythmias • Poor correlation in patients with coronary artery disease and those with hypertrophic cardiomyopathy with EF ≥ 50%

Pulmonary venous flow (Figs 59.12A and B)

S > D—Normal S < D—elevated LA pressure or normal in young (<40 years) individuals. ‘Ar’ velocity < 35 cm/s—normal ‘Ar’—A-wave duration < 30 ms—normal LA pressure

• • • •

Depth limitation Marked cardiac enlargement Left atrial motion artifact Influenced by age (D dominant in young individuals < 40 years) Ar duration and velocity: • Not influenced by age • Applicable also in normal LVEF, MV disease, and HCM • Hard to obtain good quality images for interpretation Contd...

1274


Contd... Method

Criteria Used


Tissue Doppler imaging (TDI), see Table 59.5 for normal values. (Fig. 59.13)

é, á, E/é ratio < 8—normal LV filling pressures ≥15 (for septal é) or > 12 (for lateral é)— elevated LV filling pressures

é Reduced with: • Aging • The presence of annular calcifications, annular rings, prosthetic MV, MS Increased with: • Moderate to severe MR • Constrictive pericarditis (lateral may be less than septal in this situation) May be affected by: • Preload in those with normal LVEF • LV relaxation • Systolic function Lateral values higher than septal values á increased by: • Increased LA contractility • Decreased LVEDP E/é • Lateral ratio lower than septal • In patients with normal LVEF has low sensitivity and high specificity • In patients with mitral annular calcification, severe MR, or constrictive pericarditis might not give an adequate estimate of filling pressures. • Might not be valid for patients with acute decompensated heart failure100

Propagation velocity—Vp

Vp > 50 cm/s—normal E/Vp > 2.5—elevated PCWP > 15 mm Hg

Validated in patients with reduced LVEF Poor reproducibility

Aortic (Fig. 59.14) and mitral (Fig. 59.15) regurgitation jet RA and LA shunt (Fig. 59.16)

LVEDP = diastolic BP – (4 × AR jet velocity2) LAP = systolic BP – (4 × MR jet velocity2) Intra atrial pressure difference = 4 × V2

Validated only if no mitral stenosis is present

(DT: Deceleration time; HCM: Hypertrophic cardiomyopathy; IVRT: Isovolumic relaxation time; LA: Left atrium; LAP: Left atrial pressure; LV: Left ventricle; LVEF: Left ventricular ejection fraction; PCWP: Pulmonary capillary wedge pressure, LVEDP: Left ventricular end diastolic pressure; MR: Mitral regurgitation; MS: Mitral stenosis; MV: Mitral valve; RA: Right atrium).

Mitral Inflow Parameters (Fig. 59.11) Using the pulsed wave (PW) Doppler in the apical fourchamber view, assessment of the mitral inflow velocities can be obtained, with images obtainable in nearly all patients. The primary measurements include the peak diastolic early filling (E-wave) and the diastolic late atrial filling (A-wave) velocities, the ratio between these (E/A), the peak velocity deceleration time (DT), A-wave duration, and the IVRT (derived by placing the curser in the left ventricular outflow tract [LVOT] to display simultaneously the end of aortic ejection and onset of mitral inflow).

Normal values of the mitral inflow parameters vary with aging. With increasing age, the E-wave decreases and the DT and A-wave increases in amplitude, causing the E/A ratio to decrease as well. The normal values as per age are shown in Table 59.5.62 As listed in Table 59.6, heart rate and rhythm, PR interval, CO, mitral annular size, and LA function62 as well as other specific factors affect the mitral inflow. It is well established that the mitral E-wave velocity primarily reflects the LA–LV pressure gradient during the early stage of diastole and is thus amenable to changes in the preload and alterations in LV relaxation.62,64 The mitral A-wave velocity reflects the LA–LV pressure


A

1275

B

Figs 59.11A and B: Mitral valve inflow Doppler. Primary measurements include the peak early filling (E) and the late diastolic atrial filling (A) velocities, deceleration time (yellow line) of the E-wave. (A) patient with a normal filling pattern, the E-wave is greater than the A wave with a deceleration time of 206 ms (>160 ms); (B) Restrictive filling pattern, the E-wave is greater than the A-wave with a very short deceleration time of 137 ms. Table 59.5: Normal Values by Age Groups for Doppler and Tissue Doppler Variables for Estimation of Left Heart Hemodynamics

Measurement

Age Group 16–20

21–40

41–60

> 60

E/A ratio

1.88 ± 0.45

1.53 ± 0.4

1.28 ± 0.25

0.96 ± 0.18

DT (ms)

142 ± 19

166 ± 14

181 ± 19

200 ± 29

IVRT (ms)

50 ± 9

67 ± 8

74 ± 7

87 ± 7

Septal é (cm/s)

14.9 ± 2.4

15.5 ± 2.7

12.2 ± 2.3

10.4 ± 2.1

Lateral é (cm/s)

20.6 ± 3.8

19.8 ± 2.9

16.1 ± 2.3

12.9 ± 3.5

Ar duration (ms)

66 ± 39

96 ± 33

112 ± 15

113 ± 30

Source: Adopted from Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009;22(2):107–33.62 Table 59.6: Variables Affecting Mitral Inflow Parameters

Parameter

Variables

General parameters

• • • •

E-wave

• Aging • Preload • Alterations in left ventricular (LV) relaxation

A-wave

• Aging • LV compliance • Left atrial contractile function

E-wave deceleration time (DT)

• Aging • LV relaxation • LV diastolic pressure after mitral valve opening • LV compliance

Heart rate and rhythm PR interval Cardiac output Mitral annular size

gradient during the late stage of diastole, which is affected by LV compliance and the LA contractile function. The DT of the mitral E-wave is influenced by the LV relaxation, LV diastolic pressure after mitral valve (MV) opening, and the LV compliance. Alterations in the LV end-systolic and/or end-diastolic volumes, LV elastic recoil, and/or LV diastolic pressures directly affect the mitral inflow velocities (E-wave) and the time intervals (DT and IVRT).62 In patients with dilated cardiomyopathy, the mitral inflow velocity parameters correlate better with functional class, filling pressures, and prognosis than the calculated left ventricular ejection fraction (LVEF).65–77 However, in patients with coronary artery disease,78 mitral regurgitation (MR), or hypertrophic cardiomyopathy (HCM),79,80 where the LVEF is >50%, mitral inflow variables do not correlate as well with hemodynamic measurements.

1276


With the use of these parameters, especially the E/A ratio and the DT, the echocardiographic filling pattern can be classified to either normal (E > A, DT > 160 ms), impaired LV relaxation (E < A, DT > 240 ms), pseudonormal LV filling (E > A, DT > 160 ms), or restrictive LV filling (E >> A, DT < 140 ms; Fig. 59.11).

Pulmonary venous flow also provides important information for the assessment of LV diastolic function and LA filling pressure. In most patients, the best Doppler recordings are obtained from the apical four-chamber view with the pulmonary venous flow obtainable in ~approximately 90% of adult patients.81 As seen in Figures 59.12A and B, variables include the peak systolic velocity (S), which is composed of two systolic components (S1, S2), peak anterograde diastolic velocity (D), the S/D ratio, and the duration and peak of the atrial reversal (Ar) velocity waveform. The S-wave is primarily influenced by changes in the LA pressure, contraction, and relaxation (S1 component) and by the stroke volume (SV) and pulse wave propagation in the PA vasculature tree.82,83 The ‘D’-wave is influenced by the same factors that influence the mitral E velocity.84 ‘Ar’ duration and velocity are influenced by the LV late diastolic pressure, atrial preload, and contractility.85 With

an increase in LA pressure, there is a decrease in ‘S’ and increase in ‘D’ velocities resulting in an S/D ratio of <1. When there is an increased LVEDP, the Ar velocity and duration increase as well as the time difference between ‘Ar’ duration and the mitral A-wave duration.86,87 Normal values of pulmonary venous inflow are strongly related to age. In young normal subjects, there is usually prominent D velocity, reflecting their mitral E-wave. This gradually declines (age > 40) with an increase in the S/D ratio. The ‘Ar’ velocity also usually increases with age but normal values do not usually exceed 35 cm/s. A duration difference of >30 ms between the ‘Ar’ and the mitral inflow A-wave (‘Ar’–A duration) is the only age-independent indication of LV A-wave pressure increase,88 which can classify patients with abnormal LV relaxation into those with elevated LVEDP but normal mean LA pressure, which is the first hemodynamic abnormality seen with diastolic dysfunction. Other variables such as maximal LA size, E-wave DT, and a pseudonormal filling pattern, are all indicative of an increase in the mean LA pressure and a more advanced stage of diastolic dysfunction.62 Importantly, unlike mitral inflow parameters, the ‘Ar’–A duration difference is still accurate in various patient populations such as those with: normal ejection fraction (EF),78 MV disease,89 and HCM.80 Yet, one of the important limitations using the ‘Ar’ parameters is obtaining high-quality images suitable for accurate reproducible measurements.

A

B

Pulmonary Venous Flow (Figs 59.12A and B)

Figs 59.12A and B: Doppler of the pulmonary vein flow pattern from the apical four-chamber view. (A) normal Doppler study demonstrates the peak systolic velocity (S), which is composed of two systolic components (S1, S2), peak anterograde diastolic velocity (D), and peak of the atrial reversal (Ar) velocity waveform; (B) An examination from a patient with an elevated left atrial filling pressure demonstrating a decrease in S and increase in D, resulting in an S/D ratio of <1.


1277

TDI measurements include both systolic (S) and diastolic velocities. The early diastolic velocities are expressed as Ea, Em, É, or é, and the late diastolic velocity as Aa, Am, Á, or á, with mostly used terms being é and á. TDI is acquired using PW Doppler from the apical views to acquire the mitral annular velocities.90 ASE guidelines62 recommend acquiring and measuring TDI signals from both the septal and lateral sides of the MV annulus. The normal values of these parameters are influenced by age like other indices of LV diastolic function, with a decrease in é and an increase in á and the E/é ratio;91 normal values are shown in Table 59.5. The hemodynamic determinants of the é velocity include LV relaxation, preload, systolic function, and LV minimal pressure.62 A significant association between é and LV relaxation has been shown in several studies.92,93 While preload has minimal effect on é in the presence of LV impaired relaxation,94,95 it increases é in patients with normal or enhanced LV relaxation.94–97 Due to this, in patients with cardiac disease, é velocity can be used to correct for the effect of LV relaxation on mitral E velocity, and the E/é ratio can be applied for the prediction of LV filling pressures (Figs 59.13A and B).62 The main determinants of á include LA systolic function and LVEDP such that increased LA contractility leads to increased á velocity, whereas increased LVEDP leads to decreased á velocity.94 Once acquired, it is possible to also calculate

additional time intervals and ratios using a combination of TDI and mitral inflow parameters such as the E velocity to é ratio (E/é), which plays an important role in the estimation of LV filling pressures. The time differential between the QRS and both E and é gives the TE-é and also provides additional information on diastolic function. TE-é is prolonged in patients with diastolic dysfunction. The combination of TDI and mitral inflow velocities allows for prediction of LV filling pressures. However, it is important to take into context the clinical parameters in order to make a reliable assessment (i.e. age, presence of cardiovascular disease, other echocardiographic abnormalities). Unfortunately, these criteria are limited in their accuracy for LV filling pressures. It is recommended to use the average é velocity obtained from both the lateral and septal sides of the mitral annulus for the prediction of LV filling pressure. The septal é is usually lower than the lateral é velocity, so the E/é ratio from the septal signal is usually higher than the lateral é. In the context of regional myocardial dysfunction, it is recommended by the ASE to use the average é velocity, and in patient with atrial fibrillation an average of measurements from 10 cardiac cycles is most accurate. An E/é ratio of <8 (for either septal or lateral) is usually associated with normal LV filling pressures. Conversely, a ratio ≥ 15 for septal or ≥ 12 for lateral é is associated with increased LV filling pressures.62 When the value is midrange (between 8 and 15), other indices should be used to assess LV filling pressures. In these patients and also in those with

A

B

Tissue Doppler Annular Early and Late Diastolic Velocities (Fig. 59.13)

Figs 59.13A and B: Evaluation of left-sided filling pressures. (A) Mitral inflow velocities are measured (E, A), showing an E > A with a pseudonormal filling pattern (deceleration time > 160 ms); (B) Lateral tissue Doppler imaging (TDI) that includes both systolic (S) and diastolic velocities. The early diastolic velocity is expressed as é, and the late diastolic velocity as á. In this patient, the E/é is elevated and equals—89/4.66 = 19, implying elevated left-sided filling pressures.

1278


normal EF, or with MV disease, using the TE-é might provide additional input. It has been also shown in more recent studies that in those with normal EF, the lateral é has the best correlation with LV filling pressures and invasive parameters of LV stiffness.98,99 It is controversial whether in patients with acute decompensated heart failure E/é is valid.100–102

Color M-mode Flow Propagation Velocity (Vp) The left ventricular filing is dominated by an early wave and an atrial-induced filling wave. In a normal ventricle, the early filling forces are attributed to suction of blood from the atria and the filling wave propagates rapidly toward the apex, driven by the pressure gradient between the LV base and the apex. Using of color flow imaging and M-mode echocardiography placed through the center of the LV inflow from the MV to the apex, the propagation velocity can be estimated. A Vp > 50 cm/s is considered normal,103,104 while in patients with myocardial ischemia or heart failure there is slowing of the mitral to apical flow propagation measured. In patients with reduced LVEF (< 50%), the E/Vp ratio can be used to predict the LV filling pressures,104 with E/Vp ≥ 2.5 predicting a PCWP of >15 mm Hg.98

However, Vp is often not routinely evaluated due to poor reproducibility and limited sensitivity and specificity. In addition, other signs of ventricular impairment and filling pressure are usually apparent during the echocardiographic evaluation, making Vp useful as a complimentary index when there are inconsistent findings. In patients with a normal LVEF, Vp can be falsely normal despiteelevated filling pressures.105,106

Left Atrial Dimensions Chronic elevation of left-sided filling pressures leads to LA enlargement. There is a significant association between LA dimensions and elevated left-sided filling pressures and evaluation of LA dimensions is an important adjunct to the echocardiographic evaluation of the left-sided filling pressures.107 LA measurements are usually obtained most accurately from the apical views.14 However, LA enlargement is not a specific sign for elevated filling pressures as it can accompany also situations where the left-sided filling pressures are not elevated and diastolic dysfunction is not present such as in trained athletes, patients with chronic atrial fibrillation or flutter, bradycardia, high output states and mitral valvular disease. Mitral inflow pattern, PV flow, TDI and Vp can serve as useful tools for evaluation and estimation of left-sided filling pressures. Table 59.7 lists the main differences

Table 59.7: Variables Used for the Evaluation of Filling Pressures in Those with Normal and with Decreased Ejection Fraction (EF)

Variable

Patients with Depressed EF

Patients with Normal EF

E/A

< 1 Normal FP (if E ≤ 50 cm/s) ≥ 1–<2, < 1 and E > 50 cm/s—indeterminate ≥ 2 – elevated FP (with DT < 150 ms)

NA

E/é

< 8—normal FP 8–12—indeterminate ≥ 13—elevated FP

≤ 8 (Sep, Lat, Avg)—normal FP Sep ≥ 15, Lat ≥ 12, Avg ≥ 13—elevated FP

Vp

> 50 cm/s—normal E/Vp > 2.5—elevated FP >15 mm Hg

Can be falsely normal despite elevated FP

Ar-A

< 0 ms—normal FP 0–29—indeterminate ≥ 30 ms—elevated FP

< 0 ms—normal FP 0–29—indeterminate ≥ 30 ms—elevated FP

IVRT/TE-é

> 2—normal FP < 2—elevated FP

> 2—normal FP < 2—elevated FP

Systolic pulmonary artery pressure

< 30 mm Hg—normal FP > 35 mm Hg—elevated FP

< 30 mm Hg—normal FP > 35 mm Hg—elevated FP

Pulmonary vein S/D

> 1—normal FP < 1—Elevated FP

Limited accuracy

Left atrial volume

Some LA dilation may occur in this population < 34 mL/m2—normal FP in the presence of normal FP. Thus, this param- ≥ 34 mL/m2—Elevated FP eter should not be used in this population.

(Avg: Average; EF: Ejection fraction; FP: Filling pressure; Lat: Lateral; NA: Not applicable; Sep: Septal).


in the evaluation of filling pressures in patients with either a decreased or a normal LVEF. While in patients with impaired myocardial function the primary tool for evaluation is the E/A ratio, in those with a normal LVEF the estimation can be more challenging, primarily assessed using the E/é ratio preferably with the use of other parameters.107 A simplified diagnostic algorithm for the evaluation of different patient populations based on the ASE regarding the evaluation of left ventricular diastolic function62 is shown in Figure 59.14.

ADDITIONAL PARAMETERS FOR ESTIMATION OF LEFT ATRIAL PRESSURE Aortic and Mitral Regurgitation Continuous Wave Doppler Signal The LAP equals the LVEDP in the absence of mitral stenosis. In patients with aortic regurgitation (AR), using the continuous wave (CW) Doppler signal of the AR jet gives the pressure gradient between the aorta and the LV at end diastole. Peak AR velocity should be >4 m/s, and the

1279

LVEDP can be calculated as the diastolic aortic pressure minus the pressure gradient at end diastole which, by using the modified Bernoulli equation, is equal to 4V2 (Fig. 59.15). Diastolic blood pressure should be obtained at the same time the AR jet is being interrogated. The maximal pressure gradient between the LV and LA during systole can be determined by CW Doppler in patients with MR. LAP can be calculated as the difference between the systolic blood pressure and the MR gradient, by using the modified Bernoulli equation as well (Fig. 59.16). In patients with mitral stenosis, the LA diastolic pressure is the sum of the LVEDP and the transmitral gradient. Again, care must be taken to obtain blood pressure at the same time as Doppler measurements are being obtained.108

Atrial Septal Defect/Patent Foramen Ovale Flow As shown in Figure 59.17, by adding the estimated RAP to the pressure gradient between the RA and the LA as evaluated by CW Doppler, it is possible to estimate the LAP.

Fig. 59.14: Schematic approach for the evaluation of left-sided filling pressures using the various obtained echocardiographic parameters. (DT: Deceleration time; IVRT: Isovolumic relaxation time; LA: Left atrium; PV: Pulmonary vein; SPAP: Systolic pulmonary artery pressure). *Refers for averaged values from both septal and lateral tissue Doppler; for specific values see Table 7. **See text for further details. Adopted from Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009;22(2):107–33.62

1280


Fig. 59.15: Measurement of left ventricular end diastolic pressure (LVEDP) using the aortic regurgitation (AR) signal. Using continuous wave Doppler through the aortic valve in diastole, the end-diastolic AR velocity gives out the pressure gradient (white arrow) which equals to 4 × 3.42 = 46 mm Hg. Subtracting this value from the systolic blood pressure gives an estimate of the left atrial pressure during systole (V-wave). The LVEDP equals the diastolic blood pressure—4V2.

Fig. 59.16: Estimation of the pressure gradient between the left ventricle and left atrium (LA). Using continuous wave Doppler through the mitral valve in systole, the peak MR velocity gives out the maximal pressure gradient (white arrow), which equals to 4 × 4.872 = 95 mm Hg. Subtracting this value from the systolic blood pressure gives an estimate of the LA pressure during systole (V-wave).

STROKE VOLUME, STROKE DISTANCE, CARDIAC OUTPUT, AND SYSTEMIC PULMONARY SHUNTS (QP/QS)

the absence of pulmonic shunting, the pulmonic outflow tract can be used instead of the LVOT.111 By determining the transmitral and transpulmonary flow, it is possible to noninvasively obtain the pulmonic to systemic flow ratio (QP/QS) in various shunt disease, if present. However, calculation of pulmonary flow can sometimes result in significant errors, mainly due to the inability to adequately visualize and measure the PA diameter or RVOT diameter. As the case in severe AR, significant PR can lead to overestimation of the right ventricular SV. While in patients with severe AR, Doppler can falsely underestimate the QP/QS, in those with significant PR it can lead to falsely overestimating it.

CO equals SV multiplied by the heart rate (CO = SV × heart rate). Using Doppler, it is possible to measure the stroke distance, which refers to the distance traveled by a column of blood during a fixed time (the cardiac cycle). Multiplying the stroke distance with the cross-sectional area through which the column moves gives the SV. This method can be obtained at several sites, with the most common and accurate being the LVOT109,110 (Fig. 59.18). It is necessary that Doppler velocities be obtained parallel to the direction of flow and that the cross-sectional area through which the flow is occurring is obtained. As the outflow tract is often elliptical and not circular, it may be more appropriate to use the stroke distance rather than the CO, as it may be miscalculated due to the aortic annulus being elliptical. Significant AR will lead to overestimation of the SV and consequently the CO. When present, and in

A WORD TO CONCLUDE As noninvasive evaluation utilizes indirect indexes for estimation of hemodynamic parameters, it is far superior to bedside physical examination but it also has limitations. However, in addition to providing hemodynamic data and volume status, the Doppler data provides insight into the pathophysiology of ventricular filling and emptying.


Fig. 59.17: Estimation of the left atrial (LA) pressure. On the top image: color flow imaging demonstrating a shunt between the right atrium (RA) and LA. On the bottom image: continuous wave Doppler for estimation of the pressure gradient between the RA and the LA (white arrow), which equals 4 × 2.742 = 30 mm Hg. Adding this gradient to the estimated RAP gives the estimated LA pressure.

REFERENCES 1. Gore JM, Goldberg RJ, Spodick DH, et al. A communitywide assessment of the use of pulmonary artery catheters in patients with acute myocardial infarction. Chest. 1987;92(4):721–7. 2. Harvey S, Harrison DA, Singer M, et al. PAC-Man study collaboration. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): a randomised controlled trial. Lancet. 2005;366(9484):472–7. 3. Ivanov RI, Allen J, Sandham JD, et al. Pulmonary artery catheterization: a narrative and systematic critique of randomized controlled trials and recommendations for the future. New Horiz. 1997;5(3):268–76.

1281

Fig. 59.18: Estimation of stroke volume (SV) and cardiac output (CO). Using Doppler, the left ventricular outflow tract velocity time integral (LVOT VTI) is measured, and is 11.5 cm. This is the stroke distance (SD). Multiplying the stroke distance with the crosssectional area through which the SD moves gives the SV. As the LVOT diameter is 2 cm, the cross-sectional area is × (2/2)2 = 3.14. The SV is thus 36 mL. The CO = SV × heart rate, which is 3.2 L/min. *As the outflow tract is elliptical and not circular, averaging measurements from at least two different planes is recommended for better estimation.

4. Connors AF Jr, Speroff T, Dawson NV, et al. The effectiveness of right heart catheterization in the initial care of critically ill patients. SUPPORT Investigators. JAMA. 1996;276(11): 889–97. 5. Shah MR, Hasselblad V, Stevenson LW, et al. Impact of the pulmonary artery catheter in critically ill patients: metaanalysis of randomized clinical trials. JAMA. 2005; 294(13): 1664–70. 6. Drazner MH, Rame JE, Stevenson LW, et al. Prognostic importance of elevated jugular venous pressure and a third heart sound in patients with heart failure. N Engl J Med. 2001;345(8):574–81. 7. Morley D, Brozena SC. Assessing risk by hemodynamic profile in patients awaiting cardiac transplantation. Am J Cardiol. 1994;73(5):379–83.

1282


8. Damman K, van Deursen VM, Navis G, et al. Increased central venous pressure is associated with impaired renal function and mortality in a broad spectrum of patients with cardiovascular disease. J Am Coll Cardiol. 2009;53(7): 582–8. 9. Unverferth DV, Magorien RD, Moeschberger ML, et al. Factors influencing the one-year mortality of dilated cardiomyopathy. Am J Cardiol. 1984;54(1):147–52. 10. Dellinger RP, Levy MM, Carlet JM, et al. International Surviving Sepsis Campaign Guidelines Committee; American Association of Critical-Care Nurses; American College of Chest Physicians; American College of Emergency Physicians; Canadian Critical Care Society; European Society of Clinical Microbiology and Infectious Diseases; European Society of Intensive Care Medicine; European Respiratory Society; International Sepsis Forum; Japanese Association for Acute Medicine; Japanese Society of Intensive Care Medicine; Society of Critical Care Medicine; Society of Hospital Medicine; Surgical Infection Society; World Federation of Societies of Intensive and Critical Care Medicine. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008. Crit Care Med. 2008;36(1): 296–327. 11. Michard F, Teboul JL. Predicting fluid responsiveness in ICU patients: a critical analysis of the evidence. Chest. 2002;121(6):2000–8. 12. Wexler L, Bergel DH, Gabe IT, et al. Velocity of blood flow in normal human venae cavae. Circ Res. 1968;23(3): 349–59. 13. Gabe IT, Gault JH, Ross J Jr, et al. Measurement of instantaneous blood flow velocity and pressure in conscious man with a catheter-tip velocity probe. Circulation. 1969;40(5): 603–14. 14. Lang RM, Bierig M, Devereux RB, et al. Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 15. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685–713; quiz 786. 16. Nakao S, Come PC, McKay RG, et al. Effects of positional changes on inferior vena caval size and dynamics and correlations with right-sided cardiac pressure. Am J Cardiol. 1987;59(1):125–32.

17. Jue J, Chung W, Schiller NB. Does inferior vena cava size predict right atrial pressures in patients receiving mechanical ventilation? J Am Soc Echocardiogr. 1992; 5(6):613–9. 18. Goldhammer E, Mesnick N, Abinader EG, et al. Dilated inferior vena cava: a common echocardiographic finding in highly trained elite athletes. J Am Soc Echocardiogr. 1999;12(11):988–93. 19. Reynolds T, Appleton CP. Doppler flow velocity patterns of the superior vena cava, inferior vena cava, hepatic vein, coronary sinus, and atrial septal defect: a guide for the echocardiographer. J Am Soc Echocardiogr. 1991;4(5): 503–12. 20. Sivaciyan V, Ranganathan N. Transcutaneous doppler jugular venous flow velocity recording. Circulation. 1978; 57(5):930–9. 21. Appleton CP, Hatle LK, Popp RL. Superior vena cava and hepatic vein Doppler echocardiography in healthy adults. J Am Coll Cardiol. 1987;10(5):1032–9. 22. Appleton CP, Hatle LK, Popp RL. Demonstration of restrictive ventricular physiology by Doppler echocardiography. J Am Coll Cardiol. 1988;11(4):757–68. 23. Ghio S, Recusani F, Sebastiani R, et al. Doppler velocimetry in superior vena cava provides useful information on the right circulatory function in patients with congestive heart failure. Echocardiography. 2001;18(6):469–77. 24. Nagueh SF, Kopelen HA, Zoghbi WA. Relation of mean right atrial pressure to echocardiographic and Doppler parameters of right atrial and right ventricular function. Circulation. 1996;93(6):1160–9. 25. Abbas A, Lester S, Moreno FC, Srivathsan K, Fortuin D, Appleton C. Noninvasive assessment of right atrial pressure using Doppler tissue imaging. J Am Soc Echocardiogr. 2004;17(11):1155–60. 26. Nageh MF, Kopelen HA, Zoghbi WA, et al. Estimation of mean right atrial pressure using tissue Doppler imaging. Am J Cardiol. 1999;84(12):1448–51, A8. 27. Patel AR, Alsheikh-Ali AA, Mukherjee J, et al. 3D echocardiography to evaluate right atrial pressure in acutely decompensated heart failure correlation with invasive hemodynamics. JACC Cardiovasc Imaging. 2011;4(9): 938–45. 28. Yoshida K, Yoshikawa J, Shakudo M, et al. Color Doppler evaluation of valvular regurgitation in normal subjects. Circulation. 1988;78(4):840–7. 29. Klein AL, Burstow DJ, Tajik AJ, et al. Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers. J Am Soc Echocardiogr. 1990;3(1):54–63. 30. Okura H, Takada Y, Yamabe A, et al. Prevalence and correlates of physiological valvular regurgitation in healthy subjects. Circ J. 2011;75(11):2699–704. 31. Lanzarini L, Fontana A, Campana C, Klersy C. Two simple echo-Doppler measurements can accurately identify pulmonary hypertension in the large majority of patients with chronic heart failure. J Heart Lung Transplant. 2005; 24(6):745–54.


32. Dabestani A, Mahan G, Gardin JM, et al. Evaluation of pulmonary artery pressure and resistance by pulsed Doppler echocardiography. Am J Cardiol. 1987;59(6): 662–8. 33. Currie PJ, Seward JB, Chan KL, et al. Continuous wave Doppler determination of right ventricular pressure: a simultaneous Doppler-catheterization study in 127 patients. J Am Coll Cardiol. 1985;6(4):750–6. 34. Berger M, Haimowitz A, Van Tosh A, et al. Quantitative assessment of pulmonary hypertension in patients with tricuspid regurgitation using continuous wave Doppler ultrasound. J Am Coll Cardiol. 1985;6(2):359–65. 35. Fisher MR, Criner GJ, Fishman AP, et al. NETT Research Group. Estimating pulmonary artery pressures by echocardiography in patients with emphysema. Eur Respir J. 2007;30(5):914–21. 36. Arcasoy SM, Christie JD, Ferrari VA, et al. Echocardiographic assessment of pulmonary hypertension in patients with advanced lung disease. Am J Respir Crit Care Med. 2003;167(5):735–40. 37. Horton KD, Meece RW, Hill JC. Assessment of the right ventricle by echocardiography: a primer for cardiac sonographers. J Am Soc Echocardiogr. 2009;22(7):776–92; quiz 861. 38. de Divitiis O, Fazio S, Petitto M, et al. Obesity and cardiac function. Circulation. 1981;64(3):477–82. 39. Lam CS, Borlaug BA, Kane GC, et al. Age-associated increases in pulmonary artery systolic pressure in the general population. Circulation. 2009;119(20):2663–70. 40. Jeon DS, Luo H, Iwami T, et al. The usefulness of a 10% air10% blood-80% saline mixture for contrast echocardiography: Doppler measurement of pulmonary artery systolic pressure. J Am Coll Cardiol. 2002;39(1):124–9. 41. Tan HC, Fung KC, Kritharides L. Agitated colloid is superior to saline and equivalent to levovist in enhancing tricuspid regurgitation Doppler envelope and in the opacification of right heart chambers: a quantitative, qualitative, and costeffectiveness study. J Am Soc Echocardiogr. 2002;15(4): 309–15. 42. Dini FL, Traversi E, Franchini M, et al. Contrast-enhanced Doppler hemodynamics for noninvasive assessment of patients with chronic heart failure and left ventricular systolic dysfunction. J Am Soc Echocardiogr. 2003;16(2): 124–31. 43. Rapp AH, Lange RA, Cigarroa JE, et al. Relation of pulmonary arterial diastolic and mean pulmonary arterial wedge pressures in patients with and without pulmonary hypertension. Am J Cardiol. 2001; 88(7):823–4. 44. Lee RT, Lord CP, Plappert T, et al. Prospective Doppler echocardiographic evaluation of pulmonary artery diastolic pressure in the medical intensive care unit. Am J Cardiol. 1989;64(19):1366–70. 45. Masuyama T, Kodama K, Kitabatake A, et al. Continuouswave Doppler echocardiographic detection of pulmonary regurgitation and its application to noninvasive estimation of pulmonary artery pressure. Circulation. 1986;74(3): 484–92.

1283

46. Reynolds DW, Bartelt N, Taepke R, et al. Measurement of pulmonary artery diastolic pressure from the right ventricle. J Am Coll Cardiol. 1995;25(5):1176–82. 47. Stephen B, Dalal P, Berger M, et al. Noninvasive estimation of pulmonary artery diastolic pressure in patients with tricuspid regurgitation by Doppler echocardiography. Chest. 1999;116(1):73–7. 48. Abbas AE, Fortuin FD, Schiller NB, et al. Echocardiographic determination of mean pulmonary artery pressure. Am J Cardiol. 2003;92(11):1373–6. 49. Aduen JF, Castello R, Lozano MM, et al. An alternative echocardiographic method to estimate mean pulmonary artery pressure: diagnostic and clinical implications. J Am Soc Echocardiogr. 2009;22(7):814–9. 50. Syyed R, Reeves JT, Welsh D, et al. The relationship between the components of pulmonary artery pressure remains constant under all conditions in both health and disease. Chest. 2008; 133(3):633–9. 51. Chemla D, Castelain V, Humbert M, et al. New formula for predicting mean pulmonary artery pressure using systolic pulmonary artery pressure. Chest. 2004;126(4):1313–7. 52. Canter CE, Shaddy RE, Bernstein D, et al. American Heart Association Council on Cardiovascular Disease in the Young; American Heart Association Council on Clinical Cardiology; American Heart Association Council on Cardiovascular Nursing; American Heart Association Council on Cardiovascular Surgery and Anesthesia; Quality of Care and Outcomes Research Interdisciplinary Working Group. Indications for heart transplantation in pediatric heart disease: a scientific statement from the American Heart Association Council on Cardiovascular Disease in the Young; the Councils on Clinical Cardiology, Cardiovascular Nursing, and Cardiovascular Surgery and Anesthesia; and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. 2007;115(5):658–76. 53. Bhatt DD, Manoj R, Mahajan R. Estimation of pulmonary vascular resistance: correlation between echocardiography and catheterization data in patients with congenital heart disease. Echocardiography. 2012;29(4):478–83. 54. Galiè N, Torbicki A, Barst R, et al. Grupo de Trabajo sobre el diagnóstico y tratamiento de la Hipertensión Arterial Pulmonar de la Sociedad Europea de Cardiología. [Guidelines on diagnosis and treatment of pulmonary arterial hypertension]. Rev Esp Cardiol. 2005;58(5): 523–66. 55. Farzaneh-Far R, Na B, Whooley MA, et al. Usefulness of noninvasive estimate of pulmonary vascular resistance to predict mortality, heart failure, and adverse cardiovascular events in patients with stable coronary artery disease (from the Heart and Soul Study). Am J Cardiol. 2008;101(6): 762–6. 56. Martin-Duran R, Larman M, Trugeda A, et al. Comparison of Doppler-determined elevated pulmonary arterial pressure with pressure measured at cardiac catheterization. Am J Cardiol. 1986;57(10):859–63.

1284


57. Abbas AE, Fortuin FD, Schiller NB, et al. A simple method for noninvasive estimation of pulmonary vascular resistance. J Am Coll Cardiol. 2003;41(6):1021–7. 58. Rajagopalan N, Simon MA, Suffoletto MS, et al. Noninvasive estimation of pulmonary vascular resistance in pulmonary hypertension. Echocardiography. 2009;26(5):489–94. 59. Scapellato F, Temporelli PL, Eleuteri E, et al. Accurate noninvasive estimation of pulmonary vascular resistance by Doppler echocardiography in patients with chronic failure heart failure. J Am Coll Cardiol. 2001;37(7):1813–9. 60. Haddad F, Zamanian R, Beraud AS, et al. A novel non-invasive method of estimating pulmonary vascular resistance in patients with pulmonary arterial hypertension. J Am Soc Echocardiogr. 2009;22(5):523–9. 61. Gurudevan SV, Malouf PJ, Kahn AM, et al. Noninvasive assessment of pulmonary vascular resistance using Doppler tissue imaging of the tricuspid annulus. J Am Soc Echocardiogr. 2007;20(10):1167–71. 62. Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009; 22(2):107–33. 63. Brutsaert DL, Sys SU, Gillebert TC. Diastolic failure: pathophysiology and therapeutic implications. J Am Coll Cardiol. 1993;22(1):318–25. 64. Appleton CP, Hatle LK, Popp RL. Relation of transmitral flow velocity patterns to left ventricular diastolic function: new insights from a combined hemodynamic and Doppler echocardiographic study. J Am Coll Cardiol. 1988;12(2): 426–40. 65. Vanoverschelde JL, Raphael DA, Robert AR, et al. Left ventricular filling in dilated cardiomyopathy: relation to functional class and hemodynamics. J Am Coll Cardiol. 1990;15(6):1288–95. 66. Pinamonti B, Di Lenarda A, Sinagra G, et al. Restrictive left ventricular filling pattern in dilated cardiomyopathy assessed by Doppler echocardiography: clinical, echocardiographic and hemodynamic correlations and prognostic implications. Heart Muscle Disease Study Group. J Am Coll Cardiol. 1993;22(3):808–15. 67. Giannuzzi P, Imparato A, Temporelli PL, et al. Dopplerderived mitral deceleration time of early filling as a strong predictor of pulmonary capillary wedge pressure in postinfarction patients with left ventricular systolic dysfunction. J Am Coll Cardiol. 1994;23(7):1630–37. 68. Pozzoli M, Capomolla S, Pinna G, et al. Doppler echocardiography reliably predicts pulmonary artery wedge pressure in patients with chronic heart failure with and without mitral regurgitation. J Am Coll Cardiol. 1996;27(4): 883–93. 69. Xie GY, Berk MR, Smith MD, et al. Prognostic value of Doppler transmitral flow patterns in patients with congestive heart failure. J Am Coll Cardiol. 1994;24(1): 132–9. 70. Rihal CS, Nishimura RA, Hatle LK, et al. Systolic and diastolic dysfunction in patients with clinical diagnosis of dilated cardiomyopathy. Relation to symptoms and prognosis. Circulation. 1994;90(6):2772–9.

71. Traversi E, Pozzoli M, Cioffi G, et al. Mitral flow velocity changes after 6 months of optimized therapy provide important hemodynamic and prognostic information in patients with chronic heart failure. Am Heart J. 1996;132 (4):809–19. 72. Giannuzzi P, Temporelli PL, Bosimini E, et al. Independent and incremental prognostic value of Doppler-derived mitral deceleration time of early filling in both symptomatic and asymptomatic patients with left ventricular dysfunction. J Am Coll Cardiol. 1996;28(2):383–90. 73. Hansen A, Haass M, Zugck C, et al. Prognostic value of Doppler echocardiographic mitral inflow patterns: implications for risk stratification in patients with chronic congestive heart failure. J Am Coll Cardiol. 2001;37(4): 1049–55. 74. Whalley GA, Doughty RN, Gamble GD, et al. Pseudonormal mitral filling pattern predicts hospital re-admission in patients with congestive heart failure. J Am Coll Cardiol. 2002;39(11):1787–95. 75. Bella JN, Palmieri V, Roman MJ, et al. Mitral ratio of peak early to late diastolic filling velocity as a predictor of mortality in middle-aged and elderly adults: the Strong Heart Study. Circulation. 2002;105(16):1928–33. 76. Pinamonti B, Zecchin M, Di Lenarda A, et al. Persistence of restrictive left ventricular filling pattern in dilated cardiomyopathy: an ominous prognostic sign. J Am Coll Cardiol. 1997;29(3):604–12. 77. Temporelli PL, Corrà U, Imparato A, et al. Reversible restrictive left ventricular diastolic filling with optimized oral therapy predicts a more favorable prognosis in patients with chronic heart failure. J Am Coll Cardiol. 1998; 31(7):1591–7. 78. Yamamoto K, Nishimura RA, Chaliki HP, et al. Determination of left ventricular filling pressure by Doppler echocardiography in patients with coronary artery disease: critical role of left ventricular systolic function. J Am Coll Cardiol. 1997;30(7):1819–26. 79. Nishimura RA, Appleton CP, Redfield MM, et al. Noninvasive Doppler echocardiographic evaluation of left ventricular filling pressures in patients with cardiomyopathies: a simultaneous Doppler echocardiographic and cardiac catheterization study. J Am Coll Cardiol. 1996;28(5):1226–33. 80. Nagueh SF, Lakkis NM, Middleton KJ, et al. Doppler estimation of left ventricular filling pressures in patients with hypertrophic cardiomyopathy. Circulation. 1999;99(2): 254–61. 81. Jensen JL, Williams FE, Beilby BJ, et al. Feasibility of obtaining pulmonary venous flow velocity in cardiac patients using transthoracic pulsed wave Doppler technique. J Am Soc Echocardiogr. 1997;10(1):60–6. 82. Appleton CP. Hemodynamic determinants of Doppler pulmonary venous flow velocity components: new insights from studies in lightly sedated normal dogs. J Am Coll Cardiol. 1997;30(6):1562–74. 83. Smiseth OA, Thompson CR, Lohavanichbutr K, et al. The pulmonary venous systolic flow pulse–its origin and relationship to left atrial pressure. J Am Coll Cardiol. 1999; 34(3):802–9.


84. Nishimura RA, Abel MD, Hatle LK, et al. Relation of pulmonary vein to mitral flow velocities by transesophageal Doppler echocardiography. Effect of different loading conditions. Circulation. 1990;81(5):1488–97. 85. Keren G, Bier A, Sherez J, et al. Atrial contraction is an important determinant of pulmonary venous flow. J Am Coll Cardiol. 1986;7(3):693–5. 86. Rossvoll O, Hatle LK. Pulmonary venous flow velocities recorded by transthoracic Doppler ultrasound: relation to left ventricular diastolic pressures. J Am Coll Cardiol. 1993; 21(7):1687–96. 87. Yamamoto K, Nishimura RA, Burnett JC Jr, et al. Assessment of left ventricular end-diastolic pressure by Doppler echocardiography: contribution of duration of pulmonary venous versus mitral flow velocity curves at atrial contraction. J Am Soc Echocardiogr. 1997;10(1):52–9. 88. Klein AL, Tajik AJ. Doppler assessment of pulmonary venous flow in healthy subjects and in patients with heart disease. J Am Soc Echocardiogr. 1991;4(4):379–92. 89. Rossi A, Cicoira M, Golia G, et al. Mitral regurgitation and left ventricular diastolic dysfunction similarly affect mitral and pulmonary vein flow Doppler parameters: the advantage of end-diastolic markers. J Am Soc Echocardiogr. 2001;14(6):562–8. 90. Waggoner AD, Bierig SM. Tissue Doppler imaging: a useful echocardiographic method for the cardiac sonographer to assess systolic and diastolic ventricular function. J Am Soc Echocardiogr. 2001;14(12):1143–52. 91. De Sutter J, De Backer J, Van de Veire N, et al. Effects of age, gender, and left ventricular mass on septal mitral annulus velocity (E’) and the ratio of transmitral early peak velocity to E’ (E/E’). Am J Cardiol. 2005;95(8):1020–3. 92. Sohn DW, Chai IH, Lee DJ, et al. Assessment of mitral annulus velocity by Doppler tissue imaging in the evaluation of left ventricular diastolic function. J Am Coll Cardiol. 1997;30(2):474–80. 93. Ommen SR, Nishimura RA, Appleton CP, et al. Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: A comparative simultaneous Doppler-catheterization study. Circulation. 2000;102(15):1788–94. 94. Nagueh SF, Sun H, Kopelen HA, Middleton KJ, Khoury DS. Hemodynamic determinants of the mitral annulus diastolic velocities by tissue Doppler. J Am Coll Cardiol. 2001;37(1):278–85. 95. Hasegawa H, Little WC, Ohno M, et al. Diastolic mitral annular velocity during the development of heart failure. J Am Coll Cardiol. 2003;41(9):1590–97. 96. Firstenberg MS, Levine BD, Garcia MJ, et al. Relationship of echocardiographic indices to pulmonary capillary wedge pressures in healthy volunteers. J Am Coll Cardiol. 2000; 36(5):1664–9. 97. Caiani EG, Weinert L, Takeuchi M, et al. Evaluation of alterations on mitral annulus velocities, strain, and strain rates due to abrupt changes in preload elicited by parabolic flight. J Appl Physiol. 2007;103(1):80–7.

1285

98. Rivas-Gotz C, Manolios M, Thohan V, et al. Impact of left ventricular ejection fraction on estimation of left ventricular filling pressures using tissue Doppler and flow propagation velocity. Am J Cardiol. 2003;91(6):780–4. 99. Kasner M, Westermann D, Steendijk P, et al. Utility of Doppler echocardiography and tissue Doppler imaging in the estimation of diastolic function in heart failure with normal ejection fraction: a comparative Doppler-conductance catheterization study. Circulation. 2007;116(6): 637–47. 100. Mullens W, Borowski AG, Curtin RJ, et al. Tissue Doppler imaging in the estimation of intracardiac filling pressure in decompensated patients with advanced systolic heart failure. Circulation. 2009;119(1):62–70. 101. Nagueh SF; ASE and EAE Diastology Writing Group. Letter by Nagueh et al. regarding article, “Tissue Doppler imaging in the estimation of intracardiac filling pressure in decompensated patients with advanced systolic heart failure”. Circulation. 2009;120(7):e44. 102. Galderisi M, Esposito R. Letter by Galderisi and Esposito regarding article, “Tissue Doppler imaging in the estimation of intracardiac filling pressure in decompensated patients with advanced systolic heart failure”. Circulation. 2009;120(7):e46. 103. Takatsuji H, Mikami T, Urasawa K, et al. A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography. J Am Coll Cardiol. 1996;27(2):365–71. 104. Garcia MJ, Ares MA, Asher C, et al. An index of early left ventricular filling that combined with pulsed Doppler peak E velocity may estimate capillary wedge pressure. J Am Coll Cardiol. 1997;29(2):448–54. 105. Lin SK, Hsiao SH, Lee TY, et al. Color M-mode flow propagation velocity: is it really preload independent? Echocardiography. 2005;22(8):636–41. 106. Hsiao SH, Huang WC, Sy CL, et al. Doppler tissue imaging and color M-mode flow propagation velocity: are they really preload independent? J Am Soc Echocardiogr. 2005; 18(12):1277–84. 107. Rafique AM, Phan A, Tehrani F, et al. Transthoracic echocardiographic parameters in the estimation of pulmonary capillary wedge pressure in patients with present or previous heart failure. Am J Cardiol. 2012;110(5):689–94. 108. Ahmed SN, Syed FM, Porembka DT. Echocardiographic evaluation of hemodynamic parameters. Crit Care Med. 2007;35(8 Suppl):S323–9. 109. Lewis JF, Kuo LC, Nelson JG, et al. Pulsed Doppler echocardiographic determination of stroke volume and cardiac output: clinical validation of two new methods using the apical window. Circulation. 1984;70(3):425–31. 110. Dubin J, Wallerson DC, Cody RJ, et al. Comparative accuracy of Doppler echocardiographic methods for clinical stroke volume determination. Am Heart J. 1990;120(1):116–23. 111. Kirkpatrick JN, Lang RM. Heart failure: hemodynamic assessment using echocardiography. Curr Cardiol Rep. 2008;10(3):240–6.

SECTION 5 Ischemic Heart Disease, Cardiomyopathies, Pericardial Disorders, Tumors and Masses

Chapters Chapter 60 Chapter 61 Chapter 62 Chapter 63 Chapter 64

Echocardiography in Ischemic Heart Disease Stress Echocardiography Squatting Stress Echocardiography Three-Dimensional Stress Echocardiography Echocardiographic Assessment of Coronary Arteries —Morphology and Coronary Flow Reserve Chapter 65 Echocardiography in Hypertrophic Cardiomyopathy Chapter 66 Echocardiographic Assessment of Nonobstructive Cardiomyopathies

Chapter 67 Echocardiographic Differentiation of Ischemic and Nonischemic Cardiomyopathy: Comparison with Other Noninvasive Modalities Chapter 68 Pericardial Disease Chapter 69 Three-Dimensional Echocardiographic Assessment in Pericardial Disorders Chapter 70 Echocardiographic Assessment of Cardiac Tumors and Masses

CHAPTER 60 Echocardiography in Ischemic Heart Disease Chetan Shenoy, Hamid Reza Salehi, Francesco F Faletra, Natesa G Pandian

Snapshot  DetecƟon of Ischemia  Role in Acute Coronary Syndromes  Mechanical ComplicaƟons of Myocardial InfarcƟon  Role of Echocardiography in Chronic Ischemic

 Novel Echocardiography Techniques in Ischemic

Heart Disease  Future

Cardiomyopathy

INTRODUCTION Coronary artery disease (CAD) is the leading cause of death for both men and women in the United States. Each year, an estimated 785,000 Americans will have a new coronary event, and nearly 470,000 will have a recurrent attack.1 It is estimated that an additional 195,000 silent first myocardial infarctions (MIs) occur each year.1 Approximately every 25 seconds, an American will have a coronary event, and approximately every minute, someone will die of one.1 Noninvasive diagnosis and evaluation of the effects of CAD are important in risk stratification and guides disease management. Since the 1980s, echocardiography has been the mainstay of cardiac imaging in the field of noninvasive evaluation of CAD.2 Echocardiography has a multifaceted role in ischemic heart disease.2 It can be used for the noninvasive detection of chronic ischemia, acute coronary syndrome (ACS), complications of ACS, and consequences of ischemic heart disease. The role of echocardiography in ischemic heart disease is well established, time-tested, and supported by extensive literature. Advances in echocardiographic

imaging technology such as tissue harmonic imaging and contrast echocardiography have significantly improved the accuracy and reliability of the modality in ischemic heart disease. In this chapter, we will discuss established as well as novel and emerging applications of echocardiography in ischemic heart disease.

DETECTION OF ISCHEMIA Stress echocardiography is commonly used for the detection of chronic ischemia in patients with known or suspected ischemic heart disease.3–6 Stress echocardiography can be performed either as an exercise test or as a pharmacological stress test. For patients who are capable of performing an exercise test, exercise stress rather than pharmacological stress is recommended, as the exercise capacity is a reliable predictor of outcomes. While either treadmill or bicycle exercise may be used for exercise stress, the treadmill is widely used in the United States.3–7 Symptom-limited exercise according to a standardized protocol in which the workload is gradually

1290


increased in stages is performed.3–5 The Bruce protocol is most commonly used for treadmill exercise echocardiography in the United States. Imaging is performed at rest and immediately after cessation of exercise.3–5 Exercise stress echocardiography provides valuable information for detection of ischemic heart disease and assessment of valvular heart disease (Fig. 60.1). Pharmacological stress testing is performed in patients who cannot exercise.5,6 Commonly used agents for pharmacological stress echocardiography include dobutamine and vasodilators. Although vasodilators may have advantages for assessment of myocardial perfusion, dobutamine is preferred when the test is based on assessment of regional wall motion.8 The standard for dobutamine stress testing is a graded dobutamine infusion starting at 5 μg/kg/min and increasing at 3-minutes intervals to 10, 20, 30 and 40 μg/kg/min.8 The low-dose stages allow detection of viability and ischemia in segments with abnormal function at rest, even when assessment of viability is not the primary objective of the test.8 Endpoints of a dobutamine stress echocardiography study are achievement of target heart rate (defined as 85% of the age-predicted maximum heart rate), new or worsening wall-motion abnormalities, significant arrhythmias, hypotension, severe hypertension, and intolerable symptoms.6,8 Atropine, in divided doses of 0.25 to 0.5 mg to a total of 2.0 mg, could be used as needed to achieve the target heart rate.8 Atropine increases the

sensitivity of dobutamine echocardiography in patients receiving -blockers and in those with single-vessel disease8 (Fig. 60.2). Both dobutamine and exercise echocardiography result in a marked increase of heart rate. The increase in blood pressure is much less with dobutamine compared with exercise. With both techniques, the induction of ischemia is related to an increase in myocardial oxygen demand. Vasodilator stress testing may be performed with adenosine or dipyridamole.6 Atropine is routinely used with vasodilator stress to enhance test sensitivity. The addition of handgrip at peak infusion enhances sensitivity. Vasodilator stress echocardiography usually produces a mild-to-moderate increase in heart rate and a mild decrease in blood pressure. While adenosine stress is used to assess myocardial perfusion with contrast echocardiography, it has not been widely used as a clinical tool.6 Interpretation of stress echocardiographic images involves visual assessment of endocardial excursion and wall thickening.6 Either a 16- or 17-segment model of the left ventricle (LV) may be used.6 Function in each segment is graded at rest and with stress as normal or hyperdynamic, hypokinetic, akinetic, dyskinetic, or aneurysmal.6 Images from low or intermediate stages of dobutamine infusion should be compared with peak stress images to maximize the sensitivity for detection of coronary disease6 (Fig. 60.2).

Fig. 60.1: Example of an exercise stress echocardiogram using contrast, demonstrating anterior wall ischemia (arrows). Upper panels—rest, lower panels—stress. Left panels—diastolic frames, right panels—systolic frame.

Fig. 60.2: Example of a dobutamine exercise stress echocardiogram, demonstrating inferior wall ischemia (arrows). Upper panels—rest, lower panels—stress. Left panels—diastolic frames, right panels—systolic frame.

Chapter 60: Echocardiography in Ischemic Heart Disease

A normal stress echocardiogram is defined as normal LV wall motion at rest and with stress.6 Abnormal study findings include those with fixed wall-motion abnormalities (i.e. resting wall-motion abnormalities, unchanged with stress, which most often represent regions of prior infarction), or new or worsening wallmotion abnormalities indicative of ischemia6 (Figs 60.1 and 60.2). In addition to the evaluation of segmental function, the global response of the LV to stress should be assessed. Stress-induced changes in LV shape, cavity size, and global contractility are also indicators of the presence or absence of ischemia and may indicate multivessel disease.6 The total amount of myocardium in jeopardy predicts risk, and prolonged persistence of systolic wallthickening abnormality may also identify severe CAD. Stress echocardiography can also predict the presence of myocardial hibernation when wall-motion abnormalities at rest improve or resolve with stress.6 Based on pooled data, stress echocardiography has an average sensitivity of 88% and an average specificity of 83% for the detection of coronary artery stenosis (generally >50% diameter stenosis by angiography).6 Studies comparing the accuracy of nuclear perfusion imaging and stress echocardiography in the same patient population have shown that the tests have similar sensitivities for the detection of CAD, but stress echocardiography has higher specificity. In a pooled analysis of 18 studies in 1,304 patients who underwent exercise or pharmacological stress echocardiography in conjunction with thallium- or technetium-labeled radioisotope imaging, sensitivity and specificity were 80 and 86% for echocardiography, and 84 and 77% for myocardial perfusion imaging, respectively.6 The relatively high specificity of stress echocardiography contributes to its use as a cost-effective diagnostic method. False-negative stress echocardiography studies result primarily from suboptimal stress. They are more common in patients with single-vessel disease or disease of the left circumflex artery because of the smaller amount of myocardium supplied by the left circumflex coronary artery, in patients with a small LV cavity and increased relative wall thickness, and in patients with significant aortic or mitral regurgitation (MR) leading to a hyperdynamic LV.6 False-positive stress echocardiography studies can be seen in patients with coronary artery spasm or in patients with decreased myocardial perfusion reserve in patients with LV hypertrophy, syndrome X, diabetes mellitus, myocarditis, and idiopathic cardiomyopathy.6 Stress-induced

1291

wall-motion abnormalities may also be seen in patients with hypertension or underlying cardiomyopathy, in the absence of ischemia. Finally, tethering of LV myocardium due to patients with significant mitral annular calcification or prior mitral valve replacement could lead to a reduction in motion of adjacent basal inferior and basal inferoseptal segments and result in false-positive stress studies.6 A normal stress echocardiogram is associated with an annual mortality risk of 0.4 to 0.9%, equivalent to that of an age- and sex-matched population, based on a total of 9,000 patients; thus, in patients with suspected CAD, a normal stress echocardiogram confers an excellent prognosis and coronary angiography can safely be avoided.6 With an abnormal stress echocardiogram, the risk of future mortality is directly related to the extent of the wall-motion abnormalities. Patients with extensive stress-induced abnormalities in a multivessel distribution are at a high risk of mortality and cardiac events. Variables on a stress echocardiogram that are associated with adverse outcomes include baseline LV dysfunction, wall-motion abnormalities in multivessel distribution, extensive ischemia, location of wall-motion abnormalities in left anterior descending coronary artery distribution, poor ejection fraction (EF) response or failure to reduce end-systolic volume with exercise, a low ischemic threshold and LV hypertrophy.6

Myocardial Contrast Stress Echocardiography Development of ultrasound contrast agents containing microbubbles that mimic red blood cell rheology, now allows simultaneous assessment of both function and perfusion via myocardial perfusion imaging, making it a unique technique for the assessment of CAD.9,10 Contrast stress echocardiography allows enhanced assessment of wall motion both at rest and during stress by improving visualization of the endocardial border, by improving the confidence in wall-motion assessment, and by reducing the number of uninterpretable images. Thus, by increasing the accuracy of wall-motion assessment, contrast echocardiography enhances the diagnostic value of stress echocardiography for the detection of CAD9,10 (Fig. 60.1). The onset of ischemic wall-motion abnormalities is preceded by development of regional disparities in coronary perfusion that can be assessed by contrast agents. Contrast echocardiography can, therefore, be employed

1292


Echocardiography today plays an essential role in the diagnosis of ACSs and their related complications.11,12 In patients presenting to the emergency room with chest pain suggestive of an ACS but with negative biomarkers and a nondiagnostic electrocardiogram (ECG), echocardiography plays an important role for diagnosis and prognostication.11,12 With a critical stenosis and interruption of blood flow in an epicardial coronary artery, the loss of myocardial function and development of clinical signs and symptoms proceed in a stepwise process referred to as the ischemic cascade. It starts with a defect in perfusion and progresses through abnormalities in left ventricular diastolic function, decreased myocardial contractility, increased left ventricular end-diastolic pressure, ST-segment changes, and occasionally, chest pain.13 This ischemic cascade forms the basis of the application of echocardiography

in the diagnosis of ACSs.13 Assessment of decreased myocardial contractility as noted by resting wall-motion abnormalities is the primary technique used in patients with ACS, while other less established techniques include assessment of diastolic dysfunction, and assessment of myocardial perfusion using contrast echocardiography.14 Stress echocardiography is the other important technique used in these patients.11,12 With unstable angina, the duration of ischemia and consequently the wall-motion abnormalities may be short-lived. Hence, assessment of wall-motion abnormality in patients with suspected ACS should be performed early after the onset of symptoms; normal wall motion in a patient with a normal ECG and without chest pain does not exclude an ACS. Conversely, if the patient has ischemic chest pain, a normal or equivocal ECG, and no regional wall-motion abnormalities on resting echocardiography during or immediately after the acute episode, the presence of acute ischemia is unlikely. The sensitivity of echocardiography in detection of ACS via resting wall-motion abnormalities is 90 to 95% with a negative predictive value of 90%15,16 (Figs 60.3 to 60.5). After an ACS has been diagnosed, echocardiographic assessment of wall motion aids in the assessment of site and severity of the acute CAD. The site of the myocardial insult and consequently, the infarct-related coronary artery, can be readily identified and the extent of the subendocardial damage determines the degree of wallthickening that takes place in the affected segments. Mild hypokinesis suggests only a small amount of myocardial damage affecting a small part of the endocardium.

A

B

for the detection of myocardial perfusion and several studies have demonstrated the clinical effectiveness of this technique for the detection of CAD.9,10 Similar to stress echocardiography without myocardial contrast, completely normal perfusion during myocardial contrast stress echocardiography is very reassuring with a <1% annual risk of adverse outcomes, while abnormal perfusion accompanied by wall-motion abnormalities identifies very high-risk patients with an approximately 15% annual event rate.9,10

ROLE IN ACUTE CORONARY SYNDROMES

Figs 60.3A and B: Example of a wall motion abnormality in the mid-distal anteroseptum in a parasternal three-chamber view (arrows). (A) Diastolic frame; (B) Systolic frame.


A

1293

B

Figs 60.4A and B: Example of a wall motion abnormality in the mid inferoseptum and inferior walls in a short-axis view (arrows). (A) Diastolic frame, (B) Systolic frame.

A

B

Figs 60.5A and B: Example of a wall motion abnormality in the mid-distal lateral wall in an apical four-chamber view (arrows). (A) Diastolic frame, (B) Systolic frame.

Severe hypokinesis is unusual in patients with small, nontransmural infarctions. However, it could occur in the presence of myocardial stunning overlying a small infarction. It is not uncommon for segments adjacent to the ischemic ones to become hypokinetic due to factors such as tethering. Therefore, wall-motion abnormalities following acute ischemia may be due to myocardial necrosis, stunned or hibernating myocardium, or more commonly, combinations of these factors.15 Echocardiography also provides useful prognostic information for identification of patients at risk of future cardiovascular events after an ACS. These data are based on assessment of global LV systolic function.15

Global LV systolic function in patients with ACS may be assessed through either wall-motion scoring or calculation of global LV ejection fraction (LVEF). Wallmotion scoring analysis assigns a numeric value to the degree of contractile dysfunction in each LV segment and a wall motion score index can be derived from the sum of individual segment scores divided by the number of evaluated segments. The wall-motion score index been shown to be an important prognostic indicator in patients with CAD. There are extensive data showing that LVEF is one of the most powerful predictors of adverse outcomes including mortality in patients with LV systolic dysfunction of any

1294


cause including ischemic heart disease. LVEF is the single most powerful predictor of mortality and the risk for lifethreatening ventricular arrhythmias after MI. After resolution and management of an ACS, the residual LVEF is important for treatment from both medical and device therapies standpoint. Even after acute treatment and clinical stabilization of heart failure, LVEF has a strong and close relationship with survival in patients with decreased LVEF. The right coronary artery also commonly supplies the right ventricle (RV), which may also be involved in the MI. This has important implications in the acute management of patients; so assessment of the RV in patients with ACS is important to assess the degree of RV dysfunction.15 In patients with clinically suspected RV MI, echocardiography showing RV cavity enlargement and impaired RV free wall motion confirms the diagnosis of RV MI and helps exclude other possibilities for the clinical presentation, such as pericardial tamponade, which may present with the same clinical picture. Echocardiography can be misleading for the diagnosis of RV MI in patients with chronic pulmonary disease, such as chronic obstructive lung disease or significant pulmonary arterial hypertension, or acute pulmonary disease such as pulmonary embolism.

MECHANICAL COMPLICATIONS OF MYOCARDIAL INFARCTION Echocardiography is the primary diagnostic tool for detection of potentially life-threatening complications of acute MI.17,18 Portability, immediate availability, quick imaging, and the detailed information it provides both on cardiac function and blood flow are critical in the management of patients with known or suspected mechanical complications of MI. By helping in diagnosis and decision-making in these often critically ill patients, echocardiography can be life-saving.17,18 After the diagnosis of a mechanical complication has been made, echocardiography could also be used to guide the intraoperative management (usually with transesophageal echocardiography) and in assessing the outcome of complicated surgeries and therapeutic procedures.17,18

Rupture of Left Ventricular Free Wall Rupture of the LV free wall is the most common form of myocardial rupture and the cause of death in

approximately 10% of the patients who die after an acute MI.19,20 It occurs within the first 24 hours in about half the patients and within a week in 85%. Any wall—anterior, lateral, or inferior—can be involved. In up to 40% of cases, ruptures have a subacute course with ongoing myocardial tearing and bleeding into the pericardial space. A pseudoaneurysm is a manifestation of a subacute tear that is spontaneously sealed. Since; sudden death is often a presentation of complete rupture of the LV free wall, echocardiography has a bigger role in diagnosis of patients with subacute free wall rupture.19,20 These patients often have pericardial effusions secondary to hemopericardium, layered thrombus in the pericardial space, or cardiac tamponade with hemodynamic instability.19,20 A finding of a pericardial effusion of 5 mm during diastole and layered thrombus within the pericardial space are highly sensitive for the detection of free wall rupture. The ruptured site is seldom detected with two-dimensional (2D) echocardiography; however, this may be possible with color-flow Doppler.19,20 Contrast echocardiography may be helpful in establishing the diagnosis of free wall rupture in patients with a subacute presentation.21 Passage of contrast agent into the pericardial space after an intravenous injection confirms a connection between the heart and the pericardial space, while lack of contrast in the pericardial space helps exclude a LV free wall rupture.21

Left Ventricular Pseudoaneurysm An LV pseudoaneurysm is formed when a subacute tear in the LV wall is spontaneously sealed and contained by adherent pericardium or scar tissue22 (Figs 60.6A and B). As opposed to a true LV aneurysm (Figs 60.6 and 60.7) where the outer layer consists of thinned, necrotic, or scarred myocardium, myocardium is not present in the external layer of the pseudoaneurysm.22 A true aneurysm and a pseudoaneurysm carry greatly different implications since a true LV aneurysm rarely ruptures, while there is a high risk of rupture with a pseudoaneurysm.22 Surgical repair is indicated in most cases of pseudoaneurysm, while it is not indicated in most cases of true LV aneurysm. Therefore, echocardiography plays a crucial role not only in the identification of a LV pseudoaneurysm, but also for the confirmation of the absence of a true LV aneurysm.22 LV pseudoaneurysm is often detected when echocardiography is performed routinely post MI or for indications of congestive heart failure or an embolic


A

1295

B

Figs 60.6A and B: Example of a left ventricular aneurysm (arrow in Fig. A) and a left ventricular pseudoaneurysm (arrow in Fig. B). The asterisk in the right image shows the narrow neck.

Fig. 60.7: Example of a left ventricular apical aneurysm (arrows).

event.23 A sharp discontinuity of the endocardial border at the communication site of the pseudoaneurysm with the LV cavity, a saccular or globular contour of the pseudoaneurysm, and a relatively narrow neck at the communication site of the pseudoaneurysm with the LV cavity are often seen on echocardiography23 (Figs 60.6A and B). Careful examination and use of off-plane imaging may sometimes be required for the identification and complete characterization of the site of rupture. A thrombus may be visualized within the pseudoaneurysm cavity.23 Color Doppler can also aid in the detection of LV pseudoaneurysm and the characteristic finding is the bidirectional flow between the cavities of the LV and the pseudoaneurysm.23 A jet of bidirectional flow helps distinguish a LV pseudoaneurysm from a pericardial effusion or true aneurysm. The use of contrast agents may also help in the diagnosis of LV pseudoaneurysm.24 Intravenous contrast agents can clearly demonstrate the narrow neck and the communication between the cavities of the LV and the pseudoaneurysm.24

the anterior two-third being supplied by branches of the left anterior descending coronary artery and the posterior third by the posterior descending artery of either the right or circumflex coronary arteries.26 The timing of occurrence of ventricular septal rupture varies depending on whether the patient was reperfused or not. It occurs within the first week after MI in patients who did not receive reperfusion therapy, with peaks on the first day and on days 3, 4 and 5 after the MI. In patients treated with thrombolytic therapy, most ruptures occur within the first 2 days.26 Septal ruptures can be discrete with a direct throughand-through communication at the same level on both sides of the septum or be complex and irregular with serpinginous tracts. In anterior MIs, septal ruptures are usually apical and discrete, whereas in inferior MIs they are more commonly in the basal inferoposterior septum and more often complex.26 The ventricular septal defect can be visualized with 2D echocardiography alone in approximately 50% of patients18 (Figs 60.8 to 60.10 and Movie clip 60.1). Multiple imaging planes should be used and careful off-plane imaging may be required to visualize the ventricular septal defect. Nevertheless, 2D echocardiography may not detect small defects and therefore, color Doppler imaging is crucial when looking for a ventricular septal rupture. Typically seen are turbulent transseptal flow and systolic flow disturbance within the RV. In cases of complex defects, color Doppler imaging may demonstrate multiple holes or serpinginous tracts between the LV and the RV. Using

Ventricular Septal Rupture Ventricular septal rupture most commonly occurs after a transmural MI and is more frequent in acute anterior infarction, extensive infarction, right ventricular infarction, and in total occlusion of the infarct-related artery.25,26 This complication of MI is rare (incidence of 0.2–0.3%), due to the dual blood supply of the ventricular septum, with

1296


Fig. 60.8: Example of a postmyocardial infarction ventricular septal rupture with flow across the defect (arrows).

A

B

Figs 60.9A and B: Example of a postmyocardial infarction ventricular septal rupture with flow across the defect (arrows).

A

B

Figs 60.10A and B: Example of a postmyocardial infarction ventricular septal rupture (asterisk); 2D image (A) and 3D image (B).


1297

Papillary muscle rupture is the rarest mechanical complications of MI.17,18 The posteromedial papillary muscle is the most affected, having its blood supply only from the posterior descending coronary artery as opposed to the anterolateral papillary muscle that has a dual blood supply, both from the diagonal branch and the left circumflex artery. Because of its single-vessel blood supply, the posteromedial papillary muscle is 6 to 12 times more vulnerable to rupture than the anterolateral papillary

muscle. The most frequent site of MI is, therefore, the inferolateral wall.17,18 Often, the infarct size and expansion are relatively small, and up to half of the patients have single-vessel coronary disease, with many of them having had their first MI. This complication generally occurs 2 to 7 days after an MI and is responsible for approximately 5% of acute MI-associated mortality. Mortality is very high if left untreated. About half die within the first day of rupture and 90% within a week without surgical therapy. Therefore, echocardiography is crucial for an early and accurate diagnosis17,18 (Figs 60.11A and B and Movie clip 60.2). Typical findings on 2D echocardiography include a flail mitral valve leaflet and often a mobile mass seen attached to the chordae and prolapsing into the left atrium during systole, which is the head of the ruptured papillary muscle. Partial rupture of a papillary muscle, defined as a partial disconnection of the base of the papillary muscle or rupture of one of several heads is seen more often than complete rupture.17,18 In such cases, 2D echocardiography shows a thin and excessively mobile papillary muscle. The LV systolic function is often hyperdynamic. Color Doppler imaging usually reveals severe MR, and the direction of the regurgitation jet points to the affected mitral leaflet: posteriorly directed regurgitation jet in flail anterior leaflet and anteriorly directed jet in posterior flail leaflet. If both leaflets are involved, the jet is centrally directed. The severity of MR may be underestimated with eccentric regurgitant jets, and a TEE may provide incremental data in such cases.17,18

A

B

color Doppler imaging, the ventricular septal defect can be characterized in terms of the location and the size of the defect. The left to right jet seen on color Doppler is typically pansystolic. In about half the patients, an aneurysm of the ventricular septum can be seen protruding into the RV. Similarly, in about half the patients, hyperkinetic LV segments can be seen opposite the segment of the septal defect. Decreased RV systolic function is not uncommon and significant tricuspid regurgitation is frequently noted secondary to high RV pressure.18,27 Transesophageal echocardiography (TEE) is frequently performed to assess for mechanical complications in a critically ill or acutely decompensated patient following an MI.27 TEE may provide better imaging compared to transthoracic echocardiography and may provide improved visualization of the morphology, number, location, and size of the ventricular septal defect(s), and consequently better guide management decisions.27

Papillary Muscle Rupture

Figs 60.11A and B: Examples of papillary muscle rupture (arrows) in two different patients.

1298


Left Ventricular Aneurysm A true LV aneurysm is a saccular protrusion or a bulge of the LV wall during both systole and diastole, demonstrating dyskinetic or akinetic motion28 (Fig. 60.6). As opposed to a LV pseudoaneurysm where there is no myocardium in the external layer of the pseudoaneurysm, the outer layer of a true LV aneurysm consists of thinned, necrotic, or scarred myocardium.17,18,28 LV aneurysms are frequent complications of acute MI, and may be a cause of heart failure, LV thrombus formation predisposing to the risks of systemic embolization, and ventricular arrhythmias. LV aneurysms occur from infarct expansion and adverse remodeling of the involved segment, usually the apex, which is the thinnest segment of the normal LV myocardium.28 Echocardiography has excellent sensitivity and specificity for the detection of LV aneurysms after MI.17,18,28 LV thrombus formation occurs almost exclusively in the akinetic or dyskinetic apex with or without aneurysm formation.17,18 Most thrombi are formed within 48 hours to 1 week of the MI. Late formation of thrombus may be seen in patients with severe congestive heart failure and deteriorating LV systolic function. Chronic LV thrombus, occurring 3 months or more after infarction, is seen with a true LV aneurysm and nearly half of all patients with a true LV aneurysm have a LV thrombus. In spite of its high prevalence, chronic mural thrombi are likely to be organized and therefore, rarely embolize. Acute thrombi within an aneurysm are likely to be mobile and projecting

A

into the lumen, and therefore have a greater risk of embolization17,18 (Figs 60.12A and B). Echocardiography is fairly sensitive and specific for the detection of LV thrombus.29 Reasons for false identification of LV thrombus include trabeculations, aberrant bands, papillary muscle, tumors, or noise and artifacts that are mistaken for LV thrombus. Contrast agents improve visualization of LV thrombi and the sensitivity and specificity of echocardiography for the detection of LV thrombus.24

ROLE OF ECHOCARDIOGRAPHY IN CHRONIC ISCHEMIC CARDIOMYOPATHY Chronic long-standing CAD, with or without infarction, may result in progressive deterioration of LV function and other accompanying pathology such as ischemic MR, increased left atrial pressure, and so on. Echocardiography is very valuable in the evaluation of chronic ischemic cardiomyopathy and associated conditions30 (Figs 60.13A and B). The assessment of LV systolic function and particularly regional wall motion is primarily used for the diagnosis of ischemic cardiomyopathy, determination of the severity, and prognostication of patients with CAD.30 Ischemic cardiomyopathy is diagnosed on the basis of LV systolic dysfunction, typically with regional wallmotion abnormalities. There are several possible reasons for LV systolic dysfunction in patients with chronic ischemic heart disease.

B

Figs 60.12A and B: Example of central mitral regurgitation due to ischemic cardiomyopathy [2D image (A) and color Doppler image (B)].


A

1299

B

Figs 60.13A and B: Examples of a left ventricular apical thrombus (arrows) in two different patients, one without (A) and one with contrast (B).

During an acute MI, the acute occlusion of blood flow in an epicardial coronary artery leads to a rapid reduction in resting myocardial blood flow and progressive death of myocardium within the perfusion territory, starting from the subendocardium and extending out to the subepicardium in a wavefront phenomenon, as described in 1979 by Reimer and Jennings.31 When blood flow is restored, the myocardial necrosis is halted and some of the acutely ischemic myocardium at risk is salvaged. The extent of myocardium salvaged depends on the promptness and efficacy of the revascularization therapy. LV systolic function is affected soon after decrease in resting myocardial blood flow and persists after the acute MI.31 In the acute and subacute stages of a MI, the dead myocardium is necrosed and causes segmental wallmotion abnormalities. The necrosed myocardium gradually thins and reorganizes into scar tissue or fibrosis over weeks to months. Thus, patients with a prior MI and wallmotion abnormalities have myocardial fibrosis and scar tissue leading to contractile dysfunction. After an acute MI, wall motion may not return to normal for several hours to weeks after blood flow has been restored and the MI has completed. The LV systolic dysfunction in an area of uninfarcted myocardium is called “myocardial stunning” and is reversible.32 In patients with chronic CAD, increasing reduction in myocardial blood flow due to the progression of CAD may result in down-regulation of myocardial contractile function with preserved metabolic activity. This is also reversible and this area of the myocardium

is termed “hibernating myocardium.”33 When blood flow to the hibernating myocardium is restored through revascularization of the stenotic artery, contractile function returns gradually. Systolic dysfunction in chronic CAD may also occur due to myocardial stunning resulting from repeated ischemic episodes occurring at rest (vasospasm) or during increased myocardial oxygen demand such as exercise.33 Therefore, wall-motion abnormalities in patients with ischemic cardiomyopathy may be due to multiple reasons—myocardial necrosis, myocardial fibrosis, stunned or hibernating myocardium, and is likely due to combinations of these factors. Determining the exact cause of wall-motion abnormalities in patients with ischemic cardiomyopathy carries significant implications for management decisions. For example, hibernating myocardium may warrant revascularization, as opposed to fibrotic and scarred myocardium, which may not respond as well to revascularization.33 Determination of LV fibrosis on rest echocardiography is based on wall thickness and echobrightness of the segments. Segments thinner than 5 mm in diastole have been traditionally felt to be nonviable; there has been a long-standing thought that the likelihood of recovery of contractility in such thinned segments is very low.34 However, recent data using cardiac magnetic resonance imaging (CMR) have challenged this paradigm and demonstrated that regional wall thinning could be associated with limited scar burden in approximately 18% of patients and associated with improved contractility and resolution of wall thinning after revascularization.35

1300


Myocardial contrast echocardiography permits the assessment and quantification of myocardial blood flow, both at rest and during hyperemia.24,36 The basic pathophysiological principle behind this technique is that viable myocardium has an intact microcirculation, whereas infarcted, nonviable tissue loses this microvasculature. Myocardial contrast echocardiography allows measurement of myocardial blood flow and blood volume, and thus provides a direct evaluation of microvascular integrity of the dysfunctional segments, and therefore, viability and the likelihood of functional recovery after revascularization.24 Contractile reserve and therefore viability can be assessed using provocative stimuli such as exercise, nitroglycerin, dipyridamole, postextrasystolic potentiation, and catecholamine (e.g. isoprenaline, adrenaline, dopamine, or dobutamine) infusion in conjunction with echocardiography. Of these options, dobutamine stress echocardiography is the most accepted and widely performed of these techniques. Its diagnostic and prognostic value in the detection of myocardial viability has been well established.8 Dobutamine at low doses of <10 μg/kg/min demonstrates a relatively more potent inotropic effect than chronotropic effect, allowing stimulation of myocardial contractility before significant increases in heart rate, and ischemia, occur. This is useful for the assessment of contractile reserve. Dobutamine at higher doses leads to both inotropic and chronotropic stimulation, resulting in increased cardiac output, myocardial oxygen consumption, and ischemia in the presence of significant CAD.8,37 The protocol for assessment of viability by dobutamine starts with two low-dose stages (5 and 10 μg/kg/min), with each stage lasting 3 minutes, and the dose is increased in 10 μg/kg/min increments to a maximum dose of 50 μg/kg/ min. Atropine may be given if the target heart rate is not achieved. The test is terminated when the patient achieves 85% of the age-predicted maximum heart rate, or clinical or echocardiographic evidence of ischemia occurs. Viable segments will demonstrate improvement of contractility at doses of 5 or 10 μg/kg/min. Even when viability or contractile reserve is noted at a low dose, higher doses should be administered to observe a biphasic response, wherein there is hypokinesis and decreased contractility at high doses due to ischemia. The biphasic response has the best predictive value for prediction of improvement in LV

function following revascularization, with lower chances of functional recovery with revascularization when there is either no contractile improvement at either low or high dose, or sustained improvement with both low and high doses of dobutamine.8

Ventricular Function in Chronic Ischemic Heart Disease Assessment of Systolic Function Global LV systolic function in patients with ischemic cardiomyopathy may be assessed through either calculation of global LVEF or wall-motion scoring.38 Left ventricular EF is most commonly computed from echocardiography by using Simpson’s method of using systolic and diastolic volumes obtained from biplane planimetry of paired orthogonal long-axis apical views (Figs 60.14A and B). While quantitative techniques generally are more accurate, grading based on visual assessment is not inferior to other reference methods. In most echocardiography laboratories, the LVEF is determined by subjective visual assessment of a single experienced reader. There are extensive data showing that LVEF is one of the most powerful predictors of adverse outcomes including mortality in patients with LV systolic dysfunction of any cause including ischemic heart disease. LVEF is the single most powerful predictor of mortality and the risk for lifethreatening ventricular arrhythmias after MI. Wall-motion scoring analysis assigns a numeric value to the degree of contractile dysfunction in each LV segment and a wall motion score index can be derived from the sum of individual segment scores divided by the number of evaluated segments.38 Doppler echocardiography can also provide useful noninvasive estimation of left ventricular stroke volume and cardiac output.

Assessment of Diastolic Function By definition, all patients with systolic dysfunction have varying degrees of diastolic dysfunction. Assessment of diastolic function is more useful in patients with normal systolic function but clinical features of heart failure or those at risk for heart failure, in whom diastolic dysfunction is clinically silent.39


A

1301

B

Figs 60.14A and B: Example of Simpson’s method of quantification of LV ejection fraction. Diastolic frame (A) and systolic frame (B). (LV: Left ventricle).

Details of assessment of diastolic function are beyond the scope of this chapter and are discussed elsewhere in this textbook. In patients with normal LVEFs, LV filling pressures can be calculated using measures of diastolic function. An E/e' ratio (E = peak early passive diastolic transmitral flow recorded by pulsed wave Doppler imaging and e' = peak mitral annular velocity recorded by tissue Doppler imaging) of ≤8 identifies patients with normal LV filling pressures, whereas a ratio ≥13 indicates increased LV filling pressures.39 When the ratio is between 9 and 13, other measurements are useful. An Ar – A duration (Ar = duration of the atrial reversal waveform on pulmonary venous flow recorded by pulsed wave Doppler imaging and A duration = duration of late diastolic wave across the mitral valve recorded by pulsed wave Doppler imaging) ≥ 30 ms, a change in E/A ratio (E = peak early passive diastolic transmitral flow recorded by pulsed wave Doppler imaging and A = peak late diastolic transmitral flow recorded by pulsed wave Doppler imaging) with the Valsalva maneuver of ≥ 0.5, IVRT/TE – e' [IVRT = isovolumetric relaxation time, or the time interval between aortic valve closure and mitral valve opening as recorded by pulsed wave Doppler imaging and TE – e' = the time interval between the QRS complex and the onset of mitral E wave (TE) on pulsed wave Doppler imaging subtracted from the time interval between the QRS complex and e' onset on tissue Doppler imaging] < 2, pulmonary artery systolic pressure ≥ 35 mm Hg (in the absence of pulmonary disease), and maximal left atrial volume ≥ 34 mL/m2 are all indicative of increased LV filling pressures.39

In patients with decreased LVEFs, the mitral inflow pattern can be used to estimate filling pressures with reasonable accuracy. Changes in the inflow pattern can be used to track filling pressures in response to medical therapy. In patients with impaired relaxation patterns and peak E velocities < 50 cm/s, LV filling pressures are usually normal. With restrictive filling, mean LA pressure is increased.39 The use of additional Doppler parameters is recommended in patients with E/A ratios of ≥ 1 to < 2. A change in E/A ratio with the Valsalva maneuver of ≥ 0.5, a systolic peak velocity/diastolic peak velocity ratio in pulmonary venous flow < 1, Ar – A duration ≥ 30 ms, E/e = (using average e) ≥ 15, IVRT/TE – e' > 2, and pulmonary artery systolic pressure ≥ 35 mm Hg (in the absence of pulmonary disease) are suggestive of the presence of increased filling pressures.39

NOVEL ECHOCARDIOGRAPHY TECHNIQUES IN ISCHEMIC HEART DISEASE Three-Dimensional Echocardiography While 3D echocardiography (3DE) has potential roles in assessment of ischemia by stress testing, wallmotion abnormalities, left ventricular aneurysm, and pseudoaneurysm, other complications of MI, the primary application in patients with ischemic heart disease, is in the quantification of cardiac chamber volumes, function, and LV mass.40–42

1302


LV chamber and mass quantification have been studied extensively using 3DE and have been shown to be more accurate and reproducible than 2D echocardiography techniques. A distinct advantage of 3DE over 2D echocardiography is the ability to manipulate the plane to align the true long axis and minor axis of the LV, thereby avoiding foreshortening and oblique imaging planes.40–42 LV volume assessment by real time 3DE has been demonstrated to be rapid, accurate, reproducible, and superior to conventional 2D methods.40–42 The LV volumes can be segmented, which allows for regional LV function assessment. LV volume and mass obtained by real time 3DE correlate well with those obtained with CMR or radionuclide imaging. Similarly, real time 3DE allows improved accuracy of RV size and function assessment. Use of real time 3DE in stress echocardiography decreases imaging time (standard views can be obtained with only 1 or 2 image acquisitions) with accuracy comparable to 2D stress imaging.40–42 Use of ultrasound contrast agents with 3DE potentially improves quantification of LV volumes and EF. Another evolving application of contrast 3DE is in the evaluation of myocardial perfusion.43 Contrast 3DE offers the ability to image the entire LV and to quantify the full extent of hypoperfused myocardium.43 Thus, 3DE is complementary to 2D imaging and can be used to improve assessment of cardiac function and morphology in patients with ischemic heart disease. Further technological developments will lead to improvements and will contribute to more practical applications of 3DE in this group of patients.40–43

Speckle-Tracking Echocardiography Strain imaging potentially has incremental value in the ability of echocardiography to detect and objectively qualify ischemia and infarction.44,45 Speckle-tracking echocardiography as a new noninvasive imaging technique can be helpful for an objective and quantitative evaluation of global and regional myocardial function. In contrast to tissue Doppler imaging, it works almost independently from the angle of insonation and from cardiac translational movements. This technique is potentially a better tool to detect myocardial ischemic segments and also differentiate active contraction from passive motion such as passive expansion, and recoil and tethering from adjacent segments.44–46

Myocardial Ischemia The subendocardium is the most vulnerable area to the effects of hypoperfusion and ischemia; so, LV longitudinal mechanics (mainly generated by subendocardium) as the most sensitive parameter may be attenuated in patients with CAD even at rest. Circumferential strain and twist may remain normal or show exaggerated compensation for preserving LV systolic performance. A lower longitudinal strain value in asymptomatic patients without wallmotion abnormalities can be a strong predictor of stable ischemic cardiomyopathy. Recently, postsystolic index has been proposed as an important quantitative marker for analysis of the ischemic myocardium. LV endocardial area change ratio by 3D speckle tracking coupled with both longitudinal and circumferential strain have proposed to assess induced acute myocardial ischemia in a sheep model.46

Myocardial Infarction Longitudinal strains are significantly reduced in patients with MI, proportionately within the area of infarction, and correlate closely with peak infarct mass and EF. While longitudinal strain has been used to detect MI, radial and circumferential strain values have been used to distinguish nontransmural infarction from transmural infarction47 (Figs 60.15 and 60.16). The pattern of postsystolic shortening peak strain after aortic valve closure has been also reported helpful. In some studies, longitudinal strain was related to peak levels of cardiac troponin T and the LV infarct size. It has also been shown that longitudinal strain correlates with the global and regional extent (transmurality) of scar tissue as evaluated by contrastenhanced MRI.47

Reperfusion Longitudinal strain (measured immediately after reperfusion therapy) has been suggested as an excellent predictor of LV remodeling and adverse events, such as congestive heart failure and death.45 When combined with wall-motion scoring, strain rate imaging offered incremental value over wall-motion scoring alone for prediction of functional recovery after revascularization.48

Myocardial Viability Strain imaging as an adjunct to low-dose dobutamine stress echocardiography has been suggested to assess


A

1303

B

Figs 60.15A and B: Polar map derived from speckle-tracking echocardiography showing longitudinal strain in different segments of two cases, (A) Normal subject (homogeneous yellow) and (B) A patient with a LAD lesion with lower (orange) and positive strain (blue) in the anteroseptal and septal segments.

A

B

Figs 60.16A and B: Speckle-tracking echocardiography demonstrating segmental longitudinal strain in a normal subject (A) and in a patient with hypokinesis and dyskinesis due to a LAD lesion (B).

myocardial viability.49 In addition, a favorable correlation between resting longitudinal LV strain and the extent of scarring by CMR imaging has been reported. Both myocardial velocity and deformation parameters have been analyzed at rest and during dobutamine stimulation to define the functional reserve.49 Although speckle tracking is regarded as a revolution in echocardiography, prospective clinical trials for the validation of this technique in large populations are still lacking. To date, strain rate has not replaced conventional gray-scale imaging in the assessment of regional LV function and the implementation of these new indices into routine clinical practice will need additional clinical and large-scale studies.44

FUTURE Despite the emergence of competing imaging modalities, echocardiography remains and will continue to be the primary imaging modality for patients with ischemic heart disease due to its portability, ease of use, safety, and technological advancements in terms of techniques and instrumentation such as tissue Doppler imaging, 3DE, speckle-tracking imaging, and contrast echocardiography. Future advances in technology and increased clinical data will lead to overcoming of current limitations and further increase the value of echocardiography in the everyday clinical use for patients with ischemic heart disease.

1304


REFERENCES 1. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics—2012 update: a report from the American Heart Association. Circulation. 2012;125(1):e2–220. 2. Gandy WH Jr, Nanda NC. Echocardiography in coronary artery disease. Curr Opin Cardiol. 1992;7(4):582–6. 3. Feigenbaum H. Stress echocardiography: an overview. Herz. 1991;16(5):347–54. 4. Feigenbaum H. The evolution of stress echocardiography. Cardiol Clin. 1999;17(3):443–6, vii. 5. Senior R, Monaghan M, Becher H, et al. British Society of echocardiography. Stress echocardiography for the diagnosis and risk stratification of patients with suspected or known coronary artery disease: a critical appraisal. Supported by the British Society of Echocardiography. Heart. 2005;91(4):427–36. 6. Pellikka PA, Nagueh SF, Elhendy AA, et al. American Society of Echocardiography. American Society of Echocardiography recommendations for performance, interpretation, and application of stress echocardiography. J Am Soc Echocardiogr. 2007;20(9):1021–41. 7. Sicari R, Nihoyannopoulos P, Evangelista A, et al. European Association of Echocardiography. Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC). Eur J Echocardiogr. 2008;9(4):415–37. 8. Ryan T, Williams R, Sawada SG. Dobutamine stress echocardiography. Am J Card Imaging. 1991;5(2):122–32. 9. Porter TR, Xie F. Myocardial perfusion imaging with contrast ultrasound. JACC Cardiovasc Imaging. 2010;3(2):176–87. 10. Chelliah RK, Senior R. Contrast echocardiography: an update. Curr Cardiol Rep. 2009;11(3):216–24. 11. Greaves SC. Role of echocardiography in acute coronary syndromes. Heart. 2002;88(4):419–25. 12. Autore C, Agati L, Piccininno M, et al. Role of echocardiography in acute chest pain syndrome. Am J Cardiol. 2000;86(4A):41G–42G. 13. Fuster V, Stein B, Ambrose JA, et al. Atherosclerotic plaque rupture and thrombosis. Evolving concepts. Circulation. 1990;82(3 Suppl):II47–59. 14. Ward RP, Lang RM. Myocardial contrast echocardiography in acute coronary syndromes. Curr Opin Cardiol. 2002; 17(5):455–63. 15. Sia YT, O’Meara E, Ducharme A. Role of echocardiography in acute myocardial infarction. Curr Heart Fail Rep. 2008;5(4):189–96. 16. Lewis WR. Echocardiography in the evaluation of patients in chest pain units. Cardiol Clin. 2005;23(4):531–9, vii. 17. Reeder GS. Identification and treatment of complications of myocardial infarction. Mayo Clin Proc. 1995;70(9):880–4. 18. Buda AJ. The role of echocardiography in the evaluation of mechanical complications of acute myocardial infarction. Circulation. 1991;84(3 Suppl):I109–21. 19. Figueras J, Cortadellas J, Soler-Soler J. Left ventricular free wall rupture: clinical presentation and management. Heart. 2000;83(5):499–504.

20. Mann JM, Roberts WC. Rupture of the left ventricular free wall during acute myocardial infarction: analysis of 138 necropsy patients and comparison with 50 necropsy patients with acute myocardial infarction without rupture. Am J Cardiol. 1988;62(13):847–59. 21. Mittle S, Makaryus AN, Mangion J. Role of contrast echocardiography in the assessment of myocardial rupture. Echocardiography. 2003;20(1):77–81. 22. Brown SL, Gropler RJ, Harris KM. Distinguishing left ventricular aneurysm from pseudoaneurysm. A review of the literature. Chest. 1997;111(5):1403–9. 23. Frances C, Romero A, Grady D. Left ventricular pseudoaneurysm. J Am Coll Cardiol. 1998;32(3):557–61. 24. Pandian NG. Clinical applications of contrast echocardiography. Eur J Echocardiogr. 2004;5(Suppl 2):S3–10. 25. Radford MJ, Johnson RA, Daggett WM Jr, et al. Ventricular septal rupture: a review of clinical and physiologic features and an analysis of survival. Circulation. 1981;64(3): 545–53. 26. Davis N, Sistino JJ. Review of ventricular rupture: key concepts and diagnostic tools for success. Perfusion. 2002;17(1):63–7. 27. Topaz O, Taylor AL. Interventricular septal rupture complicating acute myocardial infarction: from pathophysiologic features to the role of invasive and noninvasive diagnostic modalities in current management. Am J Med. 1992;93(6):683–8. 28. Friedman BM, Dunn MI. Postinfarction ventricular aneurysms. Clin Cardiol. 1995;18(9):505–11. 29. Keeley EC, Hillis LD. Left ventricular mural thrombus after acute myocardial infarction. Clin Cardiol. 1996;19(2): 83–6. 30. Chaudhry FA, Iskandrian AE. Assessing myocardial viability in ischemic cardiomyopathy. Echocardiography. 2005;22(1):57. 31. Reimer KA, Jennings RB. The “wavefront phenomenon” of myocardial ischemic cell death. II. Transmural progression of necrosis within the framework of ischemic bed size (myocardium at risk) and collateral flow. Lab Invest. 1979;40(6):633–44. 32. Bolli R. Basic and clinical aspects of myocardial stunning. Prog Cardiovasc Dis. 1998;40(6):477–516. 33. Castro PF, Bourge RC, Foster RE. Evaluation of hibernating myocardium in patients with ischemic heart disease. Am J Med. 1998;104(1):69–77. 34. Mazur W, Nagueh SF. Myocardial viability: recent developments in detection and clinical significance. Curr Opin Cardiol. 2001;16(5):277–81. 35. Shah DJ, Kim HW, James O, et al. Prevalence of regional myocardial thinning and relationship with myocardial scarring in patients with coronary artery disease. JAMA. 2013;309(9):909–18. 36. Nesser HJ, Morcerf F, Teupe C, et al. Myocardial perfusion imaging using contrast echocardiography. Herz. 2002 May; 27(3):217–26.


37. McLean DS, Anadiotis AV, Lerakis S. Role of echocardiography in the assessment of myocardial viability. Am J Med Sci. 2009;337(5):349–54. 38. Lang RM, Bierig M, Devereux RB, et al. Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 39. Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2009;22(2):107–33. 40. Pandian NG, Roelandt J, Nanda NC, et al. Dynamic threedimensional echocardiography: methods and clinical potential. Echocardiography. 1994;11(3):237–59. 41. Nanda NC, Miller AP. Real time three-dimensional echocardiography: specific indications and incremental value over traditional echocardiography. J Cardiol. 2006; 48(6):291–303.

1305

42. Hage FG, Nanda NC. Real-time three-dimensional echocardiography: a current view of what echocardiography can provide? Indian Heart J. 2009;61(2):146–55. 43. Burri MV, Gupta D, Kerber RE, et al. Review of novel clinical applications of advanced, real-time, 3-dimensional echocardiography. Transl Res. 2012;159(3):149–64. 44. Urbano-Moral JA, Patel AR, Maron MS, et al. Threedimensional speckle-tracking echocardiography: methodological aspects and clinical potential. Echocardiography. 2012;29(8):997–1010. 45. Mondillo S, Galderisi M, Mele D, et al. Speckle-tracking echocardiography: a new technique for assessing myocardial function. J Ultrasound Med. 2011;30(1):71–83. 46. Gorcsan J, Tanaka H. Are new myocardial tracking systems of three-dimensional strain a reality in daily clinical practice?. Rev Esp Cardiol. 2011;64(12):1082–9. 47. Geyer H, Caracciolo G, Abe H, et al. Assessment of myocardial mechanics using speckle tracking echocardiography: fundamentals and clinical applications. J Am Soc Echocardiogr. 2010;23(4):351–69; quiz 453. 48. Gorcsan J 3rd, Tanaka H. Echocardiographic assessment of myocardial strain. J Am Coll Cardiol. 2011;58(14):1401–13. 49. Gorcsan J 3rd. Echocardiographic strain imaging for myocardial viability: an improvement over visual assessment? Circulation. 2005;112(25):3820–22.

CHAPTER 61 Stress Echocardiography Azhar Supariwala, Siu-Sun Yao, Farooq A Chaudhry

Snapshot ¾¾ Fundamentals of Stress Echocardiography ¾¾ Types of Stress Echocardiography

INTRODUCTION Stress echocardiography was first introduced by Wann and coworkers with supine bicycle exercise,1 but the application was limited until the development of digital acquisition.2,3 Stress echocardiography is now routinely used in the diagnosis, risk stratification, and prognosis of patients with known or suspected coronary artery disease (CAD).4,5 In recent years, there have been further advances in the application of stress echocardiography, including the evaluation of valvular and anatomic abnormalities of the heart, hemodynamics, myocardial perfusion, quantitation of wall motion abnormality with speckle tracking, and three-dimensional (3D) imaging.

FUNDAMENTALS OF STRESS ECHOCARDIOGRAPHY The most common application of stress echocardiography is the detection of flow limiting stenosis. The use of stress echocardiography to diagnose flow-limiting CAD is based on a sequence of events known as the ischemic

¾¾ Interpretation of Stress Echocardiography ¾¾ Stress Echocardiography: Future Directions

cascade6 (Fig. 61.1). Normal coronary arteries adapt to stress by coronary vasodilatation (coronary flow reserve) to maintain flow to meet the increased oxygen demand. In the presence of a flow-limiting coronary stenosis, coronary flow reserve is impaired resulting in ischemic cascade including wall motion abnormality. Abnormalities of regional relaxation of the left ventricle precede systolic wall motion abnormalities. The segmental wall motion abnormality is characterized echocardiographically as a reduction in systolic thickening and endocardial excu rsion. The severity and extent of wall motion abnormality depends on multiple factors including severity of stenosis, level of stress, coronary flow reserve, and collateral circulation. Electrocardiographic changes and symptoms may or may not occur until late in the ischemic cascade and may not even be present in patients with mild ischemia. Endothelial dysfunction secondary to hypertensive heart disease and diabetes mellitus can also cause wall motion abnormalities during stress in the absence of flow-limiting epicardial coronary stenosis.7,8

Chapter 61: Stress Echocardiography

1307

echocardiography is that it is more physiologic and higher peak heart rates are achieved. The disadvantage is that images are acquired postexercise as compared to bicycle stress where images are obtained at peak stress. However, bicycle stress achieves lower peak heart rate, and image acquisition is more difficult during peak exercise.

Dobutamine Stress Echocardiography

Fig. 61.1: Ischemic cascade: the sequence of events that occur after a flow-limiting stenosis. The decrease in flow produces biochemical metabolic abnormalities first, followed by detectable perfusion defects by positron emission tomography (PET) or single photon emission computed tomography (SPECT), followed by perfusion, diastolic, and systolic abnormalities that could be detected by stress echocardiography with microbubble and speckle strain, eventually leading to ischemic electrocardiographic changes and anginal symptoms.

TYPES OF STRESS ECHOCARDIOGRAPHY There are various ways to induce stress such as dynamic exercise (treadmill or bicycle), pharmacologic stress (dobutamine, dipyridamole, and adenosine), and pacing stress.9 Hand grip and leg raise are commonly employed as an adjunct to the above-mentioned stress modes to further augment heart rate.10

Exercise Echocardiography Treadmill exercise using the Bruce protocol is the most widely used stress modality in the United States. Supine or semi-supine bicycle stress is widely used in Europe and in some centers in the United States.11 The images in treadmill exercise are acquired immediately postexercise (Figs 61.2A and B). All images are acquired within 30–60 seconds, and the entire sequence is repeated to acquire a second set of images. Reasons for termination of stress test are symptoms of typical angina, marked dyspnea, significant ST segment depression or elevation, sustained arrhythmias, or hemo dynamic compromise (hypotension or systolic blood pressure > 220 mm Hg). The advantage of exercise stress

In patients who are unable to exercise or attain adequate levels of workload, pharmacological stress is preferred. With stress echocardiography, dobutamine is preferred as it is more likely to provoke ischemia as compared to vasodilator agents such as adenosine or dipyridamole. Dobutamine is a sympathomimetic drug that has both b-1 and b-2 adrenergic and a-1 activity. The affinity of dobutamine for b-1 cardiac muscle receptors results in positive inotropic, and, to a lesser extent, positive chronotropic response. These actions are dose-dependent. At lower doses, the inotropic response prevails, and at higher doses, chronotropic activity is predominant. Dobutamine induces myocardial ischemia in patients with flow-limiting coronary artery stenosis by increasing left ventricular contractility, heart rate, wall stress, and therefore, myocardial oxygen demand.12 Dobutamine is administered as an infusion starting at 5 or 10 μg/kg/min and is increased by 5–10 μg/kg every 3 minutes until a maximal dose of 40–50 μg/kg/min or until 85% of the age-predicted maximum heart rate is achieved. Atropine is used in ~30% of patients in conjunction with dobutamine in 0.25 mg increments up to a maximum dose of 2 mg. Low-dose images are obtained at 5 or 10 μg/kg/min or when increased contractility is observed. Peak stress images are obtained after ≥ 85% of maximal predicted heart rate is achieved. The images are displayed as four digitized cine loops that show rest, low dose, peak dose, and recovery.

Vasodilator Stress Echocardiography Major coronary vasodilators used for stress echocardi ography are adenosine and dipyridamole. Adenosine is an endogenously produced substance with potent vasodilator properties. Adenosine induces blood flow heterogeneity by stimulating A2 receptor inducing vasodi latation. Dipyridamole exerts its effects indirectly by reducing the reuptake of adenosine. In the setting of a critical coronary artery stenosis, the flow may increase in the epicardium but falls in the subendocardium distal

1308


A

B

Figs 61.2A and B: The equipment and set-up for performing a treadmill exercise stress echocardiography.

6 minutes after initiation of adenosine. Recovery images for both dipyridamole and adenosine are obtained at 10- and 12-minute intervals from the start of infusion. Adjunctive atropine and handgrip and leg lift exercise may be used to further increase myocardial demand and induce ischemia.14 The advantage of the vasodilator stress test is that if an adverse event occurs, it resolves after termination of infusion or after the administration of aminophylline. The disadvantages are that it is contraindicated in patients with severe chronic obstructive lung disease and those taking theophylline preparations or who have recently ingested caffeine. Vasodilators are also less likely to precipitate ischemia compared to dobutamine. Fig. 61.3: This is an example of a technically difficult dobutamine stress echocardiogram. The noncontrast study had very poor endocardial definition. Administration of contrast improved endocardial delineation. The rest images show akinesis in the apex and apical anterior wall. The low-dose images show increased contractility throughout the myocardium except in the apex and apical anterior wall. At peak stress, no new wall motion abnormalities were observed with persistent akinesis, which is consistent with nonviable tissue. This study is consistent with scar in the apex and apical anterior wall without any significant ischemia. (LV: Left ventricle; RV: Right ventricle). (Movie clip 61.1).

to the flow-limiting stenosis, resulting in ischemia and subsequent wall motion abnormalities.13 Dipyridamole is administered intravenously over 6 minutes at a rate of 0.14 mg/kg/min. Peak stress images are obtained at 4- and 6-minute intervals from the start of infusion. Adenosine is infused starting at 140 μg/kg/min over a 4- to 6-minute period. Peak stress images are obtained at 3 minutes and

Contrast Echocardiography As many as 20–30% of patients referred for stress imaging have suboptimal visualization of the left ventricular endocardial border echocardiographically.15 Echocardiography contrast agents significantly improve the blood–endocardial border visualization at rest and stress.16 Contrast-enhanced echocardiography improves images in patients with poor acoustic windows and thus improves inter- and intraobserver variability and diagn ostic accuracy.15 (Fig. 61.3 and Movie clip 61.1)

Safety of Stress Echocardiography Absolute contraindications for stress echocardiography are: (a) unstable angina, (b) decompensated congestive heart failure, (c) uncontrolled hypertension (> 210/110 mm Hg), (d) uncontrolled cardiac arrhythmias (causing symptoms or hemodynamic compromise), and (e) severe


Fig. 61.4: A baseline echocardiogram showing aortic dissection in a patient hospitalized for chest pain. The stress echocardiogram was cancelled and the patient underwent a computed tomography of the chest, which was consistent with ascending aortic dissection (Type A). The patient underwent subsequent surgery for repair of the aortic dissection. (LA: Left atrium; LV: Left ventricle) (Movie clip 61.2).

symptomatic aortic stenosis. The relative safety of stress echocardiography is similar to other forms of stress testing modalities. In a study of 85,000 patients, the event rate was 1 in 6,574 for exercise, 1 in 557 for dobutamine, and 1 in 1,294 for dipyridamole.17,18 Minor arrhythmias such as premature ventricular contractions, atrial arrhythmia, nonsustained ventricular tachycardia (3%) are common with dobutamine stress and are not necessarily indicative of CAD. Adenosine is well tolerated in the majority (> 80%) of patients. In the Adenoscan Multicenter Trial, the infusion was prematurely terminated in < 0.01% of patients, only 0.8% received aminophylline, and no sustained episodes of atrioventricular block were observed.19

INTERPRETATION OF STRESS ECHOCARDIOGRAPHY Among expert readers, interpretation of stress echocar diography has been highly reproducible.20 Interobserver variability is mostly due to suboptimal image quality and subtle degrees of wall motion abnormality.21 The resting echocardiogram may reveal important diagnosis such as aortic dissection, critical aortic stenosis, and obstructive hypertrophic cardiomyopathy (HCM) (Fig. 61.4 and Movie clip 61.2). A normal response during either exercise or pharma cological stress echocardiogram is an increase in wall thickening and endocardial excursion with decrease in left

1309

Fig. 61.5: Interpretation of response to stress echocardiography for each of the 17 segments. During exercise stress, the thickening and excursion of segments at rest, peak, and recovery are compared. During dobutamine stress, segments are compared at rest, low dose, peak dose, and recovery. Row 1/biphasic: describes an ischemic response in both exercise and dobutamine. Row 2/monophasic: describes a normal response to either exercise or dobutamine stress with inotropic contractile reserve. Row 3/nonphasic: describes scar or nonviable myocardium.

ventricular end-systolic volume. Figure 61.5 describes the various wall motion responses and their interpretation. The left ventricle is divided into a 17-segment model at rest and stress. The 17-segment model with the distribution of the respective coronary arteries is shown in Figure 61.6. Each segment is scored as follows: 1 = normal, 2 = hypokinesis (reduced wall thickening and excursion), 3 = akinesis (no wall thickening and excursion), 4 = dyskinesis (paradoxical motion away from the center of the left ventricle during systole) and 5 = Aneurysmal.22 It is important to remember that the normal myocardial response postexercise is thickening of the myocardium, marked excursion of the endocardium, and almost complete obliteration of the left ventricular cavity.23 With dobutamine stress in patients with rest wall motion abnormality, ischemia is defined as improvement of wall motion at low dose and deterioration of wall motion at peak dose (biphasic response). Therefore, an abnormal (ischemic) response to stress is defined as: (a) a deterioration in left ventricle wall segment thickening and excursion during stress (increase in wall motion of ≥ 1 grade) or (b) a biphasic response with dobutamine stress during which wall motion abnormality improves at baseline (viable myocardium) and then deteriorates at peak stress (ischemia). Furthermore, an abnormal increase in end-systolic left ventricle volume [transient ischemic dilatation (TID)] is associated with multivessel CAD.24,25

1310


Fig. 61.6: The American Society of Echocardiography (ASE) has divided the left ventricle into 17 segments. The schematic demonstrates the relationship between the coronary artery distribution and the corresponding ASE 17 left ventricular segments. Analyses of stress echocardiogram should provide the quantitative result according to this model. The four standard echocardiography views provide evaluation of territories of each of the three main coronary arteries. (Ao: Aorta valve; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Vidhun R Echocardiography pocketcard set, second edition. Börm Bruckmeier Publishing; 2010.

wall segments divided by the number of visualized segments. A normal study has a WMSI of 1.0 at both rest and stress (Fig. 61.7 and Movie clip 61.3) A WMSI of >1.0 at rest and stress is abnormal (Fig. 61.8 and Movie clip 61.4).

Diagnostic Accuracy to Detect CAD

Fig. 61.7: An example of a normal treadmill exercise echocardiogram demonstrating a hyperdynamic response to stress. The standard format to display exercise stress echocardiography images. It demonstrates side-by-side rest-stress images. The heart rate and time of image acquisition postexercise are displayed for each image. The resting study is on the left and postexercise study is on the right. The patient had 1-mm ST depressions, which are likely false-positive ECG changes (Movie clip 61.3). (ECG: Electrocardiogram; LV: Left ventricle; RV: Right ventricle).

A semiquantitative approach for image interpretation is done by calculation of the wall motion score index (WMSI). WMSI is a cumulative sum score of 17 left ventricle

Using angiography as the gold standard for comparison for a > 50% stenosis by quantitative coronary angiography and 70% visually, the overall sensitivity for stress echocardiography is 75–85% and specificity is 80–90% (Table 61.1).26–29 Sensitivity and specificity are comparable in both men and women and among different stress modalities (exercise, dobutamine, and vasodilator).29 Studies comparing the accuracy of single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) and stress echocardiography in the same patient population have shown similar sensitivities for the detection of CAD, with stress echocardiography having a higher specificity (Table 61.2).30 Factors that can cause false-positive or false-negative results are listed in Table 61.3.

Risk Stratification and Prognosis The goal of prognostic testing is based on the premise that patients identified as being at highest risk for adverse


1311

Fig. 61.8: This treadmill exercise echocardiogram demonstrates ischemia. The resting study is normal while the postexercise images reveal anteroapical wall motion abnormalities. The distribution is consistent with obstructive coronary artery disease involving left anterior descending artery. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clip 61.4).

outcomes can be intervened upon to alter the natural history of their disease process, thereby reducing future cardiac risk. Stress echocardiography results can risk stratify and prognosticate patients into a low-risk group (< 1%), intermediate (1–5%), and high (> 5%) risk for major cardiac mortality.31 Table 61.4 summarizes the different variables important in identifying risk and predicting prognosis. Patients with mild-to-moderate wall motion abnormalities (peak WMSI = 1.1–1.7) have an intermediate risk of cardiac events and if stable, may be initially managed medically.32 Patients with peak WMSI > 1.7 and especially those with ejection fraction ≤ 45% are at high risk of cardiac events (Fig. 61.9). Such patients should be appropriately referred to catheterization and consideration of coronary revascularization in order to decrease future cardio vascular risk.33

Extent and Severity of Myocardial Wall Motion Abnormality as Predictors of Prognosis The prognostic value of stress echocardiography is based on its ability to quantify the severity and extent of jeopardized (ischemic) myocardium with exercise or pharmacologic stress. The ischemic extent reflects the areas of myocardium (number of segments) that are abnormal, and maximal severity reflects the degree or magnitude of

wall motion abnormalities in a designated segment, both being quantified at peak stress. Ischemic extent reflects the number of new stress-induced wall motion abnormalities and corresponds roughly to the number of stenosed coronary arteries. Maximal severity reflects the magnitude of ischemia within a designated myocardial segment and reflects the severity of a subtending coronary stenosis within a given coronary artery territory. Estimation of both ischemic extent and maximal severity variables by stress echocardiography provides a functional depiction of a noninvasive coronary angiogram and accurate prognostic assessment of the amount of jeopardized myocardium. The extent and severity of wall motion abnormalities by stress echocardiography are independent and cumu lative predictors of prognosis.34 Thus, prognostic risk stratification by stress echocardiography is both a separate and combined function of the extent and severity of wall motion abnormalities (Fig. 61.10). This proposed model extends the use of stress echocardiography from a simple diagnostic tool, toward establishing its utilization in precise risk stratification, prognosis, and direction of patient management decisions.

Prediction of Myocardial Infarction Versus Cardiac Death by Stress Echocardiography Identifying patients at high risk for ischemic events versus high risk for sudden cardiac death is important in deciding

1312


Table 61.1: Studies with Diagnostic Accuracy of Treadmill, Dobutamine, and Vasodilator Stress Echocardiography Compared to Coronary Angiographya

Studies

Study Size

Peteiro et al. 201258

116 patients

Sensitivity (%)

NPV(%)

Specificity (%)

PPV (%)

Accuracy (%)

Peak supine bicycle SE

84

63

77

Peak treadmill exercise SE

75

80

77

Post treadmill exercise SE

60

78

66

Jang et al. 201159

1,287 Treadmill Exercise SE (Korean population)

68

Aggeli et al. 201160

60 patients dobutamine stress

61

78

83

72

Two-dimensional

80

82

Real time, three-dimensional with perfusion

82

64

11 studies (701 hypertensive patients)

77

89

Mahajan et al. 201027 23 studies (15 SPECT, 14 SE)

94

40

With prior myocardial infarction

83

81

Without prior myocardial infarction

74

85

Patients without RWMA

76

88

Patients with RWMA

82

81

Dipyridamole

85

89

87

Dobutamine

86

86

84

Dipyridamole

72

82

77

Treadmill

79

92

80

Meta-analyses: Gargiulo et al. 201161

Geleijnse et al. 200962

Picano et al. 200829

de Albuquerque Fonseca et al. 200163

62 studies (6,881 patients)

5 studies (435 patients)


Obstructive disease considered > 50% stenosis on coronary angiography. (NPV: Negative predictive value; PPV: Positive predictive value; RWMA: Rest wall motion abnormality; SE: Stress echocardiography; SPECT: Single photon emission positron computed tomography). a

on the optimal clinical management strategy. Patients at high risk for ischemic events but low risk for cardiac death benefit more from medical therapy, but patients at intermediate to high risk of cardiac death benefit more from early revascularization.35 Stress echocardiography is an effective modality at differential risk stratification of patients for the outcome-specific end points of cardiac

death and nonfatal myocardial infarction.33 Patients with ejection fraction < 30% are at high risk of cardiac death (> 4%/year), and these patients should be aggressively managed with optimal medical therapy, consideration of revascularization, device, and cardiac resynchronization therapy (Fig. 61.11). In patients with ejection fraction ≥ 30%, peak WMSI can further risk stratify into a low-


1313

Table 61.2: Comparative Accuracy of Stress Echocardiography Versus Nuclear SPECT Imaging

Echocardiography Studies

Study size

Sensitivity (%)

Specificity (%)

SPECT Sensitivity (%) Specificity (%)

Meta-analyses: Heijenbrok-Kal et al.28

351 patients

79

87

88

73

Imran et al. 2003a 64


70

90

88

67

Fleischmann et al.30

EXSE 24 studies (2,637 patients); EXSPECT 27 studies (3,237 patients)

85

77

87

64

O’Keefe et al.65

SE 12 studies (913 patients); SPECT 12 studies (2,626 patients)

81

89

90

72

Pharmacologic SE 14 studies (1,049 patients); Pharmacologic SPECT 14 studies

81

83

87a

75a

89b

83b

Dipyridamole stress echocardiography versus SPECT. Adenosine SPECT. (EXSE: Exercise stress echocardiography; EXSPECT: Exercise SPECT; SE: Stress echocardiography; SPECT: Single photon emission computed tomography). a

b

Table 61.3: Factors that Affect Accuracy of Stress Echocardiography for Detecting Hemodynamic Obstructive Coronary Artery Disease Compared with Coronary Angiography

False Positive

False Negative

Hypertensive response to stress

Submaximal stress (< 85% maximal predicted heart rate)

Microvascular disease: e.g. diabetes, left ventricular hypertrophy, syndrome X, hypertrophic cardiomyopathy

Poor image quality

Cardiomyopathies

Delayed poststress image acquisition

Paradoxical septal motion, e.g. postcardiac surgery, left bundle branch block

Very mild ischemia, circumflex coronary stenosis, branch or distal stenosis

Coronary spasm, endothelial dysfunction

Good coronary reserve (collateral circulation), potent endothelial function

Localized basal inferior wall motion abnormalities

Antianginal drug therapy during testing (calcium channel blockers, b-blockers, nitrates)

Fig. 61.9: Cardiac event rate per year as a function of wall motion score index. Worse cardiac event rate is observed with higher peak wall motion score index. Source: Reprinted with permission of Elsevier from Yao S, Qureshi E, Sherrid MV, Chaudhry FA. Practical applications in stress echocardiography: risk stratification and prognosis in patients with known or suspected ischemic heart disease. Journal of the American College of Cardiology. 2003;42(6):1084-90.

Fig. 61.10: Cumulative effect of ischemic extent and maximal severity (jeopardized myocardium) of wall motion abnormalities on event rate per year. The event rate increases as a curvilinear function of both extent and severity combined. Source: Reprinted with permission of Elsevier from Yao S, Qureshi E, Syed A, Chaudhry FA. Novel stress echocardiographic model incorporating the extent and severity of wall motion abnormality for risk stratification and prognosis. American Journal of Cardiology. 2004;94(6):715-9.

1314


Table 61.4: Stress Echocardiography Predictors of Risk

Very Low Risk < 0.5 to 1%/year Low Risk < 2%/year Intermediate Risk 2% to 4%/year

High Risk (> 4%/year)

Incremental Risk/Other Independent Predictors

Normal exercise stress echocardiography

Normal pharmaco- pWMSI 1.0–1.7 logical stress test Resting ejection fraction > 50%

Extensive resting wall motion abnormalities (4–7 segments)

Age Male gender Prior history of CHF or MI

> 6 METs achieved

Submaximal stress test (< 85% MPHR)

Single vessel disease (LCx or RCA)

Resting ejection fraction < 45%

> 3 CAD risk factors Left atrial size

Off anti-ischemic therapy

Extensive ischemia (4–5 segments)

Multivessel coronary artery disease Transient ischemic left ventricular cavity dilatation

pWMSI > 1.7 Ischemia induced at lower workload

Abnormal Right ventricular wall motion Limited exercise capacity. Inability to exercise

On anti-ischemic therapy

Ischemic ECG or symptoms on stress High pretest likelihood

Achieved > 85% MPHR

(CAD: Coronary artery disease; CHF: Congestive heart failure; ECG: Electrocardiogram; LCx: Left circumflex; METs: Metabolic equivalent of tasks; MI: Myocardial infarction; MPHR: Maximal predicted heart rate; pWMSI: Peak wall motion score index; RCA: Right coronary artery). Source: Modified with permission of Elsevier from Pellikka PA, Nagueh SF, Elhendy AA, et al. Echocardiography recommendations for performance, interpretation and application of stress echocardiography. Journal of American Society of Echocardiography. 2007;20(9):1021-41.

Fig. 61.11: Schematic for the risk stratification of patients undergoing stress echocardiography. (CAD: Coronary artery disease; CD: Cardiac death; CRT: Cardiac re-synchronization therapy; EF: Ejection fraction; WMSI: Wall motion score index). Source: Reprinted with permission of Elsevier from Bangalore S, Yao S, Chaudhry FA. Prediction of myocardial infarction versus cardiac death by stress echocardiography. Journal of the American Society of Echocardiography. 2009;22(3):261-7).


1315

Fig. 61.12: This figure demonstrates an abnormal left ventricular volume response to stress. The resting study is normal. Postexercise, there is evidence of anteroseptal, apical, and lateral ischemia, resulting in left ventricular dilatation or transient ischemic dilatation (TID). Cardiac catheterization was consistent with severe multivessel coronary artery disease. (LV: Left ventricle). (Movie clip 61.5).

Fig. 61.13: Cardiac event rate per year as a function of stress echocardiogram results and transient ischemic dilatation (TID). A 15-fold increase in cardiac event rate is observed with TID. Source: Reprinted with permission of Elsevier from Yao S, Shah A, Bangalore S, Chaudhry FA. Transient ischemic left ventricular cavity dilation is a significant predictor of severe and extensive coronary artery disease and adverse outcome in patients undergoing stress echocardiography. Journal of the American Society of Echocardiography. 2007;20(4):352-8).

risk group (pWMSI = 1.0; cardiac death rate < 1.0%/year) managed with risk factor modification alone, a low-inter mediate risk group (pWMSI = 1.1–1.7; cardiac death rate 1.0–2.5%/year) managed with optimal medical therapy and consideration of revascularization for symptom relief only, and a high-intermediate risk group (WMSI >1.7; cardiac death rate 2.5–4%/year) managed with optimal medical therapy and consideration of revascularization (to decrease future cardiac risk).36 Table 61.5 summarizes the list of studies reporting the prognostic value of stress echocardiography.

WMSI, and a worse prognosis than patients without TID (Fig. 61.13). TID during stress echocardiography is a sensitive marker of severe and extensive angiographic CAD and is associated with a very high risk of cardiac events (19.7%/year event rate).25 These patients should be referred for consideration of catheterization and coronary revascularization as the best means to modify and reduce future cardiac risk.24,25

Transient Ischemic Left Ventricular Cavity Dilatation Transient ischemic left ventricular cavity dilatation (TID) signifies an increase in left ventricular cavity size after a wall motion abnormality induced with exercise or dobu tamine stress. Plausible clinical explanations for TID include: subendocardial ischemia, systolic left ventricular dysfunction, and actual physical left ventricular dilatation in end-diastole (Fig. 61.12 and Movie clip 61.5). TID has a high sensitivity (100%) and moderate specificity (54%) for the detection of severe and extensive angiographic CAD.25 Patients with TID have a greater extent and severity of stress-induced wall motion abnormality, higher peak

Role of Right Ventricular Wall Motion Abnormalities in Risk Stratification and Prognosis The right ventricle is often termed the “forgotten cham ber.” Evidence from clinical studies emphasizes the importance of evaluating right ventricular function during routine echocardiography. Right ventricular function has prognostic implications in patients with CAD and heart failure.37 With stress echocardiography, abnormal right vent ricle function (ischemia or infarction) can further risk stratify and add prognostic value to left ventricular functional parameters.38 Patients with both an abnormal right ventricle and left ventricle have a worse prognosis. Right ventricular wall motion analysis should be routinely assessed in patients referred for stress echocardiography for more effective and complete risk stratification.

1316


Table 61.5: Studies Reporting the Prognostic Value of Stress Echocardiography

Studies

No. of Patients

Follow-Up Duration Normal

Abnormal

Wever Pinzon et al.66

311 HIV patients

2.9 ± 1.9 years

0.6%/year MI/CD

11.8%/year MI/CD

Bangalore et al.

1,002 LVH patients

2.6 ± 1.1 years

1.1%/year MI/CD

4.9%/year MI/CD

Wake et al.68

890 patients (contrast-enhanced DSE)

30 ± 17 months

88% 2-year (men)

74% 2-year (men)

91% 2-year (women)

80% 2-year (women)

67

Metz et al.69

Meta-analyses 3,021 patients

33 months

0.54%/year-MI/CD

—

Chaowalit et al.70

3,014 patients (DSE)

Median 6.3 years

93% 5-year MI/ revascularization

—

78% 5-year all-cause mortality D’Andrea et al.

607 patients (supine bicycle SE) Mean 46 months

96% 5-year

84% 5-year

Biagini et al.

3,381 patients (DSE)

2.5%/year (men) MI/CD

5.9%/year (men)

1.2%/year (women) MI/CD

4.6%/year (women)

71

72

Sozzi et al.73

401 patients (DSE)

7 ± 3.4 years

5 ± 1.7 years

0.8%/year (first 3 years) MI/CD 1.7%/year (between 4th and 6th year of follow-up)

Yao et al.31

1,500 patients

2.7 ± 1.0 years

0.9%/year

4.2%/year overall; 1.4%/year TME, 4.7% DSE

Hoque et al.74

206 patients EXSE

8.8 ± 2.9 years

0.8%/year all-cause mortality < 0.5%/year CD

Moderate to large ischemia: 5.5%/ year CD

Sicari et al.75

7,333 patients Dipy or DSE

2.6 ± 3 years

0.9%/year or 92% at ~16 years

71.2% at ~16 years CD

Elhendy et al.76

4,347 patients EXSE

Median 3 years

97.5% at 5 years (< 1%/year)

89.7% at 5 years CD

Marwick et al.77,78

1,581 patients DSE 5,375 patients EXSE

3.8 years ± 1.9 years 5.5 ± 1.9 years

1.2%/year 1.0%/year

— 2–4%/year CD

Krivokapich et al.79

558 patients DSE

12 months

10% all cardiac events 3% hard events

34% all cardiac events 10% hard events

Poldermans et al.80

1,734 patients DSE

Median 3 years (range 6–96 months)

1.3%/year

—

McCully et al.81

1,325 patients EXSE

Median 2 years (range 5–65 months)

0.9%/year

—

(ACM: All-cause mortality; CD: Cardiac death; Dipy: Dipyridamole; DSE: Dobutamine stress echocardiography; EXSE: Exercise stress echocardiography; HIV: Human immunodeficiency virus; LVH: Left ventricular hypertrophy; MI: Myocardial infarction; TME: Treadmill exercise stress echocardiography).


Role of Left Atrial Size in Risk Stratification and Prognosis An increase in left atrial dimension is a risk factor for atrial fibrillation, stroke, and death and is closely related to general cardiovascular mortality.39 Left atrial size reflects the chronicity and magnitude of increased left ventricular filling pressure. Left atrial size is a marker of the severity and duration of left ventricular diastolic dysfunction in patients without significant mitral valve disease or systolic heart failure. Left atrial size has been found to further risk stratify patients with both normal and abnormal stress echocar diography results.40 A normal stress echocar diography in the setting of a normal left atrial size confers a benign prognosis (< 1% year). Left atrial size alone provides independent and incremental prognostic value, indep endent of traditional risk factors, ejection fraction, and stress echocardiographic variables. Left atrial size should be routinely incorporated in prognostic interpretation of stress echocardiography.

“Warranty Time” of a Normal Stress Echocardiogram A normal stress echocardiogram confers a benign prog nosis (< 1%/year) in most subgroups of patients. However, it is unclear at what time a stress echocardiogram should be repeated for risk stratification and prognosis if clinically warranted (change in chest pain or clinical symptom characteristics). In patients with a normal stress echocardiogram, the event rate at the end of 6, 12, and 18 months was <1%/year.41 After 18 months, the event rate in patients with a normal stress echocardiogram increases to >1%/year. Thus, a normal stress echocardiogram has a benign prognosis (< 1%/year) for up to 18 months and may be repeated after that if clinically warranted for effective risk stratification.

Impact of Stress Echocardiography on Patient Outcome The ultimate maturity of an imaging modality is confi rmed by patient outcome data. There has been a demo nstrated parallel between the degree of abnormal stress echocardiography results and referral to coronary angio graphy and revascularization.42 Despite physician

1317

self-referral incentives for coronary angiography, stress echocardiography is an effective gatekeeper for an invasive management strategy. Patients with normal stress echocardiography studies (pWMSI = 1.0) have uniformly low referral rates for early coronary angiography (1.7% at 30 days) and late revascularization (2.8% percutaneous coronary intervention, 1.1% coronary artery bypass graft surgery at 2 years). The frequency of referral to coronary angiography and revascularization increased in proportion to magnitude of the extent and severity of abnormal stress echocardiography. The fact that only a minority of patients with abnormal stress echocardiography were referred for coronary angiography and revascularization implies that such decisions are often complex and incorporate other comorbidities into the decision on whether to refer for invasive testing. These findings are also consistent with a low referral for coronary angiography and revascularization following abnormal nuclear scintigraphy studies.43

Cost-Effectiveness of Stress Echocardiography in Postmyocardial Infarction Patients Cost-effectiveness of the four testing strategies in patients with prior myocardial infarction was previously evaluated.44 A primary cardiac catheterization strategy (Strategy 1) was found to be 23% more expensive, a primary stress electrocardiogram (ECG)/exercise treadmill test strategy (Strategy 2 and Strategy 3) was 82% more expensive when compared to a primary stress echocardiography strategy (Strategy 4). In patients undergoing stress echocardiography followed by cardiac catheterization (Strategy 4), the total cost savings was $57,293/patient compared to a primary cardiac catheterization strategy, which translated into cost savings of $217/patient correctly identified. Given the high-risk nature of postmyocardial infarction patients, it is no surprise that a primary stress ECG/exercise treadmill test strategy was not cost-effective. The cost-effectiveness analysis of the postmyocardial infarction patient study showed that a strategy based on initial stress testing and cardiac catheterization only in patients with abnormal stress echocardiogram is ~$217/ patient correctly identified, more economical than a primary invasive strategy. With a projected incidence of 1.1 million new, recurrent, or silent myocardial infarctions for 2013 by American Heart Association (AHA),45 the above data could translate into cost savings of billions of dollars each year. This is in concordance with previous studies by

1318


Shaw and colleagues who showed that patients with stable angina who went directly to coronary angiography had a much higher utilization of subsequent revascularization but with a similar rate of death and myocardial infarction, and much higher attendant costs compared to those who were tested first with perfusion imaging and referred to catheterization dependent on the findings.46 In patients with high-risk features (ST changes, unstable angina, elevated cardiac enzymes), a primary invasive strategy may be more appropriate.

Doppler Hemodynamic with Stress Echocardiography

ACC/AHA recommends stress echocardiography as a Class I indication for symptom assessment and severity of mitral stenosis. An increase in mean transmitral pressure gradient > 15 mm Hg or an increase in peak pulmonary pressure > 60 mm Hg is considered significant to warrant invasive strategy. In asymptomatic patients with severe mitral regurgitation, left ventricular dysfunction can be evaluated with exercise stress echocardiography.50 In asymptomatic patients with severe mitral regurgitation, pulmonary artery systolic pressure > 60 mm Hg during exercise may lower threshold for valve surgery.50

Hypertrophic Cardiomyopathy

The most important indication for surgical intervention in patients with hemodynamically significant aortic or mitral valve disease is the development of symptoms, as emphasized in the recent guidelines.47 As valvular heart disease progresses, the patient may be unaware of these chronic changes in effort tolerance but instead adapt to the symptoms by reducing physical activity and lifestyle modifications. Therefore, exercise stress echocardiography provides objective evidence in assessing symptoms, exercise capacity, and hemodynamic changes of the valve during stress that may be absent at rest.

Asymmetric hypertrophic cardiomyopathy (HCM) is a common cause of dyspnea and is associated with sudden cardiac death. HCM may be present with or without left ventricular outflow tract (LVOT) gradient. ACC/AHA guidelines for the diagnosis and treatment of HCM assign exercise echocardiography as Class IIa for the detection and quantification of exercise-induced dynamic LVOT obstruction in patients who do not have significant gradients at rest or provocation.51

Aortic Valve Disease

Many patients with diastolic dysfunction have symptoms of dyspnea on exertion. The symptoms are due to rise in left ventricular filling pressures that is needed to maintain adequate left ventricular filling and stroke volume during exercise. Stress echocardiography can assess latent dias tolic dysfunction not apparent at rest but only at stress. When relaxation is normal, the mitral annulus velocity (e') and mitral inflow velocity (E) increase proportionally (~25%), whereas E/e' ratio remains unchanged or is reduced (< 8). In patients with impaired myocardial relaxation, the increase in e' with exercise is much less than that of mitral E velocity, such that the E/e' ratio increases (> 15).52 Therefore, E/e' ratio increases with exercise compared with rest in patients with latent diastolic dysfunction.

Exercise stress echocardiography is contraindicated in severe symptomatic aortic stenosis. In patients with asymp tomatic aortic stenosis, stress echocardiography can provide prognostic information by unmasking symptoms.48 An important role of stress echocardiography is in patients with left ventricular dysfunction and “low-flow” or low-gradient aortic stenosis. Low-dose dobutamine is used to increase inotropic contractility and increasing stroke volume differentiating pseudosevere aortic stenosis due to left ventricular dysfunction from true aortic stenosis. The American College of Cardiology (ACC)/American Heart Association (ACH) recommends stress echocardiography as Class IIa for low-flow, low-gradient aortic stenosis and Class IIb for symptom assessment.49

Mitral Valve Disease In some patients with severe asymptomatic mitral stenosis and symptomatic moderate stenosis, exercise stress echocardiography may precipitate or reproduce symptom.

Latent Diastolic Dysfunction

Dynamic Pulmonary Hypertension In normal subjects, exercise increases stroke volume while pulmonary vascular resistance decreases. Normal values are defined by systolic pulmonary artery pressure < 43 mm Hg during exercise.53 Exercise-induced pulmonary


Fig. 61.14: An example of a nonischemic treadmill exercise echo cardiogram demonstrating dynamic pulmonary hypertension. The resting study is on the left that shows normal right ventricular size and function. The postexercise images on the right show right ventricular dilatation and compression of the left ventricular cavity with paradoxical septal motion. The abnormal septal motion is due to right ventricular pressure overload and not due to ischemia. This is a typical example of dynamic pulmonary hypertension during exercise. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). (Movie clip 61.6).

hypertension has been recognized as an early phase of the pulmonary hypertension spectrum, especially in highrisk patients.54 The abnormal exercise-induced increase in pulmonary pressures can be ascribed to elevated cardiac output (e.g. in athletes) or to a normal increase in flow but a rise in resistance due to limited capability of the pulmonary vascular bed (e.g. chronic obstructive pulmonary disease or advanced age) (Fig. 61.14 and Movie clip 61.6).

STRESS ECHOCARDIOGRAPHY: FUTURE DIRECTIONS 2D Strain, Myocardial Perfusion and Three Dimensional (3D) Stress Echocardiography The interaction of ultrasound energy with the myocardium results in unique random acoustic speckle patterns.55 Information regarding the motion and displacement of acoustic speckle of the myocardium can be tracked automatically throughout the cardiac cycle using sophis ticated algorithms. The patterns can be used to obtain strain and strain rate and thus quantification of wall motion abnormality.55

1319

Microbubble image-enhancing agents such as perflutren lipid microspheres (Optison/Definity) microbubbles have been used to assess myocardial perfusion. The perfusion information in conjunction with the corresponding regional wall motion improves sensitivity to detect flow-limiting CAD.56 Major technological advances have led to the development of real time, 3D stress echocardiography. It allows for numerous tomographic interrogations, eliminates off-axis acquisition and analysis, avoids foreshortening of the apex, thus allowing multiple crosssectional views of the left ventricle, and more precise comparison of similar segments to improve the detection of localized ischemia.57 3D stress echocardiography overcomes the difficulties in acquiring multiple views immediately postexercise. Furthermore, multiple tomography views can be evaluated for better assessment of wall motion abnormality.

REFERENCES 1. Wann LS, Faris JV, Childress RH, et al. Exercise crosssectional echocardiography in ischemic heart disease. Circulation. 1979;60(6):1300–8. 2. Armstrong WF, Zoghbi WA. Stress echocardiography: current methodology and clinical applications. J Am Coll Cardiol. 2005;45(11):1739–47. 3. Pellikka PA, Nagueh SF, Elhendy AA, et al. American Society of Echocardiography. American Society of Echocardiography recommendations for performance, interpretation, and application of stress echocardiography. J Am Soc Echocardiogr. 2007;20(9):1021–41. 4. Douglas PS, Garcia MJ, Haines DE, et al. ACCF/ASE/ AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Society of Echocardiography, American Heart Association, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomography, and Society for Cardiovascular Magnetic Resonance Endorsed by the American College of Chest Physicians. J Am Coll Cardiol. 57(9):1126–66. 5. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012). Eur Heart J. 33(19):2451–96. 6. Nesto RW, Kowalchuk GJ. The ischemic cascade: temporal sequence of hemodynamic, electrocardiographic and symptomatic expressions of ischemia. Am J Cardiol. 1987; 59(7):23C–30C.

1320


7. Lerman A, Holmes DR Jr, Bell MR, et al. Endothelin in coronary endothelial dysfunction and early atherosclerosis in humans. Circulation. 1995;92(9):2426–31. 8. Asghar O, Al-Sunni A, Khavandi K, et al. Diabetic cardio myopathy. Clin Sci. 2009;116(10):741–60. 9. Plonska-Gosciniak E, Kleinrok A, Gackowski A, et al. Diagnostic and prognostic value of rapid pacing stress echocardiography for the detection of coronary artery disease: influence of pacing mode and concomitant antiischemic therapy (final results of multicenter study Pol-RAPSE). Echocardiography. 2008;25(8):827–34. 10. Yao SS, Moldenhauer S, Sherrid MV. Isometric handgrip exercise during dobutamine-atropine stress echocar diography increases heart rate acceleration and decreases study duration and dobutamine and atropine dosage. Clin Cardiol. 2003;26(5):238–42. 11. Badruddin SM, Ahmad A, Mickelson J, et al. Supine bicycle versus post-treadmill exercise echocardiography in the detection of myocardial ischemia: a randomized single-blind crossover trial. J Am Coll Cardiol. 1999;33(6): 1485–90. 12. Barasch E, Wilansky S. Dobutamine stress echocardiography in clinical practice with a review of the recent literature. Tex Heart Inst J. 1994;21(3):202–10. 13. Picano E, Masini M, Lattanzi F, et al. Role of dipyridamoleechocardiography test in electrocar diographically silent effort myocardial ischemia. Am J Cardiol. 1986;58(3):235–7. 14. Brown BG, Josephson MA, Petersen RB, et al. Intravenous dipyridamole combined with isometric handgrip for near maximal acute increase in coronary flow in patients with coronary artery disease. Am J Cardiol. 1981;48(6):1077–85. 15. Senior R, Becher H, Monaghan M, et al. Contrast echocar diography: evidence-based recommendations by European Association of Echocardiography. Eur J Echocardiogr. 2009;10(2):194–212. 16. Crouse LJ, Cheirif J, Hanly DE, et al. Opacification and border delineation improvement in patients with suboptimal endocardial border definition in routine echocardiography: results of the Phase III Albunex Multicenter Trial. J Am Coll Cardiol. 1993;22(5):1494–500. 17. Varga A, Garcia MA, Picano E; International Stress Echo Complication Registry. Safety of stress echocardiography (from the International Stress Echo Complication Registry). Am J Cardiol. 2006;98(4):541–3. 18. Bremer ML, Monahan KH, Stussy VL, et al. Safety of dobutamine stress echocardiography supervised by registered nurse sonographers. J Am Soc Echocardiogr. 1998;11(6):601–05. 19. Cerqueira MD, Verani MS, Schwaiger M, et al. Safety profile of adenosine stress perfusion imaging: results from the Adenoscan Multicenter Trial Registry. J Am Coll Cardiol. 1994;23(2):384–9. 20. Picano E, Lattanzi F, Orlandini A, et al. Stress echocardio graphy and the human factor: the importance of being expert. J Am Coll Cardiol. 1991;17(3):666–9.

21. Hoffmann R, Lethen H, Marwick T, et al. Analysis of interinstitutional observer agreement in interpretation of dobutamine stress echocardiograms. J Am Coll Cardiol. 1996;27(2):330–6. 22. Chaudhry FA, Tauke JT, Alessandrini RS, et al. Prognostic implications of myocardial contractile reserve in patients with coronary artery disease and left ventricular dysfunction. J Am Coll Cardiol. 1999;34(3):730–8. 23. Pislaru C, Belohlavek M, Bae RY, et al. Regional asynchrony during acute myocardial ischemia quantified by ultrasound strain rate imaging. J Am Coll Cardiol. 2001;37(4):1141–8. 24. Bangalore S, Yao SS, Chaudhry FA. Role of angiographic coronary artery collaterals in transient ischemic left ventricular cavity dilatation during stress echocardiography. Clin Cardiol. 2006;29(7):305–10. 25. Yao SS, Shah A, Bangalore S, et al. Transient ischemic left ventricular cavity dilation is a significant predictor of severe and extensive coronary artery disease and adverse outcome in patients undergoing stress echocardiography. J Am Soc Echocardiogr. 2007;20(4):352–8. 26. Elhendy A, Geleijnse ML, Roelandt JR, et al. Comparison of dobutamine stress echocardiography and 99m-technetium sestamibi SPECT myocardial perfusion scintigraphy for predicting extent of coronary artery disease in patients with healed myocardial infarction. Am J Cardiol. 1997;79(1): 7–12. 27. Mahajan N, Polavaram L, Vankayala H, et al. Diagnostic accuracy of myocardial perfusion imaging and stress echo cardiography for the diagnosis of left main and triple vessel coronary artery disease: a comparative meta-analysis. Heart. 2010;96(12):956–66. 28. Heijenbrok-Kal MH, Fleischmann KE, Hunink MG. Stress echocardiography, stress single-photon-emission computed tomography and electron beam computed tomography for the assessment of coronary artery disease: a meta-analysis of diagnostic performance. Am Heart J. 2007;154(3):415–23. 29. Picano E, Molinaro S, Pasanisi E. The diagnostic accuracy of pharmacological stress echocardiography for the asse ssment of coronary artery disease: a meta-analysis. Cardiovasc Ultrasound. 2008;6:30. 30. Fleischmann KE, Hunink MG, Kuntz KM, et al. Exercise echocardiography or exercise SPECT imaging? A meta-analysis of diagnostic test performance. JAMA. 1998;280(10):913–20. 31. Yao SS, Qureshi E, Sherrid MV, et al. Practical applications in stress echocardiography: risk stratification and prognosis in patients with known or suspected ischemic heart disease. J Am Coll Cardiol. 2003;42(6): 1084–90. 32. Boden WE, O’Rourke RA, Teo KK, et al; COURAGE Trial Research Group. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med. 2007;356(15):1503–16. 33. Bangalore S, Yao SS, Chaudhry FA. Prediction of myocardial infarction versus cardiac death by stress echocardiography. J Am Soc Echocardiogr. 2009;22(3):261–7.


34. Yao SS, Qureshi E, Syed A, et al. Novel stress echocardiographic model incorporating the extent and severity of wall motion abnormality for risk stratification and prognosis. Am J Cardiol. 2004;94(6):715–9. 35. Pitt B, Waters D, Brown WV, et al. Aggressive lipid-lowering therapy compared with angioplasty in stable coronary artery disease. Atorvastatin versus Revascularization Treat ment Investigators. N Engl J Med. 1999;341(2):70–6. 36. Bangalore S, Yao SS, Chaudhry FA. Stress function index, a novel index for risk stratification and prognosis using stress echocardiography. J Am Soc Echocardiogr. 2005;18(12):1335–42. 37. Ghio S, Gavazzi A, Campana C, et al. Independent and additive prognostic value of right ventricular systolic function and pulmonary artery pressure in patients with chronic heart failure. J Am Coll Cardiol. 2001;37(1):183–8. 38. Bangalore S, Yao SS, Chaudhry FA. Role of right ventricular wall motion abnormalities in risk stratification and prognosis of patients referred for stress echocardiography. J Am Coll Cardiol. 2007;50(20):1981–9. 39. Benjamin EJ, D’Agostino RB, Belanger AJ, et al. Left atrial size and the risk of stroke and death. The Framingham Heart Study. Circulation. 1995;92(4):835–41. 40. Bangalore S, Yao SS, Chaudhry FA. Role of left atrial size in risk stratification and prognosis of patients undergoing stress echocardiography. J Am Coll Cardiol. 2007;50(13):1254–62. 41. Bangalore S, Gopinath D, Yao SS, et al. Risk stratification using stress echocardiography: incremental prognostic value over historic, clinical, and stress electrocardiographic variables across a wide spectrum of Bayesian pretest probabilities for coronary artery disease. J Am Soc Echocardiogr. 2007;20(3):244–52. 42. Yao SS, Bangalore S, Chaudhry FA. Prognostic implications of stress echocardiography and impact on patient outcomes: an effective gatekeeper for coronary angiography and reva scularization. J Am Soc Echocardiogr. 2010;23(8):832–9. 43. Bateman TM, O’Keefe JH Jr, Dong VM, et al. Coronary angiographic rates after stress single-photon emission computed tomographic scintigraphy. J Nucl Cardiol. 1995; 2(3):217–23. 44. Bangalore S, Yao SS, Puthumana J, et al. Increm ental prognostic value of stress echocardiography over clinical and stress electrocardiographic variables in patients with prior myocardial infarction: “warranty time” of a normal stress echocardiogram. Echocardiography. 2006;23(6): 455–64. 45. Go AS, Mozaffarian D, Roger VL, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics–2013 update: a report from the American Heart Association. Circulation. 2013;127(1):e6–e245. 46. Shaw LJ, Marwick TH, Berman DS, et al. Incremental cost-effectiveness of exercise echocardiography vs. SPECT imaging for the evaluation of stable chest pain. Eur Heart J. 2006;27(20):2448–58. 47. Picano E, Pibarot P, Lancellotti P, et al. The emerging role of exercise testing and stress echocardiography in valvular heart disease. J Am Coll Cardiol. 2009;54(24):2251–60.

1321

48. Lancellotti P, Lebois F, Simon M, et al. Prognostic importance of quantitative exercise Doppler echocardiography in asymptomatic valvular aortic stenosis. Circulation. 2005; 112(9 Suppl):I377–82. 49. Bonow RO, Carabello BA, Chatterjee K, et al; American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthe siologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2008;52(13):e1–142. 50. Kang DH, Kim JH, Rim JH, et al. Comparison of early surgery versus conventional treatment in asymptomatic severe mitral regurgitation. Circulation. 2009;119(6): 797–804. 51. Gersh BJ, Maron BJ, Bonow RO, et al. 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Thorac Cardiovasc Surg. 142(6):e153–203. 52. Ha JW, Oh JK, Pellikka PA, et al. Diastolic stress echocar diography: a novel noninvasive diagnostic test for diastolic dysfunction using supine bicycle exercise Doppler echocardiography. J Am Soc Echocardiogr. 2005;18(1): 63–8. 53. Grünig E, Weissmann S, Ehlken N, et al. Stress Doppler echocardiography in relatives of patients with idiopathic and familial pulmonary arterial hypertension: results of a multicenter European analysis of pulmonary artery pressure response to exercise and hypoxia. Circulation. 2009;119(13):1747–57. 54. Alkotob ML, Soltani P, Sheatt MA, et al. Reduced exercise capacity and stress-induced pulmonary hypertension in patients with scleroderma. Chest. 2006;130(1):176–81. 55. Abraham TP, Pinheiro AC. Speckle-derived strain a better tool for quantification of stress echocardiography? J Am Coll Cardiol. 2008;51(2):158–60. 56. Pellikka PA, Mulvagh SL. Echocardiography contrast for image optimization: beyond confidence, it is a matter of accuracy. JACC Cardiovasc Imaging. 2008;1(2):153–5. 57. Aggeli C, Giannopoulos G, Misovoulos P, et al. Real time three-dimensional dobutamine stress echocardiography for coronary artery disease diagnosis: validation with coronary angiography. Heart. 2007;93(6):672–5. 58. Peteiro J, Bouzas-Mosquera A, Estevez R, et al. Headto-head comparison of peak supine bicycle exercise echocardiography and treadmill exercise echocardiography at peak and at post-exercise for the detection of coronary artery disease. J Am Soc Echocardiogr. 2012;25(3):319–26.

1322


59. Jang JY, Sohn IS, Kim JN, et al. Treadmill exercise stress echocardiography in patients with no history of coronary artery disease: a single-center experience in korean population. Korean Circ J. 2011;41(9):528–34. 60. Aggeli C, Felekos I, Roussakis G, et al. Value of real time three-dimensional adenosine stress contrast echocar diography in patients with known or suspected coronary artery disease. Eur J Echocardiogr. 2011;12(9):648–55. 61. Gargiulo P, Petretta M, Bruzzese D, et al. Myocardial perfusion scintigraphy and echocardiography for detecting coronary artery disease in hypertensive patients: a metaanalysis. Eur J Nucl Med Mol Imaging. 2011;38(11):2040–9. 62. Geleijnse ML, Krenning BJ, van Dalen BM, et al. Factors affecting sensitivity and specificity of diagnostic testing: dobutamine stress echocardiography. J Am Soc Echocardiogr. 2009;22(11):1199–208. 63. de Albuquerque Fonseca L, Picano E. Comparison of dipyridamole and exercise stress echocardiography for detection of coronary artery disease (a meta-analysis). Am J Cardiol. 2001;87(10):1193–6; A4. 64. Imran MB, Pálinkás A, Picano E. Head-to-head comparison of dipyridamole echocardiography and stress perfusion scintigraphy for the detection of coronary artery disease: a meta-analysis. Comparison between stress echo and scintigraphy. Int J Cardiovasc Imaging. 2003;19(1):23–8. 65. O’Keefe JH Jr, Barnhart CS, Bateman TM. Comparison of stress echocardiography and stress myocardial perfusion scintigraphy for diagnosing coronary artery disease and assessing its severity. Am J Cardiol. 1995;75(11):25D–34D. 66. Wever Pinzon O, Silva Enciso J, Romero J, et al. Risk stratification and prognosis of human immunodeficiency virus-infected patients with known or suspected coronary artery disease referred for stress echocardiography. Circ Cardiovasc Imaging. 2011;4(4):363–70. 67. Bangalore S, Yao SS, Chaudhry FA. Usefulness of stress echocardiography for risk stratification and prognosis of patients with left ventricular hypertrophy. Am J Cardiol. 2007;100(3):536–43. 68. Wake R, Takeuchi M, Yoshikawa J, Yoshiyama M. Effects of gender on prognosis of patients with known or susp ected coronary artery disease undergoing contrastenhanced dobutamine stress echocardiography. Circ J. 2007;71(7):1060–66. 69. Metz LD, Beattie M, Hom R, et al. The prognostic value of normal exercise myocardial perfusion imaging and exercise echocardiography: a meta-analysis. J Am Coll Cardiol. 2007;49(2):227–37. 70. Chaowalit N, McCully RB, Callahan MJ, et al. Outcomes after normal dobut amine stress echo cardiography and

predictors of adverse events: long-term follow-up of 3014 patients. Eur Heart J. 2006;27(24):3039–44. 71. D’Andrea A, Severino S, Caso P, et al. Risk stratification and prognosis of patients with known or suspected coronary artery disease by use of supine bicycle exercise stress echocardiography. Ital Heart J. 2005;6(7):565–72. 72. Biagini E, Elhendy A, Bax JJ, et al. Seven-year follow-up after dobutamine stress echocardiography: impact of gen der on prognosis. J Am Coll Cardiol. 2005;45(1):93–7. 73. Sozzi FB, Elhendy A, Roelandt JR, et al. Long-term prognosis after normal dobutamine stress echocardiography. Am J Cardiol. 2003;92(11):1267–70. 74. Hoque A, Maaieh M, Longaker RA, et al. Exercise echocardiography and thallium-201 single-photon emi ssion computed tomography stress test for 5- and 10-year prognosis of mortality and specific cardiac events. J Am Soc Echocardiogr. 2002;15(11):1326–34. 75. Sicari R, Pasanisi E, Venneri L, et al. Echo Persantine International Cooperative (EPIC) Study Group; Echo Dobutamine International Cooperative (EDIC) Study Group. Stress echo results predict mortality: a large-scale multicenter prospective international study. J Am Coll Cardiol. 2003;41(4):589–95. 76. Elhendy A, Mahoney DW, Khandheria BK, et al. Prognostic significance of the location of wall motion abnormalities during exercise echocardiography. J Am Coll Cardiol. 2002;40(9):1623–9. 77. Marwick TH, Case C, Vasey C, et al. Prediction of mortality by exercise echocardiography: a strategy for combination with the duke treadmill score. Circulation. 2001;103(21):2566–71. 78. Marwick TH, Case C, Sawada S, et al. Prediction of mortality using dobutamine echocardiography. J Am Coll Cardiol. 2001;37(3):754–60. 79. Krivokapich J, Child JS, Walter DO, et al. Prognostic value of dobutamine stress echocardiography in predicting cardiac events in patients with known or suspected coronary artery disease. J Am Coll Cardiol. 1999;33(3): 708–16. 80. Poldermans D, Fioretti PM, Boersma E, et al. Long-term prognostic value of dobutamine-atropine stress echo cardiography in 1737 patients with known or suspected coronary artery disease: A single-center experience. Circulation. 1999;99(6):757–62. 81. McCully RB, Roger VL, Mahoney DW, et al. Outcome after normal exercise echocardiography and predictors of subsequent cardiac events: follow-up of 1,325 patients. J Am Coll Cardiol. 1998;31(1):144–9.

CHAPTER 62 Squatting Stress Echocardiography Premindra AN Chandraratna, Dilbahar S Mohar, Peter Sidarous

Snapshot ¾¾ Squatting Echocardiography

INTRODUCTION Regional mismatch between coronary oxygen supply and myocardial demand results in myocardial ischemia. In such ischemic settings, wall motion abnormalities (WMAs) detectable by echocardiography manifest early as diastolic and subsequently systolic changes. Moreover, functional wall abnormalities are early changes in the well-described ischemic cascade, which concludes with later surrogates including electrocardiography (ECG) changes and subsequently overt chest pain.1 As such, stress echocardiography (SE) has an established utility for the detection of significant coronary artery disease (CAD) with a notable accuracy of 80–90%, which is superior to that of exercise electrocardiographic testing and comparable to that of nuclear stress imaging.2 Stress echocardiography is performed either with exercise on a treadmill or bicycle or by infusion of a pharmacological agent such as dobutamine, adenosine, dipyridamole, or transes ophageal atrial pacing. Each of these techniques has advantages and disadvantages. Treadmill or bicycle exercise echocardiography permits assessment of both myocardial ischemia and functional capacity. However, this technique may have limited echocardiographic utility in patients in whom peak exercise is not attainable or in patients with single vessel or

moderate stenosis.3 Furthermore, WMA in the immediate postexercise period may rapidly resolve in some patients resulting in false-negative studies.4 Patients with comorbid conditions such as intermittent claudication, chronic obstructive pulmonary disease (COPD), and musculoskeletal or joint abnormalities may not be able to achieve the levels of exercise sufficient for the detection of myocardial ischemia. Occasionally, ventricular tachy cardia, ventricular fibrillation, myocardial infarction, or death may occur during exercise testing.5 Pharmacological stress testing is performed when exercise testing is not feasible or it may be the preferred method of SE in some laboratories. Moreover, the 2011 American Society of Echocardiography (ASE) Appropriate Use Guidelines for Echocardiography recommend dobut amine as the firstline agent for pharmacologic SE.6 Minor side effects such as chest pain, tremor, palpitations, and dizziness are frequently noted.5 Less commonly, more serious complications such as ventricular or supraventricular tachyarrhythmia, myocardial infarction, or death may occur.7 Although both exercise and pharmacological SE are reliable methods of detecting CAD, the potential for serious side effects, cost, and the time factor are disadvantages of these techniques. Thus, there is the need for a safe, rapid, and inexpensive echocardiographic stress test.

1324


Fig. 62.1: End-systolic frames during standing (left) and squatting (right) in a normal subject. Note the triangular shape of the apex during standing and squatting. (LV: Left ventricle). (Movie clip 62.1). Source: Reproduced with permission from Ref. 10.

SQUATTING ECHOCARDIOGRAPHY Squatting echocardiography has emerged as a promising modality which augments afterload and preload with little or no change in cardiac contractility. Moreover, as afterload and preload are major determinants of myocardial oxygen consumption, patients with significant CAD develop acute WMAs during squatting, which reversibly resolve upon arising. Lewis et al. studied the effects of squatting on hemodynamic parameters and left ventricular (LV) dime nsions in normal subjects.8 They observed that squatting produced increased LV cavity dimensions and increase in mean blood pressure. There was an increase in stroke index and cardiac index. Chandraratna and colleagues have extended previous observations on squatting echocardiography and demon strated that squatting produces LV WMA in patients with CAD.

Squatting Echocardiography Protocol The squatting protocol included recording of the standing (3 minutes of quiet standing) heart rate and blood pressure. Standard parasternal long- and short-axis views and apical two-, three-, and four-chamber views were obtained in the standing position. The positions of the transducer were marked and used for the squatting and dobutamine studies. The subjects were asked to squat for 2 minutes. The body weight was positioned over the heels and the torso maintained in a nearly vertical position. The subjects were instructed to maintain a normal breathing pattern, and the blood pressure, heart rate, and echocardiogram were recorded. The subjects were then asked to stand up and the above parameters were repeated. A 16-segment model

Fig. 62.2: Echocardiogram of a patient with left ventricular (LV) function normal in the standing position. The LV apex had a triangular appearance at end-systole. An extensive wall motion abnormality developed during squatting (arrows). The distal posterior septum, apex, and distal posterolateral wall became akinetic, and the distal half of the LV became dilated. The wall motion abnormalities and the acute left ventricular remodeling (AVLRM) normalized on standing. (Movie clip 62.2). Source: Reproduced with permission from Ref. 10.

was used for analysis of echocardiographic images. A squatting stress echocardiogram was considered positive if there was a new or worsening WMA during squatting. An isolated fixed WMA was not considered a positive result.

Squatting Echocardiography: Results/Observations Squatting Induces LV WMA in Areas Subtended by Stenotic Coronary Arteries The study populations consisted of 15 normal male subjects (Group 1) and 42 males subjects (Group 2) who had coronary angiography.9 Each patient underwent squatting echocardiography testing as per protocol, and standard echocardiographic views were attained and interpreted by an expert echocardiography reader blinded to angiographic results. Group 1 subjects had normal LV global and regional function while standing. There were no WMA while squatting (Fig. 62.1 and Movie clip 62.1). In Group 2, five patients had a baseline WMA. New or worsening WMA occurred during squatting in 35 patients. Twelve patients developed a WMA in the left anterior descending coronary artery territory, five had WMA in the circumflex coronary artery territory, seven had WMA in the right coronary artery territory, and seven had normal wall motion. Eleven had WMA in multiple territories (Fig. 62.2 and Movie clip 62.2). All WMA resolved on standing within 1 min. None of these patients developed chest pain, arrhythmias, or hypotension.

Chapter 62: Squatting Stress Echocardiography

1325

(≥ 90% stenosis). Six subjects in Group 2 had LMCAS and none had severe 3-vessel disease (p < 0.05 vs Group 1 for LMCAS and/or 3-vessel disease). In Group 3, eight had LMCAS and none had severe 3-vessel disease (p < 0.0001 vs Group 1). These observations suggest that patients who develop ALVRM during squatting have severe CAD and should be considered for urgent revascularization therapy.

A

B

Figs 62.3A and B: (A) Apical four-chamber, end-systolic frame in a patient with severe 3-vessel disease obtained in the standing position. Note that the apex is triangular; (B) Apical four-chamber, end-systolic frame during squatting. There is marked dilatation of the distal half of the left ventricle (LV). The arrows indicate the extent of the wall motion abnormality. (Movie clip 62.3). Source: Reproduced with permission from Ref. 10.

The sensitivity, specificity, and accuracy of squatting echocardiography for diagnosis of the CAD were 92%, 80%, and 91%, respectively. In summary, the study showed that squatting induces LV WMA in areas subtended by stenotic coronary arteries.

Patients Who Exhibit Acute LV Remodeling (ALVRM) on Squatting Have Severe CAD It was previously demonstrated that squatting induces LV WMA in areas subtended by stenotic coronary arteries.9,10 In addition, it was observed that some subjects developed acute changes in LV shape (ALVRM) during squatting. Ninety-six subjects were divided into three groups. Group 1 consisted of 12 subjects who developed squattinginduced ALVRM with apical and distal posterior septal akinesis, dilation of the apex, and marked LV shape change at end-systole (Figs 62.2 and 62.3; Movie clips 62.2 and 62.3). Group 2 consisted of 20 subjects with distal posterior septal and apical akinesis without ALVRM, during squatting. Group 3 consisted of 64 subjects who developed WMA in areas other than the apex (n = 49), or normal wall motion (n = 15) during squatting. Coronary angiography in Group 1 revealed that six subjects had left main coronary artery stenosis (LMCAS ≥ 50%), two had severe 3-vessel disease (≥ 90% stenosis), and one had 100% left anterior descending coronary artery occlusion. Severe CAD was defined for purpose of this study as the presence of LMCAS, or severe 3-vessel disease

Comparison of Squatting SE and Dobutamine SE for the Diagnosis of CAD11 Thirty-nine patients scheduled to have coronary angio graphy for the evaluation of chest pain were included in the study. Each patient had squatting SE followed by dobutamine SE. For squatting SE, the echocardiogram in standard views was recorded in the standing position. The procedure was repeated during squatting for 2 minutes. Dobutamine echocardiography was performed using standard protocol. Hemodynamic response to both squatting and dobut amine are compared in Table 62.1. During squatting, new or worsening WMA developed in 20 patients. Six patients developed WMA in the left anterior descending (LAD) territory, three in the circumflex territory, three in the RCA territory, and eight in multiple coronary territories (Movies clips 62.4 to 62.6). The sensitivity, specificity, and accuracy of squatting echocardiography for the diagnosis of CAD were 95%, 94%, and 94%, respectively. For dobutamine SE, the sensitivity, specificity, and accuracy for the diagnosis of CAD were 85%, 94%, and 90%, respectively. There was no significant difference between squatting and dobutamine SE for the diagnosis of CAD (p = .702). These data indicate that squatting and dobutamine echocardiography are equally useful in the diagnosis of CAD.

Mechanism of Squatting-Induced WMA Although the mechanism by which squatting induces WMA is uncertain, a potential mechanism is unmasking of subclinical segmental dysfunction in normokinetic segments subtended by stenotic coronary arteries. Yuda et al.12 have demonstrated subclinical LV dysfunction in patients with CAD and normal ejection fraction. A second more likely mechanism is the induction of myocardial ischemia as squatting increases myocardial oxygen consumption by increasing stroke volume via augmentation of preload and afterload.

1326


Table 62.1: Heart Rate and Blood Pressure Response to Squatting versus Dobutamine11

Total Cohorts

Standing

Squatting

p-value Standing versus Squatting

Dobutamine

p-value Squatting versus Dobutamine

Heart rate (beats/min)

64 ± 10

73 ± 10

<0.0001

123 ± 18

<0.0001

Systolic blood pressure (mm Hg)

121 ± 11

136 ± 11

<0.0001

159 ± 23

<0.0001

Diastolic blood pressure (mm Hg)

79 ± 6

86 ± 7

<0.001

88 ± 10

<0.001

Source: Reprinted with permission from Chandraratna PA, Kuznetsov VA, Mohar DS, et al. Comparison of squatting stress echocardiography and dobutamine stress echocardiography for the diagnosis of coronary artery disease. Echocardiography. 2012; 29(6):695–9.

Advantages Furthermore, there are numerous advantages to squatting as a stress test. The absence of marked changes in heart rate during squatting makes comparison with the baseline echocardiogram and interpretation of stress-induced WMA easier than when tachycardia is present. Ventricular dilatation that occurs with squatting facilitates analysis of wall motion. The rapid recovery of wall motion after squatting reduces adverse sequelae. No ventricular arrhythmias, chest pain, or hypotension were noted during squatting. Additionally, the lack of prominent and sustained heart rate and blood pressure increases, which are known characteristics of other stress imaging such as dobutamine or treadmill testing, further validates squat echocardiography as a safer modality with fewer adverse risks.

Limitations There are some limitations to squatting as a stress test. Patients with knee or hip disease or extreme obesity may not be able to squat. The sonographer also has to squat during the procedure, and only those with adequate echocardiography windows are suitable for testing. Squatting SE possesses similar limitations as com pared to treadmill testing with respect to obesity and orthopedics. However, unless patients have morbid obesity or advanced orthopedic restrictions, squat imaging is still attainable with limited effort as squatting is essentially a static position. The same cannot be said for treadmill testing in which certain heart rate and blood pressure end point parameters need to be achieved for proper treadmill assessment.

CONCLUSION In patients with significant CAD, squatting echocar diography has emerged as a unique stress modality, which

may be used as an adjunct to or independent of current noninvasive stress techniques to risk stratify patients with CAD. Moreover, squatting SE has been identified as an inexpensive, simple, and rapid noninvasive CAD risk assessment modality with fewer complications than current stress imaging techniques.

REFERENCES 1. Nesto RW, Kowalchuk GJ. The ischemic cascade: temporal sequence of hemodynamic, electrocardiographic and symptomatic expressions of ischemia. Am J Cardiol. 1987; 59(7):23C–30C. 2. Marwick TH. Stress echocardiography. Heart. 2003;89(1): 113–18. 3. Marwick TH, Nemec JJ, Pashkow FJ, et al. Accuracy and limitations of exercise echocardiography in a routine clinical setting. J Am Coll Cardiol. 1992;19(1):74–81. 4. Sicari R, Nihoyannopoulos P, Evangelista A, et al; European Association of Echocardiography. Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC). Eur J Echocardiogr. 2008;9(4):415–37. 5. Mertes H, Sawada SG, Ryan T, et al. Symptoms, adverse effects, and complications associated with dobutamine stress echocardiography. Experience in 1118 patients. Cir culation. 1993;88(1):15–19. 6. Douglas PS, Garcia MJ, Haines DE, et al. ACCF/ASE/ AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Society of Echocardiography, American Heart Association, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomo graphy, Society for Cardiovascular Magnetic Resonance American College of Chest Physicians. J Am Soc Echo cardiogr. 2011;24(3):229–67.

Chapter 62: Squatting Stress Echocardiography

7. Picano E, Mathias W Jr, Pingitore A, et al. Safety and tolerability of dobutamine-atropine stress echocar diog raphy: a prospective, multicentre study. Echo Dobutamine International Cooperative Study Group. Lancet. 1994; 344(8931):1190–2. 8. Lewis BS, Lewis N, Gotsman MS. Effect of standing and squatting on echocardiographic left ventricular function. Eur J Cardiol. 1980;11(6):405–12. 9. Chandraratna PA, Maraj R, Tabel G, et al. Left ventricular wall motion abnormalities induced by squatting: a new echocardiographic stress test for the diagnosis of coronary artery disease. J Am Coll Cardiol. 2005;46(5):931–3.

1327

10. Chandraratna PA, Mohar DS, Sidarous PF, et al. Implications of acute left ventricular remodeling during squatting stress echocardiography. Echocardiography. 2012;29(6):700–5. 11. Chandraratna PA, Kuznetsov VA, Mohar DS, et al. Comparison of squatting stress echocardiography and dobutamine stress echocardiography for the diagnosis of coronary artery disease. Echocardiography. 2012;29(6): 695–9. 12. Yuda S, Fang ZY, Marwick TH. Association of severe coronary stenosis with subclinical left ventricular dysfunction in the absence of infarction. J Am Soc Echocardiogr. 2003;16(11):1163–70.

CHAPTER 63 Three-Dimensional Stress Echocardiography Rajesh Ramineni, Masood Ahmad

Snapshot ¾¾ Two-Dimensional Stress Echocardiography ¾¾ Three-Dimensional Transducers ¾¾ Advantages of Three-Dimensional in Stress Imaging ¾¾ Three-Dimensional Image Acquisition ¾¾ Three-Dimensional Stress Protocol ¾¾ Postacquisition Analysis ¾¾ Review of Studies Comparing Three-Dimensional Stress

¾¾ Differences Between 2DSE and 3DSE in Wall

Visualization ¾¾ Parametric Imaging in Three-Dimensional Stress

Echocardiography ¾¾ Role of Contraction Front Mapping in RT3DSE ¾¾ Contrast in Three-Dimensional Stress Testing ¾¾ Future Directions

Echocardiography to Current Standards

INTRODUCTION Stress testing has been in use for a very long time in the diagnosis of coronary artery disease (CAD), in testing functional capacity, and in assessing prognosis. Stressinduced changes in electrocardiogram were initially used to evaluate ischemia until the introduction of imaging techniques, which offered higher sensitivity and specificity. We reported the use of isometric exercise during M-mode echocardiography in the detection of left anterior descending (LAD) artery disease as far back as 1976.1 The value of treadmill exercise echocardiography in the diagnosis of CAD was subsequently demonstrated.2 A plethora of reports on the use of stress echocardiography followed.2–6 Ever since, two-dimensional stress echocardi ography (2DSE) has become an established technique in assessing patients with CAD. Since the stress-induced transient left ventricular (LV) wall motion abnormality needs to be obtained rapidly,7 the technique of acquiring

two-dimensional (2D) images from multiple windows can be challenging. The likelihood of capture at peak stress is decreased in some patients, thereby reducing sensitivity in the detection of ischemia.8 This creates a role for the application of three-dimensional (3D) imaging during stress.9 3D images can be acquired rapidly from a single acquisition and multiple views of the myocardial segments can be derived from the data set. Thus, three-dimensional stress echocardiography (3DSE) can be performed with a shorter scan time, and the technique does not require a high level of operator skill. In this chapter, we will discuss the evolving technology of 3DSE, describe its current applications, and review major clinical studies to date.10

TWO-DIMENSIONAL STRESS ECHOCARDIOGRAPHY As an established technique in the assessment of patients with CAD, 2DSE is commonly used in many

Chapter 63: Three-Dimensional Stress Echocardiography

A

B

Figs 63.1A and B: 3D transducers. (A) Current three-dimensional (3D) transducer with a smaller footprint; (B) First-generation 3D transducer with a larger footprint.

echocardiography laboratories. It has an estimated sensitivity of 71%, a specificity of 85.7%, and a negative predictive value of 95% for any vessel disease.11 The sensitivity of stress echo is higher for multivessel CAD12 and lower for single vessel disease.13 However, 2DSE has a number of limitations. In addition to the difficulties in obtaining images in a very short time frame, the technique has some intrinsic limitations. 2D planes are not always aligned precisely for accurate comparison of segmental wall motion from baseline to stress. Moreover, apical foreshortening is a major concern, increasing false negatives. With the advent of 3D echocardiography (3DE), many of the limitations of two-dimensional echocardi ography (2DE) are put to rest.14–17 Simultaneous assessment of the LV in multiple planes from one acquisition removes temporal assumptions and improves diagnostic accuracy. A shorter scan time means greater possibility of image acquisition at the target heart rate. Moreover, cropping of the full volume images provides unlimited number of conventional and unconventional views of the LV that cannot be obtained by the standard 2D technique.

THREE-DIMENSIONAL TRANSDUCERS Initial attempts to obtain 3D images were based on reconstruction of multiple 2D images acquired by manually tilting the transducers at various angles around a fixed plane (Figs 63.1A and B). However, the acquisition by

1329

these transducers was extremely time consuming, thereby precl uding their use during stress. The introduction of matrix array transducers revolutionized the image acquisition in 3D. For the first time, the images could be obtained in a true 3D format. The first version of these transducers was designed and described by von Ramm and Smith.18 These transducers had 256 nonsimultaneous firing elements with an achieved frequency of 2.5/3/5 Hz. A pyramidal volume data set was obtained in a heartbeat with a sector angle of 60° × 60°. We had the opportunity to use this transducer during stress and described, for the first time, the application of 3D during stress.8 All of the data could be obtained in a single heartbeat and the images were cropped to display the orthogonal and short-axis views of the LV. Due to the small number of elements in the matrix, the resolution of the images generated with this transducer was somewhat low and the sector angle of 60° × 60° did not accommodate dilated LVs. The latest version of matrix array transducers uses 3,000 to 4,000 elements. This change significantly impr oved the image resolution, penetrability, and side lobe suppression. Moreover, the new transducers are smaller, making it possible to fit the transducer in the rib spaces and acquire images at wider sector angles. These transducers can be used comprehensively for combined 2D and 3D imaging.

ADVANTAGES OF THREEDIMENSIONAL IN STRESS IMAGING With advances in transducer technology and the arrival of matrix array transducers, real time 3D acquisitions (RT3D) became possible and the role of 3DE in stress testing surfaced (Table 63.1).9 Multiple studies have successfully documented the feasibility of performing 3DE during dobutamine and exercise stress testing. Although there are variations from vendor to vendor, generally, fullvolume acquisitions of the LV are used for stress testing that are obtained over a span of three to four cardiac cycles. Data can be obtained with a single cardiac cycle as well; however, the volume rate may be limited at high heart rates. With one of the major limitations of 2DE being the inability to obtain images in multiple planes in a very short time period at peak stress, acquisition of full-volume image with a maximum of four cardiac cycles places RT3D at an advantage. In our laboratory, we demonstrated that RT3D data during dobutamine stress echocardiography (DSE) can be obtained in less than half the time needed

1330


Table 63.1: Advantages and Limitations of RT3DSE

Advantages: Shorter acquisition time User-friendly and less operator dependent Good interobserver agreement. Reproducible Precise alignment/anatomically correct tomographic section. More accurate comparison of matched rest and stress images Full-volume acquisition of entire true LV. Multiple sections of the LV and apical region essentially eliminate problems related to off-axis image acquisition or LV foreshortening Quantitative. Assessment of LV volume and EF comparable to CMR Limitations: Lower spatial and temporal (frame/volume rate) resolution especially at peak stress Influenced by respiration, patient motion, and significant variation in heart rate causing image artifacts Suboptimal anterior and lateral wall visualization related to larger transducer footprint Longer offline data analysis time (CMR: Cardiac magnetic resonance; EF: Ejection fraction; LV: Left ventricle).

for 2DE with greater sensitivity validated by cardiac catheterization.8 These data are replicated in multiple other studies.19–27 The 3D data set obtained during the brief acquisition period can be cropped and processed to assess wall motion at rest and peak stress. Misaligned 2D images can lead to erroneous estimation of LV wall motion. This is overcome in RT3D by properly aligning the LV along its long axis so that the true apex of the LV is displayed. Even though, at this time, the image resolution in 2DE is superior to 3DE, the current advances in transducers make it possible to acquire full volume data set at a high volume rate (40 volumes/s) resulting in diagnostic images in the vast majority of patients. 3D imaging is quantitative and can assess LV volumes as well as LV ejection fraction with accuracy comparable to cardiac magnetic resonance imaging, which is an additional benefit in stress imaging to identify transient ischemic dilatation.28,29

THREE-DIMENSIONAL IMAGE ACQUISITION The introduction of matrix array transducers and parallel processing allowed real time acquisition of 3D images as opposed to reconstruction from spatially oriented and sequentially obtained 2D images. Initially, the matrix array had 256 elements that generated a 60° × 60° pyramidal volume. Although the stress images had limited resolution, the ability to obtain multiple views in either orthogonal

(multiplane) or in short-axis (multislice) views from a single data set was truly impressive and obviated the need for multiple acquisitions from multiple windows. The new matrix array transducers have 3,000 to 4,000 elements in the matrix, resulting in higher imaging quality. Using Philips iE33 (Philips Medical Systems, Bothell, WA), RT3D images can be obtained in three different modes. They are live 3D, zoom, and wide angle with their respective angles being 50° × 30°, 30° × 30°, and 90° × 90°. Live 3D images can be obtained within a single heartbeat. This the most common mode of RT3D used for structural assessment of the heart. When a more focused zone needs further detailed exam such as valvular abnormalities, the zoom mode is used. This mode has greater detail at the expense of providing information about a smaller area. A wide angle image is obtained by merging four small pyramids. These separate pyramids are obtained in consecutive beats by ECG gating. Due to a wider sector angle, more volume is captured in this mode making it the mode of choice in stress imaging. However, intrinsic to the use of information from multiple beats, arrhythmias, stitch artifacts, and motion artifacts pose a limitation to this mode, some of which can be overcome by holding breath during acquisition. In patients with arrhythmias, the artifacts can be further reduced by decreasing the number of beats in the full-volume acquisition. The 3D data set can be cropped to display any number of conventional and nonconventional views of the LV for a more thorough assessment of wall motion. The images can be aligned


along the true long axis of the LV for a superior assessment of the true LV apex. With recent developments in 3D software, high-quality, single-beat 3D acquisitions can be obtained at good volume rates of 30–40 frames per second.

THREE-DIMENSIONAL STRESS PROTOCOL The early versions of the 3D equipment lacked combined 2D and 3D imaging. Therefore, in order to obtain 2D and 3D images at baseline and at peak stress, the transducers had to be switched to obtain both sets of images. With the newer systems, the transducers have both 2D and 3D imaging capabilities. Both sets of images can also be obtained by simply switching the acquisition modes. Alternatively, all 2D images can be derived from the 3D data set. The protocol for imaging 3D data sets with routinely performed 2D stress imaging remains variable from laboratory to laboratory. Our approach is to use an integrated 2D/3D stress protocol that includes 3D images in the standard 2D stress imaging protocol. Essentially, 3D full-volume acquisitions are obtained at baseline after capturing standard 2D images from multiple windows. At this time, we obtain 3D acquisitions from the apical and parasternal windows. These steps are repeated at peak stress.

POSTACQUISITION ANALYSIS A single, full-volume acquisition of RT3D can be analyzed in various formats. A simultaneous display of major orthogonal views can be created. This is called the multiplane view. We are able to obtain parasternal long- or short-axis or apical four-, two- or three-chamber views by this technique. Multiple short-axis 2D images (nine equidistant images in general) can also be obtained from apex to base. This is called the multislice view. (Movie clips 63.1 to 63.4). Studies have shown that specificity of detection of CAD and accuracy of identifying right coronary lesions were significantly greater with the use of multislice view.26 This advantage was attributed to better visualization of basal wall motion abnormalities and the acquisition of correct short-axis views. This view is also associated with greater reduction in interobserver variances.26 Analysis of the LV wall motion can be done by the 16- or 17-segment model as recommended by the ASE. The images are analyzed in a complementary fashion;

1331

that is, if a wall motion abnormality is suspected in 2D images but is not entirely clear, 3D images are reviewed for confirmation or exclusion of abnormal wall motion. This integrated approach is very useful in evaluating questionable wall motion changes. In some patients, when the LV is foreshortened in 2D images, 3D images are aligned along the true long-axis of the LV and the apex is carefully examined for wall motion abnormalities (WMA) (Movie clips 63.5 and 63.6). Quantitative data regarding LV volumes and LV ejection fraction are available from the 3D images. Improvements in software used in postac quisition analysis are making it possible to perform a sideby-side synchronized analysis of anatomically aligned 3D DSE data sets resulting in better interobserver agreement.26 In selected patients, we have used contraction front mapping (parametric imaging) in assessing dyssyn chronous LV wall motion induced by ischemia.30 This technique is still evolving and needs further study.

REVIEW OF STUDIES COMPARING THREE-DIMENSIONAL STRESS ECHOCARDIOGRAPHY TO CURRENT STANDARDS Dobutamine Stress Test Given the concern about obtaining good images when patients are hyperventilating postexercise, initial studies comparing the use of 3DE over 2DE for stress testing started with DSE (Table 63.2). Using the first-generation matrix array transducers, we tested for feasibility of RT3DE during DSE and compared its performance to 2DE in 253 patients.8 A subanalysis of correlation with coronary angiograms was done in 90 patients. It was noted that LV wall motion scores were similar with both techniques at rest as well as peak stress, but acquisition of RT3DE was quicker (27.4 ± 10.7 s vs 62.4 ± 20.1 s by 2D with a P < 0.0001). Real time 3D echocardiography was also noted to have higher interobserver agreement for detection of ischemia at peak stress and higher sensitivity in detection of CAD in patients who underwent coronary angiograms. The next major study in this field was unveiled in 2005 when Matsumura et al., compared 2DE to RT3DE during dobutamine stress in 56 patients who previously underwent SPECT due to suspicion of ischemia.24 Similar to our findings they also noted that RT3DE is significantly quicker than 2DE with a success rate comparable to 2DE (92% at rest and 89% at peak stress in RT3DE vs 94% and

1332


Table 63.2: Diagnostic Sensitivity and Specificity of Three-Dimensional (3D) Versus Two-Dimensional (2D) in Detecting Coronary Artery Disease (CAD)

Study (Author, Year, Ref.)

No.

Stress Test (Type)

Validation

Ahmad et al. (2008)

58

DSE

Matsumura et al. (2005)

56

Takeuchi et al. (2006)31

78

Aggeli et al. (2007)

Yoshitani et al. (2009)26

8 24

22

Jenkins et al. (2009)

2D Sen.

Sp.

3D Sen.

Sp.

Coronary angiography

79

—

88

—

DSE

Thalium201-SPECT

86

83

6

80

DSE

None

—

—

58

75

56

DSE


73

78

93

89

71

DSE-3D multiplane


—

—

72

72

DSE-3D multislice


—

—

77

95

Treadmill exercise-2D


83

65

—

—

Treadmill exercise-3D


—

—

40

84

Treadmill exercise-3D+ CFM


—

—

55

78

107

Dipyridamole

None

78

91

80

87

30

Adenosine 2D

Tc 99m Sestamibi SPECT

92

75

—

—

Adenosine Live 3D


—

—

91

69

Adenosine full volume 3D


—

—

90

79

90

32

Badano et al. (2010)21 Abdelmoneim et al. (2010)

33

(CFM: Contraction front mapping; DSE: Dobutamine stress echocardiography; No.: Number of subjects; Sen.: Sensitivity; Sp.: Specificity; SPECT: Single-photon electron-computed tomography; Tc: Technetium).

90%, respectively, in 2DE). The sensitivity, specificity, and accuracy of these two modalities were very similar without any statistical difference when the results of SPECT were used as the reference standard. In the following year (2006), Takeuchi et al. used contrast to enhance the endocardial borders and compared RT3DE with 2DE during DSE for the assessment of WMA in 78 patients with known or suggested history of CAD.31 This study was limited by the fact that it used an earlier generation of bulky transducers with a narrow angle. Levovist (Schering AG, Berlin, Germany) or Optison (Mallinckrodt Inc., St. Louis, MO) /Definity® (Bristol-Myers Squibb, N. Billerica, MA) were used as contrast material in Japan and the United States, respectively, for the included patients. This study used the concept of worsening stressinduced increase in segmental wall motion score index (WMSI) as being suggestive of ischemia. Moreover, they assessed for regional wall motion in each coronary artery territory by predefining segments into major coronary arterial territories. Nine segments (basal anteroseptal, basal anterior, mid-interventricular septum, midanteroseptal, mid-anterior, and four apical) were assigned to the LAD coronary artery territory, three segments (basal

inferior, mid-inferior, and basal interventricular septum) were assigned to the right coronary artery territory, and four segments (basal lateral, basal posterior, mid-lateral, and mid-posterior) were assigned to the left circumflex coronary artery territory. It was noted that a large number of segments were uninterpretable with 3D DSE in comparison to 2D DSE, the majority of which were in anterior and lateral walls. Despite a significant correlation of WMSI between these two modalities, the concordance rates were only moderate. The bulk of the transducer limiting visualization of the anterolateral segments and the low frame rate causing erroneous diagnosis of dyssynchrony were the likely limitations of this study. Using 2D DSE results as the gold standard in this study, the sensitivity and specificity for detecting WMA by 3D DSE were 58% and 75%, respectively. Sensitivity and specificity values were 67% and 94% for the right coronary artery, 53% and 81% for the LAD, and 88% and 100% for the left circumflex coronary artery territory, respectively. In 2007, Aggeli et al. designed a study in close comp arison to ours but with newer generation 3D transducers. Real time 3D echocardiography with 2DE during DSE were compared in 56 patients and validated with results


from coronary angiography.22 They also showed that acquisition time for RT3DE was significantly less (< 50%) when compared to 2DE. Both the modalities showed excellent agreement in WMSI at rest, but at peak stress RT3DE showed significantly higher values. A regional wall motion score of the apical segments (apWMS) was done to delineate differences between the modalities, since 2DE is known to have limitations in accurate evaluation of the apex. RT3DE showed significantly higher wall motion scores at peak stress and higher sensitivity in the LAD territory. The study concluded that the diagnostic value of RT3DE is at least equivalent to 2DE during DSE and, in addition, serves the advantage of markedly shorter acquisition times. Better assessment of apical segments is an added advantage. Overall, the studies using dobutamine as the stress agent showed that 3DSE significantly reduces the time needed for imaging and the WMSI was higher. There was also better interobserver agreement with 3DSE.

Dobutamine Stress Test with Multiplane versus Multislice Imaging Yoshitani et al., in a study which included 71 patients with known or suspected CAD, compared the use of multiplane versus multislice modes in the assessment of wall motion from data obtained using RT3DE.26 Data sets were acquired using a wide-angle (60° × 60°) acquisition mode, in which four wedge-shaped subvolumes (60° × 15° each) were obtained from four consecutive cardiac cycles during held breath. Multiplane mode provided simultaneous visualization of parasternal long- and shortaxis views or apical four-, two-, and three-chamber views whereas nine equidistant 2D short-axis images from LV base to apex were extracted and simultaneously displayed comprising the multislice mode. Wall motion score was obtained by visual assessment of these views, which were then compared against the findings obtained from a coronary angiogram performed the next day in which a luminal narrowing of greater than 50% was considered as significant stenosis. It was noted that, unlike the biplane mode where there was no change in the number of uninterpretable segments from rest to peak stress, these numbers significantly dropped in the multislice mode. The majority of these uninterpretable segments were noted in the anterior and lateral walls in both modes. In contrast to absence of differences at rest, WMSI was significantly lower at peak stress in the multiplane mode compared

1333

with the multislice mode. On a patient basis, sensitivity was not different, but specificity was significantly higher in the multislice mode (95%) compared with the multiplane mode (77%, P < 0.05). Diagnostic accuracy for detecting right CAD was also significantly higher in the multislice mode (93% vs 80%, P < 0.05).

Treadmill Exercise Stress Test In 2009, Jenkins et al studied the feasibility of treadmill exercise stress testing and compared 2DE against 3DE.32 Initially starting the study with 110 patients, the final analysis was done on 90 patients with 20 excluded (12 for nondiagnostic stress and 8 for poor quality 3DE). Unlike the studies done using dobutamine, there was no significant benefit in the acquisition time for 3DE in this study. This study also involved an arm which uses 3DE with contraction front mapping (CFM), which is discussed in detail later in the chapter. The sensitivity of wall motion assessment with 3DE (40%) was noted to be lower than 2DE (83%, P < 0.01) at comparable levels of specificity (65% and 78%). However, the combined use of 3DE along with CFM added to the sensitivity and overall accuracy. This study was noted to be different on many fronts. The average time taken to acquire 3D images was longer than the previous studies with a possible impact on the outcomes. 3D echocardiography images were obtained on an average of 58 (± 25) seconds after the patient was off the treadmill, which brings into question the ability to get images at target heart rate. Moreover, contrast agents were not used to enhance the endocardium. These limitations, in addition to this being the only study available using exercise as stress technique, make it difficult to draw conclusions.

Adenosine Stress Test Abdelmoneim et al., in a study involving 30 patients, compared 3DE (full volume and live 3D) to 2DE and the standard SPECT imaging to evaluate for CAD.33 Sensiti vities and specificities were corelated between these three modalities. Adenosine was administered as the stress agent and contrast (Definity®) was used for all echocardio graphic studies. It was noted that live 3D identified abnormalities in areas with reversible defects in SPECT in 88% versus 63% with full-volume 3D images. This was the first attempt comparing 3D and 2D contrast echocardiography in the evaluation of perfusion defects with SPECT as the diagnostic standard. However, a

1334


et al. the use of 3DSE was also associated with greater sensitivity and specificity in assessing the lateral LV wall, which plays a role in its detection of isolated left circumflex lesions.31 However, due to the greater resolution of 2DE, good views of the basal structures were obtained with 2DE during stress testing.

A

B

Figs 63.2A and B: Segmental time–volume curves of a patient who underwent three-dimensional stress echocardiography (3DSE) and contraction front mapping (CFM). (A) At baseline, synchronous time–volume curves are seen suggesting uniform myocardial segmental contraction; (B) At peak stress, time–volume curves are dyssynchronous with nonuniform segmental contraction suggesting reversible ischemia.

limitation of this study was a lack of comparison with coronary angiography in patients with reversible perfusion defects.

Dipyridamole Stress Test Badano et al., with the newer high-volume rate scanners with higher temporal resolution and the possibility of displaying cropped images side by side, compared RT3DE with 2DE during dipyridamole-induced stress (DipSE) in 84 patients.21 The results of this study were consistent with the other dobutamine-based studies reviewed earlier, with RT3DE displaying significantly lower acquisition times, higher WMSI at peak stress (more so in the apical regions), and better sensitivity in the LAD territory as noted in patients who underwent coronary angiograms. Interestingly, the postacquisition analysis time, which in general was assumed to be longer in RT3DE, was also significantly shorter in RT3DE than in 2DE. However, the temporal resolution was significantly better in 2DE (75 ± 5 frames/s vs 41 ± 5 volumes/s, respectively; P < 0.0001).

DIFFERENCES BETWEEN 2DSE AND 3DSE IN WALL VISUALIZATION One of the major limitations of 2DSE is its inability to open up the entire LV apex (LV foreshortening), thus generating a possibility of error in assessment of wall motion. Aggeli et al. showed that 3DSE predicted a higher wall motion score predominantly in the LV apex, which corresponded with ischemia in LAD territory,22 as seen in the reference standard (coronary angiography). As shown by Takeuchi

PARAMETRIC IMAGING IN THREEDIMENSIONAL STRESS ECHOCARDIOGRAPHY As an alternative to wall motion assessment, parametric imaging can be applied in analysis of 3D stress data (Figs 63.2A and B). Segmental time–volume curves and contraction front maps can be generated from the acquired 3D data sets. Temporal heterogeneity of myo cardial contraction induced by stress can be measured by the dyssynchrony index similar to the evaluation of mechanical dyssynchrony in patients with LV dysfunction for cardiac resynchronization therapy. Segmental time to minimal systolic volume can be displayed at baseline and at peak stress. Stress-induced ischemia will result in delayed contraction in ischemic segments thus resulting in dyssynchrony.

ROLE OF CONTRACTION FRONT MAPPING IN RT3DSE Contraction front mapping (TomTec Imaging Systems, Munich, Germany) analyzes temporal and spatial activ ation of LV contraction and displays a bull’s-eye plot of the contraction wave front of the myocardial segments that reach peak contraction every 25 milliseconds (Movie clips 63.7 and 63.8). Color-coded maps show the contraction wave in blue and the noncontracting segments in shades of red. Thus, increasing degrees of dyssynchrony induced by ischemia are displayed in shades of red. Contraction front mapping also has the potential to provide quantitative analysis of LV contraction through assessment of time to minimal volume, aiding in the diagnosis of segm ental ischemia. Contraction front mapping might be applicable as a good qualitative and quantitative tool in the assessment of ischemia as noted in its initial application described from our laboratory.30 Jenkins et al., in their study done on treadmill exercise stress test, compared 2DE against 3DE as well as 3DE with CFM.32 CFM was done offline from the 3DE full-volume data. After defining normal cutoff ranges for contraction delay based on receiver-operating characteristics, they noted that the concordance between angiography and


qualitative CFM (63%) was similar to quantitative CFM (70%). Moreover, it was noted that the combined use of 3DE along with CFM added to the overall sensitivity (improved from 40% to 55%), specificity (improved from 65% to 84%), and accuracy of 3DSE. The limitations of this study were discussed earlier.

CONTRAST IN THREE-DIMENSIONAL STRESS TESTING Given the limited resolution of 3D when compared to 2D, use of contrast agents to improve the visualization of the endocardial border makes theoretical sense. Pulerwitz, in an initial study of 14 patients, noted that ultrasound contrast significantly increased the proportion of segments adequately visualized during rest and peak dobutamine infusion (91%–98%, P = 0.001, and 87%–99%, P = 0.001, respectively).16 There was almost complete concordance between observers (96.9% at rest and 98.2% at peak stress with almost no interobserver variability), whereas noncontrast studies had much lower agreement (84.4% at rest and 79.9% at peak stress with kappa values less than 0.4). Nemes et al. in 2007, studied the use of contrast in 36 patients undergoing routine stress test for stable chest pain.34 The images obtained with and without contrast were compared for image quality index, and wall motion was assessed using the standard 17-segment LV model. It was noted that myocardial segment visualization improved from 76% to 90% with the use of contrast, and the image quality index improved from 2.2 to 3.1. Agreement on coronary territory of ischemia improved from 79% to 88%. Study agreement on myocardial ischemia also improved from 72% to 89%. However, this study used the larger transducer (X4 24 × 20 mm) with a bigger footprint resulting in less favorable outcome with the use of conventional RT3DE.

FUTURE DIRECTIONS Further developments in transducer technology and processing techniques should allow 3D acquisitions at higher volume rates at high heart rates during stress. Single beat acquisitions of full volumes will avoid the potential for artifacts. Automated software for side-by-side display of baseline and stress 3D images will facilitate interpretation of 3DSE. Parametric imaging may provide an entirely new approach in mapping ischemic regions of the left ventricle. These developments should

1335

allow assessment of the LV with 3D during stress without the need for concurrent conventional 2D imaging. Automated fused stress image technique is another modality which might prove to be beneficial in the future. This method incorporates RT3D echocardiography with myocardial perfusion SPECT imaging to create a fused image which had excellent specificity and sensitivity in detecting myocardial ischemia with low interobserver variability in a study by Walimbe et al.35 They studied 20 patients with 36 angiographically evaluated coronary arteries. This was a pilot study with a small number of subjects. More studies with greater power are needed to evaluate its feasibility and confirm these findings.

CONCLUSION 3DSE is an exciting technology that is rapidly evolving and currently applied as an adjunctive technique to 2DSE. The availability of 3D images is tremendously useful in evaluating questionable areas of abnormality seen in 2DSE and in more accurately assessing the changes induced by ischemia.36 In the near future, 3DSE may be applied independent of the traditional 2DSE resulting in a comprehensive diagnostic stress test that is more efficient, quantitative, and reproducible in the diagnosis of CAD.

REFERENCES 1. Ahmad M, Watson, LE. Application of stress echocardi ography in the diagnosis of left anterior descending coronary artery disease. Clin Res. 1976;515A. 2. Maurer G, Nanda NC. Two dimensional echocardiographic evaluation of exercise-induced left and right ventricular asynergy: correlation with thallium scanning. Am J Cardiol. 1981;48(4):720–7. 3. Innocenti F, Caldi F, Tassinari I, et al. Prognostic value of exercise stress test and dobutamine stress echo in patients with known coronary artery disease. Echocardiography. 2009;26(1):1–9. 4. Olmos LI, Dakik H, Gordon R, et al. Long-term prognostic value of exercise echocardiography compared with exercise 201Tl, ECG, and clinical variables in patients evaluated for coronary artery disease. Circulation. 1998;98(24):2679–2686. 5. Marwick TH. Stress echocardiography. Heart. 2003;89(1): 113–8. 6. Abreo G, Lerakis S, Ahmad M. Use of exercise echocardio graphy to evaluate patients with chest pain. Am J Med Sci. 1998;316(5):345–50. 7. Armstrong WF, Pellikka PA, Ryan T, et al. Stress echocardiography: recommendations for performance and interpretation of stress echocardiography. Stress Echocar diography Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography. J Am Soc Echocardiogr. 1998;11(1):97–104.

1336


8. Ahmad M, Xie T, McCulloch M, et al. Real-time threedimensional dobutamine stress echocardi ography in assessment stress echocardiography in assessment of ischemia: comparison with two-dimensional dobutamine stress echocardiography. J Am Coll Cardiol. 2001;37(5): 1303–9. 9. Ahmad M. Real-time three-dimensional echocardiography in assessment of heart disease. Echocardiography. 2001; 18(1):73–7. 10. Abusaid GH, Ahmad M. Real time three-dimensional stress echocardiography advantages and limitations. Echocardi ography. 2012;29(2):200–6. 11. Afridi I, Quiñones MA, Zoghbi WA, et al. Dobutamine stress echocardiography: sensitivity, specificity, and predi ctive value for future cardiac events. Am Heart J. 1994; 127(6):1510–15. 12. Roger VL, Pellikka PA, Oh JK, et al. Identification of multivessel coronary artery disease by exercise echocar diography. J Am Coll Cardiol. 1994;24(1): 109–14. 13. Marwick TH, Nemec JJ, Pashkow FJ, et al. Accuracy and limitations of exercise echocardiography in a routine clinical setting. J Am Coll Cardiol. 1992;19(1):74–81. 14. Pandian NG, Roelandt J, Nanda NC, et al. Dynamic threedimensional echocardiography: methods and clinical potential. Echocardiography. 1994;11(3):237–59. 15. Wang XF, Deng YB, Nanda NC, et al. Live three-dimensional echocardiography: imaging principles and clinical application. Echocardiography. 2003;20(7):593–604. 16. Pulerwitz T, Hirata K, Abe Y, et al. Feasibility of using a realtime 3-dimensional technique for contrast dobutamine stress echocardiography. J Am Soc Echocardiogr. 2006;19(5): 540–5. 17. Takuma S, Cardinale C, Homma S. Real-time three-dime nsional stress echocardiography: a Review of current applications. Echocardiography. 2000;17(8):791–4. 18. von Ramm OT, Smith SW. Real time volumetric ultrasound imaging system. J Digit Imaging. 1990;3(4):261–6. 19. Pratali L, Molinaro S, Corciu AI, et al. Feasibility of realtime three-dimensional stress echocardiography: pharma cological and semi-supine exercise. Cardiovasc Ultrasound. 2010;8:10. 20. Varnero S, Santagata P, Pratali L, et al. Head to head comparison of 2D vs real time 3D dipyridamole stress echocardiography. Cardiovasc Ultrasound. 2008;6:31. 21. Badano LP, Muraru D, Rigo F, et al. High volume-rate threedimensional stress echocardiography to assess inducible myocardial ischemia: a feasibility study. J Am Soc Echoc ardiogr. 2010;23(6):628–35. 22. Aggeli C, Giannopoulos G, Misovoulos P, et al. Real-time three-dimensional dobutamine stress echocardiography for coronary artery disease diagnosis: validation with coronary angiography. Heart. 2007;93(6):672–5. 23. Nemes A, Leung KY, van Burken G, et al. Side-byside viewing of anatomically aligned left ventricular segments in three-dimensional stress echocardiography. Echocardiography. 2009;26(2):189–95. 24. Matsumura Y, Hozumi T, Arai K, et al. Non-invasive assessment of myocardial ischaemia using new real-time

three-dimensional dobutamine stress echocardiography: comparison with conventional two-dimensional methods. Eur Heart J. 2005;26(16):1625–32. 25. Yang HS, Pellikka PA, McCully RB, et al. Role of biplane and biplane echocardiographically guided 3-dimensional echocardiography during dobutamine stress echocardi ography. J Am Soc Echocardiogr. 2006;19(9): 1136–43. 26. Yoshitani H, Takeuchi M, Mor-Avi V, et al. Comparative diagnostic accuracy of multiplane and multislice threedimensional dobutamine stress echocardiography in the diagnosis of coronary artery disease. J Am Soc Echocardiogr. 2009;22(5):437–42. 27. Zwas DR, Takuma S, Mullis-Jansson S, et al. Feasibility of real-time 3-dimensional treadmill stress echocardiography. J Am Soc Echocardiogr. 1999;12(5):285–9. 28. Qi X, Cogar B, Hsiung MC, et al. Live/real time threedimensional transthoracic echocardiographic assessment of left ventricular volumes, ejection fraction, and mass compared with magnetic resonance imaging. Echocardi ography. 2007;24(2):166–73. 29. Macron L, Lim P, Bensaid A, et al. Single-beat versus multibeat real-time 3D echocardiography for assessing left ventricular volumes and ejection fraction: a comparison study with cardiac magnetic resonance. Circ Cardiovasc Imaging. 2010;3(4):450–5. 30. Ahmad M, Dimaano M, Xie C. Abstract 2916: Contraction Front Mapping in Detection of Ischemia during Live 3-Dimensional Dobutamine Stress Echocardiography. Circulation. 2006;114(II_612). 31. Takeuchi M, Otani S, Weinert L, et al. Comparison of contrast-enhanced real-time live 3-dimensional dobuta mine stress echocardiography with contrast 2-dimensional echocardiography for detecting stress-induced wall-motion abnormalities. J Am Soc Echocardiogr. 2006;19(3):294–9. 32. Jenkins C, Haluska B, Marwick TH. Assessment of temporal heterogeneity and regional motion to identify wall motion abnormalities using treadmill exercise stress threedimensional echocardiography. J Am Soc Echocardiogr. 2009;22(3):268–5. 33. Abdelmoneim SS, Bernier M, Dhoble A, et al. Assessment of myocardial perfusion during adenosine stress using real time three-dimensional and two-dimensional myocardial contrast echocardiography: comparison with single-photon emission computed tomography. Echocardiography. 2010; 27(4):421–9. 34. Nemes A, Geleijnse ML, Krenning BJ, et al. Usefulness of ultrasound contrast agent to improve image quality during real-time three-dimensional stress echocardiography. Am J Cardiol. 2007;99(2):275–8. 35. Walimbe V, Jaber WA, Garcia MJ, et al. Multimodality cardiac stress testing: combining real-time 3-dimensional echocardiography and myocardial perfusion SPECT. J Nucl Med. 2009;50(2):226–30. 36. Ahmad M. Real-time three-dimensional dobutamine stress echocardiography: a valuable adjunct or a superior alternative to two-dimensional stress echocardiography? J Am Soc Echocardiogr. 2009;22(5):443–444.

CHAPTER 64 Echocardiographic Assessment of Coronary Arteries—Morphology and Coronary Flow Reserve Karina Wierzbowska-Drabik, Jarosław D Kasprzak

Snapshot  The Assessment of Coronary Morphology and Flow in

 Distal Coronary Flow and Coronary Flow Reserve  Congenital AbnormaliƟes of the Coronary Arteries

Transthoracic and Transesophageal Studies  VisualizaƟon of Coronary Arteries

INTRODUCTION Coronary arteries are visible during standard echocardiographic examination. However, small size and vigorous motion of epicardial coronary segments during respiratory and cardiac cycle pose a significant challenge for all noninvasive imaging methods. Therefore, direct evaluation of coronary arteries has not become a part of routine transthoracic echocardiographic (TTE) examination despite significant technical improvements leading to improved quality of imaging. These limitations are less evident in transesophageal echocardiogram (TEE). Recent progress in Doppler sensitivity encouraged routine use of distal coronary flow velocity and vasodilator-induced velocity reserve measurements.

THE ASSESSMENT OF CORONARY MORPHOLOGY AND FLOW IN TRANSTHORACIC AND TRANSESOPHAGEAL STUDIES Current TTE and TEE allows addressing the following clinical aspects of coronary anatomy and physiology: • Identification of ostia and proximal segments of left and right coronary arteries and diagnosis of congenital

•

•

•

anomalies of their origin by two-dimensional and color Doppler studies Assessment of flow in the main coronary arteries (left main coronary artery (LMCA), circumflex (Cx), left anterior descending (LAD), and right coronary artery (RCA) with possible detection of stenotic flow acceleration and luminal narrowing or aneurysms, for example, in Kawasaki disease in pediatric population Evaluation of accessible parts of mid and distal coronary arteries and the assessment of coronary by-pass grafts (usually internal mammary artery) with assessment of coronary flow velocity reserve (CFVR) based on Doppler recording at rest and under vasodilator stress (with highest feasibility in LAD but examined also in RCA) Diagnosis of coronary fistulas draining to heart chambers and pulmonary artery, which may be often clearly visualized by TTE color Doppler study (Fig. 64.1).

VISUALIZATION OF CORONARY ARTERIES Transthoracic Echocardiography Visualization of proximal segments of coronary arteries is possible in the majority of TTE examinations. Good-

1338


Fig. 64.1: A typical image of proximal coronary arteries in parasternal short-axis view. (Ao: Aorta, LCA: Left coronary artery; RCA: Right coronary artery; RV: Right ventricle).

Fig. 64.2: Additional image of the proximal right coronary artery orifice in parasternal long-axis view. (Ao: Aorta; LV: Left ventricle; RCA: Right coronary artery; RV: Right ventricle).

quality color flow recording in LMCA including proximal Cx and RCA may be obtainable in approximately 55% of cases.1 However, more recent publications report much higher feasibility values2—antegrade LAD flow may be completely seen in >90% of patients, with lower values for the proximal, middle, and distal segments of Cx (88%, 61%, and 3%, respectively) or RCA (40%, 28%, and 54% of patients, respectively). Typically, the coronary ostia are seen in parasternal short-axis views at the level of the sinuses of Valsalva (Fig. 64.1; Movie clip 64.1), with additional views of the right coronary ostium seen in parasternal long-axis view (Fig. 64.2). The perpendicular direction of LMCA in shortaxis view in TTE may cause suboptimal detection of flow with underestimation of recorded flow velocity, thus prompting a search for images from additional window— modified apical five-chamber view (Fig. 64.3). The possibility of transthoracic detection of coronary stenosis was underestimated for years. Recent studies demonstrate that with a careful technique, many major coronary segments can be visualized and a strategy of high sensitivity Doppler detection of stenosis can be adopted in experienced hands.3 Due to anatomical relationships, the easiest recording of coronary flow is that obtained for the proximal LAD and both interventricular branches. The most specific sign of coronary stenosis is flow acceleration and turbulence— thus color Doppler can serve as a roadmap for more detailed spectral flow interrogation both in TTE and TEE studies (Movie clip 64.2). The presence of stenosis with rapid, multidirectional flow may “lighten up” the

flow in the locations where normally no color of spectral coronary flow signal could be recorded. Twofold increase in coronary flow velocity or acceleration of diastolic flow above 2 m/s are specific signs of a significant coronary stenosis or restenosis.3,4 Unfortunately, there are no direct specific signs for the color flow detection of coronary occlusion. In such cases, reversed diastolic flow in coronary arteries depending from retrograde filling by collateral circulation could be recorded. This finding is very specific but offers low sensitivity since collaterals may also provide anterograde perfusion.5 Two-dimensional detection of coronary luminal stenosis is usually not reliable in TTE.

Transesophageal Echocardiography Higher ultrasound beam frequency (thus higher resolution) and anatomical proximity create opportunities for improved imaging of proximal coronary arteries (especially left) from the transesophageal window, including better anatomical definition of possible lesions. TEE enables visualization of proximal coronary arteries in more than 90% of studies and offers interpretable recordings of flow in 85%, 65%, and 58% of LAD, Cx, and RCA , respectively. As opposed to TTE, TEE allows the assessment of vessel morphology including the identification of luminal narrowing.6 Importantly, from the clinical point of view, LMCA is evaluable in nearly in 100% for twodimensional and 88% for flow imaging by experienced observer during TEE study.7 The technique of TEE assessment of coronary ostia is based on the systematic

Chapter 64: Echocardiographic Assessment of Coronary Arteries—Morphology and Coronary Flow Reserve

1339

Fig. 64.3: Additional image of the proximal left coronary artery in modified apical five-chamber view; note red-coded LCA flow with focal turbulence (stenotic site—arrow). (Ao: Aorta; LCA: Left coronary artery; RV: Right ventricle; LV: Left ventricle).

Fig. 64.4: Normal left main coronary artery with bifurcation visualized in transesophageal echocardiography (TEE). (Ao: Aorta; LA: Left atrium; RVOT: Right ventricle outflow tract).

Fig. 64.5: Normal proximal right coronary artery visualized in twoand three-dimensional echocardiography including ostial en-face views and flow recording. (Ao: Aorta; RA: Right atrium; RCA: Right coronary artery; RVOT: Right ventricle outflow tract; LA: Left atrium).

Fig. 64.6: Normal left main coronary artery flow visualized in transesophageal echocardiography (TEE). (Ao: Aorta; RVOT: Right ventricle outflow tract; LCA: Left coronary artery; LA: Left atrium).

visualization of left and right sinus of Valsalva in high esophageal short-axis cross-sectional views (Movie clip 64.3) leading to the identification of LMCA dividing into LAD and Cx (Fig. 64.4), and, usually in separate view, RCA (Fig. 64.5). This approach allows the exclusion of coronary artery anomalies. Usually coronary arteries visualization is accomplished in color flow mode (Fig. 64.6; Movie clip 64.4) with filter setting kept low to enhance low velocity diastolic flow of the coronary arteries. Detection of focal acceleration and aliasing is the typical, highly specific sign of significant luminal stenosis (Figs 64.7 and 64.8). Nyquist limit should be kept high at this stage to avoid false-positive findings of flow acceleration coded by aliased signal. An

attempt to record flow with spectral Doppler should be done, especially when abnormal color pattern is seen (Movie clip 64.5), with LMCA and LAD being most feasible. Measuring diameters is feasible mainly for LMCA and Cx due to the perpendicular course versus TEE ultrasound beam of LMCA to ultrasound beam in both TTE and TEE examination allows its measurement in optimal linear resolution.8 Beyond the search of stenosis, significant dilatation of proximal segment of the coronary artery may be diagnostic for the presence of fistula, aneurysm (atherosclerotic or Kawasaki disease), or anomalous origin of the coronary artery from the pulmonary artery (e.g. White–Bland–Garland syndrome). The progress in

1340


A

B

Figs 64.7A and B: Examples of stenosis in circumflex (Cx; A) and left anterior descending (LAD; B) detected by transesophageal echocardiography (TEE) color Doppler. (Ao: Aorta; RVOT: Right ventricle outflow tract; LCA: Left coronary artery; Cx: Circumflex artery; LAD: Left anterior descending; LA: Left atrium).

color Doppler is close to 100% for LMCA, 95% for LAD, 75% for Cx with much less sensitivity for RCA .11

DISTAL CORONARY FLOW AND CORONARY FLOW RESERVE

Fig. 64.8: Stenotic distal left main artery (LMA) with accelerated flow spectrum recorded by transesophageal echocardiography (TEE). (Ao: Aorta; RVOT: Right ventricle outflow tract; LA: Left atrium; LCA: Left coronary artery).

three-dimensional echocardiography allows registration of high-resolution data sets with unique ostial views and improved tracking of the spatial course of proximal coronary arteries9 (Figs 64.5 and 64.9). Multiplane features of matrix probes are also valuable tools for imaging of rapidly moving objects such as coronary arteries including flow (Movie clip 64.3). Twofold increase in coronary flow velocity (maximalto-prestenotic flow velocity ratio)10 or maximal flow velocity above 1.5 to 2.0 m/s represents a specific threshold for diagnosing significant coronary stenosis, consistent with TTE. Specific velocity thresholds for TEE have also been proposed (Table 64.1). The accuracy for detection of proximal stenosis based on combined two-dimensional,

Due to improving Doppler technology, routine detection of distal coronary flow (apical segments of major epicardial coronary arteries) has become routinely feasible.13 Intravenous contrast agent injection may be useful to enhance low-intensity flow signals.14 Usually, the detection of flow in distal LAD is achieved in modified apical three-chamber view, usually in the range of 20 to 50 cm/s (Fig. 64.10). Increased velocities may occur if a stenotic situs is directly sampled, whereas very low distal velocities (around 10 cm/s) with slow deceleration were reported distally to critical stenoses in LAD. Feasibility of distal LAD Doppler flow recording is higher (90–95%) than in RCA (60–70%) or marginal branches of Cx (main Cx flow registration is not feasible).15 Recording of coronary sinus flow allows insight in the total coronary flow return and TEE approach has been suggested for the diagnosis of LAD stenosis (abnormal value < 2.0)16 or evaluation of microvascular dysfunction in patients with diabetes with proposed cut-off values < 1.7.17 Distal post-stenotic diastolic-to-systolic velocity ratio has been reported as an accurate approach to define significant LAD or marginal branch stenosis (abnormal cutoff < 1.68).18 Early postinfarction resting flow pattern in distal LAD bed was described to predict remodeling and transmural necrosis. Short deceleration time of diastolic


1341

Fig. 64.9: Proximal left coronary artery analyzed in three-dimensional echocardiography including ostial en-face views and multislice imaging. (Ao: Aorta; AV: Aortic valve; RV: Right ventricle; LA: Left atrium; LCA: Left coronary artery). Table 64.1: The Optimal Views for Proximal Segments of Coronary Arteries and Proposed Cut-Off Values for the Assessment of Significant Stenosis

Coronary Artery

TTE-Optimal View

TEE-Optimal View

Proposed Cut-Off Values11

Proposed Cut-Off Values12

LMCA

High parasternal short-axis, apical five-chamber

Short axis, 0° or 180°, 1–2 cm above aortic valve

> 1.23 m/s

> 1.40 m/s

LAD

High short-axis proximal and directed toward the probe, apical five-chamber

Short-axis distal and directed from the probe—near parallel to Doppler beam

> 1.10 m/s

> 0.9 m/s

Cx

High short-axis distal and directed from the probe

Short-axis proximal and directed toward the probe

> 1.40 m/s

> 1.10 m/s

RCA

Parasternal long-axis, parasternal short-axis

Short axis, slightly higher than LMCA ostium and in the aortic long-axis view

> 0.53 m/s

—

(Cx: Circumflex; LAD: Left anterior descending; LMCA: Left main coronary artery; RCA: Right coronary artery; TEE: Transesophageal echocardiography; TTE: Transthoracic echocardiography).

coronary flow (≤600 ms) recorded 2 days after percutaneous coronary intervention (PCI) in the distal part of LAD and intramyocardial arteries predicted the lack of myocardial viability after anterior wall infarction19 and worse clinical outcomes.20 Finally, calculating distal to proximal diastolic velocity ratio was attempted to improve the detection of left coronary artery (LCA) stenosis (normal value < 0.5).21 Measuring resting values alone is subject to many technical inaccuracies and thus velocity ratio approach has become more popular. Technically, sample volume of pulsed wave Doppler should be located distally from the investigated stenosis (which can be localized anywhere proximal to the measurement). The localization of the sample volume in part proximal to stenosis may

provide false-negative results because of the presence of normal side branches between the sampling site and the stenosis. In clinical practice, coronary flow reserve (CFVR) is usually assessed in LAD after flow detection in dedicated color flow mapping protocols from apical foreshortened three-chamber view (with probe located in higher intercostal space). The evaluation of coronary flow reserve (CFVR) in RCA requires recording of flow in distal posterior interventricular artery from a modified apical two-chamber view (Fig. 64.11). Noninvasive evaluation of CFVR in echocardiography allows the assessment of functional significance of the stenosis in epicardial parts of coronary arteries and the status of the microcirculation.22 Distal coronary flow

1342


Fig. 64.10: Distal left coronary artery (LCA) flow recorded in color and spectral Doppler, modified apical four-chamber view. (Ant IVS: Anterior interventricular septum; LCA: Left coronary artery; LV: Left ventricle).

Fig. 64.11: Distal right coronary artery (RCA) flow recorded in color and spectral Doppler, modified apical two-chamber view. (RCA: Right coronary artery; LA: Left atrium).

Table 64.2: The Conditions Decreasing CFR in the Absence of Significant Stenoses in Epicardial Arteries

Hypertrophic cardiomyopathy Hypertrophy in arterial hypertension Aortic stenosis Aortic insufficiency Dilated cardiomyopathy Diabetes Syndrome X Increased blood viscosity: policythemia, macroglobulinemia Hypercholesterolemia For some of these conditions (e.g. aortic valve disease, hypertension, hypercholesterolemia) surgical or medical treatment could reverse coronary flow reserve (CFR) impairment.10

becomes abnormal in cardiac vascular or myocardial disease and resting values have been recently proposed. Relationship of peak diastolic flow velocity during vasodilatory challenge (in practice—usually intravenous dipyridamole or adenosine, which act on precapillary resistance vessels to maximize flow) to resting flow velocity allows to calculate CFVR, closely corresponding with the values provided with intracoronary Doppler measurements and useful to define physiologically meaningful stenosis in LAD and RCA.23 The conditions impairing CFVR values despite normal epicardial arteries in invasive angiography are listed in Table 64.2. CFVR is defined as the ratio of maximal (or mean) velocity of coronary flow measured during vasodilatation (which may be induced medically by dipirydamole, adenosine, dobutamine, or papaverine infusion or by

exercise) to the resting or baseline flow velocity. In practice, the assessment of CFVR is more difficult in the setting of exercise or during dobutamine test (because of tachycardia and increased respiratory motion), and the two methods of choice are studies with dipirydamole (0.84 mg/kg, iv) or adenosine (0.14 mg/kg/min, iv) infusions. Normal values for CFVR range from 3 to 5 and values below 2 confirm the physiological significance of coronary artery stenosis, usually with luminal narrowing > 70% coronary artery stenosis or indicate other conditions impairing CFVR24,25 (Figs 64.12 and 64.13). The assessment of CFR may help in classification of intermediate stenosis (40–70%) to the invasive treatment. CFVR decreases with age, but may exceed 5 in selected groups of patients such as young healthy athletes.26 CFVR also show transmural dispersion, related to greater extravascular component of microcirculatory resistance


1343

to impair CFVR34 and in long-term, an improvement in CFVR was recorded (invasively by intracoronary Doppler) 4 months after stem cell therapy in reperfused acute myocardial infarction comes from REPAIR-AMI trial.35 In the group of 30 patients treated by intracoronary bone marrow cells infusion, coronary flow reserve improved from 2.0 ± 0.1 to 3.8 ± 0.2, as P < 0.001 as compared to controls (change 1.9 ± 0.1 to 2.8 ± 0.2).

CONGENITAL ABNORMALITIES OF THE CORONARY ARTERIES The prevalence of coronary arteries anomalies ranges from about 1 to 5.6% and the most frequent anomaly is the Cx branch originating from the RCA or the right sinus of Fig. 64.12: Normal coronary velocity flow reserve measured in 36–39 distal left anterior descending (LAD)—coronary flow velocity Valsalva, found in 0.48% of the invasive angiographies. The clinical presentation may be silent or they may cause reserve (CFVR) = 3.0. angina, arrhythmia, syncope, myocardial infarction, and 40 in subendocardial layer, with higher CFVR values in sudden cardiac death. Some anomalies of coronary subepicardial than subendocardial regions.27 The value arteries origin including the LMCA arising from the right of adding CFVR (usually LAD) to wall motion assessment sinus of Valsalva (although less common than the origin of lies in improved sensitivity without specificity loss.28 RCA from the left sinus of Valsalva (Fig. 64.14), may have CFVR is recommended as a component of state-of-the- fatal consequences related to slit-like orifice narrowing, art standard stress echo protocol with dipyridamole and sharp angulation, and risk of intra-arterial course between is most practical when clinical questions regarding the the aorta and pulmonary artery, with threatened sudden specific anatomical locations arise. Recently published cardiac death during exercise. The diagnosis of coronary study has shown high accuracy of coronary flow reserve anomalies by echocardiography has been overshadowed < 2 assessed by TTE for the detection of significant by magnetic resonance or computed echocardiography; restenosis after stent implantation, again with cutoff value however, it remains a useful option, is radiation-free, < 2. 0 for three major coronary arteries.29 The diagnostic and allows real-time assessment of coronary anatomy value of TTE coronary flow reserve is high and similar to and flow. While TTE remains challenging in some cases, TEE images usually unveil realistic coronary anatomy. 320-row computed tomography.30 The impairment of coronary flow reserve with cut- Such composite diagnostic approach, including invasive off value < 1.7 assessed during the 24-hour period after coronary angiography or intracoronary ultrasound as primary coronary intervention was also documented necessary, may be necessary to define the exact course of as the predictor of left ventricular remodeling early coronary arteries, elucidate possible pathomechanisms after anterior myocardial infarction.31 Decreased aiding in therapeutic decision-making. This may be coronary flow reserve < 2.6 with shortened < 840 ms especially valuable when overlap of congenital and diastolic deceleration time were also related to higher acquired atherosclerotic coronary disease comes into incidence of cardiac events in patient after heart play.41 Identification of aberrant left coronary artery with transplantation, defined as cardiac death, heart failure, interarterial course alone represents an indication for and stent implantation.32 Reduced long-term survival surgical intervention, whereas in anomalous origin of the was also described in patients with coronary flow reserve RCA more percutaneous interventions may be considered. < 2 in dilated cardiomyopathy together with such known Finally, echocardiography may provide the valuable predictors as increased wall motion score index (WMSI) noninvasive and radiation-free tool for the follow-up and monitoring of coronary intervention results.42 and mitral regurgitation.33 Coronary fistulas are uncommon coronary pathology. In the context of intracoronary stem cell therapy, early injection in the infarct-related coronary bed does not seem “Pediatric” type features low-resistance connection of the

1344


Fig. 64.13: Low coronary velocity flow reserve measured in distal left anterior descending (LAD)—coronary flow velocity reserve (CFVR) = 1.7 in a hypertensive diabetic patient free of epicardial coronary disease.

Fig. 64.14: Coronary anomaly—right coronary artery (RCA) originating from the left sinus of Valsalva with interarterial course. Mild flow abnormality (turbulence) visualized in transesophageal echocardiography (TEE). (RCA: Right coronary artery; RVOT: Right ventricle outflow tract).

dilated coronary artery with cardiac chamber, which can be imaged using color Doppler, usually in the right side of the heart. TTE and TEE offer diagnosis by visualization of marked arterial dilatation and tortuosity, with multiple cross-sections of a winding vessel in select views with detectable diastolic flow pattern (Fig. 64.15). In adults, tiny fistulous connections (usually LAD—pulmonary trunk) are accidentally detected in coronary angiography and can be validated by detecting flow using color Doppler (Fig. 64.16) The echocardiographic visualization of coronary aneurysms and fistulas has been reported also in iatrogenic complications related to percutaneous coronary interventions.43

SUMMARY The evaluation of coronary arteries by modern echocardiography enables routine noninvasive detection of congenital anomalies and significant proximal stenosis, especially in LMCA, which underscore the role of this method as noninvasive and valuable screening tool in these frequently dangerous setting. Functional assessment of coronary stenosis by noninvasive CFVR contributes to physiological stratification of luminal coronary narrowing, and echocardiogram may support monitoring of coronary artery interventional treatment, offering additional prognostic information.


1345

Fig. 64.15: Pediatric type coronary fistula from the right coronary artery to the right atrium. (RV: Right ventricle; RCA: Right coronary artery; LV: Left ventricle).

Fig. 64.16: Minor left anterior descending (LAD) fistulous connection to the proximal pulmonary trunk (diastolic color flow visible) with corresponding angiogram. (Ao: Aorta; RVOT: Right ventricle outflow tract; MPA: Major pulmonary artery; LA: Left atrium; LAD: Left anterior descending; LCA: Left coronary artery).

Thus, TEE can detect coronary lesion in prognostically critical proximal locations at no added cost. Incorporation of assessment of coronary arteries in routine protocol of TEE study can be therefore recommended, and the field of diagnostic approaches based on transthoracic imaging is expanding. with evidence of clinical benefits, for example, in patients studied due to cryptogenic embolism.44

REFERENCES 1. Anjaneyulu A, Raghu K, Chandramukhi S, et al. Evaluation of left main coronary artery stenosis by transthoracic echocardiography. J Am Soc Echocardiogr. 2008;21(7):855–60. 2. Vegsundvåg J, Holte E, Wiseth R, et al. Transthoracic echocardiography for imaging of the different coronary

artery segments: a feasibility study. Cardiovasc Ultrasound. 2009;7:58. 3. Krzanowski M, Bodzon W, Brzostek T, et al. Value of transthoracic echocardiography for the detection of highgrade coronary artery stenosis: prospective evaluation in 50 consecutive patients scheduled for coronary angiography. J Am Soc Echocardiogr. 2000; 13(12):1091–99. 4. Hozumi T, Yoshida K, Akasaka T, et al. Value of acceleration flow and the prestenotic to stenotic coronary flow velocity ratio by transthoracic color Doppler echocardiography in noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty. J Am Coll Cardiol. 2000; 35(1):164–8. 5. Boshchenko AA, Vrublevsky AV, Karpov RS. Transthoracic echocardiography in the detection of chronic total coronary artery occlusion. Eur J Echocardiogr. 2009;10(1):62–8.

1346


6. Caiati C, Zedda N, Montaldo C, Montisci R, Iliceto S. Contrast-enhanced transthoracic second harmonic echo Doppler with adenosine: a noninvasive, rapid and effective method for coronary flow reserve assessment. J Am Coll Cardiol. 1999;34(1):122–30. 7. Kasprzak JD, Drozdz J, Peruga JZ, Rafalska K, et al. Definition of flow parameters in proximal nonstenotic coronary arteries using transesophageal Doppler echocardiography. Echocardiography. 2000;17(2): 141–50. 8. Kiviniemi TO, Saraste M, Koskenvuo JW, et al. Coronary artery diameter can be assessed reliably with transthoracic echocardiography. Am J Physiol Heart Circ Physiol. 2004;286(4):H1515–H1520. 9. Yao J, Taams MA , Kasprzak JD, et al. Usefulness of threedimensional transesophageal echocardiographic imaging for evaluating narrowing in the coronary arteries. Am J Cardiol. 1999;84(1):41–5. 10. Krzanowski M, Bodzon W, Dudek D, et al. Transthoracic, harmonic mode, contrast enhanced color Doppler echocardiography in detection of restenosis after percutaneous coronary interventions. Prospective evaluation verified by coronary angiography. Eur J Echocardiogr. 2004;5(1): 51–64. 11 Kasprzak JD, Drozdz J, Peruga JZ, et al. Doppler detection of proximal coronary artery stenosis using transesophageal echocardiography. Kardiol Pol. 1999;50:491–500. 12. Vrublevsky AV, Boshchenko AA, Karpov RS. Diagnostics of main coronary artery stenoses and occlusions: multiplane transoesophageal Doppler echocardiographic assessment. Eur J Echocardiogr. 2001;2(3):170–7. 13. Crowley JJ, Shapiro LM. Transthoracic echocardiographic measurement of coronary blood flow and reserve. J Am Soc Echocardiogr. 1997;10(4):337–43. 14. Caiati C, Montaldo C, Zedda N, et al. New noninvasive method for coronary flow reserve assessment: contrastenhanced transthoracic second harmonic echo Doppler. Circulation. 1999;99(6):771–8. 15. Vegsundvåg J, Holte E, Wiseth R, et al. Coronary flow velocity reserve in the three main coronary arteries assessed with transthoracic Doppler: a comparative study with quantitative coronary angiography. J Am Soc Echocardiogr. 2011;24(7):758–67. 16. Vrublevsky AV, Boshchenko AA, Karpov RS. Reduced coronary flow reserve in the coronary sinus is a predictor of hemodynamically significant stenoses of the left coronary artery territory. Eur J Echocardiogr. 2004;5(4):294–303. 17. Nishino M, Hoshida S, Egami Y, et al. Coronary flow reserve by contrast enhanced transesophageal coronary sinus Doppler measurements can evaluate diabetic microvascular dysfunction. Circ J. 2006;70(11):1415–20. 18. Holte E, Vegsundvåg J, Hegbom K, et al. Transthoracic Doppler echocardiography for detection of stenoses in the left coronary artery by use of poststenotic coronary flow profiles: a comparison with quantitative coronary angiography and coronary flow reserve. J Am Soc Echocardiogr. 2013;26(1):77–85.

19. Tani T, Tanabe K, Kureha F, et al. Transthoracic Doppler echocardiographic assessment of left anterior descending coronary artery and intramyocardial artery predicts left ventricular remodeling and wall-motion recovery after acute myocardial infarction. J Am Soc Echocardiogr. 2007; 20(7):813–19. 20. Katayama M, Yamamuro A, Ueda Y, et al. Coronary flow velocity pattern assessed noninvasively by transthoracic color Doppler echocardiography serves as a predictor of adverse cardiac events and left ventricular remodeling in patients with acute myocardial infarction. J Am Soc Echocardiogr. 2006;19(3):335–40. 21. Okayama H, Nishimura K, Saito M, et al. Significance of the distal to proximal coronary flow velocity ratio by transthoracic Doppler echocardiography for diagnosis of proximal left coronary artery stenosis. J Am Soc Echocardiogr. 2008;21(6):756–60. 22. Dimitrow PP, Galderisi M, Rigo F. The non-invasive documentation of coronary microcirculation impairment: role of transthoracic echocardiography. Cardiovasc Ultrasound. 2005;3:18. 23. Lethen H, P Tries H, Kersting S, et al. Validation of noninvasive assessment of coronary flow velocity reserve in the right coronary artery. A comparison of transthoracic echocardiographic results with intracoronary Doppler flow wire measurements. Eur Heart J. 2003;24(17):1567–75. 24. Okayama H, Sumimoto T, Hiasa G, et al. Assessment of intermediate stenosis in the left anterior descending coronary artery with contrast-enhanced transthoracic Doppler echocardiography. Coron Artery Dis. 2003;14(3): 247–54. 25. Meimoun P, Benali T, Sayah S, et al. Evaluation of left anterior descending coronary artery stenosis of intermediate severity using transthoracic coronary flow reserve and dobutamine stress echocardiography. J Am Soc Echocardiogr. 2005;18(12):1233–40. 26. Hildick-Smith DJ, Johnson PJ, Wisbey CR, et al. Coronary flow reserve is supranormal in endurance athletes: an adenosine transthoracic echocardiographic study. Heart. 2000;84(4):383–9. 27. Hoffman JI. Problems of coronary flow reserve. Ann Biomed Eng. 2000;28(8):884–96. 28. Sicari R, Nihoyannopoulos P, Evangelista A, et al. European Association of Echocardiography. Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC). Eur J Echocardiogr. 2008;9(4):415–37. 29. Hyodo E, Hirata K, Hirose M, et al. Detection of restenosis after percutaneous coronary intervention in three major coronary arteries by transthoracic Doppler echocardiography. J Am Soc Echocardiogr. 2010;23(5): 553–9. 30. Kakuta K, Dohi K, Yamada T, et al. Comparison of coronary flow velocity reserve measurement by transthoracic Doppler echocardiography with 320-row multidetector computed tomographic coronary angiography in the


31.

32.

33.

34.

35.

36.

detection of in-stent restenosis in the three major coronary arteries. Am J Cardiol. 2012;110(1):13–20. Meimoun P, Boulanger J, Luycx-Bore A, et al. Non-invasive coronary flow reserve after successful primary angioplasty for acute anterior myocardial infarction is an independent predictor of left ventricular adverse remodelling. Eur J Echocardiogr. 2010;11(8):711–18. Tona F, Caforio AL, Montisci R, et al. Coronary flow velocity pattern and coronary flow reserve by contrast-enhanced transthoracic echocardiography predict long-term outcome in heart transplantation. Circulation. 2006;114(1 Suppl): I49–I55. Rigo F, Gherardi S, Galderisi M, et al. The prognostic impact of coronary flow-reserve assessed by Doppler echocardiography in non-ischaemic dilated cardiomyopathy. Eur Heart J. 2006;27(11):1319–23. Plewka M, Krzemińska-Pakuła M, Jeżewski T, et al. Early echocardiographic assessment of coronary flow reserve after intracoronary administration of bone marrow stem cells in patients with myocardial infarction. Polski Przegląd Kardiologiczny. 2008;10:48–53. Erbs S, Linke A, Schächinger V, et al. Restoration of microvascular function in the infarct-related artery by intracoronary transplantation of bone marrow progenitor cells in patients with acute myocardial infarction: the Doppler Substudy of the Reinfusion of Enriched Progenitor Cells and Infarct Remodeling in Acute Myocardial Infarction (REPAIR-AMI) trial. Circulation. 2007;116(4):366–74. Burke AP, Farb A, Virmani R, et al. Sports-related and nonsports-related sudden cardiac death in young adults. Am Heart J. 1991;121(2 Pt 1):568–75.

1347

37. Kasprzak JD, Kratochwil D, Peruga JZ, et al. Coronary anomalies diagnosed with transesophageal echocardiography: complementary clinical value in adults. Int J Card Imaging. 1998;14(2):89–95. 38 Kozieradzka A, Prokop J, Kamiński KA, et al. Anomalous left main coronary artery originating from the right sinus of Valsalva: 2 case reports. Polski Przegląd Kardiologiczny. 2011;10:48–53. 39. Wilkins CE, Betancourt B, Mathur VS, et al. Coronary artery anomalies: a review of more than 10,000 patients from the Clayton Cardiovascular Laboratories. Tex Heart Inst J 1988;15(3):166–73. 40. Angelini P. Coronary artery anomalies: an entity in search of an identity. Circulation. 2007;115(10):1296–305. 41. Uznanska-Loch B, Plewka M, Peruga JZ, et al. Non-invasive detection of concomitant coronary artery anomaly and atherosclerotic coronary disease using transthoracic Doppler echocardiography. Arch Med Sci. 2012;8(1):162–5. 42 Wierzbowska-Drabik KA, Peruga JZ, Plewka M, et al. Nonatherosclerotic ostial stenosis of left main coronary artery: echocardiographic assessment and follow-up after surgical treatment. Echocardiography. 2006;23;133–6. 43. Lipiec P, Peruga JZ, Krzeminska-Pakula M, et al. Right coronary artery-to-right ventricle fistula complicating percutaneous transluminal angioplasty: case report and review of the literature. J Am Soc Echocardiogr. 2004; 17(3):280–3. 44. Voros S, Nanda NC, Samal AK, et al. Transesophageal echocardiography in patients with ischemic stroke accurately detects significant coronary artery stenosis and often changes management. Am Heart J. 2001;142(5): 916–22.

CHAPTER 65 Echocardiography in Hypertrophic Cardiomyopathy Dan G Halpern, Mark V Sherrid

Snapshot  Defini ons and Loca ons of Hypertrophy  Le Ventricular Ou low Tract Obstruc on  Differen al Diagnosis

INTRODUCTION Hypertrophic cardiomyopathy (HCM) is a genetic disorder with clinically unexplained myocardial hypertrophy (most commonly of the interventricular septum) that occurs in the absence of a hemodynamic cause. HCM predisposes to symptoms, dynamic left ventricle obstruction, and infrequently, to life-threatening arrhythmias.1 It is the most common inherited disorder among cardiovascular diseases (1:500) and is the leading cause of sudden cardiac death (SCD) in young adults.1 Among its previous names are idiopathic hypertrophic subaortic stenosis and muscular subaortic stenosis. The preferred nomenclature is HCM, either obstructive, or nonobstructive. HCM is inherited with autosomal dominant transmission; currently mutations in 11 genes coding for various cardiac sarcomeric proteins are associated with HCM.2,3 Varying phenotypic expressions and marked heterogeneity is a hallmark of HCM (Figs 65.1A to D). Microscopically, HCM is characterized by myocyte hypertrophy and myocytic disarray interlaced with fibrosis. Transthoracic echocardiography (TTE) is the most powerful tool for the diagnosis, management, and followup of HCM.4 TTE demonstrates the site and extent of hypertrophy, and delineates and quantifies obstruction. Before making the diagnosis, it is imperative to rule out more common secondary causes of concentric hypertrophy

 Treatment Strategies in Hypertrophic Cardiomyopathy  Surgical Septal Myectomy  Dynamic Systolic Dysfunc on

such as uncontrolled hypertension or aortic valve stenosis. As discussed below, elite young athletes may have mild degrees of hypertrophy that must be distinguished from HCM. All TTE modalities are employed: M-mode and two-dimensional (2D) imaging, spectral, continuous wave (CW), and tissue Doppler to evaluate: (a) location of hypertrophy, quantitative estimation of wall thickness; (b) detection and, if necessary, provocation of systolic anterior motion (SAM) of the mitral valve, anatomy of the mitral apparatus, and degree of mitral regurgitation (MR); (c) Doppler of left ventricular outflow tract (LVOT) velocities or mid-LV gradients at rest and after provocation; (d) evaluation of diastolic dysfunction; and (e) pulmonary arterial pressure. Echo also impacts the family of an HCM patient. Since HCM is a genetic disease, family members of diagnosed HCM patient should be screened. Annual echocardiographic surveillance should include all first degree relatives of the patient until the age of 21, and afterward every 5 years. Screening under the age of 12 years is optional unless there are suspicious symptoms of HCM or malignant family history of premature death.1 Genotype analysis for screening or confirmation of HCM is most beneficial when there is a positive family history; here, 50% have an HCM-associated mutation, whereas in sporadic cases only 30–40% have an HCM-associated gene.3

Chapter 65: Echocardiography in Hypertrophic Cardiomyopathy

A

B

C

D

1349

Figs 65.1A to D: Major patterns of hypertrophy in hypertrophic cardiomyopathy (HCM). Schematic (left panel) versus echocardiographic images (right panel). (A) Anterior septal hypertrophy; (B) Subaortic septal bulge; (C) Apical; (D) Mid–left ventricular with obstruction. Source: Reproduced in part with permission from Shah A et al. Severe symptoms in mid and apical hypertrophic cardiomyopathy. Echocardiography. 2009;26:922–33.

A

B

C

D

Figs 65.2A to D: Spectrum of sub-basal hypertrophic cardiomyopathy (HCM). (A) shows pure apical HCM; (B) shows apical HCM with some extension to the mid-LV; (C) shows apical and mid-HCM with severe encroachment of the LV cavity resulting in a small slit-like left ventricle (LV) cavity in diastole, but no LV obstruction and no apical akinetic chamber; (D) shows mid-LV HCM with mid-LV obstruction and an apical akinetic chamber. Source: Reproduced with permission from Shah A, et al. Severe symptoms in mid and apical hypertrophic cardiomyopathy. Echocardiography. 2009;26:922–33.

DEFINITIONS AND TYPES OF HYPERTROPHY Hypertrophy is defined to as end diastolic wall thickness ≥ 12 mm and HCM may be considered when wall thickness

is ≥ 15 mm in the absence of hemodynamic cause for the hypertrophy observed. There is great phenotypic variation in the location and magnitude of hypertrophy. Several common patterns of hypertrophy in HCM are depicted in Figures 65.1A to D. The most common pattern of hypertrophy is of the anterior and posterior septum, and often of the anterior wall. Other distributions are thickening restricted to the proximal portion of the septum that is referred to as discrete subaortic septal bulge; HCM that spares the base but only involves the mid and apical segments has been referred to as sub-basal HCM.5 Varieties of sub-basal HCM are shown in Figures 65.2A to D. Among these are apical HCM, mid–left ventricular thickening with severe encroachment of the LV cavity, and mid-LV obstruction with an apical akinetic chamber. Rarely, thickening is restricted to the anterior, posterior, or lateral walls.6 On occasion, the right ventricle (RV) may be thickened, and rarely obstructs the subvalvular RV outflow tract.7 The pattern of hypertrophy may be useful to predict if an individual patient will have positive testing for a HCM-related mutation. Patients with septal hypertrophy that extends all the way to the apex with a resulting crescent-shaped ventricular cavity with reversal

1350


Fig. 65.3: Systolic anterior motion (SAM) of the mitral valve. SAM of the mitral valve, drawn from an apical five-chamber view, as it proceeds in early systole. Source: Reproduced with permission from Sherrid MV, et al. An echocardiographic study of the fluid mechanics of obstruction in hypertrophic cardiomyopathy. J Am Coll Cardiol. 1993:22; 816–25.

of the normal apical concavity had a 79% probability of an HCM-associated mutation, as compared to 8% of those with a discrete subaortic septal bulge.8 The maximum wall thickness, most commonly found in the septum, is a prognosticator for SCD in HCM, as a septal thickness of <19 mm denotes a lower incidence of sudden death, whereas ≥30 mm alone indicates nearly a 2% per year risk of SCD.9 In patients with high risk for SCD the physician should discuss the benefits and risks of implantable cardioverter defibrillator implantation and consider implantation of patients at high risk.10 Maximum wall thickness is thus an important variable in HCM and should be reported in every patient. The septum is best visualized in the parasternal long-axis and short-axis views and attention should be given on the short axis to not include the RV moderator band or anomalous papillary muscles. In patients with inadequate windows due to body habitus, pulmonary disease, or atypical pattern of distribution of hypertrophy, cardiac magnetic resonance (CMR) imaging may aid in delineating wall thickness.11 It is also invaluable when the magnitude of wall thickening is ambiguous and there is doubt whether 30 mm thickening is present or not.

Left Ventricular Outflow Obstruction and Systolic Anterior Motion of the Mitral Valve While one quarter of HCM patients have LVOT obstruction at rest, two thirds of patients exhibit obstruction at rest or

after physiological provocation, including exercise.12–18 LVOT pressure gradients ≥ 30 mm Hg at rest are associated with decreased survival.17,19 Patients who are not obstructed at rest but who develop LVOT obstruction after provocation are referred to as having latent obstruction.13 LVOT dynamic obstruction causes increased LV work, decreased diastolic aortic perfusion pressure, increased supply– demand ischemia, load-related impairment in diastolic relaxation, and a midsystolic drop in instantaneous LV ejection flow velocities and volumetric flow.12,18,20,21 The most common cause of LVOT obstruction is SAM of the mitral valve with mitral–septal contact (Figs 65.3 to 65.5, Movie clips 65.1 to 65.3). The first demonstration of SAM was made with M-mode through the mitral valve by Shah et al. in 1969, revolutionizing understanding of the obstruction mechanism.22 Previously, surgical observations and cardiac catheterization suggested that LVOT obstruction was caused by a subaortic sphincter similar to that found in the right ventricular outflow tract in congenital heart disease. There are several anatomical features in HCM that permit and predispose to SAM— septal hypertrophy, anterior displacement of the mitral papillary muscles, and elongation of the mitral leaflets and chordae.12,16,23,24 These geometric–anatomical features allow ejection flow to get behind the mitral leaflets, and sweep them into the septum. Flow drag, the pushing force of flow, plays the dominant role causing SAM,12,16,25–27 while the Venturi effect, suctioning from the LVOT tunnel has a minor contribution. The septal bulge redirects ejection flow so that, in the apical 3-chamber view, it comes from a relatively posterior direction and catches the anteriorly positioned mitral leaflets (Figs 65.4 and 65.5). The anterior mitral leaflet is most often elongated.23 In most patients, both leaflets move anteriorly and participate in SAM. However, in some patients it is the posterior leaflet that extends beyond the coaptation point and obstructs.28 SAM often begins during isovolumetric systole but may begin later after the aortic valve opens.16,25 As systole progresses, pushing forces displace the mitral valve anteriorly with increase in drag as the angle of attack between the leaflet and the ejection flow increases.26 With mitral–septal contact, which may occur from early to late systole, a dynamic gradient is created across the LVOT. The pressure difference across the mitral valve pushes the valve leaflets further into the septum, further decreasing the orifice and creating higher pressure gradients.13,25 Obstruction begets more obstruction. The narrowing orifice raises the pressure difference; the rising pressure


A

1351

B

Figs 65.4A and B: The pushing force of flow. (A) The dark blue, low-velocity flow behind the mitral valve pushes the leaflets into the septum, before high-velocity flow has occurred in the outflow tract; (B) The spinnaker is pushed by the wind that strikes its undersurface. Image of Stanley Rosenfeld reproduced with permission, The Rosenfeld Collection, Mystic Seaport Museum. Source: Reproduced with permission from Sherrid MV, et al. Pathophysiology and treatment of hypertrophic cardiomyopathy. Prog Cardiovasc Dis. 2006;49:123–51. (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; LVOT: Left ventricular outflow tract.

A

B

Figs 65.5A and B: Early in systole flow drag is the dominant hydrodynamic force on the mitral leaflets (A). After mitral–septal contact, the pressure difference (gradient) is the force that pushes the mitral leaflet further into the septum (B). Source: Figure modified and reproduced with permission from Sherrid MV, et al. Systolic anterior motion begins at low left ventricular outflow tract velocity in obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol. 2000;36:1344–54.

difference further narrows the orifice. The longer in systole that the mitral valve touches the septum, the higher the gradient29 (Figs 65.6 and 65.7). Obstruction may be thought of as a tug-of-war between the anteriorly displacing force of flow and posterior restraint by the chordae and papillary muscles. Pharmacological treatment with negative inotropes decrease LV ejection acceleration and thus the pushing force on the mitral valve.30 Flow drag is related to the square of the flow velocity, so even small changes in acceleration and velocity will have a large change in the pushing force. With negative inotropes and a decrease of force on the valve, the equilibrium is moved toward posterior restraint, mitral–septal contact is delayed, and pressure gradients are reduced or eliminated. Echocardiographic evaluation of SAM and LVOT obstruction includes M-mode 2D, and Doppler imaging. Because of its high temporal resolution, M-mode through the mitral valve is very useful for diagnosing and timing of SAM and observing the duration of mitral–septal

1352


Fig. 65.6: Four separate cardiac cycles from a patient, displaying simultaneous echocardiographic and hemodynamic tracings during pharmacological manipulation of the pressure gradient by increasing doses of isoproterenol. Systolic anterior motion (SAM) without septal contact in the first systole is not associated with a significant pressure gradient. When SAM–septal contact first develops late in systole, it is brief and the pressure gradient is low (second systole). When SAM–septal contact develops early in systole, it is prolonged and the pressure gradient is high (fourth systole with higher dose isoproterenol). Source: Reprinted with permission from Pollick C, et al. Muscular subaortic stenosis: the quantitative relationship between systolic anterior motion and the pressure gradient. Circulation. 1984;69:43–9.

contact (see Fig. 65.6). In addition, M-mode through the aortic valve displays midsystolic closure or notching that correlates with the aortic bisferiens pulse. Partial closure of the aortic valve in midsystole occurs due to a transient fall of flow from the obstruction (Fig. 65.8). The best 2D view to assess SAM and measure LVOT gradients is the apical 3-chamber view where the Doppler beam is the most parallel to the LVOT blood flow and can be directed anteriorly and medially away from the left atrium to avoid confusion with MR (Figs 65.7 and 65.9). The LVOT jet is “narrower” (of shorter duration) than MR because it does not include isovolumetric systole and isovulumetric diastole. Color Doppler shows aliasing in the LVOT and CW Doppler shows typical late peaking velocities. The contour of the Doppler CW jet is concave to the left (“dagger-shaped”) because the LVOT orifice continues to narrow in systole. This continuing acceleration pattern is distinct from the aortic stenosis where the jet is convex to the left with decreasing acceleration, because the orifice is fixed in systole (see Fig. 65.7). Careful differentiation of the LVOT jet and the MR jet cannot be overemphasized. “Contaminated” jets are frequent, and lead to overestimation of the true gradient.

Fig. 65.7: Top: Continuous wave (CW) Doppler echocardiographic tracing through the obstructing orifice in the left ventricular outflow tract (LVOT) of a patient with a gradient of 64 mm Hg. The contour after the inflection point is concave to the left because of the progressive decrease in the size of the orifice formed as the mitral valve is pushed by the rising pressure gradient into the septum. Reproduced with permission from Sherrid MV, et al. Reflections of inflections in hypertrophic cardiomyopathy. J Am Coll Cardiol. 1993;54:212–9. Bottom: Comparison of the Doppler velocity tracings of the high-velocity jets of aortic stenosis, mitral regurgitation (MR), and obstructive hypertrophic cardiomyopathy (HCM). In aortic stenosis and MR, as velocity increases, acceleration decreases. In contrast, in obstructive HCM, as velocity increases, acceleration also increases. In obstructive HCM, the rising pressure difference forces the mitral leaflet against the septum, which decreases the orifice size and further increases the pressure difference. This amplifying feedback loop explains the concave contour seen in obstructive HCM. The orifice size changes as an inverse function of the pressure difference across the stenosis, with the pressure difference itself causing an increase in narrowing. Progressive orifice narrowing also explains why the jet peaks late in systole in obstructive HCM. Source: Reprinted with permission from Sherrid M. Mid-systolic drop in left ventricular ejection velocity in obstructive hypertrophic cardiomyopathy—the lobster claw abnormality. J Am Soc Echocardiogr. 1997;10:707–12.

It is important to determine what is the mechanism producing obstruction for accurate surgical planning. Although the SAM of the leaflets of the mitral valve is most commonly the obstructing culprit, the papillary muscles may obstruct instead (Figs 65.10A to C). In patients without resting gradients across the LVOT, provocative maneuvers should be performed in order to unmask obstruction because treatment of symptoms in HCM is heavily dependent on finding a gradient (Fig. 65.11). While there are many advanced treatments for gradient that relieve symptoms, there are very few, if any, treatments to improve symptoms in nonobstructed


Fig. 65.8: M-mode through the aortic valve depicting midsystolic closure of the aortic valve, correlating with midsystolic fall in ventricular ejection velocity and flow.

patients. Any decrease in preload, or afterload, or increase in contractility increases obstruction; thus, standing, Valsalva maneuver, the postprandial state, or imaging after exercise may reveal latent obstruction.13,31–34 Amyl nitrite and dobutamine are nonphysiological means to provoke gradient and thus must be viewed as suspect since the change in load they produce may not exist in daily life. Medications commonly used in cardiology that decrease preload such as nitrates, high-dose diuretics, or that decrease afterload such as angiotensin-converting enzyme blockers and dihydropyridine calcium channel blockers promote LVOT obstruction. These agents can be thought of as provocative of gradient.35 Different modalities of provocation should be used in order to ascertain LVOT obstruction. Standing and the straining phase of the Valsalva maneuver, both decrease venous return to the heart, reduce preload, and promote obstruction. In one third of patients, standing produces higher gradients than Valsalva.13 Inability to demonstrate obstruction by these simple maneuvers warrants exercising the patient.13-15,36–38 Exercise echocardiography may provoke SAM and obstruction, and provides functional information including exercise tolerance, blood pressure response, symptoms, and ischemia detection. Microvascular disease in HCM may provoke wall motion abnormalities that are not distinguishable from large epicardial coronary disease without coronary angiography. Dobutamine promotes obstruction but is nonspecific and should not be used to diagnose obstruction in HCM. Another useful modality is postprandial exercise testing, where the patient is imaged

1353

Fig. 65.9: Differentiating between the continuous wave (CW) left ventricular outflow tract (LVOT) jet and mitral regurgitation (MR) jet in obstructive hypertrophic cardiomyopathy (HCM). The panel on the left is the outflow jet alone showing the typical concaveto-the-left contour. The panel on the far right shows the MR jet that has a longer duration, and is continuous with the mitral inflow velocities shown above the baseline. The MR has higher velocity than the LVOT jet. The middle panel shows an overlapping LVOT/MR signal obtained with beam in an intermediate position. (Ac: Aortic closure; Ao: Aortic opening; Mc: Mitral closure). Source: Reproduced with permission from Yock PG, et al. Patterns and timing of Doppler-detected intracavitary and aortic flow in hypertrophic cardiomyopathy. J Am Coll Cardiol. 1986;8:1047–58.

around 1 hour after a moderate meal. The mesenteric vasodilatation creates a decrease in afterload.39 It is crucial to understand the pathophysiology of SAM when preparing for surgical correction of the obstruction as the operative technique should be tailored individually from patient to patient. The extent of septal hypertrophy, the position of the papillary muscles, and slack of the anterior or posterior mitral valve leaflets may significantly vary in their contribution to SAM.12,40 As mentioned above, a hypertrophied or anomalous papillary muscle inserting into the midanterior mitral valve leaflet without intervening chordae may be the reason for obstruction— inadequate depth of septal resection or failure to partially or completely resect the anomalous papillary muscle may leave the patient with persistent obstruction (Fig. 65.10).41 Conversely, dynamic LVOT obstruction has also been reported in conditions other than HCM such as acute coronary syndrome (ACS) with apical ballooning due to left anterior descending infarct, Takotsubo syndrome, postaortic valve replacement, concentric hypertrophy with hypovolemia, mitral valve apparatus abnormalities, and during positive inotropes use.42–46 Careful history taking,

1354

A


A

A

B

B

C

C

B

Figs 65.10A to C: Anomalous papillary muscle inserting in the middle of the anterior mitral valve leaflet and causing left ventricular outflow tract (LVOT) obstruction. Left panels show the obstructing papillary muscle on parasternal (A) and short-axis views (B) and the anatomical specimen. Center (A,B,C) and right panels (A,B) show inadequate resections in patients with this pathology (center C and right B). Because the septal resections have not been carried far enough down the septum, and because the papillary muscle abnormalities have not been addressed, there is still severe residual obstruction shown by the arrowheads in both cases. Source: Reproduced with permission from Klues HG, et al. Anomalous insertion of papillary muscle directly into anterior mitral leaflet in hypertrophic cardiomyopathy. Significance in producing left ventricular outflow obstruction. Circulation. 1991;84:1188–97, and Maron BJ, et al. Pitfalls in clinical recognition and a novel operative approach for hypertrophic cardiomyopathy with severe outflow obstruction due to anomalous papillary muscle. Circulation. 1998;98:2505–8.

electrocardiography, and echocardiographic assessment are required in order to rule out these pathologies where the treatment strategy is fundamentally different.

Mitral Apparatus and Regurgitation In HCM patients, the papillary muscles are anteriorly displaced in the LV and the mitral leaflets or chordae are elongated.16,23,47 This prepositioning predisposes to SAM.

MR is commonly seen during LVOT obstruction due to malcoaptation of the mitral valve leaflets. The MR jet is directed posteriorly; its severity varies and is maximal during peak SAM. The MR velocity is the highest velocity recorded by CW Doppler and its tracing is rounded and symmetrical; in contrast, the LVOT obstruction Doppler contour is late peaking and concave to the left (see Figs 65.7 and 65.9). MR velocity traces begin in isovolumetric systole and extend into the isovolemic


1355

Fig. 65.11: Patient with obstructive hypertrophic cardiomyopathy and latent obstruction. There is no left ventricle (LV) outflow gradient at rest. Gradient rises to 49 mm Hg after Valsalva, to 74 mm Hg after standing, and to 144 mm Hg after treadmill exercise. In 30% of cases, we found a higher standing than Valsalva gradient, as in this patient. Of the 56 patients (57%) with resting gradients < 30 mm Hg, standing provoked a gradient 30 mm Hg in 23 patients (41%), thus placing them in the domain of obstructive HCM. Standing gradient is recommended on the index echocardiogram in every patient with HCM or SAM. Source: Reproduced with permission from Joshi S, et al. Standing and exercise Doppler echocardiography in obstructive hypertrophic cardiomyopathy: the range of gradients with upright activity. J Am Soc Echocardiogr. 2011;24:75–82.

relaxation period and thus are “wider” than LVOT gradient velocities. The LVOT gradient is usually quantified directly from the CW jet (4V2) and this modality is most often employed.48 However, it is also possible to calculate it from the MR velocity and the patient’s systolic blood pressure (SBP) by using the modified Bernoulli equation: LVOTgradient(mm Hg) = [4(MRvelocity)2 + 10] − SBP, where the left atrial pressure is assumed to be 10 mm Hg. Operations or pharmacological therapy that relieve SAM and LVOT obstruction reliably improve or completely eliminate MR when it is due to SAM. Current surgical

techniques recognize the importance of the distortion of the mitral valve apparatus contributing to the SAM, LVOT obstruction, and secondary MR. Thus, to thoroughly eliminate SAM in selected patients, in addition to septal myectomy, further procedures are directed at the mitral valve: (a) papillary muscle release or reposition49,50 and (b) mitral anterior leaflet plication that shortens and stiffens the anterior leaflet.51–53 Thus, mitral valve replacement is uncommonly necessary for pure obstructive HCM. However, it is important to recognize that MR can be due to structural degenerative non-HCM abnormalities of the

1356


valve such as calcification or prolapse, and not to SAM. A clinical pearl is that the MR in these cases is often central or anteriorly directed. In these patients if severe MR is present, mitral valve replacement is usually necessary.

Diastolic Dysfunction Impaired relaxation is widely present in HCM as well as impaired compliance from myocardial fibrosis.54,55 Global and segmental assessment of diastolic function should be assessed by measurement of the transmitral inflow velocities, tissue Doppler velocities and pulmonary vein flow velocities, as well as left atrial size. Tissue Doppler velocities are decreased in HCM.56 However, the E/e' ratio has limited application in HCM and does not correlate well with LV filling pressures.54 The thickened septum usually has the greatest segmental diastolic dysfunction.57 The presence of a transmitral A-wave should also be noted. Its absence could denote atrial fibrillation or atrial stunning, which might be an important source of symptoms in patients with restrictive physiology. Furthermore, tissue Doppler imaging in a gene-positive HCM relative with normal wall thickness might denote latent subclinical cardiomyopathy by demonstrating reduced systolic (S') and early filling (e') velocities.58 Strain imaging may provide additional information on segmental dysfunction and latent myopathy.59 In patients with LVOT obstruction, the relief of the obstruction improves diastolic relaxation.60 Otherwise, no pharmacological therapy has been shown convincingly to directly improve diastolic function in HCM.61,62

Apical Hypertrophic Cardiomyopathy Apical HCM, first described by the Japanese, is more prevalent in the Asian population and consists of significant hypertrophy at the apex; the base of the LV is spared.5,63 This variant has a typical electrocardiogram exhibiting deep symmetrical T-wave inversion in leads V2-6 with apical hypertrophy and a “spade-shaped” LV cavity (Figs 65.2A to D). Because of the distribution of the hypertrophy, there is far less incidence of obstruction. Its prognosis is better than classic septal HCM but is still infrequently associated with arrhythmias and SCD.64 Previously, apical aneurysms were thought to accompany apical HCM; however, aneurysms are most often a product of mid-LV obstruction in which chronic trapping of blood at the apex, and high systolic and diastolic pressures there, lead to aneurysm formation via the mechanisms

of supply–demand ischemia and afterload mismatch.5 This pathology is best imaged by the administration of intravenous echo contrast; in the United States, Definity or Optison are used, whereas in India, Definity or Sonovue are used. Consequently, we administer intravenous contrast in all patients with apical or apical-mid HCM. CMR also may aid in diagnosing apical aneurysm.65

MID–LEFT VENTRICULAR HYPERTROPHIC CARDIOMYOPATHY An uncommon but clinically important form of HCM has a unique midventricular distribution of hypertrophy, and in many patients subsequent midcavity obstruction (see Figs 65.2A to D).5,66,67 Mid-LV hypertrophy may be recognized when the extent of the hypertrophy is greatest at the level of the papillary muscles. The highest midventricular gradients are usually recorded at the level of the hypertrophied papillary muscles. The triad of mid-LV hypertrophy, small LV cavity, and hypertrophic papillary muscles predispose obstruction as the LV comes into apposition with opposite wall and the papillary muscles.66 Mid-LV obstruction may occur on its own without development of an apical akinetic chamber; many investigators believe that mid-LV obstruction leads over time to apical aneurysm through the mechanisms of afterload mismatch and supply– demand ischemia, ballooning, scar formation, and thinning (see Figs 65.12 and 65.13). Contrast imaging is helpful for demonstrating the obstruction together with the secondary apical chamber.68 An invaluable clue in diagnosing midventricular HCM and an apical akinetic chamber is the detection of diastolic paradoxical jet flow (Fig. 65.13).69 The jet is paradoxical because it originates from the apex in early diastole and travels backward toward the LV chamber—normally diastolic flow travels toward the apex from the mitral valve. As with apical HCM, contrast is essential for diagnosis and should be given in every case, and CMR is also useful for the detection of the apical chamber.

Systolic Dysfunction and Hypertrophic Cardiomyopathy—Chronic Irreversible Verus Dynamic “Burnt out” HCM with severe irreversible systolic dysfunction is seen in a small minority (approximately 2%) of patients and is associated with increased morbidity


1357

Fig. 65.12: Two hypertrophic cardiomyopathy (HCM) patients with mid–left ventricle (LV) obstruction and apical akinetic chambers. In both cases, diastole is on the left and systole is on the right. The thin long arrows show the mid-LV hypertrophy. The arrowheads show the mid-LV obstruction. The thicker long arrow shows the apical akinetic chambers. In the patient below, echocardiographic contrast has been given to enhance visualization of the apical akinetic chamber. (LA: Left atrium; LV: Left ventricle). Source: Reproduced with permission from Shah A et al. Severe symptoms in mid and apical hypertrophic cardiomyopathy. Echocardiography. 2009;26:922–33.

Fig. 65.13: Paradoxical jet flow in mid–left ventricular (LV) obstruction with an apical akinetic chamber. Five-chamber color Doppler view of the LV in early to mid diastole. Jet from the apex is termed paradoxical because it courses from the apex toward the mitral valve, at the same time as transmitral filling, below, the red flow. There are multiple aliasing shells in the apical flow, indicating it is high velocity. Blood is trapped in the apex during systole due to the mid-LV obstruction, only to emerge upon relaxation of the obstructing neck in diastole. Paradoxical jet flow should be looked for in every patient with apical LV thickening, because it is an important sign of a hidden apical akinetic chamber. When such flow is detected, the routine administration of echocardiographic contrast will readily show the apical akinetic chamber. (AC: Apical chamber; LA: Left atrium; LV: Left ventricle. Source: Reproduced with permission from Shah A, et al. Severe symptoms in mid and apical hypertrophic cardiomyopathy. Echocardiography. 2009;26:922–33.

1358


A

B

Figs 65.14A and B: (A) The Lobster Claw Abnormality is the midsystolic drop in left ventricle (LV) ejection velocities, here seen with pulsed Doppler echocardiography at the entrance to the left ventricular outflow tract (LVOT). The midsystolic drop is due to the sudden imposition of afterload from mitral–septal contact. It is the cause of the midsystolic closure of the aortic valve and the “spike and dome” pattern seen on aortic pressure tracings in patients with hypertrophic cardiomyopathy (HCM) and LVOT gradients > 60 mm Hg. It is direct evidence of the corrosive effect of gradient in obstructive HCM; (B) The same patient after disopyramide and abolition of the gradient. Note that the midsystolic drop in ejection velocities is no longer present. Note also the decrease in initial LV ejection acceleration, which is the mechanism of benefit of disopyramide. A decrease in ejection acceleration decreases the pushing force on the mitral valve leaflets.

and premature death.70 Its pathophysiology is related to the progression of ventricular fibrosis, and it may occur in both obstructed and nonobstructed patients. The extent of myocardial fibrosis is best visualized by CMR gadoliniumdelayed hyperenhancement. More common than fixed LV systolic dysfunction, LVOT obstruction may result in dynamic systolic dysfunction due to afterload-mismatch and supply– demand ischemia.71-73 During midsystole when the flow velocity and gradient is maximal through the LVOT, there is a transient fall in LV ejection flow with partial closure of the aortic valve.73 M-mode through the aortic valve shows the classic midsystolic closure of the aortic valve while pulsed Doppler interrogation at the entrance of the LVOT shows a midsystolic drop in velocities in the shape of a “lobster claw” (Figs 65.14 to 65.17).73-75 The midsystolic drop in Doppler LV ejection velocities occurs due to a premature termination of LV contraction caused by the sudden imposition of afterload due to the obstruction.71,72 Obstruction worsens myocardial function in midsystole on top of the inherently myopathic process. As mentioned earlier, the “lobster claw” abnormality is also seen in midLV obstruction. Doppler tracing at the neck of the apical akinetic chamber, near the beginning of the mid-LV narrowing universally shows the lobster claw abnormality

during midsystole due to premature termination of contraction at the apex with flow re-established in late systole. In contrast to the irreversible type systolic dysfunction, alleviation of the LVOT obstruction improves systolic function in patients with dynamic obstruction.76,77 This is best illustrated in reported cases with sudden catastrophic LV ballooning with severe LV systolic dysfunction following the sudden transition from latent to overt high-resting gradient LVOT obstruction. Patients present with obstructive cardiogenic shock that mimics ACS. The coronary angiogram shows no significant stenoses. As treatment strategies are completely different, echocardiographic imaging is crucial to show that the obstruction is the cause of the LV dysfunction. Treatments focus on reversing precipitating causes, intravenous fluids, intravenous beta-blockers, and in resistant cases emergency surgical relief of LVOT obstruction; in contrast, ACS requires coronary reperfusion.77 Positive inotropes such as dobutamine or dopamine augment obstruction in HCM and are disastrous. Such cases require expert echocardiography continuously. Repeat echocardiograms the day after relief of obstruction either by negative inotropic therapy or surgery shows improvement in systolic function.


1359

DIFFERENTIAL DIAGNOSIS

A

A

B

C

B

D

Figs 65.15A to D: The midsystolic drop in left ventricle (LV) ejection velocities. Left panel: Doppler echocardiographic tracings in a patient with systolic anterior motion (SAM) of the mitral valve, mitral–septal contact, and a left ventricular outflow (LVOT) gradient of > 100 mm Hg. (A) Pulsed wave (PW) tracing with the cursor at the entrance of the LVOT, upstream from the mitral valve. The midsystolic drop in left ventricular ejection velocities begins at the inflection point (arrows). It is caused by afterload-mismatch. The LV is unable to maintain instantaneous ejection against the sudden rise in afterload; (B) CW tracing through both the orifice and also through the entrance of the LVOT that is apical of the mitral valve. After the inflection point (white arrow), the contour of the jet velocity becomes concave to the left. The superimposed midsystolic drop that occurs at the entrance of the LVOT is shown with the yellow arrow. The midsystolic drop also begins at the same point (white arrow). Right panel: four tracings from a patient with LVOT systolic gradient of 120 mm Hg due to SAM and mitral–septal contact. Tracings were obtained during the same examination. (A) M-mode echocardiogram shows midsystolic closure of the aortic valve leaflets. The arrow points to midsystolic closure; (B) The midsystolic drop in left ventricular ejection velocities are shown on pulsed Doppler tracing obtained from the apex. The pulsed cursor is in the body of the LV, at the entrance of the left ventricular outflow tract (LVOT). Velocity drops from 0.8 to 0.5 m/s. The arrow indicates the nadir of the midsystolic drop; (C) Tissue Doppler echocardiogram of the interventricular septum as measured from the apex of the LV. Premature termination of systolic septal shortening is shown (arrow). Scale in cm/s; (D) Continuous wave LVOT jet velocities are shown from the left ventricular apex. LVOT gradient is 120 mm Hg. Scale in m/s. Symmetry of events in early and midsystole is shown. The midsystolic closure of aortic valve correlates with the midsystolic drop in the left ventricular ejection velocities at the entrance of the outflow tract, with premature termination of the septal shortening, and with the peak of the gradient, afterload. Source: Reproduced with permission from Sherrid M, et al. Reflections of inflections in hypertrophic cardiomyopathy. J Am Coll Cardiol. 2009;54:212–19.

Other etiologies that predispose to ventricular hypertrophy may be mistakenly diagnosed as HCM. This has been termed pseudo-HCM. The most common etiology of hypertrophy is chronic hypertension but others include discrete subaortic membrane, athlete’s heart, LV noncompaction, amyloidosis, Anderson–Fabry disease, and Friedreich’s ataxia. Congenital subaortic membrane may cause high gradients in the LVOT without the dynamic obstructive pattern—the Doppler spectra is similar to aortic stenosis with midsystolic peak gradient and it is convex to the left. In symptomatic patients, it is treated by surgical resection of the membrane and replacement of the aortic valve if there is more than mild aortic insufficiency. LV noncompaction may superficially appear to be hypertrophied myocardium. But left heart contrast echocardiography or CMR differentiates the compacted myocardium from the noncompacted, trabeculated myocardium.68 Thickened myocardium is the hallmark of cardiac amyloidosis. The myocardium may have a “ground glass appearance”, but this finding is not specific and can be seen in renal failure and HCM. Moreover, with harmonic imaging it is less prominent. A most valuable clue in making the diagnosis of amyloidosis is the demonstration of low voltage on the electrocardiogram, which is the reverse of any other type of hypertrophy. Biopsy either from abdominal fat, gastrointestinal tract, or the right ventricle makes this diagnosis. The recent advent of transthyretin genetic analysis is also useful in the rare patient with mutant transthyretin. Anderson–Fabry disease, alpha-galactosidase A deficiency, a rare X-linked recessive lysosomal storage disease may present with hypertrophy and infrequently with SAM.78 It can be diagnosed with galactosidase levels in men, and better by genetic testing in both genders. Treatment with intravenous enzyme replacement is now available. Lastly, Friedreich’s ataxia is an autosomal recessive spinocerebellar neuromyelopathy that may rarely present with severe hypertrophy in childhood, but more commonly presents as a dilated cardiomyopathy.

The Athlete’s Heart Highly trained athletes may develop a physiological hypertrophic adaptation by proportionally increasing the heart size and wall thickness resembling HCM.79 The condition is not found with amateurs but rather with

1360


A

B

Figs 65.16A and B: Midsystolic drop in ejection velocities in mid–left ventricle (LV) obstruction. (A) Pulsed wave (PW) spectral Doppler with cursor located in the apical akinetic chamber at the neck of the mid–left ventricular obstruction showing prominent midsystolic drop in ejection velocity (thin arrow). There is an initial rise in velocities during the unobstructed phase (thick arrow), followed by the marked decrease in midsystolic velocities and a second peak in early diastole. The drop in velocities corresponds to the attenuation of the flow signal of the systolic jet in the obstructing neck during mid- and late systole; (B) Marked midsystolic drop in LV ejection velocities in a patient with severe mid-LV obstruction. The pulsed Doppler is in the apical chamber at the entrance of the neck of the mid-LV obstruction. Note the complete cessation of forward flow in this patient in midsystole and the robust emptying of the chamber in late systole and early diastole. The midsystolic drop in ejection velocities is due to afterload mismatch and provides persuasive evidence that the apical akinetic chamber is due to obstruction and supply–demand ischemia. Source: Reproduced with permission from Sherrid M, et al. Reflections of inflections in hypertrophic cardiomyopathy. J Am Coll Cardiol. 2009;54:212–9.

Fig. 65.17: Midsystolic drop in tissue Doppler velocities in obstructive hypertrophic cardiomyopathy (HCM). The electrocardiogram, invasively measured left ventricular outflow tract (LVOT) pressure gradient, and the tissue Doppler imaging (TDI) velocity trace from the basal septum. In the post PVC beat, note the simultaneous development of the LVOT gradient (red arrow) and the midsystolic septal deceleration notch (black arrow). Source: Reproduced with permission from Breithardt OA, et al. Mid systolic septal deceleration in hypertrophic cardiomyopathy: clinical value and insights into the pathophysiology of outflow tract obstruction by tissue Doppler echocardiography. Heart. 2005;91:379–80.

elite or professionals who train for more than 5 days a week with hours of work-out a day. The physiological adaptation of the heart to intense training depends on the type of training. Repetitive pressure load training such as weight lifting produces increased afterload with subsequent concentric hypertrophy, whereas endurance training such as jogging or cycling combines pressure and volume load, an increase that leads to a balanced increase in ventricular mass and chamber dilatation. Interestingly, the largest extent of hypertrophy has been reported in US football players, upper limit 16 mm (Fig. 65.18).80 The “gray zone” between athlete’s heart and HCM occurs in patients with wall-thickening between 13 and 16 mm.81 Other echocardiographic parameters that can be applied in gray zone patients for differentiation favoring athlete’s heart include: uniform hypertrophy pattern with an upper limit of 16 mm, LV cavity size > 55 mm, and a proportional increase in all chamber sizes with normal atria size indexed to body surface area and normal LV diastolic function. CMR may detect myocardial scarring in HCM that does not occur in athletes. In ambiguous cases, athlete’s heart may be distinguished from HCM by halting training for a period of approximately 3 months to allow regression of hypertrophy in the athlete.82


Fig. 65.18: Maximal wall thickness of professional football players. The mean value was 11.2 mm (± 0.2 mm). Six percent of players had a wall thickness > 14 mm. Source: Reproduced with permission from Abernethy et al. Echocardiographic characteristics of professional football players. J Am Coll Cardiol. 2003;41:280–4.

TREATMENT STRATEGIES IN HYPERTROPHIC CARDIOMYOPATHY Pharmacologic Therapy Pharmacologic therapy is first-line treatment for symptomatic patients with obstructive HCM and adequate drug trials should be administered before invasive measures are contemplated. In patients with obstruction, the pharmacologic treatment of HCM is based on negative inotropes to relieve the dynamic obstruction by decreasing anteriorly displacing drag forces on the mitral valve, and thus potentiating normal posterior restraint of the mitral apparatus by the papillary muscles and chordae. Beta blockade is first-line negative inotropic therapy for obstruction. Disopyramide in adequate dose is added to patients who do not respond to beta blockade.83,84 The goal of therapy in obstructed patients is improvement in symptoms and functional status and reduction in gradient. In patients without obstruction, beta blockers and verapamil are used empirically for symptoms. The end point here is improvement in functional status.

Surgical Myectomy and “Resect– Plicate–Release” Septal myectomy is indicated for HCM patients who have symptoms and gradients ≥ 50 mm Hg at rest or after

1361

physiological provocations that are refractory to medical therapy. In the modern era, more extended myectomies are performed that are explicitly designed to relieve drag forces on the mitral valve.27,53,85,86 Contemporary HCM surgical techniques also aim to both reduce septal thickness and restore more normal mitral apparatus architecture. TTE thus plays a pivotal role for planning the extent of myectomy performed and to assess the contribution of abnormal mitral anatomy to the SAM (Figs 65.19A to D). Three planes are interrogated in order to establish an effective septal resection: (a) Transverse thickness of the proximal and midseptum. Adequate myectomy redirects flow anteriorly and medially away from the mitral valve. Over-resection may result in a disastrous ventricular septal defect (VSD) while underresection results in the persistence of SAM and MR. (b) Septal long-axis plane determines the length of resection toward the apex; routinely the resection must extend 4.0 cm from the insertion of the right coronary cusp, 1.5 cm past the point of mitral septal contact, down to the level of the base of the papillary muscles. The most common cause of persistent SAM is inadequate resection in this plane, just in the subaortic area. Our surgical colleagues specifically leave the subaortic thickening because it has nothing to do with the cause of obstruction and because resection here is fraught with the above mentioned complications. (c) Medial–lateral septal plane that determines the transverse extent of the resection. While the classic Morrow myectomy was a narrow trough 1 to 1.5 cm in diameter, wider resection is now performed, particularly deeper in the ventricle. It is the subaortic medial border of this resection that is at a high risk for iatrogenic damage of the conduction system and for VSD. Additional corrective measures are added to the myectomy when abnormal mitral anatomy contributes to obstruction. Papillary muscle release is added to myectomy in selected cases that have anterior positioning of the papillary muscles in the LV cavity. Papillary release was first introduced by Messmer, Schoendube, and others and divides muscular–fibrotic tissue connections between the papillary muscles and the LV free wall.85,87 The release allows the mitral apparatus to drop posteriorly into a more normal position separating the inflow and outflow tracts of the LV. Horizontal anterior leaflet plication was first introduced by Swistel et al. It shortens and stiffens the anterior leaflet when it is elongated and billows into the outflow tract—when the anterior leaflet ≥ 30 mm (measured from mitral leaflet tip to the insertion of the

1362


A

B

C

D

Figs 65.19A to D: Surgical separation of left ventricular inflow from outflow in obstructive hypertrophic cardiomyopathy (HCM): extended myectomy and papillary muscle mobilization. (A) Line drawing of outflow relative to the mitral valve in early systole. Note the anterior position of the mitral valve coaptation. The prominent midseptal bulge redirects outflow so that it comes from a relatively posterior direction, catching the anteriorly positioned mitral valve and pushing it into the septum; (B) After subaortic septal resection. The subaortic septum has been resected, but only down to the tips of the mitral leaflets. Flow is still redirected by the remaining septal bulge so that it comes from a posterior direction. It still catches the mitral valve; SAM persists, as does obstruction; (C) The septal bulge below the mitral leaflet tips has been resected, an extended myectomy. Now, flow tracks more anteriorly and medially, away from the mitral leaflets; (D) Mobilization and partial excision of the papillary muscles is added to extended myectomy. The mitral coaptation plane is now more posterior, explicitly out of the flow stream. (See Movie Clips 65.3 and 65.4). Source: Reprinted with permission from Sherrid MV. Obstructive hypertrophic cardiomyopathy: echocardiography, pathophysiology, and the continuing evolution of surgery for obstruction. Ann Thorac Surg. 2003;75:620–32.

noncoronary aortic cusp in the 3 chamber view).52,88,89 As with reefing of a sail, the reduction of leaflet area reduces the billowing of the valve and stiffens it. Significant calcifications of the leaflet are a contraindication for the procedure. Horizontal plication is preferred over the vertical plication introduced earlier by McIntosh as the horizontal plication does not interfere with the coapting surfaces.90 At St. Luke’s-Roosevelt, NYC, the combined operation is referred to as the Resect–Plicate– Release operation (RPR) (Fig. 65.20 and Movie clips 65.3 and 65.4).52,53 Alternate successful approaches to mitral valve pathology have been developed elsewhere.50,86,91 In any given patient, preoperative planning with TTE and transesophageal echocardiogram (TEE) determines which aspects of the operation are applied. The role of TEE both before and after cardiopulmonary bypass is pivotal (Movie clips 65.3 and 65.4).27,92,93 TEE performed before decannulation allows complete assessment of the new hemodynamics and extent of septal resection. It

should assure absence of significant SAM, more than mild MR or VSD. 2D imaging should be used to measure the new septal transverse thickness and length of the plicated anterior mitral leaflet; CW and color Doppler imaging of the LVOT and septum should rule out residual obstruction or VSD, respectively. Then, the patient is given intravenous dobutamine adequate to raise the heart rate to provoke obstruction and to assess MR. If the spectral Doppler in the LVOT persistently shows a gradient more than 30 mm Hg or more than mild MR, the surgeon should initiate a second pump run for additional corrective surgery.

ALCOHOL SEPTAL ABLATION A second option for septal reduction to alleviate obstructive symptoms in HCM patients resistant to pharmacologic therapy is alcohol septal ablation.94,95 Ablation is recommended for patients who are not candidates for surgical septal myectomy. At cardiac catheterization, a catheter is introduced


1363

Dual Chamber Pacing with Short AV Delay

Fig. 65.20: Schematic representation of the hypertrophied heart in hypertrophic cardiomyopathy (HCM) depicting the morphological variations leading to obstruction and the potential surgical options for management including resection (extended myectomy), plication (horizontal mitral plication), and release (manipulation of the subvalvular structures). Also see Movie Clips 65.3 and 65.4. Source: Reproduced with permission from Swistel DG, Balaram SK. Surgical myectomy for hypertrophic cardiomyopathy in the 21st century, the evolution of the “RPR” repair: resection, plication, and release. Prog Cardiovasc Dis. 2012:498–502.

into the first septal branch of the left anterior descending coronary artery. Then, careful assessment of the perforator distribution is accomplished by injecting radiographic contrast dye or dilute echocardiographic contrast into the septal branch before the alcohol. The ablation procedure creates a locally controlled myocardial infarction in the septal region (Figs 65.21A to H). Variability in vessel anatomy exists, so the operator must be careful not to induce infarction of the distal septum, RV, anterior, lateral or apical walls, or papillary muscles.94,96 If the pre-alcohol contrast extends to any of these unexpected locales, another septal perforator must be interrogated before alcohol is injected. Once the operator is convinced that the contrast distribution is limited to the proximal septum, alcohol 100% is injected beyond an inflated balloon. As with surgery, the echocardiogram at the end of the procedure should evaluate the extent of the infarcted area, presence of SAM, MR, and VSD.

Here by shortening the atrioventricular (AV) delay complete capture of the ventricles is accomplished. Depending on the native PR interval, AV delays of 60–100 milliseconds may be required (longer for patients with intrinsic AV delay). It is uncertain how ventricular pacing improves obstruction, but it is most likely related to the ventricular dyssynchrony that is produced by ventricular pacing. Dual chamber (DDD) pacing with short AV delay is only effective in half of patients and it is not considered a primary therapy for LVOT obstruction. However, guidelines support its use in patients who are elderly or frail, or in patients who have devices for other indications like implantable cardioverter defibrillator for SCD prevention or for symptomatic bradycardia.1 Formal AV optimization with echocardiography is required for all patients who have DDD pacing for obstructive HCM.97,98 The AV delay is gradually reduced by 20 milliseconds intervals until the QRS is maximally widened (complete capture). At this point, duration of the diastolic transmitral A-wave is measured, as well as its Doppler time velocity integral (TVI), and the TVI of the whole transmitral diastolic flow tracing. This is compared to baseline measurements before ventricular capture to assure that there is no significant (<10%) decrement in A-duration and TVI. Lastly, the LVOT gradient pre and post ventricular pacing are compared to assess gradient decrease. It can sometimes take months for the full effect of DDD pacing to take effect. Disopyramide and DDD pacing have a synergistic effect on LVOT gradient.99 At least yearly echocardiography is mandatory whenever DDD pacing is used, to avoid over therapy and marked reduction of LV systolic function due to chronic dyssynchrony.

ENDOCARDITIS PROPHYLAXIS Endocarditis antibiotic prophylaxis is no longer recommended for obstructive HCM. This is a relatively rare complication of HCM with a prevalence of <1% that mainly affects patients with resting obstruction.100 The mitral valve apparatus and site of septal contact are most common locations of vegetations. TEE is the modality of choice to diagnose endocarditis and distinguish between vegetations and redundant leaflets from HCM.

1364


A

B

C

D

E

F

G

H

Figs 65.21A to H: Variety of left and right ventricular structures at risk for alcohol-induced necrosis as detected by intraprocedural echocardiography. Opacification of the medial papillary muscle of the left ventricle (LV; A, arrow), the basal segment of the posterolateral wall (B), the entire posterolateral wall in the apical four-chamber view (C, arrows), the entire interventricular septum (D), a papillary muscle (arrow) of the right ventricle (RV) via a moderator band in association with a small contrast depot within the interventricular septum (E), a small segment of the basal inferior portion (arrows) of LV free wall (parasternal short-axis view) (F), the entire posterolateral wall (G) in the apical long-axis view (same patient as C; arrows), and a larger septal portion together with a right ventricular papillary muscle (H, arrow). (LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Faber L, et al. Targeting percutaneous transluminal septal ablation for hypertrophic obstructive cardiomyopathy by intraprocedural echocardiographic monitoring. J Am Soc Echocardiogr. 2000;13:1074–9.

REFERENCES 1. Gersh BJ, Maron BJ, Bonow RO, et al.; American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic Cardiomyopathy: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Developed in collaboration with the American Association for Thoracic Surgery, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2011;58(25):e212–60. 2. Bos JM, Towbin JA, Ackerman MJ. Diagnostic, prognostic, and therapeutic implications of genetic testing for hypertrophic cardiomyopathy. J Am Coll Cardiol. 2009; 54(3):201–11.

3. Konno T, Chang S, Seidman JG, Seidman CE. Genetics of hypertrophic cardiomyopathy. Curr Opin Cardiol. 2010; 25(3):205–9. 4. Nagueh SF, Bierig SM, Budoff MJ, et al.; American Society of Echocardiography; American Society of Nuclear Cardiology; Society for Cardiovascular Magnetic Resonance; Society of Cardiovascular Computed Tomography. American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: Endorsed by the American Society of Nuclear Cardiology, Society for Cardiovascular Magnetic Resonance, and Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2011; 24(5):473–98. 5. Shah A, Duncan K, Winson G, et al. Severe symptoms in mid and apical hypertrophic cardiomyopathy. Echocardiography. 2009;26(8):922–33. 6. Maron BJ, Sherrid MV, Haas TS, et al. Novel hypertrophic cardiomyopathy phenotype: segmental hypertrophy isolated to the posterobasal left ventricular free wall. Am J Cardiol. 2010;106(5):750–2.


7. Maron MS, Hauser TH, Dubrow E, et al. Right ventricular involvement in hypertrophic cardiomyopathy. Am J Cardiol. 2007;100(8):1293–8. 8. Binder J, Ommen SR, Gersh BJ, et al. Echocardiographyguided genetic testing in hypertrophic cardiomyopathy: septal morphological features predict the presence of myofilament mutations. Mayo Clin Proc. 2006;81(4): 459–67. 9. Spirito P, Bellone P, Harris KM, et al. Magnitude of left ventricular hypertrophy and risk of sudden death in hypertrophic cardiomyopathy. N Engl J Med. 2000; 342(24):1778–85. 10. Maron BJ, Spirito P, Shen WK, et al. Implantable cardioverterdefibrillators and prevention of sudden cardiac death in hypertrophic cardiomyopathy. JAMA. 2007;298(4):405–12. 11. Rickers C, Wilke NM, Jerosch-Herold M, et al. Utility of cardiac magnetic resonance imaging in the diagnosis of hypertrophic cardiomyopathy. Circulation. 2005; 112(6): 855–61. 12. Sherrid MV. Pathophysiology and treatment of hypertrophic cardiomyopathy. Prog Cardiovasc Dis. 2006;49(2):123–51. 13. Joshi S, Patel UK, Yao SS, et al. Standing and exercise Doppler echocardiography in obstructive hypertrophic cardiomyopathy: the range of gradients with upright activity. J Am Soc Echocardiogr. 2011;24(1):75–82. 14. Maron MS, Olivotto I, Zenovich AG, et al. Hypertrophic cardiomyopathy is predominantly a disease of left ventricular outflow tract obstruction. Circulation. 2006; 114(21):2232–9. 15. Shah JS, Esteban MT, Thaman R, et al. Prevalence of exercise-induced left ventricular outflow tract obstruction in symptomatic patients with non-obstructive hypertrophic cardiomyopathy. Heart. 2008;94(10):1288–94. 16. Jiang L, Levine RA, King ME, et al. An integrated mechanism for systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy based on echocardiographic observations. Am Heart J. 1987;113(3):633–44. 17. Maron MS, Olivotto I, Betocchi S, et al. Effect of left ventricular outflow tract obstruction on clinical outcome in hypertrophic cardiomyopathy. N Engl J Med. 2003;348(4):295–303. 18. Sherrid MV, Wever-Pinzon O, Shah A, et al. Reflections of inflections in hypertrophic cardiomyopathy. J Am Coll Cardiol. 2009;54(3):212–19. 19. Elliott PM, Gimeno JR, Tomé MT, et al. Left ventricular outflow tract obstruction and sudden death risk in patients with hypertrophic cardiomyopathy. Eur Heart J. 2006;27(16):1933–41. 20. Cannon RO 3rd, Schenke WH, Maron BJ, et al. Differences in coronary flow and myocardial metabolism at rest and during pacing between patients with obstructive and patients with nonobstructive hypertrophic cardiomyopathy. J Am Coll Cardiol. 1987;10(1):53–62. 21. Cannon RO 3rd, McIntosh CL, Schenke WH, et al. Effect of surgical reduction of left ventricular outflow obstruction on hemodynamics, coronary flow, and myocardial

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

1365

metabolism in hypertrophic cardiomyopathy. Circulation. 1989;79(4):766–75. Shah PM, Gramiak R, Kramer DH. Ultrasound localization of left ventricular outflow obstruction in hypertrophic obstructive cardiomyopathy. Circulation. 1969;40(1):3–11. Klues HG, Maron BJ, Dollar AL, et al. Diversity of structural mitral valve alterations in hypertrophic cardiomyopathy. Circulation. 1992;85(5):1651–60. Klues HG, Proschan MA, Dollar AL, et al. Echocardiographic assessment of mitral valve size in obstructive hypertrophic cardiomyopathy. Anatomic validation from mitral valve specimen. Circulation. 1993;88(2):548–55. Sherrid MV, Chu CK, Delia E, et al. An echocardiographic study of the fluid mechanics of obstruction in hypertrophic cardiomyopathy. J Am Coll Cardiol. 1993;22(3):816–25. Sherrid MV, Gunsburg DZ, Moldenhauer S, et al. Systolic anterior motion begins at low left ventricular outflow tract velocity in obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol. 2000;36(4):1344–54. Sherrid MV, Chaudhry FA, Swistel DG. Obstructive hypertrophic cardiomyopathy: echocardiography, pathophysiology, and the continuing evolution of surgery for obstruction. Ann Thorac Surg. 2003;75(2):620–32. Maron BJ, Harding AM, Spirito P, et al. Systolic anterior motion of the posterior mitral leaflet: a previously unrecognized cause of dynamic subaortic obstruction in patients with hypertrophic cardiomyopathy. Circulation. 1983;68(2):282–93. Pollick C, Rakowski H, Wigle ED. Muscular subaortic stenosis: the quantitative relationship between systolic anterior motion and the pressure gradient. Circulation. 1984;69(1):43–9. Sherrid MV, Pearle G, Gunsburg DZ. Mechanism of benefit of negative inotropes in obstructive hypertrophic cardiomyopathy. Circulation. 1998;97(1):41–7. Gilligan DM, Chan WL, Stewart R, et al. Cardiac responses assessed by echocardiography to changes in preload in hypertrophic cardiomyopathy. Am J Cardiol. 1994;73(4):312–15. Gilligan DM, Marsonis A, Joshi J, et al. Cardiovascular and hormonal responses to a meal in hypertrophic cardiomyopathy: a comparison of patients with and without postprandial exacerbation of symptoms. Clin Cardiol. 1996;19(2):129–35. Cotrim CA, Adame PR, Pereira HH. Exercise echocardiography in hypertrophic cardiomyopathy-upright evaluation needed. Am J Cardiol. 2011;107(7):1101–2; author reply 1102. Maron BJ, Gottdiener JS, Roberts WC, Henry WL, Savage DD, Epstein SE. Left ventricular outflow tract obstruction due to systolic anterior motion of the anterior mitral leaflet in patients with concentric left ventricular hypertrophy. Circulation. 1978;57(3):527–33. Argulian E, Messerli FH, Aziz EF, et al. Antihypertensive therapy in hypertrophic cardiomyopathy. Am J Cardiol. 2013;111(7):1040–5.

1366


36. Drinko JK, Nash PJ, Lever HM, et al. Safety of stress testing in patients with hypertrophic cardiomyopathy. Am J Cardiol. 2004;93(11):1443–4, A12. 37. Marwick TH, Nakatani S, Haluska B, et al. Provocation of latent left ventricular outflow tract gradients with amyl nitrite and exercise in hypertrophic cardiomyopathy. Am J Cardiol. 1995;75(12):805–9. 38. Klues HG, Leuner C, Kuhn H. Left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy: increase in gradient after exercise. J Am Coll Cardiol. 1992;19(3):527–33. 39. Gilligan DM, Nihoyannopoulos P, Fletcher A, et al. Symptoms of hypertrophic cardiomyopathy, with special emphasis on syncope and postprandial exacerbation of symptoms. Clin Cardiol. 1996;19(5):371–8. 40. Klues HG, Roberts WC, Maron BJ. Morphological determinants of echocardiographic patterns of mitral valve systolic anterior motion in obstructive hypertrophic cardiomyopathy. Circulation. 1993;87(5):1570–9. 41. Klues HG, Roberts WC, Maron BJ. Anomalous insertion of papillary muscle directly into anterior mitral leaflet in hypertrophic cardiomyopathy. Significance in producing left ventricular outflow obstruction. Circulation. 1991; 84(3):1188–97. 42. Haley JH, Sinak LJ, Tajik AJ, et al. Dynamic left ventricular outflow tract obstruction in acute coronary syndromes: an important cause of new systolic murmur and cardiogenic shock. Mayo Clin Proc. 1999;74(9):901–6. 43. Ohba Y, Takemoto M, Nakano M, et al. Takotsubo cardiomyopathy with left ventricular outflow tract obstruction. Int J Cardiol. 2006;107(1):120–2. 44. Schwinger ME, O’Brien F, Freedberg RS, et al. Dynamic left ventricular outflow obstruction after aortic valve replacement: a Doppler echocardiographic study. J Am Soc Echocardiogr. 1990;3(3):205–8. 45. Pearson AC, Gudipati CV, Labovitz AJ. Systolic and diastolic flow abnormalities in elderly patients with hypertensive hypertrophic cardiomyopathy. J Am Coll Cardiol. 1988;12(4):989–95. 46. Come PC, Bulkley BH, Goodman ZD, et al. Hypercontractile cardiac states simulating hypertrophic cardiomyopathy. Circulation. 1977;55(6):901–8. 47. Hagège AA, Bruneval P, Levine RA, et al. The mitral valve in hypertrophic cardiomyopathy: old versus new concepts. J Cardiovasc Transl Res. 2011;4(6):757–66. 48. Sasson Z, Yock PG, Hatle LK, et al. Doppler echocardiographic determination of the pressure gradient in hypertrophic cardiomyopathy. J Am Coll Cardiol. 1988; 11(4):752–6. 49. Schoendube FA, Klues HG, Reith S, et al. Long-term clinical and echocardiographic follow-up after surgical correction of hypertrophic obstructive cardiomyopathy with extended myectomy and reconstruction of the subvalvular mitral apparatus. Circulation. 1995;92(9 Suppl):II122–7. 50. Kaple RK, Murphy RT, DiPaola LM, et al. Mitral valve abnormalities in hypertrophic cardiomyopathy:

51.

52.

53.

54.

55.

56.

57.

58.

59.

60.

61.

62.

63.

64.

echocardiographic features and surgical outcomes. Ann Thorac Surg. 2008;85(5):1527–35, 1535.e1. Swistel DG, Balaram SK. Resection, Plication, Release– the RPR procedure for obstructive hypertrophic cardiomyopathy. Anadolu Kardiyol Derg. 2006;6 Suppl 2:31–6. Balaram SK, Ross RE, Sherrid MV, et al. Role of mitral valve plication in the surgical management of hypertrophic cardiomyopathy. Ann Thorac Surg. 2012;94(6):1990–7; discussion 1997. Balaram SK, Tyrie L, Sherrid MV, et al. Resectionplication-release for hypertrophic cardiomyopathy: clinical and echocardiographic follow-up. Ann Thorac Surg. 2008;86(5):1539–44; discussion 1544. Nishimura RA, Appleton CP, Redfield MM, et al. Noninvasive Doppler echocardiographic evaluation of left ventricular filling pressures in patients with cardiomyopathies: a simultaneous Doppler echocardiographic and cardiac catheterization study. J Am Coll Cardiol. 1996;28(5): 1226–33. Maron BJ, Spirito P, Green KJ, et al. Noninvasive assessment of left ventricular diastolic function by pulsed Doppler echocardiography in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol. 1987;10(4):733–42. Rajiv C, Vinereanu D, Fraser AG. Tissue Doppler imaging for the evaluation of patients with hypertrophic cardiomyopathy. Curr Opin Cardiol. 2004;19(5):430–6. Nagueh SF, Lakkis NM, Middleton KJ, et al. Doppler estimation of left ventricular filling pressures in patients with hypertrophic cardiomyopathy. Circulation. 1999; 99(2):254–61. Nagueh SF, Bachinski LL, Meyer D, et al. Tissue Doppler imaging consistently detects myocardial abnormalities in patients with hypertrophic cardiomyopathy and provides a novel means for an early diagnosis before and independently of hypertrophy. Circulation. 2001;104(2):128–30. Yang H, Sun JP, Lever HM, et al. Use of strain imaging in detecting segmental dysfunction in patients with hypertrophic cardiomyopathy. J Am Soc Echocardiogr. 2003;16(3):233–9. Matsubara H, Nakatani S, Nagata S, et al. Salutary effect of disopyramide on left ventricular diastolic function in hypertrophic obstructive cardiomyopathy. J Am Coll Cardiol. 1995;26(3):768–75. Nishimura RA, Schwartz RS, Holmes DR Jr, et al. Failure of calcium channel blockers to improve ventricular relaxation in humans. J Am Coll Cardiol. 1993;21(1):182–8. Kass DA, Wolff MR, Ting CT, et al. Diastolic compliance of hypertrophied ventricle is not acutely altered by pharmacologic agents influencing active processes. Ann Intern Med. 1993;119(6):466–73. Yamaguchi H, Nishiyama S, Nakanishi S, et al. Electrocardiographic, echocardiographic and ventriculographic characterization of hypertrophic non-obstructive cardiomyopathy. Eur Heart J. 1983;4(Suppl F):105–19. Eriksson MJ, Sonnenberg B, Woo A, et al. Longterm outcome in patients with apical hypertrophic cardiomyopathy. J Am Coll Cardiol. 2002;39(4):638–45.


65. Maron MS, Finley JJ, Bos JM, et al. Prevalence, clinical significance, and natural history of left ventricular apical aneurysms in hypertrophic cardiomyopathy. Circulation. 2008;118(15):1541–9. 66. Minami Y, Kajimoto K, Terajima Y, et al. Clinical implications of midventricular obstruction in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol. 2011;57(23):2346–55. 67. Cecchi F, Olivotto I, Nistri S, et al. Midventricular obstruction and clinical decision-making in obstructive hypertrophic cardiomyopathy. Herz. 2006; 31(9):871–6. 68. Comella A, Magnacca M. Pseudo-left ventricle apical hypertrophy: bedside diagnosis with SonoVue contrast. Echocardiography. 2004;21(6):563–4. 69. Nakamura T, Matsubara K, Furukawa K, et al. Diastolic paradoxic jet flow in patients with hypertrophic cardiomyopathy: evidence of concealed apical asynergy with cavity obliteration. J Am Coll Cardiol. 1992;19(3): 516–24. 70. Harris KM, Spirito P, Maron MS, et al. Prevalence, clinical profile, and significance of left ventricular remodeling in the end-stage phase of hypertrophic cardiomyopathy. Circulation. 2006;114(3):216–25. 71. Barac I, Upadya S, Pilchik R, et al. Effect of obstruction on longitudinal left ventricular shortening in hypertrophic cardiomyopathy. J Am Coll Cardiol. 2007;49(11):1203–11. 72. Breithardt OA, Beer G, Stolle B, et al. Mid systolic septal deceleration in hypertrophic cardiomyopathy: clinical value and insights into the pathophysiology of outflow tract obstruction by tissue Doppler echocardiography. Heart. 2005;91(3):379–80. 73. Sherrid MV, Gunsburg DZ, Pearle G. Mid-systolic drop in left ventricular ejection velocity in obstructive hypertrophic cardiomyopathy–the lobster claw abnormality. J Am Soc Echocardiogr. 1997;10(7):707–12. 74. Conklin HM, Huang X, Davies CH, et al. Biphasic left ventricular outflow and its mechanism in hypertrophic obstructive cardiomyopathy. J Am Soc Echocardiogr. 2004;17(4):375–83. 75. Maron BJ, Gottdiener JS, Arce J, et al. Dynamic subaortic obstruction in hypertrophic cardiomyopathy: analysis by pulsed Doppler echocardiography. J Am Coll Cardiol. 1985; 6(1):1–18. 76. Kirschner E, Berger M, Goldberg E. Hypertrophic obstructive cardiomyopathy presenting with profound hypotension. Role of two-dimensional and Doppler echocardiography in diagnosis and management. Chest. 1992;101(3):711–14. 77. Sherrid MV, Balaran SK, Korzeniecki E, et al. Reversal of acute systolic dysfunction and cardiogenic shock in hypertrophic cardiomyopathy by surgical relief of obstruction. Echocardiography. 2011;28(9):E174–9. 78. Sachdev B, Takenaka T, Teraguchi H, et al. Prevalence of Anderson-Fabry disease in male patients with late onset hypertrophic cardiomyopathy. Circulation. 2002;105(12):1407–11. 79. Maron BJ, Pelliccia A. The heart of trained athletes: cardiac remodeling and the risks of sports, including sudden death. Circulation. 2006;114(15):1633–44.

1367

80. Abernethy WB, Choo JK, Hutter AM Jr. Echocardiographic characteristics of professional football players. J Am Coll Cardiol. 2003;41(2):280–4. 81. Pelliccia A, Maron BJ, Spataro A, et al. The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes. N Engl J Med. 1991;324(5):295–301. 82. Maron BJ. Distinguishing hypertrophic cardiomyopathy from athlete’s heart physiological remodelling: clinical significance, diagnostic strategies and implications for preparticipation screening. Br J Sports Med. 2009;43(9): 649–56. 83. Sherrid MV, Arabadjian M. A primer of disopyramide treatment of obstructive hypertrophic cardiomyopathy. Prog Cardiovasc Dis. 2012;54(6):483–92. 84. Sherrid MV, Barac I, McKenna WJ, et al. Multicenter study of the efficacy and safety of disopyramide in obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol. 2005; 45(8):1251–8. 85. Messmer BJ. Extended myectomy for hypertrophic obstructive cardiomyopathy. Ann Thorac Surg. 1994;58(2): 575–7. 86. Dearani JA, Ommen SR, Gersh BJ, et al. Surgery insight: Septal myectomy for obstructive hypertrophic cardiomyopathy–the Mayo Clinic experience. Nat Clin Pract Cardiovasc Med. 2007;4(9):503–12. 87. Schoendube FA, Klues HG, Reith S, et al. Surgical correction of hypertrophic obstructive cardiomyopathy with combined myectomy, mobilisation and partial excision of the papillary muscles. Eur J Cardiothorac Surg. 1994;8(11):603–8. 88. Swistel DG, Balaram SK. Surgical myectomy for hypertrophic cardiomyopathy in the 21st century, the evolution of the “RPR” repair: resection, plication, and release. Prog Cardiovasc Dis. 2012;54(6):498–502. 89. Balaram SK, Sherrid MV, Derose JJ Jr, et al. Beyond extended myectomy for hypertrophic cardiomyopathy: the resection-plication-release (RPR) repair. Ann Thorac Surg. 2005;80(1):217–23. 90. McIntosh CL, Maron BJ, Cannon RO 3rd, et al. Initial results of combined anterior mitral leaflet plication and ventricular septal myotomy-myectomy for relief of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. Circulation. 1992;86 (5 Suppl):II60–7. 91. Minakata K, Dearani JA, Nishimura RA, et al. Extended septal myectomy for hypertrophic obstructive cardiomyopathy with anomalous mitral papillary muscles or chordae. J Thorac Cardiovasc Surg. 2004;127(2):481–9. 92. Grigg LE, Wigle ED, Williams WG, et al. Transesophageal Doppler echocardiography in obstructive hypertrophic cardiomyopathy: clarification of pathophysiology and importance in intraoperative decision making. J Am Coll Cardiol. 1992;20(1):42–52. 93. Ommen SR, Park SH, Click RL, et al. Impact of intraoperative transesophageal echocardiography in the surgical management of hypertrophic cardiomyopathy. Am J Cardiol. 2002;90(9): 1022–4.

1368


94. Faber L, Ziemssen P, Seggewiss H. Targeting percutaneous transluminal septal ablation for hypertrophic obstructive cardiomyopathy by intraprocedural echocardiographic monitoring. J Am Soc Echocardiogr. 2000;13(12):1074–9. 95. Nagueh SF, Groves BM, Schwartz L, et al. Alcohol septal ablation for the treatment of hypertrophic obstructive cardiomyopathy. A multicenter North American registry. J Am Coll Cardiol. 2011;58(22):2322–8. 96. Singh M, Edwards WD, Holmes DR Jr, et al. Anatomy of the first septal perforating artery: a study with implications for ablation therapy for hypertrophic cardiomyopathy. Mayo Clin Proc. 2001;76(8):799–802. 97. Nishimura RA, Trusty JM, Hayes DL, et al. Dual-chamber pacing for hypertrophic cardiomyopathy: a randomized,

double-blind, crossover trial. J Am Coll Cardiol. 1997; 29(2):435–41. 98. Nishimura RA, Hayes DL, Ilstrup DM, et al. Effect of dual-chamber pacing on systolic and diastolic function in patients with hypertrophic cardiomyopathy. Acute Doppler echocardiographic and catheterization hemodynamic study. J Am Coll Cardiol. 1996;27(2):421–30. 99. Minami Y, Kajimoto K, Kawana M, et al. Synergistic effect of dual chamber pacing and disopyramide in obstructive hypertrophic cardiomyopathy. Int J Cardiol. 2010;141(2):195–7. 100. Spirito P, Rapezzi C, Bellone P, et al. Infective endocarditis in hypertrophic cardiomyopathy: prevalence, incidence, and indications for antibiotic prophylaxis. Circulation. 1999;99(16):2132–7.

CHAPTER 66 Echocardiographic Assessment of Nonobstructive Cardiomyopathies Rohit Gokhale, Manreet Basra, Victor Vacanti, Steven J Horn, Aylin Sungur, Robert P Gatewood Jr, Navin C Nanda

Snapshot  Cardiomyopathies  Dilated Cardiomyopathy (DCM)  Secondary Findings in Dilated Cardiomyopathy  The Role of Echocardiography in OpƟmizing Heart Failure  Echocardiography in Assessing Ventricular Remodeling

CARDIOMYOPATHIES The diagnosis of a cardiomyopathy encompasses a wide spectrum of cardiac diseases, all of which are characterized by cardiac myocyte dysfunction, and therefore a myopathy. While systolic dysfunction impairs end-organ perfusion, diastolic dysfunction disrupts the perfusion to the cardiac myocyte itself. This results in the propagation of a vicious cycle whereby systolic dysfunction can ensue. The World Health Organization (WHO) defined cardiomyopathy as a “disease of the myocardium associated with cardiac dysfunction” in 1995.1 The cardiomyopathies were classified according to anatomy and physiology into five major types. The inclusion of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and primary restrictive cardiomyopathy (RCM) in the classification for the first time broadened the definition, characterizing the breadth of its presentation: 1. Dilated cardiomyopathy (DCM) a. Idiopathic b. Familial/genetic c. Viral

 Findings in Dilated Cardiomyopathy Based on EƟology  RestricƟve Cardiomyopathy  Other InfiltraƟve Cardiomyopathies  InfecƟous and Metabolic Cardiomyopathies  Carcinoid Heart Disease

d. Immune-mediated e. Toxic/alcoholic 2. Hypertrophic cardiomyopathy (HCM) 3. RCM 4. ARVC/D 5. Unclassified cardiomyopathies—for example, left ventricle (LV) noncompaction It also included specific cardiomyopathies such as the following: • Ischemic • Valvular • Hypertensive • Inflammatory: Idiopathic, autoimmune, and infectious • Metabolic: Endocrine-related; storage diseases hemochromatosis/glycogen storage • Muscular dystrophies: Duchenne, Becker, and myotonic • Peripartum In 2006, the American Heart Association (AHA) scientific statement proposed a more contemporary definition and classification of the cardiomyopathies.2

1370


The expert consensus panel proposed the following definition: “Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually (but not invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are due to a variety of causes that frequently are genetic. Cardiomyopathies are either confined to the heart or are a part of generalized systemic disorders, often leading to cardiovascular death or progressive heart failure-related disability”. Cardiomyopathies are categorized into two groups: 1. Primary cardiomyopathies (predominantly involving the heart) a. Genetic: • Hypertrophic • ARVC/D. • Left ventricular noncompaction • PRKAG2 and Danon glycogen storage diseases • Conduction defects, mitochondrial myopathies, and ion channel disorders. b. Mixed: • Dilated • Restrictive. c. Acquired: • Myocarditis • Stress-induced (Takotsubo) • Peripartum • Tachycardia-induced • Infants of insulin-dependent diabetic mothers. 2. Secondary cardiomyopathies (accompanied by other organ system involvement) In 2008, the European Society of Cardiology’s working group on myocardial and pericardial diseases presented an update to the WHO/ISFC classification in which cardiomyopathy was defined as: “A myocardial disorder in which the heart muscle is structurally and functionally abnormal in the absence of coronary artery disease (CAD), hypertension, valvular disease, and congenital heart disease sufficient to explain the observed myocardial abnormality”.3 In summary, the definition and classification of cardiomyopathies continues to evolve with better understanding of the diverse disease states of the myocardium. It is important that the sonographer and cardiologist keep abreast of the developments in cardiomyopathies, since it will impact the acquisition and interpretation of echocardiographic studies.

DILATED CARDIOMYOPATHY (DCM) The primary features of all dilated cardiomyopathies include decreased cardiac output and left ventricular contractility with significantly enlarged left ventricular dimensions. The etiology of DCM is variable and encompasses a wide spectrum of diseases. These are as noted below: • Ischemic cardiomyopathy • Idiopathic cardiomyopathy • Familial cardiomyopathy • Noncompacted myocardium • Peripartum cardiomyopathy • Hemochromatosis • Infectious – Postviral myocarditis – HIV – Legionella – Sepsis • Toxic cardiomyopathy – Alcohol – Adriamycin – Other chemotherapy-induced Patients with DCM may initially present with symptoms of a low cardiac output state such as fatigue or effort intolerance. In more progressive states, they may also note orthopnea or paroxysmal nocturnal dyspnea and if untreated often present with acute congestive heart failure (CHF). Echocardiography is a valuable tool in the management of such patients and has a Class I indication according to the ACC/AHA guidelines for the management of CHF. Patients with a DCM have a constellation of diagnostic features that characterize this condition. Characterized by chamber enlargement, DCM initially affects the LV. Measuring the left ventricular dimension by echocardiography forms a cornerstone in the diagnosis of DCM. According to the ASE guidelines,4 the normal reference range for LV diastolic dimension for women is 3.9–5.3 cm and for men is 4.2–5.9 cm. When indexed to body surface area, the normal range would be 2.4–3.2 cm/m2 for women and 2.2–3.1 cm/m2 for men. LV dimensions in excess of 6.2 cm in women and 6.9 cm in men, suggest severely enlarged and abnormal ventricular size (Figs 66.1A to D; Movie clips 66.1 A to C).4

Assessment of Left Ventricular Contractility Visual estimation of left ventricular functional can be performed with two-dimensional (2D), three-dimensional (3D), and M-mode echocardiography. With M-mode measurements of left ventricular size and thickening, a

Chapter 66: Echocardiographic Assessment of Nonobstructive Cardiomyopathies

A

B

C

D

1371

Figs 66.1A to D: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A), parasternal short-axis (B), and apical four-chamber (C) views showing marked global left ventricle (LV) hypokinesis. Arrow points to a catheter in the right heart. The echogenic tricuspid valve (TV) annulus probably represents fatty infiltration; (D) M-mode also showing poor LV function with increased mitral E point to interventricular septum separation. (Ao: Aorta; DA: Descending thoracic aorta; IVS: Interventricular septum; LA: Left atrium; MV: Mitral valve; PW: Posterior wall; RV: Right ventricle) (Movie clips 66.1A to C).

reliable estimate of fractional shortening can be made, which in turn determines contractility and ejection fraction. Measurement of the ejection fraction by Simpson’s method using estimates of the left ventricular volume during systole and diastole provides an objective assessment of left ventricular contractility (see Chapter 41). The decrease in systolic function can be segmental or global depending on the underlying cause of the cardiomyopathy. Segmental wall motion abnormalities usually suggest an ischemic etiology, corresponding to CAD in the distribution to the affected segments. With time and progression of ischemic cardiomyopathy, a global decrease in contractility may be seen. Nonischemic

cardiomyopathies usually present with a global reduction in contractility, although regional differences may be seen. Regional wall motion abnormalities involving the septum are also seen in the presence of bundle branch blocks, postoperatively after coronary artery bypass grafting surgery and with chronic right ventricular pacing. Bundle branch blocks lead to mechanical dyssynchrony during ventricular systole, which further compromises contractility and cardiac output. The presence of a prolonged QRS duration, particularly left sided, in patients with heart failure is associated with more advanced myocardial disease, greater LV dysfunction, a poorer prognosis and a higher all-cause mortality.5 In the presence

1372


of bundle branch blocks, there is evidence to suggest that cardiac resynchronization therapy (CRT) decreases all-cause mortality, reduces heart failure hospitalizations, and improves left ventricular ejection fraction (LVEF) in NYHA functional Class I/II heart failure patients.6 Abnormal septal motion can also result from right ventricular pressure or volume overload with the onset of pulmonary hypertension and/or right ventricular failure (Figs 66.2 to 66.4; Movie clips 66.2—Part 1 and 2; 66.3A to C).

The increase in left ventricular dimensions is accompanied by a change in LV shape, with remodeling resulting in a more spherical structure. Measurement of the sphericity

index is helpful in this regard. The sphericity index of the LV is the ratio of the long-axis dimension to the minor-axis dimension (diameter) of the LV. The normal ratio is > 1.6. A sphericity index of < 1.5 implies pathological remodeling. As the ventricle enlarges and becomes more spherical, there also occurs a displacement of the papillary muscles apically and laterally. Consequently, there is a change in mitral valve leaflet coaptation as the length of the mitral apparatus is decreased, resulting in functional mitral regurgitation (FMR). Besides mitral regurgitation, dilatation of the LV often results in left atrial enlargement with subsequent pulmonary hypertension and right ventricle (RV) enlargement. Right ventricular contractility can be primarily affected by the etiology of the cardiomyopathy or can result from progression of left ventricular failure. In patients with DCM, wall thickness is variable but is typically within normal limits. The LV mass though, is uniformly increased.

A

B

C

D

SECONDARY FINDINGS IN DILATED CARDIOMYOPATHY Cardiac Dimensions

Figs 66.2A to D


E

A

1373

Figs 66.2A to E: Dilated cardiomyopathy. Live/real time threedimensional transthoracic echocardiography (3D TTE). (A to C) Systematic and sequential anteroposterior cropping of right ventricle (RV) demonstrates the moderator band (arrowhead) as well as other trabeculations and papillary muscles (arrow) in the right ventricle (RV); (D and E) Further cropping shows only a few trabeculations in the RV apex. There is no evidence of noncompaction. Also, there is no evidence of a mass or clot in the RV apex, which was suspected on the two-dimensional (2D) study. A prominent trabeculation in the RV apex very clearly delineated by 3D TTE (arrows in the Movie clip 66.2, Part 1) was most likely the culprit for the mass-like lesion suspected on the 2D echocardiogram. Both ventricles are dilated and show globally poor motion typical of dilated cardiomyopathy. Arrow in A, B, D, and E points to a false tendon in left ventricle (LV). Movie clip 66.2, Part 2 shows another patient with dilated cardiomyopathy and globally poor biventricular function. The arrowhead shows a large clot in the LV which when further cropped demonstrates a central echolucency consistent with clot lysis. A few trabeculations are also seen. (LA: Left atrium; RA: Right atrium) (Movie clips 66.2 Parts 1 and 2). Source: Reproduced with permission from Bodiwala K, et al. Live three-dimensional transthoracic echocardiographic assessment of ventricular noncompaction. Echocardiography. 2005;22: 611–20.

B

Figs 66.3A and B: Dilated cardiomyopathy. (A) The left ventricle (LV) end-diastolic dimension in the parasternal long axis has decreased in the follow-up study (right side) as compared to baseline examination (left side). Movie clips 66.3A (parasternal long-axis view), 3B (parasternal short-axis view), and 3C (apical four-chamber view) also show improved LV function 1 year after antifailure regimen. (Ao: Aorta; DA: Descending aorta; LA: Left atrium; PW: Posterior wall; RA: Right atrium; RV: Right ventricle; VS: Ventricular septum).

Chamber dimensions as assessed by echocardiography also aid prognostication in patients with DCM. Significant dilatation of the left atrium as noted when the left atrial dimension indexed to body surface area exceeds 26 mm/m2; has been shown to predict mortality and rehospitalization due to heart failure exacerbation.7 In patients above 70 years of age, increased indexed left atrial size was the single independent predictor of death from cardiac causes and the most important indicator of cardiac events.

With increasing right ventricular size and pressure/ volume overload, the inferior vena cava (IVC) is also dilated. It can be imaged in the subcostal views of the heart about 1–2 cm from its point of entry into the right atrium (RA). The diameter of the IVC and the percent decrease in the diameter during inspiration correlate with RA pressure. Evaluation of the inspiratory response with a brief sniff (the sniff test) is more reliable than normal inspiration alone. The normal IVC diameter is < 1.7 cm. There is a 50% decrease in the diameter when the right atrial (RA)

1374


A

B

Figs 66.4A and B: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A) and apical fourchamber; (B) views demonstrate LV and left atrial (LA) dilatation. (RA: Right atrium; RV: Right ventricle).

Fig. 66.5: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Subcostal view adjusted to demonstrate the long axis of the inferior vena cava (IVC) in a patient with dilated cardiomyopathy and severe pulmonary hypertension. (RA: Right atrium).

pressure is normal (0–5 mm Hg). A dilated IVC (> 1.7 cm) with normal inspiratory collapse (≥ 50%) is suggestive of a mildly elevated RA pressure (6–10 mm Hg). A dilated IVC with an inspiratory collapse < 50% suggests that the RA pressure is moderately elevated (10–15 mm Hg). Finally, a dilated IVC without any collapse suggests a markedly increased RA pressure of >15 mm Hg (Fig. 66.5).8

Evidence of Effusion Pericardial and pleural effusions are readily imaged on echocardiography and can be signs of significant

volume overload. In particular, the presence of bilateral right and left pleural effusions are often noted in poorly compensated cardiomyopathies. The presence of an isolated pericardial effusion can provide diagnostic data regarding the etiology of the cardiomyopathy, especially when the etiology is postinfectious such as with viral myocarditis. The pericardial effusion can be tapped with echocardiographic guidance to help in the diagnostic work-up. However, in the absence of infectious or metabolic causes such as uremia, a circumferential effusion may also be accompanied by anasarca. In patients with decompensated DCM, the distribution is typically circumferential. However, with postinfectious DCM, the effusion may be localized. The detection of stranding within the fluid suggests an inflammatory or a hemorrhagic etiology of the effusion. Although rare in cardiomyopathies, when large pericardial effusions occur, the concern for tamponade becomes a determining factor in the management. Evidence of tamponade physiology as noted by right ventricular collapse, abnormal inspiratory increase of blood flow velocity through the tricuspid valve and abnormal inspiratory decrease of mitral valve flow velocity, phasic variation in right ventricular outflow tract (RVOT) or left ventricular outflow tract flow, and exaggerated respiratory variation in IVC flow suggest significant hemodynamic compromise. The left ventricular function is further diminished, resulting in decreased cardiac output. These suggest the need for emergent evacuation of the effusion.


A

1375

B

Figs 66.6A and B: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Mitral valve M-mode echocardiography showing a B bump (A) predictive of significant left ventricular end-diastolic pressure (LVEDP) and an enlarged E-point septal separation (EPSS; B) in a patient with dilated cardiomyopathy due to a reduced stroke volume with poor systolic function. A normal EPSS should generally be < 1 cm.

Two-Dimensional and M-Mode Findings In the evaluation of patients with cardiomyopathy, helpful M-mode echocardiographic findings include E-point septal separation (EPSS) and the mitral M-mode evaluation showing a prominent “b”-bump. The distance (in millimeters) from the anterior septum to the maximal early opening (E-point) of the mitral valve is defined as the EPSS. The internal diameter of the LV is proportional to diastolic LV dimension and the maximal systolic excursion of the mitral valve is proportional to the mitral stroke volume. Therefore, the ratio of these two dimensions would be proportional to the ejection fraction. The normal EPSS is approximately 6 mm. It is significantly elevated in patients with advanced cardiomyopathy, often exceeding 15 mm. M-mode imaging also may reveal a b-bump at the end of the “a”-wave, which is also consistent with an elevated left ventricular end diastolic pressure (LVEDP) with advanced cardiomyopathies (Figs 66.6A and B).

Doppler Echocardiography Doppler echocardiography assists in assessing cardiac output, cardiac index, stroke volume, stroke volume index (stroke volume indexed to body surface area), ventricular diastolic function, pulmonary arterial pressures, and right atrial pressure. The product of the transaortic velocity time integral with the cross sectional area of the left ventricular

outflow tract (LVOT area) gives an estimate of the stroke volume and thus the cardiac output (stroke volume × heart rate). This is significantly reduced in patients with DCM. The use of the mitral inflow velocity as well as mitral annular excursion by tissue Doppler imaging provides valuable information for the evaluation of diastolic function. Diastolic dysfunction accompanies systolic dysfunction and is a determinant of the prognosis of patients with cardiomyopathy. The spectrum of diastolic dysfunction ranges from delayed relaxation to irreversible end-stage restrictive physiology. The diastolic function correlates with LVEDP. The progression to restrictive patterns of diastolic dysfunction is suggestive of volume overload and poorly compensated heart failure. The poor stroke volume results in elevated LV end-diastolic pressures and decreased deceleration time. The rapid deceleration time and an early to late diastolic peak velocity ratio of mitral flow > 1.0 were associated with a poorer prognosis among patients with an ejection fraction < 40% after a recent myocardial infarction (MI).9 Patients with reversible restrictive filling patterns have a more favorable long-term prognosis10 with lesser hospitalizations for heart failure. The evidence of a pseudonormal pattern of mitral inflow velocities (early—E-wave, and late—A-wave) can be seen when patients progress from mild diastolic dysfunction to more severe stages. It can be unmasked by imaging with the use of the Valsalva maneuver. During Valsalva, the flow into the left heart is reduced and therefore,

1376


ventricular remodeling and therefore, consideration of pharmacological and nonpharmacological treatment to correct it might be reasonable (Fig. 66.7). Evaluation of the tricuspid valve with Doppler echocardiography permits assessment of tricuspid regurgitation. A measurement of the flow across the tricuspid valve allows an estimate of the transvalvular pressure gradient. This in turn provides a noninvasive assessment of RV systolic and pulmonary artery pressures. The presence of pulmonary hypertension among patients with DCM is a poor prognostic factor and suggestive of poorly compensated cardiomyopathy.13 Therefore, Doppler assessment is a valuable tool in the follow-up and prognostication of patients with DCM. Fig. 66.7: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. An apical four-chamber view showing functional mitral regurgitation (FMR). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

the left atrial and ventricular diastolic pressure is reduced thus resulting in reduced E-wave velocities and thus an abnormal E/A ratio of < 1. The mitral inflow filling pattern enables assessment of diastolic filling (by determining deceleration time of E and evaluating for mitral annular early diastolic velocity E'). In addition, mitral annulus systolic velocity (S') and early diastolic velocity (E') are reduced in patients with DCM. It also provides useful indices of the volume status of patients. Studies have shown that the E/E' ratio correlates well with pulmonary capillary wedge pressure, which helps in prognosticating patients with cardiomyopathy.11 However, the LV inflow pattern is a less reliable estimate of LV diastolic function when there is moderate to severe mitral regurgitation. Doppler evaluation of mitral regurgitation is another valuable tool in the assessment of patients with DCM. As previously mentioned, with a more spherical architecture of the LV, the papillary muscles are displaced laterally. This in turn causes tenting of the mitral valve leaflets, which can worsen mitral regurgitation. Recently, a study12 suggested that the severity of FMR is an independent predictor of adverse events in patients with heart failure due to DCM. Severe FMR, defined as regurgitant volume (RV) > 30 mL or effective regurgitant orifice > 0.2 cm2 or vena contracta (VC) > 0.4 cm, was associated with a two-fold increased risk of adverse events after adjustment for LVEF and restrictive mitral filling pattern in patients with HF due to DCM. As a corollary, perhaps FMR is not simply a consequence of

Additional Findings With long-standing DCM, the mitral regurgitation and elevated left ventricular diastolic pressures result in left atrial enlargement. This in turn predispose patients to atrial fibrillation, which can result in further decrement of mechanical atrial function. With slow flow within the atrium, spontaneous echocardiographic contrast can be noted. Transesophageal echocardiography can often demonstrate spontaneous echocardiographic contrast within the left atrium indicative of poor systolic function among patients with atrial fibrillation. Sometimes, spontaneous echocardiographic contrast may be also seen in the LV. Although mural thrombi in the LV are more frequent in ischemic cardiomyopathy with significant wall motion abnormalities, they can occur in nonischemic DCM. They may be laminar, pedunculated, or mobile based on the duration of onset of systolic dysfunction (Figs 66.8 and 66.9; Movie clips 66.8A and B; 66.9—Part 1 and 2).14

THE ROLE OF ECHOCARDIOGRAPHY IN OPTIMIZING HEART FAILURE Patients with advanced conduction system disease necessitating pacemaker placement benefit from optimizing the pulmonary regurgitation (PR) interval with echocardiographic guidance. Using Doppler echocardiography to assess mitral inflow, the optimal atrioventricular delay can be identified as the interval that produces nonfused E and A velocities without truncating the duration of A velocity. This has been known to help improve cardiac output and the patient’s symptoms.15


A

1377

B

Figs 66.8A and B: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Apical four- (A) and three- (B) chamber views. Spontaneous echo contrast (arrowhead) is noted within the left ventricle (LV) cavity in B. Arrow points to a pacemaker in the right heart. (Ao: Aorta; DA: Descending aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clips 66.8A and B).

A

B

Figs 66.9A and B: Multiple thrombi in a patient with poor ventricular function. Two-dimensional transthoracic echocardiography. The movie clip on day 1 shows prominent thrombi (arrows), some of them mobile, in both atria and in the left ventricle (LV). A few show central echolucencies of varying sizes consistent with clot lysis. Repeat examination on day 2 shows the clots to be smaller and less prominent, most likely related to significant resorption. There was no clinical evidence for embolization. A and B are representative frames from the movie clip. (Ao: Aorta; LA: Left atrium; RA: Right atrium; RV: Right atrium) (Movie clips 66.9 Parts 1 and 2).

Among patients with left bundle branch block (LBBB), the degree of intraventricular dyssynchrony can be estimated by echocardiographic evaluation. Doppler imaging, strain imaging, tissue tracking, and tissue synchronization imaging are useful in quantification of this dyssynchrony. Dyssynchrony, assessed as the standard deviation of timeto-peak transverse strain, and contractile function assessed by global longitudinal strain predicted response to CRT.16 Patients with mild to moderate dyssynchrony and good contractile function derived significant improvement with CRT in the presence of LBBB compared with patients with

severe dyssynchrony or poor contractile function. This suggested that the degree of mechanical dyssynchrony and contractile function may be important determinants of benefit in CRT and that these measures may provide incremental value over traditional characteristics such as LVEF, QRS duration, and LBBB (Figs 66.10A to G; Movie clip 66.10A to G). More recently, Doppler tissue imaging (DTI) has been shown to add incremental information to the clinical exam of patients with ischemic cardiomyopathy.17 Among patients who demonstrate a high degree of heterogeneity

1378


A

B

C

D

E

F

Figs 66.10A to F


1379

Figs 66.10A to G: Biventricular pacing. Two-dimensional transthoracic echocardiography. Before removal of coronary sinus lead. Parasternal long-axis (A), short-axis (B), apical four-chamber (C), and subcostal (D) views. Left ventricle (LV) shows mild to moderate dysfunction with an estimated ejection fraction of 37%. The arrow points to a pacemaker lead in the right ventricle (RV). RV function is normal. After removal of coronary sinus lead due to symptomatic diaphragmatic stimulation. Parasternal long-axis (E), short-axis (F), and apical four-chamber (G) views show the marked deterioration of LV function with an estimated ejection fraction of 10–15%. RV function is unchanged. (Ao: Aorta; DA: Descending thoracic aorta; L: Liver; LA: Left atrium; MV: Mitral valve; RA: Right atrium) (Movie clips 66.10A to G).

G

assessed on DTI, it was noted to be an independent predictor of ischemic cardiomyopathy (ICM) and cardiac mortality in patients with advanced LV dysfunction.

ECHOCARDIOGRAPHY IN ASSESSING VENTRICULAR REMODELING Association between increased LV diameters at baseline and poor outcome after CRT implant has been described in some studies.18,19 LV diameter measurements by M-mode echocardiography allow acceptable estimation of LVEF and correlate with LV volumes, but are hindered by a wide margin of error when it comes to accurate LV size assessment, especially for enlarged ventricles.20 The addition of parameters such as sphericity index and endsystolic volume enable a more valid and reliable estimate of the extent of LV dilatation. Patients with extensive remodeling [end-systolic volume index (ESVI) > 103 mL/m2] and only one parameter of intraventricular dyssynchrony at baseline showed no significant changes in ejection fraction after CRT.21 Therefore, patients with low likelihood to improve in LV function after CRT were more likely to be those with larger LVs. Large ESVI at the time of implant was also an independent and strong predictor of poor outcome during long-term follow-up (Figs 66.11A and B and Movie clip 66.11). Furthermore, increased end-systolic volume limits improvement in LVEF after revascularization in patients with chronic ischemic cardiomyopathy, despite presence of viability.22 Therefore, it has also been proposed that

extensively remodeled ventricles might be beyond recovery with no significant benefit from CRT. Thus, echocardiographic evaluations complement clinical and elctrocardiographic parameters in determining the favorability of CRT. However, there remain a few limitations as echocardiography cannot always predict response to CRT with absolute certainty and this continues to be an area of evolving research. The rapid evolution of ventricular assist devices has given patients with end stage heart failure, another avenue of augmenting ventricular function. Echocardiography has a useful role in evaluating the valvular function among patients with left ventricular assist devices (LVADs). Patients with LVAD often have significant aortic regurgitation accompanying poor systolic excursion of the aortic valve due to the impaired cardiac output. Echocardiography can be used to assess cavity size in the optimization of LVAD settings to achieve clinical improvement (Figs 66.12 and 66.13; Movie clips 66.12 and 66.13).

FINDINGS IN DILATED CARDIOMYOPATHY BASED ON ETIOLOGY Familial It is often an unrecognized entity, with prevalence in epidemiological studies, of 20–50% among patients with idiopathic DCM.23,24 Most familial DCM is transmitted as an autosomal dominant condition, although all inheritance patterns have been identified (autosomal recessive, X-linked, and mitochondrial).

1380

A


B

Figs 66.11A and B: Cardiac resynchronization therapy (CRT). Biventricular pacing. Two-dimensional transthoracic echocardiography. Apical four-chamber view. (A) Patient with cardiomyopathy with poor left ventricle (LV) ejection fraction; (B) Marked improvement in LV function is noted following biventricular pacing. Arrowhead points to a pacing wire. (LA: Left atrium; MV: Mitral valve; RA: Right atrium; RV, right ventricle). These are representative frames from the movie clip (Movie clip 66.11).

A

B

Figs 66.12A and B: Left ventricular assist device in a patient with cardiomyopathy. Two-dimensional transthoracic echocardiography. Parasternal long-axis view. (A) Note very poor function of both ventricles. The aortic valve (arrow) does not open and remains in the closed position throughout because all the ventricular flow is routed by the left ventricle (LV) assist device into the proximal ascending aorta (Ao). There is no direct ejection of flow into the AO through the aortic valve; (B) Color Doppler examination shows significant aortic regurgitation (AR). (LA: Left atrium; RV: Right ventricle) (Movie clips 66.12A and B).

Fig. 66.13: Left ventricular assist device. Two-dimensional transthoracic echocardiography. Parasternal long-axis view. The ventricular septum is dyskinetic. Arrowhead points to an assist device in the left ventricle (LV). (Ao: Aorta; RV: Right ventricle) (Movie clip 66.13).


The diagnosis requires the typical features of a DCM, that is LV dilatation and impaired systolic function (i.e. LVEF < 40–50% or fractional shortening < 25%). Familial cardiomyopathy is diagnosed in the setting of a family history of two or more closely related family members with idiopathic dilated cardiomyopathies.

1381

Peripartum cardiomyopathy is a fairly uncommon but serious condition with an incidence of 1 in 3,000 to 4,000 live births in the United States. It is seen most commonly in the African American population, advanced age pregnancies, and high-risk pregnancies such as twins and toxemia.25 Traditionally, it is defined as a cardiomyopathy developing between the last month of pregnancy and the first 5 months postpartum, in the absence of any other determinable etiology for heart failure or any other demonstrable heart disease prior to the last month of pregnancy.26 This definition has been modified to include the echocardiographic criteria of left ventricular dysfunction with ejection fraction < 45%, or M-mode fractional shortening < 30%, or both and left ventricular end-diastolic dimension indexed to body surface area of > 2.7 cm/m2.27,28 Various etiologies postulated include viral infection, autoimmune mechanisms, hormonal changes, genetic disorders, and toxemia.26 Echocardiography has been the diagnostic procedure of choice because it involves no radiation exposure, is noninvasive, and still provides all the required information.

After the diagnosis has been established, a follow-up echocardiogram is recommended in the postpartum period at 6 weeks, 6 months, and yearly thereafter.28 It has been shown that women who did not recover ventricular function completely had higher left ventricular end-diastolic dimension and a lower fractional shortening at the time of diagnosis as compared to those women who did have complete recovery.29 Most recently, TAPSE (tricuspid annular plane systolic excursion) has been used to study RV systolic function in peripartum cardiomyopathy patients as compared to DCM patients.30 Mean TAPSE was significantly less in postpartum cardiomyopathy as compared with DCM patients, and a TAPSE ≤ 14 mm was found in the majority of postpartum cardiomyopathy patients and in about one-third of DCM patients. Therefore, the RV systolic function (measured by TAPSE) is worse in peripartum cardiomyopathy patients as compared to DCM patients. Like other dilated cardiomyopathies, peripartum cardiomyopathy may present with a thrombus inside the dilated LV cavity, which can be seen on 2D or 3D echocardiography (Figs 66.14A to R; Movie clip 66.14). Dobutamine echocardiography has been used to challenge the LV in women who have recovered from peripartum cardiomyopathy. This permits the assessment of contractile reserve, which is a measure of the enhanced contractility with the infusion of an inotropic agent over baseline values. Patients with recovered peripartum cardiomyopathy, when compared with age and parity matched controls, have a lower

A

B

Peripartum

Figs 66.14A and B

1382


C

D

E

F

G

H

Figs 66.14C to H


I

J

K

L

M

N

Figs 66.14I to N

1383

1384


O

P

Q

R

Figs 66.14A to R: Peripartum cardiomyopathy. Morphological assessment of left ventricular thrombus by live three-dimensional transthoracic echocardiography. (A) Arrowhead points to the thrombus attached to left ventricle (LV) apex; (B and C) Transverse plane (TP, horizontal plane or short axis) section at the attachment point of the thrombus (arrowhead) shows it to be highly echogenic (viewed en-face, arrow in C); (D and E) TP and longitudinal plane (LP, vertical plane or long axis) sections through the thrombus (arrowhead) showing the echogenic attachment (arrow) and a large echolucency within the thrombus consistent with lysis; (F to H) TP and both TP and LP sections at midthrombus level showing clot lysis. (I and J) TP section at thrombus tip level showing a solid rim (viewed en-face); (K and L) LP section through thrombus showing clot lysis. (M and N) Frontal plane (FP) section through the thrombus viewed en-face (M) and after tilting (N); (O) TP and LP sections through the thrombus. The data set has been tilted and rotated to show the position of the FP; (P to R) Oblique sections through the thrombus. The arrow in R points to residual fibrin strands within the lytic area of the thrombus. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clip 66.14). Source: Reproduced with permission from Sinha A, et al. Morphological assessment of left ventricular thrombus by live three-dimensional transthoracic echocardiography. Echocardiography. 2004;21:649–55.

contractile reserve.31 This might explain why patients with peripartum cardiomyopathy are at greater risk for relapse in subsequent pregnancies. This was further clarified by Fett et al. who showed that patients with a history of peripartum cardiomyopathy and recovery had a lower risk of relapse when they demonstrated adequate contractile reserve as assessed by exercise echocardiography.32 Thus, the assessment of cardiac reserve also helps to identify

those at risk of relapse, with a higher incidence of relapse in patients with lower cardiac reserve.

Left Ventricular Noncompaction (LVNC) Noncompaction of the ventricular myocardium is a cardiomyopathy thought to be caused by the arrest of normal embryogenesis of the endocardium and


Fig. 66.15: Left ventricular noncompaction. Two-dimensional transthoracic echocardiography. Contrast study using definity was performed for better assessment of left ventricle (LV) endocardial border. Arrows point to multiple trabeculations in the LV apex indicative of noncompaction. Note very poor LV function often noted in this entity. (RV: Right ventricle) (Movie clip 66.15).

myocardium. This abnormality may be associated with other congenital cardiac defects, although it is also seen in the absence of other cardiac anomalies. Clinical manifestations are highly variable, ranging from patients who remain asymptomatic to those with profound CHF, arrhythmias, and systemic thromboemboli. The prevalence of noncompaction cardiomyopathy is estimated to be at 0.05% in the general population based on echocardiographic studies.33 In normal fetal ontogenesis, the myocardium condenses and intertrabecular recesses are reduced to capillaries. Deep intertrabecular recesses communicating with the ventricular myocardium may evolve in some patients because of arrest of compaction of the loosely interwoven network of myocardial fibers during intrauterine life.34 Ventricular noncompaction affects the apical and midventricular segments of both the inferior and lateral wall in > 80% of the patients35 and generally spares the basal segments. Segmental appearance is an important feature, since a more diffuse prominent trabecular pattern may be present in hypertrophied hearts.36 It is identified by the presence of more than three prominent trabeculations in the LV found at autopsy or on various imaging techniques including echocardiography and magnetic resonance imaging (MRI).

Echocardiographic Features of LVNC There are two separate echocardiographic criteria for the diagnosis of LVNC—the Jenni criteria, which stress the

1385

presence of a two-layered structure and the Chin criteria, which focus on the depth of recesses compared to the height of the trabeculae.35,37 The Jenni criteria include: • Ratio of thick noncompacted layer to thin compacted > 2 and • Perfused intertrabecular recesses are supplied by intraventricular blood on color Doppler analysis. The Chin criterion is based on: • Ratio of distance from epicardial surface to the trough of the trabecular recesses and distance from epicardial surface to peak of trabeculation < 5. In both of these, it is important that no other cardiac structural abnormalities such as valvular obstruction or coronary anomalies are present. The parasternal shortaxis view of the apex is particularly helpful in visualizing the recesses (Figs 66.15 to 66.18 and Movie clips 66.15 and 66.17A and B). Color Doppler helps to differentiate noncompacted ventricular myocardium from prominent normal myocardial trabeculations, false tendons, aberrant bands, cardiac tumors, and left ventricular apical thrombus by demonstrating direct blood flow from ventricular cavity into deep intertrabecular recesses in noncompacted myocardium.35 The incremental value of live 3D transthoracic echocardiography (3D TTE) has been illustrated by Bodiwala et al. and Baker et al.38,39 This modality allows for more detailed and accurate diagnosis as the intracavitary echo densities suspicious for trabeculations can be tracked in multiple directions from the base to the apex. Besides viewing the entire trabeculation in detail, there is a well-demonstrated distinction between prominent noncompacted and thin compact layer of LV myocardium. The ability to quantify the depth of penetration of the intertrabecular recesses in addition to localizing the exact dimensions and severity of noncompaction provides prognostic value. Evidence of extensive left ventricular involvement is associated with a poorer prognosis and prompt referral for transplantation, or prophylactic defibrillator implantation has been suggested to be useful in this situation.40 Further, it also enables distinguishing LVNC from other differential diagnoses such as left or right ventricular hypertrophy, apical hypertrophic cardiomyopathy (HCM), right or left ventricular dysplasia, endocardial fibroelastosis, and intracardiac masses such as thrombus and tumors. Differentiation from these entities is enhanced by full characterization of segmental involvement, especially of

1386


A

B

C

D

E

Figs 66.16A to E: Left ventricular noncompaction. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A), apical three-chamber (B), apical four-chamber (C and D) views showing the trabeculations of the LV wall and deep intertrabecular recesses (arrowheads) characteristic of left ventricle (LV) noncompaction. (E) Apical two-chamber view with color Doppler showing direct blood flow from the ventricular cavity into deep intertrabecular recesses in LV noncompaction. (Ao: Aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle).


A

1387

B

Figs 66.17A and B: Left ventricular noncompaction. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A) and apical two-chamber (B) views with Doppler evidence of flow in the recesses (B). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; MR: Mitral regurgitation; MV: Mitral valve; RV: Right ventricle) (Movie clips 66.17A and B).

A

B

C

Figs 66.18A to C: Isolated left ventricular noncompaction. Two-dimensional transthoracic echocardiography. (A) Arrow points to prominent trabeculations involving the whole extent of left ventricular (LV) posterolateral wall consistent with noncompaction; (B) Myocardial perfusion study using perflutren lipid microspheres demonstrated apical hypoperfusion (arrowhead); (C) Echo contrast time–intensity curves show diminished rate of filling as well as peak filling in the LV apex as compared to the ventricular septum (VS). (LA: Left atrium; MV: Mitral valve; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Bodiwala K, et al. Live three-dimensional transthoracic echocardiographic assessment of ventricular noncompaction. Echocardiography. 2005;22:611–20.

1388


the right ventricular apex and by correct measurement of the noncompacted/compacted ratio (N/C ratio). This is best performed in cross-sectional views obtained perpendicular to the heart’s axis,38 and is superior with 3D TTE. Therefore, the full characterization of noncompaction with 3D TTE is of clinical value. In addition, 3D TTE may potentially offer a better modality for following patient response to therapy, including use of -blocking agents that have been associated with improvements in ventricular function (Figs 66.19 to 66.25; Movie clips 66.19 [parts 1 to 5], 66.20, 66.22A to C, 66.23A to C, and 66.24 [parts 1 and 2]). When conventional images are of poor quality or nondiagnostic, contrast agents can be used to enhance endocardial border delineation.41,42 The opacification within the deep recesses can help confirm the diagnosis. Contrast can also be used to determine the associated presence of thrombi with and without clot lysis.

Takotsubo Cardiomyopathy/Left Ventricle Apical Ballooning Syndrome Takotsubo cardiomyopathy, also called stress-induced cardiomyopathy or broken heart syndrome, is an increasingly reported syndrome characterized by transient systolic dysfunction of the apical and/or mid segments of the LV that occurs in the setting of acute emotional stress. The initial presentation often mimics that of an acute MI with concomitant rise in cardiac biomarkers, electrocardiographic abnormalities, and in severe cases with features of acute CHF.43 However, coronary angiography does not reveal a significant obstruction that can explain the nature or magnitude of systolic dysfunction noted. The etiology is thought to be related to the hyperadrenergic state associated with emotional stress or psychological trauma. The classical finding of apical ballooning (typical variant) and/or midventricular hypokinesis is usually seen on left ventriculography or echocardiography.43–45 In a minority of cases, the transient left ventricular hypokinesis is restricted to the midventricular segments (“atypical variant” or “apical sparing variant”) without involvement of the apex.46 As reported by Kurowski et al. the atypical variant may account for nearly 40% of patients with Takotsubo cardiomyopathy.46 More recently, Manzanal et al.47 also described a case series of patients with the atypical variant, the so-called inverted Takotsubo

cardiomyopathy, characterized by basal and midventricular segmental akinesis. At times, right ventricular dysfunction can accompany left ventricular dysfunction (Figs 66.26A and B Movie clips 66.26A and B).48 The left ventricular dysfunction is reversible with recovery of ventricular function anticipated with medical management as outlined for DCM.46

Tachycardia-Induced Cardiomyopathy and Other High-Output States Tachycardia-induced cardiomyopathy is a well-recognized entity leading to DCM, but its exact incidence is still unknown. It should be suspected in patients with atrial as well as ventricular arrhythmias including atrial fibrillation, atrial tachycardias, re-entrant arrhythmias, ventricular tachycardias, and premature ventricular contractions (PVCs) resulting in persistently high heart rates. It has all the features of DCM on echocardiography with the exception that LV end-diastolic dimension (EDD) tends to be smaller in patients with tachycardia-mediated cardiomyopathy.49 Follow-up of the ventricular function after a period of 3–6 months with satisfactory rate control will often demonstrate significant recovery of function (Fig. 66.27A and B; Movie clips 27A and B).

Ischemic Cardiomyopathy (ICM) Ischemic cardiomyopathy is a form of DCM characterized by systolic dysfunction due to CAD. The prevalence of ischemic cardiomyopathy in the United States is nearly two-thirds of all cases of chronic systolic dysfunction.50 Patients with CAD have concomitant risk factors such as hypertension, which can independently cause a decline in systolic function. The echocardiographic features are typical of DCM. An important finding is that of significant wall motion abnormalities independent of conduction system abnormalities, consistent with a territory of ischemia on prior infarction. Revascularization can result in improvement of ventricular function. However, with long-standing cardiomyopathy, evidence of increased end-systolic volume limits improvement in LVEF after revascularization in patients with chronic ischemic cardiomyopathy despite the presence of viability. Further, secondary features on echocardiography such as myocardial thinning with increased echogenicity and akinesis or dyskinesia of the left ventricular segment suggest that the systolic function


A

B

C

D

E

1389

Figs 66.19A to E: Combined left and right ventricular noncompaction. Live/real time three-dimensional transthoracic echocardiography. (A and B) Arrows point to prominent trabeculations in both ventricles; (C) Arrows show multiple prominent trabeculations in RV; (D) Transverse cropping of left ventricle (LV) apical area shows a honeycomb-like appearance (arrow) typical of noncompaction; (E) Echo contrast study using perflutren lipid microspheres shows filling of intertrabecular recesses with the contrast agent (arrows). See Movie clip 66.19, Part 1 to 5. Systemic cropping of the three-dimensional data set demonstrates extensive trabecular involvement of the LV (arrowheads). (AV: Aortic valve; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle) (Movie clips 66.19 Parts 1 to 5). Source: Reproduced with permission from Bodiwala K, et al. Live three-dimensional transthoracic echocardiographic assessment of ventricular noncompaction. Echocardiography. 2005; 22:611–20.

1390


A

B

C

D

E

F

Figs 66.20A to F


G

H

I

J

K

1391

Figs 66.20A to K: Combined left and right ventricular noncompaction. Live/real time three-dimensional transthoracic echocardiography. (A and B) Arrows point to a cauliflower-like mass in right ventricle (RV) mimicking a tumor. Magnetic resonance imaging in this patient erroneously suggested a ventricular septal tumor; (C to E) Arrows point to massive trabeculations in both left ventricle (LV) and RV consistent with noncompaction; (F and G) Transverse (F) and anteroposterior (G) cropping of LV apical area show a honeycomblike appearance (arrow) typical of noncompaction; (H) Arrowheads point to multiple trabeculations occupying over 80% of RV cavity; (I and J) Arrow points to massive trabeculations in the ventricular septal area; (K) Arrows point to multiple trabeculations crossing the RV cavity transversely. (Ao: Aorta; AV: Aortic valve; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RCA: Right coronary artery; RV: Right ventricle; TV: Tricuspid valve; # 1, anterior leaflet of tricuspid valve, # 2, septal leaflet of tricuspid valve) (Movie clip 66.20). Source: Reproduced with permission from Bodiwala K, et al. Live three-dimensional transthoracic echocardiographic assessment of ventricular noncompaction. Echocardiography. 2005;22:611–20.

1392


Fig. 66.21: Isolated right ventricular noncompaction. Live/real time three-dimensional echocardiography. In this patient, prominent trabeculations (arrowhead) occupy over 80% of the right ventricular (RV) cavity.

A

C

B

Figs 66.22A to C: Isolated right ventricular noncompaction. Twodimensional and live/real time three-dimensional transthoracic echocardiography. (A) Two-dimensional study. Arrowheads point to a few muscle bands in the right ventricular apex but there is no clear-cut evidence for noncompaction; (B) Three-dimensional study. Cropping of the image reveals a honeycomb-like appearance typical of RV noncompaction. Trabeculations (arrowhead) fill the distal 40% of RV almost completely; (C) Intracardiac echocardiography. Shows RV noncompaction (arrowhead). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clips 66.22A to C). Source: Reproduced with permission from Reddy VK, et al. Incremental value of live/real time three dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26:598–609.


1393

A

B

C

Figs 66.23A to C: Isolated left ventricular noncompaction and thrombi in an adult patient. (A) Two-dimensional transthoracic echocardiography. Arrowheads show echodensities in the LV suggestive of thrombi with areas of echolucency consistent with clot lysis. The arrow points to adjacent trabeculations which are relatively less echogenic; (B and C) Live/real time three-dimensional transthoracic echocardiography. Arrows point to multiple trabeculations in left ventricle (LV). In C, one of the echodensities (arrowhead) was cropped revealing a prominent echolucency, typical of clot lysis (Movie clips 66.23A to C). Source: Reproduced with permission from Yelamanchili P, Nanda NC, Patel V, et al. Live three-dimensional echocardiographic demonstration of left ventricular noncompaction and thrombi. Echocardiography. 2006;23:704–6.

Fig. 66.24: Isolated left ventricular noncompaction and thrombus in another patient. Live/real time three-dimensional transthoracic echocardiography. Arrowhead points to a clot in the left ventricle (LV). Clot hypermobility (arrowhead) is demonstrated in the Movie clip 66.24, Part 1. Movie clip 66.24, Part 2 is from another patient with isolated left ventricular noncompaction with thrombi in the LV cavity. The thrombi (T) are easily differentiated from trabeculations (arrowheads) by their much higher echogenicity. Thrombi are denoted by arrowheads in sections of the movie containing no trabeculations. (RV: Right ventricle) (Movie clips 66.24 Parts 1 and 2). Source: Reproduced with permission from Yelamanchili P, Nanda NC, Patel V, et al. Live three-dimensional echocardiographic demonstration of left ventricular noncompaction and thrombi. Echocardiography. 2006;23:704–6.

1394


Fig. 66.25: Left ventricular noncompaction. Shows the technique of estimating left ventricle (LV) mass in by live/real time three-dimensional transthoracic echocardiography. Source: Reproduced with permission from Rajdev S, Nanda NC, Singh A, Baysan O, Hsiung MC. Comparison of twoand three-dimensional transthoracic echocardiography in the assessment of trabeculations and trabecular mass in left ventricular non-compaction. Echocardiography. 2007;24: 760–7.

A

B Figs 66.26A and B: Takotsubo cardiomyopathy. Apical four-chamber view. Velocity vector imaging. The individual arrows point to the direction of endocardial motion, while the lengths are proportional to velocity. (A) Compared to baseline (left figure), the velocity of motion has significantly increased in the left ventricle (LV) mid segments, while the apex is still hypokinetic during follow up (right figure); (B) No change is noted by visual inspection in the left atrial (LA) wall motion during follow-up (right figure) as compared to baseline (left figure). This patient belonged to a series of five patients with Takotsubo cardiomyopathy, in whom the left atrium also appeared to be involved by velocity vector imaging with a statistical tendency toward improvement during follow-up. (RA: Right atrium; RV: Right ventricle). These are representative frames from the movie clips. (Movie clips 66.26A and B).


A

1395

B

Figs 66.27A and B: “Tachycardia-induced cardiomyopathy.” Two-dimensional transthoracic echocardiography. (A) Parasternal longaxis view. The left ventricle (LV) is dilated with poor function. The heart rate was 133/min; (B) Apical four-chamber view. The patient was placed on a -blocker, which resulted in heart rate reduction and improvement in LV function. (Ao: Aorta; DA: Descending aorta; LA: Left atrium; MV: Mitral valve; RA: Right atrium; RV: Right ventricle) (Movie clips 66.27A and B).

A

B

Figs 66.28A and B: Ischemic cardiomyopathy. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A) and apical four-chamber (B) views. All the chambers are markedly dilated with extremely poor function of both ventricles. The septum is thin and echogenic, consistent with scarring and fibrosis indicating ischemic heart disease. Arrowhead points to a pacemaker wire. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle) (Movie clips 66.28A and B).

is unlikely to benefit from revascularization (Figs. 66.28A and B; Movie clips 66.28 A and B). Therefore, it has also been proposed that extensively remodeled ventricles might be beyond recovery with no significant benefit from revascularization. Thus, echocardiographic evaluations complement clinical parameters in determining the favorability of revascularization in ischemic cardiomyopathy.

Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D) ARVC/D is a genetically predetermined disorder, often causing sudden death among young, apparently healthy

individuals. Its prevalence is estimated between 1:2,000 and 1:5,000.51 It is characterized by fibrofatty infiltration of right ventricular myocardium, which often leads to ventricular arrhythmias, RV dilation, and dysfunction, ultimately leading to RV failure.52,53 Criteria for the clinical diagnosis of ARVC/D were proposed in 1994 by the International Task Force, based on structural, histological, ECG, arrhythmic, and familial features of the disease.54 Various echocardiographic findings reported in ARVC/D patients include: 1. Abnormalities of RV morphology (trabecular derangements, hyper-reflective moderator band, focal RV aneurysms, and sacculations);55

1396


an abnormal trabecular pattern, a highly reflective and irregularly shaped moderator band, or an isolated dilation of the RVOT.55 The use of Doppler tissue imaging and 2D strainderived parameters to assess regional contractility to identify ARVC/D has been reported,59 but this is not yet a standard criterion. In addition, there is an increased use of 3D echocardiographic measurements of RV volume and ejection fraction, which have been shown to correlate with MRI values and hence can be used in prognostication as well as in follow-up of patients (Fig. 66.29; Movie clip 66.29).60,61

Toxic Cardiomyopathies Fig. 66.29: Arrhythmogenic right ventricular dysplasia. Twodimensional transthoracic echocardiography. Apical four-chamber view shows diminished right ventricular (RV) function as well as presence of small, localized berry-like aneurysms involving the free wall (arrows) typical of this entity. The left ventricle (LV) function is normal. (LA: Left atrium; MV: Mitral valve; RA: Right atrium) (Movie clip 66.29A).

2. Abnormal RV structure (increased end-diastolic and end-systolic RV inflow tract dimensions and RVOT dimension in long- and short-axis views);56 and 3. Abnormal RV function (global hypokinesis or regional wall motion abnormalities).57 It has been reported that RVOT > 30 mm is the most common abnormality associated with Task Force Criteria diagnosis of ARVC/D, followed by RV dysfunction.57 Over the past years, advancement in technology and imaging including cardiac MRI, 3D echo, and contrast echo have led to the addition of more quantitative imaging parameters to improve diagnostic sensitivity while maintaining the diagnostic specificity.58 These include: Major criterion: 1. Regional RV akinesia/dyskinesia/aneurysm 2. Parasternal long-axis RVOT (end-diastole) > 32 mm or parasternal short-axis RVOT > 36 mm or fractional area change < 33% Minor criterion: 1. Regional akinesia/dyskinesia 2. Parasternal long-axis RVOT > 29 to < 32 mm or parasternal short-axis RVOT > 32 to < 36 mm or fractional area change > 33% to < 40% Echocardiographic findings reported in asymptomatic individuals, who were family members of patients with ARVC/D included—inferobasal localized diastolic bulge,

Chemotherapy-Induced Cardiomyopathy Chemotherapy with adriamycin or other anthracyclines is often adopted for a variety of hematological malignancies. It, however, is associated with cardiotoxicity and can be an issue among adult patients receiving chemotherapy as well as survivors of childhood cancers.62 The toxicity is likely due to a combination of factors including reactive oxygen species generation and myocardial cellular toxicity due to adriamycin itself. While acute toxicity can result in cardiomyopathy that can in part be reversed by discontinuation of the chemotherapy, late onset of a cardiomyopathy is irreversible. Late onset chronic progressive cardiomyopathy occurs more than 1 year after anthracycline treatment.63,64 With the loss of cardiomyocytes, cardiac function begins to deteriorate with resultant LV wall thinning and in some cases, progressive LV dilation.65,66 Echocardiographic abnormalities may include decreased LV fractional shortening, end-diastolic posterior wall thickness, and mass. Associated would be decreased LV contractility and increased LV afterload. Left ventricular dimension may be increased, normal, or decreased (Figs 66.30A and B; Movie clip 66.30). Strain rate imaging is a new technique to evaluate myocardial mechanics and can detect early changes prior to a decrement in the ejection fraction. This technique will enable early detection of patients at risk of cardiomyopathy and would be useful in managing chemotherapy regimens. Although adults typically develop chronic DCM after anthracycline chemotherapy, children at the end of anthracycline treatment have a DCM, which may then progress to a RCM.66 Afterload increases, in spite of normal-to-reduced blood pressure caused by decreased LV wall thickness and mass. Therefore, the elevated LV afterload reduces the cardiac output to a greater extent


A

1397

B

Figs 66.30A and B: Adriamycin-induced cardiomyopathy. Two-dimensional transesophageal echocardiography. Parasternal long (A) and short; (B) axis views. Left ventricle (LV) is markedly enlarged and severely hypokinetic. The right ventricle (RV) is also very hypokinetic. Arrow points to a catheter in the right heart. (LA: Left atrium; RA: Right atrium) (Movie clip 66.30).

Fig. 66.31: Dilated cardiomyopathy. Two-dimensional transthoracic echocardiography. Left ventricle (LV) short-axis view at the level of the papillary muscles shows decreased rotation of the ventricle in systole and unrotation in diastole. This is a representative frame from the movie clip demonstrating a dilated LV. (RV: Right ventricle). (Movie clip 66.31).

than the reduced LV systolic performance alone. While adriamycin is among the more commonly used agents with significant cardiotoxicity resulting in cardiomyopathy, all chemotherapeutic agents can potentially result in varying degrees of cardiomyopathy too due to their toxicity profile.

Alcohol-Induced Cardiomyopathy Alcohol-induced cardiomyopathy (ACM) is among the leading causes of nonischemic DCM in the United States.67

Long-term heavy alcohol consumption, estimated to be >90 g of alcohol a day for more than 5 years is associated with a higher risk to develop ACM. It often occurs in stages, beginning with a preclinical or asymptomatic stage, and then progressing to a symptomatic stage. The early signs of ACM appear to be LV dilation, with an increase in EDD and increased systolic dimension. It also results in increased LV mass, and modestly increased posterior and septal wall thickening. Associated is an increase in isovolumic relaxation time and deceleration time.68 Diastolic dysfunction thus, appears to be an early finding. However, patients may have both diastolic and/or systolic dysfunction with progression of the condition. Patients may also have some degree of wall thickening which when coupled with LV dilation will serve to offset wall tension. Therefore, many patients may indeed remain in a compensated and asymptomatic state even with LV dysfunction. As the condition progresses, more classical features of DCM are seen with severely impaired systolic function and progressive LV dilation (Fig. 66.31 and Movie clip 66.31).

RESTRICTIVE CARDIOMYOPATHY The distinct morphological and hemodynamic characteristics that separate restrictive from the more common dilated and hypertrophic cardiomyopathies are: 1. Nondilated ventricle (<40 mL/m2) with normal wall thickness (<1–1.2 cm)

1398


2. Rigid ventricular walls with severe LV diastolic dysfunction with restrictive filling leading to elevated filling pressures 3. Biatrial enlargement 4. Normal systolic function in majority of patients 5. Normal pericardium These features are identified with 2D echocardiography as the initial diagnostic test using the Doppler inflow velocities and tissue Doppler techniques. RCM is classified based on the etiology69 as follows: 1. Noninfiltrative disorders—idiopathic RCM, familial cardiomyopathy, HCM, scleroderma, pseudoxanthoma elasticum, and diabetic cardiomyopathy. Familial disease (unrelated to amyloidosis) may overlap with familial HCM and may be caused by some of the same gene mutations. 2. Infiltrative disorders—amyloidosis, sarcoidosis, Gaucher disease, Hurler syndrome, and fatty infiltration 3. Storage diseases—hemochromatosis, Fabry disease (FD), and glycogen storage disease 4. Endomyocardial diseases—for example, endomyocardial fibrosis (EMF) and hypereosinophilic syndrome 5. Radiation and/or drug (e.g. anthracycline) toxicity can cause an RCM or DCM.

Doppler Findings Evaluation by Doppler echocardiography is crucial to the diagnosis of RCM. With advanced disease, often an elevated peak mitral inflow velocity, rapid early mitral inflow deceleration and reduced early annular velocity on tissue Doppler imaging is noted. Pertinent values to be considered in the diagnosis include: 1. The E/A ratio of mitral valve inflow is pathologically elevated typically > 2.070 and the deceleration time is shortened to < 160 milliseconds. 2. Doppler tissue imaging of the mitral annulus also reveals abnormally low diastolic Doppler annular velocities typically < 10 cm/s. 3. The high mitral inflow velocities with low annular velocity also result in a particularly high E/E' ratio > 25. 4. Since restrictive cardiomyopathies are usually global, the RV may also be affected. Hypertrophy can be seen in the right ventricle due to pressure overload and also abnormal tricuspid valve inflow velocities. These can lead to abnormal hepatic vein flow as well. The many different etiologies of RCM also show characteristic patterns on echocardiography.

Amyloid Cardiomyopathy The annual incidence of systemic amyloidosis is approximately 6–10 cases per million of the general population. Evidence suggests that the incidence of cardiac amyloidosis is increasing as the mean life expectancy rises. This may also be due, in part, to improvements in diagnostic modalities that have led to earlier identification of this condition.71 The development of a cardiomyopathy results from the deposition of amyloid within the myocardium. It presents predominantly as a RCM characterized initially by diastolic dysfunction, progressing to profound biventricular systolic dysfunction and arrhythmias. The two most common forms involve deposition of monoclonal light chain fragments in the myocardium (termed primary amyloidosis—AL), or fragments of serum amyloid in secondary amyloidosis (secondary amyloidosis—AA). Endomyocardial biopsy shows interstitial prominence with massive amyloid deposits and varying size myocardial cells often containing vacuoles. In cardiac amyloidosis, echocardiography demonstrates symmetric left ventricular wall thickening typically involving the interventricular septum, small ventricular chambers, thickening of the atrial septum, pericardial effusion, and dilated atria.72,73 Right ventricular diastolic dysfunction may also be present in association with increased right ventricular wall thickness.73 The typical findings of biventricular wall thickness usually precede multichamber dilation seen in the later stages. Intracardiac thrombi may be present in up to 35% of patients with the AL type and up to 15% in other types74 of amyloidosis (Figs 66.32A to C; Movie clips 66.32A and B). With progression of amyloidosis, decreased systolic thickening of the ventricular septum and globally decreased LVEF ensues. The ventricular walls show a granular and brightly reflective sparkling appearance, corresponding to amyloid particle deposition (Figs 66.33A to H; Movie clip 66.33). The cardiac valves typically have a thickened appearance and although their movement is usually normal, valvular regurgitant flow is often detected.72 Interestingly, it has been suggested that the characteristic speckle pattern might not be as obvious when using harmonics on later-generation echocardiography machines.71 The use of echocardiography to differentiate cardiac constriction from RCM, while not definitive, is certainly helpful. The measure of the transvalvular diastolic velocities across the atrioventricular valves is


1399

A

B

C

Figs 66.32A to C: Amyloid. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A) and apical fourchamber (B) views in a 86-year-old female patient with amyloidosis. All chamber walls are echogenic and markedly hypokinetic due to the infiltrative process. The ventricular walls appear thickened because of amyloid deposition, not hypertrophy; (C) Tissue Doppler examination shows diminished mitral E’- and A’-waves (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve) (Movie clips 66.32A and B).

A Figs 66.33A and B

B

1400


C

D

E

F

G

H

Figs 66.33A to H: Amyloidosis. Two-dimensional transthoracic echocardiography. Both the ventricular septum (IVS) and left ventricle (LV) posterior wall (PW) are echogenic and markedly thickened because of amyloid deposition, not hypertrophy. These are visualized in parasternal long- (A systole, B diastole) and short- (C systole, D diastole) axis as well as apical four-chamber (E systole, F diastole) views. LV function is diminished; (G) M-mode examination showing similar findings; (H) Tissue Doppler imaging of the medial mitral annulus shows a low E' velocity of 3.8 cm/s (arrow) consistent with poor longitudinal shortening of LV. (Ao: Aorta; DA: Descending aorta; MV: Mitral valve; RA: Right atrium; RV: Right ventricle; RVW: Right ventricular wall) (Movie clips 66.33A to C).


particularly useful. With constriction, there is a > 25% variation in the mitral and tricuspid velocities during inspiration, while with amyloidosis only the tricuspid velocity changes with little change in the mitral velocity. In addition, in amyloidosis, the change in velocities is concordant between both valves—that is, they increase and decrease at the same time, whereas in constriction the opposite is the rule. These findings are valuable especially in identifying patients who can present in the advanced stages of the disease when systolic function is depressed. These signs of a mixed picture of dilated and restrictive cardiomyopathy are more classical with advanced cardiac amyloidosis.

Fabry Disease Fabry disease (FD) is a lysosomal storage disease, caused by mutations in the gene encoding the enzyme -galactosidase A, resulting in a deficit in enzyme activity. It is X-linked and is characterized by the progressive accumulation of glycosphingolipids. Multiple organs can be affected with the heart, kidneys, and the neurological system in particular being common targets.75 Cardiac involvement is quite frequent and is one of the main causes of death in patients with advanced FD. In the heart, glycosphingolipids’ deposition causes progressive left ventricular hypertrophy (LVH) that can at times mimic the morphological and clinical characteristics of HCM.76

Fig. 66.34: Fabry disease. Two-dimensional transthoracic echocardiography. Arrow shows an echolucency within the myocardium of the ventricular septum, which has been reported in patients with this entity. This finding reflects glycosphingolipids compartmentalization in which the subendocardial layer is spared resulting in an echolucent area. Note that left ventricle (LV) function is poor. Arrowhead in the Movie clip 66.34 points to an intracardiac defibrillator lead. (LA: Left atrium; RA: Right atrium; RV: Right ventricle).

1401

Males with specific gene mutations77 and heterozygous females with low enzyme activity78 can present with a cardiac variant of the disease. It is characterized by progressive concentric LVH, often symmetric and occasionally asymmetric, which correlates with disease severity.79,80 The predominant finding on echocardiography is usually wall thickening without cavity dilatation, with excessive LV mass (up to 240 g/m2) in some male patients.78 While systolic function is usually preserved early on, a pseudonormal filling pattern can be detected by careful Doppler transmitral and pulmonary venous flow analysis, which suggests increased LV filling pressures. A prolongation of the deceleration time is often noted, and Linhart et al. also demonstrated that up to 25% of patients had an impaired LV relaxation pattern, indicating less severe diastolic dysfunction.78,80 The basis of the cardiac hypertrophy in FD is different from that seen in other infiltrative cardiomyopathies where predominantly interstitial infiltration is encountered. The deposits in FD are lysosomal and represent only a small part of the increase in LV mass,77 with true ventricular hypertrophy as a result of neurohormonal influences. Valvular changes are seen and are likely related to the glycosphingolipid deposits and fibrosis of valvular tissue. In the case of the mitral valve, papillary muscle thickening can be found accompanying ventricular hypertrophy. These result in valvular regurgitation that is usually of mild to moderate grade. Among patients with asymmetrical septal hypertrophy, mimicking hypertrophic obstructive cardiomyopathy, the typical systolic anterior motion of the anterior mitral leaflet, can contribute to mitral valve dysfunction. The mitral valve appears to be affected in relatively young subjects, whereas aortic abnormalities appear later. With progressive LVH, aortic root dilatation can be seen. This may be accompanied by the development of aortic valvular regurgitation, which is seldom severe and usually mild (Fig. 66.34; Movie clip 66.34).80 With progression of the disease, myocardial fibrosis ensues and is accompanied by left ventricular systolic dysfunction.81 Strain imaging is particularly useful in estimating myocardial fibrosis. The extent of myocardial fibrosis correlates with the loss in peak systolic strain.81 Therapeutic options include the use of enzyme replacement therapy (ERT) to prevent the extensive deposition of glycosphingolipids. ERT is effective in reversing the microvascular changes in FD by catabolizing the lipid deposits and improving cardiac function in patients with cardiac involvement.82 A recent study has also shown the benefit of emerging echocardiographic techniques in the early diagnosis of

1402


cardiac involvement in FD.83 Through the use of speckle tracking to evaluate myocardial longitudinal strain, the study found that the presence of at least one strain value ≥ −15% demonstrates subclinical myocardial dysfunction in patients with preclinical FD without myocardial hypertrophy. Therefore, this provides evidence of ventricular dysfunction even with the absence of LVH and prior to extensive deposition within the LV. Weidemann et al. have shown that among patients receiving ERT, the maximal benefit occurred in those without myocardial fibrosis.81 Given the emphasis for early diagnosis and institution of treatment, echocardiography arguably has an important role in the management of FD. Especially with the use of emerging techniques to guide therapy, ERT may be able to prevent complications such as LVH, irreversible myocardial fibrosis, lethal arrhythmias, and coronary heart disease.

Hypereosinophilic Cardiomyopathy The WHO published a recent update that outlined the diagnosis of hypereosinophilic syndrome (HES).84 These conditions are characterized by: 1. Persistent marked eosinophilia (>1,500 eosinophils/ mm3); 2. The absence of a primary cause of eosinophilia (such as parasitic or allergic disease); and 3. Evidence of eosinophil-mediated end organ damage. Cardiac involvement unrelated to hypertension, atherosclerosis, or rheumatic disease is identified in 20% of patients (only 6% at the time of initial presentation).85 Typical cardiac findings include endocardial fibrosis and mural thrombus, which is most frequent in the apices of both ventricles and is also characterized by progressive heart failure. The pathophysiology involves eosinophil infiltration of cardiac tissue and release of toxic mediators resulting in endocardial damage and formation of platelet thrombi. These mural thrombi pose a high risk for embolization. Later with disease progression, there is fibrous thickening of the endocardial lining leading to a RCM.86,87 Hence, three stages of pathophysiology—necrosis, thrombosis, and fibrosis are usually identified. Endomyocardial fibrosis (EMF), which was initially described in 1936 by Loeffler, is the most characteristic cardiovascular abnormality.88 Valvular insufficiency can result from mural endocardial thrombosis and fibrosis involving leaflets of the mitral or tricuspid valves.89,90 In addition, entrapment

of the chordae tendineae can occur with progressive scarring, which also results in mitral and/or tricuspid valve regurgitation.

Findings on Transthoracic Echocardiography Echocardiographic evaluation during the necrosis stage is usually normal. The hallmark echocardiographic finding is the persistent obliteration of the apex of the left or right ventricle, or both, by laminar thrombus.91 The common differential diagnosis of LV apical infiltration and obliteration include LV apical thrombus and apical HCM, which can be differentiated by their echocardiographic characteristics. A LV apical thrombus is associated with underlying LV dysfunction and wall motion abnormality. In apical cardiomyopathy, the LV apex is visualized in diastole with obliteration in systole, thus producing the peculiar “ace of spades” configuration. HES, however, shows persistent apical obliteration, mitral valve involvement, and progressive features of a RCM. Resolution of the apical infiltration may sometimes be observed if treated appropriately by medical and surgical intervention. Tricuspid and pulmonary valvular thickening may accompany right ventricular involvement with thrombus formation in the RV apex. Doppler evaluation of the valves enables the estimation of valvular regurgitation and the determination of restrictive physiology (Figs 66.35A to H; Movie clips 66.35A to E).

Contrast Echocardiography Contrast echocardiography may be invaluable in the diagnosis of hypereosinophilic cardiomyopathy enabling it to be differentiated from a thrombus or apical HCM. Specifically since it delineates the shape of LV, it distinguishes between hypertrophy and complete persistent obliteration in these conditions.92

Transesophageal Echocardiography When the transthoracic echo images are poor or limited, transesophageal echocardiography is useful. The deep transgastric views enable visualization of the LV apex and can demonstrate the obliteration of the LV cavity thus confirming the diagnosis.

Endomyocardial Fibrosis In the third stage of HES, significant EMF ensues, resulting in a RCM. It is considered a particularly devastating


A

B

C

D

E

F

Figs 66.35A to F

1403

1404


G

H

Figs 66.35A to H: Loeffler endocarditis. Two-dimensional transthoracic echocardiography. Baseline. (A and B) Modified four-chamber view. (A) Arrowhead shows marked thickening of the tricuspid valve (TV). The arrow points to a large mass in the right ventricular (RV) apex. A small pericardial effusion (PE) is also noted; (B) Color Doppler examination. Arrowhead shows moderate to severe TV regurgitation; (C and D) Aortic (AO) short-axis view; (C) Shows marked thickening of the pulmonary valve (PV); (D) Color Dopplerguided continuous wave Doppler interrogation shows a peak gradient of 48.50 mm Hg consistent with moderate PV stenosis (arrow). After therapy; (E and F) Modified four-chamber view. Show complete normalization of TV and RV apex. Arrowhead points to moderator band. PE is absent; (G and H) Aortic short-axis view; (G) Thickening involving the PV has completely regressed and the valve appears structurally normal (arrowhead); (H) Color Doppler-guided continuous wave Doppler examination shows normal flow velocities across the PV (arrow). (LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium) (Movie clips 66.35A to E). Source: Reproduced with permission from Garg A, Nanda NC, Sungur A, et al. Transthoracic echocardiographic detection of pulmonary valve involvement in Loeffler’s endocarditis. Echocardiography (2013, in press).

Fig. 66.36: Endomyocardial fibrosis in a 62-year-old female with a previous history of mansoni schistosomiasis. Two-dimensional transthoracic echocardiography. Apical four-chamber view shows endocardial thickening and cavity obliteration of both ventricular apices with greater involvement of the left ventricle (LV). The atria are enlarged, which is typical of restrictive cardiomyopathy. The patient improved after heart failure treatment. Source: Reproduced with permission from Carneiro Rde C et al. Endomyocardial fibrosis associated with mansoni schistosomiasis. Rev Soc Bras Med Trop. 2011;44(5):644–5.

disease in the tropical region with an estimated 10 million people affected by it.93 The association between this condition and parasitic infestation has been established by multiple studies such as those of Rashwan et al. and Mocumbi et al. 94,95 Echocardiography is particularly useful in identifying the condition. It is characterized by obliteration of the ventricular apices with progression of the fibrocalcific process, spontaneous echo contrast in the ventricles without significant systolic dysfunction, and significant atrioventricular valve dysfunction due to adhesion of the valve apparatus to the ventricular wall. These are considered the major criteria used to assess the severity of EMF. The minor criteria include severely dilated atria with normal ventricular size, restrictive flow pattern across the mitral or tricuspid valve, and thickening of the anterior mitral leaflet.95 As the condition progresses, more and more of the left ventricular cavity is obliterated, leading to a progressively restrictive physiology.96,97 Evidence of the severest form carries a very poor prognosis, with an estimated survival of 2 years after diagnosis with progressive heart failure being the predominant presentation (Fig. 66.36).


Fig. 66.37: Sarcoidosis. Two-dimensional transthoracic echocardiography. Parasternal long-axis view. Both the ventricular septum (VS) and posterior wall (PW) are echogenic, consistent with myocardial fibrosis. (Ao: Aorta; LA: Left atrium; MV: Mitral valve; RV: Right ventricle) (Movie clip 66.37).

OTHER INFILTRATIVE CARDIOMYOPATHIES Sarcoidosis Sarcoidosis is a systemic disease characterized by the formation of noncaseating granulomas that can infiltrate the myocardium. Cardiac involvement only occurs in approximately 5% of patients with systemic sarcoidosis. Myocardial granulomas with central areas displaying low signal intensity characteristic of fibrosis and a high peripheral signal intensity corresponding to edema are typically seen on cardiac MRI.98 Patients with cardiac sarcoidosis may manifest with a variety of clinical scenarios varying from cardiomyopathy and heart failure to conduction system abnormalities and ventricular tachyarrhythmias. While contemporary diagnosis often entails the use of cardiac MRI, traditional echocardiographic findings are useful in identifying cardiac sarcoidosis. The usual echocardiographic appearance is that of a DCM. The ventricle may be globally hypokinetic or the patchy nature of sarcoid infiltration of the heart may result in regional wall motion abnormalities. With edema or infiltration, mild wall thickening may also be present. This is noted on echocardiography by the presence of bright shadows consistent with infiltration. Typically with progression, areas of wall thinning are seen, most commonly in the ventricular septum,

1405

associated with scarring. Specifically, the thinning of the basal anterior septum, while relatively uncommon, is very characteristic of cardiac sarcoidosis.99 Interestingly, the finding of anterior septal thinning does not correlate with conduction system abnormalities, namely varying degrees of AV block, which are commonly seen in this condition (Fig. 66.37; Movie clip 66.37).99 In the absence of LV thinning, ventricular wall thickness is usually preserved. In fact, Matsumori et al. have described a presentation similar to HCM in some patients with sarcoidosis.100 This is, however, a relatively rare finding. A nonspecific, but commonly found, feature on echocardiography is diastolic dysfunction. This may be found early on with initial interstitial inflammation, when systolic function may still be normal.101 Valvular involvement is rare and might be seen as sequelae of DCM when present.

Hemochromatosis Hemochromatosis represents an iron overload disorder characterized by the accumulation of iron within various cells, including cardiac myocytes. Cardiac manifestations of hemochromatosis are characterized by systolic dysfunction, and cardiac MRI can detect and quantify myocardial iron infiltration using T2 weighted imaging. Liver biopsy is the definitive test for iron overload.102 Serum transferrin saturation is typically > 45% and elevated serum ferritin levels are seen, which help confirm the diagnosis of hemochromatosis. Although cardiac MRI is a superior imaging modality for the diagnosis of cardiac hemochromatosis, TTE is useful for following disease response to chelation therapy and/or phlebotomy. The echocardiographic features of hemochromatosis include mild LV dilatation, LV systolic dysfunction, normal wall thickness, and biatrial enlargement.103 The degree of iron deposition in the myocardium correlates with the degree of LV dysfunction.

INFECTIOUS AND METABOLIC CARDIOMYOPATHIES Infectious Cardiomyopathy Septic Cardiomyopathy Acute and reversible cardiac dysfunction commonly occurs in patients with septic shock. In the absence of other causes of cardiomyopathy, there are two main

1406


A

C

factors that contribute to cardiac depression in the setting of sepsis. Decreased RV function, presumably related to both acute pulmonary hypertension from acute lung injury and reduced RV contractility, act to decrease the LV filling pressures, and hence decrease cardiac output. In addition, a direct depression in LV contractility due to circulating cytokines also decreases cardiac output in sepsis. Exposure of myocardial cells to inflammatory cytokines, mainly circulating tumor necrosis factor alpha (TNF-) and interleukin-1B (IL-1B), have a direct negative inotropic effect on cardiac myocytes mainly through increases in intracellular cGMP and nitric oxide (NO). Mitochondrial dysfunction and decreased myofilament response to Ca2+ secondary to troponin I phosphorylation have also been implicated.104

B

Figs 66.38A to C: Septicemic myocarditis. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A) and apical fourchamber (B) views. This patient with streptococcal pneumonia developed poor biventricular function consistent with myocarditis; (C) Apical four-chamber view. Further deterioration of ventricular function was noted on the next day and the patient succumbed in the next few days from multiorgan failure. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; PW: Posterior wall; RA: Right atrium; RV: Right ventricle; VS: Ventricular septum) (Movie clips 66.38A to C).

Echocardiographic Features of Septic Cardiomyopathy Unlike cardiogenic shock, which typically manifests as globally reduced LV function with pronounced LV dilatation and a restrictive pattern of LV inflow (pulsed Doppler of the mitral valve showing high E-wave velocities and low A-wave velocities suggestive of high LV filling pressures), septic cardiomyopathy manifests as global LV dysfunction with minimal LV dilatation and mitral inflow velocities suggesting near-normal LV filling pressures. There is often pronounced yet reversible RV dysfunction and RV dilatation (Figs 66.38A to C; Movie clips 66.38A to C).104


Septic Cardiomyopathy

Cardiogenic Shock

LV function

Globally reduced

Often globally reduced

LV dilatation

Mild

Severe

Mitral inflow velocities

Mostly normal

Restrictive pattern— high E-wave velocities, low A-wave velocities

RV involvement

Often decreased RV systolic function and RV dilatation

Less common

Reversibility

Yes (days)

Depends on etiology

1407

of complex carbohydrate metabolism, storage disorders, neuromuscular diseases, organic acidemias, and other diseases such as congenital disorders of glycosylation (CDG) and disorders of metal and pigment metabolism (Wilson disease, hemochromatosis, Dubin–Johnson syndrome).109 Children and young adults who develop cardiomyopathy should be evaluated for underlying inherited metabolic disorders if no obvious other sources of cardiomyopathy are found.

Echocardiographic Features of Metabolic Cardiomyopathies

The degree of global dysfunction in septic cardiomyopathy may be masked by severe peripheral vasodilatation causing significantly reduced afterload, thereby appearing as if cardiac output is not significantly reduced. However, once patients receive restoration of normal afterload with fluid resuscitation and/or vasopressor support, the degree of sepsis-induced LV dysfunction is often unmasked. Once the diagnosis of septic cardiomyopathy is made, serial bedside transthoracic echocardiograms may be obtained to assess the degree of LV and RV dysfunction in response to treatment.

Cardiomyopathies in pediatric patients with inborn errors in metabolism can manifest as hypertrophic or dilated ventricles with globally reduced systolic function. Restrictive patterns are less common in this patient population. However, patients with cardiomyopathies due to disorders of metal metabolism often have a restrictive pattern. The typical features of RCM, namely biatrial enlargement, severe diastolic dysfunction of the LV, and consequent right ventricular hypertrophy have been discussed previously.

HIV-Associated Cardiomyopathy

Diabetic cardiomyopathy is diagnosed when ventricular dysfunction develops in diabetic patients, in the absence of coronary atherosclerosis and hypertension.110,111 There has been a reported increased risk of heart failure in diabetic patients after matching them for age, blood pressure, weight, cholesterol, and CAD.112 There has also been a significant association between diabetes and diastolic dysfunction leading to CHF with preserved systolic function.113

Cardiac abnormalities can be found in up to 44% of patients with HIV.105 HIV is associated with LV systolic dysfunction in addition to DCM, although additional cardiac abnormalities may also be present. Specifically, pericardial effusion, pulmonary arterial hypertension, infective endocarditis, and intracardiac masses due to lymphoma and Kaposi sarcoma have all been described in HIV patients. DCM and LV dysfunction are often associated with myocarditis with various viral (including HIV), fungal, and atypical mycobacterial organisms. Toxoplasma gondii has also been implicated.106-108 In addition, ischemic heart disease and the development of LV diastolic abnormalities are associated with highly active antiretroviral therapy (HAART).106

Metabolic Cardiomyopathy Metabolic cardiomyopathies encompass a wide range of inherited metabolic disorders and a wide spectrum of other pathological conditions. Inherited metabolic disorders often present in childhood and include defects in mitochondrial long-chain fatty acid oxidation, carnitine deficiency disorders, respiratory chain defects, disorders

Diabetic Cardiomyopathy

Two-Dimensional Echo Echocardiography can be used to ascertain the systolic and diastolic function. Diastolic dysfunction is depicted by reduced early peak mitral inflow velocities at annular septal and lateral levels in early diastole, as noted on Doppler echo. Increased myocardial reflectivity in patients with diabetes-related heart disease has also been reported (Figs 39A to C).114

CARCINOID HEART DISEASE The carcinoid syndrome is a constellation of signs and symptoms that are seen with neuroendocrine tumors,

1408


A

C arising from the enterochromaffin cells most often in the gastrointestinal tract. These tumors are malignant with an incidence of around 1.2–2.1 per 100,000 of the general population.115 They are characterized by the production of vasoactive substances such as serotonin, 5-hydroxytryptamine, bradykinin, tachykinin, and prostaglandins, which result in the typical clinical features of flushing, diarrhea, bronchospasm, and hypotension.115,116 Carcinoid heart disease is seen in > 50% of patients with carcinoid syndrome.117 In approximately 20% of patients, carcinoid heart disease is the primary presentation of metastatic carcinoid disease. Historically, the association between carcinoid tumors and specific cardiac disease was described in the 1950s.118 The echocardiographic features of carcinoid heart disease were well described in the 1980s and used reliably in its diagnosis.119,120 Cardiac involvement is predominantly right-sided as the lungs filter the tumor products before they reach the left atrium. It is characterized by plaque-like deposits of fibrous tissue, typically on the endocardium of the right-

B

Figs 66.39A to C: Diabetic cardiomyopathy. Doppler mitral inflow and Doppler tissue imaging in a 79-year-old female patient. (A) Peak early mitral inflow diastolic velocity (E) measured 86.2 cm/s in this patient; (B and C) Peak mitral annular septal (Es) and lateral (El) velocities in early diastole measured 4.07 cm/s (B) and 4.47 cm/s (C), respectively. The ratio of E to Es and E to El calculates to be 21.17 (normal < 15) and 19.28 (normal < 12), respectively. The ratio of E to average of Es and El is 20.18 (normal < 13). These findings are indicative of left ventricle (LV) diastolic dysfunction with increased left-sided filling pressures.

sided valvular cusps and leaflets as well as the RA and RV.121 The involvement of the tricuspid valve typically results in hemodynamically significant regurgitation and, less frequently, in valvular stenosis. The pulmonary valve, which is also commonly affected, develops a combination of stenosis and regurgitation. Hemodynamically relevant pulmonic valve stenosis is more frequently noted than tricuspid stenosis. This is because, the orifice of the pulmonic valve is much smaller and consequently, plaque deposition on the pulmonary valve and within the pulmonic annulus and sinuses results in narrowing of the pulmonic root. Left-sided involvement occurs in < 10% and is characterized by valve thickening and regurgitation without concurrent stenosis.122 Hepatic metastases are often associated with carcinoid heart disease. Tumor growth within the liver allows large quantities of humoral tumor products to reach the RV without being inactivated by the first-pass metabolism in the liver, which is thought to be responsible for cardiac plaque formation.123,124


If carcinoid valvular heart disease involves the mitral or aortic valve, a right-to-left shunt or a primary bronchial carcinoid is frequently found. Alternatively, left-sided valve disease may occur in the absence of these conditions if the carcinoid syndrome is severe and poorly controlled.125 A recent multimodality imaging study of 52 patients with carcinoid heart disease showed the presence of a patent foramen ovale in 13 of 15 (87%) patients with left-sided carcinoid involvement further giving credence to the theory of right-to-left shunts being responsible for left heart involvement.126

Echocardiographic Features On 2D echocardiography, the tricuspid valve leaflets are typically thickened and shortened. The leaflets become increasingly retracted with progression of the disease, resulting in reduced mobility. The septal and the anterior leaflets are usually predominantly affected, whereas the posterior leaflet may exhibit relatively preserved mobility. Severe tricuspid regurgitation results in advanced stages of tricuspid valve disease as the leaflets become fixed in a semi-open position. There is also some degree of concomitant stenosis due to a fixed orifice. Color flow Doppler assessment of the hepatic veins may show systolic flow reversal, consistent with severe tricuspid regurgitation. On continuous wave Doppler tracings, severe tricuspid regurgitation is characterized by a daggershaped profile with an early peak velocity and a rapid decline, indicating rapid pressure equalization between the right-sided cardiac chambers. The peak regurgitant velocity may be increased due to coexistent pulmonic stenosis. The presence of a prolonged pressure half-time of the tricuspid inflow indicates associated tricuspid valve stenosis. Increases in tricuspid inflow velocities and the mean gradient across the tricuspid valve result from a combination of valvular stenosis and increased blood flow through the valve owing to the regurgitant volume.127 The pulmonary valve cusps appear thickened with retraction and reduced mobility. The cusps may be difficult to visualize if they are severely retracted. Constriction of the pulmonary annulus as a result of plaque deposition may also be observed. Doppler echocardiographic assessment of the pulmonary valve is particularly helpful because demonstration of the anatomical changes may be challenging. Increased systolic velocities on continuous wave Doppler examination are consistent with pulmonary stenosis, whereas a dense regurgitant spectral profile with a short deceleration time is typical for severe regurgitation.

1409

Chronic tricuspid and pulmonic valve regurgitation results in progressive volume overload of the right-sided chambers. The hemodynamic situation can be further compromised by pressure overload due to pulmonic stenosis. As a consequence, the RA and ventricle become increasingly dilated. Furthermore, hypokinesis of the RV may be apparent in advanced stages of the disease. Consequently, patients present with right ventricular failure and signs of volume overload characterized by pedal edema, pulsatile liver, and effort intolerance. While isolated left ventricular dysfunction is not seen per se, the presence of right ventricular failure results in a low systemic output state with diminution of the cardiac output. Left-sided valvular involvement is infrequent. It is characterized by diffuse valve thickening and retraction with reduced mobility and regurgitation, but without significant stenosis (Figs 66.40A to C, Movies 66.40A to C). Dumaswala et al have elegantly illustrated the incremental value of 3D echocardiography in carcinoid heart disease.128 Three-dimensional echocardiography can allow for better assessment of (a) valvular structure, (b) severity of valvular disease, (c) extent of cardiac involvement, and (d) metastatic lesions. It is particularly useful as it permits evaluation of all three leaflets of the tricuspid and pulmonary valves. This is not so with 2D echocardiography wherein only the anterior and septal leaflets of the tricuspid valve and the anterior (left anterior) and left (posterior) leaflets of the pulmonary valve can be visualized. Estimation of the effective regurgitant orifice area is made using the proximal isovelocity surface area (PISA) method by 2D transthoracic echocardiography (2D TTE), which depends on the assumption that flow convergence is hemispheric, although this does not hold true at most times.129 The vena contracta method, which is also used to find the area of regurgitation by 2D TTE, depends on the assumption that the area of regurgitation is circular or elliptical, which is also not the case in most circumstances. The measurement of the vena contracta is also more accurate with 3D imaging since it permits visualization of the entire regurgitant jet. Thus, the quantification of valvular regurgitation, particularly tricuspid and pulmonary, which are more common in carcinoid heart disease, is more reliable with 3D echocardiography. Further, the visualization of endocardial deposits is superior with 3D echocardiography as is the evaluation of hepatic metastasis in the subcostal views. These help improve the diagnostic accuracy while also identifying the anatomical extent of endocardial deposits (Figs 66.41A to K; Movie clips 66.41A to F).

1410


The pulmonary valve appeared thickened, retracted, and immobile in 36 patients (49%) and could not be visualized in an additional 29 patients (39%). Pulmonic stenosis was identified in 25 patients (53%) by Doppler echocardiography.

Enlargement of the RA and the RV was seen in 67 (91%) and 65 (88%) patients, respectively. Four patients (5%) exhibited impaired right ventricular systolic function. Left-sided valve lesions were only found in five patients (7%). Presence of myocardial carcinoid metastases was

A

B

C

Figs 66.40A to C: Carcinoid disease. Two-dimensional transthoracic echocardiography. (A) Apical four-chamber view shows systolic noncoaptation of thickened anterior (1) and septal (2) leaflets of tricuspid valve (TV); (B) Color Doppler examination shows severe tricuspid regurgitation (arrowhead) resulting from systolic noncoaptation of TV leaflets. Tricuspid regurgitation (TR) jet practically fills the right atrium (RA); (C) Aortic (Ao) short-axis view shows severe pulmonary regurgitation (PR) with the PR jet extending all the way to the TV level. (LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle) (Movie clips 66.40A to C). Source: Reproduced with permission from Ref. 128. 66.40A to C).

A

B

Figs 66.41A and B


C

D

E

F

G

H

Figs 66.41C to H

1411

1412


J

I

K Figs 66.41A to K: Carcinoid disease. Live/real time three-dimensional transthoracic echocardiography. (A) 1, 2, and 3 represent thickened anterior, septal, and inferior (posterior) leaflets of the tricuspid valve (TV), respectively, showing a very large area of noncoaptation in systole (Movie clip 66.41A, part 1). Movie clip 66.41A part 2 shows QLAB images. Movie clip 66.41A part 3 shows color Doppler assessment of TV regurgitation (TR). The vena contracta (VC; arrowhead) is very large, measuring 2.51 cm2, consistent with torrential TR; (B) 1, 2, and 3 represent thickened anterior (left anterior), left (posterior), and right (right anterior) leaflets of the pulmonary valve (PV), respectively, (Movie clip 66.41B part 1). In Movie clip 66.41B part 2 the arrowhead points to noncoaptation of the PV leaflets in diastole. Movie clip 66.41B part 3 shows color Doppler assessment of pulmonary regurgitation (PR). The VC (arrowhead) is large, measuring 0.7 cm2, consistent with severe PR; (C to E) Arrowhead shows a prominent, localized echogenic carcinoid deposit involving the interatrial septum (IAS); (F) The arrowhead demonstrates a carcinoid deposit lining the wall of the inferior vena cava (IVC); (G and H) QLAB. Upper arrowheads point to the carcinoid deposit involving the right atrium (RA) superior wall. Lower arrowhead views the same plaque en-face. It measured 2.02 × 0.85 cm, area = 1.36 cm2; (I to K) Subcostal examination; (I) A large carcinoid metastasis, bounded by dots, is noted in the liver (L). QLAB sections taken at two different levels show the extent of hemorrhage/necrosis (arrowheads) in the lesion; (J) Another liver metastasis (M, dots) is seen encroaching the RA and IVC; (K) Examination of another patient with known simple L cysts. Arrowheads point to some of the cysts, which are generally completely echolucent with thin, well-defined borders. These features distinguish them from a carcinoid lesion, where the echolucencies do not involve the whole cyst and the borders are less well defined and are thickened. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; PA: Pulmonary artery; RV: Right ventricle) (Movie clips 66.41A parts 1 to 3, 66.41B parts 1 to 3, 66.41C to F, 66.41I parts 1 and 2, 66.41J and 66.41K).

Pellikka et al. have described the spectrum of the echocardiographic changes and the frequency of their detection in an elegant series of 74 patients with carcinoid heart disease treated at the Mayo Clinic.122 Tricuspid

regurgitation was the predominant finding present in 72 patients (97%) by 2D criteria and all 69 patients who underwent Doppler examination. In 62 patients (90%), the degree of regurgitation was moderate or severe.


demonstrated in three patients (4%) and small pericardial effusions without hemodynamic significance were seen in 10 patients (14%). Thus, carcinoid heart disease can have varied features that are well defined and diagnosed through echocardiography. While left-sided involvement is rare, the presence of metastatic masses in the LV and mitral valve disease are concerning features that warrant aggressive therapy. Further, cardiac output is affected due to right ventricular dysfunction rather than left ventricular involvement.

REFERENCES 1. Richardson P, McKenna W, Bristow M, et al. Report of the 1995 World Health Organization/International Society and Federation of Cardiology Task Force on the Definition and Classification of cardiomyopathies. Circulation. 1996;93(5):841–2. 2. Maron BJ, Towbin JA, Thiene G, et al.; American Heart Association; Council on Clinical Cardiology, Heart Failure and Transplantation Committee; Quality of Care and Outcomes Research and Functional Genomics and Translational Biology Interdisciplinary Working Groups; Council on Epidemiology and Prevention. Contemporary definitions and classification of the cardiomyopathies: an American Heart Association Scientific Statement from the Council on Clinical Cardiology, Heart Failure and Transplantation Committee; Quality of Care and Outcomes Research and Functional Genomics and Translational Biology Interdisciplinary Working Groups; and Council on Epidemiology and Prevention. Circulation. 2006;113(14):1807–16. 3. Elliott P, Andersson B, Arbustini E, et al. Classification of the cardiomyopathies: a position statement from the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. Eur Heart J. 2008;29(2):270–6. 4. Lang RM, Bierig M, Devereux RB, et al. Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recommendations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 5. Kashani A, Barold SS. Significance of QRS complex duration in patients with heart failure. J Am Coll Cardiol. 2005;46(12):2183–92. 6. Adabag S, Roukoz H, Anand IS, et al. Cardiac resynchronization therapy in patients with minimal heart failure: a systematic review and meta-analysis. J Am Coll Cardiol. 2011;58(9):935–41.

1413

7. Dini FL, Cortigiani L, Baldini U, et al. Prognostic value of left atrial enlargement in patients with idiopathic dilated cardiomyopathy and ischemic cardiomyopathy. Am J Cardiol. 2002;89(5):518–23. 8. Kircher BJ, Himelman RB, Schiller NB. Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava. Am J Cardiol. 1990; 66(4):493–6. 9. Pozzoli M, Capomolla S, Sanarico M, et al. Doppler evaluations of left ventricular diastolic filling and pulmonary wedge pressure provide similar prognostic information in patients with systolic dysfunction after myocardial infarction. Am Heart J. 1995;129(4): 716–25. 10. Capomolla S, Pinna GD, Febo O, et al. Echo-Doppler mitral flow monitoring: an operative tool to evaluate day-to-day tolerance to and effectiveness of beta-adrenergic blocking agent therapy in patients with chronic heart failure. J Am Coll Cardiol. 2001;38(6):1675–84. 11. Rihal CS, Nishimura RA, Hatle LK, et al. Systolic and diastolic dysfunction in patients with clinical diagnosis of dilated cardiomyopathy. Relation to symptoms and prognosis. Circulation. 1994;90(6):2772–9. 12. Rossi A, Dini FL, Faggiano P, et al. Independent prognostic value of functional mitral regurgitation in patients with heart failure. A quantitative analysis of 1256 patients with ischaemic and non-ischaemic dilated cardiomyopathy. Heart. 2011;97(20):1675–80. 13. Abramson SV, Burke JF, Kelly JJ Jr, et al. Pulmonary hypertension predicts mortality and morbidity in patients with dilated cardiomyopathy. Ann Intern Med. 1992;116(11):888–95. 14. Armstrong WF, Ryan T. Feigenbaum’s Echocardiography. 7th ed. Philadelphia: Lippincott, Williams & Wilkins; 2010:517. 15. Nishimura RA, Hayes DL, Holmes DR Jr, et al. Mechanism of hemodynamic improvement by dual-chamber pacing for severe left ventricular dysfunction: an acute Doppler and catheterization hemodynamic study. J Am Coll Cardiol. 1995;25(2):281–8. 16. Knappe D, Pouleur AC, Shah AM, et al. Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy Investigators. Dyssynchrony, contractile function, and response to cardiac resynchronization therapy. Circ Heart Fail. 2011;4(4):433–40. 17. Lee CH, Hung KC, Chen CC, et al. A novel echocardiographic parameter for predicting the ischemic etiology of cardiomyopathy and its prognosis in patients with congestive heart failure. J Am Soc Echocardiogr. 2011;24(12):1349–57. 18. Díaz-Infante E, Mont L, Leal J, et al.; SCARS Investigators. Predictors of lack of response to resynchronization therapy. Am J Cardiol. 2005;95(12):1436–40. 19. Gradaus R, Stuckenborg V, Löher A, et al. Diastolic filling pattern and left ventricular diameter predict response and prognosis after cardiac resynchronisation therapy. Heart. 2008;94(8):1026–31.

1414


20. Dujardin KS, Enriquez-Sarano M, Rossi A, et al. Echocardiographic assessment of left ventricular remodeling: are left ventricular diameters suitable tools? J Am Coll Cardiol. 1997;30(6):1534–41. 21. Carluccio E, Biagioli P, Alunni G, et al. Presence of extensive LV remodeling limits the benefits of CRT in patients with intraventricular dyssynchrony. JACC Cardiovasc Imaging. 2011;4(10):1067–76. 22. Bax JJ, Schinkel AF, Boersma E, et al. Extensive left ventricular remodeling does not allow viable myocardium to improve in left ventricular ejection fraction after revascularization and is associated with worse long-term prognosis. Circulation. 2004;110:II18–22. 23. Burkett EL, Hershberger RE. Clinical and genetic issues in familial dilated cardiomyopathy. J Am Coll Cardiol. 2005;45(7):969–81. 24. Codd MB, Sugrue DD, Gersh BJ, et al. Epidemiology of idiopathic dilated and hypertrophic cardiomyopathy. A population-based study in Olmsted County, Minnesota, 1975-1984. Circulation. 1989;80(3):564–72. 25. Mielniczuk LM, Williams K, Davis DR, et al. Frequency of peripartum cardiomyopathy. Am J Cardiol. 2006; 97(12): 1765–8. 26. Demakis JG, Rahimtoola SH. Peripartum cardiomyopathy. Circulation. 1971;44(5):964–8. 27. Hibbard JU, Lindheimer M, Lang RM. A modified definition for peripartum cardiomyopathy and prognosis based on echocardiography. Obstet Gynecol. 1999;94(2):311–16. 28. Pearson GD, Veille JC, Rahimtoola S, et al. Peripartum cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) workshop recommendations and review. JAMA. 2000;283(9):1183–8. 29. Chapa JB, Heiberger HB, Weinert L, et al. Prognostic value of echocardiography in peripartum cardiomyopathy. Obstet Gynecol. 2005; 105(6):1303–8. 30. Karaye KM. Right ventricular systolic function in peripartum and dilated cardiomyopathies. Eur J Echocardiogr. 2011; 12(5):372–4. 31. Lampert MB, Weinert L, Hibbard J, et al. Contractile reserve in patients with peripartum cardiomyopathy and recovered left ventricular function. Am J Obstet Gynecol. 1997;176(1 Pt 1):189–95. 32. Fett JD, Fristoe KL, Welsh SN. Risk of heart failure relapse in subsequent pregnancy among peripartum cardiomyopathy mothers. Int J Gynaecol Obstet. 2010;109(1):34–6. 33. Ritter M, Oechslin E, Sütsch G, et al. Isolated noncompaction of the myocardium in adults. Mayo Clin Proc. 1997;72(1):26–31. 34. Weiford BC, Subbarao VD, Mulhern KM. Noncompaction of the ventricular myocardium. Circulation. 2004;109(24): 2965–71. 35. Jenni R, Oechslin E, Schneider J, et al. Echocardiographic and pathoanatomical characteristics of isolated left ventricular non-compaction: a step towards classification as a distinct cardiomyopathy. Heart. 2001;86(6):666–71.

36. Božić I, Fabijanić D, Carević V, et al. Echocardiography in the diagnosis and management of isolated left ventricular non-compaction: case reports and review of the literature. J Clin Ultrasound. 34:416–21. 37. Chin TK, Perloff JK, Williams RG, et al. Isolated noncompaction of left ventricular myocardium. A study of eight cases. Circulation. 1990;82(2):507–13. 38. Bodiwala K, Miller AP, Nanda NC, et al. Live threedimensional transthoracic echocardiographic assessment of ventricular noncompaction. Echocardiography. 2005; 22(7):611–20. 39. Baker GH, Pereira NL, Hlavacek AM, et al. Transthoracic real-time three-dimensional echocardiography in the diagnosis and description of noncompaction of ventricular myocardium. Echocardiography. 2006;23(6):490–4. 40. Oechslin EN, Attenhofer Jost CH, Rojas JR, et al. Longterm follow-up of 34 adults with isolated left ventricular noncompaction: a distinct cardiomyopathy with poor prognosis. J Am Coll Cardiol. 2000;36(2):493–500. 41. Main ML, Grayburn PA. Clinical applications of transpulmonary contrast echocardiography. Am Heart J. 1999; 137(1):144–53. 42. Mulvagh SL, DeMaria AN, Feinstein SB, et al. Contrast echocardiography: current and future applications. J Am Soc Echocardiogr. 2000;13(4):331–42. 43. Bybee KA, Kara T, Prasad A, et al. Systematic review: transient left ventricular apical ballooning: a syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med. 2004;141(11):858–65. 44. Abe Y, Kondo M, Matsuoka R, et al. Assessment of clinical features in transient left ventricular apical ballooning. J Am Coll Cardiol. 2003;41(5):737–42. 45. Desmet WJ, Adriaenssens BF, Dens JA. Apical ballooning of the left ventricle: first series in white patients. Heart. 2003;89(9):1027–31. 46. Kurowski V, Kaiser A, von Hof K, et al. Apical and midventricular transient left ventricular dysfunction syndrome (tako-tsubo cardiomyopathy): frequency, mechanisms, and prognosis. Chest. 2007;132(3):809–16. 47. Manzanal A, Ruiz L, Madrazo J, et al. Inverted Takotsubo cardiomyopathy and the fundamental diagnostic role of echocardiography. Tex Heart Inst J. 2013;40(1):56–9. 48. Eitel I, von Knobelsdorff-Brenkenhoff F, Bernhardt P, et al. Clinical characteristics and cardiovascular magnetic resonance findings in stress (takotsubo) cardiomyopathy. JAMA. 2011;306(3):277–86. 49. Jeong YH, Choi KJ, Song JM, et al. Diagnostic approach and treatment strategy in tachycardia-induced cardiomyopathy. Clin Cardiol. 2008;31(4):172–8. 50. Gheorghiade M, Bonow RO. Chronic heart failure in the United States: a manifestation of coronary artery disease. Circulation. 1998;97(3):282–9. 51. Thiene G, Corrado D, Basso C. Arrhythmogenic right ventricular cardiomyopathy/dysplasia. Orphanet J Rare Dis. 2007;2:45. 52. Basso C, Thiene G, Corrado D, et al. Arrhythmogenic right ventricular cardiomyopathy. Dysplasia, dystrophy, or myocarditis? Circulation. 1996; 94(5):983–91.


53. Marcus FI, Fontaine GH, Guiraudon G, et al. Right ventricular dysplasia: a report of 24 adult cases. Circulation. 1982;65(2):384–98. 54. McKenna WJ, Thiene G, Nava A, et al. Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy. Task Force of the Working Group Myocardial and Pericardial Disease of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology. Br Heart J. 1994;71(3):215–18. 55. Scognamiglio R, Fasoli G, Nava A, et al. Contribution of cross-sectional echocardiography to the diagnosis of right ventricular dysplasia at the asymptomatic stage. Eur Heart J. 1989; 10(6):538–42. 56. Foale R, Nihoyannopoulos P, McKenna W, et al. Echocardiographic measurement of the normal adult right ventricle. Br Heart J. 1986;56(1):33–44. 57. Yoerger DM, Marcus F, Sherrill D, et al. Multidisciplinary Study of Right Ventricular Dysplasia Investigators. Echocardiographic findings in patients meeting task force criteria for arrhythmogenic right ventricular dysplasia: new insights from the multidisciplinary study of right ventricular dysplasia. J Am Coll Cardiol. 2005;45(6):860–5. 58. Marcus FI, McKenna WJ, Sherrill D, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/ dysplasia: proposed modification of the Task Force Criteria. Eur Heart J. 2010;31(7):806–14. 59. Teske AJ, Cox MG, De Boeck BW, et al. Echocardiographic tissue deformation imaging quantifies abnormal regional right ventricular function in arrhythmogenic right ventricular dysplasia/cardiomyopathy. J Am Soc Echocardiogr. 2009;22(8):920–7. 60. Kjaergaard J, Hastrup Svendsen J, Sogaard P, et al. Advanced quantitative echocardiography in arrhythmogenic right ventricular cardiomyopathy. J Am Soc Echocardiogr. 2007; 20(1):27–35. 61. Prakasa KR, Dalal D, Wang J, et al. Feasibility and variability of three dimensional echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy. Am J Cardiol. 2006;97(5):703–9. 62. Lipshultz SE, Alvarez JA, Scully RE. Anthracycline associated cardiotoxicity in survivors of childhood cancer. Heart. 2008;94(4):525–33. 63. Grenier MA, Lipshultz SE. Epidemiology of anthracycline cardiotoxicity in children and adults. Semin Oncol. 1998; 25(4 Suppl 10):72–85. 64. Giantris A, Abdurrahman L, Hinkle A, et al. Anthracyclineinduced cardiotoxicity in children and young adults. Crit Rev Oncol Hematol. 1998;27(1):53–68. 65. Lipshultz SE, Colan SD, Gelber RD, et al. Late cardiac effects of doxorubicin therapy for acute lymphoblastic leukemia in childhood. N Engl J Med. 1991;324(12):808–15. 66. Lipshultz SE, Lipsitz SR, Sallan SE, et al. Chronic progressive cardiac dysfunction years after doxorubicin therapy for childhood acute lymphoblastic leukemia. J Clin Oncol. 2005;23(12):2629–36.

1415

67. Piano MR. Alcoholic cardiomyopathy: incidence, clinical characteristics, and pathophysiology. Chest. 2002;121(5): 1638–50. 68. Lazareviç, AM, Nakatani, S, Neškoviç, AN, et al. Early changes in left ventricular function in chronic asymptomatic alcoholics: relation to the duration of heavy drinking. J Am Coll Cardiol. 2000;35:1599–606 69. Kushwaha SS, Fallon JT, Fuster V. Restrictive cardiomyopathy. N Engl J Med. 1997;336(4):267–76. 70. Armstrong WF, Ryan T. Feigenbaum’s Echocardiography. 7th ed. Philadelphia: Lippincott, Williams & Wilkins; 2010: 556. 71. Sharma N, Howlett J. Current state of cardiac amyloidosis. Curr Opin Cardiol. 2013;28(2):242–8. 72. Siqueira-Filho AG, Cunha CL, Tajik AJ, et al. M-mode and two-dimensional echocardiographic features in cardiac amyloidosis. Circulation. 1981;63(1):188–96. 73. Klein AL, Hatle LK, Burstow DJ, et al. Comprehensive Doppler assessment of right ventricular diastolic function in cardiac amyloidosis. J Am Coll Cardiol. 1990;15(1):99– 108. 74. Feng D, Syed IS, Martinez M, et al. Intracardiac thrombosis and anticoagulation therapy in cardiac amyloidosis. Circulation. 2009;119(18):2490–7. 75. AADELFA (Asociación Argentina de estudio de enfermedad de Fabry y otras enfermedades lisosomales): Evaluation of patients with Fabry disease in Argentina. Medicina. 2010;70:37–43. 76. Tanaka H, Adachi K, Yamashita Y, et al. Four cases of Fabry’s disease mimicking hypertrophic cardiomyopathy. J Cardiol. 1988;18(3):705–18. 77. von Scheidt W, Eng CM, Fitzmaurice TF, et al. An atypical variant of Fabry’s disease with manifestations confined to the myocardium. N Engl J Med. 1991;324(6):395–9. 78. Whybra C, Kampmann C, Willers I, et al. AndersonFabry disease: clinical manifestations of disease in female heterozygotes. J Inherit Metab Dis. 2001;24(7):715–24. 79. MacDermot KD, Holmes A, Miners AH. Anderson-Fabry disease: clinical manifestations and impact of disease in a cohort of 98 hemizygous males. J Med Genet. 2001; 38(11):750–60. 80. Linhart A, Palecek T, Bultas J, et al. New insights in cardiac structural changes in patients with Fabry’s disease. Am Heart J. 2000;139(6):1101–08. 81. Weidemann F, Niemann M, Breunig F, et al. Longterm effects of enzyme replacement therapy on fabry cardiomyopathy: evidence for a better outcome with early treatment. Circulation. 2009;119(4):524–9. 82. Weidemann F, Breunig F, Beer M, et al. Improvement of cardiac function during enzyme replacement therapy in patients with Fabry disease: a prospective strain rate imaging study. Circulation. 2003;108(11):1299–301. 83. Saccheri MC, Cianciulli TF, Lax JA, et al.; AADELFA. TwoDimensional Speckle Tracking Echocardiography for Early Detection of Myocardial Damage in Young Patients with Fabry Disease. Echocardiography. 2013. 84. Gotlib J. World Health Organization-defined eosinophilic disorders: 2012 update on diagnosis, risk stratification, and management. Am J Hematol. 2012;87(9):903–14.

1416


85. Ogbogu PU, Bochner BS, Butterfield JH, et al. Hypereosinophilic syndrome: a multicenter, retrospective analysis of clinical characteristics and response to therapy. J Allergy Clin Immunol. 2009;124(6):1319–25.e3. 86. Fauci AS, Harley JB, Roberts WC, et al. NIH conference. The idiopathic hypereosinophilic syndrome. Clinical, pathophysiologic, and therapeutic considerations. Ann Intern Med. 1982; 97(1):78–92. 87. Weller PF, Bubley GJ. The idiopathic hypereosinophilic syndrome. Blood. 1994;83(10):2759–79. 88. Loeffler W. Endocarditis parietalis fibroplastica mit Bluteosinophilic. Schweiz Me Wochenschr. 1936;66:817. 89. Tanino M, Kitamura K, Ohta G, et al. Hypereosinophilic syndrome with extensive myocardial involvement and mitral valve thrombus instead of mural thrombi. Acta Pathol Jpn. 1983;33(6):1233–42. 90. Ommen SR, Seward JB, Tajik AJ. Clinical and echocardiographic features of hypereosinophilic syndromes. Am J Cardiol. 2000;86(1):110–13. 91. Feigenbaum H, Armstrong WF, Ryan T. Feigenbaum’s Echocardiography. 6th ed. Philadelphia: Lippincott, Williams & Wilkins; 2005:752. 92. Shah R, Ananthasubramaniam K. Evaluation of cardiac involvement in hypereosinophilic syndrome: complementary roles of transthoracic, transesophageal, and contrast echocardiography. Echocardiography. 2006; 23(8):689–91. 93. Yacoub S, Kotit S, Mocumbi AO, et al. Neglected diseases in cardiology: a call for urgent action. Nat Clin Pract Cardiovasc Med. 2008;5(4):176–7. 94. Rashwan MA, Ayman M, Ashour S, et al. Endomyocardial fibrosis in Egypt: an illustrated review. Br Heart J. 1995;73(3):284–9. 95. Mocumbi AO, Ferreira MB, Sidi D, et al. A population study of endomyocardial fibrosis in a rural area of Mozambique. N Engl J Med. 2008;359(1):43–9. 96. Acquatella H, Schiller NB. Echocardiographic recognition of Chagas’ disease and endomyocardial fibrosis. J Am Soc Echocardiogr. 1988;1(1):60–8. 97. Acquatella H, Schiller NB, Puigbó JJ, et al. Value of twodimensional echocardiography in endomyocardial disease with and without eosinophilia. A clinical and pathologic study. Circulation. 1983;67(6):1219–26. 98. Vignaux O. Cardiac sarcoidosis: spectrum of MRI features. AJR Am J Roentgenol. 2005;184(1):249–54. 99. Uemura A, Morimoto S, Kato Y, et al. Relationship between basal thinning of the interventricular septum and atrioventricular block in patients with cardiac sarcoidosis. Sarcoidosis Vasc Diffuse Lung Dis. 2005;22(1):63–5. 100. Matsumori A, Hara M, Nagai S, et al. Hypertrophic cardiomyopathy as a manifestation of cardiac sarcoidosis. Jpn Circ J. 2000;64(9):679–83. 101. Fahy GJ, Marwick T, McCreery CJ, et al. Doppler echocardiographic detection of left ventricular diastolic dysfunction in patients with pulmonary sarcoidosis. Chest. 1996;109(1):62–6.

102. Seward JB, Casaclang-Verzosa G. Infiltrative cardiovascular diseases: cardiomyopathies that look alike. J Am Coll Cardiol. 2010;55(17):1769–79. 103. Ptaszek LM, Price ET, Hu MY, et al. Early diagnosis of hemochromatosis-related cardiomyopathy with magnetic resonance imaging. J Cardiovasc Magn Reson. 2005;7(4):689–92. 104. Vieillard-Baron A. Septic cardiomyopathy. Ann Intensive Care. 2011;1(1):6. 105. Blanchard DG, Hagenhoff C, Chow LC, et al. Reversibility of cardiac abnormalities in human immunodeficiency virus (HIV)-infected individuals: a serial echocardiographic study. J Am Coll Cardiol. 1991;17(6):1270–6. 106. Velasquez EM, Glancy DL, Helmcke F, et al. Echocardiographic findings in HIV Disease and AIDS. Echocardiography. 2005;22(10):861–6. 107. Rerkpattanapipat P, Wongpraparut N, Jacobs LE, et al. Cardiac manifestations of acquired immunodeficiency syndrome. Arch Intern Med. 2000;160(5):602–608. 108. d’Amati G, di Gioia CR, Gallo P. Pathological findings of HIV-associated cardiovascular disease. Ann N Y Acad Sci. 2001;946:23–45. 109. Gilbert-Barness E. Review: Metabolic cardiomyopathy and conduction system defects in children. Ann Clin Lab Sci. 2004;34(1):15–34. 110. Francis GS. Diabetic cardiomyopathy: fact or fiction? Heart. 2001;85(3):247–8. 111. Picano E. Diabetic cardiomyopathy. the importance of being earliest. J Am Coll Cardiol. 2003;42(3):454–7. 112. Kannel WB, Hjortland M, Castelli WP. Role of diabetes in congestive heart failure: the Framingham study. Am J Cardiol. 1974;34(1):29–34. 113. Kitzman DW, Gardin JM, Gottdiener JS, et al. Cardiovascular Health Study Research Group. Importance of heart failure with preserved systolic function in patients > or = 65 years of age. CHS Research Group. Cardiovascular Health Study. Am J Cardiol. 2001;87(4):413–19. 114. Fang ZY, Yuda S, Anderson V, et al. Echocardiographic detection of early diabetic myocardial disease. J Am Coll Cardiol. 2003;41(4):611–17. 115. Modlin IM, Sandor A. An analysis of 8305 cases of carcinoid tumors. Cancer. 1997;79(4):813–29. 116. Kulke MH, Mayer RJ. Carcinoid tumors. N Engl J Med. 1999;340(11):858–68. 117. Lundin L, Norheim I, Landelius J, et al. Carcinoid heart disease: relationship of circulating vasoactive substances to ultrasound-detectable cardiac abnormalities. Circulation. 1988;77(2):264–9. 118. Thorson A, Biorck G, Bjorkman G, et al. Malignant carcinoid of the small intestine with metastases to the liver, valvular disease of the right side of the heart (pulmonary stenosis and tricuspid regurgitation without septal defects), peripheral vasomotor symptoms, bronchoconstriction, and an unusual type of cyanosis; a clinical and pathologic syndrome. Am Heart J. 1954;47(5):795–817.


119. Callahan JA, Wroblewski EM, Reeder GS, et al. Echocardiographic features of carcinoid heart disease. Am J Cardiol. 1982;50(4):762–8. 120. Howard RJ, Drobac M, Rider WD, et al. Carcinoid heart disease: diagnosis by two-dimensional echocardiography. Circulation. 1982;66(5):1059–65. 121. Roberts WC. A unique heart disease associated with a unique cancer: carcinoid heart disease. Am J Cardiol. 1997;80(2):251–6. 122. Pellikka PA, Tajik AJ, Khandheria BK, et al. Carcinoid heart disease. Clinical and echocardiographic spectrum in 74 patients. Circulation. 1993;87(4):1188–96. 123. Ross EM, Roberts WC. The carcinoid syndrome: comparison of 21 necropsy subjects with carcinoid heart disease to 15 necropsy subjects without carcinoid heart disease. Am J Med. 1985;79(3):339–54. 124. Moertel CG. Treatment of the carcinoid tumor and the malignant carcinoid syndrome. J Clin Oncol. 1983;1(11):727–40.

1417

125. Connolly HM, Schaff HV, Mullany CJ, et al. Surgical management of left-sided carcinoid heart disease. Circulation. 2001;104(12 Suppl 1):I36–I40. 126. Bhattacharyya S, Toumpanakis C, Burke M, et al. Features of carcinoid heart disease identified by 2- and 3-dimensional echocardiography and cardiac MRI. Circ Cardiovasc Imaging. 2010;3(1):103–11. 127. Bernheim AM, Connolly HM, Hobday TJ, et al. Carcinoid heart disease. Prog Cardiovasc Dis. 2007;49(6):439–51. 128. Dumaswala B, Bicer EI, Dumaswala K, et al. Live/Real time three-dimensional transthoracic echocardiographic assessment of the involvement of cardiac valves and chambers in carcinoid disease. Echocardiography. 2012; 29(6):751–6. 129. Khanna D, Miller AP, Nanda NC, et al. Transthoracic and transesophageal echocardiographic assessment of mitral regurgitation severity: usefulness of qualitative and semiquantitative techniques. Echocardiography. 2005; 22(9):748–69.

CHAPTER 67 Echocardiographic Differentiation of Ischemic and Nonischemic Cardiomyopathy: Comparison with Other Noninvasive Modalities Sula Mazimba, Arshad Kamel, Navin C Nanda, Maximiliano German Amado Escanuela, Kunal Bhagatwala, Nidhi M Karia

Snapshot ¾¾ Echocardiographic Assessment of Ischemic and

¾¾ Echocardiographic Distinction between Ischemic

Nonischemic Cardiomyopathy ¾¾ M-Mode Echocardiography ¾¾ Two-Dimensional/Three-Dimensional/Doppler Echocardiography

Cardiomyopathy and Nonischemic Dilated Cardiomyopathy ¾¾ Other Noninvasive Imaging Modalities

INTRODUCTION The left ventricle (LV) may be enlarged and show dysfunction in both ischemic heart disease and dilated cardiomyopathy. It is therefore important to distinguish ischemic cardiomyopathy (ICM) from nonischemic dilated cardiomyopathy (NICM) as management may be different. The distinction between the two types of conditions may have therapeutic and prognostic implications. Patients with ICM may benefit from a revascularization treatment strategy.1–3 Furthermore, patients with ICM have worse prognosis than NICM patients.4 In clinical practice, distinguishing between the two types of conditions can be very challenging. In some situations, a diagnosis can be inferred from history and physical examination (e.g. postpartum or chemotherapy-induced NICM). In general, distinction of the two cardiomyopathies lies in

the identification of significant coronary artery disease (CAD) as the primary mechanism for the LV dysfunction (< 45%). Definition of ICM requires the identification of significant CAD in the presence of depressed LV ejection fraction (EF). Significant CAD for the ICM has been proposed as stenosis of any of the epicardial vessels > 75%, or a history of myocardial infarction or previous revascularization of the coronaries.5 Coronary angiography remains the gold standard method of evaluating CAD.5–9 Nonetheless, coronary angiography is not without risks. It is invasive, operator-dependent, and may be associated with adverse events.9,10 A noninvasive imaging modality, particularly in patients with low to intermediate pretest probability for CAD is often recommended. Coronary angiography is reserved for patients with a high pretest probability for CAD, who may also benefit from revascul arization.9

Chapter 67: Echocardiographic Differentiation of Ischemic and Nonischemic Cardiomyopathy

1419

Fig. 67.1: Parasternal long-axis view showing a severely dilated left ventricular cavity. There is malcoaptation of the anterior and posterior mitral valve leaflets. (AO: Ascending aorta; DA: Descending aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 67.2: Nonischemic cardiomyopathy. M-mode echocardiography shows a large mitral–septal separation, E-point septal separation (EPSS) of 45 mm is noted on the M-mode. (AO: Aorta; LA: Left atrium; LV: Left ventricle).

ECHOCARDIOGRAPHIC ASSESSMENT OF ISCHEMIC AND NONISCHEMIC CARDIOMYOPATHY

LV systolic function is strongly related to functional status and prognosis in patients with cardio myopathy.22 The predictive impact of LVEF on mortality is much more pronounced in ICM than NICM.23 Doppler measures of contractility are reduced in both ICM and NICM. The left ventricular outflow tract flow velocity or velocity time integral is usually decreased to <18 cm. Another measure of ventricular contractility is the dP/dt (i.e. the change in left ventricular pressure over time). This is measured from the mitral regurgitant jet. A value of <600 indicates significant impairment of the LV contractility. A low dP/dt is associated with adverse cardiovascular outcomes and mortality.24,25 The myo cardial performance index (MPI), or the Tei index is another Doppler-derived measure of systolic and diastolic ventricular function.26 A calculated MPI value of > 0.60 is correlated with adverse outcomes in both patients with nonischemic and ischemic cardiomyopathies.27–29

Two-dimensional (2D) echocardiography is a low-cost and widely available diagnostic tool used in the initial evaluation of patients with left ventricular systolic dysfunction.11 Left ventricular dilatation has been implicated in the initial development and progression of systolic dysfunction with or without CAD (Figs 67.1 to 67.3. Also Figs 66.1C and 66.2B in Chapter 66)12–14 it is thought that ventricular dilatation is the initial adaptive response of a failing heart.15,16 As the LV chamber further enlarges, a remodeling process that is regulated by mechanical, neurohormonal, and genetic factors ensue.12,17–19 The end result is a change in the geometric configuration of the heart muscle from an ellipsoid to a spherical shape.20 A spherically shaped heart has ineffectual muscle contractions, larger ventricular volumes, and conformational changes in the mitral annular apparatus. NICM on echo is characterized by an increase in ventricular chamber sizes with reduced indices of systolic function (left ventricular ejection fraction [LVEF] < 45%, or fractional shortening < 25% and reduced fractional area change). The enlarged LV chambers occur in the setting of normal or reduced LV thickness.21 Systolic function is often reduced in dilated cardio myopathy (Fig. 67.1). The degree of reduction of the LVEF is well correlated to the severity of the cardiomyopathy.4

M-MODE ECHOCARDIOGRAPHY The sphericity index (SI) is a surrogate marker of LV remodeling. It is the ratio of left ventricular long-axis internal dimension to the LV diameter at end-systole.30,31 A SI of <1.5 underscores a very severely dilated LV cavity. Another M-mode parameter, which is related to LV cavity dilatation and reduced LV systolic excursion, is the E-point septal separation (EPSS). This is measured as the distance from the tip of the open anterior mitral leaflet in diastole

1420


A

B

C

D

E

F

Figs 67.3A to F


1421

Figs 67.3A to G: Ischemic cardiomyopathy in a 38-year-old female patient. M-mode/two-dimensional transthoracic echocardiography. (A and B) Parasternal long-axis views demonstrating a huge left ventricle (LV) measuring 90 mm and severe mitral regurgitation (arrow); (C and D) M-mode examination showing a very large LV with severely reduced function. Also note markedly increased E-point septal separation (EPSS) measuring 32 mm in D; (E to G) Apical views; (E) The coaptation point of the mitral leaflets is displaced into the LV and directed eccentrically toward the LV free wall, suggesting ischemic origin of cardiomyopathy; (F) Shows dyskinesis (arrow) of the distal LV inferior wall and septum; (G) Severe mitral regurgitation (arrow) resulting from reduced coaptation of the displaced mitral leaflets. Movie clip H shows hypokinesis (arrow) of the distal right ventricular (RV) free wall. (AO: Aorta; LA: Left atrium; RA: Right atrium) (Movie clips 67.3A to 67.3H).

G

to the ventricular septal wall. A normal value is < 6 mm.32 EPSS of >10 mm reflects severe LV dilatation and systolic dysfunction (Fig. 67.2).32–34 The utility of EPSS is limited in aortic regurgitation and mitral stenosis. The aortic valve may demonstrate reduced leaflet excursions coupled with early closure. Both these features are a reflection of a diminished cardiac output. Another feature on M-mode that signifies low cardiac output is the reduced wall motion of the aortic root. One of the advantages of M-Mode echo is its high temporal resolution (1000– 3000 Hz compared to 20–129 Hz with 2D echo). Twodimensional echocardiography, on the other hand, has a higher spatial resolution compared to M-mode. Thus, combining the two modalities can be helpful in guiding accurate alignment of the M-mode beam for reliable quantification of the chamber sizes.35 Severe NICM is suggested by left ventricular end-diastolic dimension > 56 mm in males and 53 mm in females. A dilated LV chamber in the setting of normal or reduced LV wall thickness (end-diastolic wall thickness of <6 mm) that is global in nature is highly indicative of NICM. In ICM, there may be regional variation in thickness of the myocardium. Myocardial thickness of <6 mm at end diastole is highly suggestive of nonviable myocardium.36

TWO-DIMENSIONAL/THREEDIMENSIONAL/DOPPLER ECHOCARDIOGRAPHY

(DCM). Even though linearly derived measurements are used to calculate chamber sizes, these measurements are based on geometric assumptions of the LV cavity in the form of a truncated ellipsoid.21 These measurements, however, may grossly underestimate the true LV sizes and volumes in CAD patients with distorted LV cavities. This is because of the regional wall motion abnormalities (WMAs) often present in CAD (presence of aneurysms, WMAs, asymmetrical and foreshortened ventricles). Therefore, volumetric measurements for accurate cardiac chamber size quantification are preferred to linear measurements. More recently, three-dimensional (3D) echo has been shown to have an advantage over 2D echoderived measurements. Three-dimensional transthoracic echocardiography (3D TTE) can overcome the limitation of quantifying volumes in ICM patients with distorted LVs. Volumetric measurements by 3D echo yield more accurate and reproducible measurements [comparable to radionuclide or cardiac magnetic resonance imaging (CMR)].37–40 One of the challenges of obtaining volumetric measurements in 3D echo arises when the cardiac chambers are foreshortened. This situation can lead to an underestimation of LV volumes.41 Automated endocardial tracings have been recommended as one way of overcoming this limitation.42 In the difficult situation with poor endocardial visualization, the use of contrast agents can enhance the accuracy and reproducibility of measurements.43

Left Ventricular Volumes

Left Ventricular End-Systolic Volume Index

Correct quantification of the cardiac chambers is necessary in assessing the severity of the dilated cardiomyopathy

End-systolic volume index (ESVI) provides important information regarding the severity and prognosis of

1422


NICM.44–46 ESVI increases progressively with the advan cement of disease. It has been shown conclusively that adverse outcomes increase with an ESVI of > 25 mL/m2 (normal value, < 20 mL/m2).45 An ESVI > 60 mL/m2 is associated with increased adverse outcomes in patients with ICM undergoing surgical ventricular reconstruction.47

Two-dimensional Echo/Doppler-Derived Left Ventricular Diastolic Dysfunction Diastolic function assessment in NICM and ICM provides useful information regarding the severity and overall prognosis. Patients with restrictive diastolic physiology on two-dimensional transthoracic echocardio graphy 48,49 (2D TTE) have increased adverse outcomes. A short deceleration E time is associated with severe symptoms and is also a powerful and independent prognostic indicator of poor outcomes in patients with NICM.22,49– 51 Grade II diastolic dysfunction has also been shown to predict adverse outcomes and increased hospital re-admissions in patients with NICM.52

Right Ventricle Right ventricular (RV) dysfunction is a powerful predictor for exercise capacity as well as mortality in patients with NICM.53–55 Assessment of RV function is often challenging because of the complexity of the 3D structure that is less amenable to geometric assumptions like the LV. In addition, the RV is in a substernal position, which renders imaging more challenging. The numerous trabeculations also renders volumetric assessment of the RV function challenging.56,57 3D TTE, however, compares favorably with CMR in the assessment of RV function.58 A 2D TTE parameter that has been validated in the assessment of RV function is the tricuspid annular plane systolic excursion (TAPSE).59,60 Right ventricular function is measured by the degree of excursion of the tricuspid annulus from the base to the apex. A TAPSE of <15 mm is associated with poor RV systolic function. Decreased RV systolic function as estimated by TAPSE is associated with increased mortality in patients admitted for heart failure. Among patients with LV systolic dysfunction, the involvement of RV dilatation is often suggestive of a NICM. The RV is often spared in ICM unless there is accompanying right ventricular infarction in which case the right ventricle will be affected. RV involvement portends worse adverse outcomes in both NICM and ICM.55,61–63

Left Atrium Left atrial (LA) size has been shown to have prognostic value in patients with NICM. LA volume is determined by the degree of LV dilatation, diastolic dysfunction as well as the severity of mitral regurgitation (MR).64,65 LA size correlates well with the severity of diastolic dysfunction, which in turn has prognostic information for patients with both ICM and NICM.66–72 In patients with NICM with functional MR, LA size may reflect the duration of the MR.73 The LA size was a more powerful predictive variable than the severity of MR jet in determining adverse outcomes in NICM patients.65 The current American Society of Echocardiography guidelines recommends obtaining LA volumes rather than linear dimensions, which do not take into account the asymmetric remodeling of the chamber.21,74,75 The upper limit of normal LA-ESVI is 28 mL/m2.21

Mitral Regurgitation: Mechanisms Functional MR is a common feature in patients with NICM or ICM. The presence of MR is associated with poor prognosis even in patients with prior repair of the mitral valve (MV).76–79 Functional MR is characterized by malcoaptation of the two mitral leaflets despite a structurally normal MV (Figs 67.3B, 67.3G and 67.4). In an occasional patient with ICM, the “seagull” sign may be visualized as explained in Figure 67.4.80 The mechanism related to the malcoaptation of the leaflets is thought to be due to the remodeling of the LV cavity.81–83 Factors thought to contribute to MR include dilatation of the mitral annulus, tethering of the leaflets (due to apical or posterior displacement of the papillary muscles), and reduced LV function (geometric changes occurring in a remodeled ventricle).84–94 The degree of conformational changes that occur in the MV apparatus in functional MR can be quantitatively assessed. These geometric variables for MV deformation are discussed in the following section.

Tenting Area This is the area enclosed by the annular plane and the two mitral leaflets (Fig. 67.5). It has been shown to accurately reflect the degree of functional mitral regurgitation (FMR). It is also an independent predictor of mortality and hospitalization in patients with NICM.95 Patients with a tenting area > 3.4 cm2 had higher brain naturetic peptide (BNP) levels, worse functional status, more hospitalizations, and higher death rates.


1423

Fig. 67.5: The shaded region illustrates the tenting area of the mitral valve. (H: Tenting height; LA: Left atrium; LV: Left ventricle; MV: Mitral valve). Fig. 67.4: Transesophageal apical four-chamber view showing severe mitral regurgitation by color Doppler flow imaging (arrow). Arrowhead shows a kink in the middle of the anterior leaflet mimicking a “seagull.” This “seagull” sign results from tethering produced by a strut chord and is considered indicative of ischemic origin of cardiomyopathy. (LA: Left atrium; LV: Left ventricle; RV: Right ventricle) (Movie clip 67.4).

Fig. 67.6: A section of mitral valve from apical four-chamber view. 1 = anterior leaflet angle (ALα) which measured 21°. 2 = posterior leaflet angle (PLα) which measured 62° (LA: Left atrium; LV: Left ventricle).

Coaptation depth, otherwise known as MV tenting height, is the shortest distance between the leaflet coap tation point and the mitral annular plane (Fig. 67.5).96 The degree of leaflet tethering is measured by the angle at which each of the two mitral leaflets joins the mitral annular plane. These are the anterior leaflet angle (ALa) and the posterior leaflet angle (PLa; Fig. 67.6). Because there is differential insertion of fibers on the mitral leaflets (fine marginal chordae fibers insert at the leaflet tips and the thicker chordae insert at the leaflet base), further categorization of the AL angles can be made. Tethering of the anterior MV leaflet at the base (ALa base) is measured by obtaining the angle at AL base as it intersects with the

annular plane. On the other hand, tethering at the distal AL tip (ALa tip) is calculated by measuring the angle between the annular plane and a line that joins the anterior annulus and the coaptation point of the two leaflets.94,97 Lee et al. have proposed a classification of AL tethering into three subtypes based on the morphology and site of maximal AL tenting.97 Type I AL: Tethering involves minimally tethered AL along its long-axis dimension. Type II AL: Tethering is characterized by posteriorly directed tethering by the basal chordae. The morphology of AL has a very prominent bend on 2D echo imaging. Type III AL: Consists of a pronounced apical tethering of both the base and the distal tip of the AL. It is often recognized on echo by a large AL tip angle. It has been proposed that this classification should help guide treatment decisions in patients with functional MR. For instance, mitral annuloplasty is more likely to be successful with type I and II subtypes.97 Both the PLa and ALa have been shown to offer diagnostic and prognostic information in patients with ischemic MR.98–101 One of the distinguishing features of ICM from NICM is in the pattern of MV deformation (measured as a change in the AL and PL angles). The MV deformation is geometrically asymmetrical in ICM compared to NICM.101,102 In the NICM, the conformational changes of the MV are the same in all the planes. It appears that regional LV remodeling from ischemia results in asymmetrical papillary muscle displacement, which then leads to asymmetrical leaflet tethering, thereby affecting the coaptation of the two mitral leaflets. Two separate regurgitant jets often characterize ICM MR.101,103,104 These

1424


jets correspond to the deformational changes in the MV leaflets. There is a funnel-shaped conformational deformity in the medial side of the MV and a prolapsed deformity in the lateral portion of the valve. The medial deformity is responsible for the centrally directed jet, while the lateral prolapsed deformity is responsible for the eccentric jet. Interestingly, it is the asymmetrical apically oriented displacement of the papillary muscles rather than the asymmetrical medial lateral orientation of the papillary muscle displacement that accounts for the MV deformational changes seen in ICM.102 The coaptation depth and tenting area both correlate with the severity of MR in patients with systolic dysfu nction.93 Furthermore, these parameters have been shown to confer prognostic information in patients undergoing functional MV intervention. Magne et al noted that in ICM patients undergoing functional MV annuloplasty, the presence of a PLa of more than 45° had increased rates of recurrent MR and other adverse events.100 There is a growing body of evidence to suggest that the geometric differences in the patterns of tethering seen in ICM and NICM can help guide the choice of therapy for functional MR.92,97,101,105

Stress Echocardiography Stress echocardiography has emerged as a useful tool for the evaluation of selected patients with suspected or known ischemic heart disease.106 The high specificity of stress echocardiography compared to other modalities contributes to its utility as a cost-effective diagnostic tool for CAD. The sensitivity and specificity of new WMAs induced by dobutamine for detection of CAD is 89% and 85%, respectively. The sensitivity in those with multivessel or left main disease is 100% compared to 81% in those with a single vessel disease.107 Dobutamine stress echo can help differentiate between ICM and NICM. In the absence of CAD, the normal response to dobutamine stress test is augmentation of systolic function and contractility with increasing doses of dobutamine. In the presence of significant disease, an initial augmentation of LVEF and contractility is followed by a decline in LVEF and/or contractility or emergence of new WMA at higher doses of dobutamine.106,108 The segmental wall motions are graded by dividing the heart into 16 segments (17 segments if echo is being compared with another imaging modality such as nuclear perfusion) and each segment is then graded on a scale of 1–4 on the basis of wall motion (1 = normal, 2 = hypokinesis, 3 = akinesis, 4 = dyskinesis).109 A cumulative score is obtained at

baseline and at end of the study. A cumulative score of all the segments is then divided by the number of segments. A numerical score of 1 is normal while that above 1 is abnormal. Higher scores predict higher severity of obstructive disease or the presence of more extensive disease. Dobutamine stress echo can also help identify patients with ICM that can benefit from revascularization. Patients who have an initial augmentation of LVEF and contractility at low dose dobutamine followed by a decline with high dose (biphasic response) are candidates for revascularization. A biphasic response indicates viable myocardium that could be salvaged with revascularization.

Coronary Echocardiography 2D TTE has been studied as a means of detecting CAD and by extension, potentially differentiating ICM from NICM.110 2D TTE was able to detect proximal CAD in 93% of the study patients. Interestingly, visualization of the coronaries in dilated LV was much easier in patients with NICM than ICM. This is primarily because NICM patients generally have much larger chamber sizes than ICM patients and, therefore, the curvature of the coronary arteries is less steep and easily visualized. Although the success rate of visualizing CAD lesions using 2D TTE was high in this study, other researchers have recorded much lower success rates.111–113

Myocardial Contrast Echocardiography There is an emerging role of myocardial contrast echocar diography (MCE) in assessing myocardial perfusion status in patients suspected of having CAD.114–117 MCE uses contrast agents to improve the visualization of blood– endocardial interface. This enables the assessment of ventricular wall motion, wall thickness, LVEF, and qualitative and quantitative evaluation of myocardial and coronary blood flow.43 One of the advantages of MCE is that it not only provides microcirculatory blood flow information, but also transmural blood flow information. Using a vasodilator pharmacological stress test, myocardial perfusion may be assessed both at rest and stress. With this information, myocardial blood flow reserve is measured as the difference between the peak flow during stress and baseline flow at rest. Endomyocardial flow impairment has been shown to be directly associated with the progression of LV dysfunction. 7,118 The application of MCE in clinical practice is still limited and remains to be standardized.


ECHOCARDIOGRAPHIC DISTINCTION BETWEEN ISCHEMIC CARDIOMYOPATHY AND NONISCHEMIC DILATED CARDIOMYOPATHY There are several features on 2D TTE that help distinguish ICM from dilated NICM (Table 67.1). Traditionally, WMAs have been used to discriminate between NICM and ICM. In ICM, the WMA tend to be regional and correspond to specific coronary artery distribution.119,120 The presence of WMA has more diagnostic value in normal sized ventricles.121–125 Medina et al.121 studied 60 patients with dilated LV and LV dysfunction using 2D TTE for the detection of regional WMA so as to differentiate between ICM and NICM. They reported a sensitivity, specificity, and predictive accuracy of 83%, 57%, and 77%, respectively, in differentiating ICM from NICM based on the presence of WMA. In patients with normal LV size but LV dysfunction, the sensitivity, specificity, and predictive accuracy were found to be 95%, 100%, and 95%, respectively, in detecting ICM.120 Besides WMA, identification of regional thinning of myocardial wall (< 6 mm), or aneurysmal myocardial segment corresponding to coronary blood flow area increases the likelihood of the diagnosis of ICM. Aneurysms and scar on the LV surface were found in fewer than 15% of NICM on necropsies conducted by Roberts et al.126 Chen et al. used semiquantitative echocardiographic segmental wall motion scoring to predict CAD. Myocardial wall motion was scored according to the scoring described by Heger et al.127 (i.e. hyperkinesia = −1, normal = 0, hypoki nesia = 1, akinesia = 2, and dyskinesis = 3). Patients with a LVEF < 50% had a mean score of 6.9, while those with LVEF above 50% had a mean score of 1.1.122 The above criteria are, however, not entirely exhaustive in defining ICM because WMA may also be seen in up to two-thirds of patients with NICM.107,128–130 These WMA in patients with NICM have been attributed to abnormal microcirculatory perfusion despite normal epicardial blood vessels.131,132 Wallis et al. showed that up to 64% of patient with NICM had WMAs especially when conduction abnormalities were present (i.e. left bundle branch block [LBBB]). When they excluded patients with LBBB, WMA were found in 59% of the study population with NICM.128 In the same study, Wallis et al. found that WMA were more commonly associated with older age. The younger patients with NICM had more diffuse involvement, were more symptomatic, and generally had a poor prognosis. Because resting WMA is not sensitive at discriminating CAD, the

1425

situation is made worse if there is a concomitant LBBB. Duncan et al used quantified stress echocardiography to assess changes in the long-axis systolic amplitude to discriminate between ICM and NICM. In the presence of LBBB, inability to increase septal systolic amplitude by >1.5 mm was highly indicative of CAD. This method was better than visual assessment of wall motion score index (WMSI; sensitivity and specificity of 94% and 100%, respectively).133 RV dilatation can be suggestive of NICM. The right ventricle is often spared in ICM unless, as mentioned previously, there is accompanying RV infarction in which case one would expect to see a hypocontractile, dilated RV.62,63 Involvement of the RV is indicative of an advanced disease stage and is a poor prognostic sign in either ICM or NICM.134 Because of the complex 3D structure, quantification of the RV is rendered difficult with 2D TTE, but can be assessed more accurately with 3D TTE.135

OTHER NONINVASIVE IMAGING MODALITIES Single-Photon Emission Computed Tomography Myocardial perfusion imaging (MPI) using singlephoton emission computed tomography (SPECT) is a well-validated, noninvasive imaging modality used in the diagnosis, treatment and prognostication of CAD.136–139 SPECT MPI has high sensitivity and specificity that approaches 90% in detecting significant CAD (with at least 50% luminal diameter stenosis).140–142 In broad terms, SPECT MPI classifies patients in three categories— normal study (normal perfusion defects at stress and rest), reversible ischemia (perfusion defects with stress and normal perfusion at rest), and a fixed scar (perfusion abnormality at rest and stress). It is known that on SPECT MPI, NICM is characterized by homogenous tracer uptake, whereas ICM has extensive perfusion defects that are often regional.138,143–145 Patients with reversible perfusion defects usually benefit from revascularization treatment strategies. The limitation of SPECT with thallium is that patients with NICM can still present with perfusion defects even in the absence of significant CAD.146 The combination of perfusion abnormalities that occur in myocardial territories consistent with areas of WMA overcomes the problem of WMA alone in NICM undergoing thallium imaging alone.147 Large perfusion defects, however, are more predictive of significant ICM

1426


Table 67.1: Comparison of Noninvasive Findings in Ischemic Cardiomyopathy and Nonischemic Dilated Cardiomyopathy

Modality

ICM with Dilated LV

NICM with Dilated LV

Clinical evaluation

• Older patients

• May be younger

• H istory of ischemic heart disease such as angina and myocardial infarction

• May not have history of ischemic heart disease

• S egmental WMA/thinning (<6 mm in end diastole) in coronary artery distribution. Sensitivity 65% to 81%, and specificity 56% to 99%

• Less common. Defects when present may not relate to coronary artery distribution

• E ndocardial brightening/scarring more common due to infarction

• Less common

• B iphasic response with dobutamine stress test indicative of hibernating viable myocardium is more common

• Less common

• P erfusion defects with contrast echo more common

• Less common

• 2 D TTE/Doppler may show stenosis in proximal or other coronary arteries, which may be small

• Coronary arteries may show no stenosis, may be larger

• Spherical LV less common

• Spherical LV more common

• M ay show prominent plaques in larger vessels such as ascending aorta, arch, and abdominal aorta.

• May be normal

• A symmetric closure of mitral valve leaflets with eccentric regurgitation jet(s) more common. “Seagull” sign (Fig. 67.4) may be present

• Symmetric closure with central jets more common. “Seagull” sign absent

• LV dilatation less severe

• Severe spherical LV dilatation with malcoaptation of mitral valve leaflets

• R ight ventricle usually not enlarged and function normal except when RCA is stenotic/occluded or RV infarction present

• RV enlargement and/or dysfunction more frequent

Single-photon emission computed tomography (SPECT)

• P erfusion defects in coronary artery distribution. More accurate if combined with WMA • Normal sized RV with good function more common

• Perfusion defects less common and if present do not relate to coronary artery distribution • Large RV with reduced function more common

Coronary computed tomographic angiogram (CCTA)

• C oronary artery calcification more common.Coronary stenosis, both obstructive and nonobstructive may be identified

• Less common

Cardiac magnetic resonance (CMR)

• I ncreased gadolinium uptake or enhancement indicating scar formation in the previously infarcted areas more common • Regional WMA/thinning and perfusion defects similar to echocardiography above

• Less common

• Large mismatch defects more common

• Less common

Echocardiography

Positron emission tomography (PET)

• May have history of viral infections, septicemia, alcoholism, metabolic, or infiltrative diseases

• Regional WMA/thinning and perfusion defects similar to echocardiography above

(2D TTE: Two-dimensional transthoracic echocardiography; ICM: Ischemic cardiomyopathy; LV: Left ventricle; NICM: Nonischemic cardiomyopathy; RV: Right ventricle; WMAs: Wall motion abnormalities).


than smaller defects. When a large perfusion defect is present, the sensitivity of SPECT to accurately identify ICM was as high as 97%. Conversely, in the absence of a large perfusion defect, SPECT MPI was able to accurately discriminate NICM in 94% of the study group.144 More recently, an approach that incorporates the severity of the defect with the extent of WMA was shown to increase the likelihood of detecting ICM. Defect severity ratio was computed by measuring the ratio of the count density of the most severe perfusion defect over the count density of the most normal area of myocardium. A stress defect ratio < 45% was predictive of ICM (with a sensitivity of 60% and specificity of 91%). Most patients with NICM had higher stress defect ratio.148 Electrocardiographically gated radionuclide ventriculography (RNV) has been shown to have incremental value in differentiating between NICM and ICM. Given that WMA are not confined to ICM, the EF information provided by RNV can further serve as a pointer to the diagnosis. NICM patients have lower LVEF, which often involves the RV as well.149

Coronary Computed Tomographic Angiogram Coronary computed tomographic angiogram (CCTA) has emerged to be an important noninvasive diagnostic modality in the evaluation of CAD.150–152 The diagnostic utility of CCTA is in patients with low to intermediate risk for CAD. There are several published studies that have looked at the role of CCTA in differentiating between NICM and ICM.153–157 Two primary avenues by which CCTA stratifies patients for the underlying CAD is the calculation of calcium score and by anatomical definition of coronary arteries for presence of a plaque or stenosis. Calcium score is calculated using electron-beam computed tomography (EBCT) and multislice computed tomography (MSCT). A high burden of coronary calcium (calcium score of > 80) assessed by EBCT was associated with a 99% sensitivity and an 83% specificity in accurately identifying patients with ICM.154 Presence of calcium is a known marker for atherosclerosis. In another imaging modality using ultrasound of the carotids, carotid calcification in patients with dilated cardiomyopathy had a sensitivity of 96% and specificity of 89% of accurately identifying ICM.158 CCTA is more sensitive in identifying patients with ICM than 2D TTE (sensitivity of 68% and specificity of 73%).159,160 However, the sensitivity of CCTA to accurately diagnose ICM decreases in patients with a high calcium burden (to 73%).156

1427

Cardiac Magnetic Resonance Imaging CMR has become an important noninvasive diagnostic tool in the evaluation of various cardiac conditions.161 It has become the reference, if not the gold standard, for evaluation of cardiac chamber sizes, mass, volumetric measurements, and EF. In clinical situations that require serial cardiac measurements, CMR has an added advantage of being highly reproducible with low interand intra-study variability. Other advantages of CMR include absence of ionizing radiation and relatively high spatial and temporal resolution.161,162 The clinical applications of CMR continue to evolve and expand, and now include noninvasive evaluation of the proximal coronaries.163,164 The sensitivity and specificity of CMR for the detection of CAD is 91% and 81%, respectively.165 CMR has been studied in the differentiation of ICM from NICM. Furthermore, the use of gadolinium enhancement helps with characterizing scar and other secondary causes of NICM (i.e. myocarditis, sarcoidosis).164,166,167 In patients with ICM, CMR identifies subendocardial or transmural enhancement indicative of scar formation in virtually 100% of the patients.167,168 In the NICM patients, three patterns are identified. The first pattern shows no enhancement with gadolinium, the second subset shows subendocardial/transmural enhancement similar to the ICM, and the third subset shows longitudinal patchy midwall enhancement. Enhancement with gadolinium highlights areas of the myocardium with previous infarction.169 The most common type of CMR pattern (58%) is no enhancement, a finding consistent with a clinical picture of no previous areas of infarction. The second subtype shows enhancement similar to that of ICM (13%) but without obstructive coronary lesions on angiography. These findings represent myocardial infarction from an embolic plaque or a coronary artery source that has recanalized. The third subtype (28%) involves patchy midwall enhancement that has been attributed to fibrosis of the midventricular wall. The pathogenesis of this type of fibrosis has been linked to a whole host of potential etiologies such as genetic factors, toxins, infections, microvascular ischemia, neurohormonal, and immunological factors.170–173 The pattern of enhancement of the scar has prognostic information. Improvement of contractility after revascularization is low in patients with extensive transmural extent of the scar; for instance, if there is >50% delayed enhancement on CMR, the likelihood of response to revascularization was <10%.164 More recently,

1428


Assomull et al. showed that in NICM patients with patchy midwall fibrosis on CMR, midwall fibrosis was a significant predictor of death or hospitalization. Midwall fibrosis also predicted secondary outcome measures of sudden cardiac death or ventricular tachycardia.171

Positron Emission Tomography Positron emission tomography (PET) imaging is an ideal noninvasive diagnostic tool for assessing myocardial viability. The advantage of PET is that, not only does it detail coronary artery blood flow, but it also provides valuable information on the metabolic activity of the myocardium.174,175 PET has the advantage of having higher temporal and spatial resolution than SPECT imaging. PET imaging has been shown to accurately predict ICM patients who would benefit from surgical revascularization after viability testing.176 The commonly used perfusion agents are ammonium-13 and rubidium 82, while a commonly used metabolic agent is F-18 FDG. Carbon-11 palmitate has also been used as a marker of metabolism (a marker of free fatty acid utilization).177 Ordinarily myocardial cells utilize free fatty acids for energy metabolism. Ischemic myocardial cells, on the other, hand utilize glucose instead of free fatty acids. Thus, with PET imaging, radiolabeled glucose (F-18 FDG) can be visualized when it is taken up by myocardial cells. Reduced perfusion and increased glucose uptakes indicate presence of ischemia with viable myocardium. On the other hand, reduced uptake of perfusion and metabolic agent indicates the presence of nonviable myocardium or scar tissue. ICM patients show large mismatched defects on PET imaging than NICM patients.177 The sensitivity and specificity of PET imaging for differentiating between ICM and NICM are 85% and 80%, respectively.174,177

REFERENCES 1. Alderman EL, Fisher LD, Litwin P, et al. Results of coronary artery surgery in patients with poor left ventricular function (CASS). Circulation. 1983;68(4):785–95. 2. Passamani E, Davis KB, Gillespie MJ, et al. A randomized trial of coronary artery bypass surgery. Survival of patients with a low ejection fraction. N Engl J Med. 1985;312(26): 1665–71. 3. Freeman AP, Walsh WF, Giles RW, et al. Early and longterm results of coronary artery bypass grafting with severely depressed left ventricular performance. Am J Cardiol. 1984;54(7):749–54. 4. Likoff MJ, Chandler SL, Kay HR. Clinical determinants of mortality in chronic congestive heart failure secondary to

idiopathic dilated or to ischemic cardiomyopathy. Am J Cardiol. 1987;59(6):634–8. 5. Felker GM, Shaw LK, O’Connor CM. A standardized definition of ischemic cardiomyopathy for use in clinical research. J Am Coll Cardiol. 2002;39(2):210–18. 6. Beanlands RS, Ruddy TD, deKemp RA, et al. PARR Investigators. Positron emission tomography and recovery following revascularization (PARR-1): the importance of scar and the development of a prediction rule for the degree of recovery of left ventricular function. J Am Coll Cardiol. 2002;40(10):1735–43. 7. Bart BA, Shaw LK, McCants CB Jr, et al. Clinical determ inants of mortality in patients with angiographically diag nosed ischemic or nonischemic cardiomyopathy. J Am Coll Cardiol. 1997;30(4):1002–8. 8. Elefteriades JA, Tolis G Jr, Levi E, et al. Coronary artery bypass grafting in severe left ventricular dysfunction: excellent survival with improved ejection fraction and functional state. J Am Coll Cardiol. 1993;22(5):1411–17. 9. Scanlon PJ, Faxon DP, Audet AM, et al. ACC/AHA guidelines for coronary angiography. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Coronary Angio graphy). Developed in collaboration with the Society for Cardiac Angiography and Interventions. J Am Coll Cardiol. 1999;33(6):1756–824. 10. Ammann P, Brunner-La Rocca HP, Angehrn W, et al. Procedural complications following diagnostic coronary angiography are related to the operator’s experience and the catheter size. Catheter Cardiovasc Interv. 2003;59(1): 13–18. 11. Nieminen MS, Böhm M, Cowie MR, et al. ESC Committe for Practice Guideline (CPG). Executive summary of the guidelines on the diagnosis and treatment of acute heart failure: the Task Force on Acute Heart Failure of the European Society of Cardiology. Eur Heart J. 2005;26(4):384–416. 12. Pfeffer MA, Braunwald E. Ventricular remodeling after myocardial infarction. Experimental observations and clinical implications. Circulation. 1990;81(4):1161–72. 13. Gaudron P, Eilles C, Kugler I, et al. Progressive left ventricular dysfunction and remodeling after myocardial infarction. Potential mechanisms and early predictors. Circulation. 1993;87(3):755–63. 14. Vasan RS, Larson MG, Benjamin EJ, et al. Left ventricular dilatation and the risk of congestive heart failure in people without myocardial infarction. N Engl J Med. 1997; 336(19):1350–5. 15. Cohn JN. Structural basis for heart failure. Ventricular remodeling and its pharmacological inhibition. Circulation. 1995;91(10):2504–7. 16. Gaudron P, Eilles C, Ertl G, et al. Compensatory and non compensatory left ventricular dilatation after myocardial infarction: time course and hemodynamic consequences at rest and during exercise. Am Heart J 1992; 123(2):377–85. 17. Rouleau JL, de Champlain J, Klein M, et al. Activation of neurohumoral systems in postinfarction left ventricular dysfunction. J Am Coll Cardiol. 1993;22(2):390–8.


18. Eaton LW, Weiss JL, Bulkley BH, et al. Regional cardiac dilatation after acute myocardial infarction: recognition by two-dimensional echocardiography. N Engl J Med. 1979; 300(2):57–62. 19. Opie LH, Commerford PJ, Gersh BJ, et al. Controversies in ventricular remodeling. Lancet. 2006; 367(9507): 356–67. 20. Simonson JS, Schiller NB. Descent of the base of the left ventricle: an echocardiographic index of left ventricular function. J Am Soc Echocardiogr. 1989;2(1):25–35. 21. Lang RM, Bierig M, Devereux RB, et al. Chamber Quantification Writing Group; American Society of Echocardiography’s Guidelines and Standards Committee; European Association of Echocardiography. Recomm endations for chamber quantification: a report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the Euro pean Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18(12):1440–63. 22. Rihal CS, Nishimura RA, Hatle LK, et al. Systolic and diastolic dysfunction in patients with clinical diagnosis of dilated cardiomyopathy. Relation to symptoms and prognosis. Circulation. 1994;90(6):2772–9. 23. Risk stratification and survival after myocardial infarction. N Engl J Med. 1983;309(6):331–6. 24. Loutfi H, Nishimura RA. Quantitative evaluation of left ventricular systolic function by Doppler echocardiographic techniques. Echocardiography. 1994;11(3):305–14. 25. Kolias TJ, Aaronson KD, Armstrong WF. Doppler-derived dP/dt and -dP/dt predict survival in congestive heart failure. J Am Coll Cardiol. 2000;36(5):1594–9. 26. Tei C, Ling LH, Hodge DO, et al. New index of combined systolic and diastolic myocardial performance: a simple and reproducible measure of cardiac function–a study in normals and dilated cardiomyopathy. J Cardiol. 1995; 26(6):357–66. 27. Bruch C, Schmermund A, Marin D, et al. Tei-index in patients with mild-to-moderate congestive heart failure. Eur Heart J. 2000;21(22):1888–95. 28. Dujardin KS, Tei C, Yeo TC, et al. Prognostic value of a Doppler index combining systolic and diastolic perfor mance in idiopathic-dilated cardiomyopathy. Am J Cardiol. 1998;82(9):1071–6. 29. Poulsen SH, Jensen SE, Tei C, et al. Value of the Doppler index of myocardial performance in the early phase of acute myocardial infarction. J Am Soc Echocardiogr. 2000;13(8):723–30. 30. Tischler MD, Ashikaga T, LeWinter MM. Relation between left ventricular shape and Doppler filling parameters in patients with left ventricular dysfunction secondary to coronary artery disease. Am J Cardiol. 1995;76(8):553–6. 31. Tischler MD, Niggel J, Borowski DT, et al. Relation between left ventricular shape and exercise capacity in patients with left ventricular dysfunction. J Am Coll Cardiol. 1993; 22(3):751–7.

1429

32. Massie BM, Schiller NB, Ratshin RA, et al. Mitral-septal separation: new echocardiographic index of left ventricular function. Am J Cardiol. 1977;39(7):1008–16. 33. D’Cruz IA, Lalmalani GG, Sambasivan V, et al. The superi ority of mitral E point-ventricular septum separation to other echocardiographic indicators of left ventricular per formance. Clin Cardiol. 1979;2(2):140–5. 34. Lehmann KG, Johnson AD, Goldberger AL. Mitral valve E point-septal separation as an index of left ventricular function with valvular heart disease. Chest. 1983;83(1): 102–8. 35. Schiller NB, Shah PM, Crawford M, et al. Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. American Society of Echocardiography Committee on Standards, Subcommittee on Quantitation of Two-Dimensional Echocardiograms. J Am Soc Echo cardiogr. 1989;2(5):358–67. 36. Schinkel AF, Bax JJ, Boersma E, et al. Assessment of residual myocardial viability in regions with chronic electrocardiographic Q-wave infarction. Am Heart J. 2002;144(5):865–9. 37. Mor-Avi V, Sugeng L, Lang RM. Real-time 3-dimensional echocardiography: an integral component of the routine echocardiographic examination in adult patients? Circu lation. 2009;119(2):314–29. 38. Arai K, Hozumi T, Matsumura Y, et al. Accuracy of measurement of left ventricular volume and ejection fraction by new real-time three-dimensional echocar diography in patients with wall motion abnormalities secondary to myocardial infarction. Am J Cardiol. 2004; 94(5):552–8. 39. Jenkins C, Bricknell K, Hanekom L, et al. Reproducibility and accuracy of echocardiographic measurements of left ventricular parameters using real-time three-dimen sional echocardiography. J Am Coll Cardiol. 2004;44(4): 878–86. 40. Nikitin NP, Constantin C, Loh PH, et al. New generation 3-dimensional echocardiography for left ventricular volumetric and functional measurements: comparison with cardiac magnetic resonance. Eur J Echocardiogr. 2006; 7(5):365–72. 41. Mor-Avi V, Jenkins C, Kühl HP, et al. Real-time 3-dimen sional echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error. JACC Cardiovasc Imaging. 2008;1(4):413–23. 42. Corsi C, Lang RM, Veronesi F, et al. Volumetric quantification of global and regional left ventricular function from real-time three-dimensional echocardiographic images. Circulation. 2005;112(8):1161–70. 43. Mulvagh SL, DeMaria AN, Feinstein SB, et al. Contrast echocardiography: current and future applications. J Am Soc Echocardiogr. 2000;13(4):331–42. 44. Migrino RQ, Young JB, Ellis SG, et al. End-systolic volume index at 90 to 180 minutes into reperfusion therapy for acute myocardial infarction is a strong predictor of early and late mortality. The global utilization of streptokinase

1430

45.

46.

47.

48.

49.

50.

51.

52.

53.

54.

55.

56.

57. 58.


and t-PA for occluded coronary arteries (GUSTO)-I angiographic investigators. Circulation. 1997;96(1):116–21. McManus DD, Shah SJ, Fabi MR, et al. Prognostic value of left ventricular end-systolic volume index as a predictor of heart failure hospitalization in stable coronary artery disease: data from the Heart and Soul Study. J Am Soc Echocardiogr. 2009;22(2):190–7. White HD, Norris RM, Brown MA, et al. Left ventricular end-systolic volume as the major determinant of survival after recovery from myocardial infarction. Circulation. 1987;76(1):44–51. Di Donato M, Castelvecchio S, Menicanti L. End-systolic volume following surgical ventricular reconstruction impacts survival in patients with ischaemic dilated cardio myopathy. Eur J Heart Fail. 2010;12(4):375–81. Vanoverschelde JL, Raphael DA, Robert AR, et al. Left ventricular filling in dilated cardiomyopathy: relation to functional class and hemodynamics. J Am Coll Cardiol. 1990;15(6):1288–95. Pinamonti B, Zecchin M, Di Lenarda A, et al. Persistence of restrictive left ventricular filling pattern in dilated cardiomyopathy: an ominous prognostic sign. J Am Coll Cardiol. 1997;29(3):604–12. Pinamonti B, Di Lenarda A, Sinagra G, et al. Restrictive left ventricular filling pattern in dilated cardiomyopathy assessed by Doppler echocardiography: clinical, echocar diographic and hemodynamic correlations and prognostic implications. Heart Muscle Disease Study Group. J Am Coll Cardiol. 1993;22(3):808–15. Shen WF, Tribouilloy C, Rey JL, et al. Prognostic significance of Doppler-derived left ventricular diastolic filling variables in dilated cardiomyopathy. Am Heart J. 1992;124(6): 1524–33. Whalley GA, Doughty RN, Gamble GD, et al. Pseudonormal mitral filling pattern predicts hospital re-admission in patients with congestive heart failure. J Am Coll Cardiol. 2002;39(11):1787–95. Sun JP, James KB, Yang XS, et al. Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus nondilated right ventricular cavities. Am J Cardiol. 1997;80(12):1583–7. de Groote P, Millaire A, Foucher-Hossein C, et al. Right ventricular ejection fraction is an independent predictor of survival in patients with moderate heart failure. J Am Coll Cardiol. 1998;32(4):948–54. Brieke A, DeNofrio D. Right ventricular dysfunction in chronic dilated cardiomyopathy and heart failure. Coron Artery Dis. 2005;16(1):5–11. Missant C, Rex S, Claus P, et al. Load-sensitivity of regional tissue deformation in the right ventricle: isovolumic versus ejection-phase indices of contractility. Heart. 2008; 94(4):e15. Williams L, Frenneaux M. Assessment of right ventricular function. Heart. 2008;94(4):404–5. Papavassiliou DP, Parks WJ, Hopkins KL, et al. Threedimensional echocardiographic measurement of right

ventricular volume in children with congenital heart dis ease validated by magnetic resonance imaging. J Am Soc Echocardiogr. 1998;11(8):770–7. 59. Kaul S, Tei C, Hopkins JM, et al. Assessment of right ventricular function using two-dimensional echocardio graphy. Am Heart J. 1984;107(3):526–31. 60. Ghio S, Recusani F, Klersy C, et al. Prognostic usefulness of the tricuspid annular plane systolic excursion in patients with congestive heart failure secondary to idiopathic or ischemic dilated cardiomyopathy. Am J Cardiol. 2000; 85(7):837–42. 61. La Vecchia L, Paccanaro M, Bonanno C, et al. Left ventri cular versus biventricular dysfunction in idiopathic dilated cardiomyopathy. Am J Cardiol. 1999;83(1):120–2, A129. 62. Kinch JW, Ryan TJ. Right ventricular infarction. N Engl J Med. 1994;330(17):1211–17. 63. Goldstein JA, Barzilai B, Rosamond TL, et al. Determinants of hemodynamic compromise with severe right ventricular infarction. Circulation. 1990;82(2):359–68. 64. Rossi A, Golia G, Gasparini G, et al. Left atrial filling volume can be used to reliably estimate the regurgitant volume in mitral regurgitation. J Am Coll Cardiol. 1999;33(1):212–17. 65. Rossi A, Cicoira M, Zanolla L, et al. Determinants and prognostic value of left atrial volume in patients with dilated cardiomyopathy. J Am Coll Cardiol. 2002;40(8):1425. 66. Dini FL, Cortigiani L, Baldini U, et al. Prognostic value of left atrial enlargement in patients with idiopathic dilated cardiomyopathy and ischemic cardiomyopathy. Am J Cardiol. 2002;89(5):518–23. 67. Moller JE, Hillis GS, Oh JK, et al. Left atrial volume: a powerful predictor of survival after acute myocardial infarction. Circulation. 2003;107(17):2207–12. 68. Simek CL, Feldman MD, Haber HL, et al. Relationship between left ventricular wall thickness and left atrial size: comparison with other measures of diastolic function. J Am Soc Echocardiogr. 1995;8(1):37–47. 69. Appleton CP, Galloway JM, Gonzalez MS, et al. Estimation of left ventricular filling pressures using two-dimensional and Doppler echocardiography in adult patients with cardiac disease. Additional value of analyzing left atrial size, left atrial ejection fraction and the difference in duration of pulmonary venous and mitral flow velocity at atrial contraction. J Am Coll Cardiol. 1993;22(7):1972–82. 70. Matsuda M, Matsuda Y. Mechanism of left atrial enlargement related to ventricular diastolic impairment in hypertension. Clin Cardiol. 1996;19(12):954–9. 71. Beinart R, Boyko V, Schwammenthal E, et al. Long-term prognostic significance of left atrial volume in acute myocardial infarction. J Am Coll Cardiol. 2004;44(2): 327–34. 72. Modena MG, Muia N, Sgura FA, et al. Left atrial size is the major predictor of cardiac death and overall clinical outcome in patients with dilated cardiomyopathy: a longterm follow-up study. Clin Cardiol. 1997;20(6):553–60. 73. Reed D, Abbott RD, Smucker ML, et al. Prediction of outcome after mitral valve replacement in patients with symptomatic chronic mitral regurgitation. The importance of left atrial size. Circulation. 1991;84(1):23–34.


74. Maddukuri PV, Vieira ML, DeCastro S, et al. What is the best approach for the assessment of left atrial size? Comparison of various unidimensional and two-dimensional parameters with three-dimensional echocardiographically determined left atrial volume. J Am Soc Echocardiogr. 2006;19(8): 1026–32. 75. Lester SJ, Ryan EW, Schiller NB, et al. Best method in clinical practice and in research studies to determine left atrial size. Am J Cardiol. 1999;84(7):829–32. 76. Tahta SA, Oury JH, Maxwell JM, et al. Outcome after mitral valve repair for functional ischemic mitral regurgitation. J Heart Valve Dis. 2002;11(1):11–18; discussion 18–19. 77. Barzilai B, Davis VG, Stone PH, et al. Prognostic significance of mitral regurgitation in acute myocardial infarction. The MILIS Study Group. Am J Cardiol. 1990;65(18):1169–75. 78. Tomita T, Nakatani S, Eishi K, et al. Effectiveness of surgical repair of mitral regurgitation concomitant with dilated cardiomyopathy. J Cardiol. 1998;32(6):391–6. 79. Blondheim DS, Jacobs LE, Kotler MN, et al. Dilated cardio myopathy with mitral regurgitation: decreased survival despite a low frequency of left ventricular thrombus. Am Heart J. 1991;122(3 Pt 1):763–71. 80. Borger MA, Alam A, Murphy PM, et al. Chronic ischemic mitral regurgitation: repair, replace or rethink? Ann Thorac Surg. 2006;81(3):1153–61. 81. Boltwood CM, Tei C, Wong M, et al. Quantitative echocar diography of the mitral complex in dilated cardiomyopathy: the mechanism of functional mitral regurgitation. Circu lation. 1983;68(3):498–508. 82. Trichon BH, O’Connor CM. Secondary mitral and tricuspid regurgitation accompanying left ventricular systolic dysfun ction: is it important, and how is it treated? Am Heart J. 2002;144(3):373–6. 83. Perloff JK, Roberts WC. The mitral apparatus. Func tional anatomy of mitral regurgitation. Circulation. 1972; 46(2):227–39. 84. Komeda M, Glasson JR, Bolger AF, et al. Geometric deter minants of ischemic mitral regurgitation. Circulation. 1997;96(9 Suppl):II-128–33. 85. Matsuzaki M, Yonezawa F, Toma Y, et al. Experimental mitral regurgitation in ischemia-induced papillary muscle dysfunction. J Cardiol Suppl. 1988;18:121–6, discussion 127. 86. Kaul S, Spotnitz WD, Glasheen WP. et al. Mechanism of ischemic mitral regurgitation. An experimental evaluation. Circulation. 1991;84(5):2167–80. 87. Kono T, Sabbah HN, Rosman H, et al. Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure. J Am Coll Cardiol. 1992;20(7):1594–8. 88. Otsuji Y, Kumanohoso T, Yoshifuku S, et al. Isolated annular dilation does not usually cause important functional mitral regurgitation: comparison between patients with lone atrial fibrillation and those with idiopathic or ischemic cardiomyopathy. J Am Coll Cardiol. 2002;39(10):1651–6. 89. He S, Fontaine AA, Schwammenthal E, et al. Integrated mechanism for functional mitral regurgitation: leaflet restriction versus coapting force: in vitro studies. Circu lation. 1997;96(6):1826–1834.

1431

90. Ogawa S, Hubbard FE, Mardelli TJ, et al. Cross-sectional echocardiographic spectrum of papillary muscle dysfu nction. Am Heart J. 1979;97(3):312–21. 91. Godley RW, Wann LS, Rogers EW, et al. Incomplete mitral leaflet closure in patients with papillary muscle dysfun ction. Circulation. 1981;63(3):565–71. 92. Otsuji Y, Handschumacher MD, Liel-Cohen N, et al. Mechanism of ischemic mitral regurgitation with segm ental left ventricular dysfunction: three-dimensional echocardiographic studies in models of acute and chronic progressive regurgitation. J Am Coll Cardiol. 2001;37(2): 641–8. 93. Yiu SF, Enriquez-Sarano M, Tribouilloy C, et al. Deter minants of the degree of functional mitral regurgitation in patients with systolic left ventricular dysfunction: A quan titative clinical study. Circulation. 2000;102(12):1400–6. 94. Agricola E, Oppizzi M, Maisano F, et al. Echocardiographic classification of chronic ischemic mitral regurgitation caused by restricted motion according to tethering pattern. Eur J Echocardiogr. 2004;5(5):326–34. 95. Karaca O, Avci A, Guler GB, et al. Tenting area reflects disease severity and prognosis in patients with nonischaemic dilated cardiomyopathy and functional mitral regurgitation. Eur J Heart Fail. 2011;13(3):284–91. 96. Calafiore AM, Gallina S, Di Mauro M, et al. Mitral valve procedure in dilated cardiomyopathy: repair or replacement? Ann Thorac Surg. 2001;71(4):1146–52; discu ssion 1152–1143. 97. Lee AP, Acker M, Kubo SH, et al. Mechanisms of recurrent functional mitral regurgitation after mitral valve repair in nonischemic dilated cardiomyopathy: importance of distal anterior leaflet tethering. Circulation. 2009;119(19): 2606–14. 98. Lesniak-Sobelga A, Wicher-Muniak E, Kostkiewicz M, et al. Relationship between mitral leaflets angles, left ventricular geometry and mitral deformation indices in patients with ischemic mitral regurgitation: imaging by echocardiography and cardiac magnetic resonance. Int J Cardiovasc Imag. 2012;28(1):59–67. 99. Nagasaki M, Nishimura S, Ohtaki E, et al. The echocardi ographic determinants of functional mitral regurgitation differ in ischemic and non-ischemic cardiomyopathy. Int J Cardiol. 2006;108(2):171–6. 100. Magne J, Pibarot P, Dagenais F, et al. Preoperative posterior leaflet angle accurately predicts outcome after restrictive mitral valve annuloplasty for ischemic mitral regurgitation. Circulation. 2007;115(6):782–91. 101. Kwan J, Shiota T, Agler DA, et al.; Real-time three-dimen sional echocardiography study. Geometric differ ences of the mitral apparatus between ischemic and dilated cardiomyopathy with significant mitral regurgitation: realtime three-dimensional echocardi ography study. Circu lation. 2003;107(8):1135–40. 102. Kim K, Kaji S, An Y, et al. Mechanism of asymmetric leaflet tethering in ischemic mitral regurgitation: 3D analysis with multislice CT. JACC Cardiovasc Imag. 2012;5(2):230–2.

1432


103. Nielsen SL, Nygaard H, Fontaine AA, et al. Papillary muscle misalignment causes multiple mitral regurgitant jets: an ambiguous mechanism for functional mitral regurgitation. J Heart Valve Dis. 1999;8(5):551–64. 104. Levi GS, Bolling SF, Bach DS. Eccentric mitral regurgitation jets among patients having sustained inferior wall myoc ardial infarction. Echocardiography. 2001;18(2): 97–103. 105. Watanabe N, Ogasawara Y, Yamaura Y, et al. Quantitation of mitral valve tenting in ischemic mitral regurgitation by transthoracic real-time three-dimensional echocardi ography. J Am Coll Cardiol. 2005;45(5):763–9. 106. Sawada SG, Segar DS, Ryan T, et al. Echocardiographic detection of coronary artery disease during dobutamine infusion. Circulation. 1991;83(5):1605–14. 107. Sharp SM, Sawada SG, Segar DS, et al. Dobutamine stress echocardiography: detection of coronary artery disease in patients with dilated cardiomyopathy. J Am Coll Cardiol. 1994;24(4):934–9. 108. Marcovitz PA, Armstrong WF. Accuracy of dobutamine stress echocardiography in detecting coronary artery disease. Am J Cardiol. 1992;69(16):1269–73. 109. Senior R, Lahiri A. Enhanced detection of myocardial ischemia by stress dobutamine echocardiography utilizing the “biphasic” response of wall thickening during low and high dose dobutamine infusion. J Am Coll Cardiol. 1995;26(1):26–32. 110. Sawada SG, Ryan T, Segar D, et al. Distinguishing ischemic cardiomyopathy from nonischemic dilated cardiomyopathy with coronary echocardiography. J Am Coll Cardiol. 1992;19(6):1223–8. 111. Chandraratna PA, Aronow WS. Left main coronary arterial patency assessed with cross-sectional echocardiography. Am J Cardiol. 1980;46(1):91–4. 112. Chen CC, Morganroth J, Ogawa S, et al. Detecting left main coronary artery disease by apical, cross-sectional echocardiography. Circulation. 1980;62(2):288–93. 113. Ryan T, Armstrong WF, Feigenbaum H. Prospective eval uation of the left main coronary artery using digital two-dimensional echocardiography. J Am Coll Cardiol. 1986;7(4):807–12. 114. Dittrich HC, Bales GL, Kuvelas T, et al. Myocardial contrast echocardiography in experimental coronary artery occl usion with a new intravenously administered contrast agent. J Am Soc Echocardiogr. 1995;8(4):465–74. 115. Meza M, Greener Y, Hunt R, et al. Myocardial contrast echocardiography: reliable, safe, and efficacious myocardial perfusion assessment after intravenous injections of a new echocardiographic contrast agent. Am Heart J. 1996;132(4):871–81. 116. Beppu S, Matsuda H, Shishido T, et al. Prolonged myo cardial contrast echocardiography via peripheral venous administration of QW3600 injection (EchoGen): its efficacy and side effects. J Am Soc Echocardiogr. 1997;10(1):11–24. 117. Grauer SE, Pantely GA, Xu J, et al. Myocardial imaging with a new transpulmonary lipid-fluorocarbon echo contrast agent: experimental studies in pigs. Am Heart J. 1996; 132(5):938–45.

118. Neglia D, Michelassi C, Trivieri MG, et al. Prognostic role of myocardial blood flow impairment in idiopathic left ventricular dysfunction. Circulation. 2002;105(2):186–93. 119. Goldman MR, Boucher CA. Value of radionuclide imaging techniques in assessing cardiomyopathy. Am J Cardiol. 1980;46(7):1232–6. 120. Herman MV, Heinle RA, Klein MD, et al. Localized disorders in myocardial contraction. Asynergy and its role in congestive heart failure. N Engl J Med. 1967;277(5): 222–32. 121. Medina R, Panidis IP, Morganroth J, et al. The value of echocardiographic regional wall motion abnormalities in detecting coronary artery disease in patients with or without a dilated left ventricle. Am Heart J. 1985;109(4):799–803. 122. Chen YZ, Sherrid MV, Dwyer EM Jr. Value of two dimensional echocardiography in evaluating coronary artery disease: a randomized blinded analysis. J Am Coll Cardiol. 1985;5(4):911–17. 123. Bulkley BH, Hutchins GM, Bailey I, et al. Thallium 201 imaging and gated cardiac blood pool scans in patients with ischemic and idiopathic congestive cardiomyopathy. A clinical and pathologic study. Circulation. 1977;55(5): 753–60. 124. Mathes P, Sebening H, Wirtzfeld A, et al. Regional contraction of the left ventricle in congestive cardiomyopathy. Dtsch Med Wochenschr. 1976;101(26): 995–9. 125. Schoolmeester WL, Simpson AG, Sauerbrunn BJ, et al. Radionuclide angiographic assessment of left ventricular function during exercise in patients with a severely reduced ejection fraction. Am J Cardiol. 1981;47(4):804–9. 126. Roberts WC, Siegel RJ, McManus BM. Idiopathic dilated cardiomyopathy: analysis of 152 necropsy patients. Am J Cardiol. 1987;60(16):1340–55. 127. Heger JJ, Weyman AE, Wann LS, et al. Cross-sectional echocardiographic analysis of the extent of left ventricular asynergy in acute myocardial infarction. Circulation. 1980;61(6):1113–8. 128. Wallis DE, O’Connell JB, Henkin RE, et al. Segmental wall motion abnormalities in dilated cardiomyopathy: a common finding and good prognostic sign. J Am Coll Cardiol. 1984;4(4):674–9. 129. Greenberg JM, Murphy JH, Okada RD, et al. Value and limitations of radionuclide angiography in determining the cause of reduced left ventricular ejection fraction: comparison of idiopathic dilated cardiomyopathy and coronary artery disease. Am J Cardiol. 1985;55(5):541–4. 130. Iskandrian AS, Helfeld H, Lemlek J, et al. Differentiation between primary dilated cardiomyopathy and ischemic cardiomyopathy based on right ventricular performance. Am Heart J. 1992;123(3):768–73. 131. Inoue T, Sakai Y, Morooka S, et al. Vasodilatory capacity of coronary resistance vessels in dilated cardiomyopathy. Am Heart J. 1994;127(2):376–81. 132. Chen JW, Ting CT, Chen YH, et al. Differential coronary microvascular function in patients with left ventricular dysfunction of unknown cause–implication for possible mechanism of myocardial ischemia in early stage of cardiomyopathy. Int J Cardiol. 1999;69(3):251–61.


133. Duncan AM, Francis DP, Gibson DG, et al. Differentiation of ischemic from nonischemic cardiomyopathy during dobutamine stress by left ventricular long-axis function: additional effect of left bundle-branch block. Circulation. 2003;108(10):1214–20. 134. Lewis JF, Webber JD, Sutton LL, et al. Discordance in degree of right and left ventricular dilation in patients with dilated cardiomyopathy: recognition and clinical implications. J Am Coll Cardiol. 1993;21(3):649–54. 135. Nanda NC, Hsiung MC, Miller AP, et al. Left ventricular and right ventricular and function assessment, in live/real time 3D echocardiography. 2010. 136. Lima RS, Watson DD, Goode AR, et al. Incremental value of combined perfusion and function over perfusion alone by gated SPECT myocardial perfusion imaging for detection of severe three-vessel coronary artery disease. J Am Coll Cardiol. 2003;42(1):64–70. 137. Salerno M, Kramer CM. Advances in cardiovascular MRI for diagnostics: applications in coronary artery disease and cardiomyopathies. Expert Opin Med Diagn. 2009;3(6): 673–87. 138. Schinkel AF, Elhendy A, van Domburg RT, et al. Incremental value of exercise technetium-99m tetrofosmin myocardial perfusion single-photon emission computed tomography for the prediction of cardiac events. Am J Cardiol. 2003;91(4):408–11. 139. Cannon RO 3rd, Cunnion RE, Parrillo JE, et al. Dynamic limitation of coronary vasodilator reserve in patients with dilated cardiomyopathy and chest pain. J Am Coll Cardiol. 1987;10(6):1190–200. 140. Klocke FJ, Baird MG, Lorell BH, et al. ACC/AHA/ASNC guidelines for the clinical use of cardiac radionuclide imaging–executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASNC Comm ittee to revise the 1995 guidelines for the clinical use of cardiac radionuclide imaging). Circulation. Sep 16 2003; 108(11):1404–18. 141. Shaw LJ, Iskandrian AE. Prognostic value of gated myocardial perfusion SPECT. J Nucl Cardiol. 2004;11(2):171–85. 142. Hakeem A, Bhatti S, Dillie KS, et al. Predictive value of myocardial perfusion single-photon emission computed tomography and the impact of renal function on cardiac death. Circulation. 2008;118(24):2540–9. 143. Eichhorn EJ, Kosinski EJ, Lewis SM, et al. Usefulness of dipyridamole-thallium-201 perfusion scanning for disting uishing ischemic from nonischemic cardiomyopathy. Am J Cardiol. 1988;62(13):945–51. 144. Tauberg SG, Orie JE, Bartlett BE, et al. Usefulness of thallium-201 for distinction of ischemic from idiopathic dilated cardiomyopathy. Am J Cardiol. 1993;71(8):674–80. 145. Shiotani H, Yamabe H, Fukuzaki H. The clinical and prognostic significance of dipyridamole Tl-201 emission computed tomography in patients with dilated cardio myopathy. Jpn Circ J. 1987;51(9):1016–21.

1433

146. Dunn RF, Uren RF, Sadick N, et al. Comparison of thallium-201 scanning in idiopathic dilated cardiomyopathy and severe coronary artery disease. Circulation. 1982;66(4): 804–10. 147. Danias PG, Ahlberg AW, Clark BA 3rd, et al. Combined assessment of myocardial perfusion and left ventricular function with exercise technetium-99m sestamibi gated single-photon emission computed tomography can differentiate between ischemic and nonischemic dilated cardiomyopathy. Am J Cardiol. 1998;82(10):1253–8. 148. Yao SS, Qureshi E, Nichols K, et al. Prospective validation of a quantitative method for differentiating ischemic versus nonischemic cardiomyopathy by technetium-99m sesta mibi myocardial perfusion single-photon emission comp uted tomography. Clin Cardiol. 2004;27(11):615–20. 149. Schuijf JD, Shaw LJ, Wijns W, et al. Cardiac imaging in coronary artery disease: differing modalities. Heart. 2005;91(8):1110–7. 150. Raff GL, Gallagher MJ, O’Neill WW, et al. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. J Am Coll Cardiol. 2005;46(3):552–7. 151. Janowitz WR, Agatston AS, Viamonte M Jr. Comparison of serial quantitative evaluation of calcified coronary artery plaque by ultrafast computed tomography in persons with and without obstructive coronary artery disease. Am J Cardiol. 1991;68(1):1–6. 152. Leber AW, Knez A, von Ziegler F, et al. Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound. J Am Coll Cardiol. 2005;46(1):147–54. 153. Andreini D, Pontone G, Pepi M, et al. Diagnostic accuracy of multidetector computed tomography coronary angio graphy in patients with dilated cardiomyopathy. J Am Coll Cardiol. 2007;49(20):2044–50. 154. Budoff MJ, Shavelle DM, Lamont DH, et al. Usefulness of electron beam computed tomography scanning for distinguishing ischemic from nonischemic cardiom yopathy. J Am Coll Cardiol. 1998;32(5):1173–8. 155. Andreini D, Pontone G, Bartorelli AL, et al. Sixty-four-slice multidetector computed tomography: an accurate imaging modality for the evaluation of coronary arteries in dilated cardiomyopathy of unknown etiology. Circ Cardiovasc Imaging. 2009;2(3):199–205. 156. Ghostine S, Caussin C, Habis M, et al. Non-invasive diagnosis of ischaemic heart failure using 64-slice comp uted tomography. Eur Heart J. 2008;29(17):2133–40. 157. Lima JA, Hare J. Visualizing the coronaries in patients presenting with heart failure of unknown etiology. J Am Coll Cardiol. 2007;49(20):2051–2. 158. Androulakis AE, Andrikopoulos GK, Richter DJ, et al. The role of carotid atherosclerosis in the distinction between ischaemic and non-ischaemic cardiomyopathy. Eur Heart J. 2000;21(11):919–26.

1434


159. Le T, Ko JY, Kim HT, Akinwale P, et al. Comparison of echocardiography and electron beam tomography in differentiating the etiology of heart failure. Clin Cardiol. 2000;23(6):417–20. 160. Shemesh J, Tenenbaum A, Fisman EZ, et al. Coronary calcium as a reliable tool for differentiating ischemic from nonischemic cardiomyopathy. Am J Cardiol. 1996;77(2): 191–4. 161. Rajappan K, Bellenger NG, Anderson L, et al. The role of cardiovascular magnetic resonance in heart failure. Eur J Heart Fail. 2000;2(3):241–52. 162. Doherty NE 3rd, Seelos KC, Suzuki J, et al. Application of cine nuclear magnetic resonance imaging for sequential evaluation of response to angiotensin-converting enzyme inhibitor therapy in dilated cardiomyopathy. J Am Coll Cardiol. 1992;19(6):1294–302. 163. Danias PG, Roussakis A, Ioannidis JP. Diagnostic perfor mance of coronary magnetic resonance angiography as compared against conventional X-ray angiography: a meta-analysis. J Am Coll Cardiol. 2004;44(9):1867–76. 164. Kim RJ, Wu E, Rafael A, et al. The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction. N Engl J Med. 2000;343(20): 1445–53. 165. Nandalur KR, Dwamena BA, Choudhri AF, et al. Diagnostic performance of stress cardiac magnetic resonance imaging in the detection of coronary artery disease: a meta-analysis. J Am Coll Cardiol. 2007;50(14):1343–53. 166. Simonetti OP, Kim RJ, Fieno DS, et al. An improved MR imaging technique for the visualization of myocardial infarction. Radiology. 2001;218(1):215–23. 167. McCrohon JA, Moon JC, Prasad SK, et al. Differentiation of heart failure related to dilated cardiomyopathy and coronary artery disease using gadolinium-enhanced cardiovascular magnetic resonance. Circulation. 2003;108(1):54–9.

168. Soriano CJ, Ridocci F, Estornell J, et al. Noninvasive diag nosis of coronary artery disease in patients with heart failure and systolic dysfunction of uncertain etiology, using late gadolinium-enhanced cardiovascular magnetic resonance. J Am Coll Cardiol. 2005;45(5):743–8. 169. Wu E, Judd RM, Vargas JD, et al. Visualisation of presence, location, and transmural extent of healed Q-wave and nonQ-wave myocardial infarction. Lancet. 2001;357(9249): 21–8. 170. Izawa H, Murohara T, Nagata K, et al. Mineralocorticoid receptor antagonism ameliorates left ventricular diastolic dysfunction and myocardial fibrosis in mildly symptomatic patients with idiopathic dilated cardiomyopathy: a pilot study. Circulation. 2005;112(19):2940–5. 171. Assomull RG, Prasad SK, Lyne J, et al. Cardiovascular magnetic resonance, fibrosis, and prognosis in dilated cardiomyopathy. J Am Coll Cardiol. 2006;48(10):1977–85. 172. de Leeuw N, Ruiter DJ, Balk AH, et al. Histopathologic findings in explanted heart tissue from patients with endstage idiopathic dilated cardiomyopathy. Transpl Int. 2001; 14(5):299–306. 173. Knaapen P, Boellaard R, Götte MJ, et al. Perfusable tissue index as a potential marker of fibrosis in patients with idiopathic dilated cardiomyopathy. J Nucl Med. 2004; 45(8):1299–304. 174. Berry JJ, Hoffman JM, Steenbergen C, et al. Human pathologic correlation with PET in ischemic and non ischemic cardiomyopathy. J Nucl Med. 1993;34(1): 39–47. 175. Geltman EM. Metabolic imaging of patients with cardio myopathy. Circulation. 1991;84(3 Suppl):I265–I272. 176. Bengel FM, Higuchi T, Javadi MS, et al. Cardiac positron emission tomography. J Am Coll Cardiol. 2009;54(1):1–15. 177. Eisenberg JD, Sobel BE, Geltman EM. Differentiation of ischemic from nonischemic cardiomyopathy with positron emission tomography. Am J Cardiol. 1987;59(15):1410–14.

CHAPTER 68 Pericardial Disease Trevor Jenkins, Brian D Hoit

Snapshot  Acute Pericardi s  Pericardial Effusion  M-Mode and Two-Dimensional Echocardiography  Pericardial Tamponade

INTRODUCTION Pericardial heart disease represents a spectrum of conditions with significant mortality and morbidity commonly encountered in cardiovascular medicine. Normal pericardial anatomy was first described in antiquity, while descriptions of pericardial pathology appeared during the 17th to 18th centuries.1 Ultrasound visualization of the pericardium has advanced rapidly during recent decades and has become an essential tool for diagnosis and management of pericardial heart disease. The value of echocardiography in this regard is the ability to display both structure and physiology at high spatial and temporal resolution. Efforts to visualize pericardial disease originate with the early days of cardiac ultrasound. Inge Edler first published images of an anterior pericardial effusion in 1961.2 Harvey Feigenbaum published several early manuscripts documenting the power of echocardiography to display pericardial effusions and published the relation between the “swinging heart” in cardiac tamponade by M-mode with electrical alternans by electrocardiography (ECG).3 Such early observations helped expand the scope of echocardiography beyond detection of mitral stenosis.4

 Constric ve Pericardi s  Effusive-Constric ve Pericardi s  Congenital Anomalies  Mul modality Imaging of the Pericardium

Anatomy and Echocardiographic Appearance The pericardium is an avascular tissue comprising two histologically distinct layers—the visceral pericardium, a serosal single cell layer adherent to the epicardium and great vessels; and the parietal pericardium, a thick fibrous outer layer. A potential space is enclosed between these two layers, which normally contains 15–35 mL of serous fluid distributed mostly over the atrial–ventricular and interventricular grooves.5 This fluid serves as a lubricant during cardiac motion. Pericardial reflections around the proximal ascending aorta, central pulmonary arteries, pulmonary veins, and venae cavae form the oblique and transverse sinuses. The fibrous parietal pericardium is less distensible than myocardium, a property that functionally limits myocardial chamber distention.6,7 The normal pericardium is usually not well visualized by two-dimensional (2D) echocardiography. The typical appearance is that of a thin, bright, highly echogenic line denoting the intersection of parietal pericardium and lung tissue. The normal pericardium by computed tomography (CT) is < 2 mm in diameter. Thickening of the pericardium (> 5 mm diameter) may allow for direct visualization.

1436


Normally, a trace amount of pericardial fluid may be seen at end-systole.

Physiology and Pathophysiology The pericardium is not essential for life as no adverse consequences follow congenital absence or surgical removal of the pericardium. However, the pericardium serves many important functions (Table 68.1). Most relevant to echocardiographic evaluation, it limits distension of the cardiac chambers, and facilitates interaction and coupling of the ventricles and atria.8 Pericardial restraint of ventricular filling becomes significant when the pericardial reserve volume (the normally small difference between unstressed pericardial volume and cardiac volume) is exceeded. This may occur with rapid increases in blood volume and in disease states characterized by rapid increases in heart size, such as acute mitral and tricuspid regurgitation. In contrast, chronic stretching of the pericardium results in “stress relaxation” and “creep” (decreased pericardial pressure and increased in volume with constant stretch, respectively, owing to viscoelastic properties of the pericardium) and cellular hypertrophy, which explains why large but slowly developing effusions do not produce tamponade.8 In view of the pericardium’s simple structure, clinicopathological processes involving it are understandably few and includes only pericarditis and its complications, tamponade and constriction, and congenital lesions. However, the pericardium is affected by virtually every category of disease, including infectious, neoplastic, immune-inflammatory, metabolic, iatrogenic, traumatic, Table 68.1: Functions of Pericardium

Mechanical Effects on individual chambers: •

Constrains chamber distention during cardiac cycle

• Modulates cardiac chamber interaction and coupling • Maintains left ventricular geometric shape • Preserves pressure–volume relation of the cardiac chambers Effects on entire heart: • Lubrication and friction reduction

and congenital etiologies. Thus, pericardial disease may present either as an isolated phenomenon or as a complication of a variety of systemic disorders, trauma, or certain drugs. In these settings, pericardial involvement may be overshadowed by extracardiac manifestations and difficult to recognize.8 This chapter will review the echocardiographic findings in each of these conditions.

ACUTE PERICARDITIS Acute pericarditis may be isolated or present as a manifestation of a systemic process. Although the etiology is highly variable, most cases of acute pericarditis are idiopathic or viral. Inflammation of the pericardium is usually silent echocardiographically, as echogenic brightness of the pericardium lacks sufficient diagnostic sensitivity and specificity. Echocardiography is recommended as the initial noninvasive imaging test for acute pericarditis, because it accurately detects pericardial effusion and tamponade, and ventricular dysfunction due to myopericarditis.9 Echocardiography estimates the volume of pericardial fluid, identifies cardiac tamponade, suggests the basis of pericarditis, and documents associated acute myocarditis. In addition, the presence of adhesions, fibrous strands, hemorrhage, and loculations may aid in the diagnosis of morbid conditions such as purulent bacterial pericarditis that may require pericardiocentesis. Although patients with purely fibrinous acute pericarditis have a normal echocardiogram, the presence of a pericardial effusion is consistent with acute pericarditis and is one of the criteria for its diagnosis. A transthoracic echocardiogram (TTE) is particularly critical in the setting of high-risk features of acute pericarditis associated with worse outcome including fever > 38°C, subacute onset, an immunosupressed state, trauma, or evidence of hemodynamic compromise.10 The use of echocardiography for the evaluation of all patients with suspected pericardial disease was given a Class I recommendation by a 2003 task force of the American College of Cardiology (ACC), the American Heart Association (AHA), and the American Society of Echocardiography (ASE).11 Additional imaging modalities may be necessary if the TTE is negative or inconclusive in a patient with complex or atypical clinical presentations.

• Mechanical barrier to infection • Balances inertial hydrostatic and gravitational forces Miscellaneous (vasomotor, immunological, fibrinolytic, regulation of localized gene and protein expression)

PERICARDIAL EFFUSION Accumulation of transudative or exudative fluid in excess of 50 mL is abnormal and may be seen with pericarditis

Chapter 68: Pericardial Disease

Table 68.2: Etiology of Pericarditis

Idiopathic: • Infectious (viral, bacterial, mycobacterial, fungal, or AIDS/HIV) • Autoimmune (systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, or ankylosing spondylitis) • Neoplastic [primary (mesothelioma), secondary (breast, lung, melanoma, lymphoma)] Radiotherapy: • Nephrogenic (uremic, dialytic) • Cardiac injury (surgery, interventional, trauma) [acute

or

chronic

of cases. In the remainder, patients with evidence of an inflammatory process were most likely to have acute idiopathic pericarditis, while those without inflammatory signs or tamponade were more likely to have a chronic idiopathic effusion, and those with cardiac tamponade but without inflammatory signs most commonly had a malignant effusion.14

M-MODE AND TWO-DIMENSIONAL ECHOCARDIOGRAPHY

• Metabolic (drugs, myxedema, amyloidosis)

• Myocardial infarction syndrome)]

1437

(Dressler’s

of any etiology (Table 68.2). Pericardial effusions are very common after cardiac surgery. In 122 consecutive patients studied before and serially after cardiac surgery, effusions were present in 103 patients; the majority appeared by postoperative day 2, reached their maximum size by postoperative day 10, and usually resolved without sequelae within the first postoperative month.12 However, large effusions or effusions causing pericardial tamponade are uncommon following cardiothoracic surgery. In one retrospective survey of more than 4,500 postoperative patients, only 48 were found to have moderate or large effusions by echocardiography; of those, 36 met diagnostic criteria for tamponade.13 Effusion should be suspected and an echocardiogram obtained in all patients who present with chest pain consistent with pericarditis or aortic dissection, an enlarged (typically “flask shaped”) cardiac silhouette seen on chest radiogram, systemic disease associated with pericardial effusion accompanied by jugular venous distension, after a myocardial infarction, or in patients who develop hypotension or hemodynamic instability in the setting of interventional cardiac procedures. However, asymptomatic pericardial effusions are often discovered during the evaluation of an unrelated medical complaint or disorder. Chronic effusive pericarditis is an entity of unknown etiology that may be associated with large, asymptomatic effusions. Many conditions that cause pericarditis (e.g. uremia, tuberculosis, neoplasia, connective tissue disease) produce chronic pericardial effusions. In a series of 322 patients admitted to a tertiary care hospital with at least a moderate-sized pericardial effusion, the cause was attributed to a preexisting medical condition in 60%

Echo is the initial procedure of choice to detect the presence of a pericardial effusion because it is portable, noninvasive, can be performed with minimal delay, and attention to technical detail results in excellent sensitivity and specificity. The diagnostic feature on M-mode echocardiography is the persistence of an echo-free space between parietal and visceral pericardium throughout the cardiac cycle. Separations that are observed only in systole represent clinically insignificant accumulations. The superior spatial orientation of 2D echo allows delineation of the size and distribution of pericardial effusion, as well as detection of loculated fluid. As the amount of pericardial fluid increases, fluid distributes from the posterobasilar left ventricle (LV) apically and anteriorly, and then laterally and posteriorly to the left atrium (LA). Fluid adjacent to the right atrium (RA) is an early sign of pericardial effusion. A left pleural effusion may mimic a pericardial effusion on M-mode, in which cases fluid anterior to the descending aortic on a 2D echo parasternal long axis establishes the fluid as pericardial rather than pleural, which is posterior to the aorta15 (Figs 68.1 and 68.2). The size of a pericardial effusion on 2D echo is qualitatively described by the end-diastolic distance of the echo-free space between the parietal and visceral pericardium: trivial (seen only in systole), small (< 10 mm), moderate (10–20 mm), large (> 20 mm), or very large (> 2.5 cm); an even distribution of the effusion sampled from multiple 2D transducer positions increases the predictive accuracy of the estimate. 2D echo also allows for the detection of fluid that may be loculated, or an echodensity more consistent with an exudate or clot rather than a transudate. Exudative pericardial effusions may show features such as stranding, adhesions, or an uneven distribution reflecting a more inflammatory composition; finding these frond-like, band-like, or shaggy intrapericardial echoes should alert one to the possibility of a difficult and potentially less therapeutic

1438


A

B

C

D

Figs 68.1A to D: Two-dimensional (2D) echocardiography of pericardial effusions of varying size. Anterior (*) and posterior (arrow) are seen as echo-free spaces of increasing size including small, posterior (A), moderate circumferential (B), and large circumferential (C). Figure D shows a large pleural effusion (curved arrow) posterior to a small pericardial effusion (arrow) with the pericardium visualized as an echogenic linearity between both. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

pericardiocentesis and a more complicated course, but have little value in identifying the cause of the effusion (Figs 68.3A and B). Pericardial effusions that contain clots (e.g. after cardiac surgery), may be missed on a TTE and may require transesophageal echo (TEE), CT, or cardiac magnetic resonance imaging (CMR). Distinguishing epicardial fat from (particularly anterior) pericardial effusion may be difficult, but epicardial fat is slightly echogenic and moves in concert with the heart, whereas pericardial effusion is generally echolucent and motionless. Epicardial fat may appear circumferentially (fat envelope) and be difficult to discern. In addition to its mimicry, pericardial fat accumulation is a source of bioactive molecules, is significantly associated

with obesity-related insulin resistance, and is a coronary risk factor16 (Fig. 68.4).

PERICARDIAL TAMPONADE Cardiac tamponade is a life-threatening condition caused by fluid accumulation in the pericardial sac and is characterized by elevation and equalization of cardiac diastolic and pericardial pressures, a reduced cardiac output, and an exaggerated inspiratory decrease in arterial systolic pressure (>10 mm Hg) referred to as pulsus paradoxus. Cardiac tamponade is poorly related to the size of the effusion, as it is the rapidity of fluid accumulation in the pericardial space and the eclipse of pericardial reserve


A

B

C

D

1439

Figs 68.2A to D: M-mode echocardiography of pericardial effusions of varying size. Anterior (*) and posterior (arrow) are seen as echo-free spaces of increasing size including small, posterior (A), moderate circumferential (B), and large circumferential (C). Concurrent pleural (curved arrow) and pericardial effusion are shown in Figure D. Note that parietal pericardium displays relatively flat motion throughout the cardiac cycle best visualized in Figure C. (LV: Left ventricle; RV: Right ventricle).

A

B

Figs 68.3A and B: Exudative pericardial effusions as seen by two-dimensional (2D) echocardiography apical views. Frond-like (A) and band-like (B) adhesions are seen bridging a large pericardial effusion fluid, indicating an inflammatory component to the effusion. Note the thickened pericardium in Figure A. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1440


Fig. 68.4: An echo-clear space (arrow) is seen anterior to the pericardium due to epicardial fat. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

volume that elevates pericardial pressure and interferes with cardiac filling. Cardiac tamponade may be acute or subacute–chronic and should be viewed hemodynamically as a continuum ranging from mild (pericardial pressure lower than 10 mm Hg) to severe (pericardial pressure higher than 15–20 mm Hg). Mild cardiac tamponade may cause few symptoms, whereas moderate tamponade and especially severe tamponade produce precordial discomfort, dyspnea, and a sense of doom. Patients who are severely hypovolemic due to hemorrhage, dialysis, or overdiuresis may have low pressure tamponade in which the intracardiac and pericardial diastolic pressures are < 10 mm Hg. In a series of 279 patients who underwent combined pericardiocentesis and cardiac catheterization, 143 patients (51%) were diagnosed with cardiac tamponade defined as intrapericardial pressures equal to RA pressure prior to pericardiocentesis.17 Low pressure cardiac tamponade was diagnosed in 29 patients (10%) who had an initial intrapericardial pressure of < 7 mm Hg and a RA pressure after pericardiocentesis of < 4 mm Hg. Clinical findings commonly associated with cardiac tamponade, such as sinus tachycardia, jugular venous distention, and pulsus paradoxus were less common in the low pressure group. However, the hemodynamic significance of these effusions could be demonstrated on echo by right heart chamber collapse and respiratory variations in Doppler transvalvular flow velocities, despite the absence of vena caval plethora. In the absence of clinical signs of

tamponade, urgent pericardiocentesis is usually not necessary, but careful monitoring is warranted. Tamponade may also be regional. A loculated, eccentric effusion, or localized hematoma can produce regional tamponade in which only selected chambers are compressed. As a result, the typical physical, hemodynamic, and echocardiographic signs of tamponade are often absent. Regional tamponade is most often seen after pericardiotomy or myocardial infarction; clinical suspicion should be heightened in these settings. Establishing the diagnosis is challenging and may require additional echocardiographic views (e.g. transesophageal) and other advanced imaging techniques (e.g. CT, CMR). When cardiac tamponade is suspected, a 2D echo with Doppler should be obtained emergently unless a delay might prove life-threatening. CT and CMR are used only for complicated cases such as postoperative or loculated effusions. While there are many echo signs of tamponade, the most important ones are the presence of a pericardial effusion, dilated (plethoric) inferior vena cava (IVC) and hepatic veins (which indicate that systemic venous pressures are elevated), and a LV with reduced enddiastolic and systolic dimensions with Doppler evidence of reduced stroke volume and cardiac output. In most cases of cardiac tamponade, other “classic” echo-Doppler findings are also present and confirm the diagnosis. These signs include right heart diastolic chamber collapses (when pericardial pressures exceed intracardiac pressure), an inspiratory bulge or “bounce” of the interventricular septum into the LV, and characteristic abnormal respiratory changes in Doppler flow velocity recordings.

M-Mode and Two-Dimensional Echo Two-dimensional echo imaging from standard transducer positions establishes the qualitative size of the effusion, its distribution, and to an extent, the nature of the effusion. When cardiac tamponade is present with a moderate or large effusion, the LV cavity dimensions are reduced, and because mass is conserved, the wall thickness is increased (“pseudohypertrophy”)18 (Figs 68.5A and B). When the effusion is massive, the heart swings freely in the pericardial space and displays a pendular motion that is associated with electrical alternans (Movie clip 1). Right ventricular end-diastolic diameter increases during inspiration while reciprocally, LV end-diastolic diameter decreases; opposite changes are seen during expiration (see below). An important sign of tamponade


A

1441

B

Figs 68.5A and B: Pseudohypertrophy (A) is demonstrated in the setting of a large pericardial effusion with tamponade physiology with normalization; (B) of left ventricular wall thickness after pericardiocentesis.

Fig. 68.6: Plethora (dilation) of the inferior vena cava (IVC) indicative of elevated central venous filling pressure in the setting of tamponade. (L: Liver).

that should be carefully sought is IVC plethora, defined as dilation of the IVC and hepatic veins with < 50% reduction in diameter during inspiration. In one series, IVC plethora was present in 92% of pericardial effusions that were associated with pulsus paradoxus and which required pericardial drainage.19 Although IVC dilation is highly sensitive for cardiac tamponade, it is a nonspecific sign indicating elevated right heart pressures and therefore is seen in heart diseases in which a pericardial effusion is absent (Fig. 68.6). Diastolic RA and right ventricle (RV) chamber invagination or “collapses” on 2D echo are usually seen

in cardiac tamponade and are particularly valuable in the diagnosis of low pressure tamponade when IVC dilation is minimal or absent. The subcostal view is often the best to visualize RA and RV chamber collapse. The superior temporal resolution of M-mode echo makes it ideal for judging the timing and duration of collapse. Occasionally, LA and LV chamber collapses are observed (Figs 68.7A and B). Chamber collapses indicate transient negative transmural pressure and occur during their respective relaxation phase when intracavitary pressure reaches its nadir.20 Thus, atrial collapse begins at end-diastole near the peak of the R-wave, while ventricular collapse begins in early diastole after the end of the T-wave. In general, specificity of collapses is greater and tamponade more severe, the longer the duration of compression. Brief RA collapse is sensitive but not specific, whereas RA collapse that exceeds one-third of the cardiac cycle is nearly 100% sensitive and specific for clinical cardiac tamponade.21 RV diastolic collapse generally occurs when cardiac output has decreased about 20% from baseline but before systemic blood pressure has fallen; initially, it is seen only during inspiration, but as tamponade becomes more severe it occurs throughout the respiratory cycle22 (Movie clip 2). Experimental studies indicate that right heart chamber collapse occurs earlier than pulsus paradoxus, and that the sensitivity and specificity of chamber collapse improves as the severity of tamponade increases. These studies also suggest that RA chamber collapse may have a higher predictive value than RV collapse.23

1442


A

B

Figs 68.7A and B: Two-dimensional (2D) echocardiograms in the apical four-chamber view demonstrating chamber collapse due to tamponade. During late diastole, there is inversion of the right atrial lateral wall (A), and right ventricular free wall (B). (AO: Aorta; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Table 68.3: Sensitivity and Specificity of Right Heart Chamber Collapses in Cardiac Tamponade

Sensitivity (%) Specificity (%) Any chamber

90

65

Right atrium

68

66

Right ventricle

60

90

Simultaneous right atrium/ right ventricle (RA/RV)

45

92

Source: Modified from Reference 24.

Although the sensitivity and specificity of collapses are variable (Table 68.3), the absence of any cardiac chamber collapse has > 90% negative predictive value for clinical cardiac tamponade.24 However, right heart diastolic collapse may occur only at higher levels of pericardial pressure, or may be absent in conditions in which right heart chamber pressures are elevated before the effusion accumulated, as may be seen with RV hypertrophy and severe pulmonary hypertension. Conversely, collapse of the right heart chamber may occur earlier than normal when intracardiac pressures are low owing to hypovolemia or with coexisting severe LV dysfunction.25,26 Posterior loculated effusions after cardiac surgery and severe pulmonary arterial hypertension may produce LA and LV diastolic collapse. As indicated earlier, establishing the diagnosis of regional tamponade is challenging and may require nontraditional echo views, TEE, CT, or CMR.

In cardiac tamponade, inspiration lowers right heart pressures and augments systemic venous return as it does in normal individuals. However, unlike the minimal (< 5%) change in left-sided filling during normal inspiration in normal individuals, left heart filling decreases abnormally in cardiac tamponade, resulting in a reduced stroke volume and the appearance of pulsus paradoxus. This phenomenon is due to enhanced ventricular interdependence, wherein an increase in filling on one side of the heart is associated with a decrease on the opposite side. Thus, during inspiration there is an increase in RV dimension and a decrease in LV dimension that is due to septal movement toward the LV free wall (and a decrease in the pulmonary venous to LA pressure gradient). The result is a characteristic inspiratory bulge or “bounce” of the interventricular septum into the LV. It should be recognized that an inspiratory septal bulge or “bounce” is not specific for cardiac tamponade but may be seen in other conditions associated with pulsus paradoxus, such as chronic obstructive pulmonary disease and pulmonary embolism. In these instances, the clinical context and the absence of a pericardial effusion rule out cardiac tamponade as causal. On the other hand, an inspiratory septal bulge may be absent in cardiac tamponade when there is LV hypertrophy or marked preexisting elevated LV filling pressures.27

Doppler Flow Velocity Recordings Analogous to the changes seen on M-mode and 2D echo, characteristic respiratory changes occur in pulsed


A

1443

B

Figs 68.8A and B: Pulsed wave Doppler in a patient with cardiac tamponade. Note the increased expiratory flow velocity of the mitral valve (A) and increased inspiratory flow velocity of the tricuspid valve (B).

Fig. 68.9: Hepatic vein flow reversals (arrow) during expiration. Note systolic forward venous flow predominates in moderatesevere tamponade with systolic inspiratory augmentation (*).

wave Doppler transvalvular velocities when compared with normal controls and patients with asymptomatic effusions, namely tricuspid and pulmonary flow velocities increase with inspiration while simultaneously mitral and aortic valve flow velocities decrease. The changes are greatest on the first beat of inspiration and expiration (a point which helps differentiate the respiratory variation seen in obstructive lung disease). Respiratory variation in the isovolumic relaxation and ejection times are also seen28,29 (Figs 68.8A and B). Normal hepatic venous flow is biphasic, with systolic velocity greater than diastolic velocity, and reduced

forward velocity or small reversals at atrial contraction and end systole (venous reversals); with inspiration, both peak systolic and diastolic flow velocities increase. In mild cardiac tamponade, forward flow velocities decrease and venous flow during systole predominates because intrapericardial pressure decreases significantly only during ventricular ejection. In moderate tamponade, diastolic flow velocity is markedly reduced but still augments with inspiration. When tamponade is severe, forward flow occurs only during systole, and when hepatic forward flow is observed only during inspiration, systemic venous and intracardiac pressures are markedly elevated and equalized at which time cardiac arrest is imminent (Fig. 68.9). Patients with cardiac tamponade also display characteristic expiratory changes of hepatic venous flows. On the first beat of expiration, diastolic flow velocity decreases or reverses. High positive and negative predictive values for cardiac tamponade are reported using hepatic venous recordings (82% and 88%, respectively), but they are not evaluable in about one-third of patients.24

Echo-Guided Pericardiocentesis Unless the situation is immediately life-threatening, experienced staff should perform pericardiocentesis in a facility equipped with monitoring to optimize the success and safety of the procedure. Monitoring the cardiac rhythm and systemic blood pressure is a minimum requirement. The advantages of needle pericardiocentesis include the ability to perform careful hemodynamic measurements

1444


A

B

Figs 68.10A and B: Two-dimensional (2D) echocardiography-assisted pericardiocentesis from the apical four-chamber view. Note the appearance of agitated saline bubbles (Figure A arrow) after successful needle entry into the pericardial space. Catheter advancement (Figure B arrow) is visualized as the pericardial drain is passed into the effusion. (LV: Left ventricle; RV: Right ventricle).

and relatively simple logistic and personnel requirements. The safety of the procedure has been increased by using 2D echo guidance with a 1.2% major complication rate in 1,127 cases over 21 years.30 Echocardiographic guidance assists pericardial drainage using alternative sites on the chest wall. Injection of agitated saline and imaging can confirm that the pericardial space was entered (Figs 68.10A and B).

CONSTRICTIVE PERICARDITIS Constrictive pericarditis (CP) is a condition in which a thickened, scarred, inelastic, noncompliant, and often calcified pericardium limits diastolic filling of the ventricles. The etiologies of CP are wide-ranging and include viral and idiopathic pericarditis, cardiac surgery (the most common antecedent in developed countries), tuberculosis (common in underdeveloped countries), collagen vascular disease, trauma, and chest radiation. CP may have a long latency period after the initial (and sometimes unrecognized) pericardial injury as might occur in post-irradiation and post-traumatic pericarditis, becoming apparent only decades later. Although it is commonly thought that a normal pericardial thickness excludes the diagnosis of CP, 28% of 143 surgically confirmed cases had normal pericardial thickness on CT scan, and 18% had normal thickness on histopathological examination.31 Classic chronic CP is encountered less frequently than it was in the past, whereas subacute CP, occurring weeks to months after the inciting injury, is becoming

more common. Postoperative CP is an important cause of constriction, with a reported incidence of 0.2%.8 Transient (acute) constriction may occur in approximately 15% of patients with acute effusive pericarditis. Doppler-detected constrictive physiology resolved without pericardiectomy in 36 of 212 patients studied retrospectively after an average of approximately 8 weeks at Mayo Clinic.32 The most common cause of transient CP was caused by pericardial inflammation after pericardiotomy in nine cases; infection, idiopathic, collagen vascular disease, trauma, and malignancy accounted for the remaining cases. Treatment included anti-inflammatory agents, antibiotics, chemotherapy, and angiotensin-converting enzyme inhibitors plus diuretics. Five patients had resolution of constriction without any specific therapy. Localized CP is rare, but occasionally a localized band constricts the inflow or outflow region of one or more of the cardiac chambers. The clinical picture then simulates valve disease or venous obstruction. The suspicion for CP is based on clinical history and examination, which require subsequent evaluation and confirmation by imaging and hemodynamic data. Most patients with CP are referred to evaluate cardiac function, right heart failure, ascites, or edema. Typical 2D and Doppler echo findings often arrive at the correct diagnosis and serve to differentiate CP from restrictive cardiomyopathy and other conditions (e.g. severe tricuspid regurgitation, chronic liver disease) mimicking constriction.


1445

Table 68.4: Echocardiographic Findings in Constrictive Pericarditis

M-Mode: •

Thickened pericardium (dual pericardial echos)

•

Septal shudder and bounce

• Atrial septal notch (immediately after atrial systole) • Flattening of the posterior left ventricle (LV) wall in mid-late diastole • Premature opening of the pulmonic valve Two-dimensional (2D) echo: •

Increased pericardial thickness (best with transesophageal echo)

• Septal shudder and bounce • Tubular appearance to ventricles with dilated atria •

D’Cruz sign [abnormal angle formed by LV and left atrium (LA) posterior walls]

• Vena caval plethora • Sharp diastolic filling halt

Fig. 68.11: M-mode echocardiogram from a patient with constrictive pericarditis. Note the echo-bright thickened posterior pericardium and flat posterior left ventricular (LV) wall during mid to late diastole (arrow). An atrial systolic notch (*) is visualized after atrial systole.

Doppler: • Restrictive diastolic filling pattern on mitral and tricuspid inflow • E/A velocity ratio > 1.5 with shortened deceleration time (< 150 ms) • Tricuspid inflow velocity increases on first beat after inspiration •

Mitral inflow velocity decreases on first beat after inspiration

• Expiratory increase in pulmonary vein velocities • Diastolic hepatic vein expiratory reversals •

Increased mitral propagation velocity (color M-mode)

Tissue Doppler: •

Elevated e' velocity

• Annulus paradoxus • Annulus reversus

M-Mode and Two-Dimensional Echo Echo is usually the initial diagnostic procedure in patients with suspected CP (Table 68.4). Pericardial thickening and calcification, and abnormal ventricular filling produce characteristic changes on the M-mode echo. Increased pericardial thickness is suggested by parallel motion of the visceral and parietal pericardium, which is separated by a relatively echo-free space. Echocardiographic correlates of the hemodynamic abnormalities of CP include diastolic

flattening of the LV posterior wall endocardium, abrupt posterior motion of the ventricular septum in early diastole with inspiration (septal shudder and bounce), and occasionally, premature opening of the pulmonary valve. These findings, which reflect abnormal filling of the ventricles, are insensitive and subtle and lack the specificity to be clinically useful. Although no sign or combination of signs on M-mode echocardiography is diagnostic of CP, a normal study virtually rules out the diagnosis33 (Fig. 68.11). Two-dimensional echocardiography echo reveals dilation and absent or diminished collapse of the IVC and hepatic veins indicative of elevated RA pressure, moderate biatrial enlargement, a sharp halt in ventricular diastolic filling, and abnormal ventricular septal motion that results from interventricular dependence (Movie clip 3). LV systolic function as judged by the ejection fraction is typically normal but may be impaired in mixed constrictive–restrictive disease, which may occur with radiation-induced disease or after cardiac surgery. Measurement of pericardial thickness by TEE correlates strongly with that obtained by CT and has deserved an ACC/AHA/ASE Class IIb recommendation.34 However, it is important to remember that demonstration of the characteristic “constrictive” hemodynamics is required to establish a firm diagnosis (Figs 68.12A and B).

1446


A

B

Figs 68.12A and B: Two-dimensional (2D) echocardiography findings in a patient with constrictive pericarditis. Note the tubular geometry of left ventricle in parasternal long-axis (A) and apical four-chamber (B) views. Figure A demonstrates D’Cruz sign, an abnormal contour of the posterior left ventricle and posterior left atrial walls giving rise to an angle < 150°. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Doppler Flow Velocity Recordings Doppler echo is essential for diagnosis and usually shows restrictive LV and RV diastolic filling patterns, which are characterized by high early (E) velocity, shortened deceleration time (< 150 ms), and a reduced atrial (A) wave. Mitral inflow velocity usually, but not always, falls as much as 25–40% and tricuspid velocity greatly increases in the first beat after inspiration35,36 (Fig. 68.13). These respiration-induced phenomena are manifestations of enhanced ventricular interaction and are not present in either normal subjects or patients with restrictive cardiomyopathy. Increased respiratory variation of mitral inflow may be missing in patients with markedly elevated left atrial pressure but can sometimes be brought out in such patients by preload reduction with a head-up tilt or diuretic administration.37 Similar to mitral flow, the respiratory variation in pulmonary venous (particularly diastolic) flow is often pronounced. Hepatic vein diastolic flow reversal increases with expiration, reflecting the ventricular interaction and the dissociation of intracardiac and intrathoracic pressures, which is essential in the diagnosis of constriction38,39 (Fig. 68.14). In contrast, inspiratory hepatic vein diastolic flow reversals suggest restrictive cardiomyopathy. The propagation velocity of early diastolic transmitral flow on color M-mode is normal or increased and is often >100 cm/s.

Fig. 68.13: Transvalvular Doppler flow of the mitral valve in a patient with constrictive pericarditis. Mitral early inflow velocity falls by 40% in the first cardiac cycle after inspiration (arrow). There is inversely, a simultaneous increase in tricuspid inflow velocity (not shown).

Tissue Doppler imaging is particularly useful in differentiating between CP and restrictive cardiomyopathy.40–43 Tissue Doppler shows a prominent early diastolic velocity (e') from the medial mitral annulus, whereas the transmitral E is tall and narrow but the tissue e' is reduced (< 7 cm/s) in restrictive cardiomyopathy. The usually positive linear relation between E/e' and left atrial pressure is reversed in many patients with CP since


1447

Fig. 68.14: Doppler echocardiography of the hepatic vein in a patient with constrictive pericarditis. Hepatic vein diastolic flow reversal increases with expiration (arrows), due to ventricular interaction and the dissociation of intracardiac and intrathoracic pressures.

A

B

Figs 68.15A and B: Tissue Doppler velocities in a patient with constrictive pericarditis. There are normal lateral (A) and supranormal septal (B) early diastolic tissue velocities. Note the “annulus reversus” sign with higher septal than lateral early diastolic velocity. This sign is likely due to tethering of the lateral atrioventricular groove to the thickened pericardium.

medial e' increases progressively as the severity of constriction becomes worse; this has been called “annulus paradoxus”.44 In addition, lateral mitral annulus e’ is usually lower than e' from the medial annulus in patients with CP; this “annulus reversus” is thought to be due to the tethering of the lateral atrioventricular groove to the thickened pericardium45 (Figs 68.15A and B). Differences in longitudinal and circumferential deformation may distinguish CP from restrictive cardiomyopathy. Thus, circumferential strain, torsion, and early diastolic untwisting are reduced, and longitudinal strain, displacement, and early diastolic tissue velocities are unchanged in constriction, whereas circumferential strain and early diastolic untwisting

are preserved and longitudinal mechanics are reduced in restrictive cardiomyopathy. However, there could be reduced regional longitudinal mechanics in CP due to tethering of the involved pericardium.46 In those situations where echo findings are equivocal, additional imaging testing (CT or MR) is needed to make the diagnosis with greater confidence. In some patients, hemodynamic cardiac catheterization may be necessary to establish the diagnosis. Even when the diagnosis of CP is certain after an echo, other imaging tests are often necessary to evaluate pericardial inflammation, coexisting myocardial disease, or comprehensive pericardial as well as cardiovascular anatomy for subsequent management decisions.47

1448


A

B

Figs 68.16A and B: Two-dimensional (2D) echocardiogram (A) and M-mode of effusive constrictive pericarditis from the parasternal view. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

EFFUSIVE-CONSTRICTIVE PERICARDITIS Effusive–CP is an uncommon syndrome of pericardial constraint with clinical and pathophysiological features of both cardiac tamponade and chronic CP. Idiopathic pericarditis, radiation, and neoplasia are the most frequent antecedents. Unlike the predominant parietal involvement in chronic CP, involvement of the visceral as well as the parietal pericardium (epicarditis) is involved in effusive–CP with inflammation, fibrotic thickening, and variable degrees of myocardial adherence.48 In a series of 190 patients undergoing pericardiocentesis for cardiac tamponade, the disorder was diagnosed in 15 (8%).49 The diagnosis was defined by a failure of the right atrial pressure to fall by 50% or to a level below 10 mm Hg after pericardiocentesis. In these patients, constriction was clinically suspect in 7; symptoms were usually present for less than 3 months, right-heart failure was evident in all, evidence of acute pericarditis was noted in 7, pulsus paradoxus was noted in 10, and pericardial calcification was present in none. Noninvasive imaging is not very useful in the diagnosis of effusive–CP.50 The echo findings of effusive–CP depend on the stage of the disease, although most often the M-mode, 2D, and Doppler features are consistent with a moderate or large pericardial effusion and cardiac tamponade. The pericardial effusion may become organized; echogenic and fibrinous strands may result in regions of loculation (Figs 68.16A and B).

Metastatic neoplasia is the leading cause of pericardial disease in hospitalized patients, most often in patients with lung or breast cancer, melanoma, lymphoma, and acute leukemia. Many cases are asymptomatic and are found only incidentally at autopsy, but others cause symptoms and may progress to cardiac tamponade. Primary cardiac tumors may invade the pericardium directly51,52 (Figs 68.17A and B). Primary mesothelioma of the pericardium is a rare and highly lethal tumor. Signs and symptoms are nonspecific, and echocardiography is insensitive for its detection; CT and magnetic resonance imaging (MRI) are the most promising diagnostic tests. Other primary tumors of the pericardium are quite rare. Pericardial tumors may appear as nodular echodensities or diffuse pericardial thickening, the latter more common with malignant tumors. They are usually nonmobile although they may contain mobile elements. Benign lesions (teratomas, hemangiomas, and lymphangiomas) can appear as cystic masses with septations. The pericardium may be thickened and cause constriction; less commonly, effusive– CP occurs. Echocardiography rapidly and accurately detects pericardial effusion, identifies metastatic lesions, and provides evidence for cardiac compression. Delayedenhancement contrast MRI is particularly useful in evaluating pericardial mass lesions.

CONGENITAL ANOMALIES Pericardial cysts are usually rare remnants of defective embryological development of the pericardium. In


A

1449

B

Figs 68.17A and B: A pericardial metastasis near the right ventricle (A) is seen in patient with widely metastatic lymphoma in the subcostal window. Definity contrast enhancement (B) opacifies the right ventricle (RV) blood pool. (L: Liver).

A

B

Figs 68.18A and B: A pericardial cyst (arrow) is seen adjacent to the right ventricle. Color Doppler flow (B) within the right atrium demonstrates normal vena caval flow but a lack of flow within the pericardial cyst. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

contrast, hydatid cysts are infectious in nature. Cysts vary greatly in size and are most commonly found in the right cardiophrenic angle. Cysts are benign and produce no local or general symptoms; their importance lies in differentiation from neoplasm. Although they can be demonstrated echocardiographically as echolucent spaces that do not communicate with the pericardial sac on echocardiography, the nature of the lesion usually is confirmed by CT (Figs 68.18A and B). Pericardial diverticula are very rare and can be congenital or acquired malformations found most often at the costophrenic angles. Unlike pericardial cysts,

pericardial diverticula may communicate with the pericardial space and change in size depending on body position and respiration. Congenital absence of the pericardium is a rare condition that may be isolated or associated with other cardiac and noncardiac abnormalities, and pericardium may be completely or partially absent. Complete absence of the left pericardium is the most common variant. Echocardiographic and Doppler features of congenital absence of the pericardium include unusual imaging windows, enlargement of the RV, excessive cardiac motion, and abnormal motion of the interventricular septum.53

1450


Fig. 68.19: MRI-delayed enhancement sequence with gadolinium contrast demonstrates a diffusely enhancing (arrows), thickened pericardium.

MULTIMODALITY IMAGING OF THE PERICARDIUM Although echo remains as usually the initial imaging test for pericardial disorders because of its ease of use, wide availability, bedside availability, cost-effectiveness, and versatility, additional imaging modalities may be necessary. In general, CMR provides excellent anatomical, tissue characteristics and some physiological data. Compared to echo, CMR provides superior anatomical assessment with better spatial resolution and a larger field of view, but physiological assessment is more limited. Specifically, CMR provides diagnostic identification of pericardial edema from short tau inversion [T2 double inversion recovery (DIR) sequence or short inversion time inversion recovery (STIR) sequence] and inflammation from late gadolinium enhancement (LGE) sequences, which are not available with other imaging modalities54 (Fig. 68.19) Cardiac CT is a predominantly anatomical modality with superior definition of pericardial anatomy relative to surrounding chest structures and pericardial calcification. It is, therefore, used in situations where anatomy is incompletely defined by echo or a contraindication for CMR—for example, in a patient with suspected absence of the pericardium or a patient with a pacemaker. CT may also be useful for preoperative planning once pericardectomy is indicated especially in patients with a previous sternotomy.47 See Movie clips 1–3 under Chapter 68 in DVD.

REFERENCES 1. Shabetai R. The Pericardium. 2nd ed. Norwell, MA: Kluwer Academic; 2003: 1–29.

2. Edler I, Gustafson A, Karlefors T, et al. Ultrasound cardiography. Acta Med Scand. 1961;370:68–74. 3. Feigenbaum H. Echocardiographic diagnosis of pericardial effusion. Am J Cardiol. 1970;26(5):475–9. 4. Wann S, Passen E. Echocardiography in pericardial disease. J Am Soc Echocardiogr. 2008;21(1):7–13. 5. Little WC, Freeman GL. Pericardial disease. Circulation. 2006;113(12):1622–32. 6. Spodick DH. Macrophysiology, microphysiology, and anatomy of the pericardium: a synopsis. Am Heart J. 1992;124(4):1046–51. 7. Hoit BD, Lew WY, LeWinter M. Regional variation in pericardial contract pressure in the canine ventricle. Am J Physiol. 1988;255:H1370–1377. 8. Hoit BD. Diseases of the Pericardium. In: Fuster V, Walsh RA, editors. Hurst’s The Heart. 13th ed. New York: McGrawHill; 2011: 1917–39. 9. Lange RA, Hillis LD. Clinical practice. Acute pericarditis. N Engl J Med. 2004;351(21):2195–202. 10. Imazio M, Cecchi E, Demichelis B, et al. Indicators of poor prognosis of acute pericarditis. Circulation. 2007;115(21):2739–44. 11. Cheitlin, MD, Armstrong, WF, Aurigemma, GP, et al. ACC/AHA/ASE 2003 guideline for the clinical application of echocardiography. Available at: www.acc.org/ qualityandscience/clinical/statements.htm. Accessed February 2013. 12. Weitzman LB, Tinker WP, Kronzon I, et al. The incidence and natural history of pericardial effusion after cardiac surgery–an echocardiographic study. Circulation. 1984; 69(3):506–11. 13. Kuvin JT, Harati NA, Pandian NG, et al. Postoperative cardiac tamponade in the modern surgical era. Ann Thorac Surg. 2002;74(4):1148–53. 14. Sagristà-Sauleda J, Mercé J, Permanyer-Miralda G, et al. Clinical clues to the causes of large pericardial effusions. Am J Med. 2000;109(2):95–101. 15. Haaz WS, Mintz GS, Kotler MN, et al. Two dimensional echocardiographic recognition of the descending thoracic aorta: value in differentiating pericardial from pleural effusions. Am J Cardiol. 1980;46(5):739–43. 16. Mahabadi AA, Massaro JM, Rosito GA, et al. Association of pericardial fat, intrathoracic fat, and visceral abdominal fat with cardiovascular disease burden: the Framingham Heart Study. Eur Heart J. 2009;30(7):8506. 17. Sagristà-Sauleda J, Angel J, Sambola A, et al. Low-pressure cardiac tamponade: clinical and hemodynamic profile. Circulation. 2006;114(9):945–52. 18. Di Segni E, Feinberg MS, Sheinowitz M, et al. Left ventricular pseudohypertrophy in cardiac tamponade: an echocardiographic study in a canine model. J Am Coll Cardiol. 1993;21(5):1286–94. 19. Himelman RB, Kircher B, Rockey DC, et al. Inferior vena cava plethora with blunted respiratory response: a sensitive echocardiographic sign of cardiac tamponade. J Am Coll Cardiol. 1988;12(6):1470–7. 20. Singh S, Wann LS, Klopfenstein HS, et al. Usefulness of right ventricular diastolic collapse in diagnosing cardiac tamponade and comparison to pulsus paradoxus. Am J Cardiol. 1986;57(8):652–6.


21. Gillam LD, Guyer DE, Gibson TC, et al. Hydrodynamic compression of the right atrium: a new echocardiographic sign of cardiac tamponade. Circulation. 1983;68(2):294–301. 22. Schiller NB, Botvinick EH. Right ventricular compression as a sign of cardiac tamponade: an analysis of echocardiographic ventricular dimensions and their clinical implications. Circulation. 1977;56(5):774–9. 23. Rifkin RD, Pandian NG, Funai JT. Sensitivity of right atrial collapse and right ventricular diastolic collapse in the diagnosis of graded cardiac tamponade. Am J Noninvasive Cardiol. 1987;1:73–80. 24. Mercé J, Sagristà-Sauleda J, Permanyer-Miralda G, et al. Correlation between clinical and Doppler echocardiographic findings in patients with moderate and large pericardial effusion: implications for the diagnosis of cardiac tamponade. Am Heart J. 1999;138(4 Pt 1):759–64. 25. Hoit BD, Gabel M, Fowler NO. Cardiac tamponade in left ventricular dysfunction. Circulation. 1990;82(4):1370–6. 26. Hoit BD, Fowler NO. Influence of acute right ventricular dysfunction on cardiac tamponade. J Am Coll Cardiol. 1991;18(7):1787–93. 27. Hoit BD, Shaw D. The paradoxical pulse in tamponade: mechanisms and echocardiographic correlates. Echocardiography. 1994;11(5):477–87. 28. Leeman DE, Levine MJ, Come PC. Doppler echocardiography in cardiac tamponade: exaggerated respiratory variation in transvalvular blood flow velocity integrals. J Am Coll Cardiol. 1988;11(3):572–8. 29. Appleton CP, Hatle LK, Popp RL. Cardiac tamponade and pericardial effusion: respiratory variation in transvalvular flow velocities studied by Doppler echocardiography. J Am Coll Cardiol. 1988;11(5):1020–30. 30. Tsang TS, Enriquez-Sarano M, Freeman WK, et al. Consecutive 1127 therapeutic echocardiographically guided pericardiocenteses: clinical profile, practice patterns, and outcomes spanning 21 years. Mayo Clin Proc. 2002;77(5):429–36. 31. Talreja DR, Edwards WD, Danielson GK, et al. Constrictive pericarditis in 26 patients with histologically normal pericardial thickness. Circulation. 2003;108(15):1852–7. 32. Haley JH, Tajik AJ, Danielson GK, et al. Transient constrictive pericarditis: causes and natural history. J Am Coll Cardiol. 2004;43(2):271–5. 33. Engel PJ, Fowler NO, Tei CW, et al. M-mode echocardiography in constrictive pericarditis. J Am Coll Cardiol. 1985;6(2):471–4. 34. Ling LH, Oh JK, Tei C, et al. Pericardial thickness measured with transesophageal echocardiography: feasibility and potential clinical usefulness. J Am Coll Cardiol. 1997; 29(6):1317–23. 35. Hatle LK, Appleton CP, Popp RL. Differentiation of constrictive pericarditis and restrictive cardiomyopathy by Doppler echocardiography. Circulation. 1989;79(2): 357–70. 36. Oh JK, Hatle LK, Seward JB, et al. Diagnostic role of Doppler echocardiography in constrictive pericarditis. J Am Coll Cardiol. 1994;23(1):154–62. 37. Oh JK, Tajik AJ, Appleton CP, et al. Preload reduction to unmask the characteristic Doppler features of constrictive pericarditis. A new observation. Circulation. 1997;95(4): 796–9.

1451

38. Klein AL, Cohen GI, Pietrolungo JF, et al. Differentiation of constrictive pericarditis from restrictive cardiomyopathy by Doppler transesophageal echocardiographic measurements of respiratory variations in pulmonary venous flow. J Am Coll Cardiol. 1993;22(7):1935–43. 39. Sun JP, Abdalla IA, Yang XS, et al. Respiratory variation of mitral and pulmonary venous Doppler flow velocities in constrictive pericarditis before and after pericardiectomy. J Am Soc Echocardiogr. 2001;14(11):1119–26. 40. Garcia MJ, Rodriguez L, Ares M, et al. Differentiation of constrictive pericarditis from restrictive cardiomyopathy: assessment of left ventricular diastolic velocities in longitudinal axis by Doppler tissue imaging. J Am Coll Cardiol. 1996;27(1):108–14. 41. Ha JW, Ommen SR, Tajik AJ, et al. Differentiation of constrictive pericarditis from restrictive cardiomyopathy using mitral annular velocity by tissue Doppler echocardiography. Am J Cardiol. 2004;94(3):316–19. 42. Sohn DW, Kim YJ, Kim HS, et al. Unique features of early diastolic mitral annulus velocity in constrictive pericarditis. J Am Soc Echocardiogr. 2004;17(3):222–6. 43. Ha JW, Oh JK, Ommen SR, et al. Diagnostic value of mitral annular velocity for constrictive pericarditis in the absence of respiratory variation in mitral inflow velocity. J Am Soc Echocardiogr. 2002;15(12):1468–71. 44. Ha JW, Oh JK, Ling LH, et al. Annulus paradoxus: transmitral flow velocity to mitral annular velocity ratio is inversely proportional to pulmonary capillary wedge pressure in patients with constrictive pericarditis. Circulation. 2001; 104(9):976–8. 45. Veress G, Ling LH, Kim KH, et al. Mitral and tricuspid annular velocities before and after pericardiectomy in patients with constrictive pericarditis. Circ Cardiovasc Imaging. 2011;4(4):399–407. 46. Sengupta PP, Mohan JC, Mehta V, et al. Accuracy and pitfalls of early diastolic motion of the mitral annulus for diagnosing constrictive pericarditis by tissue Doppler imaging. Am J Cardiol. 2004;93(7):886–90. 47. Verhaert D, Gabriel RS, Johnston D, et al. The role of multimodality imaging in the management of pericardial disease. Circ Cardiovasc Imaging. 2010;3(3):333–43. 48. Dahiya A, Lytle BW, Klein AL. Constrictive epicarditis. J Am Coll Cardiol. 2011;58(6):e11. 49. Sagristà-Sauleda J, Angel J, Sánchez A, et al. Effusiveconstrictive pericarditis. N Engl J Med. 2004;350(5):469–75. 50. Hancock EW. A clearer view of effusive-constrictive pericarditis. N Engl J Med. 2004;350(5):435–7. 51. Wilkes JD, Fidias P, Vaickus L, et al. Malignancy-related pericardial effusion. 127 cases from the Roswell Park Cancer Institute. Cancer. 1995;76(8):1377–87. 52. Luk A, Ahn E, Vaideeswar P, et al. Pericardial tumors. Semin Diagn Pathol. 2008;25(1):47–53. 53. Connolly HM, Click RL, Schattenberg TT, et al. Congenital absence of the pericardium: echocardiography as a diagnostic tool. J Am Soc Echocardiogr. 1995;8(1):87–92. 54. Bogaert J, Francone M. Cardiovascular magnetic resonance in pericardial diseases. J Cardiovasc Magn Reson. 2009; 11:14.

CHAPTER 69 Three-Dimensional Echocardiographic Assessment in Pericardial Disorders O Julian Booker, Navin C Nanda

Snapshot  Two-Dimensional Transthoracic Echocardiography

Versus Three-Dimensional Transthoracic Echocardiography in Pericardial Effusion  Two-Dimensional Transthoracic Echocardiography Versus Three-Dimensional Transthoracic Echocardiography in Constric on

INTRODUCTION The pericardium is a relatively avascular fibroserous sac. It is created by invagination of the heart within the serous pericardium and surrounded by the fibrous pericardium. The serous pericardium is composed of a single layer of mesothelial cells. The layer adherent to the fibrous pericardium is termed the parietal layer. The layer deep to the fibrous pericardium is called the visceral pericardium. Those portions of the visceral pericardium that are adherent to the myocardium are specifically called the epicardium. The fibrous pericardium is much sturdier than the serous pericardium but is still relatively thin (< 2 mm) and surrounds the heart and part of the great vessels.1 Between the serous layers, there is a potential space that contains 15 to 50 mL of fluid that serves as lubrication. Most of the fluid is located within the interventricular and atrioventricular grooves with a predilection for more dependent areas. The pericardium has a unique interaction with heart. The fibrous pericardium attaches to the diaphragm, anterior mediastinum, and sternum. The pericardium surrounds the proximal portions of the great vessels, which serve as additional anchor points. These attachments serve

 Two-Dimensional Transthoracic Echocardiography

Versus Three-Dimensional Transthoracic Echocardiography in Pericardial Masses

to fix the heart within the chest. The nature and position of the fibrous pericardium also make it an important barrier to infection. Pericardial constraint allows for greater isovolumic pressures at any given volume for both the left and the right ventricles. These benefits of constraint are curbed by the absence of the pericardium.2–4 Further possible roles of pericardial constraint include preventing acute increases in chamber volume as a response to elevations in filling pressures. It also helps modulate the physical and hydrodynamic interaction between the four cardiac chambers5,6 and creates ventricular interdependence.7,8 There are anatomical and hemodynamic consequences to pericardial disease. The cardiac chambers are physically connected within a confined space within the pericardium. There is also hydrodynamic interdependence related to blood flow. Changes in the filling dynamics of one chamber will impact the others. Tamponade and constriction are primarily hemodynamic entities resulting from abnormal pericardial constraint. Echocardiography, with its ability to not only evaluate structure but also hemodynamic assessment, is the cornerstone of the evaluation of pericardial disorders. The standard evaluation involves Doppler interrogation and two-dimensional (2D) imaging.

Chapter 69: Three-Dimensional Echocardiographic Assessment in Pericardial Disorders

Over the past decade, more powerful computer processors have resulted in larger quantities of data that can be processed quickly. Development of a full matrix array has evolved echocardiography from an approximately 5 mm slice to a nearly full volumetric acquisition of the heart and its immediately surrounding structures using a gated, multiple-beat acquisition. Three-dimensional (3D) technology provides the ability to manipulate and crop the data set in an almost infinite number of orientations and provides a more complete assessment of cardiac anatomy including the pericardium. With high-resolution images, the surfaces of the two layers can be viewed en face.9 This approach allows for a more complete structural assessment than two-dimensional transthoracic echocardiography (2D TTE) alone. Publications regarding three-dimensional transthoracic echocardiography (3D TTE) in the evaluation of pericardial disease have been limited. Three-dimensional echocardiography’s more complete anatomical visualization

1453

can help define potential structural abnormalities. Given the importance of echocardiography in the evaluation of pericardial diseases, the potential incremental benefit of additional 3D images cannot be overlooked. Some of the potential diagnostic advantages of 3D echocardiography can be seen in Table 69.1 and Figures 69.1 to 69.11.

TWO-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY VERSUS THREE-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY IN PERICARDIAL EFFUSION 2D TTE is a sensitive, but not very specific method of identifying pericardial effusion.10 On 2D and M-mode imaging, pericardial fluid will appear as a hypoechoic space with hyperechoic structures, the epicardium and pericardium, respectively, on either side. The planar

Table 69.1: Advantages of 3D TTE* in Evaluating Pericardial Diseases

• Anatomy of pericardial layers – Parietal and visceral layers can be visualized en-face – Identification of extent of fibrin deposits, exudative coating over pericardial layers – Better visualization of fibrin strands—extension, attachments, mobility, and consistency • Pericardial effusion – Better identification of the echo reflectors within the fluid – Ability to comprehensively assess effusion behind the atria and right ventricle – More comprehensive identification of loculated effusions – Increased accuracy of size estimation • Pericardial hematomas – Easy identification and differentiation from uncomplicated effusion • Granulomatous disease – Ability to identify the central necrosis and hence the pathological characterization as granuloma – Ability to identify tethering of pericardium • Tumor/mass – More accurate identification of pericardial deposits – Provides clue to identification of malignant nature by identifying the inhomogeneous nature – Identification of extracardiac extension • Constrictive pericarditis – More comprehensive evaluation of extent and severity – Identification of morphological type Contd...

1454


Contd... • Differentiation of pericardial effusion from pleural effusion and ascites – En-face viewing of the falciform ligament to better identify ascites • Pericardiocentesis – Better needle visualization with its pyramidal imaging plane • Pericardial cyst – Identification of loculations and trabeculations *3D TTE, live/real time three-dimensional transthoracic echocardiography. Source: Reproduced with permission from Sudhakar S, Nanda NC. Role of live/real time three-dimensional transthoracic echocardiography in pericardial disease. Echocardiography. 2012;29:98–102.

A

B

C

D

Figs 69.1A to D: Live/real-time three-dimensional transthoracic echocardiography in pericardial effusion in a 64-year-old female with renal failure. (A) The arrowhead points to fibrin deposition over the right ventricular pericardium giving a rugged appearance. Pericardial effusion extends behind both atrial (see also Movie clip 69.1A). (B) Apical four-chamber view. Cropping from bottom displays a smooth visceral pericardium over the basal left atrial (LA) wall (arrowhead; see also Movie clip 69.1B). (C) Subcostal examination. Arrowheads show multiple fibrin deposits on the right atrial (RA) visceral pericardium resulting in a rugged appearance (see also Movie clip 69.1C). (D) Arrowhead shows a flap-like fibrin mass (see Movie clip 69.1D parts 1 and 2). (IVC: Inferior vena cava; LV: Lleft ventricle; PE: Pericardial effusion; TV: Tricuspid valve).6 Source: Reproduced with permission from Ref. 10.


1455

nature of standard 2D imaging can make distinguishing pericardial effusions from ascites or pleural effusion difficult. The falciform ligament, which appears as a linear band stretching from the liver to the abdominal wall, can be used to identify ascites. However, the linear nature of the ligament can make it difficult to distinguish from fibrinous strands that can sometimes be seen within the pericardial space. With 3D TTE, the falciform ligament more closely approximates its appearance in vivo and can be seen as a sheet-like structure (Fig. 69.2C). 2D TTE’s ability to delineate pleural effusion can be equally difficult. The parasternal long axis view is the most frequently used to identify pleural effusion. The oblique sinus represents the reflection of the pericardium. The

result is that pericardial effusions will be found anterior to the descending aorta. 3D TTE can be used better to identify the pericardial space in relation to the aorta. Similarly, visualization of atelectatic lung can help differentiate pleural and pericardial effusions (Fig. 69.3). 2D TTE’s ability to quantify pericardial effusions is unreliable. Estimation of pericardial volumes using the posterior free space11 does not adequately account for loculated effusions or asymmetry related to postural shifts. 3D TTE can acquire the entire pericardial space in a single acquisition. By identifying the visceral and parietal borders, pericardial fluid volumes can be quantified without geometric assumptions. 3D TTE has proven itself to be more accurate and reproducible than 2D TTE

A

B

C

Figs 69.2A to C: Live/real time three-dimensional transthoracic echocardiography in pericardial effusion in an 85-year-old female with congestive heart failure and ascites. (A) Upper and lower arrowheads point to visceral and parietal layers of the pericardium, respectively. Both the pericardial layers are smooth without fibrin deposition (see also Movie clip 69.2A); (B) Right parasternal examination. The arrowhead points to a smooth visceral pericardium overlying the right (RA) and left (LA) atrium (see also Movie clip 2B); (C) The arrowhead shows a localized collection of fibrin over the visceral pericardium of the left ventricular (LV) free wall (see also Movie clip 69.2C). Movie clip 69.2D shows pericardial effusion (arrowhead) extending behind the left atrium. The arrowhead in Movie clip 69.2E points to three-dimensional images of the falciform ligament which is a useful landmark in distinguishing ascites from associated pericardial effusion. It appears as a sheet of tissue connected to the liver rather than a linear echo mimicking a fibrin strand seen with conventional two-dimensional imaging. The arrowhead in Movie clip 69.2F points to the falciform ligament viewed en-face in another patient with ascites. (D: Diaphragm; DA: Descending thoracic aorta; IVC: Inferior vena cava; L: Liver; RV: Right ventricle). Source: Reproduced with permission from Ref. 10.

1456


Fig. 69.3: Live/real time three-dimensional transthoracic echocardiography in an 84-year-old male with renal failure, and pericardial and left pleural effusions. Cropping of the threedimensional data set using Qlab software analysis package revealed a rugged visceral (1, 2, arrowhead) and parietal (3) pericardium as well as a rugged visceral (4) and parietal (5) pleura, from fibrin deposits (see also Movie clip 69.3A). Movie clips 69.3B and C show similar findings using regular cropping in the same patient. Movie clips 69.3D and E are from a different patient with pleural effusion, shown for comparison. These show cropping to more comprehensively assess the extent of pleural effusion (PLE) and the collapsed lung (arrowhead) and their relation to the heart (H). Movie clip 69.3F from another patient with chronic renal failure shows the attachment of collapsed lung lobes (horizontal arrowheads) to the hilum (vertical arrowheads) and its relationship to the heart (H). This patient had previously undergone pericardiectomy for constriction. Both these patients were studied from the back in the sitting position. (DA: Descending thoracic aorta; PP: Parietal pericardium; VPL: Visceral pleura; VP: Visceral pericardium). Source: Reproduced with permission from Ref. 10.

in quantifying asymmetric pericardial effusions.12 The potential benefit for serial evaluations of effusion size cannot be overstated. 3D TTE has improved visualization of the inferior vena cava, right ventricle, and right atrium. Classic changes often found in tamponade such as a plethoric inferior vena cava diastolic collapse of the right ventricle as well as inappropriate collapse of the atria can be seen by both 2D and 3D TTE. However, these findings can be better appreciated on 3D TEE providing incremental benefit in the assessment of tamponade.13 Fibrin deposits have been documented in virtually every type of pericardial disease. Echogenic material seen within the pericardial space has been associated with worse clinical outcomes like recurrence of pericardial effusions and constrictive pericarditis.14,15 As such, identifying the presence of these strands becomes

Fig. 69.4: Live/real time three-dimensional transthoracic echocardiography in a 62-year-old male with pericardial effusion developing following mitral valve replacement. Arrowheads point to fibrinous strands connecting the visceral and parietal portions of the pericardium. The accompanying Movie clips 69.4A and B from the same patient show both mobile and nonmobile fibrin strands. In Movie clip 69.4A, artifacts appeared when the instrument gain was decreased and disappeared with increase in gain, emphasizing the importance of optimizing gain settings when assessing threedimensional images. Movie clip 69.4B shows cropping done using the Qlab software analysis package. Abbreviations as in previous figures. Source: Reproduced with permission from Ref. 10.

critically important in the evaluation of pericardial effusions. 3D TTE has shown to be superior to 2D TTE in identifying and characterizing the consistency, location, and mobility of fibrinous material within the pericardial space (Figs 69.1 and 69.4). Fibrin stranding and other echogenic pericardial materials are most often associated with inflammatory processes. 3D TTE’s ability to define these echo reflectors can help identify more complicated effusions such as hematomas and purulent effusions (Figs 69.5 and 69.6).9,16 Should pericardiocentesis be required, the 3D TTE provides superior anatomical delineation to guide pericardiocentesis.17

TWO-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY VERSUS THREE-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY IN CONSTRICTION Fibrinous adhesions are a result of the inflammatory process within the pericardial space. Fibrinous adhesions of the visceral and parietal pericardia can be found at the


1457

Fig. 69.5: Live/real time three-dimensional transthoracic echocardiography in a 50-year-old male status post cardiac transplantation and pericardial effusion compressing the right atrium. The arrowhead points to the compressed right atrium (RA). Cropping reveals no significant echo reflectors (“solid tissue”) in the effusion suggesting that it mainly comprises fluid or represents a hematoma that is of uniform, homogenous consistency (see also Movie clip 69.5). The patient improved after drainage of 1,000 cc of yellowish fluid from the pericardial cavity using a pigtail catheter. (Abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.

Fig. 69.6: Live/real time three-dimensional transthoracic echocardiography in a 17-year-old male with a bullet injury and subsequent development of pericardial hematoma. The red dots outline a loculated component of a very large pericardial hematoma (see also Movie clip 69.6A). Movie clip 69.6B shows a huge pericardial hematoma (arrowhead) with large multiple echolucencies consistent with fluid collections. These were not well seen on two-dimensional imaging. (Abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.

time of necropsy without any history of overt pericardial disease.18 Constrictive pericarditis is the condition where the parietal and/or visceral pericardium become thickened and sometimes calcified to the point where it inhibits filling of the cardiac chambers. Constrictive pericarditis is a difficult-to-diagnose condition. The primary diagnosis of constriction is made by hemodynamic assessment, either by echocardiography or simultaneous right and left heart catheterizations. Unfortunately, there are no good medical treatments for chronic constrictive pericarditis as the mechanism of the constrictive physiology is structural. Because pericardiectomy is difficult and associated with significant morbidity, it is paramount that the diagnosis is correct before proceeding. However, many clinicians prefer additional evidence in the form of imaging, such as thickening or calcification of the pericardium to support the diagnosis before committing the patient to surgery. Historically, the imaging modalities of choice for morphological assessment of the pericardium have been magnetic resonance imaging (MRI) or computed tomography scan (CT). They have been shown to

accurately delineate the thickness and calcification of the involved pericardium. Determining the extent of pericardial involvement by echocardiography can be unreliable with 2D imaging. 3D TTE has shown the ability to identify pericardial involvement along the entire extent of both ventricles.9,19 An excellent example can be found in a woman with recurrent heart failure symptoms. Her 2D TTE showed limited calcification of the posterior wall of the left ventricle and anterior free wall of the right ventricle. 3D TTE showed extensive involvement of the regions in question and was suggestive of a severe constrictive process (Fig. 69.11). These findings were corroborated with cardiac MRI and later confirmed at the time of surgery.10 Similar to MRI, 3D echocardiography can demonstrate tethering of the affected pericardium to the adjacent myocardium. These characteristics of 3D TTE may make it an ideal third option for morphological assessment of pericardium in surgical planning. The fact that the 3D imaging can be acquired at the time of the standard 2D echocardiographic evaluation of constriction may someday make 3D TTE the preferred choice over MRI and CT.

1458


Perhaps the greatest benefit of 3D TTE over 2D TTE in the evaluation of pericardial disease lies in the evaluation of

mass lesions. Manipulation of the 3D data set allows a more complete visualization of pericardial-based masses. Systematic cropping can provide information about the character of a mass. Identifying inhomogeneity within a mass can provide clues to its nature. Conversely, an echolucent lesion without flow on Doppler is likely to be a benign pericardial cyst (Fig. 69.10). 3D TTE has been used successfully in a case series to provide vital clues as to the pathology of several

A

B

C

D

TWO-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY VERSUS THREE-DIMENSIONAL TRANSTHORACIC ECHOCARDIOGRAPHY IN PERICARDIAL MASSES

Figs 69.7A to D: Live/real time three-dimensional transthoracic echocardiography in a 26-year-old male with tuberculous pericardial effusion. (A) Cropping of the apical four-chamber data set shows no inward motion of the proximal right ventricular free wall (arrowhead) during systole, probably due to fibrinous adhesions. The distal wall contracts well; (B) Examination of visceral pericardium (VP) over the ventricles demonstrates a mildly rugged appearance. Movie clips 69.7A and B Parts 1 to 3 show the cropping technique used to demonstrate the visceral pericardium of both ventricles; (C) A large mass (arrowhead) is seen involving the visceral pericardium of the left ventricle (LV). The etiology is not clear but it could possibly represent a tuberculous granuloma; (D) The arrowhead points to a large highly echogenic mass involving the right ventricular visceral pericardium consistent with a calcified granuloma in another patient with tuberculosis. Movie clip 69.7C from the same patient shows a granuloma (arrowhead) involving the parietal pericardium. Movie clips 69.7D and E are from a different patient with purulent pericardial effusion due to methicillin-resistant Staphylococcus aureus. Movie clip 69.7D shows markedly thickened and echogenic parietal (upper arrowhead) and visceral (lower arrowhead) pericardium. Movie clip 69.7E shows an abnormal loculated appearance of the visceral pericardium (arrowhead) when viewed en-face by cropping from the apex. (Abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.


A

1459

B

Figs 69.8A and B: Live/real time three-dimensional transthoracic echocardiography in a 66-year-old male with pericardial metastasis from a malignant thymoma. (A) The arrowhead shows a huge pericardial mass (bounded by red dots) measuring 9.2 × 6.3 cm. Movie clips 69.8A to C show the full extent of this huge mass with three-dimensional imaging. Cutting open the tumor in its mid portion (arrowhead in Movie clip 69.8B) revealed solid inhomogenous tissue. Arrowheads in Movie clip 69.8C show parietal involvement of the tumor by multiple band-like extensions. The two-dimensional study in this patient (Movie clip 69.8D) shows a much smaller mass (arrowhead) measuring 3.8 × 1.5 cm attached to the right ventricular outflow tract visceral pericardium; (B) Surgical specimen. (Other abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.

A

B

Figs 69.9A and B: Live/real time three-dimensional transthoracic echocardiography in a 68-year-old male with lung carcinoma. (A and B) The arrowhead points to an irregular mass in the parietal pericardium (see also Movie clips 69.9A and B). The etiology is not clear, but it could possibly represent a pericardial metastasis. Movie clip 69.9C shows another mass (arrowhead) located over the visceral pericardium (VP) in this patient. This type of mass (arrowhead) was also seen by two-dimensional imaging (Movie clip 69.9D). However, the other mass seen involving parietal pericardium (PP) was not detected by this modality. Movie clip 69.9E is from a different patient with a poorly differentiated lung adenocarcinoma. Arrowhead points to a mass in the parietal pericardium consistent with metastasis. This was not visualized on two-dimensional imaging. Examination of pericardial fluid in this patient showed the presence of malignant cells. (Other abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.

masses. In one case, the echolucent core was suggestive of granuloma in a patient with confirmed tuberculosis (Fig. 69.7C). A second case of tuberculosis was found to have a highly echogenic pericardial mass consistent with

a calcified granuloma (Fig. 69.7D). The utility of 3D TTE is never more apparent than when evaluating masses in the setting of metastatic disease. In a patient with a known thymoma, a 3.8- × 1.5-cm was found to be adherent to the

1460

A


B

Figs 69.10A and B: Live/real time three-dimensional transthoracic echocardiography in a 36-year-old male with a pericardial cyst. (A) The arrowhead points to a pericardial cyst confirmed by a CT scan of the chest (see Movie clip 69.10A). (B) Cropping of the threedimensional data set demonstrates multiple band-like tissue (arrowhead) within the cyst (see Movie clip 69.10B). Movie clips 69.10C and D represent two-dimensional images which do not show multiple bands criss-crossing the cyst (arrowhead). (L: Liver). (Other abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.

A

B

C

Figs 69.11A to C: Two-dimensional and live/real time threedimensional transthoracic echocardiography in a 53-yearold female with constrictive pericarditis. (A) Two-dimensional study. Arrowheads in the parasternal long-axis view point to an echogenic left ventricular posterior wall consistent with calcification (see also Movie clip 69.11A); (B) Represents a threedimensional study using Qlab software analysis package. The arrow demonstrates a highly echogenic posterior pericardium consistent with calcification. When this was cropped transversely using an oblique cropping plane, widespread involvement of the left ventricular posterior wall with calcification (arrowhead) was evident. Highly echogenic calcification is visualized anteriorly also. Top and bottom arrowheads in the left upper quadrant in Movie clip 69.11B point to anterior and posterior calcification, respectively. The patient underwent pericardiectomy. (AO: Aorta; MV: Mitral valve). (Other abbreviations as in previous figures). Source: Reproduced with permission from Ref. 10.


visceral pericardium. 3D TTE later demonstrated that the mass was actually much larger, measuring 9.2 × 6.3 cm (Fig. 69.8). Moreover, the lesion was both solid and inhomogeneous, consistent with tumor. These dimensions correlated closely with the pathological specimen at the time of surgery.9

CONCLUSION Pericardial diseases vary widely in their nature and consequences. Although 2D TTE is the imaging modality of choice to evaluate pericardial conditions, its planar nature can lead to incomplete visualization of the pericardium. 3D TTE has shown benefit in both the diagnosis of pericardial disease and guiding therapeutic intervention. Including a 3D data set should become part of the routine echocardiographic evaluation of pericardial disease where the diagnosis is in question or if intervention is required.

REFERENCES 1. Choi HO, Song JM, Shim TS, et al. Prognostic value of initial echocardiographic features in patients with tuberculosis pericarditis. Korean Circ J. 2010;40(8):377–86. 2. Shabetai R, Mangiardi L, Bhargava V, et al. The pericardium and cardiac function. Prog Cardiovasc Dis. 1979;22: 107–34. 3. Fowler NO, Gabel M, Holmes JC. Hemodynamic effects of nitro-prusside and hydralazine in experimental cardiac tamponade. Circulation. 1978;57:563–7. 4. Glantz SA, Misbach GA, Moores WY, et al. The pericardium substantially affects the left ventricular diastolic pressurevolume relationship in the dog. Circ Res. 1978;42:433–41. 5. Maruyama Y, Ashikawa K, Isoyama S, et al. Mechanical interactions between four heart chambers with and without the pericardium in canine hearts. Circ Res. 1982;50: 86–100.

1461

6. Spodick DH. Threshold of pericardial constraint: the pericardial reserve volume and auxiliary pericardial functions. JACC. 1985;6(2):296–7. 7. Bove AA, Santamore WP. Ventricular interdependence. Prog Cardiovasc Dis. 1981;23:365–88. 8. Santamore WP, Shaffer T, Papa L. Theoretical model of ventricular interdependence: pericardial effects. Am J Physiol. 1990:259. 9. D’Cruz IA, Khouzam RN, Minderman D. Three-dimensional echocardiographic appearances of pericardial effusion with tamponade. Echocardiography. 2007;24(2):162–5. 10. Hernandez CM, Singh P, Hage FG, et al. Live/real time three dimensional transthoracic echocardiographic assessment of pericardial disease. Echocardiography. 2009;26:1250–63. 11. Horowitz MS, Schultz CS, Stinson EB, et al. Sensitivity and specificity of echocardiographic diagnosis of pericardial effusion. Circulation. 1974;50:239–47. 12. Hsu FL, keefe D, Desiderio D, et al. Echocardiographic and surgical correlation of pericardial effusion in patients with malignant disease. J Thoracic Cardiovasc Surgery. 1998:1215–16. 13. Kim SH, Song JM, Jung IH, et al. Initial echocardiographic characteristics of pericardial effusion determine the pericardial complications. Int J Cardiol. 2009;136(2):151–5. 14. Lee SH, Kim WH, Ko JK. Fibrinous pericardial effusion in a three-dimensional echocarcardiography. QJM. 2013. 15. Lewinter, M. Pericardial diseases. In: Libby, editor. Braunwald’s Heart Disease. Philadelphia: Saunders; 2008. 16. Nanda CN, Hsiung MC, Miller AP, et al. Live/Real Time 3D Echocardiography. Wiley-Blackwell, 2010. 17. Vazquez de Prada JA, Jiang L, Handschumacher MD, et al. Quantification of pericardial effusions by threedimensional echocardiography. J Am College Cardiol. 1994;24(1):254–9. 18. Waller BF, Taliercio CP, Howard J, et al. Morphologic aspects of pericardial heart disease; Part 1. Clin Cardiol. 1992;15(3):203–9. 19. Zagol B, Minderman D, Munir A, et al. Effusive constrictive pericarditis: 2D, 3D echocardiography and MRI imaging. Echocardiography. 2007;24:1110–14.

CHAPTER 70 Echocardiographic Assessment of Cardiac Tumors and Masses Leon Varjabedian, Jennifer K Lang, Abdallah Kamouh, Steven J Horn, Tuğba Kemaloğlu Öz, Aylin Sungur, Kruti Jayesh Mehta, Kunal Bhagatwala, Nidhi M Karia, Maximiliano German Amado Escañuela, Robert P Gatewood Jr, Navin C Nanda

Snapshot  Echocardiographic Assessment of Cardiac Tumors and Masses  Primary Benign Cardiac Tumors  Malignant Primary Cardiac Tumors

ECHOCARDIOGRAPHIC ASSESSMENT OF CARDIAC TUMORS AND MASSES Standard two-dimensional (2D) transthoracic echocardiography (TTE) with Doppler is the initial diagnostic modality of choice in a patient with a cardiac tumor or mass. Transesophageal echocardiography (TEE) is often complementary to TTE in the full assessment of patients with a known or suspected cardiac mass. A complete echocardiographic evaluation of a cardiac tumor or mass should include: (a) Characterization of the shape, dimensions, and volume of the mass (e.g. round vs lobulated, small vs large).1 The size of an intracardiac mass has important clinical implications in predicting embolic events, congestive heart failure, and death, and as an efficacy assessment after treatment (anticoagulation, antibiotics, and chemotherapy).2 Nanda et al. reported that 2D measurements from a transthoracic or a transesophageal study underestimate the true maximum diameter of irregularly shaped structures. (b) Identification of the location of the tumor and type of attachment to the heart (e.g. pedunculated vs sessile). (c) Description of the echogenicity (e.g. echolucent vs echodense, homogenous vs heterogeneous, and presence of calcification). (d) assessment of mobility (e.g.

 Secondary Cardiac Tumors  Normal Variants and Other Masses  MICE  Extracardiac Masses

sessile, prolapsing, shimmering). (e) Description of the relationship to adjacent structures (intra- or extracardiac). (f ) Identification of route of access to the heart [e.g. primary vs secondary through the wall, pulmonary veins, inferior vena cava (IVC)]. (g) Quantification of the hemodynamic consequences of the mass (e.g. flow or outflow tract obstruction, valvular stenosis or insufficiency, chamber filling or ventricular function). (h) Calculation of cardiac chamber dimensions, left ventricular volumes, and ejection fraction. The differential diagnosis of cardiac masses includes tumors, thrombi, nonbacterial thrombotic endocarditis, infective endocarditis, or normal variant intracardiac or extracardiac structures. Imaging features that favor a diagnosis of tumor are a mobile, pedunculated appearance and an associated pericardial effusion. Masses that cross anatomical planes, from myocardium to pericardium or endocardium, are likely to be tumors. The clinical setting and associated echocardiographic findings are also crucial in guiding the diagnosis of a cardiac mass. For example, left atrial thrombi are associated with mitral valve stenosis, enlarged left atrium, and atrial fibrillation, while ventricular thrombi are associated with cardiomyopathies or regional wall-motion abnormalities. Right atrial (RA) thrombi are seen in the setting of indwelling catheters or

Chapter 70: Echocardiographic Assessment of Cardiac Tumors and Masses

pacemaker wires. Nonbacterial thrombotic endocarditis is found in patients with malignancy or systemic lupus erythematosus. The sensitivities of transthoracic and Transesophageal echocardiogram for detection of a cardiac mass are 93% and 97%, respectively.3 In general, the sensitivity of both the TTE and TEE is highest for endocardial lesions because the mass is easily distinguished from the echolucent chamber, while the sensitivity is slightly lower for intramyocardial lesions and lowest for pericardial tumors. TTE offers a superior acoustic window for the left ventricle (LV) and, therefore, is more sensitive in detecting a left ventricular tumor. On the other hand, TEE has the advantage of providing better resolution for valvular and posterior structures that are distant from the anterior chest wall, such as the left and right atria, superior vena cava (SVC), and the descending thoracic aorta. Because of its superior image resolution and transesophageal approach, intraoperative TEE has proven extremely useful to the surgeon for the guidance of tumor resection, particularly in cardiac sarcoma. Increasingly, TEE is also used to aid cardiac biopsy and guide surgical intervention, helping to ensure that there is no residual tumor and that the repaired structures are free of defects. A concerning limitation of assessing cardiac masses with 2D echocardiography (2DE) is the possibility of actually “missing” the mass during the evaluation due to complex geometric shapes. This can sometimes be overcome by employing nonstandard views. Threedimensional echocardiography (3DE) has an important advantage over 2DE in its ability to show 3D structures rather than the need to conceptualize these complex shapes from multiple cross-sectional 2D images.4 3DE has an additional advantage in evaluating cardiac tumors because of its ability to locate the precise attachment of a mass to the myocardium, to section the mass and view it from any plane, to calculate the volume of a mass and follow this volume over time, and to accurately define the spatial relationship of the mass to other structures.2,5,6 Images obtained by 3DE can be sectioned and viewed from any angle, providing the examiner a more detailed assessment of the mass even from within. Certain masses have distinctive and characteristic appearances that can aid in making the diagnosis. For example, fibromas and lipomas typically are dense, very bright homogenous masses, which relate to the presence of fibrous tissue. Myxomas demonstrate localized areas of large echolucencies consistent with necrosis or hemorrhage

1463

as well as very bright reflective echodense areas with or without acoustic shadowing due to calcifications pointing to their chronicity.7 Hemangiomas are highly vascular tumors that demonstrate more extensive and closely packed vascular (echolucent) areas that extend all the way to the periphery with little solid tissue as compared to myxomas.8 High-grade sarcomas may demonstrate areas of necrosis with dilated vasculature (echolucencies) surrounded by dense hyperechoic band-like tissue consistent with fibrosis, thus giving the appearance of a “doughnut”.9 On 3DE, papillary fibroelastomas are characterized by a central echodensity that corresponds to their fibrocollagenous core and finger-like projections, which represent multiple fronds.10 The stalk by which this tumor attaches to the valve can also be well seen. They may be difficult to differentiate from Lambl’s excrescences, which are also attached to the tip of the valve leaflets. Lambl’s excrescences, however, usually present as multiple strands on multiple valves and tend not to be discreet rounded lesions. When TTE and TEE cannot provide definitive answers regarding the presence or absence of vegetations, a three-dimensional transthoracic echocardiography (3D TTE) might prove useful.11 3DE is particularly helpful in visualizing all three leaflets of the tricuspid valve, the right atrium, the right ventricle (RV), and any indwelling catheters to assess for the presence of vegetations. Three acquisition modes are used with real time 3D echocardiography (RT3DE) in the evaluation of cardiac tumors: (a) full volume, (b) live 3D, and (c) 3D zoom (a smaller, magnified pyramidal data at a higher resolution).12 Full-volume acquisitions can be obtained from the parasternal, apical four-chamber, apical two-chamber, and subcostal views. However, the availability of more data in these large pyramids of information comes at the expense of lower image resolution. Hence, imaging with narrow angles (live 3D) is recommended if highresolution images of the cardiac mass are desired. Fullvolume acquisition allows the echocardiographer to slice and crop the heart in as many ways as required to obtain a comprehensive tomographic evaluation of the mass. Fullvolume and live 3D acquisitions in the bicaval view are useful in characterizing masses in the SVC, IVC, interatrial septum, and right atrium.1 RT3DE provides a more comprehensive assessment of the interior structure of the mass that correlates better with pathological findings (necrosis, hemorrhage, cystic areas, or fibrotic bands).9,13 RT3DE can also enhance the ability of

1464


the echocardiographer to detect associated abnormalities and conditions that predispose to the development of a mass, such as an LV apical aneurysm or rheumatic mitral valve disease.14,15 It helps to characterize masses in the right atrium, where the differential diagnosis includes a normal structure (prominent IVC ridge or a crista terminalis), embryonic remnants (prominent Eustachian valve or a Chiari network), thrombus, or a tumor arising from the IVC.16,17 Therefore, full assessment of patients with a cardiac mass or tumor requires a comprehensive TTE that may need to be supplemented with TEE and or 3DE as well as cardiac computed tomography (CT) and magnetic resonance imaging (MRI). 3D TTE can assess the size of cardiac masses and describe the complex anatomy of the heart.18 If a cardiac lesion is identified, chest CT with contrast enhancement and cardiac magnetic resonance imaging (CMR) with contrast are superior modalities for characterization of the lesions and delineation of the extent of tumor involvement. They can also help exclude the possibility of direct cardiac extension of a tumor that originates from adjacent mediastinal structures. CT and CMR are particularly good at depicting the pericardium and great vessels and evaluating the extent of disease, and CT can also detect calcification, which is important in the differential diagnosis.19 Echocardiographic contrast agents can also help correctly classify intracardiac masses, differentiating tumors from thrombi.20 Tissue characterization of the mass with perfusion assessment can differentiate between a contrast hyperenhanced (highly vascular or malignant tumors), contrast hypoenhanced (with poor vascularity such as myxomas), or with no enhancement (such as avascular thrombi). Use of myocardial contrast has been recommended by American Society of Echocardiography Consensus statement to characterize masses.21 Other methods including MRI can be used as complementary techniques to evaluate intracardiac tumors.

majority of the remainder originating in the right atrium.22 Other less common locations are the ventricles (RV more than LV), valves [usually tricuspid valve (Figs 70.2A and B; Movie clip 70.2) more than mitral valve], and IVC.23,24 On gross examination, myxomas have a soft, gelatinous appearance with some lobulation.25 They may contain areas of hemorrhage (Figs 70.3 to 70.5; Movie clip 70.3)5 and calcification (Figs 70.6A to C) and generally range between 5 and 6 cm in dimension. Figure 70.6D explains why, unlike 3DE, the size of a cardiac mass including myxomas can be frequently underestimated by twodimensional TTE as well as multiplanar two-dimensional TEE. The classic triad of symptoms relates to the obstructive, embolic, and constitutional effects of the tumor.26,27 However, myxomas are often asymptomatic or associated with no specific symptoms or clinical findings (e.g. incidental findings of a murmur on physical examination). Myxomas have female gender preponderance. No significant difference exists between male and female patients’ age (32 ± 22.39 years, 43.75 ± 18.73 years, P = 0.1692).28 The most common origin of atrial myxoma is the interatrial septum (Figs 70.7A to F); Movie clips 70.7A and B) near the fossa ovalis, accounting for 85% of the cases.29 Other less common anatomical origins within the atria in descending order of frequency are posterior and anterior walls and the atrial appendage.30,31 Atrial myxoma tends to be larger in size (Figs 70.8A and B),32 thereby obstructing

PRIMARY BENIGN CARDIAC TUMORS Cardiac Myxoma Cardiac tumors are rare with an estimated incidence of 1/100,000 per year. Albeit myxoma being the most frequently encountered benign cardiac tumor. Myxomas commonly arise on the endocardial surface of all cardiac chambers and rarely the heart valves. Seventy-five percent of myxomas occur in the left atrium (Fig. 70.1), with the

Fig. 70.1: Transthoracic two-dimensional (2D) echocardiogram (apical four-chamber view) of a patient with a 5.0 × 5.6 cm spherical mass seen attached to the posterior roof of the left atrium representative of an atrial myxoma. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Dr Sachin Wadhawan, Buffalo Heart Group, Buffalo NY.


A

1465

B

Figs 70.2A and B: Transesophageal echocardiogram of a patient with a tricuspid valve myxoma. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clip 70.2.).

A

B

C

Figs 70.3A to C

1466


E

D

G

F

Figs 70.3A to G: Live/real time three-dimensional (3D) transthoracic echocardiographic assessment of left atrial myxoma. (A to C) Frontal plane sections taken at three different sequential levels in the 3D data set demonstrate echolucencies (arrowhead) within the tumor consistent with hemorrhage, which is largest in the middle section (B); (D) Transverse plane sections of the tumor viewed en face, also demonstrating hemorrhage (arrowhead); (E) Frontal plane, transverse plane, and vertical plane sections of the tumor showing extensive hemorrhage (arrowhead); (F) The arrow points to the tumor stalk; (G) Resected specimen showing a large hemorrhage. Arrows in the Movie clip 70.3 point to large areas of hemorrhage that correspond with the surgical specimen. (AO: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle) (Movie clip 70.3). Source: Reproduced with permission from Mehmood F, Nanda NC, Vengala S, et al. Live three-dimensional transthoracic echocardiographic assessment of left atrial tumors. Echocardiography. 2005;22(2):137–43.


A

1467

B

Figs 70.4A and B: Live/real time three-dimensional transthoracic echocardiographic assessment of left atrial myxoma. (A) Arrowhead points to a large echolucency consistent with a large hemorrhage. (B) Resected specimen showing a large hemorrhage. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Mehmood F, Nanda NC, Vengala S, et al. Live three-dimensional transthoracic echocardiographic assessment of left atrial tumors. Echocardiography. 2005;22(2):137–43.

A

B

Figs 70.5A and B: Live/real time three-dimensional transthoracic echocardiographic assessment of left atrial myxoma. (A) Arrowhead points to a large echolucency, which corresponds closely to the hemorrhage seen in the resected specimen (B). (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Mehmood F, Nanda NC, Vengala S, et al. Live three-dimensional transthoracic echocardiographic assessment of left atrial tumors. Echocardiography. 2005;22(2):137–43.

1468


A

B

C

D

Figs 70.6A to D: Two-dimensional (A) and live/real time three-dimensional (3D; B and C) transesophageal echocardiography. (A) Arrow points to a myxoma in the left atrium with a broad attachment on the atrial septum. The dense areas represent calcification, while the echolucent areas indicate the presence of hemorrhages. (B and C) The attachment of the tumor is much better delineated by the 3D technique. (IAS: Interatrial septum; LA: Left atrium; RA: Right atrium); (D) Schematic diagram demonstrating that the maximum dimension of an object (in this case, a cylinder) can be obtained only if the ultrasound beam cuts through its longest dimension (true long axis) when using a multiplane probe. However, when the two-dimensional planes (dotted lines) are stacked together to obtain a 3D image, the object (cylinder), including its long axis, can be viewed completely, even though it is not oriented parallel to the ultrasound beam as it is rotated from 0° to 180° (Movie clips 70.6A to C). Source: Reproduced with permission from Nanda NC et al. Incremental value of three-dimensional echocardiography over transesophageal multiplane two-dimensional echocardiography in qualitative and quantitative assessment of cardiac masses and defects. Echocardiography. 1995;12:619–28.

the valvular orifice. Myxomas originating from heart valves are uncommon and tend to be small in size.33 Atrial myxoma originating from the fossa ovalis protrude into the atrial cavity but remain attached to the septum by a stalk (Figs 70.9 and 70.10; Movie clip 70.9). This stalk can be short, allowing little motion, or long, therefore explaining the motion that can be seen on real

time 2DE. Some atrial myxomas can prolapse into the mitral or tricuspid valve orifice and even into the ventricle during diastole. Ventricular myxomas (Figs 70.11A to D; Movie clips 70.11A, C Parts 1 to 3, D and E;34 Figs 70.12A to D; Movie clips 70.12B–D)7 may originate on the ventricular free wall or interventricular septum and may be sessile or


A

B

C

D

E

F

1469

Figs 70.7A to F: Transesophageal echocardiogram of a patient with a large left atrial septal myxoma (A to F) causing significant mitral regurgitation (E and F). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clips 70.7A and B).

1470


A

B

Figs 70.8A and B: Two-dimensional transesophageal echocardiography in a patient with a large biatrial myxoma presenting for operation. (A) Arrowheads point to areas of calcification within the tumor. (B) Arrowheads point to areas of hemorrhage within the tumor. (AS: Atrial septum; AV: Aortic valve; H: Hemorrhage; LA: Left atrium; LVO: Left ventricular outflow tract; M1: Myxoma in right atrium; M2: Myxoma in left atrium; RA: Right atrium; RVO: Right ventricular outflow tract). Source: Reproduced with permission from Srivastava R, Hsiung MC, Fadel A, Nanda NC. Transesophageal echocardiographic demonstration of biatrial myxoma. Echocardiography. 2004;21(2):187–8.

A

B

Figs 70.9A and B: (A) Parasternal long-axis and (B) apical four-chamber views demonstrating a large right atrial myxoma attached to the atrial wall by a stalk prolapsing through the tricuspid valve into the right ventricle. (RA: Right atrium; RV: Right ventricle) (Movie clip 70.9).

pedunculated.35,36 Valvular myxomas are defined as a myxoma arising from different parts of the valvular apparatus (valve leaflets, annulus, commissure, junction area, or subvalvular apparatus). A mitral valve myxoma, for example, has variable characteristics by echocardiography: pedunculated,37 sessile,38 nonpedunculated,39 hetero-

geneous,40 homogeneous echogenic,38 multilobulated mobile,41,42 well-circumscribed,42 or an irregular adherent mass. Cardiac myxomas are generally first diagnosed by TTE, and are often an unexpected finding. TEE is usually complementary by confirming and further defining the features.


1471

Fig. 70.10: Live/real time three-dimensional transesophageal echocardiography. Arrow shows a myxoma attached to the middle portion of the atrial septum viewed from the left side. (AV: Aortic valve; LA: Left atrium; RV: Right ventricle) (Movie clips 70.10).

A

C Figs 70.11A to C

B

1472


D

Despite the individual variability of myxomas, TTE typically reveals a homogenous echogenic masses arising within a cardiac chamber or from the valve leaflet with areas of echolucency correlating with hemorrhage or echo bright areas correlating with necrosis and calcification (Fig. 70.13, Movie clip 70.13). On M-mode, the tumor fills the left atrium in systole. During diastole, the tumor prolapses into the mitral valve orifice. Because the tumor partially obstructs the mitral valve orifice, the mitral E-F slope is decreased, suggesting a persistent gradient across the valve and impaired left ventricular filling. The pattern can mimic M-mode pattern of mitral stenosis except the valves are not thickened. Left atrial myxomas on 2D echocardiogram generally appear as mobile, rounded, or ovoid echogenic masses that lie completely within the atrial cavity during systole but may prolapse into or through the mitral valve during diastole (Fig. 70.14). These most commonly arise from the interatrial septum. Their point of attachment is best demonstrated in an apical or subcostal four-chamber view. Large prolapsing myxomas generally interfere with left ventricular inflow and mitral valve diastolic motion.43 The portion of the tumor protruding into the LV in diastole is very mobile, and because of this it has a greater potential to embolize as compared to the remaining of the tumor (Movie clip 70.13). Myxomas typically have multiple internal reflective interfaces that give the tumor a finely speckled appearance and make the body of the tumor as reflective as its margins.44 Bright echoes can be due to localized calcifications. Visualization of echo-free region in a left atrial mass due to areas of hemorrhage or necrosis may be a useful feature in differentiating

Figs 70.11A to D: Two-dimensional (A and B) and live/real time three-dimensional (C and D) transesophageal echocardiography of right ventricular myxoma. (A) The tumor (T) is visualized in the right ventricular (RV) outflow tract beneath the aortic valve (AV). (B) Doppler studies. Color Doppler examination shows turbulent signals (arrow in the upper panel) in RV and pulmonary artery (PA). Continuous wave Doppler interrogation shows high velocity flow signals consistent with obstruction. (C) Arrowheads show large echolucencies consistent with hemorrhages in the tumor (T). Arrow points to a linear area of calcification. (D) The dotted line shows the echogenic area of attachment of the tumor viewed en face. It measured 1.47 × 1.44 cm, area 1.04 cm2. The aortic (AO) wall adjacent to the tumor attachment area is also echogenic. As shown in the movie clips 70.11C (Parts 1–3), the three-dimensional data set was cropped from the bottom to the tumor attachment just beneath the AV. Then, the data set was rotated to fully delineate en face the echogenic area of tumor attachment. In Movie clips 70.11C Part 3, the AO wall was further cropped to reveal the vessel lumen and the mobile tumor tissue (red arrow) at the AO root level. Two other movie clips 70.11D and E also show tumor attachment (arrows) beneath the AO root. (RA: Right atrium; TV: Tricuspid valve) (Movie clips 70.11A, C parts 1 to 3, D and E). Source: Reproduced with permission from Khairnar P, Hsiung MC, Mishra S, et al. The ability of live three-dimensional transesophageal echocardiography to evaluate the attachment site of intracardiac tumors. Echocardiography. 2011;28(9):1041–5.

myxoma from thrombus or vegetation.44 Transducer angulations are a key in recognizing the tumor. Doppler echocardiography can reveal mitral valve regurgitation caused by tumor interfering with normal valve closure. and also demonstrate an increased transvalvular gradient produced by mitral orifice obstruction. Myxomas must be differentiated from vegetations, atrial thrombi, and other tumors or tumor-like structures (Fig. 70.15).31,45 The characteristic appearance, motion, and site of origin of most myxomas distinguish them from the majority of atrial and valvular masses. Myxomas arising from locations other than the atria tend to have unusual shapes and be nonprolapsing, which make them more difficult to diagnose correctly. Valvular vegetations usually can be differentiated from left atrial or valvular myxomas by the clinical setting. The presence of valve disruption is a very strong evidence against a myxoma. A cardiac mass in association with rheumatic mitral stenosis, atrial fibrillation, or dilated cardiomyopathy is much more suggestive for a thrombus than a myxoma. Atrial thrombi tend to be located more in the atrial appendage compared to atrial myxoma, which tend to originate from the septum and occupy the atrial chamber. Thrombi are laminated, immobile, and have broad base attachment. Myxomas are usually smooth, symmetrical, and frequently calcified. Metastatic tumors generally have extension to other structures (e.g. pulmonary veins in lung malignancies).


A

B

C

D

1473

Figs 70.12A to D: Real time two- (A) and three-dimensional (B to D) transthoracic echocardiography in right ventricular myxoma. (A) The arrowhead points to a large myxoma in the right ventricle (RV) visualized in the apical four-chamber view. Tumor attachment is not visualized. (B to D) The arrowhead in B points to the large myxoma. The arrowheads in C show attachments of the myxoma to the RV inferior wall; D shows one of the attachments (arrow) of the tumor to the tricuspid valve using the QLab on the system. (LA: Left atrium; LV: Left ventricle; RA: Right atrium) (Movie clips 70.12 B–D Parts 1 and 2). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609.

RA myxomas can be visualized using subcostal and apical four-chamber views. Prior to the advent of 2DE, RA myxoma were difficult to diagnose with M-mode unless when present behind the tricuspid valve only when protruding to the RV. As with left atrium, RA myxomas on TTE are globular in shape with defined borders. Obstruction of the tricuspid valve can alter the leaflet motion causing tricuspid stenosis or regurgitation. They may be associated with RA and ventricular dilation, and cause paradoxical motion of the interventricular septum. RA myxomas should be differentiated from normal

congenital variants, such as Chiari network or persistent Eustachian valve, which appear as linear serpiginous echoes in the right atrium and lack the globular shape and bulk typical of myxoma.46 RA myxomas should also be differentiated from foreign bodies including right heart catheters, and pacemaker wires that can mimic cardiac masses, particularly when superimposed thrombus is present.47 Malignant tumors can be differentiated from myxomas when extension from the IVC is detected. Right ventricular myxomas originate from the free wall or the interventricular septum. They appear as a

1474


Fig. 70.13: Two-dimensional transesophageal echocardiography. A huge myxoma is seen occupying almost the whole of the left atrium (LA) with a broad attachment to the atrial septum. Highly reflectile component of the tumor represents calcification. The portion of the tumor protruding into the left ventricle (LV) in diastole is very mobile and because of this, it has a greater potential to embolize as compared to the remaining of the tumor. (RA: Right atrium; RV: Right ventricle) (Movie clip 70.13).

Fig. 70.15: Two-dimensional transthoracic echocardiography. Fat in the tricuspid valve annulus. Arrow points to a prominent echodensity in the anterior tricuspid valve annulus indicative of fibrofatty tissue. This should not be mistaken for a mass lesion. (RA: Right atrium; RV: Right ventricle) (Movie clip 70.15).

mass that lie within the body of the RV during diastole and extend toward the right ventricular outflow tract or prolapse through the pulmonic valve during systole.48 The differential diagnosis may include: thrombus, tumors

Fig. 70.14: Parasternal long-axis view showing a left atrial myxoma prolapsing into the left ventricle. (Ao: Aorta; LA: Left atrium; LV: Left ventricle). Source: Dr Stephen Downing, Erie County Medical Center, Buffalo, NY.

of other origin, vegetation, prominent moderator band, and foreign bodies such as Swan–Ganz catheter and transvenous pacemaker. Left ventricular myxomas are extremely rare49 and must be differentiated from other left ventricular tumors, thrombi, false tendons, and prominent or calcified papillary muscles. Left ventricular thrombi are generally distinguished by associated LV wall akinesis or dyskinesis. 3DTTE may provide additional information in assessing myxomas in different locations. It has the capacity to section the mass and view it from different angles, demonstrating maximum dimension using multiplane probes or stacked 2D planes (Movie clips 70.11A to F), giving the examiner a more comprehensive assessment of the mass and possibly additional information about echolucency (Figs 70.16A to C; Movie clips 70.16A and B–D).5,7,9 The attachment of the tumor is much better delineated by the 3D technique (see Fig. 70.6B and C). Contrast echo is another useful technique. With contrast echo, the appearance of hyperenhancement of a suspected myxoma is supportive evidence. After diagnosis, surgery should be performed urgently, in order to prevent complications such as embolic events or obstruction of the mitral orifice. Follow-up examination, including echocardiography, should be performed regularly.50 Recurrence rates reported for cardiac myxomas are 4–7% for sporadic cases and 10–21% for familial cases.


A

C

Although recurrence rates are high, second recurrences are rare.51 Follow-up echocardiography is recommended after surgical tumor resection. Particularly in large size myxoma, where there is a significant recurrence rate of 5%.

Papillary Fibroelastoma Papillary fibroelastomas (PFEs) are the second most common primary cardiac neoplasms, accounting for 5% of all tumors of the heart52 and 7.9% of benign primary cardiac tumors. However, they are the most common valvular tumors.53,54 The true incidence may be underestimated55 because PFEs are often asymptomatic. It is frequently observed between the fourth and the eighth decade of life.56 The pathophysiology of this tumor origin is variable. It can be seen in patients with long-standing heart disease

1475

B

Figs 70.16A to C: Three-dimensional (3D) echocardiographic images cropped to show a left atrial myxoma attached to the interatrial septum (A to C). 3D images demonstrate the finely speckled appearance typical of myxomas. Source: Dr Fredrich Albrecht, Suburban Cardiology, Buffalo, NY (Movie clips 70.16A and B).

suggesting a post-traumatic tumor or as a degenerative process.55,57 Other etiologic hypothesis include relation to organized thrombi,58 or a latent development postradiation exposure.59 Gross pathological specimen resembles a sea anemone. Because of the papillary configuration and soft, fragile nature, PFEs are a potential cause of ostial coronary obstruction, leading to myocardial ischemia or infarction.60,61 The multiple fonds with recesses may also act as a substrate for fibrin and platelet aggregation, with subsequent peripheral or central embolization, depending on their cardiac location.62 The risk of embolization is higher in PFE compared to myxomas (34% compared to 24%)54 because PFE commonly arise in the high flow and high pressure systemic outflow tract of the heart (e.g. aortic valve or LV).63

1476


A

B1

B2

Figs 70.17A and B: (A) Two-dimensional transthoracic echocardiography (parasternal long-axis view) of a patient with a papillary fibroelastoma presenting as an 0.8 × 0.8 cm mobile echogenic mass at the level of the sinotubular junction attached to the aortic surface of one of the aortic valve leaflets. Source: Dr Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY; (B) Two-dimensional transesophageal echocardiography showing a papillary fibroelastoma attached to the aortic valve causing aortic insufficiency (AI) as shown by color Doppler (right panel). (Ao: Aorta; LA: Left atrium; LV: Left ventricle). Source: Dr. Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY (Movie clip 70.17). Transesophageal echo movie clip showing a papillary fibroelastoma attached to the aortic valve. Source: Dr Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY.

Aortic (Figs 70.17 and 70.18; Movie clips 70.17 and 70.18A and B) and mitral leaflets are the most frequent sites of origin, representing 60–90% of the diagnosed cases, followed by tricuspid (Figs 70.19 and 70.20)64 and pulmonary valves [Figs 70.21A to F; Movie clips 70.21B, C(Parts 1and 2) and E, B–E].10,53,56,65 Approximately 77% of these tumors originate on the valves, and the other 23% in the endocardial nonvalvular surface.53 Echocardiography remains the modality of choice to identify and characterize PFEs.66 PFEs normally appear as mobile, small, pedunculated, and echodense formations.67 The rounded, centrally radiolucent tumor is outlined with a refractile linear echo.68 They are well demarcated and homogeneously textured in appearance, having a speckled interior with stippling near the edges, which correlates with the papillary projections on the surface of the tumor (Figs 70.22A and B; Movie clip 70.22; Figs 70.23A and B; Movie clips 70.23A and B).65 Half of PFEs appear

pedicled65 with a short stalk attached to the valve. Fingerlike projection on the fibroelastoma produce a prominent fluttering appearance of the tumor surface, which is a distinguishing feature on real time 2D TTE. These tumors rarely exceed 1 cm in diameter and are usually attached by a small pedicle to one of the cardiac valve leaflet edges. Other less common anatomical sites for PFE origin include: right atrium, RV, left atrium, LV, left ventricular outflow tract (LVOT), atrial or ventricular septum, and coronary ostia.69 Doppler echocardiography usually demonstrates either minimal or mild regurgitation but rarely significant regurgitation or stenosis.70,71 TTE has a sensitivity and specificity of 88.9% and 87.8%, respectively, with an overall accuracy of 88.4% for the detection of PFE ≥ 20 mm. An overall TTE sensitivity of 61.9% is reported in case of tumor dimension ≤ 20 mm.65 A higher sensitivity is reached with TEE, particularly for smaller PFEs.65 3D TTE has also been successfully employed in PFE diagnosis.10,72,73


1477

A

B

C

Figs 70.18A to C: (A) Enlarged two-dimensional (2D) echocardiogram apical four-chamber view; (B) two-dimensional transesophageal echocardiogram (2D TEE), and (C) three-dimensional transesophageal echocardiogram (3D TEE) showing a papillary fibroelastoma attached to the chordal apparatus of the mitral valve. (LA: Left atrium; LV: Left ventricle; RV: Right ventricle). Source: Dr Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY (Movie clip 70.18A). 2D echo movie clip showing a papillary fibroelastoma attached to a chordal apparatus of the mitral valve. Source: Dr. Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY (Movie clips 70.18A and 70.18B). 2D TEE movie clip showing a papillary fibroelastoma attached to a chordal apparatus of the mitral valve. Source: Dr Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY.

Fig. 70.19: Transesophageal echocardiogram of a patient with a papillary fibroelastoma on the atrial surface of the anterior leaflet of the tricuspid valve. The mass presents as a large (1.56 × 1.2 cm), sessile, heterogeneous, mobile density with shimmering at the blood–tissue interface. (RA: Right atrium; RV: Right ventricle). Source: Dr Hashmat Ashraf, Chief of Cardiac Surgery, Buffalo General Medical Center, Buffalo, NY.

Fig. 70.20: Live/real time three-dimensional transthoracic echocardiographic evaluation of tricuspid valve fibroelastoma. The arrow shows a fibroelastoma attached to the septal leaflet (S) of the tricuspid valve. (AO: Aorta; LA: Left atrium; RV: Right ventricle) (Movie clip 70.20). Source: Reproduced with permission from Pothineni KR, Duncan K, Yelamanchili P, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: incremental value over the two-dimensional technique. Echocardiography. 2007;24(5):541–52.

1478


A

B

C

D

E

F

Figs 70.21A to F: Pulmonary valve fibroelastoma. (A) Two-dimensional transthoracic echocardiography. Arrowhead points to fingerlike projections on the fibroelastoma; (B to E) Live/real time three-dimensional transthoracic echocardiography; (B) Arrowhead points to fibroelastoma and the arrow to the echogenic stalk attaching it to the pulmonary valve (PV); (C) Cropping and sectioning the tumor and viewing it en face shows no evidence of echolucency; (D) Arrowhead points to finger-like projections (fronds) on the fibroelastoma; (E) Ex vivo imaging of the resected fibroelastoma shows a dense central core and multiple finger-like projections (arrowheads); (F) Gross pathological specimen of fibroelastoma showing multiple frond-like structures resembling a sea anemone (left) and histopathology of the surgical specimen demonstrating a central core of collagen and elastin covered by a single layer of endothelial cells (right). (AO: Aorta; AV: Aortic valve; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle; RVO: Right ventricle outflow tract) (Movie clips 70.21B, 70.21C Parts 1 and 2, and 70.21E). (Source: Reproduced with permission from Singh A, Miller AP, Nanda NC, Rajdev S, Mehmood F, Duncan K. Papillary fibroelastoma of the pulmonary valve: assessment by live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2006;23(10):880–3.


A

1479

B

Figs 70.22A and B: Aortic valve fibroelastoma. Two-dimensional transesophageal echocardiography. Parasternal long-axis (A) and short-axis (B) views. Arrowhead in A points to a mobile rounded mass attached to the right coronary cusp (arrow in B). The mass has prominent, short, discrete projections on the surface, resembling a sea urchin or fronds of a curtain, and an echogenic central area from collagen deposition. These findings are typical of a fibroelastoma. (AO: Aorta; LA: Left atrium; LAA: Left atrial appendage; RA: Right atrium; RV: Right ventricle) (Movie clip 70.22).

A

B

Figs 70.23A and B: Tricuspid valve fibroelastoma. Two-dimensional transthoracic echocardiography. Right ventricular inflow (A) and parasternal short-axis; (B) views show an echodensity with small, multiple spicule-like structures typical of a fibroelastoma (arrowhead). (AV: Aortic valve; RA: Right atrium; RV: Right ventricle) (Movie clips 70.23A and B).

PFEs are easily distinguished from myxomas, by size and location. Myxomas commonly arise in the left atrium with a pedicle attached to the region of the fossa ovalis.22 Myxomas are seen less frequently in the right atrium or ventricles and rarely involve the mitral valve. PFEs may be differentiated from fibromas, which are nonencapsulated and highly refractile, ovoid, and usually solitary masses that occur primarily in children and commonly involve the LV, interventricular septum, and RV.74,75 PFE may

be difficult to distinguish from valvular myxoma, giant Lambl’s excrescences (Figs 70.24A and B; Movie clip 70.24), and valvular vegetations. PFEs usually attach on the downstream side of the valve, whereas vegetations occur on the upstream side and are usually associated with clinical signs of sepsis or symptoms of endocarditis. Primary surgical excision is the recommended therapy for symptomatic PFEs, with left heart side location and with a specific clinical picture suggestive for possible

1480


A

B

Figs 70.24A and B: Two-dimensional transesophageal echocardiography. Lambl’s excrescence. Arrowhead points to a Lambl’s excrescence on an aortic (AO) valve cusp. (LA: Left atrium; LV: Left ventricle; RV: Right ventricle) (Movie clip 70.24).

embolization.53,65 Asymptomatic patients with large mobile masses (≥ 1 cm) have an increased risk of cardiovascular complications from embolization and sudden cardiac death and should undergo a curative surgical excision.65 Asymptomatic patients with small nonmobile lesions (< 1 cm) should be closely followed up with echocardiography until symptoms develop or tumors enlarge and become mobile.76–78 TEE performed before and during surgery can demonstrate the exact location of the tumor, influence surgical approach, and guide complete tumor excision.61

Cardiac Fibroma Benign cardiac fibromas, when diagnosed, are seen almost exclusively in the pediatric population.79 Adult cases have been reported but are exceedingly rare.80,81 It is the second most common primary ventricular neoplasm after rhabdomyomas. Grossly, these tumors are firm and nonencapsulated, intramural lesions ranging in size from 3 cm to >10 cm in diameter.22 Clinically, cardiac fibromas may present as shortness of breath, dizziness, syncope, and heart failure. Symptoms occur when the tumor increases in size causing obstructive disease. Cardiac fibromas may also be responsible for asymptomatic murmurs since childhood, or be an origin for arrhythmias. Fifty percent are asymptomatic. Cardiac fibromas can be found incidentally as calcification in lower mediastinum on thoracic spine radiograph, or on CT of the chest. They most commonly occur in the RV (Figs 70.25A to C; Movie clips 70.25AB, CB–C)7 and are

usually associated with the interventricular septum. On occasions, they can occur on the lateral wall or in the apex of the RV. Echocardiography helps in confirming the presence of a fibroma that is found primary within the interventricular septum or anterior free wall of the RV.82 Central calcification is frequent. It can obstruct the mitral orifice and produce significant obstruction to inflow. It can also present as massive tumor causing right ventricular outflow obstruction or displace the septum against the free wall of the LV, or shift the tricuspid valve backward toward the atrium. Fibromas are difficult to differentiate from rhabdomyomas, as both can present as a solitary, large mass, particularly if intracavitary. However, their characteristic location within the interventricular septum83 or within the ventricular free wall84 often aids in the appropriate diagnosis. Cardiac magnetic resonance (CMR) is very helpful in showing anatomical details, and differentiating primary cardiac tumors from thrombus.85 The heterogeneity of the tissue component presents as hypointense T1 signal with absent early vascular enhancement on perfusion imaging, and avid delayed enhancement suggesting a benign etiology and fibrous tissue.86 These tumors require surveillance imaging due to the potential for recurrence.

Cardiac Rhabdomyoma Cardiac rhabdomyoma is the most common primary cardiac tumor in pediatric age group.87,88 This tumor is


A

C multicentric and can occur in the ventricular free wall and interventricular septum.88–90 It occurs in equal frequency in the right and left ventricles. Diagnosis can occur in the prenatal period; however, the majority are diagnosed in infancy. The incidence of tuberous sclerosis in patients with cardiac rhabdomyoma has been reported to be between 30 and 50%.91 Clinically, rhabdomyoma can lead to life-threatening ventricular arrhythmia or obstruction of ventricular filling or outflow with intracavitary extension seen in 50% of patients. Echocardiography is an ideal tool to diagnose rhabdomyomas. These tumors tend to appear as multiple homogenous, well-circumscribed, echogenic ventricular masses. They may be intracavitary or intramural masses in RV and LV. They have been described as having a speckled appearance. A pedunculated rhabdomyoma occupying or protruding into the ventricular cavity and aortic valve with significant LVOT obstruction has been reported.92

1481

B

Figs 70.25A to C: Right ventricular fibroma. Two-dimensional (A) and live/real time three-dimensional (B and C) transthoracic echocardiography. (A) Arrowhead points to a single mass in the right ventricle (RV); (B and C) The arrowhead (B) points to a highly echogenic mass occupying right ventricle (RV) cavity and outflow tract. Sectioning the mass and viewing it en face demonstrates two separate tumors (arrowheads in C). (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium) (Movie clips 70.25B–C Parts 1 to 3). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609.

When outflow obstruction is present, pulsed and continuous wave Doppler can determine the degree of outflow gradient and help guide management. The presence of multiple nodular masses in several chambers of the heart helps differentiate rhabdomyoma from other primary cardiac tumors (e.g. myxoma, fibroma, or other benign tumors). 2D echocardiogram is also a useful method of screening asymptomatic infants and children with tuberous sclerosis for the presence of cardiac tumors.91 Surgical intervention may be required for children if a rhabdomyoma causes severe clinical symptoms either due to life-threatening dysrhythmia or outflow obstruction refractory to medical treatment.93 Spontaneous regression has been reported.94

Cardiac Lipomas Lipomas of the heart are most frequently located in the LV (Figs 70.26A to C; Movie clips 70.26AB–CA–C), RV

1482


A

C (Figs 70.27A and B; Movie clips 70.27 (Parts 1 to 3),7 and right atrium (Figs 70.28A to C; Movie clip 70.28).22 Clinically, these tumors are silent, although conduction disturbances have been reported.95 Subepicardial tumors are large, often pedunculated, whereas subendocardial lipomas are typically sessile. About 25% are completely intramyocardial.22 Valvular lipomas are rare, and have been described on the mitral and tricuspid valves.96 Lipomas are differentiated from left ventricular myxomas in that lipomas are less mobile and generally more echodense. These tumors need to be differentiated from lipomatous hypertrophy of the interatrial septum (Figs 70.29A and B), which is characterized by accumulation of adipose tissue in the atrial septum.97 In the subcostal views, globular thickening of the interatrial septum with central sparing gives what has been described as a “dumbbell shape” to the atrial septum with lipomatous hypertrophy.

B

Figs 70.26A to C: Left ventricular lipoma. Live/real time threedimensional transthoracic echocardiography. The arrowheads in A and B point to a highly echogenic mass in the left ventricle (LV). Further cropping of the three-dimensional data set shows the presence of two lipomas (arrowheads in C) in the left ventricle. Arrow in the movie clips 70.26A and B points to the lipoma that is highly echogenic and shows no echolucencies on cropping. Movie clip 70.26C shows another patient with a left ventricular lipoma (arrow) together with the surgically resected specimen. A few trabeculations are also present adjoining the lipoma in the left ventricular apex. (RV: Right ventricle). (Movie clips 70.26A–B, C).

Valvular lipomas are not easy to differentiate from other valvular tumors such as myxomas, PFEs or fibromas, or valvular vegetations. MRI may aid confirming the fatty nature of the tumor.98

Cardiac Hemangiomas Hemangiomas are the most common benign vascular tumors of the heart (Figs 70.30A to D; Movie clip 70.30 B).8 These tumors are usually solitary but may be multiple.99 They may occur anywhere in the heart including the epicardium, often in association with pericardial effusion.99 They may be either intracavitary or intramural. Intramural hemangiomas occur most commonly on the right side of the heart (Figs 70.31A to D; Movie clips 70.31A, B, and D Parts 1–2),34 particularly in the interventricular septum.99 Clinical signs depend on anatomical location. Congestive heart failure occurs with large intracavitary


A

1483

B

Figs 70.27A and B: Right ventricular lipoma. Live/real time three-dimensional transthoracic echocardiography. (A) The arrow points to a large markedly echogenic lipoma interdigitating and infiltrating the right ventricle (RV) free wall. (B) Surgical specimen. (LA: Left atrium; LV: Left ventricle) (Movie clips 70.27 Parts 1 to 3). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609.

A

B

C

Figs 70.28A to C: Two-dimensional echocardiography showing a cardiac lipoma attached to the apicoseptal left ventricular wall (A). CT with (B) and without (C) IV contrast showing a hypodense LV lipoma. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Dr Steven Horn, Medical Director Noninvasive Cardiology Lab, Kalieda Health, Buffalo, NY (Movie clip 70.28).

1484


A

B

Figs 70.29A and B: Two dimensional transesophageal echocardiography. Lipomatous hypertrophy of the atrial septum. (A) Arrow points to thickening of atrial septum that spares foramen ovale. This is caused by fatty infiltration of the septum and usually has no clinical sequelae. (B) Massive lipomatous hypertrophy (arrowheads) affects the entire atrial septum and occupies most of the right atrium (RA) in another patient. (LA: Left atrium; RA: Right atrium; RPA: Right pulmonary artery; SVC: Superior vena cava). (Courtesy of Dr Allan Schwadron, Dothan, AL).

tumors restricting filling of right heart chambers.100 The tumor may simulate infundibular pulmonic stenosis when they involve the upper portion of the interventricular septum.97 Recurrent pericardial effusions are frequent presentation.101,102 2D echocardiographic imaging shows echo-free areas within the mass, representing vascular channels (Figs 70.32A and B; Movie clip 70.32)5 and cavernous lakes. These tumors are generally nonpedunculated, nonhomogenous, solitary masses. When seen in the right heart and associated with a pericardial effusion, they are more suggestive of hemangioma than myxoma, rhabdomyoma, or other primary intracardiac tumors. Spontaneous regression of cavernous hemangiomas has been documented.103

MALIGNANT PRIMARY CARDIAC TUMORS Sarcomas Malignant primary tumors of the heart account for onequarter of all primary cardiac tumors, the vast majority of which are sarcomas (95%; Fig. 70.33; Movie clips 70.33A and B).7 The most common primary malignant cardiac neoplasms in the adult are angiosarcomas (33%) and rhabdomyosarcomas (21%), followed by pericardial

mesotheliomas (16%), fibrosarcomas (11%), primary cardiac lymphomas (PCLs; 6%), osteosarcomas (4%), neurogenic sarcomas (2%), leiomyosarcomas (<1%; Figs 70.34A to C; Movie clip 70.34)9, liposarcomas (<1%), and synovial sarcomas (<1%).104 In addition to identifying the presence of a cardiac tumor, echocardiography provides valuable information regarding the anatomical location (right vs left heart chambers, intracavitary vs intramural), tumor extension (Figs 70.35A to H; Movie clip 70.35; valves, arteries, veins, and pericardium), physiological consequences such as valvular stenosis and regurgitation, ventricular inflow or outflow obstruction, chamber obliteration and ventricular function, and associated findings such as recurrent pericardial effusion. All of these features taken together help to establish a differential diagnosis of the type of tumor in question and assess its hemodynamic effects on cardiac function.105–107 3D TTE has more recently become a helpful adjunct in the detection and characterization of intracardiac masses, secondary to its improved imaging over 2DE.108 In addition to 2D, 3D, and M mode echocardiography, contrast echocardiographic perfusion imaging has become an important supplement to help classify cardiac masses. Compared with the adjacent myocardium, malignant and vascular tumors, such as sarcomas, hyperenhance with the use of contrast imaging, whereas stromal tumors and thrombi hypoenhance.20,109,110


A

B

C

D

1485

Figs 70.30A to D: Hemangioma involving the mitral valve. (A) Two-dimensional transthoracic echocardiography. Parasternal long-axis view. The arrow points to the mass attached to the anterior mitral leaflet (AML), with a few echolucencies within it; (B) Live/real time three-dimensional transthoracic echocardiography. Apical four-chamber view. The arrow points to a mass attached to the mitral valve. The presence of multiple echolucencies (arrowheads, inset A) within the mass is consistent with a hemangioma; (C) Two-dimensional transesophageal echocardiography. Low esophageal modified five-chamber view. The arrow points to the mass on the AML, with a few scattered echolucencies within it; (D) Histopathology. H&E stain 10x. In addition to the sheet-like areas of “epithelioid” endothelial cells with small vascular spaces typical of epithelioid hemangioma (arrows), this lesion also contains larger, more cavernous vascular spaces (arrowheads). (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). (Movie clip 70.30B). Source: Reproduced with permission from Dod HS, Burri MV, Hooda D, et al. Two- and three-dimensional transthoracic and transesophageal echocardiographic findings in epithelioid hemangioma involving the mitral valve. Echocardiography. 2008;25(4):443–5.

Angiosarcoma is the most frequent type of sarcoma in the adult population and the most common primary malignant cardiac tumor. It occurs more frequently in middle-aged males,104 is predominately right-sided,111 and carries a dismal prognosis.107 Typically, the tumor completely replaces the RA wall, fills the entire cardiac chamber, and invades surrounding structures including the tricuspid valve, free wall of the LV, interventricular septum, right coronary artery, and great veins.112,113 On

pathological examination, cardiac angiosarcoma looks like a lobulated mass with a necrotic and hemorrhagic appearance and is composed of malignant cells forming vascular channels.114 On echocardiogram it often appears as a bulky, mobile, heterogeneous broad-based RA mass near the IVC, extending intracavitary and into the pericardium, occasionally invading the caval veins or tricuspid valve.115 Because of its tendency to invade valves, sarcomas of the tricuspid and mitral valves may mimic

1486


A

B

C

D

Figs 70.31A to D: Right ventricular hemangioma. (A) Two-dimensional transesophageal echocardiography. The tumor (T) is located in right ventricle (RV); (B to D) Live/real-time three-dimensional transesophageal echocardiography; (B) The tumor (arrow) is located in RV; (C) Arrow points to multiple small echolucencies involving the whole tumor including the periphery, typical of hemangioma; (D) The three-dimensional data set was cropped from bottom and rotated to view the echogenic area of tumor attachment (dotted lines). It measured 2.76 × 1.40 cm, area 2.01 cm2. (AV: Aortic valve; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; TV: Tricuspid valve) (Movie clips 70.31A, B, D Parts 1 and 2). Source: Reproduced with permission from Khairnar P, Hsiung MC, Mishra S, et al. The ability of live three-dimensional transesophageal echocardiography to evaluate the attachment site of intracardiac tumors. Echocardiography. 2011;28(9):1041–5.

cardiac angiosarcomas. Angiosarcoma that replaces the atrial wall can also lead to RA rupture, as diagnosed by color Doppler echocardiography and contrast echocardiography.116 On CT imaging, angiosarcoma can be identified as a low-attenuation RA mass, which may be irregular or nodular. On MRI, it shows moderate intensity on T1- and T2-weighted images with local nodular areas of increased signal intensity interspersed to give a cauliflowerlike appearance.117 Clinical presentation is usually nonspecific; however, recurrent pericardial effusions are a common manifestation and should raise a high index

of suspicion.118 There may also be a possible etiological correlation between the HIV infection or Kaposi sarcoma and cardiac angiosarcomas.119 Angiosarcoma is usually associated with complications including pulmonary embolism, right heart failure, cardiac tamponade, SVC syndrome, cardiac chamber and coronary artery fistulas, or cardiac perforation. Rhabdomyosarcoma is the second most common primary cardiac sarcoma, but the most common cardiac tumor in children and adolescents. This tumor arises from embryonic cells in the septum, which may explain


1487

A

Figs 70.32A and B: Left atrial hemangioma. Live/real time threedimensional transthoracic echocardiography. (A) Arrowheads (arrow in Movie clip 70.32) point to two of the large number of closely packed echolucencies in the tumor mass with sparse solid tissue; (B) Resected specimen showing multiple vascular areas. (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle) (Movie clip 70.32). Source: Reproduced with permission from Mehmood F, Nanda NC, Vengala S, et al. Live three-dimensional transthoracic echocardiographic assessment of left atrial tumors. Echocardiography. 2005;22(2):137–43.

B

Fig. 70.33: Right ventricular sarcoma. Live/real time threedimensional transthoracic echocardiography. Arrow points to a mass in the right ventricle (RV) showing large echolucencies surrounded by echogenic band-like tissue giving a “doughnut” appearance. Movie clip 70.33B shows, in a different patient, renal cell carcinoma invading the inferior vena cava (IVC) and the proximal right atrium (RA). Cut section demonstrates a solid tumor with no evidence of necrosis. Surgically resected specimen is also shown. (LA: Left atrium; LV: Left ventricle) (Movie clips 70.33A and B). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609.

1488


A

C

its high prevalence in children younger than 1 year. Rhabdomyosarcomas most commonly arise from either the left or right ventricular wall and frequently invade cardiac valves or interfere with valve function secondary to their mass effect.120 On echocardiogram, it appears as an echodense, multilobular pedunculated mass with irregular borders. While it is most commonly seen originating from the ventricles, it has also been described on 2D echo as a lobulated mobile mass inside the left atrium projecting into the left ventricle during diastole and provoking turbulence.121 Additional case reports have also described an echodense mass that originates from the pulmonary valve and obliterates the right ventricular outflow tract with associated high peak transpulmonary gradients.122 On contrast CT, it shows as a hypodense mass, while on MRI it appears isointense to myocardium on T1-weighted images and demonstrates more or less homogeneous

B Figs 70.34A to C: Left atrial leiomyosarcoma. (A) Live/real time three-dimensional transthoracic echocardiography. The arrows point to a “doughnut”-like appearance of the tumor mass located in the left atrium; (B) Intermediate and high-power microscopic appearances of the leiomyosarcoma. The tumor is composed of pleomorphic spindle cells arranged in a fascicular pattern. Abnormal mitotic activity (inset) was easily identified; (C) Lowpower microscopic appearance of necrotic tumor. The periphery of a necrotic area within the tumor showed acellular stroma and dilated/ectatic blood vessels (arrows) consistent with the echocardiographic findings. (AO: Aorta; LA: Left atrium; LV: Left ventricle) (Movie clip 70.34). Source: Reproduced with permission from Suwanjutah T, Singh H, Plaisance BR, Hameed O, Nanda NC. Live/real time three-dimensional transthoracic echocardiographic findings in primary left atrial leiomyosarcoma. Echocardiography. 2008;25(3):337–9.

enhancement after contrast, although there may be areas of low signal intensity due to central necrosis within the tumor.123,124 Systemic metastases typically develop in the lung, bone, and brain. In most patients, survival time is limited to <12 months. Fibrosarcomas are primarily fibroblastic in origin and appear as firm, gray–white nodules with areas of hemorrhage and necrosis. They can occur on the right and left sides of the heart and invade the cardiac chambers and the pericardium. Echocardiographically, they are most often seen as a mobile, heterogeneous left atrial mass. Because most occur on the left side of the heart, associated signs and symptoms are related to pulmonary congestion, mitral stenosis, and pulmonary vein obstruction. Similar to angiosarcomas and rhabdomyosarcomas, survival is poor.105


A

B

C

D

E

F

Figs 70.35A to F

1489

1490


G

H

Figs 70.35A to H: Aortic leiomyosarcoma in a 43-year-old male. (A to F) A mass (arrowheads) in the descending thoracic aorta (DA). Color Doppler examination shows prominent flow signals in the unobstructed portion of the aorta (AO). This makes thrombus unlikely, because associated spontaneous contrast echoes caused by a low-flow state usually are present. Also, no dissection flap is identified. The arrows in A to C and E to H show a large echogenic mass outside the AO, consistent with hematoma; (G and H) A hematoma (arrow, arrowheads) is seen extending on both sides of the descending aorta (DA, AO), even where the tumor mass is not present. At surgery, the mass was found to be a leiomyosarcoma that involved the aortic wall, resulting in perforation that caused the hematoma (Movie clip 70.35). Source: Reproduced with permission from Suwanjutah T, Singh H, Plaisance BR, Hameed O, Nanda NC. Live/real time three-dimensional transthoracic echocardiographic findings in primary left atrial leiomyosarcoma. Echocardiography. 2008;25(3):337–9.

Primary Cardiac Lymphoma Primary cardiac lymphoma (PCL) is defined as a nonHodgkin lymphoma (NHL) exclusively located in the heart or the pericardium.125–127 The accepted definition of PCL also includes a lymphoma presenting as cardiac disease, especially if the bulk of the tumor is intrapericardial.128 Cardiac 99NHL is commonly associated with HIV infection.129–131 The most typical locations for cardiac lymphomas are the right atrium and RV, and less often the left atrium and LV.132,133 PCL is rare, comprising only 0.5% of all lymphomas and 1.3–2% of all heart tumors.127,128 More than 80% of PCLs are diffuse B-cell NHLs, the majority of which are a large cell type and less often T-cell lymphomas. The two most common manifestations are pericardial effusion and heart failure.134 SVC syndrome, stroke, pulmonary hypertension, aortic valvular obstruction,127 and myocardial infarction have also been reported.128 Atrioventricular and bundle branch blocks, low voltages, and negative T-waves have been reported on electrocardiography (ECG).135 Echocardiography is a good noninvasive diagnostic tool to detect pericardial effusion and the presence of a lymphoma mass (Figs 70.36A and B). Cardiac lymphoma

can appear as a frank multilobulated mass mostly located in the right atrium,136 occasionally in the RV, and rarely in the left cavities.137 Other echocardiographic findings seen in clinical cases were limited thickening of the pericardium or the cardiac wall, decrease of the cardiac kinetics with or without pericardial effusion, and cardiac tamponade.138 ECG-gated MRI helps determine tissue characteristics, location, mobility, and its relationship with surrounding tissues.139

Cardiac Plasmacytoma Primary plasmacytoma of the heart is extremely rare. These tumors, when present in the heart, are usually secondary to metastatic disease or direct extension from the mediastinum. The right atrium is the most common site of cardiac plasmacytoma.140 They also can originate in the atrioventricular groove with a short stalk perforating into the right atrium near the tricuspid valve annulus. Heart failure is the most common clinical presentation. Plasma immunoelectrophoresis detection of monoclonal immunoglobulin G paraproteinemia and k light chains increases the probability for this disease entity. Bence– Jones proteinuria may or may not be present. On gross


A

1491

B

Figs 70.36A and B: Two-dimensional transesophageal echocardiography. Hodgkin lymphoma involving the atrial septum. (A) Fourchamber view demonstrating thickening of the atrial septum (arrowhead) produced by the tumor. Note sparing of the fossa ovalis; (B) Arrowhead shows a large circumscribed echolucent area in the atrial septum containing multiple, bright echo densities (“coin lesion”). (LA: Left atrium; MV: Mitral valve; RA: Right atrium; SVC: Superior vena cava; TV: Tricuspid valve). Source: Reproduced with permission from Miller A, Mukhtar O, et al. Two- and three-dimensional TEE differentiation of lymphoma involving the atrial septum from lipomatous hypertrophy. Echocardiography. 2001;18(3):205–9.

examination, these tumors usually present as a large, friable mass. Definitive diagnostic confirmation is made through postresection histological and histochemical examination demonstrating the classic features of a plasmacytoma. A standard 2D echocardiogram reveals the presence of a large mass in the right atrium (Figs 70.37A to C; Movie clips 70.37A to C), often producing a subtotal obstruction of the diastolic inflow through the tricuspid valve.141 Treatment is usually palliative and consists of resection followed by chemotherapy.

Hydatid Cyst Cardiac hydatid cyst is a rare parasitic disease caused by larvae of Echinococcus granulosus, which is still endemic in many sheep-raising countries. Although the LV is mostly involved in this condition, all cardiac chambers and rarely the pericardium can be affected (Figs 70.38A to Z; Movie clips 70.38A and B; Figs 70.39A to F). Patients can be asymptomatic, have nonspecific symptoms such as chest pain, shortness of breath, or palpitations or present as an acute complication of cyst rupture.142 Echocardiogram usually shows a unique finding of multiple cysts inside the cardiac chambers or the pericardium.

Pericardial Mesotheliomas Primary pericardial mesothelioma is a very rare tumor, with a reported prevalence of <0.002%.143 In addition to

asbestos exposure, other suspected risk factors include radiation exposure, infection (including SV40 and TB), dietary factors, and recurrent serosal inflammation.144 Clinical manifestations include constrictive pericarditis, pericardial effusion, cardiac tamponade, and heart failure. Diagnosis can be challenging and often requires a multimodal imaging approach including echocardiography, MRI, CT, and FDG-PET scans. TTE can show a pericardial effusion comprising a partially organized fibrinous structure and a thickened pericardium. 2DE can be misleading; however, as it can suggest the presence of an abnormal amount of pericardial fluid with a surgical plane for resection. As later pathological findings will reveal, the low-density echogenic region surrounding the heart will be tumor rather than fluid.145 FDG-PET/CT scan demonstrates an intrapericardial accumulation of the tracer, seen with local infection or tumor.146 MRI is emerging as the best modality for demonstrating the extent and nature of the constrictive process, and will show a softtissue mass within the pericardial space that is enhanced with gadolinium DTPA.147 Pericardial fluid cytology is often negative for malignant cells and a diagnosis usually requires tissue for histological evaluation.143,144 The prognosis of primary pericardial mesothelioma is extremely poor due to its late presentation, inability for complete tumor eradication by surgery, and poor response to radiotherapy and chemotherapy.

1492


A

B

C

Figs 70.37A to C: Two-dimensional (2D) transesophageal echocardiogram showing a periaortic right atrial mass representative of plasmacytoma (A to C). (A: Aorta; AV: Aortic valve; LAL Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). (Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY (Movie clip 70.37A). 2D echocardiogram showing a periaortic right atrial plasmacytoma. Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY. Movie clip 70.37B.Transesophageal echocardiogram showing a periaortic right atrial plasmacytoma seen anterior to the aortic valve. Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY (Movie clip 70.37C). Transesophageal echocardiogram showing a pariaortic right atrial plasmacytoma seen on the right atrial side of the interatrial septum. Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY.

Secondary Cardiac Tumors While primary cardiac tumors are very rare, secondary or metastatic heart tumors are the most common tumors of the heart. In clinical practice, secondary cardiac tumors are rarely seen. The frequency of cardiac metastases is generally underestimated—varying from series to series, cardiac metastases were found in up to 25% of postmortem patients who had died of malignancies.148–152 Because of absent or nonspecific signs and symptoms of cardiac involvement, most metastases are diagnosed post mortem. Cardiac metastases mostly appear in patients with disseminated tumor disease; solitary metastases to the heart are very rare. Despite their frequency, metastatic heart tumors only rarely gain clinical attention. Signs of cardiac involvement are often overlooked, since the symptoms of disseminated tumor disease prevail. Like

primary tumors of the heart, metastases may imitate valvular heart disease or cause cardiac failure, ventricular or supraventricular heart rhythm disturbances, con duction defects, syncope, embolism, or, quite often, pericardial effusion (Fig. 70.40). Not infrequently, cardiac tumor invasion contributes to the mechanism of death in affected patients.148–150 In principle, every malignant tumor can metastasize to the heart. The most common tumors with cardiac metastatic potential are carcinomas of the breast, the lung (see Fig. 70.40), the esophagus, leukemia, malignant melanoma (Figs 70.41 and 70.42), and lymphoma (Fig. 70.43).153–155 Of tumors that metastasize to the heart, melanoma has the highest rate of cardiac metastasis, although lung and breast carcinomas are more commonly encountered because of the higher prevalence of these cancers.153–155


A

B

C

D

E

F

Figs 70.38A to F

1493

1494


G

H

I

J

K

L

Figs 70.38G to L


M

N

O

P

Q

R

Figs 70.38M to R

1495

1496


S

T

U

V

W

X

Figs 70.38S to X


Y

1497

Z

Figs 70.38A to Z: Live/real time three-dimensional transthoracic echocardiography. Hydatid cyst. Arrow in the apical four-chamber (A) and short-axis (B) views in a young Asian Indian policeman shows a large mass in the left ventricle (LV), which represents a hydatid cyst that had become smaller since the previous study done a few years ago. This collapse of the hydatid cyst could have been spontaneous or may be related to antihelminthic albendazole therapy, which had been given to this patient. (LA: Left atrium; RV: Right ventricle) (Movie clips 70.38A and B). (C to Z) Live three-dimensional transthoracic echocardiographic assessment of hydatid cyst in the left ventricle in another patient— a 37-year-old Asian Indian male. (C) The arrow points to the large hydatid cyst in the left ventricle (LV) seen on the two-dimensional transthoracic echocardiogram. (B to I) Sequential transverse plane (TP) sections taken at various levels (# 1–5) of the three-dimensional data set. The cyst is not visualized at the level of the body of the mitral valve(C, *), but its basal tip (arrow) comes into view when the section is taken further down at the mitral valve leaflet tips (D). In H and I, the large arrowhead points to a tertiary or grand-daughter cyst located within the secondary or daughter cyst. The small arrowhead in H shows a small great–grand-daughter cyst budding from the tertiary cyst. The arrow points to the parent hydatid cyst. (J to M) Longitudinal plane (LP) sections (# 1 and 2) through the hydatid cyst (arrow). (N) Combined TP and LP sections through the hydatid cyst. (O to T) Only FP (O), combined FP and TP (P and Q), combined FP and LP (R), and combined FP, TP, and LP (S and T) sections through the hydatid cyst. (U to Y) Oblique plane (OP) sections through the hydatid cyst. In X, the OP section is rotated to view the cyst en face. A tertiary or grand-daughter cyst is shown attached to the secondary or daughter cyst by a stalk (small double arrowheads). (Z) Schematic of hydatid cyst. (LA: Left atrium; RA: Right atrium; RV: Right ventricle; S: Stalk). (Movie clips 70.38C–Z). (Source: Reproduced with permission from Sinha A, Nanda NC, Panwar R, et al. Live three-dimensional transthoracic echocardiographic assessment of left ventricular hydatid cyst. Echocardiography. 2004;21(8):699–705.

A Figs 70.39A and B

B

1498


C

D

E

F

Figs 70.39A to F: (A) Transthoracic echocardiography shows a large pericardial hydatid cyst (MS) compressing the left ventricular (LV) lateral wall. It measures approximately 8 cm in diameter and appears to contain layered solid tissue. The patient was an 18-year-old Asian Indian male who had emigrated to South Alabama at the age of 5 from India. He presented with a recent syncopal episode and the electrocardiography (ECG) showed deeply inverted T-waves in anterolateral leads consistent with myocardial ischemia. Initially, the twodimensional echocardiogram appeared to show poor LV function but it soon became apparent that this was artifactual and resulted from the ultrasonic beam passing directly from the aortic root into the cyst; (B and C) The arrows point to multiple intramyocardial coronary vessels imaged within the compressed LV free wall. These were visualized using a high-resolution color Doppler system. Note that the Nyquist limit is set at a very low velocity of 0.16 m/s; (D) The arrows demonstrate a high velocity of 1.2 m/s obtained by color Dopplerguided pulsed Doppler interrogation of an intramyocardial coronary vessel (normal velocity < 0.6 m/s). Thus, there was compression of the LV lateral wall by the cyst that served to explain the ECG changes. A coronary arteriogram also showed systolic emptying of the first marginal branch of the circumflex artery. The cyst was surgically resected and the patient is doing well; (E) Left: Three-dimensional reconstruction demonstrates membrane-like solid tissue in the cyst. Right: Three-dimensional reconstruction of intramyocardial coronary vessels (arrows) in the compressed LV wall; (F) Left upper panel: Hydatid cyst wall and surrounding soft tissue. Left lower panel: Close-up of hydatid scolex with double rows of hooklets (100x). Right panel: Laminated membrane. (C: Pericardial cyst; LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 70.39). Source: Reproduced with kind permission from Kluwer Academic Publishers, Advances in Echo Imaging using Contrast Enhancement, 2nd edition, 1997, Ch. 41 “Echocardiographic detection of intramyocardial coronary obstruction produced by pericardial hydatid CPT,” Fig. 2B. Jamil F, Nanda NC, et al. Echocardiographic Detection of Intramyocardial Coronary Obstruction Produced by Pericardial Hydatid Cyst. Echocardiography. 1997;14(5):459–60.


Fig. 70.40: Apical four-chamber view showing a left ventricular intracardiac metastasis of a ureteral sarcomatoid tumor (blue). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY.

A

1499

Fig. 70.41: Apical four-chamber view showing metastatic melanoma with metastasis to the papillary muscle. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

B

Figs 70.42A and B: Two-dimensional transesophageal echocardiography. Metastatic melanoma involving the right ventricle. (A and B) A huge tumor mass (M, T) is noted in the right ventricle (RV) reaching up to the pulmonary valve. (AO: Aorta; LV: Left ventricle; PA: Pulmonary artery). Source: Reproduced with permission from Nanda NC, Domanski MJ, editors. Atlas of Transesophageal Echocardiography. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:519.

2DE plays an essential role in the detection of cardiac metastases and their complications (Figs 70.44 and 70.40). It can generally be used to determine the location, size, shape, attachment, and mobility of the cardiac tumor. It has a good sensitivity to detect intracardiac tumors, but a lower detection rate for pericardial or paracardial

lesions.155,156 In cases of peri- or paracardial lesions, the transesophageal approach is superior to the transthoracic approach (see Figs 70.42A and B).157,158 Tumors can spread to the heart through four alternative pathways: (a) by direct extension, (b) through hematogenous spread, (c) through the lymphatic system,

1500


Fig. 70.43: Transthoracic two-dimensional (2D) echocardiogram (parasternal long-axis view) of a patient with lymphoma and evidence of a very large and uniform echodense mass anterior and spanning the entire heart with possible extension into the pericardial space. (AV: Aortic valve; LA: Left atrium; LV: Left ventricle; L: Lymphoma).

Fig. 70.44: Subcostal view showing pericardial metastasis (P) and circumferential pericardial effusion (PE) in a patient with metastatic lung cancer. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Dr Edward Spangenthal, Roswell Park Cancer Institute, Buffalo, NY.

and (d) by intraluminal venous extension. About twothirds of all cardiac metastases involve the pericardium, one-third the epicardium or the myocardium, and only 5% the endocardium.148 Tumors such as the bronchial, breast, and esophageal carcinoma, which develop near the heart, may expand by direct extension into the heart, but predominantly by the lymphatics. All preferentially affect the pericardium.148–153 In the case of pericardial involvement, echocardiography can show dense pericardial bands reflecting thickening by inflammation or tumor infiltration. Pericardial effusion can be proven quickly, with high sensitivity. When the pericardium is involved, echocardiography is usually used both as a guidance for pericardiocentesis and for the follow-up of effusions. Tumor cells within the pericardial fluid may verify diagnosis of metastatic pericardial involvement (see Figs 70.43 and 70.44). Malignant melanoma (see Figs 70.41 and 70.42), lymphoma (see Fig. 70.43), leukemia, soft tissue, and bone sarcoma usually spread hematogenously. Myocardial metastases can involve any one of the heart chambers (Figs 70.45A to E, Movie clips 70.45B, C and DE; Figs 70.46A to E; Movie clips 70.46A and B).13,159 Intracavitary cardiac metastases are the least common variety. Echocardiography cannot distinguish intracavitary metastatic tumor from primary cardiac tumors.

Some tumors diffuse along the IVC reaching the right atrium and producing an intracavitary lesion, leading occasionally to obstruction. These include carcinoma of the kidney, hepatocellular carcinoma, leiomyoma of the uterus, and carcinoma of the adrenal cortex. This type of lesion can become so obstructive that it fills the chamber completely and blocks tricuspid movement, resulting in a clinical pattern similar to pericardial constriction or myocardial restrictive disease. Invasion of the heart through the SVC into the atrium can occur in the case of carcinoma of the lung and thyroid gland.148 Carcinoid heart disease is also another entity, which can be diagnosed by echocardiography. Metastatic carcinoid tissue in the liver produces biologically active substances, including serotonin, which cause abnormalities of the right-sided cardiac valves and endocardium. Typical changes include thickening, retraction, and increased rigidity of the tricuspid and pulmonic valve leaflets, resulting in valvular regurgitation or, less often, valvular stenosis. Left-sided valvular involvement is rarely seen.160 Cardiac involvement is present in one-half of the patients with carcinoid tumors. Heart failure resulting from severe tricuspid regurgitation is a common cause of mortality in these patients. Although metastatic carcinoid disease is rare, the echocardiographic findings are pathognomonic and may lead to the diagnosis in a patient in whom it was not considered previously.160


A

B

C

D

E

1501

Figs 70.45A to E: (A) Microscopic examination of a biopsy specimen showing malignant tumor cells with marked nuclear pleomorphism, prominent nucleoli, and high mitotic rate. No glandular or squamous differentiation was noted; (B to E) Two-dimensional transthoracic contrast echocardiography; (B) Precontrast study showing two masses (arrow heads) in the left ventricle (LV) attached to the ventricular septum; (C to E) Postcontrast study. Initial frames showed contrast filling LV cavity and outlining the two masses, but there was no significant tumor enhancement (C). Subsequent beats (D and E) demonstrate prominent enhancement of both metastatic tumor masses consistent with high vascularity seen in a poorly differentiated malignant tumor. RV, right ventricle. (Movie clips 70.45B, C and DE). Source: Reproduced with permission from Yelamanchili P, Wanat FE, Knezevic D, Nanda NC, Patel V. Two-dimensional transthoracic contrast echocardiographic assessment of metastatic left ventricular tumors. Echocardiography. 2006;23(3):248–50.

1502


A

B

C

D

E

Figs 70.46A to E: Metastatic chordoma. (A) Real-time twodimensional transthoracic echocardiography. The arrow points to the chordoma in the right ventricle (RV); (B and C) Live/real time three-dimensional transthoracic echocardiography. Arrows point to echolucencies consistent with hemorrhages and cystic areas, and the arrow heads denote echodense areas produced by fibrotic bands. The less intense areas represent the myxoid stroma; B and C represent in-vivo and ex-vivo studies, respectively; (D and E) Pathological specimen showing the lobulated resected tumor (D); The cut surface (E) shows hemorrhagic and cystic areas (arrows) and dense fibrotic bands (arrow heads). (LA: Left atrium; RA: Right atrium; TV: Tricuspid valve) (Movie clips 70.46A and 70.46B). Source: Reproduced with permission from Pothineni KR, Nanda NC, Burri MV, Bell WC, Post JD. Live/real time three-dimensional transthoracic echocardiographic description of chordoma metastatic to the heart. Echocardiography. 2008;25(4):440–2.


Normal Variants and Other Masses There are several normal variant cardiac structures that may mimic a cardiac mass. In conjunction with clinical presentation, evaluation of their size, shape, location, mobility, and site of attachment by echocardiography helps to differentiate them from malignant pathology.

Chiari Network The Chiari network is an embryological remnant that results from incomplete reabsorption of the right valve of the sinus venosus. It appears as a web-like structure with thread-like components and is present in 2% of the population. Its widely mobile and serpiginous appearance within the right atrium can be confused with other highly mobile pathological structures including vegetations, flail tricuspid leaflet, ruptured chordae tendinae, thrombus, or right heart tumor.46 The key differential points by echocardiogram include (a) identification of two, and ideally three, normal appearing tricuspid valve leaflets; (b) presence of a bright, rotatory, highly mobile echocardiographic target that does not move into the right ventricular inflow tract or RV in diastole as would be typical of a tricuspid leaflet vegetation; and (c) in the four-chamber apical or subcostal view, the typical posterolateral orientation and anteroinferior and medial course of this structure across the right atrium. The use of intravenous bolus contrast material to outline the course of the IVC, right atrium, tricuspid valve, and RV can also be of additional benefit in excluding the presence of RA mass and tricuspid leaflet disruption.46

Eustachian Valve The Eustachian valve, an embryological remnant of the valve of the IVC, commonly appears as a thin flap arising from the anterior rim of the IVC orifice. However, it can also persist as a mobile, elongated structure that projects several centimeters into the RA cavity and has been misinterpreted as an intra-atrial thrombus. Eustachian valves move in a more restricted manner than Chiari networks, and should be imaged from the apical four-chamber view, right inflow tract, and subcostal views to distinguish them from vegetation, tumor, or thrombus in the right atrium. On echocardiogram, it appears as a linear, echodense object.

Thebesian Valve The thebesian valve, also known as the valve of the coronary sinus, is a semicircular fold of the lining

1503

membrane of the right atrium. It can be mistaken for a RA mass on echocardiogram, and varies anatomically more than the Eustachian valve. On echocardiogram, it has been described as an echodense, crescentic fold that resembles bars and bands or threads and networks. It can have fenestrations or present as multiple fine strands at the coronary sinus.161 Clinical practice suggests that the valve may present difficulties for cannulation of the coronary sinus. In autopsy cases, thebesian valves are present in over 70% of hearts.162,163 Over 15% of hearts have a valve that covers more than 75% of the ostium and can be devoid of any fenestrations.162

Crista Terminalis The crista terminalis is a well-defined fibromuscular structure formed by the regression of the septum spurium as the sinus venosus is incorporated into the RA wall. Depending on the amount of regression, the crista terminalis can also be very prominent and mimic a RA mass. On TTE, the crista terminalis is seen as an echodense linear ridge in the posterior RA wall, extending laterally from the atrial septum. On 3DE, it can be more clearly defined as a thick and tapering linear structure in the posterior wall of the right atrium.16

Moderator Band The moderator band, or septomarginal trabeculation, is a muscular trabeculation extending from the lower interventricular septum to the anterior RV wall. It is easily identified because of its location in the RV, carrying the right bundle branch from the bundle of His. It is best seen in the apical four-chamber view and subcostal views, and in the apical view, can be seen as it transverses the RV cavity at midventricular level, connecting the free wall to the interventricular septum. In the parasternal long-axis view of the RV, it can be seen as a large muscular band that crosses the apex of the RV obliquely.

Coumadin Ridge The “Q-tip” sign, also known as the “Coumadin ridge”, is a prominent muscular structure formed between the left atrial appendage (LAA) and the atrial insertion of the left upper pulmonary vein. It was often misdiagnosed as a thrombus until it became well described in the literature. It can be differentiated from a thrombus by its lack of mobility and characteristic location. This tissue may

1504


accumulate fat, creating a mass-like appearance, usually with a thin, proximal part and a thicker, more bulbous, distal part seen on echocardiogram.

Thrombus Cardiac thrombi can be located within the atrial (Figs 70.47A and B, Movie clips 70.47, Figs 70.48A to E)7 and ventricular chambers (Figs 70.49 and 70.50),7 and it can extend to the heart from the vena cava (Figs 70.51A to C) or from the heart to the pulmonary arteries (Figs 70.51A to C and 70.52). They may develop as a consequence of multiple underlying cardiac disorders affecting the valves and myocardium. Echocardiography serves as a cornerstone in the evaluation and diagnosis of these patients. It is considered to be the first-line imaging modality in such patients.

Atrial Thrombus Within the atria, thrombi can be found in the atrial appendages, within the body of the atrium, or in a combination of these areas. They are usually the consequence of poor atrial emptying and blood stasis in conditions such as atrial fibrillation, atrial flutter, and mitral stenosis. They may also be associated with indwelling catheters (see Figs 70.51A to C). The most common location for thrombi in the atrium is the LAA, which cannot be regularly seen by TTE. In this

A

setting, TEE is the gold-standard technique, with a great sensitivity and specificity to detect LAA thrombi.164 These thrombi are seen as echo-reflecting masses in the atrial body or in the apex of the LAA, distinct from the underlying endocardium, observed in more than one imaging plane, and not related to pectinate muscles. This should be differentiated from the mass-like effect, which is a normal variant rarely seen in the LAA on TEE (Figs 70.53A to D; Movie clip 70.53). Other signs that are usually associated with thrombosis in the atrium are low LAA emptying velocities, dilated (area > 6 cm2) and multilobulated LAA, and spontaneous echo contrast.

Left Ventricular Thrombus In the ventricles, thrombi are usually located in the apex. They usually occur in the setting of significant left ventricular dysfunction and after acute anterior and/or apical myocardial infarction. It is extremely rare to have a LV thrombus on the top of a normally contracting LV wall; it is usually adjacent to a hypokinetic and akinetic area of the LV wall. These thrombi have to be seen in at least two views (usually apical and short axis). LV thrombus is frequently suspected. Beside ultrasound artifacts, normal structures and normal variants can be mistaken as thrombus, such as normal or aberrant trabeculae or false tendon, muscle tendon such as moderator band, and papillary muscles.

B

Figs 70.47A and B: Live/real time three-dimensional transthoracic echocardiographic assessment of right atrial thrombus. (A) Arrowhead points to a large mobile serpiginous thrombus in the right atrium (RA) prolapsing into the right ventricle (RV); (B) Cropped segments of the thrombus (arrowheads) demonstrate a homogenous appearance with no echolucencies, indicating absence of clot lysis (Movie clip 70.47). Source: Reproduced with permission from Nanda NC, Hsiung MC, Miller AP, Hage FG: Live/Real Time 3D Echocardiography. Oxford, UK: Wiley-Blackwell; 2010.


A

B

C

D

1505

E Figs 70.48A to E: Live/real-time three-dimensional transthoracic echocardiography. (A and B) Apical (A) and parasternal short-axis (B) views show a large mass (arrow) consistent with thrombus in the right atrium (RA) with possible attachment to the RA free wall; (C and D) Right parasternal views showing the attachment of the thrombus to the RA free wall in the vicinity of the inferior vena cava (IVC) and tricuspid valve (TV) directly opposite the superior vena cava (SVC) entrance into the RA. (LA: Left atrium; LV: Left ventricle; RV: Right ventricle); (E) Schematics of (a) clot, (b) myxoma, (c) sarcoma/chordoma, and (d) hemangioma. The horizontal arrowhead in (a) points to central lysis in a clot, in (b) it points to an area of hemorrhage/necrosis in a myxoma, and in (c) to an area of necrosis surrounded by thick, band-like tissue containing collagen, giving a doughnut-like appearance seen with chordoma and sarcoma. The vertical arrowhead in (b) points to dense calcification in the myxoma. (d) Demonstrates a hemangioma that is completely vascular and the echolucencies involve the whole tumor, including periphery (Movie clips 70.48A–D). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609.

1506


A

B

C

D

Figs 70.49A to D: Two-dimensional (A) and live/real-time three-dimensional (B to D) transthoracic echocardiography in right ventricular thrombus. (A) The arrowhead points to one bifid or possibly two clots in the right ventricle (RV). (B and C) Cropping the three-dimensional (3D) data set demonstrates three separate clots in the RV (arrowheads). (D) Another patient with clots in RV showing central lysis in a cropped 3D image. (LA: Left atrium; LV: Left ventricle; RA: Right atrium) (Movie clips 70.49A, B–C parts 1 to 4, D). Source: Reproduced with permission from Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598– 609.

LV thrombus may be protruding within the LV cavity or flat (mural) lying along the LV wall. It may be homogeneously echogenic, or have a heterogeneous texture often with central lucency. Thrombi may be fixed along LV wall or present an independent motion to a variable extent. Motion commonly involves a portion of the thrombus but might involve the entire thrombus. What differentiates LV thrombus from an artifact is that the motion of the thrombus is independent of the underlying myocardium. Color Doppler tissue imaging may further facilitate this differential diagnosis. Although TTE has high sensitivity and specificity in diagnosing LV thrombus, very often the LV apex cannot be

clearly defined and the presence or absence of a thrombus may be very difficult to establish. In such cases, the use of contrast ultrasound agent injected intravenously can clearly identify the presence of a thrombus and decrease both intraobserver and interobserver variability.165

Vegetation Cardiac vegetation presents as an oscillating or nonoscillating intracardiac mass attached to the valves, other endocardial structures, or implanted on intracardiac material. It is considered to be the pathological hallmark of endocarditis. Endocarditis can involve any of the heart


A

B

C

D

1507

Figs 70.50A to D: Live/real-time three-dimensional transthoracic echocardiogram. (A) Four-chamber view showing no thrombus or aneurysm in the left ventricle (LV); (B) Anterior–posterior cropping displays the large aneurysm containing thrombus (arrow); (C and D) Sectioning of the thrombus (C) and viewing it en face (D) shows no evidence of lysis or liquefaction. (RV: Right ventricle) (Movie clip 70.50). Source: Reproduced with permission from Duncan K, Nanda NC, Foster WA, Mehmood F, Patel V, Singh A. Incremental value of live/ real time three-dimensional echocardiography in the assessment of left ventricular thrombi. Echocardiography 2006;23(1):68–72.

valves, with predilection to prosthetic valves. Diseased valves are more prone to be affected during infectious states. Vegetations are typically attached to the lowpressure side of the valve structure, but may be located anywhere on the components of the valvular and the subvalvular apparatus, as well as the mural endocardium of the cardiac chambers or the ascending aorta. When large and mobile, vegetations are prone to embolism and less frequently to valve or prosthetic obstruction. Two-dimensional and transoesophageal echocardiography serves as the cornerstone in noninvasive detection of vegetation. In the setting of endocarditis, the role of echocardiography is not just the identification of

vegetation; it provides clinically important information on the presence and degree of valvular destruction and their hemodynamic consequences, as well as on the existence of perivalvular infection. Overall, the detection rate for vegetations by TTE in patients with a clinical suspicion of endocarditis averages around 50 to 75%.166,167 The diagnostic yield of the technique in the detection of vegetations is influenced by several factors—image quality; echogenicity and vegetation size; vegetation location; presence of previous valvular disease or valvular prosthesis; experience and skill of the examiner; and pre-test probability of endocarditis.

1508


A

C

TEE enhances the sensitivity to 85–90% for the diagnosis of vegetations, while more than 90% specificity has been reported for both TTE and TEE.167–169 Both TTE and TEE do not permit differentiation between septic and other aseptic vegetations present in conditions such as Libman– Sacks endocarditis in systemic lupus erythematosus, antiphospholipid syndrome, and marantic endocarditis. Vegetations on prosthetic valves are more difficult to detect by TTE than those involving native valves. Therefore, TEE should always be used if the diagnosis of prosthetic endocarditis is suspected. The sewing ring and support structures of mechanical and bioprosthetic valves are strongly echogenic and may prevent vegetation detection within the valve apparatus or its shadow. Thrombus, pannus, and strands can be mistaken as vegetative material given their similar appearance (Figs 70.54A to C; Movie clips 70.54A to C). In large

B

Figs 70.51A to C: Two-dimensional transesophageal echocardiography. Thrombus in the pulmonary artery and the superior vena cava. (A to C) Large thrombi (M,C) are noted in the superior vena cava (SVC) and the right pulmonary artery (RPA) in this patient with an infusion catheter, which acted as the nidus for thrombus. (AO: Aorta; ASC AO: Ascending aorta; LA: Left atrium). Source: Reproduced with permission from Nanda NC, Domanski MJ, editors. Atlas of Transesophageal Echocardiography. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2007:521.

series of prosthetic endocarditis, TEE has shown an 86 to 94% sensitivity and 88–100% specificity for vegetation diagnosis, while TTE sensitivity was only 36–69%.169 In the setting of tricuspid vegetations, TTE allows an easy and correct diagnosis, probably because the majority of patients with tricuspid endocarditis are young intravenous drug abusers with large vegetations. The vegetations are located on the atrial side of the tricuspid valve, in the way of the regurgitant jet. TEE did not increase the accuracy of TTE in the detection of vegetations in tricuspid endocarditis in one study.168,170 Infection or endocarditis on a pacemaker lead is difficult to diagnose by TTE, since pacemaker leads produce reverberations and artifacts that may mask or make difficult the recognition of vegetations close to these structures. In addition, when vegetations were visualized, it was difficult to determine whether tricuspid valve


A

C

E

1509

B

D Figs 70.52A to E: Two-dimensional transesophageal echocardiography. A 78-year-old black female. (A and B) Thrombic obstruction of distal left and right pulmonary arteries. Arrowhead points to a large thrombus in the distal left pulmonary artery (LPA, A) and in the distal right pulmonary artery (RPA, B); (C to E) Thrombotic occlusion of LPA descending lobar branches; (C) Large arrowhead points to the thrombus (TH) and small arrowhead points to an echolucent area of clot lysis. Arrow shows extension of the TH into a descending lobar branch of the LPA; (D) Turbulent flow signals with prominent flow acceleration are noted in a descending lobar branch (labeled 2). Arrow points to the left pulmonary vein (LPV), and arrowhead shows the TH; (E) Color Doppler-guided continuous wave Doppler interrogation (arrow) shows a high systolic velocity of 2.2 m/s and a high diastolic velocity of 1.0 m/s indicative of significant obstruction. (AO: Aorta; T: Transverse plane) (Movie clips 70.52A to E). Source: Reproduced with permission from Kang SW, Nekkanti R, Nanda NC, et al. Transesophageal echocardiographic identification of thrombus producing obstruction of left pulmonary artery descending lobar branches and bronchial artery dilatation. Echocardiography. 2002;19:83–8.

1510


A

B

C

D

Figs 70.53A to D: Transesophageal echocardiographic finding of LAA lobe mimicking a mass lesion. (A) The arrowhead points to what appears to be a mass in or adjacent to LAA; (B) Schematic; (C) Keeping the mass-like lesion in the middle of the monitor screen and rotating the transducer from 0° to 180° shows that the mass-like effect is produced by a lobe (#3) of the LAA; (D) Schematic. Numbers 1 and 2 denote the other two lobes of the LAA. (AO: Aorta; LA: Left atrium; LAA: Left atrial appendage; LV: Left ventricle; M: Mass; MV: Mitral valve; PA: Pulmonary artery; PE: Fluid in the transverse sinus of pericardium) (Movie clip 70.53). Source: Reproduced with permission from Giove GC, Singla I, Mishra J, Nanda NC. Transesophageal echocardiographic finding of left atrial appendage lobe mimicking a mass lesion. Echocardiography. 2011;28:684–5.

endocarditis, lead infection, or both were present. TEE was clearly superior to TTE in this clinical setting (sensitivity 23% vs 94%).171 Regurgitation of the infected valve is present in most cases resulting from a variety of mechanisms. They include prevention of proper leaflet or cusp coaptation by the vegetation and valvular destruction that can result in a small perforation in a cusp, or lead to a complete flail leaflet. Valvular perforation is a frequent complication that may cause severe insufficiency with an acute onset and precipitate heart failure. This is more common in aortic

valves than mitral valves. This carries a poor prognosis in most cases. TTE appears more useful in detecting mitral than aortic perforations. Color flow Doppler imaging allows location of abnormal flows at the areas of anatomical interruption and, therefore, it helps to differentiate mitral cusp perforation from true mitral regurgitation. TEE is recommended if a valve perforation is suspected and TTE is negative or equivocal. In the case of mechanical mitral prosthesis, TEE with color flow mapping is of importance in the diagnosis of paravalvar regurgitation. The presence of a new or


A

C increasing paravalvar regurgitation or valve dehiscence is a major criterion for the diagnosis of endocarditis. Extension of the infection to the perivalvar tissues is a sign of poor prognosis in the evolution of the disease. Extravalvar extension may lead to endothelial erosion, perivalvar abscess, mycotic aneurysm, and intracardiac fistulae.

Perivalvular Abscess Perivalvar cavities are formed when annular infections break through and spread into contiguous tissue. In native aortic valve endocarditis, they generally occur through the weakest portion of the annulus, which is near the membranous septum. Perivalvar abscesses are particularly common in prosthetic valve endocarditis, since the annulus is the usual primary site of infection. A perivalvar

1511

B

Figs 70.54A to C: Two-dimensional (A and B) and three-dimensional (C) transthoracic echocardiography. Tumor mimic following mitral valve replacement. Arrowhead points to subvalvular apparatus (chordae and papillary muscle) remaining in the left ventricle following resection of the native mitral valve and replacement with a prosthetic valve. This could be misdiagnosed as tumor or vegetations. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clips 70.54A to C).

abscess is considered to be present when a definite region of reduced echodensity is found on the echocardiogram, or when echolucent cavities within the valvular annulus or adjacent myocardial structures are found in the setting of valvular infection. Sensitivity and specificity of TTE for abscess detection were 28% and 99%, respectively, compared with 87% and 95%, respectively, with TEE. TEE is especially useful in prosthetic endocarditis. The diagnosis of aortic abscesses were easier than mitral abscesses, both with TTE (42% vs 9%) and TEE (86% vs 57%).8

MICE Mesothelial/macrophage incidental cardiac excrescences, or MICE, are made up of mesothelial cells, macrophages, scattered inflammatory cells and fibrin, and lack a vascular network or supporting stroma.172 Lack of vascularity is an

1512


A

B

Figs 70.55A and B: Real time two-dimensional transthoracic echocardiography. Arrowhead points to a large echogenic mass involving the posterior mitral annulus, consistent with calcification. An echolucent area consistent with liquefaction is seen in B. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clips 55A and B). (Source: Reproduced with permission from Assudani J, Singh B, Samar A, et al. Echocardiography. 2010;27:1147–50).

important feature distinguishing them from localized mesothelial hyperplasia, which can also form incidentally detected excrescences and contain sheets of mesothelial cells, macrophages, and fibrin. They are more commonly found in the left heart chambers and on valve surfaces especially during aortic and mitral valve surgery or in endomyocardial biopsy specimens. On echocardiography, it can appear as a free-floating mass or loosely adherent. It has been described as isointense on MRI compared to myocardium on T1-weighted images and hyperintense on T2-weighted images, without enhancement with contrast.173 While they are benign, they may be potentially mistaken for a primary or metastatic malignancy.

Mitral Annular Calcification Mitral annular calcification (MAC) is a common echocardiographic finding seen mainly in older patients and those with chronic renal failure. Caseous calcification is a rare variant seen as a large, round, echodense mass with smooth borders situated in the periannular region, with no acoustic shadowing artifacts and containing central areas of echolucencies resembling liquefaction.174 The diagnosis is made by TTE in most cases but 2D or 3D transesophageal echocardiogram (Figs 70.55 to 70.59; Movie clips 70.55A and B to 70.58A Parts 1 and 2, B, CD Parts1 and 2-D) are helpful in some cases where the diagnosis is in question to make more

Fig. 70.56: Live/real time three-dimensional transthoracic echocardiography. Cropped three-dimensional data set. The lower arrowhead points to a highly echogenic calcification while the upper arrowhead shows a less echogenic area of uniform appearance. (MV: Mitral valve; TV: Tricuspid valve) (Movie clip 70.56). Source: Reproduced with permission from Assudani J, Singh B, Samar A, et al. Echocardiography. 2010;27:1147–50.

definitive diagnosis and prevent more invasive testing and even exploratory cardiotomy.

Cardiac Calcified Amorphous Tumor Cardiac calcified amorphous tumor (CAT) is another rare benign cardiac mass that can mimic malignancy and


1513

Fig. 70.57: Real time two-dimensional transesophageal echocardiography. The arrowhead denotes posterior mitral annular calcification. Note shadowing and reverberations beneath the calcification. (LA: Left atrium; LV: Left ventricle) (Movie clip 70.57). Source: Reproduced with permission from Assudani J, Singh B, Samar A, et al. Echocardiography. 2010;27:1147–50.

A

B

C

D

Figs 70.58A to D: Live/real time three-dimensional transesophageal echocardiography in caseous mitral annular calcification. (A and B) Four-chamber views. The arrowheads in A and B point to a large echogenic mass involving the posterior mitral annulus, consistent with calcification. In B, the mass shows multiple, discrete, band-like, and punctuate echodensities surrounded by a highly echogenic border. (C and D) Cropping of the four-chamber data set shows both a highly echogenic (lower arrowhead) and a relatively less echogenic (upper arrowhead) components of the mass. Transverse cropping (D) also reveals a pattern of highly echogenic component as well as a relatively less echogenic area with multiple, small, discrete band-like, and punctate echodensities. (AML: Anterior mitral leaflet; AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle). [Movie clips 70.58A (Parts 1 and 2), B to D (Parts 1 and 2)]. Source: Reproduced with permission from Assudani J, Singh B, Samar A, et al. Echocardiography. 2010;27:1147–50.

1514


A

B

Figs 70.59A and B: Two-dimensional transesophageal echocardiography. Extracardiac tumor. (A and B) Tumor (T, arrow) is seen posterior to the aortic root bulging into the left atrium (LA). (AO: Aorta; LV: Left atrium; RV: Right ventricle). Source: Reproduced with permission from Nanda NC, Domanski MJ, editors. Atlas of Transesophageal Echocardiography. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:524.

cause symptoms due to obstruction or embolization of calcific fragments.175,176 Typical findings for CAT include calcium nodules within amorphous fibrinous materials often displaying characteristic histological findings that include nodular calcium deposits, chronic inflammatory cell infiltration, hyalinization, and degenerating blood elements.175 Intracardiac echocardiogram will demonstrate curvy linear densities representative of endomyocardial calcifications.177

Extracardiac Masses In addition to normal cardiac variants, certain extracardiac masses can also mimic cardiac tumors by compressing the cardiac chambers from the outside of the heart and creating a mass effect. Examples include tumors or diseases of the mediastinum (Figs 70.59 to 70.63), hematomas (Fig. 70.64), coronary aneurysms, and pseudoaneurysms. Although not uncommon, pericardial fat deposition when prominent can masquerade as extracardiac tumor (Figs 70.65A and B; Movie clips 70.65A and B). Sclerosing mediastinitis is a rare disorder characterized by the invasive proliferation of fibrous tissue within the mediastinum and frequently results in the compression of vital mediastinal structures including the heart. It can cause compression of the atrial or ventricular cavities and can cause obstruction of the SVC and the pulmonary arteries (Figs 70.60 to 70.63).

Hiatal hernias can also be seen on TTE and TEE as an extracardiac mass compressing the left atrium with associated mild left ventricular hypertrophy with normal function and no thrombus in the LA. If a hiatal hernia is suspected, use of oral contrast or soda during TTE may be diagnostic, but during TEE it carries the risk of aspiration.178 Juxtacardiac pulmonary atelectasis or lobar collapse can also simulate pericardial tumor implants on echocardiographic examination (“pericardial pseudotumor”) from surrounding compressive effusive fluid.179 Echocardiographic delineation of pericardial and pleural anatomy can be used to delineate the atelectatic nature of these masses, combined with ancillary radiographic and CT studies. In addition, drainage of pleural fluid will lead to the disappearance of the masses on echocardiographic examination.

Intracardiac Hardware In addition to intrathoracic masses mimicking cardiac tumors, intracardiac hardware such as Impella percutaneous left ventricular assist device catheters, pacing leads, Swan–Ganz catheters, and central line catheters are also commonly seen left atrial foreign bodies on echocardiography. Catheters and pacemaker leads are usually seen on echocardiography as two parallel thin linear echodensities separated by an echolucent slit that produce typical reverberations and side lobe artifacts


A

C

A Figs 70.61A and B

1515

B

Figs 70.60A to C: Two-dimensional transesophageal echocardiography. Sclerosing mediastinitis. This 43-year-old man presented with respiratory failure. (A) A mass (M) surrounds the left atrium (LA), right pulmonary artery (RPA), and superior vena cava (SVC); (B and C) The mass appears to infiltrate and invaginate into the LA and extends up to the base of the left atrial appendage (LAA). This resembles an intracardiac tumor. (AO: Aorta; AV: Aortic valve; PA: Pulmonary artery; RA: Right atrium; RVO: Right ventricular outflow). Source: Reproduced with permission from Kovach TA, Nanda NC, Kim KS, et al. Transesophageal echocardiographic findings in sclerosing mediastinitis. Echocardiography. 1996;13:103–8.

B

1516


C

Figs 70.61A to C: Two-dimensional transesophageal echocardiography. Sclerosing mediastinitis. Same patient as in Figures 70.60 A and B. Both the right lower pulmonary vein (RLPV) and right upper pulmonary vein (RUPV) demonstrate obstruction near their entrance in the left atrium (LA). The exact sites of obstruction in the lower and upper pulmonary veins, shown by the arrow and the arrowhead, respectively, mark the transition from laminar (red) to disturbed (mosaic) flow; (C) Pulsed Doppler interrogation of the mosaic flow reveals a high velocity of 2.58 m/s, indicative of obstruction. (LV: Left ventricle; M: Mass; RVO: Right ventricular outflow; SVC: Superior vena cava). Source: Reproduced with permission from Kovach TA, Nanda NC, Kim KS, et al. Transesophageal echocardiographic findings in sclerosing mediastinitis. Echocardiography. 1996;13:103–8.

A

B

C

Figs 70.62A to C: Two-dimensional transesophageal echocardiography. Sclerosing mediastinitis. Same patient as in Figures 70.60 and 70.61. (A and B). The arrow points to the site of obstruction in the superior vena cava (SVC) near its junction with the right atrium (RA). Color Doppler examination shows a thin mosaic flow jet in (B), indicative of obstruction; (C) Pulsed Doppler interrogation reveals a high velocity of at least 1.61 m/s. (LA: Left atrium; M: Mass; RPA: Right pulmonary artery). Source: Reproduced with permission from Kovach TA, Nanda NC, Kim KS, et al. Transesophageal echocardiographic findings in sclerosing mediastinitis. Echocardiography. 1996;13:103–8.


A

1517

B

Figs 70.63A and B: Sclerosing mediastinitis. Histology of mediastinal biopsy tissue from the same patient shown in Figures 70.60 to 70.62. (A) Photomicrograph of sclerosing process impinging on mediastinal adipose tissue (congo red, original magnification ×125); (B) Photomicrograph of collagenization of blood vessel wall with narrowing of the lumen (center), a region of cellular fibrosis (above), and a region of acellular fibrosis (below; hematoxylin and eosin, original magnification ×125). Source: Reproduced with permission from Kovach TA, Nanda NC, Kim KS, et al. Transesophageal echocardiographic findings in sclerosing mediastinitis. Echocardiography. 1996;13:103–108.

Fig. 70.64: Two-dimensional transesophageal echocardiography. Hematoma following cardiac surgery. Arrowheads show hematoma that developed around the aortic root following aortic valve replacement. It had a benign course. (AO: Aorta; LA: Left atrium; LAA: Left atrial appendage). Source: Reproduced with permission from Nanda NC and Domanski MJ, editors. Atlas of Transesophageal Echocardiography. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:535.

shadowing other structures. Clinical correlation is important in assessing the echocardiographic presence of such objects. In summary, the integration of the echocardiographic findings with the patient’s medical history and clinical scenario is critical to establishing a differential diagnosis and to determining the hemodynamic consequences

of a cardiac mass or tumor. Serial studies can provide useful information regarding progression, regression, and results of treatment of the mass or tumor. In some cases, additional imaging modalities such as cardiac CT and MRI can provide complementary information that enhances the echocardiographic findings.

1518


A

B

Figs 70.65A and B: Two-dimensional transthoracic echocardiography. Epicardial fat pad. Arrows point to prominent epicardial fat deposition both anteriorly and posteriorly visualized in parasternal long-axis view and around the cardiac apex in the apical four-chamber view (Movie clips 70.65A and B). (LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

REFERENCES 1. Plana JC. Three-dimensional echocardiography in the assessment of cardiac tumors: the added value of the extra dimension. Methodist Debakey Cardiovasc J. 2010;6(3): 12–19. 2. Asch FM, Bieganski SP, Panza JA, Weissman NJ. Real time 3-dimensional echocardiography evaluation of intracardiac masses. Echocardiography. 2006;23(3):218–24. 3. Meng Q, Lai H, Lima J, et al. Echocardiographic and pathologic characteristics of primary cardiac tumors: a study of 149 cases. Int J Cardiol. 2002;84(1):69–75. 4. Lokhandwala J, Liu Z, Jundi M, et al. Threedimensional echocardiography of intracardiac masses. Echocardiography. 2004;21(2):159–63. 5. Mehmood F, Nanda NC, Vengala S, et al. Live threedimensional transthoracic echocardiographic assessment of left atrial tumors. Echocardiography. 2005;22(2):137–43. 6. Müller S, Feuchtner G, Bonatti J, et al. Value of transesophageal 3D echocardiography as an adjunct to conventional 2D imaging in preoperative evaluation of cardiac masses. Echocardiography. 2008;25(6):624–31. 7. Reddy VK, Faulkner M, Bandarupalli N, et al. Incremental value of live/real time three-dimensional transthoracic echocardiography in the assessment of right ventricular masses. Echocardiography. 2009;26(5):598–609. 8. Dod HS, Burri MV, Hooda D, et al. Two- and threedimensional transthoracic and transesophageal echocardiographic findings in epithelioid hemangioma involving the mitral valve. Echocardiography. 2008;25(4):443–5. 9. Suwanjutah T, Singh H, Plaisance BR, et al. Live/real time three-dimensional transthoracic echocardiographic findings in primary left atrial leiomyosarcoma. Echocardiography. 2008;25(3):337–9.

10. Singh A, Miller AP, Nanda NC, et al. Papillary fibroelastoma of the pulmonary valve: assessment by live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2006;23(10):880–3. 11. Pothineni KR, Nanda NC, Patel V, et al. Live/real time threedimensional transthoracic echocardiographic detection of vegetation on a pacemaker/defibrillator lead. Am J Geriatr Cardiol. 2006;15(1):62–3. 12. Hung J, Lang R, Flachskampf F, et al. ASE. 3D echocardiography: a review of the current status and future directions. J Am Soc Echocardiogr. 2007;20(3):213–33. 13. Pothineni KR, Nanda NC, Burri MV, et al. Live/real time three-dimensional transthoracic echocardiographic description of chordoma metastatic to the heart. Echocardiography. 2008;25(4):440–2. 14. Monaghan MJ. Role of real time 3D echocardiography in evaluating the left ventricle. Heart. 2006;92(1):131–6. 15. Zamorano J, Cordeiro P, Sugeng L, et al. Real time threedimensional echocardiography for rheumatic mitral valve stenosis evaluation: an accurate and novel approach. J Am Coll Cardiol. 2004;43(11):2091–6. 16. McKay T, Thomas L. Prominent crista terminalis and Eustachian ridge in the right atrium: Two dimensional (2D) and three dimensional (3D) imaging. Eur J Echocardiogr. 2007;8(4):288–91. 17. Pothineni KR, Nanda NC, Burri MV, et al. Live/real time three-dimensional transthoracic echocardiographic visualization of Chiari network. Echocardiography. 2007; 24(9):995–7. 18. Ekmektzoglou KA, Samelis GF, Xanthos T. Heart and tumors: location, metastasis, clinical manifestations, diagnostic approaches and therapeutic considerations. J Cardiovasc Med (Hagerstown). 2008;9(8):769–77.


19. van Beek EJ, Stolpen AH, Khanna G, et al. CT and MRI of pericardial and cardiac neoplastic disease. Cancer Imaging. 2007;7:19–26. 20. Kirkpatrick JN, Wong T, Bednarz JE, et al. Differential diagnosis of cardiac masses using contrast echocardiographic perfusion imaging. J Am Coll Cardiol. 2004;43(8):1412–19. 21. Mulvagh SL, Rakowski H, Vannan MA, et al. American Society of Echocardiography. American Society of Echocardiography Consensus Statement on the Clinical Applications of Ultrasonic Contrast Agents in Echocardiography. J Am Soc Echocardiogr. 2008;21(11): 1179–201; quiz 1281. 22. Heath D. Pathology of cardiac tumors. Am J Cardiol. 1968;21(3):315–27. 23. Devig PM, Clark TA, Aaron BL. Cardiac myxoma arising from the inferior vena cava. Chest. 1980;78(5):784–6. 24. Alfonso Penta De Peppo, Luigi Sommariva, et al. Cardiac myxoma arising from the inferior vena cava. Tex Heart Inst J. 1992;19(4):288–90. 25. Ferrans VJ, Roberts WC. Structural features of cardiac myxomas. Histology, histochemistry, and electron microscopy. Hum Pathol. 1973;4(1):111–46. 26. Harvey WP. Clinical aspects of cardiac tumors. Am J Cardiol. 1968;21(3):328–43. 27. Greenwood WF. Profile of atrial myxoma. Am J Cardiol. 1968;21(3):367–75. 28. Yuan SM. Mitral valve myxoma: clinical features, current diagnostic approaches, and surgical management. Cardiol J. 2012;19(1):105–9. 29. McCarthy PM, Piehler JM, Schaff HV, et al. The significance of multiple, recurrent, and “complex” cardiac myxomas. J Thorac Cardiovasc Surg. 1986;91(3):389–96. 30. Peters MN, Hall RJ, Cooley DA, et al. The clinical syndrome of atrial myxoma. JAMA. 1974; 230(5):695–701. 31. DePace NL, Soulen RL, Kotler MN, et al. Two dimensional echocardiographic detection of intraatrial masses. Am J Cardiol. 1981;48(5):954–60. 32. Srivastava R, Hsiung MC, Fadel A, et al. Transesophageal echocardiographic demonstration of biatrial myxoma. Echocardiography. 2004;21(2):187–8. 33. Jaleski TC. Myxoma of the Heart Valves: Report of a Case. Am J Pathol. 1934;10(3):399–406. 34. Khairnar P, Hsiung MC, Mishra S, et al. The ability of live three-dimensional transesophageal echocardiography to evaluate the attachment site of intracardiac tumors. Echocardiography. 2011;28(9):1041–5. 35. Meller J, Teichholz LE, Pichard AD, et al. Left ventricular myxoma: echocardiographic diagnosis and review of the literature. Am J Med. 1977;63(5):816–23. 36. Snyder SN, Smith DC, Lau FY, et al. Diagnostic features of right ventricular myxoma. Am Heart J. 1976;91(2):240–8. 37. Vasquez JC, Rosales E, Dueñas R, et al. A large pediculated myxoma of the left ventricle causing outflow obstruction in a young man. J Am Soc Echocardiogr. 2007;20(12):1413. e1–1413.e3.

1519

38. Oliveira R, Branco L, Galrinho A, et al. Cardiac myxoma: a 13-year experience in echocardiographic diagnosis. Rev Port Cardiol. 2010;29(7-8):1087–100. 39. Sanya EO, Kolo PM, Adamu UG, et al. Intracardiac tumor: a risk factor for stroke in the young–a case report. Niger J Clin Pract. 2008;11(1):81–4. 40. Guler N, Ozkara C, Kaya Y, et al. Ruptured abdominal aortic aneurysm after resection of an infected cardiac myxoma. Tex Heart Inst J. 2007;34(2):233–5. 41. Joukhadar R, De Las Casas LE, Lalude O, et al. Cardiac myxoma showing extramedullary hematopoiesis in a patient with beta thalassemia. South Med J. 2009;102(7):769–71. 42. Seder CW, Sakwa MP, Shannon FL. Left ventricular myxoma resection with minimally invasive mitral valve reconstruction. J Heart Valve Dis. 2010;19(4):533–5. 43. Charuzi Y, Bolger A, Beeder C, et al. A new echocardiographic classification of left atrial myxoma. Am J Cardiol. 1985;55(5):614–15. 44. Rahilly GT Jr, Nanda NC. Two-dimensional echographic identification of tumor hemorrhages in atrial myxomas. Am Heart J. 1981;101(2):237–9. 45. Come PC, Riley MF, Markis JE, et al. Limitations of echocardiographic techniques in evaluation of left atrial masses. Am J Cardiol. 1981;48(5):947–53. 46. Werner JA, Cheitlin MD, Gross BW, et al. Echocardiographic appearance of the Chiari network: differentiation from right-heart pathology. Circulation. 1981;63(5):1104–9. 47. Kendrick MH, Harrington JJ, Sharma GV, et al. Ventricular pacemaker wire simulating a right atrial mass. Chest. 1977;72(5):649–50. 48. Ports TA, Schiller NB, Strunk BL. Echocardiography of right ventricular tumors. Circulation. 1977;56(3):439–47. 49. Björk VO, Björk L. Left ventricular myxoma. Thorax. 1965;20(6):534–6. 50. Kuroczynski W, Peivandi AA, Ewald P, et al. Cardiac myxomas: short- and long-term follow-up. Cardiol J. 2009; 16(5):447–54. 51. Turhan S, Tulunay C, Altin T, et al. Second recurrence of familial cardiac myxomas in atypical locations. Can J Cardiol. 2008;24(9):715–16. 52. Piazza N, Chughtai T, Toledano K, et al. Primary cardiac tumours: eighteen years of surgical experience on 21 patients. Can J Cardiol. 2004;20(14):1443–8. 53. Gowda RM, Khan IA, Nair CK, et al. Cardiac papillary fibroelastoma: a comprehensive analysis of 725 cases. Am Heart J. 2003;146(3):404–10. 54. Elbardissi AW, Dearani JA, Daly RC, et al. Survival after resection of primary cardiac tumors: a 48-year experience. Circulation. 2008;118(14 Suppl):S7–15. 55. Edwards FH, Hale D, Cohen A, et al. Primary cardiac valve tumors. Ann Thorac Surg. 1991;52(5):1127–31. 56. Klarich KW, Enriquez-Sarano M, Gura GM, et al. Papillary fibroelastoma: echocardiographic characteristics for diagnosis and pathologic correlation. J Am Coll Cardiol. 1997;30(3):784–90.

1520


57. Taniyasu N, Akiyama K, Iba Y, et al. Papillary fibroelastoma in association with thrombosis on a mechanical valve. Jpn Circ J. 2000;64(10):797–9. 58. Salyer WR, Page DL, Hutchins GM. The development of cardiac myxomas and papillary endocardial lesions from mural thrombus. Am Heart J. 1975;89(1):4–17. 59. Kurup AN, Tazelaar HD, Edwards WD, et al. Iatrogenic cardiac papillary fibroelastoma: a study of 12 cases (1990 to 2000). Hum Pathol. 2002;33(12):1165–9. 60. Jobic Y, Etienne Y, Quintin-Roué I, et al. Left ventricular papillary fibroelastoma: two-dimensional echocardiographic detection and surgical resection. J Am Soc Echocardiogr. 1995;8(5 Pt 1):756–8. 61. Topol EJ, Biern RO, Reitz BA. Cardiac papillary fibroelastoma and stroke. Echocardiographic diagnosis and guide to excision. Am J Med. 1986;80(1):129–32. 62. Bowen TE, Tri TB, Wortham DC. Thrombosis of a St. Jude Medical tricuspid prosthesis. Case report. J Thorac Cardiovasc Surg. 1981;82(2):257–62. 63. Ngaage DL, Mullany CJ, Daly RC, et al. Surgical treatment of cardiac papillary fibroelastoma: a single center experience with eighty-eight patients. Ann Thorac Surg. 2005;80(5):1712–8. 64. Pothineni KR, Duncan K, Yelamanchili P, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: incremental value over the two-dimensional technique. Echocardiography. 2007;24(5):541–52. 65. Sun JP, Asher CR, Yang XS, et al. Clinical and echocardiographic characteristics of papillary fibroelastomas: a retrospective and prospective study in 162 patients. Circulation. 2001;103(22):2687–93. 66. Altbach MI, Squire SW, Kudithipudi V, et al. Cardiac MRI is complementary to echocardiography in the assessment of cardiac masses. Echocardiography. 2007;24(3):286–300. 67. Hicks KA, Kovach JA, Frishberg DP, et al. Echocardiographic evaluation of papillary fibroelastoma: a case report and review of the literature. J Am Soc Echocardiogr. 1996; 9(3):353–60. 68. Uchida S, Obayashi N, Yamanari H, et al. Papillary fibroelastoma in the left ventricular outflow tract. Heart Vessels. 1992;7(3):164–7. 69. Salcedo EE, Cohen GI, White RD, et al. Cardiac tumors: diagnosis and management. Curr Probl Cardiol. 1992; 17(2):73–137. 70. Braile DM, Rossi MA, Jacob JL, et al. Cystic fibroelastoma of the mitral valve: report of a case. J Thorac Cardiovasc Surg. 1993;106(6):1228–30. 71. Thomas MR, Jayakrishnan AG, Desai J, et al. Transesophageal echocardiography in the detection and surgical management of a papillary fibroelastoma of the mitral valve causing partial mitral valve obstruction. J Am Soc Echocardiogr. 1993;6(1):83–6. 72. Le Tourneau T, Pouwels S, Gal B, et al. Assessment of papillary fibroelastomas with live three-dimensional transthoracic echocardiography. Echocardiography. 2008; 25(5):489–95.

73. Araoz PA, Mulvagh SL, Tazelaar HD, et al. CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation. Radiographics. 2000; 20(5):1303–19. 74. Parmley LF, Salley RK, Williams JP, et al. The clinical spectrum of cardiac fibroma with diagnostic and surgical considerations: noninvasive imaging enhances management. Ann Thorac Surg. 1988;45(4):455–65. 75. de Ruiz M, Potter JL, Stavinoha J, et al. Real time ultrasound diagnosis of cardiac fibroma in a neonate. J Ultrasound Med. 1985;4(7):367–9. 76. Parthenakis F, Nyktari E, Patrianakos A, et al. Asymptomatic papillary fibroelastoma of the aortic valve in a young woman—a case report. Cardiovasc Ultrasound. 2009;7:43. 77. Robert-Ebadi H, Le Gal G, Righini M. Use of anticoagulants in elderly patients: practical recommendations. Clin Interv Aging. 2009;4:165–77. 78. Pinelli G, Carteaux JP, Mertes PM, et al. Mitral valve tumor revealed by stroke. J Heart Valve Dis. 1995;4(2):199–201. 79. Silverman NA. Primary cardiac tumors. Ann Surg. 1980;191(2):127–38. 80. Sakata K, Ohtaki A, Aiba M, et al. Left ventricular fibroma in an aged patient: report of a case. Surg Today. 1997;27(1):88–9. 81. Iqbal MB, Stavri G, Mittal T, et al. A calcified cardiac mass. Int J Cardiol. 2007;115(3):e126–e128. 82. Geha AS, Weidman WH, Soule EH, et al. Intramural ventricular cardiac fibroma. Successful removal in two cases and review of the literature. Circulation. 1967;36(3):427–40. 83. Reece IJ, Houston AB, Pollock JC. Interventricular fibroma. Echocardiographic diagnosis and successful surgical removal in infancy. Br Heart J. 1983;50(6):590–1. 84. Takahashi K, Imamura Y, Ochi T, et al. Echocardiographic demonstration of an asymptomatic patient with left ventricular fibroma. Am J Cardiol. 1984;53(7):981–2. 85. Dobrilovic N, Singh AK, LeGolvan M, et al. Massive cardiac fibroma. J Card Surg. 2011;26(2):159–61. 86. Albaghdadi MS, Popescu A, Davidson CJ, et al. Adult cardiac fibroma. J Am Coll Cardiol. 2012;59(8):e15. 87. Uzun O, Wilson DG, Vujanic GM, et al. Cardiac tumours in children. Orphanet J Rare Dis. 2007;2:11. 88. Nadas AS, Ellison RC. Cardiac tumors in infancy. Am J Cardiol. 1968;21(3):363–6. 89. Bittner HB, Sharma AD, Landolfo KP. Surgical resection of an intracardiac rhabdomyoma. Ann Thorac Surg. 2000;70(6):2156–8. 90. Miyake CY, Del Nido PJ, Alexander ME, et al. Cardiac tumors and associated arrhythmias in pediatric patients, with observations on surgical therapy for ventricular tachycardia. J Am Coll Cardiol. 2011;58(18):1903–9. 91. Shaher RM, Mintzer J, Farina M, et al. Clinical presentation of rhabdomyoma of the heart in infancy and childhood. Am J Cardiol. 1972;30(1):95–103. 92. Kaushik SK, Bhargava K, Kaushik A. Cardiac rhabdomyoma with LVOT obstruction and anorectal malformation in a neonate: a rare association. Indian Heart J. 2012;64(5): 508–10.


93. Haydin S, Onan B, Kiplapinar N, et al. Combined resection and radiofrequency ablation of rhabdomyoma in a child with sustained ventricular tachycardia. J Card Surg. 2012; 27(5):649–52. 94. Farooki ZQ, Ross RD, Paridon SM, et al. Spontaneous regression of cardiac rhabdomyoma. Am J Cardiol. 1991; 67(9):897–9. 95. Olsen RE, Tangchai P. Large lipoma of the left ventricle. Arch Pathol. 1961;72:290–6. 96. Behnam R, Williams G, Gerlis L, et al. Lipoma of the mitral valve and papillary muscle. Am J Cardiol. 1983;51(8): 1459–60. 97. Fyke FE 3rd, Tajik AJ, Edwards WD, et al. Diagnosis of lipomatous hypertrophy of the atrial septum by twodimensional echocardiography. J Am Coll Cardiol. 1983; 1(5):1352–7. 98. Schiettecatte A, Verdries D, de Mey J, et al. Magnetic resonance imaging findings in cardiac lipoma. JBR-BTR. 2012;95(5):300–1. 99. Tabry IF, Nassar VH, Rizk G, et al. Cavernous hemangioma of the heart: case report and review of the literature. J Thorac Cardiovasc Surg. 1975;69(3):415–20. 100. Riggs T, Paul MH, DeLeon S, et al. Two dimensional echocardiography in evaluation of right atrial masses: five cases in pediatric patients. Am J Cardiol. 1981;48(5):961–6. 101. Novitzky D, Rose AG, Morgan JA, et al. Primary cardiac haemangiomas. A report of 2 cases. S Afr Med J. 1984; 66(7):267–70. 102. Boden WE, Funk EJ, Carleton RA, et al. Left ventricular hemangioma masquerading as Mycoplasma pericarditis. Am Heart J. 1983;106(4 Pt 1):771–4. 103. Palmer TE, Tresch DD, Bonchek LI. Spontaneous resolution of a large, cavernous hemangioma of the heart. Am J Cardiol. 1986;58(1):184–5. 104. McAllister HA, Fenoglio, JJ. Tumors of the cardiovascular system. In: W. Hartmann, W.R. Cowan, (Editors). Atlas of Tumor Pathology. U.S. Armed Forces Institute of Pathology: Washington DC; 1978:40–6. 105. Shapiro LM. Cardiac tumours: diagnosis and management. Heart. 2001;85(2):218–22. 106. Amonkar GP, Deshpande JR. Cardiac angiosarcoma. Cardiovasc Pathol. 2006;15(1):57–8. 107. Brandt RR, Arnold R, Bohle RM, et al. Cardiac angiosarcoma: case report and review of the literature. Z Kardiol. 2005;94(12):824–8. 108. Singh A, Pothineni KR, Panwar SR. Left ventricular mass assessment by real time three-dimensional echocardiography. Am J Cardiol. 2007;99(8):1180–1. 109. Lepper W, Shivalkar B, Rinkevich D, et al. Assessment of the vascularity of a left ventricular mass using myocardial contrast echocardiography. J Am Soc Echocardiogr. 2002;15(11):1419–22. 110. Miller AP, Nanda NC. Contrast echocardiography: new agents. Ultrasound Med Biol. 2004;30(4):425–34. 111. Burke AP, Cowan D, Virmani R. Primary sarcomas of the heart. Cancer. 1992;69(2):387–95.

1521

112. Rettmar K, Stierle U, Sheikhzadeh A, et al. Primary angiosarcoma of the heart. Report of a case and review of the literature. Jpn Heart J. 1993;34(5):667–83. 113. Bear PA, Moodie DS. Malignant primary cardiac tumors. The Cleveland Clinic experience, 1956 to 1986. Chest. 1987;92(5):860–2. 114. Neragi-Miandoab S, Kim J, Vlahakes GJ. Malignant tumours of the heart: a review of tumour type, diagnosis and therapy. Clin Oncol (R Coll Radiol). 2007;19(10):748–56. 115. Bruce CJ. Cardiac tumours: diagnosis and management. Heart. 2011;97(2):151–60. 116. Satou Y, Nakagawa Y, Miki H, et al. Cardiac angiosarcoma with ruptured right atrium diagnosed by echocardiography. Chest. 1991;100(1):274–5. 117. Bruna J, Lockwood M. Primary heart angiosarcoma detected by computed tomography and magnetic resonance imaging. Eur Radiol. 1998;8(1):66–8. 118. Lee CH, Chan GS, Chan WM. Unexplained recurrent pericardial effusion: a lethal warning? Heart. 2003;89(3):e11. 119. Janigan DT, Husain A, Robinson NA. Cardiac angiosarcomas. A review and a case report. Cancer. 1986;57(4):852–9. 120. Castorino F, Masiello P, Quattrocchi E, et al. Primary cardiac rhabdomyosarcoma of the left atrium: an unusual presentation. Tex Heart Inst J. 2000;27(2):206–8. 121. Lima Rde C, Mendes A, Bezerra E, et al. Surgical treatment of primary cardiac rhabdomyosarcoma. Rev Bras Cir Cardiovasc. 2009;24(2):242–4. 122. Bouzas-Mosquera A, Flores-Rios X, Aldama G. Primary cardiac rhabdomyosarcoma causing obstruction to the right ventricular outflow. Eur J Echocardiogr. 2007;8(5):406–7. 123. Araoz PA, Eklund HE, Welch TJ, et al. CT and MR imaging of primary cardiac malignancies. Radiographics. 1999;19(6):1421–34. 124. Villacampa VM, Villarreal M, Ros LH, et al. Cardiac rhabdomyosarcoma: diagnosis by MR imaging. Eur Radiol. 1999;9(4):634–7. 125. Stakos DA, Xatseras DI, Boudoulas H. Cardiac lymphoma. Eur Heart J. 2006;27(13):1538. 126. Chim CS, Chan AC, Kwong YL, et al. Primary cardiac lymphoma. Am J Hematol. 1997;54(1):79–83. 127. Hsueh SC, Chung MT, Fang R, et al. Primary cardiac lymphoma. J Chin Med Assoc. 2006;69(4):169–74. 128. Ceresoli GL, Ferreri AJ, Bucci E, et al. Primary cardiac lymphoma in immunocompetent patients: diagnostic and therapeutic management. Cancer. 1997;80(8):1497–506. 129. Aboulafia DM, Bush R, Picozzi VJ. Cardiac tamponade due to primary pericardial lymphoma in a patient with AIDS. Chest. 1994;106(4):1295–9. 130. Balasubramanyam A, Waxman M, Kazal HL, et al. Malignant lymphoma of the heart in acquired immune deficiency syndrome. Chest. 1986;90(2):243–6. 131. Gill PS, Chandraratna PA, Meyer PR, et al. Malignant lymphoma: cardiac involvement at initial presentation. J Clin Oncol. 1987;5(2):216–24. 132. Ikeda H, Nakamura S, Nishimaki H, et al. Primary lymphoma of the heart: case report and literature review. Pathol Int. 2004;54(3):187–95.

1522


133. Rolla G, Bertero MT, Pastena G, et al. Primary lymphoma of the heart. A case report and review of the literature. Leuk Res. 2002;26(1):117–20. 134. Tai CJ, Wang WS, Chung MT, et al. Complete atrioventricular block as a major clinical presentation of the primary cardiac lymphoma: a case report. Jpn J Clin Oncol. 2001;31(5):217–20. 135. Ito M, Tsuchiyama J, Chinushi M, et al. Images in cardiovascular medicine. Transient giant negative T waves associated with cardiac involvement of diffuse large B-cell lymphoma. Circulation. 2005;112(20):e322–e323. 136. Horowitz MD, Cox MM, Neibart RM, et al. Resection of right atrial lymphoma in a patient with AIDS. Int J Cardiol. 1992;34(2):139–42. 137. Duong M, Dubois C, Buisson M, et al. Non-Hodgkin’s lymphoma of the heart in patients infected with human immunodeficiency virus. Clin Cardiol. 1997;20(5):497–502. 138. Helfand J. Cardiac tamponade as a result of American Burkitt’s lymphoma of the heart and pericardium. Conn Med. 1990;54(4):186–9. 139. Hoffmann U, Globits S, Frank H. Cardiac and paracardiac masses. Current opinion on diagnostic evaluation by magnetic resonance imaging. Eur Heart J. 1998;19(4): 553–63. 140. Torstveit JR, Bennett WA, Hinchcliffe WA, et al. Primary plasmacytoma of the atrium. Report of a case with successful surgical management. J Thorac Cardiovasc Surg. 1977;74(4):563–6. 141. Carrel T, Linka A, Turina MI. Tricuspid valve obstruction caused by plasmacytoma metastasis. Ann Thorac Surg. 1992;54(2):352–4. 142. Thameur H, Abdelmoula S, Chenik S, et al. Cardiopericardial hydatid cysts. World J Surg. 2001;25(1):58–67. 143. Gössinger HD, Siostrzonek P, Zangeneh M, et al. Magnetic resonance imaging findings in a patient with pericardial mesothelioma. Am Heart J. 1988;115(6):1321–2. 144. Rizzardi C, Barresi E, Brollo A, et al. Primary pericardial mesothelioma in an asbestos-exposed patient with previous heart surgery. Anticancer Res. 2010;30(4):1323–5. 145. Quinn DW, Qureshi F, Mitchell IM. Pericardial mesothelioma: the diagnostic dilemma of misleading images. Ann Thorac Surg. 2000;69(6):1926–7. 146. Ost P, Rottey S, Smeets P, et al. F-18 fluorodeoxyglucose PET/CT scanning in the diagnostic work-up of a primary pericardial mesothelioma: a case report. J Thorac Imaging. 2008;23(1):35–8. 147. Ohnishi J, Shiotani H, Ueno H, et al. Primary pericardial mesothelioma demonstrated by magnetic resonance imaging. Jpn Circ J. 1996;60(11):898–900. 148. Bussani R, De-Giorgio F, Abbate A, et al. Cardiac metastases. J Clin Pathol. 2007;60(1):27–34. 149. Prichard RW. Tumors of the heart; review of the subject and report of 150 cases. AMA Arch Pathol. 1951;51(1):98– 128.

150. Bisel HF, Wroblewski F, Ladue JS. Incidence and clinical manifestations of cardiac metastases. J Am Med Assoc. 1953;153(8):712–15. 151. Young JM, Goldman IR. Tumor metastasis to the heart. Circulation. 1954;9(2):220–9. 152. Klatt EC, Heitz DR. Cardiac metastases. Cancer. 1990; 65(6):1456–9. 153. Lockwood WB, Broghamer WL Jr. The changing prevalence of secondary cardiac neoplasms as related to cancer therapy. Cancer. 1980;45(10):2659–62. 154. Lam KY, Dickens P, Chan AC. Tumors of the heart. A 20-year experience with a review of 12,485 consecutive autopsies. Arch Pathol Lab Med. 1993;117(10):1027–31. 155. Glancy DL, Roberts WC. The heart in malignant melanoma. A study of 70 autopsy cases. Am J Cardiol. 1968;21(4): 555–71. 156. Johnson MH, Soulen RL. Echocardiography of cardiac metastases. AJR Am J Roentgenol. 1983;141(4):677–81. 157. Kutalek SP, Panidis IP, Kotler MN, et al. Metastatic tumors of the heart detected by two-dimensional echocardiography. Am Heart J. 1985;109(2):343–9. 158. Engberding R, Daniel WG, Erbel R, et al. Diagnosis of heart tumours by transoesophageal echocardiography: a multicentre study in 154 patients. European Cooperative Study Group. Eur Heart J. 1993;14(9):1223–8. 159. Yelamanchili P, Wanat FE, Knezevic D, et al. Twodimensional transthoracic contrast echocardiographic assessment of metastatic left ventricular tumors. Echocardiography. 2006;23(3):248–50. 160. Pellikka PA, Tajik AJ, Khandheria BK, et al. Carcinoid heart disease. Clinical and echocardiographic spectrum in 74 patients. Circulation. 1993;87(4):1188–96. 161. Hellerstein HK, Orbison JL. Anatomic variations of the orifice of the human coronary sinus. Circulation. 1951;3(4):514–23. 162. Mak GS, Hill AJ, Moisiuc F, et al. Variations in Thebesian valve anatomy and coronary sinus ostium: implications for invasive electrophysiology procedures. Europace. 2009;11(9):1188–92. 163. Pejkovic B, Krajnc I, Anderhuber F, et al. Anatomical variations of the coronary sinus ostium area of the human heart. J Int Med Res. 2008;36(2):314–21. 164. Pearson AC, Labovitz AJ, Tatineni S, et al. Superiority of transesophageal echocardiography in detecting cardiac source of embolism in patients with cerebral ischemia of uncertain etiology. J Am Coll Cardiol. 1991;17(1):66–72. 165. Kurt M, Shaikh KA, Peterson L, et al. Impact of contrast echocardiography on evaluation of ventricular function and clinical management in a large prospective cohort. J Am Coll Cardiol. 2009;53(9):802–10. 166. Mügge A, Daniel WG, Frank G, et al. Echocardiography in infective endocarditis: reassessment of prognostic implications of vegetation size determined by the transthoracic and the transesophageal approach. J Am Coll Cardiol. 1989;14(3):631–8.


167. Evangelista A, Gonzalez-Alujas MT. Echocardiography in infective endocarditis. Heart. 2004;90(6):614–7. 168. Shapiro SM, Young E, De Guzman S, et al. Transesophageal echocardiography in diagnosis of infective endocarditis. Chest. 1994;105(2):377–82. 169. Shively BK, Gurule FT, Roldan CA, et al. Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis. J Am Coll Cardiol. 1991;18(2):391–7. 170. San Román JA, Vilacosta I, Zamorano JL, et al. Transesophageal echocardiography in right-sided endocarditis. J Am Coll Cardiol. 1993;21(5):1226–30. 171. Klug D, Lacroix D, Savoye C, et al. Systemic infection related to endocarditis on pacemaker leads: clinical presentation and management. Circulation. 1997;95(8):2098–107. 172. Veinot JP, Tazelaar HD, Edwards WD, et al. Mesothelial/ monocytic incidental cardiac excrescences: cardiac MICE. Mod Pathol. 1994;7(1):9–16. 173. Censi S, Dell’Amore A, Conti R, et al. Cardiac mesothelial/ monocytic-incidental-excrescence: more than an artifactual lesion? Interact Cardiovasc Thorac Surg. 2008;7(6):1201–3.

1523

174. Deluca G, Correale M, Ieva R, et al. The incidence and clinical course of caseous calcification of the mitral annulus: a prospective echocardiographic study. J Am Soc Echocardiogr. 2008; 21(7):828–33. 175. Reynolds C, Tazelaar HD, Edwards WD. Calcified amorphous tumor of the heart (cardiac CAT). Hum Pathol. 1997;28(5):601–6. 176. Lewin M, Nazarian S, Marine JE, et al. Fatal outcome of a calcified amorphous tumor of the heart (cardiac CAT). Cardiovasc Pathol. 2006; 15(5):299–302. 177. Habib A, Friedman PA, Cooper LT, et al. Cardiac calcified amorphous tumor in a patient presenting for ventricular tachycardia ablation: intracardiac echocardiogram diagnosis and management. J Interv Card Electrophysiol. 2010;29(3):175–8. 178. Chan J, Manning WJ, Appelbaum E, et al. Large hiatal hernia mimicking left atrial mass: a multimodality diagnosis. J Am Coll Cardiol. 2009;54(6):569. 179. Plehn J, Sager J, Foster E, et al. Pericardial pseudotumor. Echocardiographic observation of juxtacardiac pulmonary collapse. Chest. 1988;94(4):837–41.

SECTION 6 Congenital Heart Disease

Chapters Chapter 71 Fetal Cardiac Imaging Chapter 72 M-Mode and Two-Dimensional Echocardiography in Congenital Heart Disease Chapter 73 Real time 3D Echocardiography for Quantification of Ventricular Volumes, Mass and Function in Children with Congenital and Acquired Heart Diseases

Chapter 74 Three-Dimensional Echocardiography in Congenital Heart Disease Chapter 75 Echocardiography in the Evaluation of Adults with Congenital Heart Disease Chapter 76 Echocardiographic Evaluation for Acquired Heart Diseases in Childhood

1527

CHAPTER 71 Fetal Cardiac Imaging Aarti H Bhat

Snapshot  Scope of Fetal Cardiology  IndicaƟons for Fetal Cardiac EvaluaƟon  Fetal Physiology  IndicaƟons for Fetal Echocardiography

INTRODUCTION The field of fetal cardiology has made significant advances along with all aspects of prenatal evaluation over the last three decades. Almost all structural fetal heart disease is amenable to a detailed in utero diagnosis that can then be used to develop plans for fetal as well as postnatal management of a pregnancy. Fetal ultrasound and twodimensional imaging are central to this diagnostic process. Improvements in ultrasound techniques as well as our enhanced understanding of fetal cardiac anatomy and physiology have facilitated and broadened the scope of this specialty. The purpose of this chapter is to familiarize the reader with the basic framework of fetal cardiology using a basic description of echocardiographic anatomy. Liberal use of illustrative labeled screen images as well as movie clips (on-line version) are intended to orient the reader as well as provide an example of the anatomical defect or finding being discussed.

SCOPE OF FETAL CARDIOLOGY Cardiac malformations occur in 4 to 8/1,000 live births and account for one-third of perinatal mortality due to congenital anomalies.1–3 In the low-risk general population, an obstetric scan using the four-chamber and

 Extracardiac Reasons and AssociaƟons for Fetal Heart

Disease  Fundamentals of Fetal Cardiac Imaging  Case Studies

outflow views yields a sensitivity of 52 to 92% in detecting congenital heart defects. The range is similar in highrisk populations. A fetal echocardiogram (traditionally acquired if the screening ultrasound is positive and/or in high-risk pregnancies) has a sensitivity of 42 to 100% for detection of congenital heart disease.4–11 Over the years, many studies have proven aspects of improved survival or decreased morbidity in groups of newborns that have received a prenatal cardiac diagnosis that translates into a specific birth plan and postnatal management including emergent neonatal intervention.12–17 Identification of critical heart disease can allow in utero surveillance culminating in therapy in the form of maternal medications, fetal cardiac intervention, and a heightened awareness of immediate requirements in the delivery room or soon after.18,19 Despite the presence of the need for prenatal diagnosis and the presence of robust tools to achieve this, the overall rate of prenatal detection by routine obstetric scan is unfortunately low.20–22 Heart defects in a fetus may be “isolated” if there is no other organ or genetic abnormalities or “associated” with other organ anomalies or genetic problems. Determining a possible abnormality in fetal life allows for a more detailed evaluation of the other organ systems, fetal growth and well-being, and chromosomal disorders. Such

1528

Section 6: Congenital Heart Disease

a process may lead to an overall complete fetal diagnosis, allowing the involved teams to plan a process of pregnancy management. Practice care models are unique to each institution and vary greatly depending on the setting (primary vs. tertiary), specialty (obstetric, pediatric, or combined) or skill and resource level (screening center or referral center). There are potentially many good and appropriate ways to achieve the endpoints of prenatal cardiac care, which are (a) as accurate and complete a diagnosis as possible; (b) a complete, fact-driven, and compassionate counseling; and (c) securing a safe birth and transition plan for the maternal–fetal dyad and the newborn. This chapter is aimed at providing the reader with a good understanding of the first necessary undertaking of anatomical diagnosis. Prenatal counseling is very stressful on the parents for whom the hope and prospect of a normal baby is now changed. A genuine compassionate and honest approach to the interview session needs to secure their understanding and trust, as the whole team establishes common goals. Parental grief, stress, and depression need to be acknowledged as these are known to continue from the prenatal to the postnatal periods.23

INDICATIONS FOR FETAL CARDIAC EVALUATION A screening obstetric ultrasound at about 18 to 20 weeks is usually performed in most obstetric programs. The primary aim of this scan is to acquire all pertinent fetal and uteroplacental information in a particular pregnancy. An abnormal fetal cardiac or extracardiac scan at this gestation as well as a suspected or proven chromosomal anomaly prompts a fetal cardiac evaluation and is the single most robust source for fetal cardiac pathology. The vast majority of these patients do not have any of the risk factors typically considered as “high risk.” Pregnancies considered at “high risk” for fetal cardiac and noncardiac pathologies are the dominant cause for referral to the fetal cardiologist, but, the relative yield of abnormal fetal cardiac exams is relatively lower from this indication group. This brings up an interesting aspect while planning a fetal cardiac program aiming to increase prenatal diagnosis rates in that most of the abnormal fetal heart diagnoses actually come from a “low-risk” group. This fact implies that any increase in fetal cardiac diagnosis over a population can only come from an improvement in the obstetric “screening” scan. Improving the awareness of obstetric sonographers, close attention to and low threshold for

referral if there are concerning or unusual findings, and improved access to fetal cardiologists are each a key step in overall improvement in the rates of prenatal diagnosis of fetal heart defects. Critical congenital heart disease such as atresias of the atrioventricular valve with or without accompanying hypoplastic ventricles, cardiac dysfunction, and pericardial effusion are amenable to detection from a four-chamber view. However, other critical diseases such as transposition of the great arteries and semilunar valve hypoplasia/atresia can only be detected if biventricular outflow view can be obtained. The parallel orientation of the great arteries can be easily determined in the outflow view even if the four-chamber view indicated no obvious abnormality [for example, in a dextro Transposition of great arteries (dTGA) without ventricular septal defect (VSD)]. Nuchal translucency (NT) detects the echo-free space at the back of the neck, typically measures at 11 to 14 weeks of gestation. Increased NT (typically > 4 mm) is strongly associated with abnormal chromosomes, with or without congenital heart disease.24,25 Often times, at this stage, with or without a confirmed diagnosis of fetal aneuploidy depending on when and if the parents and providers are proceeding with an amniocentesis or chorionic villus biopsy (CVS), the pregnancy is referred for a fetal cardiac evaluation. Even in the absence of confirmed aneuploidy, elevated fetal NT in the first trimester and other “soft markers” such as intracardiac echogenic focus (IEF) and intrauterine growth retardation (IUGR) or extracardiac pathology may be indications for fetal echocardiography.

FETAL PHYSIOLOGY Fetal circulation appears uniquely adapted to maximize efficiency and oxygen delivery. Some of the most exhaustive information on fetal physiology was originally derived from fetal sheep.26 Similar data from the human fetus is incomplete. Oxygenated blood is delivered to the fetus through the umbilical vein. This vein enters the porta hepatis and gives several branches to the left lobe of the liver, distal to these is the ductus venosus. The umbilical veins then arches toward the right lobe of the liver, is joined there by the portal vein, and gives branches to the right lobe of the liver. The ductus venosus then continues on and connects to the inferior vena cava, as do the left hepatic veins. Flow from the ductus venosus is preferentially directed by the Eustachian valve, across the foramen ovale to the left atrium. Nearly the entire return from the superior vena cava enters the right ventricle through the tricuspid valve.27–31 Right ventricular output

Chapter 71: Fetal Cardiac Imaging

[55% of the combined biventricular output (CVVO)] is directed across the pulmonary valve, most of this enters the ductus arteriosus, and joins the aortic arch at the isthmus. Just under 20% of the combined cardiac output enters the pulmonary bed through the pulmonary arteries and returns to the left atrium. Left ventricular output (45% of the CVVO) is directed across the aortic valve to the ascending aorta. Most of this amount flows to the coronary arteries, and the head and neck vessels, so that only 10% of the CVVO actually crosses the isthmus, the region of the distal aortic arch between the origins of the left subclavian and the insertion of the ductus arteriosus. The aortic and ductal arches merge, and the descending aorta carries supply to the abdominal organs and then to the umbilical artery, headed to the placenta. In this manner, the entire umbilical venous flow is returned to the umbilical arterial side. The CVVO in the fetus is about 450 mL/min/kg of estimated fetal weight and the right:left ventricular output ratio is about 1.2 to 1.3.32,33 CVVO is determined by heart rate and stroke volume, and the latter is determined by preload and afterload, very similar to the physiological inter-relationships seen in children and adults. However, fetal myocardium generates less tension at similar muscle lengths as compared to adult myocardium and there may be differences in the sarcoplasmic reticulum as well as calcium uptake function.34,35 In the fetus, the two natural right–left communications at the level of the foramen ovale and the ductus arteriosus allow equalization of the right and left pressures at the atrial and great arterial levels. The left ventricular–aortic output upto and including the aortic isthmus is likely a higher afterload as compared to the right ventricular– pulmonary trunk output that has a higher compliance placental bed distally.

INDICATIONS FOR FETAL ECHOCARDIOGRAPHY Maternal Indications Family History of Congenital Heart Disease Family history of transmissible genetic malformations that have known cardiac abnormality such as 22q11 deletion syndromes, Marfan or Noonan syndrome as well as multifactorial-etiology type defects such as ventricular septal defect or bicuspid aortic valve-hypoplastic left heart syndrome spectrum in first order relatives is an indication

1529

for fetal echocardiography. Maternal metabolic disorders such as diabetes and phenylketonuria are known to increase the risk for congenital cardiac defects. Maternal diabetes in particular has been the cause of much controversy in terms of screening recommendations.36–40 The incidence of fetal cardiac defects is noted to be as much as five time higher than euglycemic pregnancies and worsens with HbA1c levels > 6.3% in the first trimester. Existing strategies are based on resource utilization models (comprehensive fetal obstetric ultrasound in the pregestational diabetic population, followed by fetal cardiac referral in the presence of concerning findings) or risk-based models (risk increases with elevated HbA1c levels).41 Maternal autoimmune disease such as Sjogren syndrome or systemic lupus erythematosus has an increased incidence of fetal congenital complete heart block (CCHB) that can be detected as well as monitored by fetal echo and for which therapeutic options exist.42 Maternal teratogen exposure, for example, alcohol, lithium, retinoic acid anticonvulsants, and SSRI antidepressant have noted increase in fetal cardiac and extracardiac malformations. Maternal and intrauterine infections such as congenital rubella and coxsackie virus can be seen with cardiac defects. The use of in vitro fertilization or other reproductive assist techniques are being increasingly recognized with elevated rate of congenital cardiac malformations. Fetal indications such as a fetal heart abnormality suspected on a screening obstetric ultrasound, extracardiac structural abnormalities, single umbilical artery, chromosomal abnormalities—confirmed or suspected— fetal arrhythmia, multiple gestations, and fetal nonimmune hydrops.

EXTRACARDIAC REASONS AND ASSOCIATIONS FOR FETAL HEART DISEASE Twin gestations can have unique cardiovascular findings, more common in monochorionic gestations. Twin–twin transfusion syndrome (TTTS) can occur due to abnormal placental vascular connections in about 15% of monochorionic twin pregnancies, increasingly seen due to more widespread use of reproductive technologies.43 There is discordance in fetal size. The recipient twin is larger, has polyhydramnios, cardiomegaly, biventricular hypertrophy and dysfunction, and atrioventricular valve incompetence. In approximately 10%, there is acquired

1530


right ventricular outflow tract obstruction, pulmonary stenosis, and even reversal of ductal flow.44,45 Eventually, recipient cardiomyopathy from systolic as well as diastolic dysfunction can lead to hydrops and fetal demise. The donor twin, on the other hand, is likely to have a structurally and functionally normal heart, evidence of elevated placental vascular resistance, relative hypovolemia, and oligohydramnios. Scoring systems are used to gauge disease severity.46,47 Laser photocoagulation of the placental vascular connections is currently the treatment of choice for TTTS.48 The abnormal cardiovascular findings can improve after this therapy, although complete normalization is unlikely in the subgroup that has developed anatomical pulmonary atresia.49 Twin reverse arterial perfusion (TRAP) occurs in 1% of monochorionic pregnancies, in which one twin is acardiac with a primitive or nonfunctional heart. The normal twin heart pumps blood through superficial arterial–arterial placental anastomosis to this acardiac twin. As a result, the direction of flow in the umbilical artery of the acardiac– acephalic twin is from placenta to fetus (reversed). Serially evaluating the combined cardiac output of the normal twin can monitor for the increased cardiovascular workload to this heart, which can culminate in heart failure, hydrops, and demise.50 Congenital cystic adenomatoid malformation (CCAM) is a rare developmental abnormality of the lung due to overgrowth of the terminal bronchioles, causing a dysplastic lung mass. This mass can cause compression of the developing fetal heart, alter its position within the thorax, alter the angulation of the inferior vena cava as it enters the displaced heart, decrease cardiac filling, and potentially lead to fetal hydrops. Due to the increased intrathoracic pressure from the lung mass, hydrops is not typically accompanied by pleural or pericardial effusions.51 Congenital diaphragmatic hernia (CDH) is a defect in the muscular diaphragm between the chest and abdominal cavities. Abdominal contents can herniate through this defect and occupy space in the chest, causing varying degrees of displacement and extrinsic compression to the heart and lungs. Since this process happens in early gestation, the presence of herniated contents can adversely and proportionately impact the development of lung parenchyma as well as vasculature causing pulmonary hypoplasia. CDH can occur along with structural heart disease as part of a syndrome (e.g. Wolf– Hirschhorn syndrome, trisomy 18, vitamin A exposure), the commonest being ventricular septal defect. Curiously, a decrease in left ventricular wall as well as cavity

dimensions is also noted, possibly due to decreased filling, but may also eventuate in obstructive left-sided lesions. Sacrococcygeal teratoma is a pluripotential tumor arising from the sacrococcygeal region. This is the commonest tumor seen in the fetus, albeit rare and its major cardiac impact is to cause high-output heart failure and hydrops in the fetus. Serial evaluation of the CVVO is indicated to decide on need and timing for fetal intervention in the form of a cyst aspiration, laparoscopic laser ablation, surgical debulking, or early delivery.

FUNDAMENTALS OF FETAL CARDIAC IMAGING Two-dimensional imaging is the principal imaging modality for fetal heart disease detection. Basic ultrasound principles apply to fetal imaging, although with many additional levels of technical challenges as well as opportunities. In general, a combination of obstetric and pediatric cardiology skills is required. Flexibility, familiarity as well as perseverance are essential to get as complete and accurate a fetal cardiac examination as possible. The small size of fetal cardiac structures as well as the relatively faster fetal heart rate can challenge the spatial as well as temporal resolution capabilities of the ultrasound system. Accordingly, a higher frequency transducer, minimal distance between the fetal heart and the transducer on the maternal abdomen, appropriate depth and width of the region of interest, and dynamic focusing are all important considerations and need to be optimized. Since axial resolution typically exceeds radial resolution, the transducer can be moved on the maternal abdomen so as to insonate the region of interest at minimal angulation. Similar to the pediatric cardiac exam, each region of interest needs to be seen in multiple views to get an accurate impression. Again, similar to a pediatric cardiac exam, a segmental completeness is necessary. Fetal position, movement, and variable transducer positions make this a literal moving target and while a protocolized progression of sweeps and views cannot be realistically applied, every attempt should be made to demonstrate as many anatomical and functional components of each segment. A lower frequency transducer, even a nonobstetric one may be occasionally helpful in a later trimester gestation, where more penetration is required. This strategy may also be required in the rare event of an aliasing Doppler signal with the usual obstetric transducer. Harmonic imaging may enhance the blood–tissue interface and permit better assessment in some challenging cases. In early


gestation and while the pregnancy is still pelvic, the use of endovaginal transducers can permit the best resolution studies in the first trimester and may add information to transabdominal scans.52,53 Guidelines have been published for the “basic” and “extended basic” fetal cardiac scan and the reader intending to formalize a fetal echo protocol is encouraged to read them.54,55 By convention, the transducer notch is always pointing toward the maternal left side. Even as multiple sweeps will require clockwise and anticlockwise rotation, it is important to keep in mind that the notch must be kept in the left two quadrants to avoid confusion. The left/right invert button may allow better pattern recognition in some situations and readers, but, overall, inadvertent switching can cause tremendous errors in situs assessments and should be avoided or vigilantly supervised. A fetal cardiac exam must begin with knowledge of the fetal indication, obstetric findings, and other concerning extracardiac anatomical findings in the fetus. The key elements are quite comprehensive and include assessment of the fetal number and position in the uterus. Determining the abdominal and cardiac situs needs to be established at the very beginning of the study. This can be done by establishing the fetal presentation followed by the fetal left and right side—the use of a doll to illustrate the relative location of a fetus in the uterus is often helpful to interpret a uniplanar display. Another method that has been used requires the fetal scan to demonstrate the fetal head to the right of the screen. From this position, a 90° rotation of the transducer will bring the fetal heart into a cross-sectional view. Levocardia is interpreted from a fetal heart and apex that are located and directed to the right of the fetal spine in this position.56 Ideally, the fetal cardiologist should be able to interpret both methods and even use both in each case as a mechanism for cross checking. As part of this situs sweep, the location of the heart and stomach on the left, and inferior vena cava on the right establishes abdominal as well as cardiac situs. The position of the heart within the fetal chest may itself indicate potential abnormality if it is located in the right chest, apex is pointed to the right side of the fetus, or if the cardiac axis is abnormal. The fetal cardiac axis is the angle between the plane of the interventricular septum and the presumed midline and has been noted to be 43 ± 7.57 The cardiothoracic area should be under 40%— a relatively larger heart occurs in cardiac lesions such as Ebstein’s anomaly and a relatively larger lung component is noted in severe pulmonary cystic lesions. The following views comprise a complete exam, although of course they may not be acquired in this order and may be incomplete

1531

Fig. 71.1: Cardiac situs, cardiothoracic ratio, and cardiac axis determination. Fetal cardiology consult was requested due to older sibling with tricuspid atresia. Gestational age is 28 3/7 weeks. In the Cordes technique demonstrated, the fetal position within the uterus is determined and a short axis of the fetal chest is obtained with the fetal head on the right of the screen. Fetal heart and cardiac apex to the right of the fetal spine in this technique indicate levocardia. Situs can also be cross-checked with the second technique demonstrated in Figure 71.2. The cardiothoracic ratio is determined as a ratio of the fetal heart compared to the thoracic area. In this example, it is 8.27/35.31 cm2 = 23% and normal. The cardiac axis is the imaginary axis between the line joining the fetal spine with the middle of the fetal frontal chest and the line drawn along the plane of the interventricular septum. It is 30° in this example and normal. This Figure correlates with Movie clip 71.1.

and need to be pursued in a fractionated manner (Figs 71.1 to 71.37, Movie clips 71.1 to 71.26). It is helpful to keep a mental checklist that allows a complete anatomical and functional three-dimensional (3D) picture to form while the study is being conducted or reviewed.

Four-Chamber View This view is part of the obstetric standard for anatomy scan. Some very important and critical cardiac lesions are readily picked up in this view such as hypoplastic left or right heart, mitral or tricuspid atresia, atrioventricular (AV) canal defects balanced or unbalanced, double inlet left ventricle, single ventricle type situations, and large septal defects. While such a diagnosis may be striking at the very onset of the examination, this view alone is inadequate for a complete assessment. In more subtle situations of ventricular or atrioventricular valve discrepancy, each of these structures needs to be measured in the cardiac cycle that reaches its maximal dimension and compared to gestational age-based norms.58–60 This view demonstrates

1532


Fig. 71.2: Situs determination and ventricular morphology. The fetus is in vertex position. With the transducer notch toward the left of the maternal abdomen, this image indicates the heart is within the left chest. Situs can also be cross-checked with the second technique demonstrated in Figure 71.1. The descending aorta (DAo) is seen in cross section to the left of the fetal spine. The left atrium is the left-sided upper chamber, identified by the presence of a right and a left-sided pulmonary vein entering it posteriorly (marked *). The redundant foraminal membrane is seen to separate the right and left atria and is usually bulging into the left atrium secondary to right-to-left shunting at this level across the patent foramen ovale (PFO). The primum component of the interatrial membrane is noted to be intact. The morphologically right ventricle (RV) is noted with a trabeculated apex. The left ventricle (LV) has a more rounded apex with less trabeculations. The tricuspid valve (TV) and mitral valve (MV) are seen on the right and left sides, respectively. This Figure correlates with Movie clip 71.2.

Fig. 71.3: Inferior vena cava (IVC), hepatic veins (Hep V), and ductus venosus (DV). The inferior vena cava is right-sided in this fetus with levocardia. It is joined by the right and left hepatic veins as well as the ductus venosus, which can be identified as a turbulent region on color Doppler along the course of the umbilical vein to the IVC. These venous structures connect to the right atrium (RA). This Figure correlates with Movie clip 71.3.

Fig. 71.4: Two-dimensional (2D) bicaval view. In this transverse view, the fetal head is to the left of the screen and the fetal abdomen is toward the right. The inferior vena cava (IVC) receives the hepatic veins (**) before joining the right atrium (RA). The right superior vena cava (RSVC) is seen entering the RA from the cranial aspect of the fetus. The diaphragm separates the liver and abdominal contents from the lung and the heart in the thorax. The azygous vein (*) is seen joining the RSVC. (Movie clip 71.4).

Fig. 71.5: Color Doppler across interatrial membrane. The interatrial membrane region is marked * and indicates right-to-left shunting from the right atrium (RA) to the left atrium (LA) in this normal fetus. (Movie clip 71.5).


1533

Fig. 71.6: There is laminar color Doppler flow across the tricuspid (TV) and mitral (MV) valves from the right (RA) and left atria (LA) to their respective ventricles (RV, LV). There is no obvious shunting at the interventricular septal level. (Movie clip 71.6).

Fig. 71.7: Pulsed wave Doppler across the tricuspid valve showing “a” wave dominance in this 28-week fetus. (Movie clip 71.7).

Fig. 71.8: Pulsed wave Doppler across the mitral valve showing in this 28-week fetus. (Movie clip 71.8).

Fig. 71.9: Color Doppler of pulmonary veins. The pulmonary venous connections are elicited by applying color Doppler in views demonstrating the back of the left atrium and lowering scales until they can be easily visualized and interrogated with pulse Doppler. This Figure correlates with Movie clip 71.7. (DAo: Descending aorta; LLPV: Left lower pulmonary vein; LUPV: Left upper pulmonary vein; PFO: Patent foramen ovale; RUPV: Right upper pulmonary vein). (Movie clip 71.9).

Fig. 71.10: Pulse Doppler of pulmonary vein. In this image, the right upper pulmonary vein is being interrogated after it was identified on color Doppler. Note that there is some contamination of the signal with the right pulmonary artery signal—seen as the sharp systolic wave below the baseline. This coincidentally demonstrated the “s”wave of the pulmonary venous Doppler, followed by the “d”-wave. (Movie clip 71.10).

1534


Fig. 71.11: Short-axis mitral valve, interventricular septum, moderator band attachment. The left ventricle (LV) is identified by its circular contour, presence of two papillary muscles and mitral valve (MV), and smooth interventricular septum. The right ventricle is the anterior chamber and its outflow is seen wrapping around the left ventricle in a relatively oblong manner. The septal attachment of the moderator band is identified. (Movie clip 71.11).

Fig. 71.12: Short axis of interventricular septum (IVS). Multiple sweeps up and down of the interventricular septum need to be performed to determine the ventricular morphology as well as look for any obvious drop-outs suggestive of ventricular septal defects. This Figure correlates with Movie clip 71.12.

Fig. 71.13: Color Doppler ventricular septum short axis. Color Doppler is applied to images in Figure 71.12. The interventricular septum is intact in this view. This Fig. correlates with Movie clip 71.13.

Fig. 71.14: Two-dimensional (2D) biventricular outflow views show crisscrossing. From the four-chamber—equivalent view of the fetal heart—sweeping anteriorly in the fetal chest brings out the left ventricular outflow tract (marked in cross hatched line) and then the right ventricular outflow tract (marked by continuous line) as they arise from their respective ventricles. The outflow tracts are noted to crisscross and this aspect is important to identify normal outflow anatomy. This Figure correlates with Movie clip 71.14.

atrial as well as ventricular morphology and atrioventricular concordance. A posterior sweep to the coronary sinus and anterior sweep to the pulmonary valve will show critical intervening cardiac structures such as septum primum, inlet, membranous and muscular interventricular septum,

and bilateral AV valve morphology and function. The left atrium is the most posterior structure and at least one rightand one left-sided pulmonary vein can be seen entering it in this view, confirmed on color and spectral Doppler. The coronary sinus can be seen as a small structure parallel


1535

Fig. 71.15: Two-dimensional (2D) right ventricular outflow, pulmonary valve (PV). The right ventricle (RV) is the anterior chamber and its outflow is seen wrapping around the left ventricle in a relatively oblong manner. The PV and main pulmonary artery (MPA) are seen in this image. The aortic valve is seen at the crux of the heart at the same level as the PV and is marked as X in this image. This image correlates with Movie clip 71.15.

Fig. 71.16: Two-dimensional (2D) left ventricular outflow tract. The left ventricle is identified. Sweeping slightly anteriorly in the fetal chest and with some angulation to bring out the left ventricular outflow tract, which is seen to be unobstructed and open in this view. The aortic valve (AoV) and ascending aorta (Ao) are noted. The right pulmonary artery is seen to traverse behind the ascending aorta. The membranous region of the interventricular septum between the aortic valve and the tricuspid valve is additionally seen in this particular image (*). This image correlates with Movie clip 71.16.

Fig. 71.17: Color Doppler laminar flow across pulmonary valve (X). (Movie clip 71.17).

Fig. 71.18: Color Doppler laminar flow across aortic valve ( ) and aortic arch (AoAr). (Movie clip 71.18).

to the posterior left atrioventricular groove, entering into the inferior aspect of the right atrium—obvious dilatation can be seen in conditions where it receives a left-sided superior vena cava (LSVC). An intact septum primum can be critical to the diagnosis of an endocardial cushion defect or atrioventricular canal defect (AVCD). A large drop out in the interatrial membrane is readily obvious

and the bulging of thin foraminal rims into the left atrium indicates the direction of shunting at this level from right atrium to left atrium—this can be confirmed on color Doppler in orthogonal views of the interatrial membrane. The tricuspid valve and the right ventricle are mildly dominant toward latter gestation, although both sides appear relatively symmetric in earlier gestation. Defects

1536


Fig. 71.19: Pulse Doppler across pulmonary valve. (Movie clip 71.19).

Fig. 71.20: Pulse Doppler across proximal transverse aortic arch. (Movie clip 71.20).

Fig. 71.21: Short axis of aortic valve (marked as X). The symmetric and trileaflet anatomy of the normal aortic valve is seen in this image. This view is particularly useful to illustrate the morphology of an abnormal aortic valve as annular hypoplasia, valve thickening, and asymmetry. The tricuspid valve (TV) leading to the right ventricle and right ventricular outflow tract (RVOT) is noted. The patent foramen ovale (PFO) is well profiled in this view. (Movie clip 71.21).

Fig. 71.22: Two-dimensional (2D) short axis both semilunar valves and right pulmonary artery (RPA). The pulmonary valve (P) is more anterior and slightly larger. The main pulmonary artery and its bifurcation into the right and left pulmonary arteries are noted by cranial angulation from this view or by opening these vessels out from the three-vessel view. The right pulmonary artery traverses behind the ascending aorta. (Movie clip 71.22).

in the inlet, membranous, muscular, and apical regions of the interventricular septum may be evident in this view, but all components of the interventricular septum should be assessed in multiple views and specifically in views perpendicular to the plane of the defect so as to minimize drop out artifact due to parallel beam orientation. Deviation ≥ 2 standard deviations or z score ≥ 2 compared to gestation-based norms as well as serial evaluation of ventricular major and minor dimensions are very helpful in determining if one side is larger or smaller by itself or merely appears to be so due to a smaller or larger other

side. This comparison has been found to be very useful in situations of ventricular hypoplasia, unbalanced AV canal defects, severe semilunar valve obstructions, fetal coarctation and heart failure, or high-output situations. Fractional area of shortening may be used to assess systolic function. Color Doppler in this view demonstrates lack of antegrade flow in AV valve atresia, valve incompetence, VSD flow, and outflow directions. Spectral Doppler should be used to ascertain the inflow pattern of the right as well as left side as well as incompetence jets. Tissue Doppler has been used in an attempt to analyze systolic


1537

Fig. 71.23: Two-dimensional (2D) of ductal and aortic arches, isthmus (*). The ductal arch (DuAr) is anterior and describes a gradual curve slightly rightward and posteriorly where it is met at the isthmus (*) by the more posterior and acutely angulated aortic arch (AoAr). (Movie clip 71.23).

Fig. 71.24: Transverse aortic arch, and head and neck vessels. The fetal head is to the left of this screen image. The transverse aorta (TrAo) has been opened out to demonstrate each of the head and neck vessels, the last one being the left subclavian artery (LSCA). This image set is important to demonstrate head and neck vessels as well as indicators or aortic arch anomalies. The aortic isthmus is distal to the LSCA and needs to be clearly visualized to rule out aortic coarctation. (Movie clip 71.24).

Fig. 71.25: Two-dimensional (2D) of three-vessel view and pulmonary artery (PA) bifurcation. The orientation of the fetal chest is marked. The fetal spine (Sp) marks the posterior aspect. The descending aorta (DAo) is seen just to the left and anterior of the spine. The three vessels noted from left to right as well as anterior to posterior are the PA, aorta (Ao), and right-sided superior vena cava (RSVC) in that order of location as well as decreasing size. Identification of the location as well as relative sizes of the great vessels in this view is critical in detecting and confirming presence of obstruction, size discrepancy as well as arch anomalies. The right pulmonary artery (RPA) is seen to arise from the main PA and traverses posterior to the aorta as well as RSVC as it heads to the right lung hilum. (Movie clip 71.25).

Fig. 71.26: Two-dimensional (2D) features of the ductal arch. The ductal arch is the continuation of the pulmonary artery after it arises from the right ventricle (RV) and pulmonary valve (PV), and after this vessel has given rise to the right pulmonary artery (*) and left pulmonary artery (**). The ductal arch is the larger of the two arches and dives posteriorly to join the aortic arch at the aortic isthmus. In this Figure, the isthmus is not well profiled, and that view will need to be developed along with the aortic arch to establish anatomy as well as flow in the isthmic region. This is important to predict fetal aortic coarctation. (Movie clip 71.26).

1538


Fig. 71.27: Two-dimensional (2D) features of the aortic arch. The ascending aorta (AscAo) gives rise to the right innominate (*), left common carotid artery (**), and the left subclavian artery (***) before it joins the ductal arch at the aortic isthmus. (Moive clip 71.27).

Fig. 71.28: Two-dimensional (2D) three-vessel view. In this additional example of a normal three-vessel view, the orientation of the fetal chest is marked. The fetal spine (Sp) marks the posterior aspect. The descending aorta (DAo) is seen just to the left and anterior of the spine. The three vessels noted from left to right as well as anterior to posterior are the pulmonary artery (PA), aorta (Ao), and right-sided superior vena cava (RSVC) in that order of location as well as decreasing size. Identification of the location as well as relative sizes of the great vessels in this view is critical in detecting and confirming presence of obstruction, size discrepancy as well as arch anomalies. The right pulmonary artery (RPA) is seen to arise from the main PA and traverses posterior to the aorta as well as RSVC as it heads to the right lung hilum. (Movie clip 71.28).

Fig. 71.29: Two-dimensional (2D) evaluation of the aortic isthmus. The aortic outflow in the crux of the heart is marked (**) and gives rise to the aortic arch. The head and neck vessels are seen arising from the top of this arch. The isthmus is seen as the region after the left subclavian opposite the insertion of the ductus arteriosus (*).

Fig. 71.30: Pulse Doppler across ductus venosus.


Fig. 71.31: Pulse Doppler across inferior vena cava (IVC).

Fig. 71.32: Pulsed wave Doppler of hepatic vein.

Fig. 71.33: Pulse Doppler across umbilical artery.

Fig. 71.34: Pulse Doppler across umbilical vein.

Fig. 71.35: Umbilical cord vessels. The umbilical vein (*) is relatively thin walled and of larger caliber. There are two umbilical arteries (-) that are thicker walled and of smaller lumen.

1539

and diastolic function of both ventricles,61,62 although this tool has not been fully explored secondary to the numerous unknown factors that can impact it and also lack of robust interobserver variability. From this nodal four-chamber view, a more anterior tilt will bring out the left ventricular outflow. The aortic valve can be well seen and measurements made in this view. Outflow tract as well as aortic valve issues can be seen in this view and further interrogated with color as well as spectral Doppler. The left ventricular cardiac output can be calculated by determining the systolic dimension of the aortic annulus and the velocity time integral of the transaortic pulsed wave Doppler. On further tilting toward the anterior fetal chest, the right ventricular infundibulum is seen to lead to the pulmonary valve. Crisscrossing of the great arteries with the pulmonary artery being the more anterior and leftward is reassuring for normal great artery relationship.

1540


Fig. 71.36: Situs sweep in this 24-year-old Gravida 2 referred due to maternal history of aortic stenosis. This echo was performed at 31 1/7 week gestation. The reader is basically oriented with the use of labels as the “Cordes technique” is used to determine situs. The horizontal bar (/) indicates that the more apically displaced tricuspid valve is located on the right side—this is the normal tricuspid valve leading to the morphological right ventricle. (Movie clip 71.36).

Fig. 71.37: Two-dimensional (2D) ductal and aortic arches. The ductal arch (DuAr) is anterior and describes a gradual curve slightly rightward and posteriorly where it is met at the isthmus ( ) by the more posterior and acutely angulated aortic arch (AoAr). (Movie clip 71.37).

Loss of this relationship will be obvious in other views and allows diagnosis of malposition syndromes. However, semilunar valve function may not be easily separated in this view. Short-axis views are possible in multiple planes perpendicular to the long-axis view. A central reference image is of the right ventricular outflow tract as it wraps around the left ventricle. Ventricular septal defects with outlet or conal extension can be seen in this scan-plane and deviation of the conal septum can be appreciated in this view. Presence of conal deviation, even in the absence of significant outflow obstruction, merits serial follow-up to monitor for in utero progression to a potential ductaldependent situation. Such progression of intracardiac findings has been shown in tetralogy of Fallot (TOF) as well as hypoplastic left heart syndrome (HLHS).63–68 A common underpinning of such in utero progression is a commonly believed concept of antegrade flow being a stimulus for growth of valves and cavities. Slight leftward angulation from this view will bring the pulmonary valve, main pulmonary artery, right and left branch pulmonary arteries as well as ductal arch into view. A more cephalad sweep with some rightward angulation will develop the “three-vessel view” in the superior mediastinum of the fetus. The main pulmonary artery, aorta, and right-sided superior vena cava are lined as in decreasing order of size from the leftward and anterior most location (PA) to

the most rightward and posterior location (RSVC). This view can provide insight into flow discrepancies in the subpulmonic and subaortic ventricle, in the respective semilunar valves, or in the great arteries.69 For example, the three-vessel (3V) view in TOF will demonstrate a smaller and mildly posteriorly (and cranially) displaced pulmonary artery. A smaller aortic dimension is seen with HLHS and its variants. Bilateral SVC is suspected if there is another circular signal to the left of the pulmonary artery and at the same anteroposterior level as the RSVC. Various aortic arch anomalies including coarctation, interruption, double aortic arch, and vascular slings can also be appreciated in this view. If the PA and aorta are opened out in this view, these vessels will be seen to dive posteriorly as they transit into the ductal and aortic arches, respectively. Once again, this view is a visual demonstration of expected size proportion. The ductal and aortic arches meet in the aortic isthmus and measurements as well as color and Doppler here can raise concern for coarctation if the isthmus is narrowed or if there is flow turbulence or increased velocity across this region. Also, if there is an abnormal flow pattern in either arch, it will be readily noted on color Doppler, although the size discrepancy in severe stenosis situations can make it difficult to open these two arches in single view consistently. Focusing on the aortic arch, the sidedness can be determined based on the direction of a left-sided arch diving from a rightward


anterior location to its leftward posterior location to the left of the trachea. In most of these cephalad planes, the thymus can be seen in the anterior mediastinum—its hypoplasia along with a conotruncal lesion may indicate 22q11 deletion spectrum. Ventricular long-axis view is obtained by aligning the transducer along the left ventricular outflow. Ventricular septal defects, aortic override (pathognomonic of TOF), aortomitral continuity, goose-neck deformity (pathognomonic of AVCD), mitral and aortic valve sizes as well as ventricular morphology can be well seen in this view. Fetal noncompaction of the myocardium can be a controversial diagnosis in early gestation but may be remarkable enough to appear convincing in later gestation. Left ventricular basal wall function as well as overall systolic function can be assessed. Unusual morphologies such as left ventricular diverticulum and fetal rhabdomyomas may be well delineated in this view. Spectral Doppler in this or the four-chamber view with the pulsed wave Doppler gates across the mitral as well as aortic valves can be optimized to show the “inflow–outflow Doppler” to calculate. This is an accepted method to determine the mechanical PR interval in maternal systemic lupus erythematosus or Sjogren’s syndrome, where there is risk for fetal heart block, to calculate isovolumic relaxation time and the fetal Tei index.61 Caval long-axis view lines up the inferior vena cava (IVC) as well as SVC entering the right atrium. From this view, the right pulmonary artery passing behind the RSVC and sometimes a prominent azygous vein entering the RSVC can be appreciated. A dilated RSVC may be an indicator of an arteriovenous malformation in the head and neck region, commonly in the cerebral territory. Such a finding may also raise suspicion for anomalous pulmonary venous drainage and should be followed by attempts to delineate at least three of the pulmonary veins. At this level, the IVC as well as the hepatic vein should be interrogated by spectral Doppler and as the IVC is traced further to ensure that it is uninterrupted. An interrupted IVC is a marker for heterotaxy syndrome, usually of the left atrial isomerism type. From this view, color Doppler over the liver region can identify the ductus venosus as a narrowing in the course of the umbilical vein to the IVC. Once identified on color Doppler, spectral Doppler is used to show the flow pattern in this structure. Ductal and aortic arch views are best developed perpendicular to the three-vessel view. The aortic arch is higher and describes a wider arch, likened to the “candy cane”. It is identified by the origin of the head and neck

1541

vessels from the top of the curve. The ductal arch describes a tighter curve and is described as a “hockey stick” as it joins the aortic arch. Sweeping back and forth amidst these two arches allows separation of these arches. A proportionate size, as well as laminar antegrade flow on color Doppler are reassuring for preserved fetal physiology and right-to-left shunting at the ductal level. Resistance and pulsatility indices can be calculated and are valuable indicators to differentiate increased flow across the ductus (increased right ventricular output) from ductal constriction (due to maternal nonsteroidal ingestion).70,71 A size discrepancy needs further assessment. In ductaldependent systemic circulations, there is antegrade flow in the ductal arch, possible abnormal flow in the isthmus, and potentially retrograde flow in the transverse aortic arch. In ductal-dependent pulmonary circulation, the ductus is abnormally angulated and arises more “vertically” from the undersurface of the aortic arch, and has retrograde flow indicating that even in the fetal stage, pulmonary circulation is dependent on a retrograde ductus. Identifying both these entities is critical as it has ramifications on fetal counseling, preparing a more detailed birth plan including initiation of prostaglandins soon after birth.

Fetal Cardiac Function Left ventricular shortening fraction can be calculated using either two-dimensional images or M-mode interrogation at the level of the papillary muscles on the left side and at midlevel in the right side. Normal left and right ventricular shortening fraction is 34% ± 3% after 17 weeks gestation.72 Poor reproducibility of modified biplane Simpson technique-based ventricular ejection fractions contrasts with the better reproducibility and variability in three- and four-dimensional (4D) measurements of ventricular volumes and mass.73–75 A cardiovascular profile score has been widely used to reflect fetal cardiac status. This composite score gives 2 points each for presence or absence of hydrops, Doppler pattern in the umbilical vein and ductus venosus, heart size based on cardiothoracic ratio, cardiac function based on inflow pattern, AV valve incompetence and shortening fraction, and finally Doppler pattern in the umbilical artery.76 Across both mitral and tricuspid valve, the E-wave is smaller and the A-wave is dominant and the E/A ratio is usually <1, presumably due to the reduced compliance of the ventricular myocardium toward the end of the first trimester. As pregnancy progresses, improved ventricular compliance is manifested as increased E-wave and increasing E/A ratio across both valves.77–81 Similar to

1542


the postnatal and adult experience, a fetal myocardial performance index can be derived based on inflow and outflow Dopplers. A higher myocardial performance index indicates a greater amount of dysfunction, although it may not separate out systolic from diastolic dysfunction. This Tei index can be compared with recently published norms and is shown to be relatively stable across gestation (mean MPI = 0.36, range 0.28–0.44).61,82–84 The fetal isovolumic relaxation time is the interval between closure of the semilunar valves and opening of atrioventricular valves with a mean value of 34 ms (range is 26–41 ms).82,85 The greatest utility of these parameters may be in the longitudinal follow-up in a particular fetus with cardiac or extracardiac pathology affecting this parameter.

Core and Cord Dopplers This term describes the spectral Doppler pattern in the umbilical artery, umbilical vein, ductus venosus, IVC, hepatic vein, and middle cerebral artery. Venous structures closest to the heart are the first to manifest changes secondary to increased filling pressures. Both the hepatic vein and the IVC show a triphasic pattern similar to the “s,” “d,” and “a” wave pattern seen in mature venous systems. Prominent “a”-wave reversal indicates elevated filling pressures, low velocity “s”-waves indicate presence of important tricuspid incompetence. It is recommended to acquire umbilical artery (UA) and umbilical vein (UV) signals in a free loop of umbilical cord midway between the placenta and the fetus. The umbilical venous flow carries blood from the placenta to the fetus and is a low velocity, continuous, nonphasic flow. Appearance of “notching” with decrease in centripetal flow during the cardiac cycle is abnormal. The umbilical artery carries fetal deoxygenated blood from the fetus to the placenta. The low placental vascular resistance allows systolic as well as diastolic flow, which can be quantified using the pulsatility index. This index is elevated in intrauterine growth retardation and in the donor of TTTS. Middle cerebral artery is interrogated midway after its origin from the circle of Willis and the lateral cranium. Unlike the UA, there is minimal diastolic flow in this vessel because of elevated cerebrovascular resistance—in situations where the fetus is adapting to a poor circulatory situation by decreasing its vascular resistance; there is more diastolic flow in this artery.86 Accompanying case studies illustrate all the above principles, multiple imaging views, and diagnostic information in a variety of anatomical situations. (See Figs

71.38 to 71.93 and the corresponding movie clips, and also Movie clip 71.94).

Fetal Cardiac Rhythm Assessment Rhythm assessment is integral to a screening echocardiogram. Although the primitive heart tube demonstrates organized contractions by 12 days postconception, the conduction system is developed by 16 weeks of gestation, later than the fetal cardiac structures at 12 weeks.87 Fetal heart rate varies through gestation, ranges about 110 to 180 beats/minute (bpm) in the first trimester, maximum rate achieved at 9 weeks gestation, and averaging about 135 bpm (110–150 bpm) by later trimesters.88,89 Pulse Doppler or M-mode techniques can be used to detect the rate of cardiac events. To determine the atrioventricular synchrony, simultaneous inflow–outflow Dopplers such as SVC and aorta, mitral valve and aorta, pulmonary artery and pulmonary vein, and M mode through atrial as well as ventricular structures can to be analyzed.90,91 Unfortunately, all these techniques require persistence and skill due to challenges from fetal position, fetal movement, and image resolution. Fetal arrhythmias and premature beats can be quite striking at the time of an obstetric scan, but the vast majority of referrals for reasons of fetal arrhythmia reveal premature atrial beats or no rhythm issues.92 Premature atrial contractions are 10 times more common than premature ventricular contractions; both have a combined occurrence of about 1.7% in third trimester studies.93 The relationship between atrial and ventricular contractions and their respective rates usually allows identification of supraventricular tachycardia (SVT), atrial flutter, junctional ectopic tachycardia, and ventricular tachycardia. Fetal SVT with 1:1 atrial (A): ventricular (V) contraction is the commonest at 66–90% of all fetal tachyarrhythmia and is the cause of nonimmune hydrops in many. These can be further divided into short and long V-A types.91 The ventricular rate is typically 250 bpm, and there is 1:1 A:V relationship. The latter feature separates fetal SVT from the second commonest fetal tachyarrhythmia, which is atrial flutter. In atrial flutter, atrial rates may range from 350– 500 bpm, eventual ventricular rate depending on AV conduction. Rapid ventricular rates without V-A synchrony suggest ventricular and junctional ectopic tachycardia. Besides meticulous rhythm studies in affected fetuses, the structure of the fetal heart must also be assessed in detail since structural defects can coexist in an important number. Tachycardias are described as “sustained” if


1543

Case VSD 1. Fig. 71.38: Ventricular septal defect in four-chamber view. The right and left atria (RA, LA) and ventricles (RV, LV) as well as respective atrioventricular valves are labeled (TV, MV). A drop-out (*) is noted at the crest of the interventricular septum in this image and is suspicious for a ventricular septal defect. (Movie clip 71.38).

Case VSD 1. Fig. 71.39: Two-dimensional (2D) ventricular long axis with ventricular septal dropout in high muscular region. (Movie clip 71.39).

Case VSD 1. Fig. 71.40: Color Doppler ventricular long axis with ventricular septal dropout in high muscular region confirms the presence of a septal defect in this region. (Movie clip 71.40).

Case VSD 1. Fig. 71.41: Three-vessel view (3VV) with Bilateral superior vena cava (BLSVC). The ductal arch (DuAr) and aortic arch (AoAr) are appropriate in their relative orientation as well as size. However, there are two good-sized bilateral superior vena cava [right-sided superior vena cava (RSVC) and left-sided superior vena cava (LSVC)] noted in this view. (Movie clip 71.41).

Case VSD 1. Fig. 71.42: Postnatal confirmation of high muscular ventricular septal defect (VSD). (Movie clip 71.42).

1544


Case VSD2. Fig. 71.43: Midmuscular ventricular septal defect (VSD; *). This defect is suspected in the muscular septum just proximal to the moderator band in the right ventricle. Note that in this instance, the angle of insonation is parallel to the drop-out and suspected defect.

Case VSD 2. Fig. 71.44: Orthogonal view of midmuscular ventricular septal defect (VSD). This is the same patient and imaging session as in Figure 71.1. In this image, the previously suspected ventricular septal defect is confirmed on color Doppler as well as a nearly perpendicular angle of insonation.

Case AVCD. Fig. 71.45: Four-chamber identification of atrioventricular canal components. A fetal echocardiogram was performed for this 38-year-old G6P4 with Marfan syndrome and a fetus at 28 5/7 weeks gestation with trisomy 21 confirmed on amniocentesis. The left ventricle is left-sided and on the left of the screen. The right ventricle is identified with its apical trabeculations. A large atrial septal defect including the septum primum (**) is seen along with a large ventricular septal defect (*). The common atrioventricular valve is seen to sit astride this large defect in the crux of the heart.

Case AVCD. Fig. 71.46: Atrial morphology and atrioventricular canal defect (AVCD). The right atrial appendage is broad-based triangular and with dense pectinate muscles—this identifies the right atrium and is seen in this image as “a.” The left atrial appendage is smaller, thin, and finger-like and has fewer pectinate muscles—seen in this image on the left side and labeled “l.” The pulmonary veins are seen to enter into the back of the left atrium. The large common atrium communicates via a common atrioventricular valve with the ventricles distally. The ventricular septal defect (VSD) is noted (*).

they occur for >50% of the study period, otherwise they are considered “nonsustained.” Functional parameters including ventricular dimensions, cardiothoracic ratios, presence and severity of AV valve incompetence, output, cord and core Dopplers, and presence of hydrops need to be serially collected and interpreted—these are invaluable

to decide on when to start maternal medications and also to follow up the effect of the rhythm disturbance as well as medication. Most premature beats and nonsustained tachycardias can be monitored without intervention while fetal well-being is monitored. Oral maternal medications in th e form of digoxin, flecainide, sotalol, terbutaline, and


Case AVCD. Fig. 71.47: Short-axis view of common atrioventricular (AV) valve demonstrates the single valve, and its anterior and posterior leaflets as well as right and left components. The anterior leaflet has connections to the crest of the interventricular septum in this example, indicating that it is likely to be Rastelli type 1. The pulmonary valve (PV) is noted anteriorly and is of a good size.

Case AVCD. Fig. 71.49: Three-vessel view—discrepancy and left-sided superior vena cava (LSVC). The reader is encouraged to orient the structures and note that the three-vessel view is abnormal. Firstly, the aorta (Ao) is much smaller than the pulmonary artery (P). Secondly, there is a left-sided structure in the same plane as the right-sided superior vena cava and of equivalent size on the left of the pulmonary artery—this indicates the presence of the left SVC as also demonstrated in Figure 71.4. The relative disproportion is concerning for left ventricular outflow tract or aortic abnormalities or for smaller aortic arch. The ascending as well as transverse arch measured small, and the last head and neck vessel seemed to be directed toward the fetal neck with no continuity with the remaining ductal arch. This anatomy was suspicious for interrupted aortic arch.

1545

Case AVCD. Fig. 71.48: Left-sided superior vena cava (LSVC) to CS, smaller aorta. The LSVC is noted to drain into the right atrium and the roof of the coronary sinus appears to be intact on this two-dimensional (2D) image. This was confirmed on color Doppler. The aorta (X) is seen in the crux of this view and appears to be smaller than the anterior pulmonary valve.

amiodarone are important decisions that allow rate as well as rhythm control but have important implications for the mother as well as fetus.94–98 Fetal bradycardia is diagnosed when the ventricular rates are < 100 to 110 bpm. These low heart rates may occur transiently and with no adverse outcome secondary to vagal stimulus. More persistent bradycardia is an indicator of a compromised fetus. CCHB with overall ventricular rates of 30 to 120 bpm can arise due to maternal autoimmune illnesses such as systemic lupus erythematosus (SLE) and Sjögren’s syndrome and also from fetal structural heart disease such as heterotaxy syndromes (left atrial isomerism), l-looped ventricles, rarely idiopathic. CCHB due to maternal autoantibodies anti-Ro (anti-SSA), and anti-La (anti-SSB) is presumably due to affinity of these transplacentally transmitted antibodies to the fetal conduction system and rarely to the myocardium. First and second degree heart block are amenable to diagnosis and treatment with maternal steroids; third degree heart block is generally thought to be irreversible. Stabilization and even reversal of first and second degree AV block with maternal fluorinated steroids has resulted in this being the treatment of choice. Others have reported additional improvement in outcome with maternal use of intravenous immunoglobulins, especially if the myocardium is also affected.99–103 Fetal bradycardia can also be seen in long QT syndrome.104

1546


Case Dextrocardia. Fig. 71.50: In this situs sweep, the cardiac apex is directed toward the right of the fetal chest. This fetus was referred due to abnormal obstetric scan and this study was performed at 26 3/7 weeks gestation. The fetus is in breech position.

Case Dextrocardia. Fig. 71.51: Situs sweep with dextrocardia and right-sided stomach. This indicates that the heart as well as the stomach are located in the right side of the body, that is, cardiac as well as abdominal situs inversus. (Movie clip 71.51).

Case Dextrocardia. Fig. 71.52: Asymmetric four-chamber view, atrioventricular canal defect (AVCD). A common atrioventricular valve is suspected accompanied by an atrial and ventricular septal defect (*). Left-sided atrium appears to have the right atrial appendage (RAAp) and hence the right atrium. The left atrium is right-sided and receives the pulmonary veins. The right-sided left ventricle appears to be smaller than the other ventricle. (Movie clip 71.52).

Case Dextrocardia. Fig. 71.53: Pulmonary veins to right-sided left atrium. The right and left pulmonary veins are seen to join the back of the right-sided left atrium in this color Doppler image. (Movie clip 71.53).

Safety of Fetal Ultrasound

ultrasound energy can be theoretically secondary to its thermal effect relating to increase in temperature in the region of insonation, or mechanical, relating primarily to cavitation. Most ultrasound systems allow for display of potential increase in temperature in the field by displaying the thermal index for either soft-tissue (TIS), or bone (TIB). The TI represents an estimate of the temperature rise in the field and is approximately proportional to

Prolonged and/or repeated fetal ultrasound is sometimes required in fetal diagnosis. Despite theoretical concerns, no confirmed harmful effects have been detected over the years. The use of each imaging modality is associated with ultrasound energy expenditure, most with the use of color Doppler in a small region of interest. Bioeffects of


1547

Case Dextrocardia. Fig. 71.54: Double outlet right ventricle. In this image, the left-sided right ventricle gives rise to both the great arteries. There is some deviation of the conal septum, so that this protrudes below the pulmonary valve. The pulmonary valve appears to be smaller than the aortic valve (identified as the nondividing vessel). The pulmonary artery (PA) is identified as the vessel that bifurcates distally. The aorta is anterior and larger than the pulmonary artery. This great artery relationship should be confirmed in other views. (Movie clip 71.54).

Case Dextrocardia. Fig. 71.55: Smaller pulmonary artery and bifurcation. The right pulmonary artery (RPA) is red on color Doppler as it moves toward the transducer; the left pulmonary artery (LPA) is blue as it moves away. The main pulmonary artery (MPA) is of smaller caliber than the aorta (Ao) that is directed leftward from its anterior position. (Movie clip 71.55).

Case Dextrocardia. Fig. 71.56: En face view of unbalanced CA valve. The left-sided right ventricle (RV) is more dominant. The smaller right-sided left ventricle (LV) is seen posterior and right of the RV. The common atrioventricular valve is seen on short axis in this view. (Movie clip 71.56).

Case Dextrocardia. Fig. 71.57: Abnormal three-vessel view with aorta anterior and leftward. The aorta is most anterior (**); a smaller pulmonary artery is seen to its right and more posteriorly. Bilateral superior vena cava (SVC) are once again suspected in the same plane (*).

the temperature increase in degree Celsius. The risk of mechanically induced ultrasound damage is displayed by the mechanical index (MI), which is defined as the ratio of maximal peak rarefactional pressure to the square root of the ultrasound frequency. The risk of mechanical injury rises with increasing MI.105–107 As newer modalities such

as Doppler applications assessing tissue motion and realtime 3D imaging continue to develop, bioeffects on the fetus will need to continue to be monitored. As there are no strictly defined limits established, use of ultrasound energy in fetal echocardiography is best expressed by the “ALARA” principle—as low as reasonably achievable.108

1548


Case TA. Fig. 71.58: Four-chamber asymmetry. This four-chamber equivalent view demonstrates asymmetry in ventricular chamber size, the right-sided right ventricle (RV) is smaller, and its apex does not reach up to the cardiac apex. The tricuspid valve above it seems to have plate-like atresia between the right atrium (RA) and RV. A large ventricular septal defect (*) is seen separating the smaller right ventricle from the larger and apex-forming left ventricle (LV). The mitral valve (MV) is seen in its open diastolic position. The interatrial foraminal membrane is seen bulging into the left atrium (LA), suggesting that there is right-to-left flow at this level. (Movie clip 71.58).

Case TA. Fig. 71.59: d-malposition of the aorta. The aorta (Ao) is identified due to its relationship with head and neck vessels. This vessel arises from the anterior and rightward bulboventricular chamber (BVC). Blood enters the BVC through a currently unrestrictive ventricular septal defect (VSD) from the left ventricle (LV). There is no aortomitral continuity and the aorta is of good size. (Movie clip 71.59).

Case TA. Fig. 71.60: d-malposition of the great arteries. The pulmonary valve (PV) leads to a good-sized pulmonary artery that is seen to bifurcate distally. This great vessel is seen to arise from the left ventricle (LV). The ventricular septal defect (VSD; *) connecting this left ventricle to the bulboventricular chamber is not well profiled in this view. (Movie clip 71.60).

Case TA. Fig. 71.61: Origin of malposed great arteries, subpulmonic ventricular septal defect (VSD). The aorta (Ao) is anterior, smaller, and arises from the anterior diminutive right ventricle (RV). The pulmonary artery (P) arises posteriorly from the larger and dominant left ventricle (LV). This indicates ventriculoarterial discordance. A subpulmonic VSD (*) and its relationship to the great arteries is seen clearly. Note that the subpulmonic conus is minimally thickened and deviated into the subpulmonic region. (Movie clip 71.61).


1549

Case TA. Fig. 71.62: Abnormal 3VV in DTGA. The fetal spine (Sp) and anterior aspects are marked. The aorta is rightward and anterior to the pulmonary artery (d-malposed). The right pulmonary artery (RPA) origin from the pulmonary artery (PA) is seen before this vessel continues as the ductal arch (DuAr) to the descending aorta (DAo). (Movie clip 71.62).

Case TA. Fig. 71.63: DTGA, anterior aorta bulboventricular chamber. The reader is encouraged to use the previous images to determine the anatomy in this labeled image. (Movie clip 71.63).

Case HLHS. Fig. 71.64: Asymmetry of the ventricles. A significant fetal structural heart defect is suspected in the early part of this scan due to the obvious asymmetry of the ventricles. The right atrium (RA) and right ventricle (RV) are identified to be of adequate size. The left ventricle (LV) cannot be easily opened out and the atrioventricular valve above it appears plate-like and does not open well. A hypoplastic left heart variant is suspected in this image. (Movie clip 71.64).

Case HLHS. Fig. 71.65: Bicaval view showing foraminal flap. The superior (SVC) and inferior (IVC) vena cavae are seen to enter the right atrium in this bicaval view. The foraminal membrane is seen with the crest of the flap directed toward the right atrium (*), indicating left-to-right flow at this level. Normal atrial level shunting in the fetus is always from the right to the left and presence of an opposite direction of flow indicated impaired left atrial drainage from anatomical or functional causes. (Movie clip 71.65).

Three-Dimensional Imaging

two planes, a 3D data point is called a voxel. This comprises information in all three dimensions. An immense advantage of 3D fetal scanning is that postprocessing can allow navigation within this data set to yield virtual and customizable scan planes that can better depict

3D and 4D (3D + fourth dimension of time) fetal echocardiography requires acquisition of a volume of imaging data. Just as two-dimensional data is defined as a pixel in

1550


Case HLHS. Fig. 71.66: Color Doppler showing left-to-right (LA to RA) shunting at the atrial level (*). This image correlates with Movie clip 71.66.

Case HLHS. Fig. 71.67: Asymmetric three-vessel view. The pulmonary artery is dominant and anterior. A smaller aorta is seen to its right, followed by a right-sided superior vena cava. The pulmonary artery goes on to bifurcate and the right pulmonary artery (RPA) continues behind the aorta. The transverse aorta is suspected to be the diminutive vessel that is headed from the ascending aorta (Ao) toward the leftward aspect of the fetus. (Movie clip 71.67).

Case HLHS. Fig. 71.68: Color Doppler of both arches. Further cranial sweep from the location in Figure 71.4 reveals the aortic and ductal arches. On applying color Doppler, there is antegrade flow through the ductal arch. The point (*) is the isthmus and there is retrograde filling of the aortic arch from this region (red flow toward the transducer). Both arches should be antegrade and symmetric. Presence of asymmetry is a subtle clue to possible hypoplasia, but retrograde flow indicates severe obstruction of one of these arches and is a ductal-dependent pulmonary or systemic circulation at birth. (Movie cilip 71.68).

Case HLHS. Fig. 71.69: Color Doppler showing retrograde transverse aortic arch flow. This image is derived by rotation of the transducer from the position that demonstrated Figure 71.5. Here the aortic arch is identified by the head and neck vessels, and the transverse aorta (AoAr) is seen to fill retrograde from the isthmus and the antegrade ductal arch (DuAr). (Movie clip 71.69).

anatomy as well as relationships between intracardiac and extracardiac structures. When acquired over time and multiple events in one or more cardiac cycles (STIC = spatiotemporal image correlation and other 4D imaging

terminology) it is considered 4D ultrasound. This modality acquires a series of B-mode images and stacks them up to result in a data volume across a cardiac cycle. Such a volume may potentially contain all the imaging


1551

Case HLHS. Fig. 71.70: Spectral Doppler of retrograde aortic arch flow shows that the flow is coming anteriorly and toward the aortic root rather than the normal flow posteriorly and away from the aortic root.

Case HLHS. Fig. 71.71: Retrograde arch flow on power color Doppler. Power color Doppler can be used to bring out color flow phenomenon to advantage. (Movie clip 71.71).

Case HLHS 2. Fig. 71.72: Four-chamber view—smaller left ventricle (LV) and mitral atresia. In this case, a large and hypertrabeculated right ventricle (RV) contrasts with the smaller, non-apexforming LV. The smaller left atrium (LA) is separated from the larger right atrium (RA) by a slightly thickened interatrial septum with a central defect; its edges are bowing into the right atrium. (Movie clip 71.72).

Case HLHS 2. Fig. 71.73: Four-chamber view with no color flow across mitral valve. In this image, while there is antegrade flow across the tricuspid valve into the right ventricle, there is no flow across the mitral valve into the left ventricle in the presence of plate-like mitral atresia. (Movie clip 71.73).

information that is required for fetal cardiac screening.109,110 Volume reconstruction and rendering are postprocessing applications that allow manipulation of the data set to extract relevant information and display. For example, volume rendering of a data set with a fetal ventricular septal defect will demonstrate the location, rims, and extent of the defect. Color flow Doppler has been used as a way of mapping flow in the fetal heart and a combination of 3D and 4D

technologies with color Doppler may be a promising tool for multiplanar display of flow phenomenon.111,112 With the recent availability of live 3D scanning, this technology has been utilized in assessing the fetal heart.113 B-Flow is a non–Doppler-based imaging technology by digital encoding of emitted ultrasound beams into two sub-beams. One of these beams is a high frame rate B-mode display of color flow that is enhanced to increase

1552


Case HLHS 2. Fig. 71.74: Color flow across large apical ventricular septal defect (VSD). This is the only source of blood flow into the left ventricle from the right ventricle. (Movie clip 71.74).

Case HLHS 2. Fig. 71.75: Color Doppler, mitral atresia, and left-to-right flow at patent foramen ovale (PFO). (Movie clip 71.75).

Case HLHS 2. Fig. 71.76: Color contrast in pulmonary veins and patent foramen ovale (PFO). This image illustrates the complexity as well as variable directionality of multiple flows in a small region of interest. Careful attention will allow interpretation and the information thus gathered should appear to be internally consistent and unifying toward the anatomy and physiology. (Movie clip 71.76).

Case HLHS 2. Fig. 71.77: Asymmetric 3VV in mitral atresia—clue for arch hypoplasia. The large ductal arch is a stark contrast to the much smaller and tortuous aortic arch. (Movie clip 71.77).

signal return from normal flow phenomenon. As a result, the lumen dimensions as well as overall cardiac flow phenomenon can be easily visualized. Some investigators have found it to be useful to measure vessel dimensions, others have found it to be highly sensitive to vessel anomalies such as transposition of the great arteries.114–116 Power Doppler and high definition power Doppler are used in conjunction with 3D static imaging or STIC imaging, respectively. They operate at lower velocities and enhance visualization of flow phenomenon with color.117

They have been found to be particularly useful in first and early second trimester scans.118 Fetal cardiac interventions are intended to “normalize” the physiological disturbance that has come about in the developing fetus because of a structural problem. This stems from the observation that improved flow across valves and structures improves their size and function as also the observation that these techniques are both feasible and bear good results. Theoretically at least, it is possible to “improve” the anatomy of the developing heart


1553

Case HLHS 2. Fig. 71.78: Aortic arch deceptively normal in long axis. On this static image, it almost appears as though the aortic arch is being demonstrated and appears to be of good size. In fact, the left subclavian artery is arising from the top of the ductal arch where it meets the diminutive aortic arch. The aortic arch is antegrade due to the flow coming into it from the apical ventricular septal defect (VSD). However, often, a diminutive aortic arch is difficult to trace out along its entire distance and multiple views and clues need to be used. (Movie clip 71.78).

Case HLHS 2. Fig. 71.79: Pulmonary venous Doppler showing consistent but low velocity “a”-wave reversal. This feature will need to be serially followed in this fetus as pregnancy advances, since the natural history of such restrictive atrial septums is to further decrease with time. Presence of atrial level restriction to leftto-right flow adds significant morbidity as well as mortality and may be an indication for fetal intervention or emergent postnatal intervention.

Case PA. Fig. 71.80: Asymmetric four chamber showing tricuspid and right heart hypoplasia. The tricuspid annulus is small and appears to be dysplastic. The right ventricle is smaller and non– apex-forming. (Movie clip 71.80).

Case PA. Fig. 71.81: Longitudinal view showing aortic outflow and ventricular septal defect (VSD; *). The left atrium (LA) and left ventricle (LV) are noted here, with presence of aortomitral continuity. The aortic outflow (Ao) is astride a ventricular septal defect (*). (Movie clip 71.81).

or even temporize it enough to allow for survival, and diminish postnatal mortality and morbidity. Thus, balloon dilatation of the aortic valve in critical aortic stenosis and HLHS, pulmonary valve balloon dilatation in critical pulmonary stenosis or pulmonary atresia with an intact interventricular septum, balloon dilatation of the interatrial septum in cases with HLHS with restrictive interatrial

septum or in d-transposition of the great arteries, and intact interventricular septum all bear potential interest. The greatest constraint facing this field is the substantial ethical issues as well as logistics around it. Encouraging results have been noted in the hands of experienced centers performing interventions at the extreme end of the spectrum of congenital heart disease.119–123

1554


Case PA. Fig. 71.82: Retrograde ductal arch (DuAr) in fetus with pulmonary atresia. (Moive clip 71.82).

Case PR. Fig. 71.83: Four chamber with biventricular apical hypertrophy (*), hyperechogenic ventricular walls (~), and right ventricular chamber dilatation. Accompanying biventricular systolic dysfunction is better seen in the accompanying movie (Movie clip 71.83).

Case PR. Fig. 71.84: Dysplastic pulmonary valve. The pulmonary annulus itself is of a normal size (--), seen here distal to a normal appearing right ventricular outflow tract (RVOT). However, the pulmonary valve leaflets are not discernible—rolled up and thickened leaflet tissue is seen in this location. The main pulmonary artery (MPA) is dilated. (Moive clip 71.84).

Case PR. Fig. 71.85: Color Doppler right ventricular outflow showing free pulmonary incompetence and ductal reversal. A wide regurgitant jet is seen to enter the right ventricle (RV) from across the plane of the previously noted pulmonary annulus. In fact, this reversal is seen to extend into and include the main pulmonary artery (MPA) and the ductal arch (DuAr). (Movie clip 71.85).


1555

Case PR. Fig. 71.86: 3VV dilated pulmonary valve and branch pulmonary artery (PA). (Movie clip 71.86).

Case PR. Fig. 71.87: Color Doppler both arches flow reversal in ductal arch.

Case PR. Fig. 71.88: Pulse Doppler in ductal arch showing diastolic reversal or to–fro flow.

Case PR. Fig. 71.89: Pulse Doppler across ductus venosus showing return to baseline.

Case PR. Fig. 71.90: Pulse Doppler of umbilical artery showing loss of antegrade diastolic flow.

Case PR. Fig. 71.91: Pulse Doppler of umbilical vein with no obvious or significant venous notching.

1556


Case PR follow-up. Fig. 71.92: Two-dimensional (2D) dilated right ventricular outflow tract (RVOT), main pulmonary artery (MPA), and minimal pulmonary valve tissue. There has been marked enlargement of the pulmonary annulus (----) even accounting for the advancing gestation. (Movie clip 71.92).

CASE STUDIES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Case Case Case Case Case Case Case Case Case Case

VSD 1 (ventricular septal defect) VSD 2 (ventricular septal defect) AVCD (atrioventricular canal defect) Dextrocardia TA (tricuspid atresia) HLHS 1 (hypoplastic left heart syndrome) HLHS 2 (hypoplastic left heart syndrome) PA (pulmonay atresia) IEF PR (pulmonary regurgitation).

REFERENCES 1. Hoffman JI, Christianson R. Congenital heart disease in a cohort of 19,502 births with long-term follow-up. Am J Cardiol. 1978;42(4):641–7. 2. Rubin JD, Ferencz C, McCarter RJ, et al. Congenital cardiovascular malformations in the Baltimore-Washington area. Md Med J. 1985;34(11):1079–83. 3. Simpson LL. Structural cardiac anomalies. Clin Perinatol. 2000;27(4):839–63. 4. Oggè G, Gaglioti P, Maccanti S, et al. Prenatal screening for congenital heart disease with four-chamber and outflowtract views: a multicenter study. Ultrasound Obstet Gynecol. 2006;28(6):779–84. 5. Copel JA, Pilu G, Green J, et al. Fetal echocardiographic screening for congenital heart disease: the importance of the four-chamber view. Am J Obstet Gynecol. 1987;157(3): 648–55. 6. American Institute of Ultrasound in Medicine. AIUM Practice Guideline for the performance of an antepartum obstetric ultrasound examination. J Ultrasound Med. 2003; 22:1116–25.

Case PR follow-up. Fig. 71.93: Color Doppler with moderate tricuspid regurgitation (TR). The right ventricle (RV) is dilated and dysfunctional; the right atrium is dilated. (Movie clip 71. 93).

7. American College of Radiology. ACR practice guideline for the performance of antepartum obstetrical ultrasound— Revised 2003 (Res. 19). Amended 2006 (Res. 35). ACR Practice Guidelines and Technical Standards, 2006 ed. Am Coll Radiol. 2006;895–901. 8. ACOG Committee on Practice Bulletins. ACOG Practice Bulletin No. 58. Ultrasonography in pregnancy. Obstet Gynecol. 2004;104:1449–58. 9. Rychik J, Ayres N, Cuneo B, et al. American Society of Echocardiography guidelines and standards for performance of the fetal echocardiogram. J Am Soc Echocardiogr. 2004;17(7):803–10. 10. Small M, Copel JA. Indications for fetal echocardiography. Pediatr Cardiol. 2004;25(3):210–22. 11. Buskens E, Stewart PA, Hess J, et al. Efficacy of fetal echocardiography and yield by risk category. Obstet Gynecol. 1996;87(3):423–8. 12. Kumar RK, Newburger JW, Gauvreau K, et al. Comparison of outcome when hypoplastic left heart syndrome and transposition of the great arteries are diagnosed prenatally versus when diagnosis of these two conditions is made only postnatally. Am J Cardiol. 1999;83(12):1649–53. 13. Tworetzky W, McElhinney DB, Reddy VM, et al. Improved surgical outcome after fetal diagnosis of hypoplastic left heart syndrome. Circulation. 2001;103(9):1269–73. 14. Bonnet D, Coltri A, Butera G, et al. Prenatal diagnosis of transposition of great vessels reduces neonatal morbidity and mortality. Arch Mal Coeur Vaiss. 1999;92(5):637–40. 15. Allan LD, Cook A, Sullivan I, et al. Hypoplastic left heart syndrome: effects of fetal echocardiography on birth prevalence. Lancet. 1991;337(8747):959–61. 16. Kovalchin JP, Silverman NH. The impact of fetal echocardiography. Pediatr Cardiol. 2004;25:299–306.


17. Quartermain MD, Glatz AC, Goldberg DJ, et al. Pulmonary outflow tract obstruction in fetuses with complex congenital heart disease: predicting the need for neonatal intervention. Ultrasound Obstet Gynecol. 2013;41(1): 47–53. 18. Donofrio MT, Levy RJ, Schuette JJ, et al. Specialized delivery room planning for fetuses with critical congenital heart disease. Am J Cardiol. 2013;111(5):737–47. 19. Rogers L, Li J, Liu L, et al. Advances in fetal echocardiography: early imaging, three/four dimensional imaging, and role of fetal echocardiography in guiding early postnatal management of congenital heart disease. Echocardiography. 2013;30(4):428–38. 20. Garne E, Loane M, Dolk H, et al. Prenatal diagnosis of severe structural congenital malformations in Europe. Ultrasound Obstet Gynecol. 2005;25(1):6–11. 21. Wong SF, Chan FY, Cincotta RB, et al. Factors influencing the prenatal detection of structural congenital heart diseases. Ultrasound Obstet Gynecol. 2003;21(1):19–25. 22. Shima Y, Shindoh F, Nakajima M, et al. Prenatal diagnosis of congenital heart disease: clinical experience and analysis. J Nippon Med Sch. 2004;71(5):328–32. 23. Brosig CL, Whitstone BN, Frommelt MA, et al. Psychological distress in parents of children with severe congenital heart disease: the impact of prenatal versus postnatal diagnosis. J Perinatol. 2007;27(11):687–92. 24. Hyett J, Moscoso G, Nicolaides K. Increased nuchal translucency in trisomy 21 fetuses: relationship to narrowing of the aortic isthmus. Hum Reprod. 1995;10(11):3049–51. 25. Hyett J, Perdu M, Sharland G, et al. Using fetal nuchal translucency to screen for major congenital cardiac defects at 10-14 weeks of gestation: population based cohort study. BMJ. 1999;318(7176):81–5. 26. Rudolph AM. Congenital Disease of the Heart. Armonk, NY: Futura; 2001. 27. Lind J, Stern L, Wegelius C. Human Foetal and Neonatal Circulation. Springfield, IL: CC Thomas; 1964. 28. Reuss ML, Rudolph AM, Heymann MA. Selective distribution of microspheres injected into the umbilical veins and inferior venae cavae of fetal sheep. Am J Obstet Gynecol. 1981;141(4):427–32. 29. Edelstone DI, Rudolph AM. Preferential streaming of ductus venosus blood to the brain and heart in fetal lambs. Am J Physiol. 1979;237(6):H724–29. 30. Schmidt KG, Silverman NH, Rudolph AM. Assessment of flow events at the ductus venosus-inferior vena cava junction and at the foramen ovale in fetal sheep by use of multimodal ultrasound. Circulation. 1996;93(4):826–33. 31. Kiserud T. Fetal venous circulation—an update on hemodynamics. J Perinat Med. 2000;28(2):90–6. 32. Sutton MG, Plappert T, Doubilet P. Relationship between placental blood flow and combined ventricular output with gestational age in normal human fetus. Cardiovasc Res. 1991;25(7):603–8.

1557

33. Meijboom EJ, Horowitz S, Valdes-Cruz LM, et al. A Doppler echocardiographic method for calculating volume flow across the tricuspid valve: correlative laboratory and clinical studies. Circulation. 1985;71(3):551–6. 34. Friedman WF. The intrinsic physiologic properties of the developing heart. Prog Cardiovasc Dis. 1972;15(1):87–111. 35. Mahony L, Jones LR. Developmental changes in cardiac sarcoplasmic reticulum in sheep. J Biol Chem. 1986; 261(32):15257–65. 36. Smith RS, Comstock CH, Lorenz RP, et al. Maternal diabetes mellitus: which views are essential for fetal echocardiography? Obstet Gynecol. 1997;90(4 Pt 1):575–9. 37. Shields LE, Gan EA, Murphy HF, et al. The prognostic value of hemoglobin A1c in predicting fetal heart disease in diabetic pregnancies. Obstet Gynecol. 1993;81(6):954–7. 38. Albert TJ, Landon MB, Wheller JJ, et al. Prenatal detection of fetal anomalies in pregnancies complicated by insulindependent diabetes mellitus. Am J Obstet Gynecol. 1996; 174(5):1424–8. 39. Gladman G, McCrindle BW, Boutin C, et al. Fetal echocardiographic screening of diabetic pregnancies for congenital heart disease. Am J Perinatol. 1997;14(2):59–62. 40. Odibo AO, Coassolo KM, Stamilio DM, et al. Should all pregnant diabetic women undergo a fetal echocardiography? A cost-effectiveness analysis comparing four screening strategies. Prenat Diagn. 2006;26(1):39–44. 41. Bernard LS, Ramos GA, Fines V, et al. Reducing the cost of detection of congenital heart disease in fetuses of women with pregestational diabetes mellitus. Ultrasound Obstet Gynecol. 2009;33(6):676–82. 42. Phoon CK, Kim MY, Buyon JP, et al. Finding the “PR-fect” solution: what is the best tool to measure fetal cardiac PR intervals for the detection and possible treatment of early conduction disease? Congenit Heart Dis. 2012;7(4):349–60. 43. Bajoria R, Wigglesworth J, Fisk NM. Angioarchitecture of monochorionic placentas in relation to the twin-twin transfusion syndrome. Am J Obstet Gynecol. 1995; 172(3): 856–63. 44. Lougheed J, Sinclair BG, Fung Kee Fung K, et al. Acquired right ventricular outflow tract obstruction in the recipient twin in twin-twin transfusion syndrome. J Am Coll Cardiol. 2001;38(5):1533–8. 45. Michelfelder E, Gottliebson W, Border W, et al. Early manifestations and spectrum of recipient twin cardiomyopathy in twin-twin transfusion syndrome: relation to Quintero stage. Ultrasound Obstet Gynecol. 2007;30(7): 965–71. 46. Quintero RA, Morales WJ, Allen MH, et al. Staging of twin-twin transfusion syndrome. J Perinatol. 1999;19 (8 Pt 1):550–5. 47. Rychik J, Tian Z, Bebbington M, et al. The twin-twin transfusion syndrome: spectrum of cardiovascular abnormality and development of a cardiovascular score to assess severity of disease. Am J Obstet Gynecol. 2007;197(4):392. e1–392.e8.

1558


48. Senat MV, Deprest J, Boulvain M, et al. Endoscopic laser surgery versus serial amnioreduction for severe twin-totwin transfusion syndrome. N Engl J Med. 2004;351(2): 136–44. 49. Habli M, Livingston J, Harmon J, et al. The outcome of twintwin transfusion syndrome complicated with placental insufficiency. Am J Obstet Gynecol. 2008;199(4):424 e1– 424.e6. 50. Wong AE, Sepulveda W. Acardiac anomaly: current issues in prenatal assessment and treatment. Prenat Diagn. 2005;25(9):796–806. 51. Mahle WT, Rychik J, Tian ZY, et al. Echocardiographic evaluation of the fetus with congenital cystic adenomatoid malformation. Ultrasound Obstet Gynecol. 2000;16(7): 620–4. 52. McAuliffe FM, Trines J, Nield LE, et al. Early fetal echocardiography–a reliable prenatal diagnosis tool. Am J Obstet Gynecol. 2005;193(3 Pt 2):1253–9. 53. Bhat AH, Kehl DW, Tacy TA, et al. Diagnosis of tetralogy of Fallot and its variants in the late first and early second trimester: details of initial assessment and comparison with later fetal diagnosis. Echocardiography. 2013;30(1):81–7. 54. International Society for Ultrasound in Obstetrics and Gynecology. Cardiac screening examination of the fetus: guidelines for performing the ‘basic’ and ‘extended basic’ cardiac scan. Ultrasound Obstet Gynecol. 2006;27:107–13. 55. Rychik J, Ayres Nm Cuneo B, et al. American Society of Echocardiography guidelines and standards for performance of the fetal echocardiogram. J Am Soc Echocardiogr. 2004;17:803–10. 56. Cordes TM, O’Leary PW, Seward JB, et al. Distinguishing right from left: a standardized technique for fetal echocardiography. J Am Soc Echocardiogr. 1994;7(1): 47–53. 57. Shipp TD, Bromley B, Hornberger LK, et al. Levorotation of the fetal cardiac axis: a clue for the presence of congenital heart disease. Obstet Gynecol. 1995;85(1):97–102. 58. Sharland GK, Allan LD. Normal fetal cardiac measurements derived by cross-sectional echocardiography. Ultrasound Obstet Gynecol. 1992;2(3):175–81. 59. Tan J, Silverman NH, Hoffman JI, et al. Cardiac dimensions determined by cross-sectional echocardiography in the normal human fetus from 18 weeks to term. Am J Cardiol. 1992;70(18):1459–67. 60. Schneider C, McCrindle BW, Carvalho JS, et al. Development of Z-scores for fetal cardiac dimensions from echocardiography. Ultrasound Obstet Gynecol. 2005;26(6): 599–605. 61. Eidem BW, Edwards JM, Cetta F. Quantitative assessment of fetal ventricular function: establishing normal values of the myocardial performance index in the fetus. Echocardiography. 2001;18(1):9–13. 62. Natarajan S, Szwast A, Tian Z, et al. Right ventricular mechanics in the fetus with hypoplastic left heart syndrome. J Am Soc Echocardiogr. 2013;26(5):515–20. 63. Simpson JM, Sharland GK. Natural history and outcome of aortic stenosis diagnosed prenatally. Heart. 1997;77(3): 205–10.

64. Hornberger LK, Sanders SP, Rein AJ, et al. Left heart obstructive lesions and left ventricular growth in the midtrimester fetus. A longitudinal study. Circulation. 1995;92(6):1531–8. 65. Hornberger LK, Trines J. Evolution of congenital heart disease in utero. Pediatr Cardiol. 2004;25:287–98. 66. Hornberger LK, Need L, Benacerraf BR. Development of significant left and right ventricular hypoplasia in the second and third trimester fetus. J Ultrasound Med. 1996; 15(9):655–9. 67. Mäkikallio K, McElhinney DB, Levine JC, et al. Fetal aortic valve stenosis and the evolution of hypoplastic left heart syndrome: patient selection for fetal intervention. Circulation. 2006;113(11):1401–5. 68. Hornberger LK, Sanders SP, Sahn DJ, et al. In utero pulmonary artery and aortic growth and potential for progression of pulmonary outflow tract obstruction in tetralogy of Fallot. J Am Coll Cardiol. 1995;25(3):739–45. 69. Yoo SJ, Lee YH, Kim ES, et al. Three-vessel view of the fetal upper mediastinum: an easy means of detecting abnormalities of the ventricular outflow tracts and great arteries during obstetric screening. Ultrasound Obstet Gynecol. 1997;9(3):173–82. 70. Maulik D, Saini VD, Nanda NC, et al. Doppler evaluation of fetal hemodynamics. Ultrasound Med Biol. 1982;8(6): 705–10. 71. Tulzer G, Gudmundsson S, Sharkey AM, et al. Doppler echocardiography of fetal ductus arteriosus constriction versus increased right ventricular output. J Am Coll Cardiol. 1991;18(2):532–6. 72. Schmidt KG, Birk E, Silverman NH, et al. Echocardiographic evaluation of dilated cardiomyopathy in the human fetus. Am J Cardiol. 1989;63(9):599–605. 73. Simpson JM, Cook A. Repeatability of echocardiographic measurements in the human fetus. Ultrasound Obstet Gynecol. 2002;20(4):332–9. 74. Gonçalves LF, Espinoza J, Romero R, et al. Four-dimensional fetal echocardiography with spatiotemporal image correlation (STIC): a systematic study of standard cardiac views assessed by different observers. J Matern Fetal Neonatal Med. 2005;17(5):323–31. 75. Bhat AH, Corbett V, Carpenter N, et al. Fetal ventricular mass determination on three-dimensional echocardiography: studies in normal fetuses and validation experiments. Circulation. 2004;110(9):1054–60. 76. Huhta JC. Fetal congestive heart failure. Semin Fetal Neonatal Med. 2005;10(6):542–52. 77. Rizzo G, Arduini D, Romanini C. Doppler echocardiographic assessment of fetal cardiac function. Ultrasound Obstet Gynecol. 1992;2(6):434–45. 78. Carceller-Blanchard AM, Fouron JC. Determinants of the Doppler flow velocity profile through the mitral valve of the human fetus. Br Heart J. 1993;70(5):457–60. 80. Tulzer G, Khowsathit P, Gudmundsson S, et al. Diastolic function of the fetal heart during second and third trimester: a prospective longitudinal Doppler-echocardiographic study. Eur J Pediatr. 1994;153(3):151–4.


81. Mäkikallio K, Vuolteenaho O, Jouppila P, et al. Ultrasonographic and biochemical markers of human fetal cardiac dysfunction in placental insufficiency. Circulation. 2002; 105(17):2058–63. 82. Hernandez-Andrade E, Figueroa-Diesel H, Kottman C, et al. Gestational-age-adjusted reference values for the modified myocardial performance index for evaluation of fetal left cardiac function. Ultrasound Obstet Gynecol. 2007;29(3):321–5. 83. Friedman D, Buyon J, Kim M, et al. Fetal cardiac function assessed by Doppler myocardial performance index (Tei Index). Ultrasound Obstet Gynecol. 2003; 21(1):33–6. 84. Meriki N, Welsh AW. Technical considerations for measurement of the fetal left modified myocardial performance index. Fetal Diagn Ther. 2012;31(1):76–80. 85. Van Mieghem T, Gucciardo L, Lewi P, et al. Validation of the fetal myocardial performance index in the second and third trimesters of gestation. Ultrasound Obstet Gynecol. 2009;33(1):58–63. 86. Donofrio MT, Bremer YA, Schieken RM, et al. Autoregulation of cerebral blood flow in fetuses with congenital heart disease: the brain sparing effect. Pediatr Cardiol. 2003;24(5):436–43. 87. Clark JM, Case CL. Fetal arrhythmias. In: Gillete PC, Garson A, editors. Clinical Pediatric Arrhythmias. 2nd ed. Philadelphia: WB Saunders; 1999:293–302. 88. Matias A, Montenegro N, Areias JC, et al. Haemodynamic evaluation of the first trimester fetus with special emphasis on venous return. Hum Reprod Update. 2000;6(2):177–89. 89. Wheeler T, Murrills A. Patterns of fetal heart rate during normal pregnancy. Br J Obstet Gynaecol. 1978;85(1):18–27. 90. Carvalho JS, Prefumo F, Ciardelli V, et al. Evaluation of fetal arrhythmias from simultaneous pulsed wave Doppler in pulmonary artery and vein. Heart. 2007;93(11):1448–53. 91. Fouron JC. Fetal arrhythmias: the Saint-Justine hospital experience. Prenat Diagn. 2004;24(13):1068–80. 92. Kleinman CS, Nehgme RA. Cardiac arrhythmias in the human fetus. Pediatr Cardiol. 2004;25(3):234–51. 93. Southall DP, Richards J, Hardwick RA, et al. Prospective study of fetal heart rate and rhythm patterns. Arch Dis Child. 1980;55(7):506–11. 94. Krapp M, Kohl T, Simpson JM, et al. Review of diagnosis, treatment, and outcome of fetal atrial flutter compared with supraventricular tachycardia. Heart. 2003;89(8): 913–17. 95. Krapp M, Baschat AA, Gembruch U, Geipel A, Germer U. Flecainide in the intrauterine treatment of fetal supraventricular tachycardia. Ultrasound Obstet Gynecol. 2002;19(2):158–64. 96. Oudijk MA, Ruskamp JM, Ververs FF, et al. Treatment of fetal tachycardia with sotalol: transplacental pharmacokinetics and pharmacodynamics. J Am Coll Cardiol. 2003;42(4): 765–70. 97. Merriman JB, Gonzalez JM, Rychik J, et al. Can digoxin and sotalol therapy for fetal supraventricular tachycardia and hydrops be successful? A case report. J Reprod Med. 2008;53(5):357–9.

1559

98. Strasburger JF, Cuneo BF, Michon MM, et al. Amiodarone therapy for drug-refractory fetal tachycardia. Circulation. 2004;109(3):375–9. 99. Buyon JP, Hiebert R, Copel J, et al. Autoimmune-associated congenital heart block: demographics, mortality, morbidity and recurrence rates obtained from a national neonatal lupus registry. J Am Coll Cardiol. 1998;31(7):1658–66. 100. Jaeggi ET, Hornberger LK, Smallhorn JF, et al. Prenatal diagnosis of complete atrioventricular block associated with structural heart disease: combined experience of two tertiary care centers and review of the literature. Ultrasound Obstet Gynecol. 2005;26(1):16–21. 101. Friedman DM, Kim MY, Copel JA, et al. PRIDE Investigators. Utility of cardiac monitoring in fetuses at risk for congenital heart block: the PR Interval and Dexamethasone Evaluation (PRIDE) prospective study. Circulation. 2008;117(4):485–93. 102. Jaeggi ET, Fouron JC, Silverman ED, et al. Transplacental fetal treatment improves the outcome of prenatally diagnosed complete atrioventricular block without structural heart disease. Circulation. 2004;110(12):1542–8. 103. Makino S, Yonemoto H, Itoh S, et al. Effect of steroid administration and plasmapheresis to prevent fetal congenital heart block in patients with systemic lupus erythematosus and/or Sjögren’s syndrome. Acta Obstet Gynecol Scand. 2007;86(9):1145–6. 104. Beinder E, Grancay T, Menéndez T, et al. Fetal sinus bradycardia and the long QT syndrome. Am J Obstet Gynecol. 2001;185(3):743–7. 105. Abramowicz JS, Kossoff G, Marsál K, et al. Literature review by the ISUOG Bioeffects and Safety Committee. Ultrasound Obstet Gynecol. 2002;19(3):318–19. 106. Miller MW, Brayman AA, Abramowicz JS. Obstetric ultrasonography: a biophysical consideration of patient safety—the “rules” have changed. Am J Obstet Gynecol. 1998;179(1):241–54. 107. Kurjak A. Are color and pulsed Doppler sonography safe in early pregnancy? J Perinat Med. 1999;27(6):423–30. 108. International Society of Ultrasound in Obstetrics and Gynecology (ISUOG). Safety statement, 2000. Ultrasound Obstet Gynecol. 2000;16:594–6. 109. Yagel S, Cohen SM, Achiron R. Examination of the fetal heart by five short-axis views: a proposed screening method for comprehensive cardiac evaluation. Ultrasound Obstet Gynecol. 2001;17(5):367–9. 110. Chaoui R, Heling KS. New developments in fetal heart scanning: three- and four-dimensional fetal echocardiography. Semin Fetal Neonatal Med. 2005;10(6):567–77. 111. Maulik D, Nanda NC, Hsiung MC, Youngblood JP. Doppler color flow mapping of the fetal heart. Angiology. 1986; 37(9):628–32. 112. Chaoui R, Hoffmann J, Heling KS. Three-dimensional (3D) and 4D color Doppler fetal echocardiography using spatiotemporal image correlation (STIC). Ultrasound Obstet Gynecol. 2004;23(6):535–45. 113. Maulik D, Nanda NC, Singh V, et al. Live three-dimensional echocardiography of the human fetus. Echocardiography. 2003;20(8):715–21.

1560


114. Volpe P, Campobasso G, Stanziano A, et al. Novel application of 4D sonography with B-flow imaging and spatio-temporal image correlation (STIC) in the assessment of the anatomy of pulmonary arteries in fetuses with pulmonary atresia and ventricular septal defect. Ultrasound Obstet Gynecol. 2006;28(1):40–6. 115. Bord A, Vlasky DV, Rosenak D, et al. B-flow modality combined with STIC in the evaluation of malalignment of the great vessels. Ultrasound Obstet Gynecol. 2006; 28:447. 116. Bord A, Rosenak D, Vlasky DV, et al. B-flow modality combined with STIC in the evaluation of fetal venous anomalies. Ultrasound Obstet Gynecol. 2006;28:556–7. 117. Yagel S, Cohen SM, Shapiro I, et al. 3D and 4D ultrasound in fetal cardiac scanning: a new look at the fetal heart. Ultrasound Obstet Gynecol. 2007;29(1):81–95. 118. Carvalho JS, Moscoso G, Tekay A, et al. Clinical impact of first and early second trimester fetal echocardiography on high risk pregnancies. Heart. 2004;90(8):921–6.

119. Marshall AC, van der Velde ME, Tworetzky W, et al. Creation of an atrial septal defect in utero for fetuses with hypoplastic left heart syndrome and intact or highly restrictive atrial septum. Circulation. 2004;110(3):253–8. 120. Tworetzky W, Wilkins-Haug L, Jennings RW, et al. Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome: candidate selection, technique, and results of successful intervention. Circulation. 2004;110(15):2125–31. 121. Tulzer G, Arzt W, Franklin RC, et al. Fetal pulmonary valvuloplasty for critical pulmonary stenosis or atresia with intact septum. Lancet. 2002;360(9345):1567–8. 122. Gardiner HM, Kumar S. Fetal cardiac interventions. Clin Obstet Gynecol. 2005;48(4):956–63. 123. Gardiner HM. In-utero intervention for severe congenital heart disease. Best Pract Res Clin Obstet Gynaecol. 2008;22(1):49–61.

1561

CHAPTER 72 M-Mode and Two-Dimensional Echocardiography in Congenital Heart Disease Neeraj Awasthy, Savitri Shrivastava

Snapshot  PaƟent PreparaƟon  Imaging  Dextrocardia  Principles of SequenƟal Chamber Analysis  General Features: Shunt Lesions  Atrial Septal Defects  Ventricular Septal Defect  Patent Ductus Arteriosus  Aortopulmonary Window  Gerbode Defect  Atrioventricular Septal Defects  Congenital Anomalies of Mitral Valve  Congenital AbnormaliƟes of Tricuspid Valve  Valvular AorƟc Stenosis  Subvalvular AorƟc Stenosis  Supravalvular AorƟc Stenosis  AorƟc RegurgitaƟon  Sinus of Valsalva Aneurysm  Aortocameral CommunicaƟons  AorƟc Override

 Double Outlet Right Ventricle  Truncus Arteriosus  TransposiƟon of Great Vessels (TGA)  Atrioventricular and Ventricoarterial Discordance  Normal Flow PaƩern of Pulmonary Veins  Anomalies of Pulmonary Veins  Total Anomalous Pulmonary Venous ConnecƟon  Anomalies of Systemic Veins  Coronary Artery Anomalies  Coronary Arteriovenous Fistula  Coronary Aneurysms  Abnormal FormaƟon of Arch  CoarctaƟon of Aorta (CoA)  InterrupƟon of AorƟc Arch  AorƟc Aneurysm  Univentricular Atrioventricular ConnecƟons  Tricuspid Atresia  Mitral Atresia and HypoplasƟc LeŌ Heart Syndrome  Heterotaxy Syndrome

1562


PART 1: BASICS OF IMAGING AND SEQUENTIAL SEGMENTAL ANALYSIS Echocardiography is the most useful modality of imaging in the diagnosis of congenital heart disease (CHD). The following special issues should be remembered while performing pediatric echocardiography:

PATIENT PREPARATION1–4 Prior to taking the patient for an echocardiographic study, all the available clinical data should be carefully perused and the oxygen saturation checked. This helps in total evaluation of lesions. Pediatric echocardiographic examination should be performed when the child is quiet and cooperative or else one may miss certain important observations. In a crying baby alter intrathoracic pressures resulting in fallacious gradients and other vital findings. Most of the neonates and infants can be quietened by a feed, handling by an experienced nurse, using a pacifier, and keeping them adequately warm. Wrapping a small child is in itself not only a proper positioning method for small children and infants but a cuddled up wrapped infant can be easily quietened for a proper echocardiographic examination (Fig. 72.1). Certain children can also remain quiet by familiarizing them with the surroundings and a friendly environment with some

toys and music. A cheerful environment, interaction with the patient, allowing the parents to be around, and familiarizing the patient with equipment are a few factors that help in achieving the child’s cooperation. Sedation may be appropriate if the above methods fail. Sedation should be given in the presence of a parent or a relative with whom the child is familiar. This helps in the acceptance of the drug and gives a better sedative effect. Also, a familiar parent is able to detect changes in the sensorium of the patient. Drugs commonly used are oral chloral hydrate and nasal midazolam. Chloral hydrate is given in a dose of 50 to 100 mg/kg weight (the total dose should not exceed 1.5 g).1 Children may become restless and agitated with chloral hydrate. This usually occurs when the medicine is given when they have just woken from sleep or are hungry. Midazolam nasal drops can also be used in infants and young children (up to 3 years), with a dose of 0.2 mg/kg bodyweight in the nostrils.2,5,6 If the patient does not go to sleep or becomes uncooperative, the same dose can be repeated. Many patients do not fall asleep with midazolam but become passive, cooperative, and drowsy; thus, the study can be performed. The other important aspect is patience. It is rewarding to patiently wait till the child quietens down and then proceed with

Fig. 72.1: The steps for appropriately wrapping up an infant for proper cardiac evaluation. Cuddled up neonate is well suited and cooperative for any echocardiographic examination. Step1: Laying the sheet with single fold on a flat surface (bed); Step 2: Demonstrates the end, which is picked up and wrapped on the baby’s opposite feet; Step 3: Demonstrates step 2 on the baby; Step 4: Wrapping the left over upper end of the sheet on the upper limb; Step 5: Repeating the step of wrapping the upper arm for the other arm; Step 6: Child with restrained both upper limbs; Step 7 and Step 8: The lower part of the sheet is wrapped around the lower limbs to cuddle up the child.

Chapter 72: M-Mode and Two-Dimensional Echocardiography in Congenital Heart Disease

the study. In sedated babies, oxygen saturation should be monitored during the study. There is a wide variation in the age of the patients with CHD, as such transducers of different sizes are needed. In cardiac imaging the sound waves travel through the chest wall, pericardium, and cardiac structures. A portion of the energy is absorbed and the rest is transmitted. The absorption increases with frequency; therefore, a high frequency ultrasound beam, that is, 10 MHz will not penetrate as far as a low frequency transducer like a 2.0 MHz frequency will. This is one of the reasons why high frequency transducers are needed for the new born and infants while low frequency transducers are used for grown up children and adults.3 For small and premature infants, a 12 MHz transducer is used. It has excellent near-field axial and lateral resolution. However, its ability to penetrate the far field is limited. For optimal resolution of the image, the highest frequency transducer should be tried first. If penetration is not adequate, progressively lower frequency transducers can be used till an optimal image is obtained. Multiple transducers may be used in the same patient for optimal imaging. For subcostal imaging generally a transducer with a lower frequency than used for transthoracic imaging gives better results. The probe transducers which are commonly used for pediatric echocardiographic are generally as per the age group of the patient. While a 12 MHz probe transducer is used for small children, a transducer with a frequency range from 5 MHz to 8 MHz is used for grownup children and adolescents. In adults, a lower frequency probe transducer (4–5 MHz) is generally used.

pulsed and continuous wave Doppler, velocities across all valves are recorded. If any unusual turbulence on CFI is noted, it should be carefully interrogated using pulsed and continuous wave Doppler. Conventional views for echocardiography are detailed below.1,2,4-8 Because of the limitations imposed by the air-filled lungs and bony thoracic structures, the echocardiographic planes for the heart are obtained from only four areas of the body (Table 72.1): • Subcostal. • The cardiac apex—apical four-chamber (4C) views. • Parasternal region—adjacent to sternum—second, third, and fourth intercostal spaces. • Suprasternal notch.

Subcostal Window7 Evaluation of congenital heart lesions generally starts with the subcostal view. This provides information regarding the situs, which is a crucial step in the diagnosis of CHD. Imaging the inferior vena cava (IVC) and abdominal aorta in cross section gives this information (Fig. 72.2). In small infants if the transducer is pressed too deep, impairment of respiration may occur. Intensive pressure may also compress on the IVC impairing the venous return. At times, it may lead to nonvisualization of an otherwise patent IVC. The pulsations, color flow mapping, and pulse Doppler interrogation identifies the IVC and the aorta. Table 72.1: Conventional Views of Echocardiography

IMAGING The anatomical reference for the echocardiographic planes is the major axis of the heart and not the major axis of the body. Displaying images in an anatomically correct fashion allows better understanding of anatomy, particularly in cases of complex CHD. For an anatomically correct display, the apex of the imaging sector is placed at the bottom of the screen in the subcostal and the apical views, and for the rest of the views it is placed at the top of the screen. The aim of the study is to image all structures of the heart and great vessels in all possible planes so that one can get a three-dimensional image from the twodimensional (2D) study. The study should be performed in a systematic sequence in all patients so as to minimize errors in diagnosis. In each plane, the transducer should be swept across the heart and great vessels in a specific direction with and without color flow imaging (CFI). Using

1563

Subcostal Sagittal (B1 caval) Coronal Paracoronal view Apical 4C view 5C view with aorta 5C view with pulmonary artery Parasternal Parasternal long-axis view Psax ( parasternal short-axis view) High parasternal short-axis view (ductal view) Suprasternal windows Long-axis view Short-axis view

1564


The position of the heart in the thorax is best appreciated in the subcostal views, which is helpful in planning the whole study. This view also shows the movements of both domes of the diaphragm, any pleural collections, and the position of the liver.

Fig. 72.2: Two-dimensional echocardiography. Subcostal shortaxis at the level of abdominal vessels. Inferior vena cava and aorta are shown in cross section with aorta (red) to left of spine and inferior vena cava (blue) to right of spine (*).

A

D1 Figs 72.3A to E

Following this, one proceeds to image other cardiac structures from the subcostal view (Figs 72.3A to F). The interatrial septum is viewed in the sagittal plane (Bicaval view) with the transducer placed below the xiphisternum. This approach helps to view the flap of foramen ovale, superior vena cava (SVC), IVC, and both right upper and lower pulmonary veins. Their connection can be identified; color flow mapping and pulse Doppler interrogation of these veins are done to rule out any obstruction. In venous obstruction, the first to get altered is the loss of phasic character of venous flow; later, the total velocity also increases. The atrial septum should also be imaged in coronal plane so as to profile the atrial septum completely. Then sweep in the sagittal plane at the level of the ventricular septum, atrioventricular (AV) valves, and great vessels. The sweeps will profile the right ventricle (RV), RV out flow and pulmonary arteries (with a straight anterior tilt), interventricular septum, left ventricle (LV) and left ventricular out flow tract from right to left, AV valves and the great vessels, then the operator should proceed with the coronal section of the ventricle and the out flow tract by tilting the plane of transducer posterior to anterior. By giving a counterclockwise rotation to the transducer, one can obtain a paracoronal view showing RV

B

D2

C

E1

E2


F1

F2

F3

F4

1565

Figs 72.3A to F: Two-dimensional echocardiography subcostal window. (A) Subcostal coronal (four-chamber equivalent) view showing interatrial septum, connection of right upper pulmonary vein (RUPV) to left atrium. Descending aorta ( ) in short axis is imaged behind the left atrium; (B) Subcostal coronal view with posterior-to-anterior sweep showing left ventricular outflow tract and aorta with color flow mapping (blue); (C) Far anterior tilting shows right ventricular outflow tract; (D1 and D2) Subcostal paracoronal view with right anterior tilt showing right ventricle (RV) and right ventricular outflow tract. (E1 and E2) Subcostal paracoronal view with color compare showing right ventricular outflow (*) tract, main pulmonary artery, and right pulmonary artery; (F1 to F4) Subcostal sagittal view of the muscular septum with right-to-left sweep. This view demonstrates the short axis of the left ventricle (LV) at the level of the mitral valve with sweep up to the apex of the heart. The color comparison at the scale of “35–36” is especially important to look for a small muscular ventricular septal defect (VSD), especially in the setting of the increased pulmonary artery pressures (not shown in the illustration).

outflow and right pulmonary artery (PA). This view is also very useful to profile perimembranous and subpulmonary areas of interventricular septum. In coronal section, movement of both domes of the diaphragm can be visualized during respiration.

Subsequently, one should proceed with the parasternal apical, long-axis, short-axis, and suprasternal views. These will be detailed later. The sequence may need to be altered in a few children till they are well sedated.

1566


Sagittal view is similar to the left anterior oblique view and paracoronal view is similar to the right anterior oblique view in the angiographic studies. In the sagittal view, one should sweep the transducer from right to left and reverse, and in the coronal view, the sweep should be from the posterior to anterior and reverse, in order to obtain various sections of the heart.

A

B

C

D

Apical View (4C View; Figs 72.4A to D) Apical view is commonly called the four-chamber view or 4C view. The apical impulse corresponds to the site of optimal placement of the probe for 4C view. After obtaining an adequate window from the apex, the transducer should be swept from the posterior to anterior plane and reverse.

Figs 72.4A to D: Two-dimensional transthoracic echocardiography. (A) Apical four-chamber view in posterior plane showing coronary sinus (CS) coursing from left to right in atrioventricular groove; (B) Apical four-chamber view showing all four cardiac chambers, the interatrial septum, and interventricular septum. Offsetting of atrioventricular valves (attachment of tricuspid valve more toward apex than mitral valve—arrow) is seen; (C) Apical four-chamber view in anterior plane (apical five-chamber view) showing left ventricular outflow tract and aorta; (D) Same view in far anterior tilt visualizes right ventricular outflow tract and main pulmonary artery. (Ao: Aorta; CS: Coronary sinus; LA: Left atrium; LV: Left ventricle; MPA: Main pulmonary artery; RA: Right atrium; RV: Right ventricle).


1567

In the most posterior plane, the coronary sinus can be imaged coursing at the base of the left atrium (LA) and opening into right atrium (RA; Fig. 72.4A). The classical 4C view shows all four chambers, AV valves, and the offsetting of AV valves (Fig. 72.4B). With the anterior tilt, the aorta can be seen and on a further anterior tilt the PA can be profiled if the great arteries are normally related (Figs 72.4C and D). The apical five-chamber and two-chamber views are commonly used in adult practice to image various segments of the LV. As the transducer is swept anteriorly from the apical view, image quality deteriorates because of rib shadowing.

Parasternal Long-Axis View (Figs 72.5A to D)

A

B

C

D

This view is obtained with the marker of the probe directed to the right shoulder in the long axis of the heart. The parasternal long-axis (PLAX) view visualizes the RV, the interventricular septum, and LV; by sweeping from left to right, one visualizes the aorta and LA and the LV (Fig. 72.5A). The sweep toward the left and superiorly allows visualization of the RV out flow tract (Fig. 72.5B). The rightward and inferior tilt profiles the tricuspid valve and the adjacent RV inflow (Figs 72.5C and D).

Figs 72.5A to D: Two-dimensional transthoracic echocardiography. (A) Parasternal long-axis view of left ventricle showing the left ventricular inflow and outflow tract with anteriorly placed RV cavity; (B) Parasternal long-axis view with anterior tilt showing right ventricular outflow tract. (C and D) Parasternal long axis with posterior tilt and color compare showing right ventricular inflow. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right atrium; RVOT: Right ventricular outflow tract).

1568


Parasternal short-axis (PSAX) view is obtained with the transducer pointing to the left and probe marker

perpendicular to the PLAX view. Serial cross sections of the heart are obtained, demonstrating various structures by sweeping superiorly and inferiorly. The superior sweeps show the great vessels and the inferior sweeps show serial cross sections of the ventricles from base to apex.

A

B

C

D

Parasternal Short-Axis View (Figs 72.6A to D)

Figs 72.6A to D: Two-dimensional transthoracic echocardiography. (A) Parasternal short-axis view at the base of the heart showing aorta (Ao), right ventricular outflow tract, pulmonary valve, main pulmonary artery, bifurcation of main pulmonary artery, and right and left pulmonary arteries; (B) Parasternal short-axis view of left ventricle at the level of the mitral valve showing the anterior mitral leaflet (arrow) and the posterior mitral leaflet (arrow); (C) Parasternal short-axis view of left ventricle at the level of papillary muscle showing the location of papillary muscles, anterolateral at 4 o’clock and posteriomedial at 8 o’clock, trabecular part of interventricular septum, and right ventricular cavity; (D) Parasternal short-axis view toward apical part of ventricular septum. (LPA: Left pulmonary artery; LV: Left ventricle; MPA: Main pulmonary artery; RPA: Right pulmonary artery; RV: Right ventricle).


Parasternal Short-Axis View for Coronary Arteries (Fig. 72.7)1,2,8 The coronary arteries are better visualized with higher frequency transducers in PSAX views at the level of aortic cusps. Using zoom and low color flow gain, one should check the color flow in both coronary arteries. The right coronary artery (RCA) is at a more superior plane, hence the transducer needs to be rotated counterclockwise, and for the left coronary artery (LCA) a clockwise rotation of the transducer is required. The origin of both the coronary

1569

arteries can usually be visualized. The coronary arteries can also be visualized from a subcostal window in the coronal view of left ventricular out flow.

High Parasternal or Ductal View (Fig. 72.8) The classic short-axis view visualizing the aorta and PA is initially obtained from just below the clavicle, a level higher than the usual parasternal views. From this location, the transducer is rotated anticlockwise. During this process, the right PA gradually goes away from view. The main PA is then seen continuing as the left PA. The descending thoracic aorta then is in view. The duct is located at the junction of left PA with the descending aorta. This is called ductal view.

Suprasternal Views (Figs 72.9 and 72.10) This view is profiled by placing the probe in the suprasternal notch. It is helpful to place a small pillow below the neck to extend the neck.

Long-Axis View (Fig. 72.9)

Fig. 72.7: Two-dimensional echocardiography. Parasternal shortaxis view showing origin of both the right and left coronary arteries. (LCA: Left coronary artery; RCA: Right coronary artery; Ao: Aorta).

Fig. 72.8: Two-dimensional echocardiography. High parasternal short-axis view with anticlockwise tilt to profile ductal area with color flow imaging shows Desc. aorta, main pulmonary artery, and left pulmonary artery in short axis. (AO: Aorta; LPA: Left pulmonary artery; MPA: Main pulmonary artery; Desc. Ao: Desending aorta).

The direction of the marker of the probe is toward the left shoulder. This oblique view profiles the arch and descending aorta lengthwise. In case of right aortic arch, the transducer needs to be rotated anticlockwise to profile the arch and descending aorta.

Fig. 72.9: Two-dimensional echocardiography. Suprasternal long-axis view with color flow mapping showing arch of aorta and descending aorta with arch branches. (A: Transverse arch; Desc. Aorta: Descending aorta).

1570


Fig. 72.10: Two-dimensional echocardiography with color flow compare. Suprasternal short-axis view showing aorta in short axis, right pulmonary artery in long axis and innominate vein joining superior vena cava, all four pulmonary veins joining left atrium. (LA: Left atrium; RPA: Right pulmonary artery; SVC: Superior vena cava; AO: aorta; Inn V: Innominate vein).

Short-Axis View (Fig. 72.10) The direction of probe is parallel to the body plane. This short-axis view profiles the aorta in its short axis and opens up the right PA below the aorta in its entire length till the first branch. Below the right PA, one can see the LA receiving all four pulmonary veins, also called the crab view. By tilting the transducer to left and anteriorly, left PA can be profiled. By tilting the transducer superiorly and to the right, one can profile the innominate vein and the SVC. In the suprasternal notch view try to look for the branching of the arch vessels. If the first branch courses to right and divides it, this indicates a left aortic arch, and if the first branch divides and courses to the left side, it is diagnostic of the right aortic arch.

DEXTROCARDIA For patients with dextrocardia, attempts should be made to perform the same views keeping the transducer on the right side of the chest (Fig. 72.11). The marker on the transducer should point in the same overall direction as for patients without dextrocardia. This enables consistency in image orientation and display.

Fig. 72.11: Two-dimensional echocardiography. Subcostal view showing situs solitus with dextrocardia and L-looped ventricles. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Color Flow Doppler Color is superimposed on 2D images to demonstrate the flow information. While using color flow mapping the 2D image should be idealized and 2D gain reduced.


1571

Table 72.2: Pitfalls in Imaging of Congenital Heart Disease

Chest wall deformities: These are common in patients with congenital heart disease. Thus, pectus excavatum or carinatum produces poor parasternal images. Also, scoliosis causes the heart to shift to the ipsilateral side and produces difficulty in imaging Diaphragmatic hernia: In this condition, the bowel loops can come in front of the chest wall. Since air is a poor conductor of ultrasound, it can cause unexplained difficulties in imaging. The plain X-ray of the chest easily diagnoses the condition The postoperative state: Chest wall edema, bandages, and chest wall drains in the immediate postoperative period and deformity of the sternum in the late postoperative state frequently cause problems in imaging. This is especially true for midline structures. Following the arterial switch and the LeCompte maneuver, the pulmonary artery frequently lies behind the sternum. Similarly, midline structures like conduits may be poorly visualized. Grown up congenital heart disease: It is frequently difficult to get good images in a grown up patient with congenital heart disease. This is especially true for structures like the pulmonary artery, pulmonary and systemic veins, descending thoracic aorta, ductal area, etc. even with use of adult transducer. Associated with the poor window is the inability to get good color flow images or continuous wave Doppler envelopes

A

B

Figs 72.12A and B: Nonoptimal scales can result in overestimation of tricuspid valve regurgitation. (A) Apical four-chamber view showing tricuspid valve regurgitation with splaying of the colors (at color scale of 32); (B) Apical four-chamber view in the same patient showing tricuspid valve regurgitation with no splaying of the colors at color scale of 72.

Red color indicates flow toward the transducer and blue indicates away from the transducer. Color Doppler allows rapid display of a great deal of information. One can easily visualize small disturbed jets and study them in depth. CFI is an extremely useful modality that can considerably improve the speed and accuracy of an echocardiographic examination. If used incorrectly, however, it can result in an erroneous interpretation of information. The echocardiographer needs to be aware of the following pitfalls of CFI to make optimal use of color Doppler (Table 72.2). • Failure to optimize 2D images before using color Doppler results in poor quality color flow images: The echocardiographer should endeavour to obtain maximum possible information from 2D images before using color. This allows CFI to be specifically targeted to areas of interest.

•

•

•

Size of color sector: If the color sector is very large, the frame rate is reduced considerably. This results in poorly defined color flow images with potential for both overestimation and underestimation of lesion severity. The size of color sector should be kept as small as possible. The use of the “zoom” switch allows for improved visualization with the smallest possible size of the color sector. Failure to optimize gain and scale settings (Figs 72.12A and B): Excessive gains can result in overestimation of regurgitant lesions such as mitral, tricuspid and aortic regurgitation. The color Doppler gain should be adjusted in a manner that no color is seen in areas where blood doesnot flow. Failure to optimize color scales (Figs 72.13A and B): Low velocity flows (venous flows, flows in the atria, etc.) are best demonstrated by low color scale settings.

1572


A

B

Figs 72.13A and B: Optimal color gain settings are essential to prevent “graining” in the field of imaging. (A) Four-chamber (inverted view) showing graining in the field of interest with gain settings of 90%; (B) The same patient with trace regurgitation and minimal graining after optimizing color gains.

•

The same settings will overestimate the severity of high velocity regurgitant jets such as aortic regurgitation and mitral regurgitation. Wherever high velocity flows are anticipated, the color scale settings should be appropriately increased. Multiple color jets: Multiple color flow jets require careful interpretation. Examples include multiple ventricular septal defects (VSDs) or a combination of VSD with infundibular pulmonary stenosis. In this situation, some lesions may be missed. Careful attention to 2D images can often resolve the individual lesions.

Interpreting Color Flow Information in Isolation A number of criteria are available for quantification of regurgitation jets by CFI. However, using them in isolation may result in incorrect interpretation of lesion severity. The information obtained on CFI should be combined with the 2D information to improve accuracy. Examples include incorporation of left atrial size, left ventricular size and function while estimating severity of mitral regurgitation, and left ventricular size and function for estimation of severity of aortic regurgitation.

Pulsed Doppler (Figs 72.14A and B) A single ultrasound crystal alternatively transmits and receives the ultrasound signal. The vessels or valve being interrogated is imaged by 2D echocardiography.

The Doppler cursor should be placed in the direction of the flow being interrogated as seen on color flow mapping. There are limits to the maximum frequency shifts that can be unambiguously displaced at any given point; the maximum detectable frequency shift in one direction is one half of the sampling rate. The maximum detectable frequency is called the Nyquist limit. The pulsed Doppler mode selectively provides the flow velocities at the area being interrogated.

Continuous Wave Doppler The continuous wave Doppler transducer has two crystals, one continuously transmits an ultrasound signal whereas the other continuously receives the back-scattered ultrasound; therefore, Doppler signals from all blood flow traversed by the ultrasound beam are received and displayed. The main advantage of plural wave of continuous wave Doppler is that there is no limit to the maximum limits that can be measured. Therefore, very high velocity jets can be correctly interrogated.

Cautions in Using Pulsed and Continuous Wave Doppler Evaluation Poor Echo Windows If the images are suboptimal, Doppler signals are suboptimal as well. The nonimaging continuous wave Doppler probe may be used in selected circumstances, keeping in mind the potential pitfalls of using the nonimaging probe.


A

1573

B

Figs 72.14A and B: (A) Doppler signal with inappropriate gain setting resulting in falsely increased gradients. Note excessive splaying with a gradient of 85 mm Hg; (B) The same patient with optimized gains with a gradient of 51 mm Hg (+).

Inappropriate Transducer Frequency High quality Doppler signal with clear display of high velocity signals requires lower transducer frequencies than those required for optimal images. Serious underestimation of stenotic lesions may result from use of high frequency transducers for obtaining Doppler gradients. This is particularly true for Doppler interrogation of deeper lesions such as coarctation. Whenever possible, gradients obtained during imaging with high frequency transducers should be confirmed by using lower frequency transducers.

Inappropriate Doppler Gain and Filter Settings (Figs 72.12 and 72.13) High velocity signals require high filter settings. For low velocity signals such as venous signals, low filter settings are appropriate. The Doppler gain should be adjusted to minimize signal-to-noise ratio. Increased gain settings result in noisy signals with poorly defined spectral margins. This can result in overestimation of the gradients.

Inappropriate Doppler Scales (Figs 72.14A and B) Aliasing of the signal results when the Doppler scales are inappropriately low. Once aliasing occurs, the signal cannot be accurately quantified. Increasing the scales of the Doppler signals can minimize aliasing. For pulsed Doppler, this would require increasing in the pulse

repetition frequency (PRF). High velocity signals alias despite maximum PRF. For measuring their velocity, continuous wave Doppler will have to be used.

Inappropriate Signal Alignment (Figs 72.15A and B) It is the most common cause of underestimation of Doppler gradients. The correct use of CFI and interrogation in multiple views considerably minimizes the likelihood of poor alignment. For example, in a patient with valvular aortic stenosis the gradient should be obtained in the apical, the right parasternal, and the suprasternal views. The maximum value obtained represents the true Doppler gradient. However, the gain settings should be optimized to get a clear envelope. For a patient with a perimembranous VSD, Doppler signals may have to be recorded in the subcostal, the apical, and the parasternal views to obtain the best aligned signal.

Pitfalls Relating to the Use of the Nonimaging Continuous Wave Doppler Probe There is a likelihood of mistaking one signal for another if the nonimaging probe alone is used for gradient estimation. For example, while interrogating from the apex, the systolic gradient of mitral regurgitation may be mistaken for aortic stenosis. Again, interrogation from multiple views can help reduce the chances of errors.

1574


A

B

Figs 72.15A and B: (A) High frequency signal not getting aligned in view of the pulsed wave Doppler exceeding the Nyquist limit; (B) The same patient by appropriately increasing the scale of the measurements, and changing from pulsed wave to continuous wave Doppler.

Failure to Appreciate the Limitations of the Bernoulli Equation Simply stated, the Bernoulli equation is as follows: Pressure difference between two points = convective acceleration + flow acceleration + viscous friction. Of these three determinants of pressure difference, convective acceleration is considered the most significant. Convective acceleration is defined by the formula 1/2p (V22 − V12); “p” represents the fluid density of blood; V1 and V2 are the velocity of blood at the two points across which the pressure difference is being measured. After converting blood density by using the conversion factor to mm Hg and velocity to m/s, the coefficient calculates out as 3.98. This is rounded to 4. The assumptions that are made while applying the Bernoulli equation to clinical situations are as follows: (a) Flow acceleration and viscous friction are considered negligible; (b) The velocity proximal to the obstruction is negligible as compared to the distal velocity. After making these assumptions, the formula is simplified to: pressure difference = 4 peak instantaneous velocity. (c) The pressure gradients are not calculated in tubular uniform structures. Although this formula has been validated for a number of situations, the assumptions made introduce important limitations to its applications in specific situations. These include serial obstructions where it cannot be assumed that proximal velocity (VI) is negligible. For measuring pressure differences across discrete obstruction within a tubular structure (such as coarctation of the aorta), the VI should be measured and VI should be subtracted from V2. Other examples where V1 may be increased include combined stenotic

and regurgitant lesions, stenotic lesion combined with a shunt lesion [atrial septal defect (ASD) with pulmonary stenosis], and high output states such as anemia. In patients with polycythemia, the viscous friction may be significant and blood density (p) cannot be assumed to be the same as for normal, and in such a situation significant underestimation of Doppler gradients may result.

Pressure Gradients Across Trivial Lesions When the amount of blood flow is very small, such as in tiny muscular VSDs or in trivial tricuspid regurgitation, the pressure gradient may be underestimated by Doppler despite optimal gain setting. This is possibly because the sample volume is too small.

Comparison of Echo Gradients with Those Obtained During Cardiac Catheterization (Fig. 72.16) Peak-to-peak versus peak instantaneous pressure gradients: While interpreting Doppler flow gradients, it is important to remember that Doppler measures the peak instantaneous pressure difference, which is higher than the peak-to-peak pressure difference measured by cardiac catheterization. The relationship between peak instantaneous pressure difference and peak-to-peak pressure difference is complex, possibly because it is determined by a number of influences (such as heart rate, severity of obstruction, dP/dt, etc.). Doppler gradients can exceed gradients recorded by cardiac catheterization by as much as 30 to 40 mm Hg.


Fig. 72.16: The graph demonstrates the comparison of peak instantaneous gradient with peak-to-peak gradient in left ventricular and aortic pressure tracing. The instantaneous pressure gradient is higher than the peak-to-peak gradient.

Failure to Relate the Doppler Gradients to Flows Pressure gradients are influenced by flows. While interpreting gradients recorded by Doppler, the physiological state of the patient needs to taken into consideration. High output states, fever, anxiety, agitation, anemia can all exaggerate gradients. For this reason, it is imperative to record systemic blood pressure (BP) while trying to predict PA pressures using gradients across VSDs. Similarly, while interpreting the severity of stenotic lesions by pressure gradients, the flow across the orifice needs to be considered. Other pathophysiological states that can reduce blood flow include hypovolemia, hypotension, and ventricular dysfunction.

PRINCIPLES OF SEQUENTIAL CHAMBER ANALYSIS9–13 The cardinal principle of sequential chamber analysis states that the morphology of a chamber should be determined on the basis of its most constant component. Thus, one should not use a component to identify a structure if that component itself is variable. The evaluation of any congenital heart involves a systemic sequential analysis that involves the following steps: • Identification of abdominal situs. • Identification of atria and atrial arrangement.

1575

Fig. 72.17: Two-dimensional echocardiography in a patient with situs inversus. Subcostal short-axis view at the level of abdominal vessels showing inferior vena cava and aorta in cross section with aorta (red) to the right of spine, and inferior vena cava (blue) to the left of spine (), reversed position of the liver (toward the left of the spine) and gastric bubble (toward the right of the spine). (Ao: Aorta; V: IVC; Li: Liver; GB: Gastric bubble).

•

Identification of ventricular morphology and AV connection. • Identification of great vessels and ventricular arterial connection. • Identification of associated abnormalities and assessing their severity. The initial step of evaluation starts with the determination of abdominal situs with IVC to the right of the spine and aorta to the left in situs solitus (Fig. 72.3) and vice versa in situs inversus (Fig. 72.17). The atrial situs generally corresponds with the abdominal situs. If the IVC and aorta are on same side of the spine then possibly we are dealing with isomeric heart (Fig. 72.18). The IVC may be interrupted, which will suggest left isomerism (Fig. 72.18).

Identification of Atria and Their Arrangement The next step is to identify the atrial arrangement. Four types of atrial arrangements can exist: • Normal atrial arrangement (Situs solitus)—the RA is right-sided and the LA is left-sided. • Mirror image atrial arrangement (Situs inversus)—the RA is left-sided and the LA is right-sided. • Isomerism of the left atrial appendage. • Isomerism of the right atrial appendage.

1576


Fig. 72.18: Two-dimensional echocardiography. Subcostal shortaxis view at the level of abdominal vessels. Inferior vena cava and aorta are shown in cross-section with aorta (red) and inferior vena cava (blue) to right of spine. Spine (*). (Ao: Aorta; V: IVC).

A

B

Figs 72.19A and B: Two-dimensional echocardiography in subcostal coronal view with superior tilt showing (A) broad-based right atrial appendage (RAA); (B) narrow, finger-like left atrial appendage (LAA).

Identification of Atrium The atrial appendage: It is the most constant feature for atrial identification. The right atrial appendage is a broad triangular structure with a broad junction with the rest of the atrium (Figs 72.19A and B). It has coarse pectinate muscle within the appendage, which extend all around the vestibule of the appendage and atrial junction. The morphological left atrial appendage is tubular with a narrow junction with the rest of the atrium (Fig. 72.20). The posterior wall is smooth, and the pectinate muscle is confined only to the anterior quadrants of the vestibule. Echocardiographically, the shape of atrial appendages is best visualized by a combination of the subcostal coronal view (right and left atrial appendages) and parasternal short axis at great vessel level (left atrial appendage). The pectinate muscles, however, cannot be well identified by

echocardiography. Unfortunately, altered hemodynamics in complex CHD may not allow the appendage to have a classical appearance. The venous drainage: The opening of the suprahepatic portion of the IVC to the RA is the most important marker in identifying morphological RA and can be easily identified on 2D echocardiography in the subcostal long-axis view. The pulmonary venous connection is too variable to be used as a marker for LA. The atrial septum: The septum primum overlaps the septum secundum from the left atrial side and if present, is an important feature in identifying the LA, best visualized in the subcostal sagittal view. Unfortunately, in some complex forms of CHD the atrial septum may be absent and thus this feature cannot be used as a marker.


1577

left- or right-sided atrium or sometimes in the midline (for those who believe in the isomerism concept, both atria are of same morphology, hence called the right or left isomerism). The atrial appendage morphology would be the most specific marker for atrial identification. Unfortunately, the shape of the appendage (as discussed previously) rarely helps in complex CHD and identification of the atrial pectinate muscle by 2D echocardiography is not usually possible.

Fig. 72.20: Two-dimensional echocardiography. Subcostal sagittal view—bicaval view showing the attachment of suprahepatic portion of inferior vena cava to right atrium. Right pulmonary artery is shown in short axis posterior to superior vena cava (*). (IVC: Inferior vena cava; LA: Left atrium; RA: Right atrium; SVC: Superior vena cava).

The coronary sinus (Fig. 72.5A): The coronary sinus always traverses the floor of the LA and opens into RA. It is a useful marker if present. The apical four-chamber view angled posteriorly profiles this feature well. Aorta–inferior vena cava relation in the abdomen (Fig. 72.3): This indirect method of inferring the atrial morphology is the most popular and easily performed technique by 2D echocardiography. It is very sensitive and specific in patients of normal or mirror image atrial arrangement but less so in the group with isomerism. It is based on the facts that, in patients of normal or mirror image arrangements, the viscera and great vessels in the abdomen are lateralized. The subcostal short-axis scan at the level of diaphragm shows the relation of great vessels and the spine to each other. Thus, in normally arranged atria, the aorta is always to the left of the spine and the IVC to the right, at the level of the diaphragm. This relation is reversed in mirror image arrangement.

Echocardiographic Identification of Isomerism Right and left isomerism should be strongly suspected on echocardiography when the following findings are present. Right Isomerism: Also called the asplenia syndrome, this is strongly suspected on the abdominal scan of the great vessels. The aorta and IVC lie on the same side of the spine (left or right) instead of on either side. The aorta lies posterior to the IVC. The IVC opens into either the

Left isomerism: Also called the polysplenia syndrome, this can also be suspected on the abdominal scan of great vessel. The aorta and a venous channel again lie on the same side of the spine (left or right). The aorta is anterior and the venous channel lies posterior to it. This venous channel actually represents the azygos/hemiazygos vein, which then continues posteriorly through the diaphragm and joins the left (hemiazygos) or right (azygos) SVC. The IVC is interrupted and the hepatic veins connect to the atrium directly. IVC interruption is seen in 85% cases of left isomerism. For those who do not believe in the concept of isomerism, the chamber that receives the coronary sinus/hepatic vein would become the morphological RA. There are other echocardiographic features by which isomerism should be suspected although not diagnostic. • Bilateral SVC. • Absent coronary sinus (in right isomerism or asplenia). • Single atrium. • Total anomalous pulmonary venous connection (TAPVC)—The pattern of TAPVC is different in right and left isomerism. • Total anomalous systemic venous drainage. • Common AV valve. • Discordance between abdominal and atrial situs.

Ventricular Morphology and Atrioventricular Connection The connection of the atrial myocardium to the ventricular mass is called the AV connection. The following types of connections are recognized (Table 72.3): • Concordant AV connection (Fig. 72.21). • Discordant AV connection (Fig. 72.22). • Univentricular atrioventricular connection (Figs 72.23A and B). • Isomeric AV connection. • Uniatrial and biventricular connection. • Criss-cross AV connection. To describe AV connection, one should identify the ventricular morphology.

1578


Table 72.3: Echocardiographic Identification of Atrioventricular Connection

The offsetting sign and moderator band are best identified by the apical four-chamber view The chordal attachment of the morphological tricuspid valve to the interventricular septum is best seen in the subcostal coronal views The two discrete papillary muscles of left ventricle and the apical trabeculations of right ventricle are best appreciated in parasternal short-axis views. The transducer is focused inferiorly starting at the base of the heart. The papillary muscles are first seen followed by the apical trabeculations Absence of an atrioventricular valve, common atrioventricular valve, and straddling are best seen in the apical views. The common atrioventricular orifice is also well appreciated in the subcostal sagittal views

Fig. 72.21: Two-dimensional echocardiography. Apical four-chamber view showing all four cardiac chambers and offsetting of atrioventricular valves (attachment of tricuspid valve more toward apex than mitral valve—arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

Fig. 72.22: Two-dimensional echocardiography. Apical fourchamber view showing discordant atrioventricular connection, right atrium to left ventricle, and left atrium to right ventricle. Moderator band on left side (anatomical right ventricle) and reverse offsetting of atrioventricular valves are seen (arrow).

B

Figs 72.23A and B: Two-dimensional echocardiography. Apical four-chamber view showing univentricular atrioventricular (AV) connection. (A) Tricuspid atresia (arrow), hypoplastic right ventricle; (B) Mitral atresia (arrow), with hypoplastic left ventricle (LV). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).


Echocardiographic Identification of Ventricular Morphology The offsetting sign of atrioventricular valves: This sign, if present, forms the single most important feature in identification of ventricular morphology. It takes into account that the AV valve always follows its ventricle. The tricuspid valve is attached more apically compared to the mitral valve. Thus, a ventricle which has its AV valves attached more apically will be the morphological RV. The disadvantage with this sign is that when a VSD extends to the inlet septum or in univentricular hearts, this “offsetting” sign is lost and therefore cannot be used as a feature for ventricular morphological identification. The ventricular septal and apical trabeculation: The morphologists consider this as the most constant feature of ventricular morphology. The RV apical trabeculations are coarse. The moderator band contributes to this coarseness. The RV side of the septum is seen to be coarser compared to the LV side of the septum. Echocardiographically, this feature becomes difficult to identify if one of the ventricles is severely hypoplastic or there is a true single ventricle. Attachment of the chordae and papillary muscle to the septum: The RV side of the septum gains attachment of the chordae and papillary muscle. The left ventricular side of the septum is always free of chordal attachment. Papillary muscles: The LV has two discrete papillary muscles. The RV has three or more papillary muscles.

Echocardiographic Identification of Atrioventricular Connection •

•

Concordant AV connection: When the LA (whether right- or left-sided) connects to the morphological LV and the RA (right- or left-sided) connects to the morphological RV. Discordant AV connection: When the LA (whether right- or left-sided) connects to the RV and the morphological RA (right- or left-sided) connects to the morphologic LV.

Identification of Great Vessels and Ventricular Arterial Connection Echocardiographic identification of great vessel connection to the ventricular mass is evaluated in the following steps.

1579

Identification of Great Vessels The PA is identified by its immediate bifurcation into left and right branches. This is best appreciated in the PSAX view at great vessel level. Other clues are: (a) In the PLAX view if the posterior great vessel is seen coursing posteriorly after its origin the vessel is the PA. The aorta always takes an anterior course. (b) Annular hypoplasia is often the rule in patients with pulmonary stenosis physiology (like tetralogy etc.). Then the vessel with a smaller annulus and with turbulent flow (on color or pulsed Doppler) is often the PA. (c) The aorta does not give rise to any branch before the carotids across the coronaries and it gives rise to the arch vessels. The coronary arteries are useful pointers to identify aorta, but because of their variable origin (e.g. the PA) they cannot be used as a criterion for a great vessel to be labeled as the aorta.

Identification of Connection of Great Vessels A combination of views are used to identify great vessels and their connection. Starting from the subcostal coronal scan, the transducer is tilted superiorly in a gradual fashion. The great vessels appear sequentially as the transducer is tilted superiorly, the posterior great vessel is seen first and then the anterior great vessel. During this process, the great vessel connections with the ventricles can also be identified. Apical view—As the transducer is tilted superiorly from the level of AV valves to the great vessel, the connection with the ventricles can be identified. PLAX view—In this view if the two vessels can be clearly seen in the same plane and have a side-by-side relation, the two great vessels are likely to be transposed. Not only the continuity of the ventricle with the great vessels is identified in this view, but also the degree of override [to classify the anatomy, for example, double outlet right ventricle (DORV)] can be assessed in this view. Univentricular atrioventricular connection: When both the atria connect predominantly to one ventricle it is called the univentricular connection. Most often the other ventricle can be identified echocardiographically and is rudimentary. Rarely one can have true absence of another ventricle (true single ventricle). The atria can connect to one ventricle by two valves (double inlet ventricle, common AV valve, or a single AV valve, the other valve being absent like in mitral or tricuspid atresia). When two AV valves are committed to one main ventricular mass there can be a wide spectrum of commitment. At one end,

1580


both AV valves are completely committed to one ventricle, the other ventricle being devoid of an inlet. Then there can be a varying degree of commitment of one AV valve to the dominant ventricle. In such cases, the 50% rule is used, wherein, if one AV valve is committed more than 50% to a ventricle, then it is ascribed to that ventricle. The reason for commitment is due to straddling/overriding of a valve through the VSD. Overriding refers to the AV valve annulus and straddling occurs when the tensor apparatus crosses over to the contralateral ventricle. Usually both exist together but each can be independent of the other. Tricuspid valve always straddles through an inlet VSD and the mitral valve through an outlet VSD. Isomeric atrioventricular connection: This terminology is used by the group, which believes in the concept of isomerism. In such cases, since both atria are isomeric (right or left), the connection cannot be concordant or discordant as per definition. Subsequent description of the ventricles is done by using the loop method (discussed later). Uniatrial and biventricular connection: In these cases one AV junction is absent but the other AV junction overrides the ventricular septum with the valve of this junction straddling both ventricles, thereby creating a biventricular connection.

Atrioventricular Connections and the Loop Rule In the presence of concordant AV connection in normally arranged atria, there will always be a D-loop (or right hand topology), and in the presence of discordant AV connection in normally arranged atria, it will always be an L-loop (or left hand topology). The reverse applies in patients of mirror image atrial arrangement (L-loop in concordant AV connection and D-loop with discordant AV connection). There are descriptions of hearts with concordant AV connections with normally arranged atria but with an L-loop and also vice versa. Thus, although in the majority of cases the loop rule holds true and can be inferred, it was felt necessary to mention the loop in the sequential description of congenitally malformed heart because of these rare examples. Also, in criss-cross AV connections, there may be normally arranged atria and AV concordance with L-looped ventricles. D-Loop (right hand topology): It implies that the RV is to the right of the LV in normally arranged atria and vice versa in mirror-imaged atria.

L-Loop (left hand topology): It implies that the RV is to the left of the LV in normally arranged atria and vice versa in mirror imaged atria. These features can be easily made out by 2D echocardiography.

Ventriculoarterial Connection The ventriculoarterial connections can be divided into the following types: • Concordant ventriculoarterial connection. • Discordant ventriculoarterial connection. • Double outlet ventricle (right or left). • Single outlet—pulmonary atresia, aortic atresia. • Common outlet.

Concordant Ventriculoarterial Connection The LV is connected to the aorta and the RV to the PA. Discordant ventriculoarterial connection (Fig. 72.24): The LV is connected to the PA and the RV to the aorta. It is also called transposition of great arteries. Double outlet ventricle (Fig. 72.25): (1) Double Outlet Right Ventricle—When the PA and > 50% of the aorta [the VSD type] or the aorta and > 50% of the PA (the transposition type) arises from the RV, it is called DORV. Some authors would define DORV only when > 90% of a vessel is committed to the ventricle. The present definition of DORV is based on connections of the great vessel to the ventricle. Some groups of authors feel that double outlet ventricle should be defined only

Fig. 72.24: Two-dimensional echocardiography. Parasternal longaxis view showing ventriculoarterial discordance. (AO: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).


in terms of the conal morphology. Thus, these groups of workers would define DORV only when there is bilateral coni, that is, there is aortomitral and tricuspid pulmonary or mitral pulmonary and tricuspid aortic discontinuity. (2) Double Outlet Left Ventricle (Fig. 72.26)—When the aorta and >50% of the PA or PA and >50% of aorta arise from the LV, it is called double outlet left ventricle (DOLV). In this condition, there is bilateral absence of the conus, that is, both the semilunar valves are in continuity with the AV valves.

1581

ventricle and the other great vessel is atretic and cannot be traced to the ventricular mass. The commonest in this group is pulmonary atresia. The echocardiographer needs to distinguish between an absent connection and an imperforate valve. In the latter, there is a potential communication between the great vessel and the ventricle and therefore can be designated as concordant or discordant connection.

Single outlet (Figs 72.27A and B): This is recognized when there is only one great vessel arising from the

Common outlet (Figs 72.28A and B): In this condition, a common trunk arises from the ventricles and gives rise to aorta, PA, and the coronaries. It is also called the truncus arteriosus.

Fig. 72.25: Two-dimensional echocardiography. Apical four-chamber view with anterior tilt showing double outlet right ventricle with nonrestrictive inlet ventricular septal defect (VSD; *). (AO: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

Fig. 72.26: Two-dimensional echocardiography in subcostal coronal view with anterior tilt in a case of double outlet left ventricle showing both the great arteries coming off from the left ventricle. (AO: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

A

B

Figs 72.27A and B: A case of ventricular septal defect and pulmonary atresia. Subcostal paracoronal view with color compare showing the atretic right ventricular outflow tract (arrow) and ventricular septal defect (*). (AO: Aorta; PA: Pulmonary artery.

1582


A

B

Figs 72.28A and B: Two-dimensional echocardiography of an infant with truncus arteriosus. (A) Subcostal coronal view with anterior tilt showing the single outflow-truncus arising from the ventricles; (B) Parasternal short-axis view showing the pulmonary arteries arising from the common trunk and bifurcating into left and right pulmonary arteries. (LPA: Left pulmonary artery; LV: Left ventricle; MPA: Main pulmonary artery; RPA: Right pulmonary artery; T: Truncus).

Connections and Spatial Relationship One has to differentiate between connections and spatial relationship of great vessels. Connections refer to the way the great arteries are aligned to the ventricular

mass, whereas spatial relationship refers to the way the great vessels are related to each other. The two features are independent of each other and should be separately defined echocardiographically.

PART 2: LEFT-TO-RIGHT SHUNTS: ATRIAL SEPTAL DEFECT, VENTRICULAR SEPTAL DEFECT, PATENT DUCTUS ARTERIOSUS, AND AORTOPULMONARY WINDOW In this section, echocardiographic findings of common shunt lesions are discussed. The addition of Doppler and color flow mapping also gives physiological information about flow and pressures and enables the pediatric cardiologist to refer patients for surgical treatment without cardiac catheterization, especially in neonates and infants. The commonly seen shunt lesions include ASD, VSD, patent ductus arteriosus (PDA), and aortopulmonary window (APW).

•

GENERAL FEATURES: SHUNT LESIONS There are a few salient features of all the shunt lesions. • The shunt would lead to volume overload of the chambers it feeds, generally described in relation to the tricuspid valve. If a shunt is proximal to the tricuspid valve, it would lead to volume overloading of the RA and RV, often referred to as pre-tricuspid shunt

•

(Fig. 72.29). If a lesion is beyond the tricuspid valve, it would lead to the volume overloading of the LA and LV, often referred to as post-tricuspid shunts (Fig. 72.30). The magnitude of the chamber enlargement depends upon the magnitude of the shunt (in the absence of anemia). Thus, significant RA and RV enlargement would be a feature of pre-tricuspid shunt, while a significant LA and LV enlargement would be a feature of post-tricuspid shunt (Fig. 72.30). The dimension of the chambers can be compared with standardized values to ascertain chamber dilation (e.g. by using z-scores). The pressure of the investigated chamber can rise on account of distal obstruction (obstruction of the outflow of the chamber) or it would be because of the transmitted pressure from the high pressure communicating chamber.


1583

Fig. 72.29: M-mode echocardiography of a pretricuspid shunt showing enlarged right ventricle and volume overloading of the right ventricle with flattened interventricular septal motion in an infant.

Fig. 72.30: M-mode echocardiography at the ventricular level (post-tricuspid shunt) showing dilated left ventricle (LV) with normal septal motion in a neonate.

– Increase in RV pressures may be because of infundibular or valvular pulmonary stenosis, obstruction in branch pulmonary arteries, or obstruction in pulmonary vascular bed (as in elevated pulmonary vascular resistance). – Increase in pressures in RV will also be seen in large VSD; similarly, a large PDA would lead to significant increase in PA pressures due to direct transmission of pressures. The magnitude of the gradient from a chamber outflow would also be dependent on the magnitude of shunt into the chamber (Fig. 72.29). – This may lead to exaggerated gradients even in hemodynamically insignificant lesions, namely exaggerated pulmonary gradients in pre-tricuspid shunts (like ASD), exaggerated mitral and aortic valve gradients in post-tricuspid shunts like VSD or PDA. The secondary manifestations of the shunt lesions may themselves lead to exaggerated secondary effects, for example, dilatation of LV leading to the mitral annular dilatation on account of post-tricuspid shunt may lead to mitral regurgitation and this may further lead to mitral annular dilatation and LV dilatation. Since a shunt lesion is a communication between two chambers, the gradient between the two chambers will be dependent on the size of the defect (Figs 72.31A and B). The size of the defect in two dimensions may be a useful guide in deciding the degree of shunt.

– The size of the VSD may be compared to the size of the aortic root for classifying the size of the VSD as large, moderate, or small. – The size of defects like ASD, VSD, would help in deciding the size of the device, which may be used to close these defects. Echocardiography should focus not only on the characteristics of the primary lesion, but also on the structures adjacent of the defect, for example, distances from the adjoining valves. – VSD—It is important to note the distances from the aortic valve and tricuspid valve when considering for device closure. – For ASD, the rims are seen not only for their adequacy to hold the device but also the adjoining structures which may be encroached whenever contemplating a device closure (Figs 72.32A to C). – For APW, the distance of the defect from coronaries and valves becomes important. – The post-tricuspid shunt is known to mask the manifestations of an anomalous LCA from pulmonary artery (ALCAPA), and thus, one should carefully look at the 2D anatomy and color flow mapping to define the origin of the coronary arteries whenever investigating a post tricuspid shunt lesion. Whenever investigating a shunt at multiple sites or an associated lesions, one must remember that the shunt flow may get exaggerated by the presence of distal obstruction and also by the associated shunt.

•

•

•

•

•

•

1584

A


B

Figs 72.31A and B: (A) Continuous wave Doppler signal of a patent ductus arteriosus, showing peak gradient of 89 mm Hg, systemic pressures were 100 mm Hg—estimated pulmonary artery (PA) pressures will be 11 mm Hg; (B) Shows the peak systolic gradient across the ventricular septal defect (VSD) of 98 mm Hg, systemic pressures were 120 mm Hg. By these observations, the predicted right ventricular (RV) systolic pressure would be 22 mm Hg.

A

B

C

Figs 72.32A to C: Two-dimensional transesophageal echocardiography. (A) Four-chamber view showing atrial and atrioventricular valve rims (arrows); (B) Basal short-axis view showing the atrial and aortic rims (arrows); (C) Modified basal long-axis view, showing the superior vena caval and inferior vena caval rims (arrows).


– The associated post-tricuspid shunt may lead to exaggerated manifestations of pre-tricuspid shunt lesions (e.g. ASD). Thus, RA and RV may be unduly dilated even in the presence of small ASD, with the associated presence of post-tricuspid shunt (VSD or PDA) or associated presence of mitral stenosis. – The associated aortic stenosis or coarctation of aorta (CoA) may exaggerate the shunt across the VSD. • The associated obstructive lesions distal to the shunt lesions may become masked and may manifest themselves only after the shunt lesion is closed. – Mitral stenosis may not manifest itself in the presence of ASD (although it may exaggerate the shunt flow across it). – The manifestations of significant mitral regurgitation may get unmasked after ASD closure. – High left ventricular end-diastolic pressure (LVEDP) may not only exaggerate ASD shunt, but also lead to pulmonary edema after ASD closure. – VSD or PDA may mask the gradients across aortic stenosis or CoA, which may manifest after the treatment of the underlying shunt lesion. • Certain systemic disorders and conditions may exaggerate or confound the echocardiographic features of a shunt lesion. – Anemia may exaggerate the gradients across any shunt lesion or across valves. Anemia may lead to LV dilatation, thus confounding the assessment of post-tricuspid shunt lesion. – Systemic hypertension may not only lead to exaggerated shunt gradients, but also result in secondary ventricular hypertrophy, thus leading to high LVEDPs and exaggerating ASD shunt. – Hyperdynamic states such as fever and thyroid disorders may exaggerate the shunt gradients. Thus, an assessment of a patient with a shunt lesion does not mean an isolated evaluation by echocardiography; it refers to complete clinical evaluation of the patient. Now we will discuss individually the assessment of shunt lesions seen commonly.

1585

•

Determining the volume overload, pulmonary arterial pressures, associated lesion, and complications. • Defining the lesions operability. • Deciding the relevant modality of treatment. The essential approach to any lesion should not be directed at the shunt lesion, rather it should be a standardized sequential analysis, as it is not the shunt lesion in isolation that exists and one needs to evaluate all the structural heart defects. A few salient features of the important shunt lesions—ASD, VSD, PDA, and APW—are discussed below.

ATRIAL SEPTAL DEFECTS Objectives (see Also Table 72.4) To diagnose ASD, assess the following: • Its anatomical site and size. • The direction and quantum of flow. • The degree of pulmonary arterial hypertension. • AV valve anomalies, pulmonary veins, and pulmonary valve stenosis.

Atrial Septal Defect Types1,2,14,15 Echocardiography plays a major role in the evaluation of ASD. Defects of atrial septum are classified as follows.

Patent Foramen Ovale Foramen ovale is a passage between septum secundum on right side and septum primum on left side. Its patency

Step-wise Approach (On Echocardiography) Step-wise approach (on echocardiography) for evaluation of any shunt lesion involves: • Determining the presence of shunt lesion (Fig. 72.33). • Defining its location and size of defect (Figs 72.32A to C).

Fig. 72.33: Two-dimensional transesophageal echocardiography. Basal long-axis view with color flow mapping showing left-to-right shunt flow. No additional defects are seen. (LA: Left atrium; RA: Right atrium).

1586


Table 72.4: Stepwise Evaluation for an Atrial Septal Defect

Initial indication is the volume overload of the chambers [right atrium (RA) and right ventricle (RV)] in 4C view Visualize the defect from subcostal view (sagittal and coronal views) Determine the site of defect: fossa ovalis or other Determine the direction of shunting Assess associated structures, particularly pulmonary veins and atrioventricular (AV) valves Assess pulmonary artery pressures: tricuspid regurgitation (TR) and pulmonary regurgitation (PR) gradients Determine suitability for device closure

These limbic bands separate the defect from atrial wall. These defects could be single, fenestrated mesh-like, or multiple.

Sinus Venosus Atrial Septal Defect (Figs 72.36A and B) The hallmark of all of these defects is that the border of the fossa ovalis should be intact, the defect is overlapped by either SVC in SVC type and by IVC in IVC type sinus venosus defect. There may be an associated anomalous drainage of pulmonary veins. Defects extending from the fossa ovalis superiorly or inferiorly should not be classified as a venosus defect. Fig. 72.34: Two-dimensional echocardiography. Subcostal bicaval view with color view mapping showing fossa ovalis atrial septal defect with left-to-right shunt. (SVC: Superior vena cava; RA: Right atrium; LA: Left atrium).

is a must for fetal survival and for normal growth of the fetal heart. After birth, the foramen ovale closes as left atrial pressure rises due to increased pulmonary venous return with fall in PVR. If pressure on either side of atria rises, stretching of flap of foramen ovale occurs and leads to shunting across foramen ovale. In most individuals, the foramen ovale is functionally closed shortly after birth; however, patency of a competent foramen ovale has been found in 25% of normal hearts on autopsy.

Fossa Ovalis Atrial Septal Defect (Figs 72.34 and 72.35) It is the commonest of the ASDs (69%) with varied sizes. This type of defect occupies the central part of atrial septum involving in part or whole flap valve of the foramen ovale. Septum ovale defects are bounded on either side by the limbic bands (superior and inferior limbic bands).

Coronary Sinus Atrial Septal Defect (Fig. 72.37) Coronary sinus ASD is a rare anomaly. It is located in the inferior most part of the atrial septum at the anticipated site of the coronary sinus ostium. The clue to the diagnosis of such a defect is the presence of a persistent left superior vena cava (LSVC) with evidence of RV volume overload.

Ostium Primum Atrial Septal Defect (Fig. 72.38) This defect is present in the lower most part of the atrial septum. This type of defect may be part of atrioventricular septal defect (AVSD) and may be characterized by the absence, in part or whole, of the atrioventricular septum.

Echocardiographic Imaging in Atrial Septal Defects Enlarged RA, RV, and paradoxical septal motion of interventricular septal motion are indirect evidence of


A

B

A

1587

Figs 72.35A and B: Two-dimensional echocardiography. Subcostal bicaval view with color comparison showing fossa ovalis atrial septal defect with adequate superior vena cava (SVC) rim (upper arrow) and deficient inferior vena cava (IVC) rim (lower arrows) and left-to-right shunt. (LA: Left atrium; RA: Right atrium; SVC: Superior vena cava).

B

Figs 72.36A and B: Two-dimensional echocardiography. Subcostal bicaval view with color comparison showing the superior vena cava (SVC) type of sinus venosus atrial septal defect. SVC is overriding the defect with partial anomalous pulmonary venous drainage of right upper pulmonary vein to SVC. (LA: Left atrium; RA: Right atrium; RUPV: Right upper pulmonary vein; SVC: Superior vena cava).

left-to-right shunt at atrial level. The best views to directly visualize the ASDs are subcostal coronal and sagittal views. ASD can be diagnosed by a drop out in the interatrial septum with flow across the defect on color flow mapping. When the defect is visualized, its relationship to the SVC and IVC should be evaluated. If the SVC forms the roof of the defect, it is SVC sinus venous type. If the IVC straddles

the defect, it is IVC sinus venosus type. The defects in the centre of the atrial septum involving the fossa ovalis area are fossa ovalis defects. The defect in the lower most part of the interatrial septum with atrioventricular valves attached at the same level are designated as ostium primum defects. The imaging should also be done from apical fourchamber and short-axis views. The four-chamber view will

1588


Fig. 72.37: Two-dimensional echocardiography. Subcostal coronal view with posterior tilt showing coronary sinus type of atrial septal defect (arrow). (LA: Left atrium; RA: Right atrium).

Fig. 72.38: Two-dimensional echocardiography. Apical fourchamber view showing a large ostium primum atrial septal defect (ASD) defect in lowermost part of the interatrial septum (arrow) with absence of offsetting of the atrioventricular (AV) valves (arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

also show the attachments of the AV valves. These may be at the same level in ostium primum defect. The color flow mapping across the defect will show the direction of flow and also presence or absence of any atrioventricular valve regurgitation. Doppler velocities across all valves should be taken, in particular the pulmonary valve to look for any pulmonary stenosis. The inflow velocities of the AV valves should be seen to rule out any mitral valve obstruction. The associated mitral obstruction may be missed unless specifically seen on 2D echocardiography, as there may not be a significant gradient across the mitral valve even with significant obstruction because of an associated ASD (true for all Lutembacher cases). All pulmonary veins should be specifically imaged to see if they are abnormally connected or not and to look for any pulmonary vein stenosis. The pulmonary veins are best seen in subcostal coronal and sagittal, apical four-chamber, PSAX, and suprasternal short-axis views.

than right atria. The second wave of left-to-right shunt occurs with atrial contraction. A small right-to-left shunt occurs during early systole when right atrial pressure exceeds left atrial pressure because of unequal activation time of the two atria. A second wave of right-to-left shunt occurs with rapid filling phase in early diastole. During that time, IVC flow tends to flow toward the LA. Respiration has some effect on direction of shunting; with inspiration, the left-to-right shunt decreases, while the reverse occurs during expiration. For the estimation of pulmonary arterial pressure, the peak gradient of tricuspid regurgitation gives the systolic pressure of the RV in absence of RV outflow obstruction. If pulmonary regurgitation is present, the pressure derived from the peak diastolic velocity will reflect the pulmonary arterial mean pressure. Doppler echocardiography accurately depicts the direction of shunting. • Pulsed Doppler: Pulsed Doppler shows the typical flow pattern as discussed earlier. • Color flow mapping (Figs 72.33 and 72.39): – With 2D imaging, color flow mapping clearly shows the net direction of flow. – M-mode—This is seldom used in daily practice but depicts best the direction of shunting during the various phases of a cardiac cycle.

Direction of Shunt14–16 With an isolated uncomplicated ASD, pressure between the two atria is similar with a variation up to 5 mm Hg, with cardiac cycle and phases of respiration. Dominant shunt occurs from left to right. Left-to-right shunt occurs mainly during mid to late systole as the “v”-wave of LA is larger


A

1589

B

Figs 72.39A and B: A case of total anomalous pulmonary venous drainage in a 2-year-old child. Two-dimensional echocardiography with color compare in subcostal sagittal view showing right-to-left shunt across atrial septal defect (arrow). (LA: Left atrium; RA: Right atrium).

Doppler and CFI should always be performed for the following reasons: • To confirm the presence of an echo dropout seen on 2D imaging. The characteristic pulse Doppler tracing and/or CFI confirms the echo dropout as a true defect. • Interrogation of the AV and semilunar valves for regurgitation and stenosis. In this regard, the presence of trivial to mild tricuspid or pulmonary regurgitation is a universal finding in large ASDs and is related to RV dilatation leading to tricuspid annulus and PA dilatation due to large pulmonary blood flow. Increased forward velocity across the pulmonary valves up to 3 to 4 m/s may be seen with large ASDs and does not always indicate pulmonary stenosis. The pulmonary valves in these cases are morphologically normal and there is no doming of the valve. • The tricuspid regurgitation velocity should always be obtained to predict the RV systolic pressure and hence indirectly the PA pressure. • Interrogation of the pulmonary veins should be done to rule out the association of pulmonary venous obstruction.

Objective Calculation of Qp/Qs Ratios Pulmonary and systemic flows can be calculated by the 2D and Doppler echocardiogram. The following formula is being used to calculate the flows: SV = SV : V : CSA : RR :

V × CSA × RR 1000 mL /1

stroke volume. mean velocity (velocity time integral). Cross-sectional area of flow (cm2). R-to-R interval (s/beat).

Cardiac output = stroke volume multiplied by heart rate and the (heart rate equals 60,000/RR interval), then the cardiac output will be V × CSA × 60s /min 1000 mL /1 To calculate pulmonary blood flow (Qp), PA mean velocity and diameter of pulmonary outflow can be measured from PLAX view of right ventricular outflow tract (RVOT) or PSAX view.

1590


To calculate the systemic blood flow (Qs), mean velocity across left ventricular outflow and the diameter of left ventricular outflow can be measured. To calculate the aortic mean velocity, apical five-camber view is used; the sample volume is kept just above the aortic valve leaflets. Other views that can be used to measure the aortic mean velocity are subcostal and suprasternal views. To measure the left ventricular outflow diameter, PLAX view is the best view. Other views that can be used to measure the left ventricular outflow diameter are subcostal and suprasternal. While taking the mean velocity, the Doppler beam should be positioned as parallel as possible to the flow, so that no correction for intercept angle needs to be made. To calculate the systemic and pulmonary blood flow, in place of left and RV outflow, we can use mitral and tricuspid mean velocity and annulus diameter in apical four-chamber view assuming no regurgitation in patients without shunt lesions. In patients with atrial shunt, the tricuspid flow will represent pulmonary blood flow and mitral flow will represent systemic flow. But in ventricular and aortopulmonary shunts, the mitral flow will represent the pulmonary blood flow + the systemic blood flow and aortic flow will represent the systemic flow. After calculating the systemic and pulmonary blood flow, left-to-right shunt can be calculated by subtracting systemic blood flow from pulmonary blood flow or the ratio of pulmonary and systemic blood flows, Qp/Qs can be calculated.

Limitations of Technique of Estimation of Degree of Left-to-Right Shunt Various Doppler methods to calculate Qp/Qs have been described, but there are several possible sources of error while Doppler is being used to calculate the flows; so we do not use this routinely. • Errors in the measurement of mean velocity due to: – Errors in determining the intercept angle. – The lack of a uniform velocity profile across the vessel lumen. – Variation caused by respiration or other physiological factors. During respiration, the variability in the velocity time integral at mitral and tricuspid valve are 14.5% and 13.2%, respectively. • Errors in measurement of cross-sectional area due to – Inaccurate gain settings. – Due to pressure, flow, and elasticity of vessel, the cross-sectional area of vessel changes throughout

the cardiac cycle and in various phases of respiration, particularly in the PA . – Measurement in the direction of lateral resolution.

Indication of Cardiac Catheterization Diagnostic cardiac catheterization in ASDs is indicated in those instances where correct evaluation of PA pressure is not possible by Doppler echocardiogram, pulmonary hypertension is suspected and information on PVR is required in decision making. This is because, although PA pressure may be reliably predicted by Doppler calculation, calculation of flow data is fallacious and can introduce error in the calculation of PVRs. In cases with elevated PVR, the reactivity of the pulmonary vascular bed can also be tested during cardiac catheterization.

Evaluation of Atrial Septum by Transesophageal Echocardiography1,2,16 In pediatric age group, transthoracic echocardiography using subcostal view provides a complete diagnosis and good assessment of ASD for interventional or surgical closure. In adolescents and adults, as subcostal windows do not provide adequate penetration, transesophageal echocardiography (TEE) is required for detailed profilation of the ASD. Views that are most useful for evaluation of ASD on TEE are: • Basal short-axis view. • Bicaval or basal long-axis view. • Four-chamber view.

Basal Short-Axis View This view can be obtained by keeping the endoscope in the middle part of esophagus. This view provides imaging of aortic valve and atrial septum. The aortic and atrial rims can be best seen in this view. The fossa ovalis defect is seen in middle part of atrial septum, sinus venosus defect SVC type is seen in the upper part of the septum adjacent to SVC, and the sinus venosus IVC type of ASD is seen in the lowermost part of septum adjacent to IVC.

Basal Long-Axis or Bicaval View This view can be obtained by keeping the endoscope at the same level and rotating the icon to 80° to 100°. This profiles the ASD in relation to superior and IVC, fossa ovalis defect is seen in middle part of septum. Sinus venosus defect


1591

Table 72.5: Stepwise Evaluation for Ventricular Septal Defect

Initial indication is the volume overload of the chambers [left atrium (LA) and left ventricle (LV)] Visualize the defect from all possible windows Determine the presence of additional defects (screening the septum—septal sweep in subcostal, apical four-chamber, parasternal short- and long-axis views in color and B-mode) Determine the direction of shunting through the defect Assess associated defects, particularly outflow obstructions and adjacent structures Assess pulmonary artery pressures: ventricular septal defect (VSD) gradients, tricuspid regurgitation (TR), and pulmonary regurgitation (PR) velocities Determine the volume overload of chambers (z-scores of LV, particularly in M-mode) Determine suitability for device closure or surgery

is seen in relation to SVC with SVC type of defect or in relation to IVC with IVC type of defect along with partial anomalous venous drainage of pulmonary vein. In case of fossa ovalis ASD, superior vena caval and inferior vena caval rims can be accurately assessed in this view.

view and apical four-chamber views. The aortic rim is best seen in transthoracic echocardiography PSAX view. The superior vena caval and inferior vena caval rims are best visualized on transthoracic echocardiography in subcostal sagittal (bicaval view).

VENTRICULAR SEPTAL DEFECT

Four-chamber View Four-chamber view can be obtained by keeping the endoscope at the lower part of esophagus. This view profiles the atrial septum with fossa ovalis defect in the middle of septum, atrial and AV valve rims, and volume overloaded RA and RV. By rotating the endoscope, we can see the attachment of right and left pulmonary veins draining into LA. In this view mitral valve morphology and mitral regurgitation can also be assessed.

Objectives (Table 72.5) • • • • •

Confirmation of VSD. Determination of the size and morphological location of VSDs. Ruling out associated lesions. Assessment of chamber size and wall thickness. Estimation of shunt size (pulmonary/systemic flow ratio). Estimation of RV and pulmonary arterial pressures.

Assessment of Fossa Ovalis Atrial Septal Defect for Percutaneous Device Closure

•

With the availability of various devices for the closure of ASD, the importance of detailed anatomy of the ASD including rims around the defect and the relationship with the surrounding structures has become of great importance. 2D echocardiography, both transthoracic and transesophageal, clearly show the anatomy and is used for selecting the cases for device closure of the ASD. During the procedure of device closure, TEE serves as the most important landmark for the proper placement of the “device.” We have proposed that for clarity, uniformity, and mutual communication, the rims should be designated according to the structure they are related, for example, superior vena caval, inferior vena caval, AV septal (rim at the crux), aortic, and atrial rims (rim of the superior wall of atrium near the right upper pulmonary vein). The AV septal and atrial rims are best visualized on transthoracic echocardiography in subcostal coronal

VSDs should be imaged from several planes. Artifactual dropouts may confuse the viewer using single plane imaging about the presence or absence of a VSD, particularly if it is small. The addition of color Doppler flow imaging is useful to reconfirm the presence of VSDs. CFI of VSDs has also radically improved the ability to detect unusually located and/or very small VSDs. Morphological location of VSD is described as viewed from the RV. VSDs can be classified into following types1,2,18–22 (Fig. 72.40): • Perimembranous VSD • Muscular VSD – Muscular inlet – Muscular outlet – Trabecular defect • Doubly committed VSD • Inlet VSD

Morphological Location17,18

1592


Perimembranous (Figs 72.41A and B) To identify a VSD as perimembranous, it is essential to demonstrate involvement of the membranous septal area. Cross-sectional echocardiography shows a discrete area of septal dropout in the area of the interventricular membranous septum adjacent to posterior semilunar

valve and tricuspid valve, with the membranous septum completely excavated away. However, perimembranous defects are not restricted to the membranous septum but always extend into one or more of the neighboring subunits of the muscular septum. Such defects are then subdivided into three distinct groups on the basis of the major extension of the defect. Perimembranous outlet defect: These defects excavate anteriorly from the area of interventricular membranous septum into the subarterial portion of the muscular outlet septum. They are called perimembranous subaortic defects. Such defects are not seen in a scan through the four-chamber plane and will only be seen when scanning the four-chamber plus aortic root plane, that is, fivechamber view or long-axis views. The defects are clearly roofed by the roof of the posterior great artery, with the trabecular septum and tricuspid valve forming their inferior rim. Large perimembranous outlet defects, which extend anteriorly below the whole great vessel root, are consistently visualized in the precordial long-axis plane, and are also visualized using serial short-axis scans.

Fig. 72.40: Schematic diagram of the interventricular septum with removed right ventricular (RV) cavity from the RV side. Various parts of the interventricular septum are shown: blue—muscular septum, dark yellow—perimembranous region, purple—the inlet septum, and light brown—outlet septum. (Ao: Aorta; IVC: Inferior vena cava; Mod.: Moderator band; PB: Parietal band; RA: Right atrium; SB: Septal band; SVC: Superior vena cava).

A

Perimembranous inlet defects: In these defects, the area of septal dropout associated with the defect extends posteriorly into the four-chamber plane as the defect excavates through the muscular inlet septum toward the crux of the heart. The roof of this posterior extension is formed by the atrioventricular junction tissue enclosed by the septal aspects of the mitral and tricuspid valve annuli. Anteriorly, this roof is formed by central fibrous body and AV muscular septum and posteriorly by the AV fibrous plane. Perimembranous inlet defects will be consistently

B

Figs 72.41A and B: Two-dimensional echocardiography. (A) Apical four-chamber view with anterior tilt showing the perimembranous ventricular septal defect (VSD) (arrow) getting restricted by septal leaflet of the tricuspid valve in two dimensions; (B) Color flow mapping of the same patient showing the turbulent jet of the restricted VSD with small left ventricle (LV)-to-right atrium (RA) shunt (arrow).


1593

visualized in a four-chamber plane roofed by AV valve septal leaflets, which insert into the central fibrous body at a common level. Scanning anteriorly to the junction of the four-chamber plane with the four chambers plus aortic root plane will demonstrate the involvement of the membranous septum by the defects. An isolated perimembranous inlet defect will not be visualized in any of the other standard echocardiographic planes recorded.

body or an AV or arterial valve ring. Since it is impossible to differentiate the subunits of the muscular septum accurately using cross-sectional echocardiography, correct classification of any muscular defect depends on accurate knowledge of where each subunit of the muscular septum is visualized within the various planes available to the echocardiographer. With this knowledge, it is possible to differentiate the muscular defects into three types.

Perimembranous trabecular defects: In the normal heart, the inferior border of the membranous septum merges imperceptibly into the trabecular septum. So it is not surprising that cross-sectional echocardiography can neither determine the precise junction of these two subunits, nor can it demonstrate involvement of the trabecular septum in a perimembranous defect. However, a correlation of echocardiography with morphological findings suggest that two echocardiographic features will indicate inferior extension of a perimembranous defect into the trabecular septum: (a) a broad blunt upper end of the interventricular septum forming floor of a perimembranous defect at the posterior aspect of a scan through the four-chamber plus aortic root plane, and (b) where any such defect is seen to extend inferiorly for more than half the aortic root diameter.

Muscular inlet defects: These defects lie within the boundaries of the smooth inlet septum and will be visualized by scanning through the four-chamber plane. They are not visualized in any other of the echocardiographic planes, and their characteristic feature, which allows differentiation from the perimembranous inlet defects, is that the upper muscular rim of the defect is separated from the AV junction by a muscle bar. Thus, in muscular inlet defects, the AV junction morphology is normal compared to the abnormal morphology in perimembranous inlet defects.

The morphological feature diagnostic of a muscular defect is that its rims are formed entirely by muscle and does not include the fibrous tissue of either the central fibrous

Muscular outlet defects: These defects have entirely muscular rims and are located in the smooth muscular outlet septum below the anterior portion of the aortic root and the subpulmonic infundibulum. This septal subunit is a small and extremely elusive structure. It is only profiled accurately in one echocardiographic view, subcostal RV outflow plane, but it can also be seen in PSAX view. In these planes, the defects are seen to be located mainly in the anterior muscular outlet-septum separated from the pulmonary valve by the muscular infundibulum. By definition, they never extend posteriorly to involve the membranous septum. Muscular outlet defects may occur in isolation or may present part of a complex lesion.

A

B

Muscular Ventricular Septal Defects (Figs 72.42 and 72.43)

Figs 72.42A and B: Two-dimensional echocardiography in subcostal coronal view (A) with anterior tilt and color compare; (B) Showing outlet muscular ventricular septal defect (VSD; arrow). (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

1594


A

B

Figs 72.43A and B: Two-dimensional echocardiography with color compare in parasternal long-axis view showing the apical muscular ventricular septal defect (VSD) with left-to-right shunt.

A

B

Figs 72.44A and B: Two-dimensional echocardiography with color compare in parasternal long-axis view showing the doubly committed ventricular septal defect (VSD) with left-to-right shunt.

Muscular trabecular defect: These defects are divided into: (a) Single trabecular defect—These are best visualized on short-axis scanning from the apex of the heart to the great artery roots or long-axis scanning of septum in different planes. Defect size is closely related to the ability of the cross-sectional system to identify the defect. (b) Multiple trabecular defects (Swiss cheese defects)—These defects may not be directly visualized by cross-sectional echocardiography. Multiple defects burrow through the septum obliquely and may not produce a complete echocardiographic window across the width of the trabecular septum, so that the septum may appear intact

on cross-sectional echocardiography. CFI is helpful also in defining multiple muscular defects.

Doubly Committed Subarterial Defects1,23,24 (Figs 72.44A and B) Doubly committed subarterial defect is roofed by conjoint aortic and pulmonary valve rings that appear to lie at the same level. In these defects, the ventricular septum will appear intact throughout the four-chamber plane. Doubly committed subarterial defects are seen from the four-chamber view with anterior tilt, paracoronal view,


parasternal long-axis, and PSAX views. Scanning anteriorly into the four chambers plus aortic root plane, the defects will be visualized below the aortic and pulmonary trunks, which take origin at the same level and are in a side-byside relationship. The conjoint arterial valves roof the defect, whose inferior margin is formed by the crest of the trabecular septum.

Fig. 72.45: Two-dimensional echocardiography in apical fourchamber view showing the large inlet ventricular septal defect (VSD) getting partially restricted by septal leaflet of tricuspid valve (arrow).

A

1595

Inlet Ventricular Septal Defect (Figs 72.45 and 72.46) The features of the inlet VSD are essentially the same as that of the muscular inlet VSD (described above) except for the absence of the muscular par below the inlet valves and there is continuity of both the inlet AV valves established by the presence of the VSD; therefore, off setting of the AV valve may not be present. Size of VSD: The size of any defect is important to comment but in practice, the judgment of size of defect is generally made on hemodynamic grounds (degree of left-to-right shunt, presence of volume overload, and PA pressure). According to some authors, a VSD size is defined in relation to aortic root size, a defect is defined as a small VSD if it is less than one third of aortic root diameter, one third to two thirds of aortic root diameter is considered as a moderate-sized defect, and defects that are more than two thirds of the aortic root size are defined as large VSDs. With isolated defects, when there is equalization of pressure between two ventricles in the absence of pulmonary stenosis, they are then termed large or nonrestrictive defects. Since right and LVs do not contract exactly simultaneously, there is always some inequality in the ventricular pressures. A restrictive defect is one in which RV and PA pressures are lower than LV with a pressure gradient of > 60 mm Hg (VSD peak velocity

B

Figs 72.46A and B: Two-dimensional echocardiography. (A) Subcostal coronal view with anterior tilt showing the perimembranous ventricular septal defect (VSD); (B) Parasternal long-axis view with posterior tilt toward the tricuspid valve and color compare showing the perimembranous VSD.

1596


> 4 m/s). Moderately restrictive VSDs have a pressure difference of 25 to 60 mm Hg (VSD peak velocity 2.5–4 m/s). In all patients, the aortic valve should be carefully profiled in relation to VSD, to rule out any prolapse of aortic cusps through the VSD making it appear artifactually small (Fig. 72.47). These patients will need surgery if one third or more of the aortic cusp is prolapsing through the VSD, or if it is associated with aortic regurgitation. There may be large malaligned VSDs (Figs 72.48A to C) that are associated with anterior or posterior malalignment of the outlet septum. These are generally very large and associated with either

Fig. 72.47: Two-dimensional echocardiography with parasternal long-axis view showing the doubly committed ventricular septal defect (VSD) getting partially restricted by the prolapse of the right coronary cusp (arrow). (LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

A

B

pulmonary stenosis, in case of anterior malalignment [as in tetralogy of Fallot (TOF)] or may be associated with posterior malalignment leading to subaortic obstruction. The latter may be associated with other left ventricular outflow tract (LVOT) obstructive lesions such as subaortic membrane, bicuspid aortic valve, or even CoA.

Doppler Evaluation of Ventricular Septal Defect Color Doppler Use of color Doppler has proved a valuable addition to the diagnosis of VSDs in several ways. • The location of VSDs especially smaller ones and multiple muscular ones can easily be determined using Doppler color flow mapping technique. • Size of VSD. • Determination of shunt direction across the VSD. • Color flow mapping is also useful for proper alignment of jet flow for Doppler interrogation. Color flow mapping has a major role in rapid detection and localization of VSDs (Fig. 72.49).25–28 Small ventricular septal defects, especially muscular, can be missed by 2D echocardiography. Color flow mapping is sensitive in detecting small and multiple VSDs. The sensitivity of color flow mapping is more with restrictive defects than nonrestrictive ones, probably because of early detection of a turbulent jet with a restrictive VSD. Color flow mapping has been used to define the direction of shunt across a VSD whether it is left-to-right

C

Figs 72.48A to C: Two-dimensional echocardiography. (A) Parasternal long-axis view showing perimembranous ventricular septal defect (VSD) with anterior malalignment of the septum (arrow); (B) Subcostal coronal view with anterior tilt showing the anterior malalignment of the septum (arrow); (C) Parasternal long-axis view showing perimembranous VSD with posterior malalignment of the septum (arrow).


1597

Continuous and Pulsed Wave Doppler Examination25–28 Pulsed and continuous wave Doppler examination is used to assess the direction of shunt across a VSD, pressure gradient across it (difference of LV–RV systolic pressure), RV pressure (by VSD gradient and peak gradient of tricuspid regurgitation jet), and diastolic function of both ventricles.

Direction of Shunt (Fig. 72.49)

Fig. 72.49: A 25-year-old man with Eisenmenger syndrome. Twodimensional echocardiography with parasternal long-axis view showing doubly committed ventricular septal defect with right-toleft shunt. (LV: Left ventricle; RV: Right ventricle).

or right-to-left, and whether it is laminar (high RV systolic pressure) or turbulent (low RV systolic pressure). With isolated restrictive VSD, the shunt is seen as a turbulent left-to-right jet during systole. With small or moderate size defects, because the LV diastolic pressure is higher than RV diastolic pressure, left-to-right shunt may persist during diastole also. With a nonrestrictive VSD with low PVR, left-to-right shunt occurs during systole with a small rightto-left shunt occurring during the isovolumic relaxation period. If in addition there is RV volume overload (associated significant tricuspid regurgitation, ASD, or anomalous pulmonary venous connection), right-to-left shunt occurs throughout diastole. In a child with isolated nonrestrictive VSD with high PVR, direction of flow can be bidirectional or dominantly right to left depending upon the severity of pulmonary vascular obstructive disease. With associated pulmonary stenosis, there may be isolated right-to-left shunt depending upon the severity of pulmonary stenosis. With severe RV outflow obstruction, a turbulent jet of right-to-left shunt may be seen in a small VSD due to suprasystemic RV systolic pressure. With the use of color flow mapping with careful interrogation, one should also identify if there is any LV to right atrial shunt as the high velocity of LV to right atrial jet can be misinterpreted as elevated RV pressure. This can happen particularly with VSDs, which are decreasing in size because of ingrowth of tissue from the septal leaflet of tricuspid valve.

With isolated uncomplicated nonrestrictive VSD, pressure between the two ventricles is similar. In patients with low PVR, dominant shunt occurs from left to right during systole, and with increase in LV, end-diastolic pressure left-to-right shunt will persist during diastole also. A typical “M”-shaped flow pattern is seen in patients with nonrestrictive VSD, explanation for which is: as LV contraction starts early and lasts longer than RV, so with onset of systole flow occur from left to right, with decrease in degree of shunt during midsystole as pressure between two ventricles equalize, and in later part of systole as RV relaxes, left-to-right shunt dominates. With restrictive VSD, left-to-right shunting occurs throughout systole. In some small muscular VSDs, left-to-right shunt occurs only during the early phase of systole, presumably because of closure of the defect in midsystole with ventricular contraction. Bidirectional or right-to-left shunting can occur with both restrictive and nonrestrictive VSDs as described earlier.

Pressure Gradient across Ventricular Septal Defect While taking continuous wave Doppler across a VSD, the cursor should be well aligned with the defect jet on color flow mapping. The velocity of the VSD shunt can be determined using the Bernoulli’s equation, p = 4V2, where p is the pressure difference and V is the maximum recorded velocity. This gives the difference between the left and RV systolic pressures. The left ventricular systolic pressure is derived from the systolic BP (provided there is no left ventricular out flow obstruction), which should be recorded at the time of Doppler study using appropriatesized BP cuffs. Right ventricular pressure = Systolic blood pressure–VSD jet peak gradient (4V2)

1598


Fig. 72.50: M-mode echocardiography in a case of ventricular septal defect showing a dilated left ventricle (LV) in a 2-year-old child.

This equation has been found to have good correlation with cardiac catheterization-derived RV systolic pressure. However, sometimes the jet velocity may not reflect the interventricular pressure gradient accurately because proper alignment of the Doppler beam with the jet is not possible, and that if the defect has some length to it, the viscous frictional forces make the application of the modified Bernoulli’s equation inappropriate. Also, because the dP/dt of the RV is lower than that of the LV, a falsely high jet velocity can be recorded in some cases with an anatomical large VSD. Determining the RV pressure from tricuspid insufficiency jet velocity (which may be found in some cases) is more accurate in such instances.

M-mode Echocardiography (Fig. 72.50) M-mode echocardiography is used to assess left atrial and left ventricular size, to provide an estimation of the degree of shunt across the VSD and to evaluate RV size and wall thickness, which will reflect elevated RV systolic pressure. For direction of shunt, color M-mode is rarely used in daily practice but depicts best the direction of shunting during the various phases of a cardiac cycle.

Interrogation of the Atrioventricular and Semilunar Valves for Regurgitation and Stenosis (Fig. 72.51) Tricuspid regurgitation velocity should always be obtained to predict the RV systolic pressure and hence indirectly the

Fig. 72.51: Two-dimensional echocardiography in apical fourchamber view with color compare showing the well-opened mitral valve (arrow) and turbulence across mitral valve on color flow mapping, because of increased flow across the mitral valve in a patient with nonrestricted perimembranous ventricular septal defect. (LA: Left atrium; LV: Left ventricle).

PA pressure if there is no pulmonary stenosis. Presence of pulmonary stenosis and aortic regurgitation should be evaluated. The velocities of flow across both AV valves and semilunar valves should be measured to rule out any associated abnormality.

Pulmonary Blood Flow to Systemic Blood Flow Ratio With regards to quantifying pulmonary and systemic shunt flow using Doppler echocardiography, several methods currently exist, although none is widely used due to variable results.

Assessment of Suitability for Device Closure Percutaneous closure for midmuscular VSDs and some perimembranous VSDs can be done. While assessing the child for device closure, the defect should be at least 5 mm away from AV valves and semilunar valves and other defects requiring cardiopulmonary bypass should not be present. The softer variety of Amptazer duct occluder II (ADO II) series can be used to close defects in the perimembranous region (particularly a defect with an aneurysm of the septal leaflet of the tricuspid valve) and muscular VSDs.


Utility of Transesophageal Echocardiography TEE has helped in better visualization of VSDs when the transthoracic window is poor, especially in adolescents and adults. Straddling and overriding of the AV defect can be better detected by TEE. TEE is extremely useful during percutaneous closure of these defects.

PATENT DUCTUS ARTERIOSUS Anatomy The ductus arteriosus is a remnant portion of the sixth aortic arch that connects the left PA with the descending portion of the aortic arch. The PA end of the PDA is usually immediately to the left of the PA bifurcation. The aortic connection is just distal to the origin of the left subclavian artery. The pressure differences across the PDA is estimated by the Doppler velocity, which will predict the pulmonary arterial pressures, systolic as well as diastolic, by its difference with the BP of the child. The flow across the PDA is estimated by the size of LA and LV. Spontaneous closure of the PDA usually begins at the pulmonary end within 24 hours of birth. Persistence of this fetal structure beyond 10 days of life in a term baby is considered abnormal. The ductus is funnelshaped in configuration in approximately two thirds of patients.27

Echocardiography1,2,29–31 Objectives (Table 72.6) • •

•

Demonstrate the presence of a duct. Detailed definition of ductus. – Size of the duct. – Type of duct. The hemodynamic significance of ductus. – Direction of shunt.

•

1599

– Pulmonary arterial pressure. – Quantification of shunt. Associated defects.

Echocardiographic Views The following echocardiographic views profile accurately the morphology of the duct. Ductal view (Fig. 72.52): The transducer is placed in the high parasternal window just beneath the left clavicle. After obtaining a short-axis cut of the great vessels visualizing the PA bifurcation, the transducer is rotated anticlockwise in gradual motion. At one point, the right PA goes away from the view and the duct with the adjacent descending aorta opens. This view in neonates and infants also visualizes the origin of the left subclavian artery. In patients with associated coarctation, the posterior shelf and coarctation can also be well visualized in this view. Suprasternal view: There are three views to visualize the duct from the suprasternal view. (1) Suprasternal long-axis view—This is the best view for visualizing the vertical duct arising from the undersurface of the transverse arch in patients with pulmonary atresia. The origin of such ducti is well seen, but the insertion point at the PA requires further anterior tilt. This is because of the tortuous nature of such ducti. In patients with discordant ventriculoarterial connection (e.g. transposition of the great vessels), the duct can be visualized well in its entire length in this view. (2) Suprasternal short-axis view—This is the classical short-axis arch view and can visualize those ducti which arise from the base of the left subclavian artery and descend straight down to insert into the left PA. If the aortic arch is right-sided and the patient has pulmonary stenosis physiology, the entire length of the duct can be seen in this view because unlike in patients with a vertical duct, it does not follow a tortuous course.

Table 72.6: Stepwise Evaluation for a Patent Ductus Arteriosus

Visualize the ductus ostium and aortic isthmus from the parasternal short-axis, high parasternal short-axis, and suprasternal views Determine the direction of shunt by color flow mapping and Doppler Take the peak velocity of the patent ductus arteriosus (PDA) signal, which will give the pressure difference between the aorta and pulmonary artery, and obtain the aortic, right ventricular outflow tract (RVOT), and pulmonary artery (PA) velocities Perform measurements of the left ventricle and left atrium as these will reflect the volume of the left-to-right shunt Specifically look for associated defects like coarctation of aorta (suprasternal view), subaortic membrane, bicuspid aortic valve, aortic interruption, and aortopulmonary window (communication between the ascending aorta and pulmonary artery)

1600


Fig. 72.52: Two-dimensional echocardiography in high parasternal view (ductal view) with color flow mapping showing patent ductus arteriosus (PDA; arrow) with left-to-right shunt. (Ao: Aorta; LPA: Left pulmonary artery; PDA: Patent ductus arteriosus).

The length of the duct needs to be measured to determine the choice of coil/device/stent. This view is particularly important for Amplatzer duct occluder II (ADO II) devices as it may give a fair estimate of the waist of the duct to decide for the device size. It is again best determined by the modified ductal view. In patients (older child, adolescent, and adults) where it is not possible to evaluate detailed anatomy of the duct because of inadequate windows, the size of the duct can be determined by the narrowest width of the color flow across the duct. This, however, always overestimates the ductal size and gives only a rough estimate. In all cases where nonsurgical intervention is planned, these measurements performed by echocardiography will need to be confirmed by the gold standard, that is, angiography.

Duct Morphology Usual Ductus

(3) Modified suprasternal long-axis view (Ductal view)— This is a less well-described view to visualize the usual duct. It has the advantage of visualizing the duct in its entire length and most closely mimics the lateral angiogram performed during cardiac catheterization. From the usual suprasternal long-axis view, the transducer is rotated anticlockwise. A slight anterior tilt then shows the duct from its ampullary part to its insertion and accurate measurements of the ductus size can be made.

Characteristics of the Ductus Size of Duct Because of frequent interventions being performed on the duct (closure/stenting), it has become important to make various measurements of the duct by echocardiography. These include the following.

Size of the Narrowest Part of the Duct This should be done at the narrowest point (as this site would be hemodynamically most restrictive). In the majority of cases, this would be at the site of PA insertion. In the usual duct, this can be accurately measured in the ductal view or the modified arch view.

Size of the Ampulla of Duct To the interventionist, the size of the ampulla is important to determine the possibilities of coil placement. The ampulla can be best measured in the modified ductal view.

The usual ductus arises from the descending aorta just below the origin of the third branch of the aortic arch (left subclavian artery with left aortic arch) and inserts into the PA immediately to the left of PA bifurcation. This type of ductus is best defined from the ductal and modified suprasternal views. It narrows at the PA end and is of “funnel shape,” has a straighter course, and the Doppler signals can be very well aligned from the ductal view. For catheter interventions like ductal coiling/device closure or ductal stenting, these ducti are easy to cannulate by the femoral artery route. Other uncommon configurations of ductus include the following: • Short duct with narrow aortic end • Tubular connection with no narrowing • Tubular connection with multiple narrowings • Calcified PDA • Aneurysm of the aortic end of the PDA. Aneurysm of ductus arteriosus at the aortic end is a rare complication in adult patients with ductus arteriosus and can be profiled from the ductal view.

Vertical Duct A vertical duct arises from the undersurface of the aortic arch, has a tortuous course, and is commonly seen in patients with VSD and pulmonary atresia because of in utero flow from the aorta to the pulmonary arteries. The best view to define a vertical duct is suprasternal long-axis view. This view shows the duct arising from the undersurface of arch and having a “S” curve. Because


of the double curve, it is not possible to visualize the aortic and pulmonary ends in the same view. Anterior angulation of the transducer will show the PA insertion of the duct. These ducti are difficult to cannulate from the femoral artery route and may have to be accessed from the ascending aorta or from the upper limb arteries.

1601

appears as predominantly red flow with minimal aliasing. In patients with severe pulmonary arterial hypertension, a bidirectional shunt is visualized on CFI. With suprasystemic PA pressure as in duct-dependent systemic blood flow, a turbulent high velocity right-to-left flow in systole and diastole in the descending aorta is observed. This can mimic coarctation of the aorta.

Subclavian Origin Subclavian origin of ductus occurs with duct-dependent pulmonary blood flow with right aortic arch. The suprasternal view defines best this ductus. It has a straighter course; hence the Doppler alignment is good. For catheter intervention, it is easy to cannulate this type of ductus arteriosus from the femoral arterial route.

Hemodynamic Significance Hemodynamic significance of ductus arteriosus can be assessed by evidence of volume overload of LA and LV, direction of shunt, and pulmonary arterial pressure.

Chamber Dimensions Left atrial enlargement signifies increased pulmonary venous return because of left-to-right ductal shunting. The ratio of the LA to aorta (Ao) is measured at the level of the aortic valve (the LA: Ao ratio) by M-mode echocardiography in PLAX view. The aortic root does not enlarge significantly with even an extremely large PDA. In general, LA: Ao ratio > 1.3:1 indicates a significant shunt. The LV will enlarge as cardiac output increases with increased pulmonary venous return. The best method to determine the presence of volume overload of the LV is M-mode measurement of left ventricular diastolic dimension and comparing it with normal values for the patient’s age and weight.

Direction of Shunt and Pulmonary Arterial Pressure31–33 Color Doppler Imaging of Duct Color flow mapping increases the sensitivity of detection of a ductus. This includes a tiny duct, which may not be seen on 2D imaging and adolescent or adult patients where absence of good windows (especially ductal view) prevents visualization of the duct on 2D imaging. On color flow mapping, a small duct with normal PA pressure is displayed as a mosaic flow from descending aorta to PA. With a large duct, and low PVR, the duct jet generally

Continuous Wave Doppler Examination of Ductus Arteriosus With the use of continuous wave Doppler, the direction of shunt in relation to cardiac cycle and pulmonary arterial pressure (systolic BP minus peak pressure gradient across duct = systolic pulmonary arterial pressure) can be assessed. Systemic diastolic pressure minus the pressure derived from the diastolic velocity of PDA signal gives the diastolic pressure in the PA. With an isolated left-to-right shunt, and a small to moderate-sized duct normal or mildly elevated PA pressures are seen. Doppler examination of such a duct shows continuous flow toward the transducer with the peak in late systole. A large duct with pulmonary arterial hypertension will show bidirectional shunting on Doppler imaging of the duct, right to left in systole and left to right in diastole. With increasing PVR and no step-up in oxygen saturation in the PA, the peak of rightto-left shunt appears early in systole. With further rise in PVR, right-to-left shunt begins in systole extending to diastole. With duct-dependent systemic circulation and severe pulmonary arterial hypertension, only right-to-left shunting across the duct is visualized.

Evidence of Aortic Runoff (Figs 72.53A and B) Presence of aortic run off in a patient with a ductus is indicative of low pulmonary diastolic pressure and blood flow from aorta to PA occurs in diastole, which can be detected by M-mode color flow mapping. Thus, color flow mapping shows flow reversal in the descending aorta in diastole up to the level of the duct. On continuous wave Doppler examination of the descending aorta from the suprasternal long-axis view below the ductus, forward flow signals in systole (below the baseline) and reverse signals in diastole (above the baseline) are noted. The reverse signals indicate flow from descending aorta to PA. With the Doppler sample volume placed above the level of the duct, flow will be in a forward direction in both systole and diastole.

1602


A

B

Figs 72.53A and B: (A) Two-dimensional echocardiography in suprasternal view showing diastolic flow reversal in the arch of aorta; (B) Same view with cursor across the flow on M-mode showing pan-diastolic flow reversal. (D. Ao: Descending aorta; TA: Transverse arch).

Limitations of Echocardiographic Imaging of the Duct There are several limitations of profilation of a duct by 2D imaging. • Limited acoustic windows: The duct is profiled in the direction of lateral resolution of the transducer, hence it is difficult to visualize with certainty a very small duct in small babies. A high frequency probe with an excellent lateral resolution is helpful. • If the duct is long and tortuous, it may be difficult to profile the whole length of the duct. • Poor acoustic windows in adolescent and adult patients, deformity, hyperinflated lungs, very obese children.

Limitations in Hemodynamics The long length of a PDA results in underestimation of pressure gradients across it.

AORTOPULMONARY WINDOW (FIGS 72.54A AND B) Aortopulmonary window (APW) or aortopulmonary septal defect accounts for 0.2 to 0.6% of patients with congenital heart defects.34 Nearly half of all patients have associated cardiac lesions, including aortic origin of the right PA,35–39

type A interruption of the aortic arch,36,39–41 TOF,39–42 and anomalous origin of the right or LCA from the PA and right aortic arch.39,43,44 More rarely, it is associated with VSD,44–46 pulmonary39 or aortic atresia, d-transposition,47 and tricuspid atresia.48

Types APW is classified into three types:37 Type I: Defect between semilunar valves and PA bifurcation. Type II: Distal type defect involving origin of right PA. Type III: Large defect involving both type I and type II. Echocardiography: Objectives are: • Diagnosis • Type of APW • Associated heart defects • Operability 2D echocardiography usually can accurately diagnose the aortopulmonary septal defect. Views most useful for profiling an APW are subcostal coronal view, fivechamber view, PSAX plane at the level of great vessels, and the suprasternal views. In all these views, the wall separating the aorta and PA is aligned in the direction of lateral resolution, so great care is needed to differentiate a true defect from an artifactual dropout. A “T” artifact at the edges of the defect will distinguish it from a normal dropout and CFI will confirm the defect.


A

1603

B

Figs 72.54A and B: Two-dimensional echocardiography with color comparison in parasternal short-axis view showing a large aortopulmonary window (arrow). (Ao: Aorta; PA: Pulmonary artery).

A

B

Figs 72.55A and B: Two-dimensional echocardiography with color mapping showing the Gerbode defect (arrow) with left-to-right shunt. (Ao: Aorta; RA: Right artium; LV: Left ventricle).

Color Flow Mapping Color flow mapping is used to demonstrate flow through the defect. With large defects, which usually is the case, the flow appears laminar, low velocity, and bidirectional across the defect, and with smaller defects, a continuous high velocity left-to-right jet is usually present. With low PVR, evidence of aortic runoff can be detected in both ascending and descending aorta in contrast to PDA in which normal aortic flow is seen in ascending aorta and the arch. The operability will depend on the degree of left-to-right shunt as assessed on color flow mapping, and the presence of left atrial and left ventricular enlargement.

GERBODE DEFECT (FIGS 72.55 AND 72.56) In this entity, the shunt occurs from LV to RA through a defect in the membranous ventricular septum and essentially leading to volume overload of the RA and the RV. In these cases, RA dimensions and features of right atrial and ventricular volume overload need to be evaluated. The features are essentially same as ASD. The point to remember is that the pressure difference across the tricuspid valve taken in these circumstances may be fallacious as one may mistake the high velocity LV to RA jet for the tricuspid regurgitation velocity resulting in an erroneous diagnosis of severe PA hypertension.

1604


A

B

Figs 72.56A and B: Two-dimensional echocardiography with color comparison in parasternal short-axis view showing Gerbode defect (arrow) with left-to-right shunt (arrow). (Ao: Aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle).

PART 3: ATRIOVENTRICULAR SEPTAL DEFECTS ATRIOVENTRICULAR SEPTAL DEFECTS Atrioventricular septal defects (AVSDs) account for 4 to 5% of CHD and an estimated occurrence of 0.19 in 1,000 live births.49,50 About 40 to 45% of children with Down syndrome have CHD, and among these, approximately 40% have an AVSD, usually the complete form.49 Complete AVSD also occurs in patients with heterotaxy syndromes (more common with asplenia than with polysplenia). Common atrium has been associated with Ellis–van Creveld Syndrome. The assessment of the AV junction is readily achieved by 2D echocardiography and since AVSDs are primarily an abnormality of this region, delineation of detailed morphology is possible by this technique. Color flow Doppler interrogation complements by demonstrating the sites of intracardiac shunting and AV regurgitation, as well as defining any obstruction in the LVOT if present. Pulsed and continuous wave Doppler are used to assess PA pressure and severity of LVOT obstruction.51–58 The following basic views can define these anatomical features (Table 72.7). Subcostal coronal view shows the common AV junction, loss of offsetting of AV valves, scooped out inlet septum, and inferior bridging leaflet of AV valve (Fig. 72.57). Subcostal sagittal view shows the common AV junction, in addition to both superior and inferior bridging leaflets and anterior unwedged position of aorta. Subcostal

long-axis view of LVOT defines the “goose neck” deformity of LVOT (long LVOT with anterior position of the aorta; Fig. 72.60). Apical four-chamber view will display the inlet VSD with loss of offsetting (Fig. 72.59). PSAX view shows the trileaflet left AV valve, presence of cleft; presence of common AV junction, and abnormal position of the papillary muscles in the LV. PLAX view shows discrepancy in the left ventricular inflow and outflow measurements and presence of LVOT obstruction (Fig. 72.58).

Types Of Atrioventricular Septal Defect Partial Atrioventricular Septal Defect (Fig. 72.61A)51–56,59,60 Subcostal coronal and sagittal views supplemented with apical four-chamber, PLAX and short-axis views can define the anatomy with great accuracy. In addition, AV valves need to be profiled in subcostal en face view by rotating the transducer 30 to 45° clockwise from subcostal four-chamber view. From this view, with tilting the plane from anterior to posterior, all five leaflets, separate AV valve orifices, attachment of anterosuperior bridging leaflet to anterior muscular septum, and posteroinferior septum to inlet septum can be defined. The opening of AV valves is seen as two separate openings created by the


1605

Table 72.7: Common Features on Echocardiography in a Case of Atrioventricular Septal Defect

Loss of offsetting of atrioventricular valves Deficiency of inlet portion of ventricular septum Presence of common atrioventricular valve junction Abnormal morphology of atrioventricular valve leaflets Abnormal position of papillary muscles of left ventricle Longer left ventricular outflow, and anterior unwedged position of aorta

Fig. 72.57: Two-dimensional echocardiography. Subcostal paracoronal view with anterior tilt showing the components of the common atrioventricular (AV) valve. (Ao: Aorta; IBL: Inferior bridging leaflet; LV: Left ventricle; RV: Right ventricle; SBL: Superior bridging leaflet).

Fig. 72.58: Two-dimensional echocardiography. Parasternal long-axis view from an infant with complete atrioventricular septal defect showing discrepancy in left ventricular inflow (line-a) and outflow (line-b) measurements. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

Fig. 72.59: Two-dimensional echocardiography in apical fourchamber view showing large inlet ventricular septal defect (VSD; arrow) in a case of atrioventricular septal defect. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 72.60: Subcostal apical four-chamber view with anterior tilt in diastole showing “goose neck deformity” of left ventricular outflow tract, that is, left ventricular outflow tract is elongated with anterior unwedged position of aorta (arrow). (Ao: Aorta; LV: Left ventricle; RV: Right ventricle).

1606


A

B

Figs 72.61A and B: Two-dimensional echocardiography. (A) Apical four-chamber view showing a large ostium primum atrial septal defect (ASD; arrow), no ventricular septal defect (VSD), lack of offsetting of the atrioventricular (AV) valves (arrow); (B) Apical fourchamber view showing a large ostium primum ASD and a large inlet VSD. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

presence of a bridging tongue of tissue. The characteristic features of partial AVSD are two separate AV orifices within the common AV junction, abnormal valve leaflets with or without cleft, and usually presence of ASD between lower part of atrial septum and the crest of the ventricular septum. Leaflets are attached to the crest of ventricular septum, so there will be loss of offsetting and usually there is no VSD or it is restrictive, although this is not a universal finding. Rarely, only inlet VSD and intact interatrial septum is present when the bridging leaflets are attached to the lower part of the interatrial septum. VSD can be profiled from subcostal coronal and sagittal, apical four-chamber, and PLAX with posterior tilt and short-axis views. Here the trileaflet left AV valve guarding the left component of the common AV junction, seen in PSAX and subcostal en face views, will be the hallmark feature to differentiate it from an isolated inlet muscular VSD. Rarely, a left AV valve with three leaflets may be the only manifestation of an AVSD with intact atrial and ventricular septum. There may be a cleft of only left or right AV valve (more commonly of left side). The cleft can be profiled in the subcostal en face view and PLAX and PSAX views. In PSAX view, the cleft (zone of

apposition between superior and inferior bridging leaflets) is seen toward the ventricular septum to differentiate this anomaly from an isolated cleft of mitral valve, where the cleft will be oriented toward the LVOT (Fig. 72.66). Also, other features of AVSD such as a longer LVOT, unwedged and anterior position of aorta as described earlier will be present. Less common variant is common atrium (virtual absence of atrial septum), usually found in the setting of left or right isomerism. Associated anomaly of AV valves such as a dual orifice AV valve with or without stenosis and Ebstein’s anomaly of right AV valve can sometimes be present and should be looked for on 2D echocardiography (Table 72.8).

Complete Atrioventricular Septal Defect (Atrioventricular Septal Defect with Common Valvular Orifice (Fig. 72.61B)53–56,61–63 The typical echocardiographic features of complete AVSD seen in subcostal coronal and sagittal, and apical


1607

Table 72.8: While Evaluating a Patient with Atrioventricular Septal Defect, the Following Needs to be Addressed

Type of defect—partial or complete atrioventricular septal defect Extent of atrial shunting Extent of ventricular shunting Presence and degree of atrioventricular valve regurgitation Commitment of atrioventricular valves to respective ventricles, is there balanced atrioventricular connection or unbalanced atrioventricular connection, degree of ventricular hypoplasia if present Presence of straddling Potential for left or right ventricular outflow obstruction Pulmonary artery pressures Associated lesions

four-chamber views are ostium primum ASD, common AV valve guarding the common junction, and an inlet interventricular communication of variable size. The VSD can be small or large depending upon the attachment of the bridging leaflets. As described earlier, the inferior bridging leaflet is seen best in subcostal coronal view, and it may be firmly attached by a midline raphae to the septum; as a result, there will be no interventricular communication close to crux. The superior bridging leaflet is seen in apical four-chamber view with anterior tilt and most of the variations in ventricular component of shunting are seen beneath the superior bridging leaflet. The subcostal en face view shows both superior and inferior bridging leaflets. When the superior bridging leaflet is attached firmly to the septal crest, there is no defect beneath it; more commonly, this leaflet is attached to a normally positioned medial papillary muscle and is attached by multiple cords to the crest of the septum. There are then multiple interventricular communications through the intercordal spaces, and the flow can be recognized on color flow mapping. This type of defect is called as Rastelli type “A” under Rastelli classification. In the so-called Rastelli type B, the RV medial papillary muscle is positioned in midseptal position, the degree of bridging is greater, and the bridging leaflet is less well attached to the ventricular septal crest, and becomes free-floating. When the papillary muscle is located still further in the RV, a so-called Rastelli type C defect is produced. In this situation, almost always a large VSD is present and is particularly frequent in Down’s syndrome. Rarely with complete AVSD, there will be absence of any interatrial shunt when the superior bridging leaflet is attached to the lower end of atrial septum, and absence of VSD when it is firmly attached to the ventricular septum as described with a partial AVSD.

Commitment of atrioventricular valve to ventricle and relationship of atrioventricular valve leaflets to the septal structure—balanced or unbalanced atrioventricular septal defect: Apical four-chamber, subcostal coronal, and subcostal en face views are required to profile commitment of AV valves to respective ventricles, and to look for presence of overriding. These views allow simultaneous visualization of all four chambers, AV valves, and atrial and ventricular septa. If the AV junction is shared equally, then there is a balanced AV connection. When there is overriding of AV valve to one of the ventricles and malalignment between atrial and ventricular septum, then the condition is termed as unbalanced AV connection leading to hypoplasia of left or RV depending upon the degree of overriding (Figs 72.62 and 72.63). One of the AV valves can be atretic, causing hypoplasia of the respective ventricle. Abnormal relation between atria and ventricles can also occur when the common AV junction is not equally shared between both the ventricles but is committed exclusively to one or the other atrium. This condition is termed as double outlet atrium or uniatrial biventricular AV connection and can be defined in subcostal and apical four-chamber views.64–66 Straddling of AV valves is also an issue that needs to be defined. Straddling of left AV valve is profiled in PLAX view while for right AV valve, the four-chamber view and subcostal en face view are required to profile the chordal attachments. Color flow mapping is required to define presence and direction of shunting across interatrial or interventricular septum, presence of AV valve regurgitation or stenosis, and presence of left or RVOT obstruction. Direction of shunt across ASD or VSD can be profiled from views used to define the defects. Subcostal, coronal, apical four-chamber, and PSAX views are required to look for presence of AV valve

1608

A


B

Figs 72.62A and B: Two-dimensional echocardiography. Apical four-chamber view showing unbalanced atrioventricular canal defect with left ventricle (LV) dominance (A) and right ventricle (RV) dominance (B). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

regurgitation, presence of LV–right atrial shunt, or RV— left atrial shunt. RV—left atrial shunt could be a cause of cyanosis in a child with partial AV canal defect with normal PA pressure. The quantitative assessment of valvular stenosis is not accurate by Doppler echocardiography when there is a large ASD. So it is important to evaluate valve anatomy by 2D echocardiography and look especially for dysplasia, tethering of leaflets, and valve orifice. In such cases, valve stenosis may manifest after closure of the ASD if not addressed at surgery. The outflow tract of both LV and RV should be assessed, as subvalvular obstruction of any of the outflows can occur. Left ventricular outflow tract obstruction (Table 72.9):62–68 LVOT is longer and narrower than normal in AVSD, although in most cases there is no overt stenosis. Any factor that causes further narrowing of LVOT causes LVOT obstruction. Causes of LVOT obstruction are highlighted in Table 72.9. Right ventricular outflow tract obstruction: Pulmonary stenosis can occur at subvalvular (malalignment of outlet

septum, infundibular hypertrophy), valvular, or supravalvular level. Complex atrioventricular septal defect: A complex AVSD can be defined as an AVSD morphology that precludes two-ventricle correction.66-69 The following conditions can be the cause of such a situation: • The most frequent is the association of AVSD with heterotaxy/isomerism. Anomalous systemic/pulmonary venous connection and hypoplasia of ventricles frequently precludes biventricular correction. • Abnormalities of ventricular arterial connections. • AVSD can be associated with DORV, making it difficult or impossible to route the LV to aorta as the VSD, thus precluding a two-ventricle repair. • Right/left ventricular dominant AVSD. Because of extreme straddling/overriding of the common AV valves across the VSD, one of the ventricles may be hypoplastic. This will prevent two-ventricle repair. In most cases, quantification of hypoplasia is subjective, based on echocardiography (Figs 72.62A and B).


1609

Table 72.9: Left Ventricular Outflow Tract Obstruction in Atrioventricular Septal Defect

Tight adherence of superior bridging leaflet to septal crest causing left ventricular outflow tract to be longer and narrower. Left ventricular outflow tract obstruction is more common in partial atrioventricular septal defect and with primum ASD Discrete subaortic membrane Ventricular septal hypertrophy Abnormal chordal attachment of superior bridging leaflet Prominent anterolateral muscle bundle Left ventricular outflow tract can be profiled from subcostal coronal view with anterior tilt, subcostal sagittal view, and parasternal long-axis view. Color flow mapping shows turbulence beginning in subaortic area Careful Doppler interrogation shows site of obstruction and severity of obstruction of left ventricle outflow tract

A

B

C

D

Figs 72.63A to D: (A) Subcostal en face view profiling the common atrioventricular (AV) valve completely; (B) Tracing the common AV valve orifice during end diastole, averaged over three cardiac cycles (area B); (C) This circumference is then divided by a line drawn over the interventricular septum from the tip of the infundibular septum to the crest of the muscular septum, thus dividing the AV valve into left and right components (D) Take the area of the left component. For a balanced atrioventricular septal defect, AVVI (“A” area/“B” area in figure) should be > 0.67.

1610


The area of the common AV valve and left component can be measured and the ratio calculated as shown in Figs 72.63 A to D to quantitate the hypoplasia. Associated defects: TOF and DORV with malposed great vessels are frequently associated with complete AVSD, especially in the setting of isomerism.69 With unbalanced AV connection leading to hypoplastic LV, aortic arch should be carefully profiled in the suprasternal long-axis view to rule out arch anomalies like CoA and arch interruption. With hypoplastic RV, pulmonary stenosis and pulmonary atresia may be associated and need to be profiled carefully.

Hemodynamic Assessment of Atrioventricular Septal Defect Without Pulmonary Stenosis Partial atrioventricular septal defect: These defects behave like an ASD. In the absence of significant AV valve regurgitation and normal PA pressure, the lesion is well tolerated and patients may present late like fossa ovalis ASDs. Significant AV valve regurgitation, however, may cause early congestive heart failure. Accurate assessment of PA pressure and AV valve regurgitation is critical in decision-making for timing of surgery. Doppler assessment of PA pressure is usually performed by assessing tricuspid regurgitation velocity. Care should be taken in not confusing LV–right atrial shunt for tricuspid regurgitation as the former (LV–right atrial shunt) will invariably produce high velocity signals which will not be reflecting pulmonary arterial pressures.

Complete atrioventricular septal defect: This is associated with large VSD and pulmonary arterial hypertension. Thus, congestive heart failure develops in the first few months of life. Also, rapid progression (6 months of life) of pulmonary vascular disease occurs in this condition. Thus, there is an urgent need to correct these lesions early in life. If correction is performed at the appropriate age, then echocardiography alone is enough for assessment of this lesion as the morphology is well delineated by this technique and there is no need for invasive determination of PA pressure and vascular resistance. Late presentation, however, may need more detailed evaluation with cardiac catheterization.

With Pulmonary Stenosis Patients with pulmonary stenosis present as TOF. However, the morphology is much more complicated. The VSD, which is predominantly of the inlet type, also extends into the outlet septum. Anterior malalignment of the outlet septum causes RV outflow obstruction and other morphological abnormalities associated with TOF.

Mechanism of Atrioventricular Valve Regurgitation In the majority of cases, AV valve regurgitation occurs through the cleft in the left AV valve. This is well-appreciated in the PSAX views and subcostal paracoronal (en face) view. Regurgitation can also occur through the commissures of the left AV valve or through the right AV valve.

PART 4: CONGENITAL LEFT VENTRICULAR AND RIGHT VENTRICULAR INFLOW ANOMALIES CONGENITAL ANOMALIES OF MITRAL VALVE (TABLE 72.10)70 Mitral stenosis or mitral regurgitation forms the predominant manifestation of mitral valve anomalies. Other associated cardiac anomalies are present in 90% of them. Echocardiography can assess the degree of severity of the lesion and define the varied anatomy preoperatively for planning the surgery. It is useful intraoperatively to guide the surgery and postoperatively to assess the outcome.70–74

Echocardiographic Views to Define Mitral Valve Lesions Mitral valve is best visualized in parasternal long-axis, apical four-chamber and two-chamber views, and in PSAX view. Addition of color Doppler further helps to diagnose the abnormalities. PLAX view shows the motion of mitral valve leaflets and any evidence of doming or prolapse can be noted. The chordal length, chordal thickening, and chordal insertion are also well seen in this view. Additional


1611

Table 72.10: Common Mitral Valve Abnormalities

Supramitral membrane or ring Hypoplasia of the mitral apparatus Dysplasia of the mitral valve Parachute mitral valve Cleft mitral leaflet (anterior or posterior) Abnormal mitral arcade Double orifice mitral valve Accessory mitral valve tissue/orifice Ebstein’s anomaly of the mitral valve Mitral valve prolapse Mitral regurgitation secondary to other causes, some of which are congenital •

Infective – Myocarditis –

Kawasaki disease

– Infective endocarditis •

Rheumatic heart disease

•

Papillary muscle dysfunction

– Mitral regurgitation and mitral stenosis – Ischemia – Anomalous origin of the left coronary artery from the pulmonary artery • Cardiomyopathy – Dilated cardiomyopathy – Hypertrophic cardiomyopathy –

Storage disease/infiltration

–

Hurler disease

– Amyloidosis •

Connective tissue disease – Marfan's syndrome

Fig. 72.64: Two-dimensional echocardiography in subcostal short-axis view with color flow mapping from a child with partial atrioventricular septal defect showing left atrioventricular valve regurgitation through the cleft (arrow). (LV: Left ventricle; RV: Right ventricle).

with stenosis, to see the level of stenosis. Doppler is also useful in estimating gradients and valve area. Gradients by Doppler may be underestimated due to associated interatrial defect or due to poor alignment secondary to multiple levels of obstruction to left ventricular inflow. Pressure half-time method is often not reliable in this setting. Planimetry of the mitral valve orifice in PSAX view may be the best method for assessment of mitral valve area. The normal mitral valve area is 2.4 to 3.6 cm2/m2. In mild mitral stenosis, the valve area is reduced to 1.2 to 2.4 cm2/m2; in moderate mitral stenosis, mitral valve area is 0.6 to 1.2 cm2/m2; and in severe mitral stenosis, the valve area is < 0.6 cm2/m2.

– Ehlers–Danlos syndrome, etc.

abnormalities of LVOT like subaortic membrane, tubular narrowing, and so on can be assessed. Apical four-chamber view shows ventricular inflow region and any obstructive membrane or ring in the atrium, like a supramitral ring. The valve annuli can be measured. Apical four-chamber view is good for showing dilatation of atria, which may occur secondary to atrioventricular valve stenosis and/or regurgitation. PSAX view shows orientation of commissures, chordae, and papillary muscles including the number of papillary muscles. Cleft mitral valve (Fig. 72.64) and double orifice mitral valve are also best diagnosed in this view. Addition of color flow mapping is necessary for quantifying the regurgitation and in cases

The Echocardiographic Evaluation of Individual Mitral Lesions Supramitral Ring or Membrane75,76 (Figs 72.68 and 72.69) It is a circumferential ridge of fibrous tissue on the atrial surface of mitral valve attached to the base of the atrial surface of mitral leaflets. True incidence, although not well described, varies from 9 to 20% of reported cases of congenital mitral stenosis. In approximately 4% of cases, it is an isolated anomaly. The opening of the central orifice of the shelf-like projection decides the severity of mitral obstruction.

1612


Echocardiographically, supramitral ring (Figs 72.65A and B) is well seen in parasternal long- and short-axis views, and apical and subcostal four-chamber views. There are two variants of supramitral ring: • Small separation between mitral annulus and the ring during diastole—supra-annular variant. • Membrane firmly adhered to the mitral leaflets— annular variant.

A

B

Figs 72.65A and B: (A) Two-dimensional echocardiography in apical four-chamber view showing annular type of supramitral membrane; (B) Color flow mapping of the same showing turbulence starting from the supravalvular membrane. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 72.66: Two-dimensional (2D) echocardiography from an infant with cor triatriatum. Zoomed up apical four-chamber view on 2D echocardiography, showing a shelf in left atrium stretching from atrial septum on the right side to lateral wall of left atrium on the left with a narrow communication (arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

The second variety is difficult to image in real time and is best visualized by slow frame-by-frame playback examination of a held image. Majority of supramitral rings are nonobstructive. The obstruction is produced when their central lumen is small or when associated with a small mitral annulus, fusion of valve commissures, parachute mitral valve, or accessory mitral tissue. Color Doppler examination shows the site of actual obstruction by turbulent flow and spectral Doppler interrogation will provide the gradient across the mitral valve. Supramitral ring needs to be differentiated from cor triatriatum sinistrum (Figs 72.66 and 72.67). In cor triatriatum sinistrum, LA is divided into two chambers— superior and inferior by an abnormal diaphragm. The superior chamber receives pulmonary veins and inferior chamber communicates with left atrial appendage and mitral inflow. With supramitral ring, the stenosing ring is located much closer to mitral valve, lying between the mitral valve and left atrial appendage; another differentiating feature between the two is the movement of the diaphragm during systole and diastole. The best views to detect cor triatriatum are apical four-chamber, subcostal coronal, and PLAX views. In apical four-chamber view, the shelf is seen horizontally. The side attachment is to atrial septum and on left side to lateral wall of LA above the left atrial appendage. In PLAX view, the shelf stretches superiorly to the posterior aortic root and inferiorly to posterior left atrial wall. Color flow mapping shows that

Fig. 72.67: Two-dimensional echocardiography. Apical four-chamber view with color flow mapping showing turbulence (arrow) in a case of cor triatriatum. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).


with cor triatriatum, turbulence starts in mid left atrial cavity, but with supramitral ring, mosaic jet forms at just above the mitral valve. Supramitral ring is known to be associated with CoA, VSD, double-outlet RV, TOF, subaortic stenosis, bicuspid aortic valve, valvular aortic stenosis, complete AVSD, PDA, bicuspid pulmonary valve, ASD, abnormal tricuspid valve, persistent LSVC draining into coronary sinus, partial anomalous pulmonary venous connection (PAPVC), endocardial fibroelastosis, double aortic arch, hypoplastic LV, and coronary anomalies.

Hypoplastic Mitral Valve77–84 A hypoplastic mitral valve is nearly always associated with hypoplastic left heart syndrome (HLHS) or its variant. LA may be small in size. Mitral valve is often dysplastic with a small annulus, thickened leaflets, and short chordae, attaching directly into the left ventricular wall. The papillary muscles are poorly developed or rudimentary, with a very small left ventricular cavity. The LVOT including aortic arch is very small or atretic. An ASD is mostly present and LA is decompressed via the ASD. With restrictive ASD, left atrial pressure remains very high leading to severe pulmonary venous and arterial hypertension. During echocardiography in patients with hypoplastic left heart, mitral atresia, or severe mitral stenosis, interatrial communication should be carefully assessed for adequacy from subcostal views. Echocardiographic measurements suggesting the diagnosis of HLHS include an aortic valve annulus < 5 mm, mitral valve annulus < 9 mm, left ventricular inflow diameter < 21 mm, and end-diastolic left ventricular volume of < 20 mL/m2.

Dysplasia of Mitral Valve (Typical Congenital Mitral Stenosis)77,84 This condition is characterized by thickening of leaflets with rolled edges, fused commissures, short chordae with reduced interchordal spaces and poorly developed papillary muscles. The leaflets are thickened with limited mobility and show typical doming during diastole. They may also show nodularity on both atrial and ventricular aspects of the valve. Echocardiography from a combination of views, apical four-chamber, PLAX and short-axis views, reveal the detailed anatomy of mitral valve. Severity of the obstruction can be assessed by cross-sectional echocardiography along with Doppler interrogation of the gradient across the stenotic valve.

1613

Parachute Mitral Valve87,89 In this anomaly, all chordae tendineae of the mitral leaflets are attached to a single papillary muscle. The anterolateral papillary muscle is usually absent. Sometimes, there may be two papillary muscles adjacent to each other, producing a functional single papillary muscle. Echocardiographically, papillary muscles are best evaluated in PSAX view. Parachute mitral valve results in mitral stenosis due to reduced interchordal spaces. Chordae may also be short and thickened. Severity of stenosis is best evaluated by measurement of gradients across the mitral valve. This condition is often seen as part of the Shone’s complex. Other associations include VSD, double-outlet RV, and ASD.

Cleft Mitral Leaflet (Fig. 72.66)89–93 Isolated cleft in mitral valve is rare with a reported incidence of 15% of all congenital anomalies of the mitral valve. This is one of the few lesions of mitral valve, which is readily amenable to successful surgery. Generally, the cleft is in the anterior mitral leaflet, but a cleft in the posterior mitral leaflet has been reported. This condition should be differentiated from cleft in mitral valve associated with partial or complete AVSD. The cleft extends from the free margin to the annulus for a variable length and divides the leaflet into two equal parts. The leaflets may be normal or may be mildly dysplastic or thickened, producing variable degree of mitral regurgitation. The parasternal short-axis of the cleft is directed toward the LVOT. Cleft in mitral leaflet produces mitral regurgitation and color flow clearly shows the regurgitation originating from the cleft. The abnormality is best visualized in PSAX, apical four-chamber, and subcostal short-axis views. Cleft in anterior mitral leaflet is very commonly associated with AVSDs. However, it is not a true cleft but a commissure between the anterior and the posterior bridging leaflets. The major axis of this so-called cleft in AVSD is directed toward the interventricular septum.

Abnormal Mitral Arcade (Hammock Mitral Valve)87–89 (Figs 72.68 and 72.69) This is best seen on echocardiography from the atrial side of the mitral valve in PSAX, subcostal short-axis, and PLAX views. The valve has the shape of a funnel without commissures with a central orifice of variable size. Chordae are seen to cross the orifice, giving the appearance of a hammock. Thickened papillary muscles of LV may also

1614


Fig. 72.68: Two-dimensional echocardiography in a child with a hammock mitral valve showing thickened leaflets attached directly to the papillary muscle without intervening chordae with left atrium (LA) enlargement. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

Fig. 72.69: Two-dimensional echocardiography in a child with hammock mitral valve. Parasternal long-axis view showing the hammock mitral valve with mild mitral regurgitation and turbulence in left ventricular outflow tract (LVOT). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

B

Figs 72.70A and B: Two-dimensional echocardiography in apical four-chamber view (A) showing double orifice mitral valve with separate subvalvular apparatus; (B) Parasternal short-axis view at the level of the mitral valve showing the two separate orifices of equal size. (LA: Left atrium; LV: Left ventricle).

result in partial obstruction to left ventricular inflow. When examined from the left ventricular side in apical or subcostal four-chamber view or apical two-chamber views, one can see either direct insertion of the leaflets into the papillary muscles or insertion through short, thick chordae. Bridge of fibrous tissue adherent to the inferior aspect of anterior mitral leaflet may also be seen. This abnormality usually results in both mitral stenosis and mitral regurgitation. Abnormal mitral arcade may be associated with ASD, PDA, valvular and subvalvular aortic stenosis, and CoA.

Double Orifice Mitral Valve94–96 (Figs 72.70A and B) In this condition, there are two mitral orifices with separate leaflets, chordae tendineae, and papillary muscles. In 85% of cases, the orifices are of unequal size with smaller orifice situated close to the anterolateral commissure in 41% and close to the posteromedial commissure in 44%. Less commonly, there is a bridge of fibrous tissue between the two leaflets making two openings. The number of papillary muscles may vary from two to four.


Three varieties of double orifice mitral valve have been described: an incomplete bridge type, in which a small strand of tissue connects the anterior and the posterior leaflets at the leaflet edge level; a complete bridge type, in which a fibrous bridge divides the atrioventricular orifice completely into equal or unequal parts; and a hole type, in which an additional orifice with subvalvular apparatus is present in the posterior commissure of the mitral valve. They could be distinguished by sweeping the transducer in cross-sectional view from the apex toward the base of the heart. Variable extent of mitral stenosis and regurgitation is often present. The type of the defect does not predict the presence or severity of stenosis or regurgitation. Double orifice mitral valve is commonly associated with partial or complete AVSD, CoA, aortic stenosis, PDA, VSD, and ASD.

Accessory Mitral Orifice This abnormality results from a circular deficiency of mitral leaflet tissue. The size of the orifice can vary and the border of the accessory orifice is usually devoid of chordae tendineae. In some cases, chordae may insert into an independent papillary muscle. Accessory mitral orifice is best visualized in PSAX and subcostal four-chamber view with color Doppler interrogation. Apical four-chamber view may show the abnormality of the subvalvular apparatus. An abnormal position and orientation of a mitral regurgitant jet may help suspect this condition and warrants further evaluation in different views. This condition is sometimes associated with transposition of great arteries, partial AVSD, and interrupted IVC.

Ebstein’s Anomaly of Mitral Valve This is a rare anomaly with very few published case reports.97 Here, the LA is dilated and the posterior leaflet of mitral valve, which is dysplastic, is displaced downward with normal insertion of anterior mitral leaflet into the ventricular septum (above the septal tricuspid leaflet). Few case reports have shown associated thin left ventricular wall. This abnormality is best visualized in apical, subcostal four-chamber views and in PLAX view. The severity of mitral regurgitation can be assessed by color and spectral Doppler interrogation. Ebstein’s anomaly of mitral valve should not be confused with Ebstein’s anomaly of left atrioventricular valve in association with corrected transposition, where septal leaflet of morphological tricuspid valve is apically displaced.

1615

The reported associations include Ebstein’s anomaly of tricuspid valve, Marfan syndrome, double-outlet RV, ASD, PDA, CoA, hypoplasia of ascending aorta, and valvular aortic stenosis.

Mitral Valve Prolapse98–101 Mitral valve prolapse (MVP) results from myxomatous degeneration of the mitral valve, more commonly affecting the posterior leaflet; however, anterior or both leaflets can be effected, which balloons into the LA during systole, resulting in noncoaptation of mitral leaflets producing the typical click and murmur. The mitral leaflets show degenerative changes with elongated chordae. The chordae may sometimes get ruptured, producing severe mitral regurgitation. Diagnostic criteria are as follows: • Perloff et al. set the stage for accurately diagnosing MVP by expanding the diagnostic standards to include clinical and echocardiographic criteria98,99 • In a Framingham Heart Study, Freed et al. historically described echocardiographic criteria for MVP as classic versus nonclassic (see below)100 • Use of the PLAX view increases the diagnostic accuracy of MVP.101 Findings are as follows: • Classic MVP—The PLAX view shows > 2 mm superior displacement of the mitral leaflets into the LA during systole, with a leaflet thickness of at least 5 mm • Nonclassic MVP—Displacement is > 2 mm, with a maximal leaflet thickness of < 5 mm • Other echocardiographic findings that should be considered as criteria are leaflet thickening, redundancy, annular dilatation, and chordal elongation. Izumo et al. describes the superiority of using three-dimensional (3D) TEE (en face view) versus 2D TEE (commissural view) in patients with severe mitral regurgitation due to prolapse or flail mitral valve to assess the etiology with respect to quantification of prolapse segment and width. Based on the complex mitral valve anatomy, 2D TEE could not detect the largest prolapse gap and width, thus concluding 3D TEE superiority.101 MVP may be associated with connective tissue disorders or be idiopathic. The prolapse is best visualized in PLAX view, apical and subcostal four-chamber views, and apical two-chamber view. Severity of the prolapse can be graded by cross-sectional echocardiography and severity of regurgitation can be assessed by color Doppler. MVP is often associated with ASD secundum and rarely with VSD.

1616


Ebstein’s anomaly is characterized by apparent apical displacement of septal and posterior tricuspid valve leaflet insertion. The anterior leaflet is attached normally, but is elongated and is “sail-like.” The displacement of septal and posterior leaflets is caused by partial or complete adherence of these leaflets to the underlying myocardium. The incidence of this malformation varies from 0.03 to 0.6% of all CHDs. The disease comprises a spectrum of severity

from a mild displacement to a severe one and produces varying degree of low-pressure tricuspid regurgitation and rarely stenosis of the tricuspid valve. The commissure between the septal and posterior leaflet is the point of maximal displacement. These two leaflets are mostly dysplastic and of variable size. The RA dilates to a variable extent depending on the severity of tricuspid regurgitation. Tricuspid valve annulus is also enlarged. Because of the displacement of the leaflets, the RV is divided into two parts—the inlet portion of atrialized ventricle, which is thin-walled and often aneurysmal, and the trabecular and outlet portions, called functional RV. Few cases of Ebstein’s anomaly have an imperforate tricuspid valve with a muscular partition between the inlet and the trabecular portion of the RV. Presence of an ASD is seen in 65 to 93% of cases and in majority, it is either a stretched patent foramen ovale or a small ostium secundum type of defect. Apical four-chamber view shows sail-like anterior leaflet of tricuspid valve and is the view of choice for assessing the degree of septal leaflet displacement, and the apical four-chamber view with posterior tilt will profile displacement of posterior leaflet. The PLAX view when tilted toward RV inflow also shows the abnormally placed tricuspid valve. A septal leaflet displacement of > 8 mm/m2 has been found to be a sensitive indicator of the diagnosis. Also, an absolute value of displacement of > 15 mm in children of < 14 years, or > 20 mm in adults helps in echocardiographic diagnosis of Ebstein’s anomaly, discriminating it from the normal variations and position of tricuspid valve with marked right atrial enlargement.

A

B

Table 72.11: Various Congenital Lesions of the Tricuspid Valve

Ebstein’s anomaly Tricuspid valve dysplasia Tricuspid valve prolapse Double orifice tricuspid valve Parachute deformity Congenitally unguarded tricuspid orifice Tricuspid atresia

CONGENITAL ABNORMALITIES OF TRICUSPID VALVE (TABLE 72.11) Apart from Ebstein’s anomaly, other congenital anomalies of the tricuspid valve apparatus (valve annulus, valve leaflets, chordae tendineae, and papillary muscles) are not very common. Dysplastic valve with varied abnormalities can occasionally be seen.

Ebstein’s Anomaly of the Tricuspid Valve102–111 (Figs 72.71A and B)

Figs 72.71A and B: Two-dimensional echocardiography in a patient with Ebstein’s anomaly of tricuspid valve. (A) Apical four-chamber view with slight leftward tilt showing the apical displacement of the septal leaflet of tricuspid valve (arrow), (+) shows the normal site of attachment of TV, enlarged right atrium, atrialized right ventricle, and reduced size of the functional right ventricle; (B) Apical fourchamber view with posterior tilt (at the plane of coronary sinus) showing displaced posterior leaflet of tricuspid valve. (ARV: Atrialized right ventricle; CS: Coronary sinus; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).


Anterior tricuspid leaflet, although normally attached at the tricuspid annulus, is rarely completely normal. Because of its sail-like nature and abnormal attachment to the ventricular wall and papillary muscle, it may cause RV inflow obstruction. The anterior leaflet may be joined to the posterior or septal leaflet as a hammock-like structure producing functional tricuspid stenosis. Ebstein’s anomaly may be associated with significant RVOT dilatation and RV dysfunction. It may also be associated with left ventricular dysfunction and variable degree for left ventricular fibrosis and hypertrophy. Adequacy of functional RV determines the treatment strategy of future single or two-ventricle repair. In a subset of patients with Ebstein’s anomaly with small functional RV and significant desaturation, a Glenn or Fontan type of surgery is indicated. The usual Ebstein’s anomaly is always associated with situs solitus and atrioventricular and ventriculoarterial concordance. However, Ebstein’s anomaly may involve the left atrioventricular valve in atrioventricular and ventriculoarterial discordance. Here, the nature of the displacement and formation of the septal and posterior leaflets are similar, but the anterior leaflet is smaller and not elongated or sail-like. Also, the left atrioventricular valve regurgitation is of high pressure in comparison to low-pressure tricuspid regurgitation in Ebstein’s anomaly of usual type. Associated defects in Ebstein’s anomaly are rare and include VSD, PDA, partial AVSD, pulmonary stenosis, pulmonary atresia, and MVP. In order to grade the severity of the Ebstein deformity using echocardiography, Celermajer et al.107 described

A

1617

the following ratio: RA + aRV/RV + LV + LA (RV = area of the RV, RA = area of the RA, aRV = atrialized portion of the RV at end diastole, LA = area of the LA, LV = area of the LV); all the measurements are made in end diastole. These are graded as Grade I (ratio < 0.5), Grade II (ratio from 0.5–0.99), Grade III (ratio from 1.0–1.49), and Grade IV (ratio > 1.5), with Grade I having the best prognosis while Grade IV, the worst prognosis.

Tricuspid Valve Prolapse111 As an isolated anomaly, tricuspid valve prolapse is rare. It is more commonly seen in association with MVP. There is similar myxomatous degeneration of the tricuspid valve leaflets with thinned leaflets and elongated chordae. PLAX view permits evaluation of septal and posterior leaflets. The anterior and septal leaflets are best visualized from the PSAX and from apical and subcostal four-chamber views. In approximately 40 to 48% of cases, there is associated MVP.

Congenitally Unguarded Tricuspid Orifice1,2,112 Here, the orifice between the RA and the RV is normal, but there is no tricuspid valve apparatus. There is either complete absence of valve or only remnants of valvular tissue are present. The close differential includes dysplastic tricuspid valve (Figs 72.72A and B). Usually, the RA is dilated and the RV is hypoplastic. This anomaly is best visualized in apical and subcostal four-chamber views as well as in long-axis parasternal inflow view. Severe low-pressure tricuspid regurgitation is invariably present. Associations include pulmonary

B

Figs 72.72A and B: Two-dimensional transthoracic echocardiography. Apical four-chamber view with color compare in a case of severely dysplastic tricuspid valve showing markedly enlarged right atrium and severe tricuspid regurgitation. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1618


A

B

C

Figs 72.73A to C: Two-dimensional transthoracic echocardiography in a case of Uhl’s anomaly. (A) Apical four-chamber view showing dilated thin walled RV (arrow) and dilated tricuspid orifice with tricuspid valve (arrow). (B) Parasternal short-axis view with Uhl’s anomaly showing dilated right atrium with thinned out tricuspid valve (arrow). (C) Subcostal sagittal view of the same patient showing thin tricuspid valve and the lack of apical trabeculations of right ventricle (arrow).

atresia with intact ventricular septum, ASD, PDA, doublechambered RV, cor triatriatum, VSD, Uhl’s anomaly113 (Figs 72.73A to C), and LSVC draining into RA.

Uhl's Anomaly113 Though not a disease of the tricuspid valve it is discussed here because it mimics the presentation of Ebstein anomaly of TV or dysplastic TV closely. Uhl’s anomaly

is characterized by the apposition of the epicardium and endocardium essentially because of the absence of the myocardial layer. Closest differential diagnosis is arrythmogenic right ventricular dysplasia but Uhl's is not familial unlike latter. Echocardiography would show thinned out parchment-like appearance of the ventricular wall (Figs 72.73A to C). Diastolic opening of the pulmonary valve may be seen in some cases. MRI remains the investigative modality of choice.

PART 5: LEFT VENTRICULAR OUTFLOW TRACT OBSTRUCTION LVOT obstruction can occur at various levels: • Valvular aortic stenosis • Subvalvular aortic stenosis • Supravalvular aortic stenosis.

VALVULAR AORTIC STENOSIS Congenital bicuspid aortic valve occurs in 1.3% of the population114–118 and, therefore, is one of the most common


congenital heart malformations. Valvar aortic stenosis is the most common type of LVOT obstruction accounting for 70 to 91% of aortic obstructions. It is caused by cusp deformities, either with or without narrowing of the “annulus.” It may manifest in the neonate or progressive obstruction may develop in an inherently abnormal valve. The echocardiographic study of valvular aortic stenosis should include the following:114-119 • Morphology of the stenotic valve • Dimensions of the aortic root • Severity of valvular obstruction • Left ventricular hypertrophy and function, and • Associated anomalies.

1619

The PSAX view at the base of the heart and long-axis view are best views to determine the morphology and number of cusps. Normally, the tricuspid aortic valve has three cusps of nearly equal size. Three commissures form a Y-shaped pattern in diastole. In systole, the leaflets open along these commissures to create a wide-open triangular orifice. The congenital anomalies of aortic valve comprise a spectrum of deformities, which include a decrease or increase in the number of valve cusps, their form, and size. Normal aortic valve leaflets are thin with unrestricted mobility. In stenotic valves, leaflets are thickened and domed in systole. Doming of valve leaflets during systole occurs due to limited cusp separation leading to restricted mobility of valve cusps. Subcostal coronal with anterior tilt, apical four-chamber with anterior tilt, and PLAX views are

particularly useful to define the valve motion. PSAX view is the best view to define the number of cusps and cusp morphology. Following variations occur in the aortic valve morphology: • Unicuspid aortic valve is separated pathologically into two types—acommissural and unicommissural. The acommissural valve is a rare anomaly and has a single membrane-like leaflet with a central circular orifice. The orifice is typically eccentric and circular in systole. In diastole, an eccentrically located valve closure is seen with raphae. Unicommissural valve is frequently seen in symptomatic neonates with aortic stenosis.In systole, the opening of the valve is eccentic and circular while in diastole raphe is seen and valve closes eccentrically. The unicuspid valve is generally stenotic in neonatal period, although occasionally it has sufficient redundancy and may be the cause of obstruction in later life. • Congenital bicuspid aortic valve (Figs 72.74A and B) occurs in about 2% of the general population. It is formed by the fusion of two cusps. The fusion of left and right coronary cusps results in a bicuspid valve with two cusps positioned anteroposteriorly with the commissures to the right and left. The fusion of right and noncoronary cusps results in two cusps positioned right and left, and the two commissures have an anteroposterior orientation. In some cases, fused commissures called raphe are seen on echocardiography and in the closed position may give the appearance of a tricuspid aortic valve. It is only in systole that the valve does not open along the fused commissure. The development of aortic valve

A

B

Morphology of Stenotic Aortic Valve

Figs 72.74A and B: Two-dimensional transthoracic echocardiography. (A) Parasternal short-axis view showing bicuspid aortic valve in diastole with single closure line of fusion; (B) The same patient in systole showing the fused right and noncoronary cusps of the aortic valve (arrows). (LA: Left atrium; RA: Right atrium; RV: Right ventricle).

1620


A

B

Figs 72.75A and B: (A) M-mode cut across the aortic valve and left atrium showing eccentric closure of the thickened aortic valve; (B) Showing the same across the normal valve for comparison.

Fig. 72.76: Two-dimensional echocardiography with parasternal short-axis view showing a quadricuspid aortic valve. (Ao: Aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle).

stenosis is variable and may be related to valvular characteristics. Patients with anteroposteriorly (as opposed to right-left) and eccentric (vs symmetric) valve leaflets have faster rate of progression of aortic obstruction. Patients with fusion of right coronary and noncoronary leaflets are more likely to have aortic regurgitation. Combination of bicuspid aortic valve and aortic coarctation is usually associated with milder aortic valve disease. – The echocardiographic diagnosis of a bicuspid aortic valve is based on demonstration of two cusps and two commissures on PSAX view. Additional features that support the diagnosis include leaflet redundancy, infolding, and eccentric valve closure.

In PLAX view, an abnormal eccentric coaptation line (best seen on M-mode) with systolic leaflet doming and an abnormal pattern of systolic opening is seen (Figs 72.75A and B). – Although there is no fixed pattern of coronary artery origin with a bicuspid aortic valve, usually the coronary arteries emerge from the anterior sinus in case of anterior and posterior cusps with normally related great vessels. In presence of right and left cusps, LCA arises from anterior part of left sinus, and right coronary from anterior part of right sinus. • Congenitally stenotic tricuspid aortic valve has three aortic cusps. The edges of the cusps are rolled or gnarled with varying degrees of commissural fusion. This abnormality is often associated with a narrowed aortic annulus. • Quadricuspid aortic valve (Fig. 72.76) is a very rare (0.013%) congenital anomaly. No correlation has been found between anatomical variation in the size of cusps and functional status. Although aortic stenosis is rare, approximately 50% of cases have aortic insufficiency. Aortic regurgitation is more common with a small accessory cusp. – In the PSAX view, four diastolic closure lines are present forming a characteristic “X” pattern, and in systole, four cusps open and form a rectangular configuration. Color flow mapping will show presence of aortic regurgitation if present. Pentacuspid aortic valve and hexacuspid aortic valves have been described in case reports.


1621

Sinotubular Junction Sinotubular junction is the point of the union of the aortic sinuses and the tubular portion of the ascending aorta. The apex of the aortic valve commissures correspond to the sinotubular junction. PLAX view is the best view to measure the aortic valve annulus, the thickness and mobility of the leaflets, the plane of the valvular orifice, the sinuses of Valsalva, the sinotubular junction, and the proximal portion of the ascending aorta.

Severity of Aortic Stenosis119–121 Fig. 72.77: Two-dimensional echocardiography with parasternal long-axis view of left ventricular outflow showing measurements. (A: Annulus; B: Aortic sinuses; C: Sinotubular junction; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

Aortic Root (Fig. 72.77) The aortic root is the portion of the ventricular outflow tract that supports the leaflets of the aortic valve delineated superiorly by the sinotubular junction and inferiorly by the ventricular junction. The aortic root acts as an individual hemodynamic entity; integrity of all its components is essential for normal function. Aortic root dimensions are assessed at four levels: the annulus, the sinuses of Valsalva, sinotubular junction, and the proximal ascending aorta. The aortic root dimensions should be routinely measured, as it is often dilated in the presence of bicuspid aortic valve, irrespective of associated hemodynamic disturbances. This progressive dilatation of aortic root is not prevented even after aortic valve replacement; as such cardiologists recommend reconstruction and remodeling of dilated aorta at surgery for bicuspid aortic valve patients.

Aortic Valve Annulus Ventriculoarterial junction anatomically corresponds to the insertion of the arterial trunk into the ventricular mass that supports it. In the LV, this insertion acquires the shape of a fibromuscular ring and is described as aortic annulus. The muscular portion corresponds to the left ventricular myocardium, which supports the valve, and the fibrous portion corresponds to the insertion at the level of the fibrous continuity between the aortic and mitral valve leaflets.

Direct quantitative assessment of the severity of aortic valvular stenosis can be obtained using Doppler echocardiography. At the same time, one should also look for associated left ventricular hypertrophy and left ventricular diastolic and systolic dysfunction. Normal aortic valve blood flow is laminar and peak systolic velocity of blood flow across the aortic valve rarely exceeds 1.5 m/s. In aortic valve stenosis, the LV generates high pressures to overcome the obstruction, resulting in both turbulent flow and increased velocity across the valve. The pulsed wave (PW) Doppler helps in localizing the site of obstruction by demonstrating low velocity in the LV outflow and increased velocity across the aortic valve. However, continuous wave Doppler is required to quantitate the valvular obstruction. The jet velocities distal to the stenotic aortic valve orifice are recorded from multiple views—subcostal, apical, right parasternal, and suprasternal views. The velocity of the aortic stenosis jet is defined as the highest continuous wave Doppler signal obtained from any window. Only well-defined envelopes should be used for quantification of velocities to obviate significant errors. The ultrasound beam must be aligned parallel to the flow for accurate velocity recording guided by 2D image and color flow. Angle correction should be avoided. Underestimation of stenosis severity can occur due to a nonparallel intercept angle. At higher velocities, a small error may lead to significant errors of gradients because of the quadratic relation between velocity and pressure gradient. The usual cause of overestimation of aortic stenosis is if one interrogates the mitral regurgitation signal mistakenly. Both jets occur in systole and in the same direction. A difference in timing may be helpful as the mitral regurgitation signal velocity starts during isovolumic contraction and continues through isovolumic relaxation,

1622


and the aortic stenosis signal start after the isovolumic contraction during aortic ejection. The velocity determination across the aortic valve is flow-related. Hence, conditions causing increased flow such as aortic regurgitation and elevated cardiac output as seen in anemia, anxiety, pregnancy, and exercise will increase the flow velocity across the aortic valve. Hence, it is also necessary to determine the velocity proximal to the aortic valve and do the necessary correction in Bernoulli’s equation. Conditions associated with low cardiac output such as left ventricular failure commonly seen in neonatal or elderly aortic stenosis preclude the use of valve gradient as an indicator of severity of valvular stenosis. Another physiological issue that needs to be considered in the Doppler assessment of pressure gradients in patients with aortic stenosis is the phenomenon of distal pressure recovery. The fluid dynamics of valvular aortic stenosis are characterized by a laminar high-velocity jet in the narrowed orifice, with the narrowed segment of the flow stream (the vena contracta) occurring downstream from the anatomical valve orifice. As the jet expands and decelerates beyond the vena contracta, the associated turbulence results in an increase in aortic pressure “pressure recovery” such that when aortic pressure is measured in the distal ascending aorta, the left ventricular to aortic pressure difference is less than if aortic pressure is measured in the vena contracta.

• •

• •

Doppler mean gradient is comparable to mean pressure gradient measured at the cardiac catheterization As Doppler mean gradient is the average of all the peak instantaneous gradients throughout the systole, and not on single peak velocity, it can be obtained with greater accuracy and reproducibility Mean gradient is less affected by transvalvular flow. Mean gradient is the basis of calculation of valve area using the Gorlin equation.

Aortic Valve Area The calculation of aortic valve area is a useful method for determining the severity of the stenosis independent of transvalvular flow in contrast to pressure gradient across the valve. In children where the decision regarding severity of aortic stenosis remains unanswered in patients with intermediate pressure gradients, determination of aortic valve area should also be performed. Aortic valve area can be measured by the following methods: • Planimetry—The aortic valve area can be measured by direct tracing from PSAX view at the level of great vessels on 2D echocardiography. There are some limitations in pediatric patients as – Fast heart rate leading to limitation of frame rates. – Error in measurement of small orifice. – Irregular valve opening that is difficult to trace. Aortic valve area by continuity equation:

122–128

Pressure Gradients

Transvalvular pressure gradients are usually calculated from Doppler aortic velocity profiles. The peak gradient and the mean gradient are measured. The peak gradient is determined from the peak velocity using the modified Bernoulli equation (p = 4V2), and mean gradient by averaging all the peak gradients in a systolic ejection period. In general, the Doppler-measured peak gradient may not correspond to the catheter measured peakto-peak pressure gradient, because Doppler measures instantaneous peak-to-peak gradient, which is fundamentally different from the peak-to-peak catheter “gradient” usually calculated in the cardiac catheterization laboratory. In some children, especially with moderate degree of stenosis, two measurements can differ by as much as 30 mm Hg. Mean gradients, measured by averaging the instantaneous catheter or Doppler gradients over the systolic ejection period, correspond more closely to each other. The Doppler mean gradient has several advantages over the Doppler peak instantaneous gradient.

CSAav =

CSALvot × VTILvot VTIav

CSA = Cross sectional area of aortic valve. V TI = Velocity time integral. av = Aortic valve. Lvot = Left ventricular outflow tract.

Critical Neonatal Aortic Stenosis129–139 In infants presenting with signs of aortic stenosis in the first few months of life, echocardiography provides a rapid noninvasive diagnostic method. • The aortic valve leaflets are thickened and domed. In many cases, the leaflets are immobile and a clear systolic opening may not be visualized. The annulus usually measures 5–8 mm • Usually, there is post-stenotic dilatation of the ascending aorta and the ratio of the ascending aorta to the annulus is more than 1.0. This phenomenon


characterizes a LV, generating a pressure gradient across the aortic valve leading to release of energy in the ascending aorta and post-stenotic dilatation • The LV is thickened and hypertrophied • Increased echogenicity of the mitral valve and papillary muscles is seen in PSAX, parasternal long-axis, and apical four-chamber views • Redirection of fetal flow patterns and delayed regression of PVR results in the RV and the main PA being enlarged. If the ventricular function is normal, the peak velocity across the valve is increased. More often, neonates present with severe left ventricular dysfunction, and differentiation from dilated cardiomyopathy becomes important. In the latter case, the aortic valve is normal with no evidence of post-stenotic dilatation. However, associated cardiomyopathy is difficult to rule out in some cases and is only diagnosed retrospectively if the ventricular contractility fails to improve after relief of aortic stenosis.

Aortic Stenosis Versus Hypoplastic Left Ventricle In some infants dilated RV may dwarf the LV, which appears small or even hypoplastic. The following features help to differentiate and indicate small LV: • The evaluation of shape of the LV may be useful in these cases. Normal LV is usually ellipsoid and extends to the cardiac apex in four-chamber view. But the hypoplastic LV is globular and does not extend to cardiac apex • LV inflow dimension (hinge point of posterior mitral leaflet to cardiac apex of < 25 mm) • Mitral valve annulus diameter of < 9 mm • Ventriculoaortic junction of < 5 mm, (all measured from apical four-chamber or long-axis view at enddiastole will indicate hypoplastic LV) • Left ventricular cross-sectional area measured in the PLAX view that included the mitral valve, aortic valve, and left ventricular apex at end diastole of < 2 cm, usually predicts hypoplastic of LV and nonsurvival after balloon aortic valvotomy • Predominant or total antegrade flow in the ascending aorta and transverse arch is indicative of an adequate LV • A new discriminant analysis was found to more accurately predict survival with a biventricular circulation than with the model using the traditional criteria. The new criteria first emphasized the need

1623

for having an adequate mitral valve by acquiring the mitral valve area (calculated by assuming the morphology was that of an ellipse with radii measured from the PLAX and apical four-chamber views) to have a z-score of > −2. Only then can the new criteria be applied. These criteria consist of (a) aortic annulus z-score measured from the PLAX view, (b) ratio of the long axis of the LV to the long axis of the heart, (c) endocardial fibroelastosis grade: none, mild (affecting papillary muscles only), moderate (affecting papillary muscles and some of the endocardium), and severe (affecting papillary muscles and extensive portions of the endocardium). A new regression equation was developed: Score = 10.98 (BSA) + 0.56 (Aortic annulus z –score) + 5.89 (LAR) – 0.79 (EFEgrade) – 6.78 where EFE grade is 0 for none or mild, and 1 for moderate or severe. The threshold score for survival to be better with biventricular versus univentricular repair is > −0.65.

Hemodynamics The LV becomes hypertrophied with increasing left ventricular outflow obstruction. Severe unrelieved obstruction may lead to an oxygen demand/supply mismatch leading to subendocardial ischemia and fibrosis. Ventricular systolic function is assessed by the conventional methods of calculating shortening fraction and ejection fraction. This is an important parameter in the echocardiographic assessment of an aortic stenosis patient as the assessment of severity by pressure gradients depends upon ventricular function. A decrease in function decreases the transvalvular flow and the gradients no longer reflect the severity of obstruction. Diastolic ventricular function is assessed by the filling abnormalities of the LV. From the mitral valvular Doppler recording peak flow velocities, filling rates and proportion of flow in various phases of diastole may be assessed. Comparative studies of these subjects with normal controls have revealed higher E-velocity, a much higher A-velocity, therefore an inverse E/A ratio. The percentage of total Doppler area in the first third of diastole was significantly lower and the percentage of the total Doppler area under the A-wave was higher. M-mode tracing in PLAX view at the mitral valve may show a b-bump or a c-interruption if the LVEDP is elevated.

1624


Associated Anomalies129-135 A PDA is seen in 20 to 65% cases of valvular aortic stenosis. CoA is found in 11 to 53% cases and stenosis of the mitral valve in 25% cases. Other anomalies like VSD and mitral valve abnormalities are also common and should be looked for.

SUBVALVULAR AORTIC STENOSIS Subvalvular aortic stenosis is responsible for 8 to 30% of cases of LVOT obstruction and corresponds to 1.2% of all cardiac anomalies.135-140 Classically, the subvalvular aortic stenosis has been divided into fixed and dynamic

Fig. 72.78: Two-dimensional echocardiography in parasternal long-axis view showing subvalvular aortic stenosis with accessory tissue of mitral valve (arrow). (Ao: Aorta; LV: Left ventricle; RV: Right ventricle).

Fig. 72.79: Two-dimensional echocardiography in parasternal long-axis view showing the ventricular septal defect (VSD; star) with posterior malalignment of the outlet septum (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

obstruction. Dynamic obstruction is part of hypertrophic cardiomyopathy and systolic anterior motion of mitral valve, not being discussed in this chapter. Echocardiographic evaluation of fixed subvalvular aortic stenosis includes: • Cause of subvalvular stenosis. • Presence of aortic regurgitation. • Associated anomalies. • Severity of obstruction. Cause of subvalvular aortic stenosis.140–150 There are several types of fixed subaortic obstructions: • Discrete fibrous membrane (Fig. 72.78). • Fibromuscular collar. • Tunnel subaortic stenosis. • Posterior displacement of infundibular septum with discrete narrowing of the LVOT (Fig. 72.79). • Other less common causes are accessory mitral valve tissue or tissue arising from membranous septum protruding into LVOT, systolic anterior motion of anterior leaflet of mitral valve as in cases of hypertrophic cardiomyopathy (Figs 72.80 to 72.82). Most commonly, a discrete fibrous membrane or fibromuscular shelf encircles the LVOT. Rarely, it extends for a longer distance (more than one third of aortic diameter) and forms a tunnel-shaped obstruction. Abnormal tissue may extend and tether the aortic valve or the anterior mitral leaflet. Fixed subaortic obstruction usually occurs in association with other defects in 64–70% of the cases and is often diagnosed when the child is investigated for them.

Fig. 72.80: Two-dimensional echocardiography. Parasternal longaxis view in a child with discrete subaortic membrane showing anterior insertion of the membrane to the ventricular septum below the right aortic cusp (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).


1625

Fig. 72.81: Two-dimensional echocardiography. Parasternal longaxis view in a 2-year-old child with discrete circumferential subaortic membrane (arrows) close to aortic valve. (Ao: Aorta; LA: Left atrium, LV: Left ventricle; RV: Right ventricle).

Fig. 72.82: Two-dimensional echocardiography. Parasternal longaxis view in a child with hypertrophic obstructive cardiomyopathy showing the severely hypertrophied interventricular septum and systolic anterior motion of the anterior leaflet of the mitral valve (arrow). (LA: Left atrium; LV: Left ventricle; RV: Right ventricle Ao: Aorta).

Echocardiographically, subaortic stenosis can be studied from the parasternal long-axis, the apical fourchamber, and subcostal coronal views with anterior tilt. Membranous subaortic stenosis appears as a discrete shelf adherent to the interventricular septum beneath the aortic valve or up to 2.5 cm below it. The PLAX view is highly sensitive in detecting discrete subaortic stenosis; however, in most cases, the anterior insertion alone is visualized because the membranous diaphragm being directed posteriorly toward the left ventricular posterior wall and mitral valve is aligned parallel to the ultrasound beam in the PLAX view. In some cases, however, with careful interrogation, anterior insertion to ventricular septum below the right aortic cusp and posterior insertion to the base of anterior mitral leaflet insertion can both be seen. In four-chamber subcostal coronal views with anterior tilt, the ultrasound beam is perpendicular to the subaortic ridge and profiles the anatomy of membrane better. Careful PSAX scans of the LVOT are more likely to visualize the extent of attachment of the membrane. The membrane may come in and out of the plane of PSAX section very quickly because of rapid cardiac motion and, frame-by-frame analysis is required to assess it adequately. In the majority of cases, it has the shape of a horseshoe; rarely is it a complete ring and in most cases only one insertion is visualized at a given time. Luminal diameter is not a criterion for severity of obstruction. With discrete subaortic stenosis, the jet of stenosis often damages the aortic valve leading to thickened aortic valve on 2D echocardiography. Color flow mapping reveals presence

of aortic regurgitation. In contrast to bicuspid aortic valve, there is no post-stenotic dilatation of the ascending aorta. The fibromuscular collar is a thick muscular ring that forms at a lower level in LVOT than the subaortic membrane and is seen easily in parasternal long-axis, four-chamber (apical and subcostal coronal) with anterior tilt as a thick fibrous shelf projecting into LVOT. A fibromuscular tunnel is diagnosed by the same views and gives the appearance of a long narrow tract of subaortic narrowing. Posterior displacement of outlet septum: Subaortic stenosis due to posterior malalignment of outlet septum occurs with a nonrestrictive perimembranous VSD. This subgroup usually has associated arch anomalies such as CoA or arch interruption. Best view to profile malalignment of outlet septum is parasternal long-axis, although four-chamber views with anterior tilt also define the posterior malalignment of outlet septum leading to subaortic narrowing. Arch anomalies should be defined in detail from suprasternal views in these cases. With subaortic stenosis, on M-mode trace the aortic valve leaflets shows a slight flutter and early to mid systolic closure along with other evidence of significant left ventricular outflow obstruction such as left ventricular hypertrophy. Doppler echocardiography quantitates the degree and site of obstruction. Color Doppler illustrates the flow acceleration at the site of stenosis and aliasing velocities beyond that. It helps in positioning the ultrasound beam parallel to the left ventricular outflow in various views. The total gradient across the left ventricular outflow is quantitated by continuous wave

1626


Doppler using the modified Bernoulli’s equation. The right infraclavicular view with the patient turned toward the right usually records the highest velocities. PW Doppler is used to localize the site of outflow obstruction by placing the pulsed Doppler sequentially and noticing the site of increase in outflow velocity. In diffuse tunnel obstruction, the maximal velocity is produced inside the tunnel and this can be missed altogether by Doppler and catheter techniques, at times. In these latter cases, the pressure drop caused by viscous friction along the tunnel may cause a lower Doppler velocity to be recorded, resulting in an underestimation of the true gradient. The tunnel subaortic stenosis may be associated with a narrow aortic annulus and often causes significant concentric left ventricular hypertrophy. In infants with CoA or arch interruption, reduced aortic valve diameter and increased mitral–aortic separation could be precursors to subaortic obstruction. The extension of subaortic fibroelastic tissue to involve the aortic root at the site of insertion of the aortic valve cusps and increasing fibrosis of the aortic root may be responsible for this discrepancy. The size of the aortic root has a marked effect on the optimal relief of the fixed subaortic stenosis. In patients with fixed subaortic stenosis, the aortic root can be small (25%) and should be measured preoperatively because in the presence of small aortic root, a special surgical technique is required. There is a 13% incidence of left ventricular outflow abnormalities in immediate family members. Hence, their screening is an essential part of patient evaluation. In 65 to 70% of cases of subaortic obstruction, associated defects are present and

include VSD, CoA or arch interruption, bicuspid aortic valve, supravalvular mitral stenosis, and persistence of the LSVC with dilated coronary sinus causing restrictive left ventricular filling. Discrete subvalvular aortic stenosis is a progressive lesion. Fixed subaortic stenosis has been noticed to progress more rapidly in the presence of associated lesions than isolated subaortic stenosis. This implies that careful screening should be done for associated lesions in all cases of discrete subaortic stenosis. Tethering of mitral and aortic valves is also known to develop subsequently in serial echocardiograms. Even after adequate surgical relief, this lesion is known to recur and patients require long-term follow-up. Aortic insufficiency can also progress and should be carefully evaluated in follow-up of cases of discrete subaortic stenosis. The distance between the diaphragm and the aortic valve should be noted in the initial echocardiogram. The mechanism responsible for aortic regurgitation is believed to be repetitive trauma caused by the high velocity jet through the subvalvular stenosis as well as extension of the fibroelastic tissue of discrete subaortic stenosis toward the base of one or more aortic cusps.

Fig. 72.83: Two-dimensional echocardiography. Apical fourchamber view with anterior tilt and color flow mapping in a case of supravalvular aortic stenosis. The turbulence (arrow) begins above the level of the aortic valve (arrow). (AA: Ascending aorta; LV: Left ventricle).

Fig. 72.84: Two-dimensional echocardiography. Parasternal long-axis view of the left ventricular outflow tract showing severe stenosis at the level of the sinotubular junction (arrow) in a patient with supravalvular aortic stenosis. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

SUPRAVALVULAR AORTIC STENOSIS (FIGS 72.83 AND 72.84)151–154 Supravalvular aortic stenosis is the rarest of left ventricular outflow obstructions (2–11%). It occurs at the sinotubular junction and produces a localized or diffuse narrowing.


This is a group of lesions with varying anatomy and is characterized into three types: • Membranous type (<25%) • Hourglass type (50–75%) • Uniform hypoplasia of the ascending aorta (<25%). During an echocardiographic diagnostic study, the following anatomical features need to be defined: • Morphology and severity of supravalvular aortic stenosis • Anatomy of the aortic valve • The coronary anatomy • Associated anomalies.

Morphology The obstruction is best imaged in parasternal long-axis, apical five-chamber and subcostal views of the LVOT, or suprasternal long- and short-axis views and high right parasternal views. In the parasternal and apical fivechamber views in the normal heart, the aortic diameter increases at the level of the sinuses of Valsalva and then decreases at the superior border of the aortic sinuses. The diameter of the ascending aorta above the aortic sinuses is, however, the same as the diameter of the ventriculoaortic junction or aortic root in the normal heart. The detection of obstruction in hourglass deformity depends upon visualization of an obvious decrease in the caliber of the vessel relative to the surrounding normal areas, namely at sinotubular junction, then some dilation, and narrowing again. The following measurements are taken in the PLAX view: (a) aortic annulus, (b) maximal diameter at sinuses of Valsalva, (c) sinotubular junction, (d) narrowest part, and (e) aorta distal to the obstruction. Measurements are taken from the inner aspect of the aortic root echo to the inner aspect of the posterior root echo. Careful attention should be paid to aligning the probe so that long axis of the vessel and adequate visualization of the lumen both proximal and distal to the area of obstruction is obtained. Oblique angulation of the cross-sectional scan plane to vascular lumen may give the appearance of the aorta being cut-off as beam passes obliquely through the lateral wall of the vessel. Normally, the diameter of the sinotubular junction is either equal or slightly (12.5%) more than the diameter of the aortic annulus. In supravalvular aortic stenosis, a percentage decrease of > 25% from the annulus is noted. There is a rough correlation in the percentage decrease

1627

in diameter with catheter peak gradients. In the diffuse type of supravalvular aortic stenosis, the aortic hypoplasia extends from the sinotubular junction to the innominate artery. Usually, the aortic arch and arch vessels are also involved. A severely hypoplastic and narrowed segment may have retrograde flow from PDA supplying the arch vessels and the descending aorta. When the aorta is diffusely hypoplastic, the annulus is frequently also involved and can no longer be used as a reference for estimation of severity. The membranous lesion generally appears as a discrete, linear echo extending inward from the walls of the aorta and encroaching on the vascular lumen. The membrane is typically located at the sinotubular junction just above the insertion of the superior LA wall into the posterior aortic root. The separation between the inner margins of an obstructive membrane is less than the diameter of the outflow tract at the annulus. Doppler interrogation aids in confirmation of diagnosis. The site of stenosis is confirmed both by color flow and pulsed Doppler, while maximal velocity is obtained by continuous wave Doppler. The jet flow of supravalvular aortic stenosis is often directed toward the innominate artery; consequently, the highest value of the peak velocity is often obtained by aligning the Doppler beam parallel with the innominate artery in the suprasternal views. Pressure gradient across the aortic root is calculated from the modified Bernoulli’s equation and correlates with catheter-measured peak-to-peak gradient across the fibrous diaphragm. However, in hourglass deformity, gradual re-expansion of the aorta distal to stenosis leads to pressure recovery and discrepancy between Doppler and catheter-measured gradients.

Aortic Valve Anomalies Aortic valve abnormalities have been reported in 25 to 45% of the cases. It is important to assess the dynamics of aortic valve motion throughout the cardiac cycle. In diastole, the valve may function normally; however, in systole its motion can be limited and the opening incomplete due to spatial restriction; this has been called “pseudovalvular” stenosis. The presence of bicuspid aortic valve, valve thickening, and commissural fusion have been reported in a high percentage of cases. Aortic valve regurgitation has been reported in 13 to 66% cases of supravalvular aortic stenosis and needs careful evaluation. Anomalies of aortic valve can be seen in the same view as described for valvular stenosis.

1628


Coronaries Coronary artery abnormalities are invariably associated and may be: • Dilated and tortuous coronary arteries due to exposure to high systolic pressures proximal to the site of obstruction (rarely coronary artery aneurysms have been reported) • Coronary orifice can be narrowed by the overhanging, fibrous bridge. • Rarely, the orifice of coronary artery can be completely obstructed as the valve cusps become adherent to the aortic wall. With the patient in the left lateral position, the transducer is placed in the left parasternal position to obtain a short-axis view of the great vessels. Slight adjustment of the imaging plane, so that it traverses the heart below the pulmonary trunk, allows for visualization of the origin and proximal portion of coronary arteries. The ostia and the coronaries should be carefully assessed for dilatation, tortuosity, or narrowing. The apical fourchamber view demonstrates RCA coursing along the right AV groove and aiming the transducer superiorly toward the left ventricular outflow, the branching of left anterior descending (LAD), and left circumflex may be seen besides their profiling in the PSAX view. In severe cases, myocardial ischemia and infarction have been reported as such regional wall motion abnormalities should be assessed at echocardiography.

Presence of Stenosis of the Central or Branch Pulmonary Arteries (Fig. 72.85) Stenosis of pulmonary arteries proximally at the bifurcation or its branches can be associated with supravalvular aortic stenosis, particularly with William’s syndrome. It can be multiple sites along the branches or a generalized hypoplasia. Central pulmonary arteries can be evaluated by echocardiography, but if peripheral branches seems to be involved, other modalities such as spiral CT/MRI will be needed.

Serial Echocardiograms The condition is usually progressive in nature and cases with mild narrowing need careful long-term follow-up.

AORTIC REGURGITATION Congenital aortic insufficiency is a rare entity as an isolated lesion. It frequently occurs in association with

Fig. 72.85: Two-dimensional echocardiography high parasternal short-axis view with color flow mapping, in a 2-year-old child with William’s syndrome, showing bilateral pulmonary artery stenosis with turbulent flow. (LPA: Left pulmonary artery; MPA: Main pulmonary artery; RPA: Right pulmonary artery).

other congenital heart defects, aortic root dilatation, and infectious processes of the aorta. Causes of aortic regurgitation are highlighted in Table 72.12. The primary cardiac abnormalities are the commonest cause of congenital aortic regurgitation such as a bicuspid or quadricuspid aortic valve. Significant aortic regurgitation presenting in neonatal period can be due to two causes: • Aortic–left ventricular tunnel. • Unguarded aortic valve. While evaluating the patient with aortic regurgitation, the following things should be assessed on echocardiography: • Left ventricular outflow abnormality-cause of aortic regurgitation. • Severity of regurgitation. • Left ventricular dimensions—end-systolic and enddiastolic. • Left ventricular systolic and diastolic function.

Left Ventricular Outflow AbnormalityCause of Aortic Regurgitation PLAX view and PSAX view at the level of great vessels are the best views to define the LVOT abnormalities as described


Table 72.12: Causes of Aortic Regurgitation

Primary congenital cardiac abnormality • Aortic valve abnormality – Bicuspid aortic valve – Quadricuspid aortic valve – Absence of aortic valve cusps (unguarded aortic orifice) •

Aortico-left ventricular tunnel (Figs 72.86A and B)

•

Annulo-aortic ectasia (Figs 72.87 A and B).

Connective tissue disorders with aortic root dilatation • Marfan syndrome, Ehlers–Danlos syndrome •

Turner syndrome with aortic ectasia (Figs 72.87A and B)

Association with other forms of congenital heart defects • Aortic valve prolapse into ventricular septal defect (doubly committed, outlet muscular, or perimembranous) •

Dilatation of aortic root as in tetralogy of Fallot physiology

• Truncus arteriosus

1629

severity of regurgitation, ventricular dimensions, and ventricular function is very important before taking the decision about management, whether the patient will require medical follow-up, valve repair, or will need aortic valve replacement. Aortic valve annulus and aortic root size should be measured in patients undergoing aortic valve replacement in PLAX view. If a patient is planned for the Ross procedure, then pulmonary root should be measured in addition to aortic root measurement. Etiology of aortic regurgitation present in other heart defects such as VSD with aortic valve prolapse (commonly doubly committed, outlet muscular, or perimembranous), subaortic stenosis, and truncus arteriosus has been discussed in respective sections.

Aortic Root Dilatation

in an earlier section. Aortic valve cusp number and anatomy, rolled, gnarled, and inadequate, or redundant and prolapsing should be defined. Determination of

Aortic root dilatation occurs in connective tissue disorders like Marfan syndrome, Ehlers–Danlos syndrome, Turner syndrome, and multivalvular heart diseases. With connective tissue disorders, aortic root dilatation is progressive; initially it involves sinuses of Valsalva, ascending aorta, then dilatation progresses to involve aortic annulus leading to distortion of aortic valve, and

A

B

Rheumatic fever (mostly associated with mitral valve disease) Infectious processes of the aortic valve • Bacterial endocarditis

Figs 72.86A and B: Two-dimensional echocardiography. Parasternal long-axis view with slight anterior tilt and color comparison in a 7-day-old neonate with aortico-left ventricular tunnel (arrow). Color flow mapping shows aortic regurgitation. (Ao: Aorta; RV: Right ventricle; LV: Left ventricle; T: Tunnel).

1630


A

B

Figs 72.87A and B: Two-dimensional echocardiography a case of annulo-aortic ectasia in a 2-year-old girl. (A) Parasternal long-axis view showing the dilated (ectatic) aortic root; (B) Subcostal coronal view with anterior tilt showing the left ventricular outflow tract with ectatic aortic root in the same patient. (Ao: Aorta; RV: Right ventricle; LV: Left ventricle; LA: Left atrium).

Table 72.13: Checklist of Aortic Insufficiency in Pediatric Patients

Look for the etiology of aortic valve insufficiency and assess the need for surgical intervention Assess for the following: •

Thickening of the aortic valve cusps

•

Morphology of the commissures, presence of a raphe

•

Cusp prolapse

•

Detached or flail valve cusps

•

Vegetations

• Aortic root dilatation • Left ventricle (LV) wall thickness • LV end-diastolic dimension • LV end-systolic dimension •

LV shortening fraction and LV ejection fraction

aortic regurgitation. While evaluating the patient with connective tissue disorders such as Marfan syndrome, aortic root measurements should be taken at four levels— aortic annulus, sinus of Valsalva, sinotubular junction, and ascending aorta 1 cm above the sinotubular junction, compared with age-related norms and should be followed up serially. Undue dilatation or rapid increase in these parameters will identify the patient who is at a risk of development of aortic dissection and needs elective aortic root replacement procedure.

Severity of Regurgitation With the use of 2D echocardiography, left ventricular dilatation and function can be assessed, and on color flow

mapping and pulsed Doppler interrogation, severity of aortic regurgitation can be evaluated. Parameters of AR are not discussed in detail as these are covered in chapters on acquired heart diseases. A reference checklist is given in Table 72.13.

SINUS OF VALSALVA ANEURYSM (FIGS 72.88A AND B)155–167 Sinus of Valsalva aneurysm is a rare cardiac anomaly. It is thought to result from absence of normal elastic tissue and abnormal development of the bulbus cordis leading to a separation between the aortic media and the annulus fibrosus, which in turn leads to thinning of the wall of the aortic sinus. Other diseases that involves the aortic root may also lead secondarily to the sinus of Valsalva aneurysm. This malformation occurs more frequently in males than females (3:1) and in patients of Asian (India in Asia) origin. It can be congenital or occurs as an acquired lesion in patients with connective tissue disorders such as Marfan syndrome, Ehlers–Danlos syndrome, annuloaortic ectasia, ankylosing spondylitis, or with endocarditis. The weakened wall of sinuses of Valsalva may progressively dilate under systemic pressure and eventually rupture into a low-pressure chamber. Echocardiographic evaluation of aneurysm of sinus of Valsalva includes: • Sinus involved showing characteristic of aneurysm • Presence of obstruction caused by the aneurysm or rupture of the aneurysm


A

1631

B

Figs 72.88A and B: Ruptured sinus of Valsalva in a 30-year-old male patient. (A) Two-dimensional echocardiography with color compare in parasternal short-axis view showing aneurysm of noncoronary sinus rupturing into the right atrium (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

• • •

Cavity where the aneurysm protrudes or ruptures Aortic regurgitation Associated anomalies. Any of the aortic sinuses may be involved, and more than one sinus may be rarely involved (0.6%). Right coronary sinus is most commonly involved (73%), followed by the noncoronary sinus (20%); left coronary sinus (6%) is the least commonly involved. Enlargement of the aneurysm is in the direction of least resistance, so most commonly it bulges into the right-sided chambers. Unruptured aneurysm can cause obstruction of the surrounding structures like the RVOT, right PA and, descending aorta. Tricuspid valve distortion leading to tricuspid regurgitation can occur with aneurysm bulging into RV inflow. Rarely it can burrow into the interventricular septum resulting in complete heart block. The aneurysm can also get calcified. The aneurysm may rupture into a neighboring chamber, leading to development of symptoms acutely. Bulging or rupture of the right sinus can occur into RV (commonest), RA, PA, LV, or into the pericardium. Aneurysm of noncoronary sinus can bulge or rupture into RA (most commonly), RV, LA, LV, or pericardium. Aneurysm of left coronary sinus can extend into LA, RA, LV, RV, PA, or pericardium.

Aortic Regurgitation Aortic regurgitation is a frequent occurrence in patients with an aneurysm of sinus of Valsalva with or without rupture. Aortic regurgitation occurs due to loss of support of the aortic sinus and its annulus and its distortion. In

addition, the runoff produces a Bernoulli’s effect, due to which the cusp is pulled away from its line of apposition leading to increased incompetence. Aortic regurgitation is more common when aneurysm of sinus of Valsalva is associated with VSD (43.3%) as compared to intact ventricular septum (25.9%).

Associated Anomalies Deformation and rupture of the sinus of Valsalva is commonly associated with VSD, so it has to be looked for carefully (Fig. 72.91). The right sinus may prolapse through a doubly committed VSD towards RVOT, causing RVOT obstruction and subsequent rupture. Both the right coronary and noncoronary sinuses may prolapse through a perimembranous VSD into RV inflow, which may lead to distortion of tricuspid valve and tricuspid regurgitation. Other associated anomalies are pulmonary stenosis, TOF, ASD, bicuspid aortic valve, CoA, and LSVC, which needs to be scanned carefully. Aneurysm of sinus of Valsalva can be best defined from parasternal long-axis, subcostal coronal and apical four-chamber views with tilting the transducer toward RV inflow and outflow. PSAX view also defines the anatomy with the sinus protruding into RV inflow, outflow, RA, LA, or into the PA. Combination of 2D echocardiography with color flow mapping and pulsed/continuous wave Doppler interrogation is helpful in detailed profilation of the lesion. With rupture of aneurysm into right-sided chambers, there will be dilatation of right-sided chambers with large left-to-right shunt and rise of pressures. With

1632


rupture of aneurysm into LA or LV, these chambers will be volume-loaded with rise in left atrial and LVEDPs. Color flow mapping demonstrates rupture of aneurysm and the cavity into which it opens. Rupture into RA, LA, RV, or PA will result in continuous flow from aortic sinus to the receiving cavity, while with rupture into LV, there will be only diastolic flow. Color flow mapping also defines the aortic regurgitation. M-mode echocardiography is the best way to demonstrate direction of shunt and its relation to cardiac cycle, with ruptured sinus of Valsalva (RSOV), a continuous flow from aorta to receiving low-pressure chamber can be demonstrated. The measurements of aortic annulus, sinotubular junction, and ascending aorta should be made. Also, the exact sinus involved by the aneurysm and size of its final opening and distance from the coronary orifice should be measured when contemplating RSOV device closure. RSOV aneurysm should be differentiated from aorticocameral tunnel, the most important feature being the origin of tunnel will be above the sinus of Valsalva.

AORTOCAMERAL COMMUNICATIONS168–174 Aortocameral communications are abnormal communications between the root of aorta and one of the cardiac chambers, the commonest being aortico-left ventricular tunnel, followed by aortico-right atrial tunnel, aortico-RV tunnel, and least in frequency is aortico-LA tunnel.

Aortico-Left Ventricular Tunnel (Figs 72.86A and B) Aortico-left ventricular tunnel is a rare congenital malformation characterized by abnormal paravalvular communication between anterior aspect of aorta and LV. It causes progressive left ventricular failure and aneurysmal dilation of aorta. Incidence of aortico-left ventricular tunnel has been estimated to be around 0.1% of congenitally malformed hearts from review of clinical and pathological material and 0.46% of cardiac malformation identified on fetal echocardiography. About twice as many cases have been reported in males as in females, but it is rarely seen in patients of Asian, Oriental, and African descent. Echocardiography in neonate and young infant helps demonstrate the entire course of tunnel as well as its relationship to aortic root, sinuses, and coronary ostia. The PLAX view shows a septal dropout at the anterosuperior part of interventricular septum, with a free

communication noted anteriorly with the RVOT ending distal to right coronary sinus of aorta. In the PSAX view, an echo dropout can be seen at the level of aortic valve. There is a crescent-shaped structure wrapping around the right coronary cusp anteriorly, clearly distinct from aortic root. The aortic origin can be shown to be above the sinus and separate from the origin of both coronary arteries enabling differentiation of tunnel from sinus of Valsalva fistula. Occasionally, a coronary artery may arise from the tunnel. In neonates and infants, it is possible to demonstrate the coronary artery origin on 2D echocardiography; however, in older patients it may be difficult. In apical four-chamber and subcostal coronal views with anterior tilt, the tunnel is seen to protrude into RVOT. Subcostal sagittal view also shows bulging of tunnel into RVOT , which can cause subpulmonary stenosis. Both pulsed Doppler and CFI show systolic antegrade flow and diastolic retrograde flow within the tunnel. CFI is particularly useful in assessing coexisting central aortic regurgitation. Presence of subpulmonary stenosis should also be defined with the use of color flow mapping and pulsed Doppler interrogation. Associated anomalies have been described in several studies and include bicuspid aortic valve, aortic stenosis, PDA, pulmonary stenosis, VSD, and sinus of Valsalva aneurysm. These anomalies can also be demonstrated on 2D echocardiography.

Aortico-Right Ventricle Tunnel Aortico-RV tunnel is another rare congenital malformation in which the tunnel connects aorta above the level of sinus of Valsalva to the RV. PLAX view on 2D echocardiography defines the tunnel as a communication starting above the sinus of Valsalva, and with anterior tilt from this view, opening of this tunnel into RV can be defined. Color flow mapping will reveal high velocity flow into the RV during systole as well as diastole. This needs to be differentiated from RSOV into RV. In RSOV, the aortic end of tunnel is situated below the coronary arteries. RV is usually dilated and hypertrophied, as it is volume- and pressure-loaded.

Aortico-Right Atrial Tunnel Aortico-right atrial tunnel, which connects aorta above the level of sinus of Valsalva to the RA, is very rare. The tunnel, more commonly from left sinus, runs posterior to the aorta and then opens into the RA. PSAX view at the level of great vessels defines the length of tunnel joining RA and aorta. Color flow mapping will show high-velocity, continuous flow from aorta to the RA.


1633

PART 6: ECHOCARDIOGRAPHIC ANATOMY OF TETRALOGY OF FALLOT WITH PULMONARY STENOSIS Prevalence of TOF (regardless of pulmonary valve morphology) ranges from 0.26 to 0.48 per 1,000 live births. TOF consists of anterior and cephalad deviation of the outlet septum leading to a large malaligned (mostly perimembranous type) VSD with narrowing of the RVOT.175–179 Echocardiography is the most important investigation for any such case and has replaced invasive angiography for preoperative evaluation of TOF patients. The evaluation of TOF has to be done in sequential analysis as for any other case of CHD. It is extremely rare to have TOF with isomeric hearts. PLAX view (Figs 72.89A and B) shows the defect well. Subcostal paracoronal view (Fig. 72.90) also identifies the anatomy of the tetralogy well, showing the VSD, infundibular septum, RVOT, and even branch pulmonary arteries, particularly right pulmonary artery (RPA). The important salient features of the lesion are discussed below.

Ventricular Septal Defect

The presence of the large malaligned VSD and dilatation of the aortic root can result in aortic override. This can also be seen with an isolated large VSD without anterocephalad deviation of the outlet septum. Echocardiographically, aortic override is best documented in the PLAX view (Fig. 72.91). The aortic mitral continuity is also best seen in this view.

Commonest VSD seen in 74% of cases of TOF is perimembranous outlet VSD, since the tricuspid valve forms one of the margins of the defect. Echocardiographically, the subcostal sagittal and coronal views show tricuspid– aortic–mitral continuity, which is a differentiating feature from DORV. The aortic valve forms the roof of the defect; the posterior-inferior margin is the area of tricuspid– aortic–mitral continuity and the anterior and anteriorinferior margins are muscular. The PSAX view at the level of the aortic valve shows that the VSD extends from the area of the tricuspid valve anteriorly to the area of the muscular septum (Fig. 72.91). The outlet septum itself separates the aortic valve from the pulmonary valve. Muscular outlet VSD is seen in 20% of cases of TOF. A muscle bar is present in the posterior-inferior margin of the defect and this separates the tricuspid valve from the aortic valve. Thus, except for the superior margin, which is formed by the aortic valve, the VSD in rest of the margins is entirely muscular. Echocardiographically, this feature is well seen in the subcostal coronal view as a bar of muscle separating the aortic valve from the tricuspid valve. In the PSAX view also the aortic valve is separated from the tricuspid valve by a muscle bar. The importance of recognizing this entity is that this bar of tissue separates the conduction tissue from the margins of the defect making the chances of heart block unlikely when the VSD is closed.

A

B

AORTIC OVERRIDE

Figs 72.89A and B: Two-dimensional echocardiography in parasternal long-axis view with color comparison in a 2-year-old child with tetralogy of Fallot showing a large perimembranous ventricular septal defect (VSD), aortic override ( ), and aortic mitral continuity (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1634


Fig. 72.90: A 2-year-old child with tetralogy of Fallot. Two-dimensional echocardiography with subcostal paracoronal view showing the large perimembranous ventricular septal defect (VSD; arrow) with anterior malalignment of the septum, causing subvalvular pulmonary stenosis. (Ao: Aorta; RVOT: Right ventricular outflow tract; RV: Right ventricle).

Fig. 72.91: Two-dimensional echocardiography. Parasternal short-axis view showing a large ventricular septal defect with anterior malalignment of the septum (arrow) leading to subvalvular pulmonary stenosis. (Ao: Aorta; PA: Pulmonary artery; RA: Right atrium; RV: Right ventricle).

In 2 to 3% of the case of TOF, the VSD is juxta-arterial or doubly committed VSD (Figs 72.92 and 72.93).180 The outlet septum is absent and the roof of the VSD is formed by the aortic and pulmonary valve in continuity. The inferior margins are muscular unless the VSD is large enough to extend to the area of tricuspid aortic continuity (i.e. perimembranous). The aortopulmonary continuity in this type of VSD is best visualized in the subcostal paracoronal and PSAX views. Inlet extension of VSD is recognized on echocardiography from the apical four-chamber view. The important echocardiographic features in this case will be dropped out at the level of the AV valve. TOF can also be associated with a complete AVSD. This is differentiated from the inlet extension of a perimembranous VSD by (a) absence of offsetting, (b) presence of a common AV orifice (best visualized in the subcostal sagittal scan, and (c) ASD of the ostium primum variety. Additional VSDs have to be evaluated in any case of TOF (Fig. 72.94). The most common site is in the trabecular septum. Because of the large proximal unrestricted perimembranous VSD and equal right and left ventricular pressures, these smaller defects can be missed even on the color scan unless great care is taken to scan the interventricular septum in detail. The best views to visualize these defects on echocardiography are the subcostal sagittal and the apical four-chamber views. Use of the zoom feature in inverted view of the septum and

low scale of color flow mapping to scan the entire part of the interventricular septum in more detail increases the chances of detecting additional VSDs more reliably. Restrictive VSD (Hoffmann’s variant; Figs 72.95, 72.96, and 72.97): This occurs in 1.5% of the cases of TOF. The hallmark of the VSD in TOF is its unrestrictive nature causing equalization of the right and left ventricular pressures irrespective of the degree of pulmonary stenosis. Very rarely, however, the VSD can become restrictive. The mechanism of the restriction is best recognized echocardiographically. The most common mechanism is the presence of accessory tricuspid valve tissue or the normal tricuspid valve, prolapsing through the VSD, which narrows the interventricular communication.

Pulmonary Stenosis181–185 RVOT narrowing in a case of TOF is a consequence of the anterior and cephalad deviation of the infundibular septum. The hallmark in TOF is infundibular stenosis with variable degree of valvular stenosis (Figs 72.97 and 72.98). Thus, patients with large VSD and isolated valvular stenosis should not be classified under TOF. Anterocephalad deviation of the outlet septum is seen best echocardiographically in the subcostal sagittal, coronal views and PSAX views at the level of the great arteries. In patients of TOF and pulmonary atresia, the deviation is so extreme so as to produce


1635

Fig. 72.92: Two-dimensional echocardiography. Parasternal shortaxis view in a 3-year-old child with tetralogy of Fallot and doubly committed ventricular septal defect showing the point of continuity between aortic and pulmonary valves (arrow). (Ao: Aorta; PA: Pulmonary artery; RV: Right ventricle).

Fig. 72.93: Two-dimensional echocardiography. Parasternal short-axis view in a patient of tetralogy of Fallot with color flow mapping showing doubly committed ventricular septal defect. (Ao: Aorta; PA: Pulmonary artery; RV: Right ventricle).

Fig. 72.94: Two-dimensional echocardiography. Modified parasternal short-axis view in a case of tetralogy of Fallot showing the additional muscular ventricular septal defect (VSD) tract (arrow) with left right shunt. (LV: Left ventricle; RV: Right ventricle).

Fig. 72.95: Tetralogy of Fallot—Hoffman’s variant. Two-dimensional transthoracic parasternal long-axis view with color comparison in a case of tetralogy of Fallot VSD getting partially restricted by the septal leaflet of the tricuspid valve (arrow) leading to suprasystemic right ventricle (RV) pressures with turbulent right-to-left shunt. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

1636


Fig. 72.96: Tetralogy of Fallot—Hoffman’s variant. Parasternal short-axis view with color compare showing large ventricular septal defect getting partially restricted by tricuspid valve leaflet (arrow) with severe infundibular pulmonary stenosis (arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle; RVOT: Right ventricular outflow tract).

A

Fig. 72.97: Two-dimensional echocardiography. Parasternal short-axis view with color compare showing severe infundibular pulmonary stenosis (arrow) in a patient of TOF. (Ao: Aorta; PA: Pulmonary artery; RV: Right ventricle).

B

Figs 72.98A and B: Two-dimensional echocardiography in subcostal paracoronal view with color compare showing severe infundibular pulmonary stenosis (arrow) with turbulent flow in right ventricular outflow tract (RVOT), in a patient with tetralogy of Fallot. (PA: Pulmonary artery; RV: Right ventricle).

Fig. 72.99: Two-dimensional echocardiography in parasternal short-axis view showing short segment pulmonary atresia (arrow) in a patient of TOF. Branch pulmonary arteries are confluent. (Ao: Aorta; LPA: Left pulmonary artery; RPA: Right pulmonary artery; RV: Right ventricle).

atresia (Fig. 72.99). Progression of the obstruction occurs due to (a) failure of the subpulmonary infundibulum to grow with increase in somatic growth, (b) progressive acquired infundibular septal hypertrophy, and (c) progressive acquired RV free wall hypertrophy. All these features can be documented echocardiographically. Pulmonary valve is bicuspid in 51% of cases of TOF.2 Valvular stenosis is almost always present in TOF and is

demonstrable echocardiographically as doming of the pulmonary valve. It is important to measure the annular size in all cases and compare to normal expected for the patient size (Fig. 72.100). Normal pulmonary valve annulus has surgical implications, because the surgeon can correct the abnormality without using a transannular patch. The annular size is best measured in PSAX views or anteriorly tilted long-axis view.


Fig. 72.100: Two-dimensional echocardiography. Parasternal short-axis view showing the measurement of the pulmonary annulus from the hinge points (+) and RCA. (Ao: Aorta; PA: Pulmonary artery; RCA: Right coronary artery (arrow); RV: Right ventricle).

1637

Fig. 72.101: Two-dimensional echocardiography. Modified parasternal short-axis view with color compare in a patient with tetralogy of Fallot showing absence of pulmonary valve (arrow) with hypoplastic pulmonary artery annulus and free pulmonary regurgitation (on color mapping) across the pulmonary annulus. (PA: Pulmonary artery; RV: Right ventricle).

arteries may be dilated to variable degrees. The physiology is essentially same as that of TOF. The RV obstruction is usually at the level of pulmonary annulus; associated infundibular stenosis may sometimes be present. Very rarely, there may be an absence of pulmonary valve in the absence of VSD.

The Pulmonary Arteries (Figs 72.102 to 72.105)

Fig. 72.102: Two-dimensional echocardiography in high parasternal short-axis view showing a narrow origin (arrow) of left pulmonary artery in a case of TOF. (Ao: Aorta; LPA: Left pulmonary artery; MPA: Main pulmonary artery).

Tetralogy of Fallot with Absent Pulmonary Valve (Fig. 72.101) This is a rare variant of TOF seen in 2% of cases. The pulmonary valve is absent and replaced by nubs of fibrous tissue, which is best seen echocardiographically in short-axis views as bright echoes. This is associated with significant pulmonary regurgitation clearly seen on color flow mapping. The main/right/left proximal pulmonary

Echocardiographically, the pulmonary arteries need to be visualized in multiple views. The paracoronal view not only identifies the RVOT, but also well visualizes the right PA. The subcostal coronal view shows the entire length of the right PA from its origin to its branching at the hilum. The PSAX view shows the pulmonary trunk, confluence, and the origins of the right and left pulmonary arteries and a considerable length of the right PA. The left PA, which is most difficult to visualize, is occasionally seen in its entire length from the high left parasternal view and the suprasternal oblique long-axis view with anterior tilt. The suprasternal short-axis view opens the entire length of the right PA. Systematic delineation of the PA anatomy is crucial in the management of TOF. The size of pulmonary arteries is measured at the hila, that is, before the first division. The optimum size of the pulmonary arteries may be seen from the standardized charts for the weight of the baby. Various ratios used for this include: Mc Goons ratio,

1638


A

B

Figs 72.103A and B: Two-dimensional echocardiography with color compare in high parasternal short-axis view showing confluent branch pulmonary arteries with diffuse narrowing in left pulmonary artery (LPA, arrow). (MPA: Main pulmonary artery; RPA: Right pulmonary artery).

Fig. 72.104: Two-dimensional echocardiography in suprasternal short-axis view with anterior tilt showing both the branches of pulmonary artery. (LPA: Left pulmonary artery; RPA: Right pulmonary artery).

Fig. 72.105: Two-dimensional echocardiography in suprasternal short-axis view showing the right pulmonary artery and the adjacent structures. (AO: Aorta; Innom: Innominate vein; LUPV: Left upper pulmonary vein; LA: Left atrium; RUPV: Right upper pulmonary vein; SVC: Superior vena cava).

wherein the ratio of the sum of the size of branch pulmonary arteries to the descending aorta is measured. This should exceed 1.5 for optimum outcome. The pulmonary arteries in TOF frequently show abnormalities of size, confluence, or obstruction. The most important step is to determine whether the pulmonary arteries are confluent. Once this is done, the individual pulmonary arteries are scanned to look for narrowing. Narrowing can be of two varieties: (a) discrete stenosis and (b) diffuse hypoplasia. The common sites for discrete stenosis are (a) the point of bifurcation of the main PA, thus involving the origin of the right

and left PA, (b) the site of insertion of the patent ductus arteriosus into the left PA, and (c) supravalvular narrowing of the main PA. Diffuse hypoplasia can involve the left or right pulmonary arteries or both. Multiple, peripheral PA narrowing within the lung parenchyma is very rare and cannot be detected by echocardiographic scans.

Aortic Arch The suprasternal view is used to differentiate left and right aortic arches. Right aortic arch is seen in 25% of patients


with TOF (Fig. 72.106). Two methods are used for their differentiation: (a) In the suprasternal short-axis view, the transducer is tilted posteriorly. In right aortic arch, the descending aorta mostly falls to the right and in left aortic arch the descending aorta mostly falls to the left. (b) The branching pattern of the head and neck vessels is most important. In left aortic arch, the normal branching pattern of the first branch of the aortic arch (innominate artery) can be seen dividing into two branches to the right. The opposite is true in patients with right aortic arch with mirror image branching. The fallacy of the second method is when patients of right arch have an aberrant left subclavian (3%) artery and vice versa (<1%). (c) The

Fig. 72.106: Two-dimensional echocardiogram in suprasternal view showing right aortic arch in a patient with tetralogy of Fallot showing the division of the first branch toward left side. (LSA: Left subclavian artery; LICA: Left internal carotid artery).

A

1639

relationship of trachea and the ascending aorta in this view also helps in deciding the side of the arch. The ascending aorta is to the left of the trachea in left-sided and on the right side in right-sided aortic arch.

Patent Arterial Duct and Aortopulmonary Collaterals (Figs 72.107A and B) Patent arterial duct is easily defined with color Doppler flow as continuous flow in the left PA at its origin. The duct originates from its usual position in patients with TOF with pulmonary stenosis. In patients with pulmonary atresia, however, the duct is “vertical”, that is, it arises from the under surface of the arch and descends down, and then takes a tortuous S-shaped course before joining the left PA. Echocardiographically, patent arterial ducts in TOF with pulmonary stenosis are best seen from the high parasternal views (ductal view), whereas the vertical ducts are best seen in the suprasternal long-axis views. Right-sided duct can rarely be seen in patients with TOF. In such cases, the continuous flow on color flow mapping is seen in the right PA. Aortopulmonary collaterals are most often present in cases of TOF with pulmonary atresia, although they can be present in patients with TOF with pulmonary stenosis. The suprasternal views show the collaterals arising from aortic arch or descending aorta on color Doppler mapping using a low scale as continuous turbulant signal. The presence of collaterals can also be suspected by profiling the descending thoracic aorta in its long axis from subcostal

B

Figs 72.107A and B: Two-dimensional echocardiography. (A) Suprasternal long-axis view showing the origin of a collateral from the ductal area (arrow); (B) Subcostal sagittal view showing collaterals arising from the descending aorta (arrow). (Des Ao: Descending aorta; TA: Transverse arch).

1640


window on color flow mapping with a low scale. It is usually not possible to further delineate the course of these collaterals in the lung parenchyma by echocardiography.

Coronary Artery Anomalies186 Surgically important coronary artery anomalies are seen in 3 to 15% of patients with TOF. The PSAX view is the best to detect these anomalies. Because of the clockwise rotation of the aortic root, the right coronary sinus occupies a more leftward and anterior location, and left sinus becomes more posterior. The origin of the right and left coronary arteries from these sinuses can be seen clearly in PSAX view. Thus, in patients with normal origin of coronary arteries, the left main stem is seen to course from a more left/posterior location and the right main stem from a more leftward position. The most common anomalies seen are: (a) origin of the LAD coronary artery from the RCA. In the PSAX view, this is seen as a large branch arising from the RCA and coursing leftward and anterior toward the RVOT. A large coronal branch can also be mistaken for the LAD. However, in such cases the LAD is seen arising from the left main branch. (b) Single coronary artery arises from the right sinus or left sinus, and (c) dual LADs arise from the left and the right sinuses. In this condition, it may be difficult echocardiographically to differentiate the branch arising from the right main stem from a large coronal branch.

Echocardiographic Measurements in Tetralogy of Fallot1,2,187

left to right (pink tetralogy). However, the major advantage of the color Doppler is in the evaluation of small additional muscular VSD. In nearly all patients of TOF, the VSD does not reveal any gradients because of equal right and left ventricular pressures. The only exception is in patients in whom the VSD becomes restrictive. The gradients then will be determined by the severity of the pulmonary stenosis. If the pulmonary stenosis is severe, then there would be reverse gradients (from RV to LV) because of suprasystemic RV pressures. Evaluation of pulmonary stenosis (Fig. 72.108): It is difficult to differentiate by Doppler, the relative contribution of the infundibular, valvular, supravalvular, and peripheral pulmonary component of the obstruction. It is also difficult to align the Doppler signal in order to obtain the total gradient across the RVOT and pulmonary valve because of their different spatial orientation. Subcostal sagittal view of RV outflow is the only view that opens both the RVOT and pulmonary valve, and in some patients one may be able to align the Doppler signal accurately. It is important to determine whether the pulmonary circulation is protected from the high RV pressures. Color flow mapping shows that the turbulence starts at the subvalvular level and continues to the PA level. Again, color flow fails to differentiate the relative contribution of the various levels of obstruction in TOF. Poor echocardiographic window, very severe infundibular obstruction, and severe polycythemia are some causes of inability to document antegrade flow across the RV outflow by color or pulsed Doppler accurately.

The following measurements are routinely performed and compared to a nomogram based on weight of the patient. • The pulmonary annulus—This is measured at the site of insertion of the pulmonary valve leaflets. • The right and left PA at the hilum just before their first branching—The suprasternal short-axis view is selected for measuring the right PA and the high parasternal or the oblique suprasternal long-axis views for the left PA.

The Utility of Doppler in Evaluation of Patients of Tetralogy of Fallot Evaluation of ventricular septal defect: Ventricular septal defect (VSD) is usually seen to shunt right to left. If the pulmonary stenosis is mild to moderate, the VSD shunts

Fig. 72.108: Continuous wave Doppler signal showing right ventricular outflow gradient in a case of tetralogy of Fallot (TOF). Note the sickle-shaped signal of the infundibulum stenosis (arrow).


Patent arterial duct and aortopulmonary collaterals: These are seen as continuous signals in the PA on color flow mapping. Pulsed Doppler shows continuous high velocity signals on the spectral waveform. The PDA is seen opening at the junction of the main PA, left or rarely right PA. Aortopulmonary collaterals usually open more distally beyond the hilum into the PA. Aortic regurgitation (Fig. 72.109): It is common to see mild aortic regurgitation in TOF, especially in adolescents, adults, and patients who had undergone shunt surgery or have had endocarditis. Associated anomalies include presence of ASD in 38% and LSVC in 9% of cases of TOF. One should keenly look for pulmonary venous anomalies particularly on 2D echocardiography, because with decreased pulmonary blood flow conditions, the pulmonary veins may not be well visualized on color flow mapping. Aortopulmonary window (APW) (Fig. 72.110), LVOT obstruction, mitral valve anomalies (Fig. 72.111), have been reported, but these left-sided lesions are very rare in TOF patients.

1641

example, anomalous origin of one of the PAS from the ascending aorta may also need additional imaging modalities. In older children, adolescents, and adults with TOF, inability to delineate anatomical details is an indication for using other imaging modalities like angiography MRI/CT. They are also indicated in evaluation of patients for complete repair of TOF following shunt surgery for accurate delineation of the PA anatomy and determination of PA pressure. It is difficult to predict the PA pressure accurately by Doppler even if the signals are good. In the immediate postoperative state, cardiac catheterization is indicated for accurate delineation of the severity and extent of peripheral PA stenosis, residual VSD, and for coil occlusion of aortopulmonary collaterals.

Postoperative Evaluation of Tetralogy of Fallot

In neonates and infants, the suspicion of major aortopulmonary collaterals (MAPCAs) and discontinuous pulmonary arteries forms the most important indication for cardiac catheterization. Rarer variations of TOF, for

The postoperative evaluation of a case of TOF includes evaluation for the residual lesions such as residual RVOT obstruction (Fig. 72.112), branch PA stenosis, and residual VSD (Fig. 72.113). Branch PA stenosis is particularly common at the site of ductal insertion or at the site of previous BT shunt. It is important to take tricuspid regurgitation jet velocities to determine the RV pressure, as it would reflect any obstructive component in both RVOT and branch pulmonary arteries.

Fig. 72.109: Two-dimensional echocardiography in parasternal long-axis view with color flow mapping showing moderate aortic regurgitation and dilated aortic root in a case of grown up tetralogy of Fallot. (AO: Aorta; LV: Left ventricle; RV: Right ventricle). (*), perimembranous ventricular septal defect (VSD).

Fig. 72.110: Two-dimensional echocardiography in parasternal short-axis view at the level of the aorta, profiling a large aortopulmonary window (arrow) in a neonate with pulmonary atresia and ventricular septal defect. (Ao: Aorta; PA: Pulmonary artery; valvular pulmonary atresia).

Indications for Cardiac Catheterization in Patients with Tetralogy of Fallot

1642


Fig. 72.111: Two-dimensional echocardiography in parasternal long-axis view in a case of tetralogy of Fallot showing a large ventricular septal defect with overriding aorta. Mitral valve is thickened and doming is present consistent with mitral stenosis. Also note the presence of short mitral chordae. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

A

Fig. 72.112: Two-dimensional echocardiography with color flow mapping in a patient with tetralogy of Fallot following surgery. Parasternal long-axis view with anterior tilt shows significant turbulence in right ventricular outflow tract. (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

B

Figs 72.113A and B: Two-dimensional echocardiography in parasternal long-axis view with color flow mapping in cases of tetralogy of Fallot after total correction showing significant residual ventricular septal defect (VSD) from the upper end of the VSD patch (VSD patch marked by the arrow). (Ao: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle).

Small residual VSD may be seen in the region of the patch at the site where the sutures are placed far apart to avoid damage to the AV node and the conduction system. As endothelium grows over the patch, these shunts usually disappear generally by the third month, and rarely they may be significant (Figs 72.113A and B). Other types of shunt that may be seen in postoperative patients include small insignificant coronary artery fistulas. Significant pulmonary regurgitation may be present in a subset of patients where a transannular patch has been sutured. This leads to progressive RV dilatation and in some cases, aneurysm of RVOT (Figs 72.114 and 72.115). This needs

to be carefully evaluated in the follow-up of this subset of patients. Another most important aspect to evaluate is the RV function, both systolic and diastolic (Figs 72.116 to 72.119), which needs to be monitored at each follow-up visit. The presence of pulmonary regurgitation leads to progressive dilatation of the right sided structures: RVOT, right ventricle and right atrium, hence one needs to look keenly at the RV function parameters (Figs 72.114 and 72.115). Systolic function may be measured by TAPSE (tricuspid annular systolic excursion (Fig. 72.117), RV fractional area change (Figs 72.118A and B) and systolic indices on tissue Doppler (Fig. 72.116).


1643

Fig. 72.114: Two-dimensional echocardiography. Apical fourchamber view in a patient with tetralogy of Fallot with transannular patch showing dilatation of the right atrial (RA) and right ventricular (RV) cavity. (LA: Left atrium; LV: Left ventricle).

Fig. 72.115: Two-dimensional echocardiography with parasternal short-axis view in an operated patient with tetralogy of Fallot. A transannular patch is placed across the right ventricular outflow tract. There is dilatation of the right ventricular outflow tract, right. (PA: Pulmonary artery; RVOT: Right ventricular outflow tract; RA: Right atrium; RV: Right ventricle).

Fig. 72.116: Tissue Doppler velocity of the annulus of the tricuspid valve showing normal systolic velocity.

Fig. 72.117: TAPSE: tricuspid annular systolic excursion is a measurement of the systolic function of the right ventricle. The M-mode cursor is placed at the annular attachment of the anterior septal leaflet.

Evaluation of the diastolic dysfunction must be done in any postoperative patient of TOF as the diastolic dysfunction may be present even in the absence of systolic dysfunction. Various parameters to assess the right ventricular diastolic dysfunction include: (A) Inflow parameters: Diastolic dysfunction can be measured by measuring isovolumic relaxation time, deceleration time, E and A wave velocities and EA ratio; (B) Inferior vena cava (IVC) : Normally there should be more than 50% collapse of IVC with inspiration. With diastolic dysfunction IVC becomes dilated with decreased respiratory variation.

With diastolic dysfunction there is resistance to right ventricular filling which exceeds pulmonary vascular resistance, this leads to transmission of the transtricuspid atrial flow to pulmonary artery, superior, inferior vena cava and hepatic veins; (C) Flow reversal in hepatic veins and SVC can be documented with Doppler signal.Reversal in SVC is best interrogated from subxiphoid sagittal view or suprasternal short-axis view; (D) Transmitted a wave in main pulmonary artery: In parasternal short-axis view the Doppler cursor is placed in main pulmonary artery. The presence of “a” wave following “p” wave on ECG and

1644


A

B

Figs 72.118A and B: Right ventricle (RV) fractional area and fractional area change. Measuring the right ventricular area in diastole (RVD) (A) and subtracting from it the right ventricular area in systole (RVS); (B) The difference divided by the right ventricle area in diastole gives the fractional area change, a measure of the right ventricular systolic function.

A

B

Figs 72.119A and B: Right ventricular diastolic dysfunction. Showing the profiling of inferior vena cava (IVC) from subcostal window: (A) IVC is dilated; (B) M-mode cursor across the IVC shows no respiratory phasic variation.

present during all phases of respiration characterizes atrial flow transmission to pulmonary artery; (E) Tissue Doppler diastolic parameters with cursor placed across the tricuspid valve.

DOUBLE OUTLET RIGHT VENTRICLE Double outlet right ventricle (DORV) encompasses features of various entities, ranging from simple VSD to TOF to transposition of the great arteries (TGA). This is a rare anomaly. Its frequency is approximately 0.09 cases per 1,000 births, and it represents 1 to 1.5% of patients with

CHD. Like the varied spectrum of DORV, the definition is also variable.188,189 The commonest definition by Neufield et al.188 is as follows: Both great arteries and arterial trunks arise exclusively from the morphological RV, neither semilunar valve is in fibrous continuity with either AV valve, and usually, a VSD is present and represents the only outlet from the LV. Pulmonary valve or subpulmonary stenosis may be present or absent. Echocardiography has a very important role in delineation of cardiac anatomy to enable planning of surgical strategy for DORV. DORV often occurs in association with a variety of complex situations that include atresia of one of the atrioventricular valves and


1645

Classification and Terminology190–195 The determinants of individual subtypes of DORV are based upon the location of the VSD and great artery relationship.

Location of the Ventricular Septal Defect in Relation to the Great Arteries The location of the VSD determines whether it can be routed to either of the two great vessels.

Subaortic (Fig. 72.120) Fig. 72.120: A 5-year-old case of double outlet right ventricle (DORV) with ventricular septal defect (VSD) and pulmonary stenosis. Two-dimensional echocardiography in parasternal longaxis view shows the mitral aortic large subaortic VSD, more than 50% aortic over ride discontinuity. (Ao: Aorta; LV: Left ventricle; RV: Right ventricle).

discordant atrioventricular connection. For this section, we will confine ourselves to DORV in association with two functioning atrioventricular valves and atrioventricular concordance.

Definition The diagnosis of DORV (Fig. 72.120) requires the following criteria to be fulfilled.188–193 DORV infers that both great arteries arise from the RV as the name implies. There is a spectrum of the degree of override of one great vessel and herein lies the controversy as to when to classify an origin as double outlet versus concordant ventriculoarterial connection. Some authors follow the 50% rule, which means that if a vessel is 50% or more committed to a chamber, it is considered originating from that chamber. However, it is difficult to determine when exactly an override is 50% or more. To avoid this difficulty, some authors diagnose DORV if the override is 90% or more. Some consider absence of fibrous continuity between the posterior semilunar valve and the mitral valve (Fig. 72.120A). According to some, this is not mandatory. One can have fibrous continuity of the mitral and one semilunar valve with criteria of origin of great vessel being fulfilled. We believe that both features are important for the diagnosis of DORV, that is, more than 50% override and mitral aortic discontinuity.

The VSD is located just below the aortic conus and thus can be routed to aorta. In this case, saturations are better because saturated blood from LV is directed to the aorta. In the event that the great artery relationship is normal with no pulmonary stenosis, the condition may be corrected like a perimembranous VSD. In presence of pulmonary stenosis, it can be repaired like a TOF. In the majority of cases in this group great vessels are normally related. In rare cases, the aorta may be L-malposed.

Subpulmonic (Fig. 72.121) The VSD is located just below the subpulmonic conus and thus can be routed to PA. In the majority of cases in this group the aorta is malposed (i.e. anterior to the PA). Pulmonary arteries are often not “protected” by stenosis of the valve or subvalvular region. These patients present like classical transposition-Taussing Bing Anomaly. However, pulmonic stenosis may occur if the conal septum between the aortic and pulmonary roots is deviated posteriorly and/or to the left.

Doubly committed Here, the conal septum between the aortic and pulmonary outflow tract is deficient. As a result, the VSD is located below both outflow tracts and can be routed to either great vessel.

Remote Remote VSDs are typically located in the inlet septum (Fig. 72.122). The tricuspid valve tensor apparatus comes in the path between the VSD and either of the outflow tracts. Overriding/straddling of tricuspid valve can occur

1646


Fig. 72.121: Two-dimensional echocardiography. Subcostal view with anterior tilt showing both great vessels arising from right ventricle (RV). Subpulmonary ventricular septal defect (VSD) is routable to the pulmonary artery (arrow). (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

A

Fig. 72.122: Two-dimensional echocardiography. Apical fourchamber view in a case of double outlet right ventricle (DORV) showing large inlet ventricular septal defect (VSD). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

B

Figs 72.123A and B: Two-dimensional echocardiography in a subxiphoid sagittal view in two cases, showing a ventricular septal defect located in the inlet septum (arrow) and not related to either great artery origin. (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV": Right ventricle).

in this type of VSD. This group also includes muscular VSDs that cannot be routed to either great vessel (Figs 72.123A and B).

Great Artery Relationship to one Another The following four possibilities exist in DORV: • Normal great artery relation • Side-by-side great artery relationship

• •

D-malposition of the aorta L-malposition of the aorta. Various combinations with the above give rise to 16 individual subtypes with 9 being commonly reported. Additional descriptive features should include the state of the outflow tracts to each great artery and associated anomalies. The echocardiographic description should include a statement on whether or not a two-ventricle repair is feasible.


Establishing a Diagnosis of Double Outlet Right Ventricle by Echocardiography194 The following needs to be specifically evaluated: • VSD • Subpulmonary outflow tract • Subaortic outflow tract and arch • Coronary arteries.

Subaortic Ventricular Septal Defect In the subcostal sagittal view, the aorta will be seen to arise predominantly from RV. In this view, the tricuspid valve is seen to form the posteroinferior margin. Its attachments can be variable. In some cases, some chordae can gain attachment to the outlet septum. The subpulmonary outflow tract will not be seen in this view as it is more anterior. This view also shows the size of the VSD (discussed later). In the subcostal coronal view, both great vessels can be seen arising from the RV, with the subpulmonary outflow tract anterior and to the left of the aortic outflow like in TOF. The PLAX and apical five-chamber views also clearly demonstrate the degree of override of aorta like in tetralogy as well as aortic mitral discontinuity.

1647

pulmonary annulus is commonly associated, and to a varying degree, hypoplasia of the pulmonary trunk. Echocardiographically, malalignment of outlet septum is recognized by subcostal sagittal or coronal views. Apical five-chamber and PLAX views show malalignment of outlet septum very well in the group of patients with transposed great vessels. By Doppler echocardiography, the severity of pulmonary stenosis is best assessed in the subcostal coronal view in the patients with normally related vessels and in the apical views in those with d-malposed great vessels.

Aortic Outflow Obstruction Stenosis of the subaortic region may result from anterior malalignment of the conal septum. This is seen in the group of patients with malposed great vessels. They rarely produce any Doppler gradients. Typically, the aortic annulus, ascending and transverse arches are smaller than normal, and coarctation is a common association. The following measurements are important: aortic annulus, ascending aorta, transverse arch, distal transverse arch, aortic isthmus, and the narrowest dimension of the coarctation site if present.

Subpulmonary Ventricular Septal Defect (Taussig–Bing Anomaly) In this condition, the aorta is anterior (malposed) in majority of cases. In the subcostal sagittal view, the great vessel overriding the septum is the PA. The aorta will not be seen or will come under view in a more rightward sweep. In the coronal section, both great vessels will be seen having a parallel origin with the aorta to the right and PA to the left. Pulmonary valve and mitral valve discontinuity will also be obvious.

Stenosis of the Pulmonary Outflow The commonest cause of obstruction is malalignment of outlet septum. In normally related great vessels the outlet septum is anteriorly malaligned and in transposed great vessels the outlet septum is posteriorly malaligned, resulting in subpulmonary stenosis. Hypoplasia of

Fig. 72.124: Two-dimensional echocardiogram from subcostal short-axis view with color compare showing restricted subaortic ventricular septal defect (VSD) in a case of double outlet right ventricle (DORV). VSD size is smaller (small white arrows) than the aortic annulus (block yellow arrows) and routing will require VSD enlargement. Tricuspid valve () does not come in the pathway from the left ventricle to aorta.

1648


Table 72.14: The Complete Checklist for Preoperative Assessment of Double Outlet Right Ventricle

Visceral and atrial situs, sequential chamber relationship Systemic and pulmonary veins, atria and atrial septum Atrioventricular valve morphology, attachments of the valve tissue and function The ventricles: size and function The ventricular septum: location of ventricular septal defects, size of the ventricular septal defect as compared to the aortic annulus, “routability” of ventricular septal defect, presence or absence of atrioventricular valve tissue in the way between the ventricular septal defect and the great artery (at the site of the prospective patch), presence or absence of conal tissue that may obstruct the prospective patch (which may therefore require resection) The conotruncus: This includes the outflow tracts that lead to the great vessels and the great vessel origins including the semilunar valves; the presence or absence of obstruction in either of the outflow tracts, the nature of obstruction if present, the severity of obstruction; and the sizes of the aortic and pulmonary valve annuli The status of the branch pulmonary arteries The presence or absence of patent ductus arteriosus The aortic arch: side, branching, and the presence or absence of coarctation Feasibility of a two-ventricle repair (with reasons) Likelihood for requirement of a conduit Coronary artery anatomy

Restriction of the Ventricular Septal Defect (Fig. 72.124) Mild restriction in size of VSD is quite common but rarely severe to produce a Doppler gradient across the VSD (between left and RV). VSD is defined as small when its size is smaller than the aortic annulus.

Remote Ventricular Septal Defect One should suspect a remote VSD if while visualizing the great vessels, the VSD is not seen. Inlet VSDs are best seen in the subcostal views in a more posterior plane along with the tricuspid valve. In the apical 4C view, the VSD is seen in the plane that visualizes the mitral and tricuspid valves (crux). In this view, as one sweeps anteriorly toward the great vessels, the VSD disappears from view. Overriding and straddling of tricuspid valve can be well visualized in this view.

Role of Echocardiography in Planning Surgical Strategy (Table 72.14)195–198 The aim of evaluation is to ensure that a two-ventricle repair is carried out if and when possible. Both the long-term survival and functional status after two-ventricle repair are superior to patients who undergo the single ventricle repair.196–198 Two good-sized ventricles: Hypoplasia of either of the ventricles clearly rules out a two-ventricle repair (Fig. 72.130). In borderline situations, the size of the

mitral or tricuspid valve annulus should be determined and compared to normal. A size of < 2 standard deviations of either of the annuli merits concern. • Straddling of either of the AV valves (Fig. 72.125). Typically, straddling of the tricuspid valve is associated with an inlet defect and/or hypoplasia of the RV. Straddling of the mitral valve may occur in patients with outlet VSD • Confluent adequate-sized pulmonary arteries: Measurements of pulmonary annulus, pulmonary trunk, and branch pulmonary arteries should be made like in TOF • The VSD should be suitably located for intraventricular re-routing. If pulmonic stenosis is present, the VSD will be routable to the aortic root without AV valve tissue in the way. In the absence of pulmonic stenosis, the VSD should be routable to either the aorta or the PA. This is where echocardiography provides critical information that is often not available even on angiography • Atrioventricular valve tissue in the way between VSD and the aorta (Figs 72.126 and 72.127; or PA in the case of a Taussig–Bing anomaly). Careful subxiphoid and PSAX sweeps help in evaluating the location of the prospective baffle and whether the AV valves will come in the way • Inlet VSD is not an absolute contraindication for twoventricle repair. It is possible to route remotely located VSDs with tricuspid valve tissue in the way using innovative surgical methods such as the multiple patch technique. If the patient is a candidate for two-ventricle repair, additional specific issues need to be addressed. They include:


Fig. 72.125: Two-dimensional echocardiography. Subcostal sagittal view in a case of situs inversus with mesocardia showing a large ventricular septal defect with hypoplasia of the right-sided left ventricle. (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

A

1649

Fig. 72.126: Two-dimensional echocardiography in subcostal coronal view with anterior tilt in a case of double outlet right ventricle, ventricular septal defect (VSD), and pulmonary stenosis. Note the presence of tricuspid valve tissue in the pathway from left ventricle (LV) to aorta (arrow). (Ao: Aorta; LV: Left ventricle; RV: Right ventricle).

B

Fig. 72.127: Two-dimensional echocardiogram. Subcostal short-axis view with anterior tilt and color compare in a case of double outlet right ventricle (DORV) with a large subaortic ventricular septal defect (VSD) and pulmonary stenosis. Presence of tricuspid valve (arrow) in the pathway from left ventricle (LV) to aorta resulting in restriction of the VSD. (Ao: Aorta; LV: Left ventricle; RV: Right ventricle).

•

Origin of LAD coronary artery in the TOF type of DORV (with subaortic VSD and normally related great arteries). If the LAD coronary artery is seen to cross in front of the RVOT, a conduit or a modified technique for relieving RV obstruction may be required. The origin of coronary arteries in the Taussig–Bing anomaly prior to an arterial switch operation. • The incidence of atypical coronary artery origin is higher in the Tausig–Bing anomaly as compared with classical transposition • Presence or absence of additional muscular VSDs that may require to be closed at the time of surgery should be looked for

•

Other associated anomalies that may need to be addressed need proper evaluation. The postoperative evaluation of such cases is essentially the same as that described under TOF repair. Postoperative evaluation involves: • Checking for residual lesions: residual VSD, additional VSD • Checking for pulmonary stenosis and RVOT gradient (or RV–PA conduit gradient; Fig. 72.128). The gradient across RVOT may be aligned in the subcostal sagittal view with anterior tilt and in paracoronal and PSAX views. Tricuspid regurgitation velocity may give a good indication of the presence of distal obstruction

1650 • • • •

•


Evaluation of branch pulmonary arteries Looking for RV systolic and diastolic function (as explained earlier) Looking for the presence of LVOT gradients (generally across the VSD) In case of BT shunt, evaluate the patency of the BT shunt (Figs 72.129 and 72.130) and look for distortion of the pulmonary arteries In case of a PA band, estimate the band gradients to decide the adequacy of the band and PA pressures. One should also look for migration of PA band and distortion of pulmonary artery branches.

Fig. 72.128: Two-dimensional echocardiogram in parasternal short-axis view with color flow mapping in an operated patient with pulmonary atresia and ventricular septal defect (VSD) showing conduit obstruction (arrow). (Ao: Aorta; RV: Right ventricle).

A

TRUNCUS ARTERIOSUS (FIGS 72.128, 72.131 TO 72.134) A common arterial trunk arising from the base of the heart, and giving origin to aorta, pulmonary arteries, and coronaries is referred to as truncus arteriosus. A single semilunar valve is found in truncus arteriosus, and this valve differentiates truncus arteriosus from aortic and pulmonary valve atresia, conditions in which a single arterial vessel also receives the entire output of both ventricles but in which a second atretic semilunar valve is present. Truncus arteriosus is usually associated with a large VSD resulting from absent or deficient outlet septum. In 25% of cases, the defect may extend to the membranous/ perimembranous area. Rarely, the VSD may be restrictive or even absent. According to the initial classification given by Collet and Edwards199 in 1948, truncus may be classified as following: Type I: Origin of a main pulmonary trunk from the lateral aspect of the common trunk. Type II: Left and right pulmonary arteries originate separately from the common trunk. The origin is close to each other, or from a common orifice, usually located on the posterior aspect of the common trunk. Type III: Origin of only one PA from the common trunk, the other PA can originate from the ductus arteriosus or directly from ascending aorta (MAPCA artery). Type IV: It is defined not by the pattern of origin of pulmonary arterial branch but rather by the coexistence of an interrupted aortic arch or aortic hypoplasia or preductal aortic coarctation.

B

Figs 72.129A and B: Two-dimensional echocardiography. Suprasternal short-axis view showing a patent left BT shunt (arrow) to left pulmonary artery. (LPA: Left pulmonary artery); (B) Color Doppler flow mapping in the same patient showing flow through the left BT shunt indicating its patency.


1651

Fig. 72.130: Two-dimensional echocardiography with color flow mapping suprasternal short-axis view showing the right BT shunt (arrow) to right pulmonary artery. (RPA: Right pulmonary artery).

A

B

C

Figs 72.131A to C: Two-dimensional echocardiography. (A) Subcostal coronal view with anterior tilt in a child with truncus arteriosus Type I, giving rise to aorta and pulmonary artery (arrow) showing the presence of single outflow truncus (Tr) overriding the ventricular septal defect (marked by star); (B) Parasternal long axis view showing the presence of single outflow truncus (Tr) with main pulmonary artery stump arising from the truncus ( arrow); (C) Parasternal short axis view with color flow mapping in the same patient showing the common trunk (MPA) giving rise to both the pulmonary arteries). (RV: Right ventricle; LV: Left ventricle; Tr: Single outflow truncus; Ao : Aorta).

In these cases, a well-documented correlation with 22q11 deletion syndrome is noted. Van Praagh and van Praagh have proposed an expanded classification system that also includes two commonly associated abnormalities of the great arteries.

Type A signified the presence of VSD while type B signified the absence of VSD. Their type A1 corresponds to Type I of Collett and Edwards, and type A2 encompasses Types II and III. Type A3 includes cases with absence of truncal origin of one PA, with blood supply to that lung from the

1652


Fig. 72.132: Two-dimensional echocardiography. Parasternal short-axis view from an infant with persistent truncus arteriosus showing tricuspid truncal valve. (LA: Left atrium; RA: Right atrium; T: Truncal valve).

A

Fig. 72.133: Two-dimensional echocardiography. Subcostal coronal view with anterior tilt showing the origin of the main pulmonary artery from the lateral aspect of the common trunk (arrow). There is flow acceleration in the main pulmonary artery consistent with flow restriction. (PA: Main pulmonary artery trunk; TR: Truncus; Ao: Aorta).

B

Figs 72.134A and B: Two-dimensional echocardiography in high parasternal short-axis view with color compare in a case of persistent truncus arteriosus type I with confluent branch pulmonary arteries. (LPA: Left pulmonary artery; RPA: Right pulmonary artery; T: Truncal valve).

ductus arteriosus or from a collateral artery. Lastly, type A4 is associated with underdevelopment of the aortic arch, including tubular hypoplasia, discrete coarctation, or complete interruption.200 Modified Van Praaghs classification was accepted by Congenital Heart Surgery Nomenclature Database Project 2000 and classified into type A1-2, type A3( hemitruncus) and type A4. Dr Anderson et al. proposed a simplified classification classifying truncus into Aortic dominant type and pulmonary dominant type.

Echocardiography (Figs 72.131 to 72.134) Intracardiac anatomy usually reveals situs solitus and AV concordance. Two balanced ventricles are usually present and separated by a large VSD. Truncus arteriosus has been described with tricuspid atresia, hypoplastic double inlet ventricle, and a very rare form with discordant AV connection.


Two-Dimensional Echocardiography201 Subcostal coronal view with anterior tilt shows a common trunk arising from the heart, and overriding the VSD. Subcostal paracoronal view can profile the pulmonary artery arising from the trunk and bifurcating into right pulmonary artery and left pulmonary artery from lateral aspect of the trunk. Apical four-chamber view with anterior tilt will profile the common trunk arising from the heart and overriding the VSD. PLAX view is the best view to profile truncal anatomy. This view shows the common trunk arising from the heart committed to both ventricles and overriding the large VSD. Slight posterior tilt from a standard PLAX view shows the origin of main PA from the posterolateral aspect of the common trunk. PSAX view at the base of heart shows the truncal valve in cross section, large outlet VSD, and pulmonary arteries as they arise

1653

from the trunk. Truncal valve can be tricuspid (60–67%), quadricuspid (25–31%), or bicuspid (8%). Valve leaflets are usually thickened. The truncal valve is in continuity with the anterior mitral valve leaflet in the PLAX view. The truncal valve may be normal, stenotic, and/or regurgitant. Rarely, there can be absence of the pulmonary arteries. From suprasternal view, the aortic arch anatomy should be properly defined to ascertain the side of arch (right aortic arch is reported in 25–36% of cases), branching pattern, and associated coarctation or arch interruption.

Doppler Imaging Color flow Doppler mapping shows regurgitation or stenosis of truncal valve and any stenosis at the origin of pulmonary arteries. With continuous wave Doppler, gradient across the truncal valve and pulmonary arteries can be recorded.

PART 7: COMPLETE TRANSPOSITION OF GREAT ARTERIES TRANSPOSITION OF GREAT VESSELS (TGA)

Anatomy

TGA means discordant ventriculoarterial connection, that is, origin of great vessels from inappropriate ventricles. TGA accounts for 5–7% of all congenital cardiac malformations. Aorta arises from morphological RV and pulmonary arteries from the morphological LV. It is not based on the spatial interrelationship of the great arteries.202–204

Among the characteristic features generally recognized on echocardiography is the parallel orientation of ventricular outflows (both the PA and the aorta) unlike normal hearts where they cross (Figs 72.135A and B). The pulmonary valve is not wedged as deeply between the two atrioventricular valves as is the aortic valve in the normal heart. The area of offsetting of atrioventricular valves and

A

B

Figs 72.135A and B: Two-dimensional echocardiography with color compare in parasternal long-axis view with anterior tilt in a neonate with complete transposition of great vessels (TGA) showing ventriculoarterial discordance and the presence of parallel great vessels. There is acute posterior angulation of the pulmonary artery as it arises from the left ventricle. (LV: Left ventricle; RV: Right ventricle; Ao: Aorta; PA: Pulmonary artery).

1654


perimembranous septum is less marked. LVOT is longer than in a normal heart but not to the extent of AV canal defect. In about 40 to 45% of cases there is an associated VSD. The entire ventricular septum is a straight structure rather than curved as in the normal heart.204,205 In the normal heart, aortic root is right and posterior to pulmonary trunk with situs solitus and left and posterior to pulmonary trunk with situs inversus. The most obvious external abnormality is relation of great vessels with aorta being generally anterior. The commonest relation is aortic root right and anterior to pulmonary trunk (>80% of cases) with situs solitus and left and anterior to pulmonary trunk in situs inversus.202,203 Aortic valve is usually superior to pulmonary trunk as it is supported by a muscular infundibulum and the muscular infundibulum on the left side is mostly absorbed leading to mitral–pulmonary continuity. However, conal anatomy can vary as a there can be bilateral subarterial conus, subpulmonary conus with absent subaortic conus, and rarely bilaterally absent conus. Variations in great vessel relationship are reported more commonly with a VSD, anterior-posteriorly related great vessels, aortic root left and anterior, right and posterior or left and posterior to pulmonary trunk.

Associated Lesions202-205 Nearly half of the patients with d-transposition of great vessels have no other associated anomaly except a persistent foramen ovale or ASD and PDA (Fig. 72.136). VSD is the commonest associated anomaly (40–45%); combination of VSD and LVOT obstruction (pulmonary stenosis) are observed in 10%, and an isolated LVOT obstruction in approximately 5% of cases. Less commonly encountered anomalies are AV valve abnormalities, aortic obstructions, arch anomalies, and anomalies of systemic and pulmonary venous connections.

Echocardiographic Evaluation Two-Dimensional Echocardiography The usual segmental analysis is essential as for any other congenital cardiac anomaly. After defining the situs, subcostal coronal and apical four-chamber views provide the AV connection. Anterior tilt from subcostal coronal and apical four-chamber views profiles first the posteriorly placed great vessel that bifurcates into two, that is, PA arising from LV with mitral–pulmonary continuity (Fig. 72.135). Further angulation profiles the anteriorly placed great vessel with muscular infundibulum (subaortic conus),

Fig. 72.136: Two-dimensional echocardiography in subcostal view in a case of complete transposition of great vessel (TGA) with color flow mapping, showing a restricted patent foramen ovale (PFO; arrow). (LA: Left atrium; RA: Right atrium).

arising from RV. Subcostal sagittal view in different planes profiles the discordant ventriculoarterial connection, parallel course of great vessels, and conal anatomy. In patients with bilateral conus, fibrous discontinuity between both semilunar valves and AV valves is present, usually there is associated VSD and variation in great vessel relationship, and coronary pattern may coexist. This conal anatomy can be well profiled in subcostal sagittal, coronal, and PLAX views. PLAX view demonstrates parallel relation of great vessels and abrupt posterior turn of pulmonary trunk immediately after origin (Fig. 72.135). The parallel arrangement of great vessels is suggestive of d-transposition of great vessels, but is not diagnostic, as it can be found in other ventriculoarterial connections such as DORV with malposed great vessels. High PSAX and modified suprasternal long-axis views also profile the origin of aorta from the morphological RV. In a normal heart, great vessels have a wrap around relationship, that is, pulmonary trunk arises from RV and takes a leftward turn while aorta after arising from the LV turns to the right (circle sausage appearance; Figs 72.137A and B). With normally related great vessels, in PSAX view, aorta is right and posterior to pulmonary trunk. With complete transposition of great vessels, both outflows are in parallel as seen in PLAX (Figs 72.138A and B) and subcostal sagittal views. PSAX view profiles the spatial relationship of great vessels, as double circles, aorta right and anteriorly or directly anterior and less commonly aorta left and anterior and posteriorly placed pulmonary trunk. As both outflows are at different levels, usually both


A

1655

B

Figs 72.137A and B: Two-dimensional echocardiography in parasternal long-axis view (Figure A) and parasternal short-axis view (Figure B) at the level of the great vessels from an infant with transposition of great vessel (TGA) showing right and anterior position of the aorta as compared to the pulmonary artery. Arrow shows the origin of the left main coronary artery. (Aorta: Ascending aorta; PA: Pulmonary artery). (RV: Right ventricle; LV: Left ventricle).

A

B

Figs 72.138A and B: Two-dimensional echocardiogram in subcostal coronal view with anterior tilt. (A) Shows the origin of the aorta from the right ventricle; (B) Shows the origin of the pulmonary artery (and pulmonary artery branching) from the left ventricle. (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

semilunar valves cannot be profiled in the same plane. Main PA and its branches are seen at level of a cross section across aortic valve, and a cross section across pulmonary valve provides an image of RVOT. Apical four-chamber view may demonstrate the initial outflow tract dividing into branch pulmonary arteries followed by opening of the aorta in a further anterior tilt (Figs 72.139A and B).

Chamber Size206–210 After birth in simple (or complete) transposition of great vessels with intact ventricular septum, with the fall in PVR during first few weeks of life, left ventricular mass does not

increase and left ventricular posterior wall thickness starts regressing as the LV is supporting the pulmonary circulation (Figs 72.140A and B). The RV is systemic ventricle and LV is pulmonary ventricle in complete transposition of great vessels with intact ventricular septum. Four-chamber and subcostal coronal views show dilated RA and RV and the interventricular septum bulges toward the LV, giving the configuration of a banana to the LV (banana-shaped LV). The motion of the upper part of the ventricular septum is normal in 50% of patients, that is, moving posteriorly in systole while in the remainder, septal motion is abnormal, remaining flat or moving anteriorly during systole and this may also create a dynamic form of subpulmonary stenosis

1656


A

B

Figs 72.139A and B: Two-dimensional echocardiography in apical four-chamber view with anterior tilt showing the origin of pulmonary artery (PA) from the left ventricle (LV). Further anterior tilt shows the origin of aorta (Ao) from right ventricle the (RV). Ventricular arterial discordance.

A

B

Figs 72.140A and B: Two-dimensional echocardiography in parasternal long-axis view in a 1-year-old patient with transposition of great vessel (TGA) with intact ventricular septum. Shows the thinned out posterior wall of the left ventricle (2.7 mm). M-mode echocardiography of the same showing the regressed left ventricle (LV).

often associated with systolic anterior motion of the mitral valve. These findings may be seen in apical four-chamber view with anterior tilt and PLAX views. On M-mode, systolic anterior motion of the anterior leaflet of mitral valve is easily recognized. Features to be assessed by echocardiography while evaluating a child with complete transposition of great vessels with intact ventricular septum for primary arterial switch operation include:211,212 • LV geometry • LV mass index (Table 72.15) • LV posterior wall thickness index (<0.3 mm taken as regressed)

• •

LV volume index LV mass/volume ratio. With intact interventricular septum, RA and RV are always dilated as seen in apical four-chamber and subcostal coronal views. In subcostal sagittal and PSAX views, RV dominates with a circular configuration while the LV takes on a crescentic shape. In case of elevated left ventricular pressure as with a nonrestrictive VSD, large PDA, large aortopulmonary collaterals, significant left ventricular outflow obstruction, or pulmonary arterial hypertension, the circular shape of LV will be maintained with normal posterior wall thickness and LV mass.


1657

Table 72.15: Left Ventricular Mass and Volume Indexed to Body Surface Area in m2.204

Newborns Infants

Volume (mL) Enddiastole

Two-dimensional (2D) Mass (g) End-diastole

M-mode (g) End-diastole

Mass/Volume Index (g/mL)

31.3 ± 6.1

47.7 ± 12.7

59.8 ± 21

1.57 ± 0.4

38.7 ± 5

48.8 ± 8

56.6 ± 15

1.27 ± 0.2

Children (1–4 years)

54.6 ± 7.6

58.6 ± 10.3

61.9 ± 11.5

1.08 ± 0.2

Children (4–8 years)

59.8 ± 6.9

61.9 ± 7.1

69 ± 24

1.05 ± 0.1

Children (8–12 years) Children > 12 years

64 ± 6

66.9 ± 7.6

88.2 ± 20

1.04 ± 0.1

66.4 ± 7.8

74.1 ± 9.8

91.2 ± 40

1.1 ± 0.1

A

B

Figs 72.141A and B: Two-dimensional echocardiography showing balloon atrial septostomy with echocardiographic imaging in a case of transposition of great vessels (TGA). (A) Subcostal sagittal view showing the catheter in inferior vena cava (IVC). (B) Subcostal coronal view showing the inflated balloon in left atrium. (B: Balloon; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Associated Defects Septal Defects Interatrial Communication: Most commonly it is a patent foramen ovale. Fossa ovalis ASD occurs only in 5% of cases with complete transposition of the great vessels. Interatrial communication as a site of bidirectional shunting results in good intracardiac mixing if ASD is of adequate size. Subcostal sagittal and coronal views are used to profile the atrial communication and color flow mapping is used to assess the direction of shunt, which is usually bidirectional (left to right during systole, i.e. with an atrial “v”-wave, and right to left during diastole, i.e. with atrial “a”-wave). M-mode with color flow mapping across the ASD is the best method to profile the direction of shunting. It is very important to assess adequacy of interatrial communication with intact ventricular septum or small VSD for better

mixing, and with large VSD or PDA to decrease left atrial pressure and provide good mixing at the level of atria. In case of restrictive interatrial communication, echocardiography shows a dilated LA, interatrial septum bowing toward the RA, and turbulent flow across the interatrial communication with Doppler color flow mapping. PW Doppler interrogation reveals gradient across the interatrial communication. Echocardiographyguided balloon atrial septostomy to enlarge the interatrial communication can be done in the intensive care setting in neonates if the interatrial communication is restrictive and arterial switch operation is not planned immediately (Figs 72.141A and B). 2D echocardiogram from subcostal sagittal view is used to profile the course of balloon catheter from IVC to RA and then to LA. Subcostal coronal view is used to profile the catheter course during septostomy and to determine the size of ASD and flow across ASD after the procedure.

1658


Ventricular septal defect: Features of VSD to be assessed include: • Location of VSD. • Size of VSD. • Direction of shunt. • Relation of AV valves to VSD. • Relation of outflow tracts to VSD. The most significant and frequently occurring defect in complete transposition is a VSD, which can be small, large, single, or multiple (Fig. 72.142). The most characteristic defects are those that open beneath the ventricular outlets with the muscular outlet septum malaligned with the rest of the ventricular septum with overriding of one of the great vessels, most commonly the PA (posterior great vessel). These defects can have a posteroinferior muscular rim or may extend to perimembranous area. Frequently, these defects are crossed by the tension apparatus of tricuspid valve, which often inserts to a papillary muscle arising from the outlet septum. The outlet septum can be malaligned to LV causing pulmonary stenosis or anteriorly causing subaortic narrowing. In cases of anterior malalignment, arch anomalies such as CoA or arch interruption may be associated. The latter anomalies are more commonly seen in DORV with subpulmonary VSD, a close differential diagnosis of TGA. The VSD can extend to the inlet septum. These defects are hidden beneath the septal leaflet of tricuspid valve. When the defect extends into inlet septum, there is potential for straddling and overriding of tricuspid valve. With perimembranous VSD extending to inlet

Fig. 72.142: Two-dimensional echocardiography from a one and half-month-old child with transposition of great vessels (TGA). Parasternal long-axis view showing the presence of a large perimembranous ventricular septal defect () and posterior malalignment of the septum (arrow). (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle PA: Pulmonary artery).

septum, there is potential for septal leaflet of tricuspid valve to get prolapsed into the subpulmonary area and cause subpulmonary stenosis. Other types of defects that can be found are of AV canal type, multiple muscular, large apical muscular, and doubly committed VSDs. With a doubly committed defect, aorta is usually left-sided and there are increased chances of the presence of coronary anomalies. On echocardiographic evaluation, the following need to be assessed in patients with TGA: • VSD • Anomalies of AV valves – Attachment of tricuspid valve chordae to outlet septum or to the crest of ventricular septum – Overriding of AV valve – Straddling of AV valves – Any evidence of a cleft in an AV valve • Outflow tract abnormalities – Outflow tract obstruction. Outlet trabecular defect: Scanning from subcostal sagittal, subcostal coronal, and PLAX views would visualize a defect in outlet septum with or without extension to perimembranous area, intact subaortic infundibulum, and overriding PA. In addition, malalignment of outlet septum should be looked for. Outlet VSD with posterior malalignment (subpulmonary narrowing) can be profiled from subcostal coronal view with anterior tilt, subcostal sagittal view of left ventricular outflow, and PLAX view. Because of the posterior deviation of outlet septum, there is a direct route from LV to aorta making these children good candidates for intraventricular re-routing from LV to aorta. While evaluating for intraventricular re-routing of LV to aorta, size of VSD in relation to aortic valve annulus needs to be assessed in addition to relation of AV valves to VSD. If the VSD is smaller in relation to aortic valve annulus, then it needs enlargement during intraventricular repair. In the presence of straddling of AV valve, biventricular repair will not be possible and the patient would need to undergo a Fontan procedure. Anterior malalignment of outlet septum (subaortic narrowing) can also be profiled from subcostal sagittal view, subcostal coronal view of RV outflow, and PLAX view. The anterior malalignment of outlet septum causes subaortic narrowing and produces a long, oblique course from the LV to aorta. This makes intraventricular repair extremely difficult. With anterior malalignment of outlet septum, chances of arch anomalies are higher so a careful evaluation of aortic arch from suprasternal long-axis view is mandatory to rule out a hypoplastic transverse arch, coarctation, or arch interruption.


1659

With outlet VSD having perimembranous extension, septal leaflet of tricuspid valve can prolapse across the VSD into subpulmonary outflow leading to subpulmonary narrowing, as mentioned previously. This can be profiled from subcostal coronal and apical four-chamber views with anterior tilt. Inlet ventricular septal defect: Inlet VSD can be best profiled from four-chamber views (apical or subcostal coronal). Four-chamber (subcostal coronal and apical) views are also useful to profile overriding of AV valves and straddling of tricuspid valve if present. In addition, a modified subcostal sagittal view at the level of AV valves (en face view) can also define the presence of overriding or straddling. Mitral valve straddling can also be profiled from PLAX view as the mitral valve chordae cross the VSD and insert on the opposite side of septum. Doubly committed ventricular septal defect: Doubly committed VSD is best profiled from a combination of subcostal coronal and sagittal views, and PLAX and PSAX view. These views show the defect in outlet septum and presence of aortic and pulmonary valve continuity. Scanning from subcostal (coronal and sagittal), apical, and parasternal (long-axis and short-axis) views are used to define muscular VSDs. Color flow mapping helps in defining the direction of shunt. With nonrestrictive VSD, direction of shunting is left to right during diastole and right to left during systole. With restrictive VSD, a turbulent jet from right to LV will be found. Continuous wave Doppler interrogation shows a pressure gradient across the VSD as well as the direction of shunt. Patent ductus arteriosus (Fig. 72.143): Suspicion of presence of ductus arteriosus in complete transposition occurs when on color flow mapping, reverse flow is seen in PA from subcostal coronal with anterior tilt and subcostal sagittal views. In complete transposition of great vessels, because of the altered spatial relationship of great vessels, the total length and anatomy of ductus is easily profiled from suprasternal long-axis view. Color flow mapping and pulsed Doppler interrogation is used to define direction of shunting and magnitude of shunt across the ductus. With a large PDA, as PA pressures are systemic, direction of shunting is bidirectional, PA to aorta during systole and aorta to PA during diastole if the PVR is lower than systemic. With the development of pulmonary vascular obstructive disease, direction of shunt becomes PA to aorta during diastole too.

Fig. 72.143: Two-dimensional echocardiography. Suprasternal view in a 6-day-old child with complete transposition of great vessels showing a large patent ductus arteriosus (PDA; arrow). (Des. Ao: Descending aorta; PA: Pulmonary artery).

With restrictive PDA, color flow mapping reveals turbulent flow from aorta to PA. With continuous wave Doppler interrogation of ductus, a high velocity continuous signal peaking in late systole is obtained.

Left Ventricular Outflow Tract Obstruction213 Left ventricular outflow obstruction can occur with an intact ventricular septum as well as in the presence of a VSD. Such lesions can be found at the level of valve or can be subvalvular. Isolated valvular stenosis is rare and usually occurs in combination with subvalvular obstruction, which can be dynamic, fixed, or both. Dynamic left ventricular outflow obstruction (Fig. 72.144): With intact ventricular septum or small VSD, the RV has systemic pressure; interventricular septum may bulge toward LV in systole, causing dynamic subpulmonary obstruction. In addition, this dynamic subpulmonary obstruction causes systolic anterior motion of anterior leaflet of mitral valve, and midsystolic closure of pulmonary valve. 2D echocardiography in apical fourchamber, subcostal coronal, and PLAX views shows bulging of interventricular septum toward LV during systole. M-mode through the mitral valve clearly reveals systolic anterior motion of anterior leaflet of mitral valve and across the pulmonary valve shows midsystolic valve closure. Color flow mapping reveals mild turbulence across LVOT, and continuous wave Doppler usually reveals pressure gradients. In its severest form it behaves

1660


Fig. 72.144: Two-dimensional echocardiography. Parasternal long-axis view in a case of complete transposition of great vessels (TGA) with intact interventricular septum showing systolic anterior motion of the mitral valve (arrow). This creates a dynamic left ventricular outflow tract obstruction. (Ao: Aorta; IVS: Interventricular septum; LV: Left ventricle; PA: Pulmonary artery).

Fig. 72.145: Two-dimensional echocardiography with parasternal long-axis view showing posterior malalignment of the ventricular septum leading to subvalvular left ventricular outflow tract obstruction (arrow) in a case of transposition of great vessels (TGA) with ventricular septal defect (VSD) and pulmonary stenosis. (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

like hypertrophic cardiomyopathy. The obstructive lesion associated with septal bulging is more likely to occur with anteroposteriorly related great vessels than side-by-side– related great vessels. Milder form of septal bulging can be exaggerated by presence of fibrous ridge located on the septal bulge. Fixed anatomical obstruction: Fixed LVOT obstruction, if significant, results in LV becoming spherical and thick walled. Fixed obstruction occurs because of: • Subpulmonary fibrous ridge/fibrous subpulmonary membrane or ring. 2D echocardiography in fourchamber (subcostal coronal and apical) views with anterior tilt and PLAX view reveals presence of discrete ridge/membrane in subpulmonary area. This fibrous ridge can be elongated giving a tunnel type lesion. On color flow mapping, turbulence starts below the pulmonary valve, and on pulsed or continuous wave Doppler, severity of stenosis can be graded. • Valvar pulmonary stenosis is usually due to a bicuspid pulmonary valve. 2D echocardiography in PSAX view can demonstrate the bicuspid pulmonary valve. Color flow mapping reveals that turbulence starts at the level of pulmonary valve. • Anomalous attachment of the tension apparatus of mitral valve across the outflow tract or accessory mitral valve tissue can also cause LV outflow obstruction. This can be profiled best in a five-chamber view (Fig. 72.146).

Fig. 72.146: Two-dimensional echocardiography using subcostal coronal view with anterior tilt in a child with complete transposition of great vessels (TGA) showing prolapse of accessory mitral valve tissue into the left ventricular outflow tract (LVOT, arrow), causing obstruction. (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

• •

All these lesions can occur with intact ventricular septum as well as with VSD. Malalignment of outlet septum: With nonrestrictive outlet VSD, posterior malalignment of outlet septum may narrow the subpulmonary outflow tract. Subcostal coronal view with anterior tilt and PLAX view can profile the posterior malalignment of outlet septum (Figs 72.145 and 72.146).


•

Prolapse of septal leaflet of tricuspid valve or accessory tricuspid valve tissue across VSD: In this condition, the effective size of VSD becomes smaller due to prolapse of accessory tissue or septal leaflet of tricuspid valve. 2D echocardiography from subcostal coronal, subcostal sagittal, and PLAX views can profile the VSD and prolapse of tricuspid tissue across the defect causing left ventricular outflow obstruction. Color flow mapping is used to define level of obstruction and direction of shunt across the VSD.

Coronary Arteries The arterial switch operation for repair of complete transposition requires the mobilization and reimplantation of the coronary arteries. Whenever the position of the aortic root is abnormal, the origin of the coronary arteries deviates from those found in the normal heart. Thus, identification of coronary artery anatomy becomes an integral part of the preoperative echocardiographic examination of a child with complete transposition of great vessels. Coronary anomalies can be correctly diagnosed preoperatively with echocardiography in 95% of the patients. Sinuses are described from PSAX view and labeled as left-facing sinus (left side-sinus I) and rightfacing sinus (right side-sinus II). In most cases, the orifice of the coronary artery is situated approximately in the middle of the sinus of Valsalva just below the sinotubular junction; minor deviations from this central position are found frequently. In general, the origin and proximal course of the coronary arteries can be profiled from modified PSAX view at the level of great vessels and apical four-chamber and subcostal coronal views. From the PSAX view at the level of great vessels, relationship of great vessels and sinuses (I or left-facing, II or right-facing, and noncoronary) should be defined.

Coronary Artery Patterns in Transposition of the Great Arteries214–219 Left Anterior Descending and Circumflex Coronary Arteries from Sinus I, and Right Coronary Artery from Sinus II • •

Usual coronary pattern in complete transposition Demonstration of separate origin of coronaries from respective sinuses in PSAX view at the level of great vessels and subcostal coronal view with anterior tilt

•

•

1661

Imaging the bifurcation of LCA into LAD and circumflex vessels in PSAX view, PLAX view with anterior tilt, and subcostal coronal view with anterior tilt Absence of retropulmonary course of a coronary artery (between mitral valve and the pulmonary trunk) in apical four-chamber, subcostal coronal, and PSAX views.

Circumflex Coronary Artery from Right Coronary Artery (from Sinus II), Left Anterior Descending Coronary Artery from Sinus I • •

•

•

Second most common pattern in complete transposition Demonstration of separate origin of coronaries from respective sinuses in PSAX view at the level of great vessels and subcostal coronal view with anterior tilt Demonstration of origin of circumflex coronary artery from RCA and then retropulmonary course of circumflex vessel (between mitral valve and the pulmonary trunk) in apical four-chamber, subcostal coronal, and PSAX views Absence of bifurcation of LCA into LAD and circumflex in PSAX view and subcostal coronal view with anterior tilt.

Single Right Coronary Artery • •

• •

Demonstration of single coronary ostium arising from sinus II (right-facing sinus) in PSAX view Imaging origin of LCA from RCA and then its retropulmonary course between mitral valve and pulmonary trunk. This can be defined from modified PSAX (by moving the transducer superior and rightward), apical four-chamber, and subcostal coronal views Demonstration of bifurcation of left main coronary artery into LAD and circumflex branches Very rarely, LAD and circumflex coronary arteries have separate origins from the right sinus. In this scenario, LAD coronary artery courses anterior to aorta and the circumflex artery has a retropulmonary course to reach the left AV groove. PSAX view at the level of great vessels profiles origin of coronary artery from sinus II, retropulmonary course of circumflex, and course of LAD artery anterior to aorta. Four-chamber views (subcostal coronal and apical) in posterior plane profile retropulmonary course of circumflex and anterior tilt from this view profiles LAD artery coursing anterior to aorta.

1662


from left-facing sinus (sinus I). In this scenario, the circumflex artery after arising from right courses retropulmonary to reach the left AV groove, and RCA courses anterior to aorta after its origin from left.

Single Left Coronary Artery (Figs 72.147 and 72.148) Less common than single RCA: Demonstration of single coronary ostium arising from sinus I (left-facing sinus) in PSAX view and origin of RCA from left. Its course anterior to aorta can be profiled in PSAX, apical four-chamber, and subcostal coronal view with anterior tilt. The coronaries can arise from a single stump, all three coronaries separately or two coronaries with separate origin. Rarely, circumflex artery arises from RCA and takes a retropulmonary course to reach left AV groove. Subcostal coronal view, apical four-chamber view, and PSAX view at the level of great vessels shows retropulmonary course of circumflex artery, while these views in anterior plane show the RCA anterior to aorta.

Inverted Origin of Coronaries • •

•

•

A

Demonstration of separate origin of coronaries in PSAX view. Imaging the retropulmonary course of LCA arising from right-facing sinus (sinus II) and its bifurcation into LAD and circumflex branches. This can be profiled in PSAX, apical four-chamber, and subcostal coronal views. Demonstrating origin of RCA from left-facing sinus (sinus I), its course anterior to aorta in PSAX, and fourchamber views with anterior tilt. Less commonly there can be inverted origin of circumflex only and origin of RCA and LAD artery

Intramural Coronary Artery An intramural coronary is a potentially significant risk factor for transfer of the coronaries as part of the arterial switch operation for transposition of great arteries. Preoperative diagnosis is advantageous because it helps to prevent accidental injury to the intramural coronary artery during transection of the aortic root and excision of the coronary artery ostium from the aorta. • Origin of coronary artery from contralateral sinus, as in case of left main or LAD artery origin from rightfacing sinus or RCA from left-facing sinus profiled in PSAX view. Their orifices are placed adjacent to the commissure (usually intercoronary). • Identification of major coronary artery coursing between the two arterial roots in PSAX, apical four-chamber, and subcostal coronal views with posterior to anterior tilt. After origin, the proximal portion of coronary artery runs parallel to the aortic wall and perpendicular to the intercoronary commissure, giving a “double border appearance” to the posterior aortic wall. In approximately 10% of cases, the orifice of a coronary artery will arise close to one of the valve commissures that can be defined in PSAX view at the level of great vessels. With coronary ostia near the commissure, chances of

B

Figs 72.147A and B: Two-dimensional echocardiography in parasternal short-axis views in two cases of complete transposition of great vessels (TGA) showing the origin of the coronary arteries. (A) In case A, the coronaries arise from a single stump. In case B, all the three coronary arteries arise separately. (Ao: Aorta; LAD: Left anterior descending artery; RCA: Right coronary artery; LCx: Left circumflex artery).


1663

Fig. 72.148: Two-dimensional echocardiography with parasternal short-axis view in an infant with TGA showing both the coronary artery systems arising from a common sinus (sinus I with two separate origin). (Ao: Aorta; LMCA: Left main coronary artery; RCA: Right coronary artery).

A

B

C

Figs 72.149A to C: (A) Two-dimensional echocardiography in parasternal short-axis view in an infant with TGA showing the origin of dual right coronary artery (RCA). (A) RCA from sinus II; (B) Left main and RCA from sinus I; (C) Apical four-chamber view with tilt showing the presence of the left circumflex artery in the left atrioventricular (AV) groove. (Ao: Aorta; LA: Left atrium; LAD: Left anterior descending artery; LCT: Left common trunk; LCx: Left circumflex artery; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; RCA: Right coronary artery; RV: Right ventricle).

neopulmonary regurgitation are higher after arterial switch operation. Less commonly, ostia can also arise above the commissures in the tubular portion of the aorta

(higher origin of coronary). Occasionally, two ostia will arise from the same sinus (usually sinus II; Fig. 72.148). Rarely there may be a dual RCA219 (Figs 72.149A to C).

1664


PART 8: ATRIOVENTRICULAR AND VENTRICOARTERIAL DISCORDANCE

ATRIOVENTRICULAR AND VENTRICOARTERIAL DISCORDANCE Congenitally corrected transposition of great vessels (CTGA) or L-transposition of great vessels is characterized by discordant AV connections combined with discordant ventriculoarterial connection. Thus, with situs solitus, morphological RA on right side is connected to morphological LV on right side (L-looped ventricles), which is in turn connected to PA.220 On the other hand, morphological LA is connected to morphological RV on left side, which gives rise to aorta (Figs 72.150 and 72.151). This anomaly can be encountered with situs solitus or with situs inversus. Anomalies having univentricular AV connection such as atresia of one of the AV valves, and double inlet LV with hypoplastic RV on left side should be excluded. The aorta usually arises left and anterior to pulmonary valve (L-transposed aorta), but rarely aorta can be right and anterior to pulmonary trunk. There will be fibrous continuity between mitral leaflet and the pulmonary valve. On the other side, aorta is separated from tricuspid valve by the muscular infundibulum.

Fig. 72.150: Two-dimensional echocardiography. Subcostal coronal view in a patient of corrected transposition of great vessels (CTGA) showing atrioventricular discordance. (LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; RV: Right ventricle).

Associated Defects221–232 The commonest associated anomaly is left AV valve (tricuspid valve) abnormalities.220 The other lesions are VSD and pulmonary stenosis. However, any kind of congenital cardiac malformation can be encountered.

Coronary Artery Anatomy233–237 Usually coronary arteries arise from two aortic sinuses, which are adjacent to the pulmonary trunk. The anatomy is mirror image relative to the arrangement seen in the normal heart. Right side coronary artery exhibits the pattern of morphological LCA and left-sided coronary artery exhibits the pattern of morphological RCA. The most frequent coronary anomaly is single coronary artery. Segmental analysis is crucial for the diagnosis of corrected transposition and 5% of corrected transposition cases occur in the setting of situs inversus. The discordance between the atrial (abdominal) situs and the cardiac position is itself a pointer to possibility of CTGA, for example, dextrocardia with situs solitus and levocardia with situs inversus, and 25% of patients with corrected transposition have cardiac malposition, either

Fig. 72.151: Two-dimensional echocardiography. Subcostal coronal view with anterior tilt in a child of corrected transposition of great vessels (CTGA) and ventricular septal defect (VSD; star) showing the L-looped ventricles with aorta arising from morphological left-sided right ventricle and pulmonary artery arising from morphological left ventricle (right-sided). Mitral and pulmonary valves show continuity (arrow). (Ao: Aorta; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).


1665

dextrocardia or mesocardia. As with d-transposition, echocardiographic diagnosis of corrected transposition of great vessels is based on sequential chamber analysis and demonstrating abnormal AV and ventriculoarterial connections. After defining situs from subcostal shortaxis view, both atria should be defined from subcostal coronal, and sagittal and apical four-chamber views, to profile discordant AV connection, that is, morphological RA connects to morphological LV. The presence of atrial situs (which generally goes along with the abdominal situs) opposite to the cardiac position, that is, dextrocardia with situs solitus and levocardia with situs inversus, is in itself generally a setting of corrected transposition of great arteries. In situs solitus and levocardia: From the subxiphoid view, as the transducer is angled superiorly from the coronal view, the LV, which lies inferiorly and to the right is viewed. Further superior tilt brings the RV in view, which lies to the left of the morphological LV. In situs inversus and dextrocardia: The morphological RA is left-sided. On angulating the transducer superiorly in the subxiphoid coronal view, the LV first comes under view. It lies inferiorly and to the left. On further superior tilt, the RV is viewed, lying to the right of the LV. Four-chamber views show malalignment between interatrial septum and inlet part of interventricular septum. This is seen as a rightward curve of atrial septum in situs solitus. After defining AV connections, ventri-

culoarterial connections should be defined from subcostal coronal and apical four-chamber views (Fig. 72.151). To demonstrate ventriculoarterial connections, it is important to trace ventricular outflow tracts to the great arteries. In the subcostal view, after the ventricles are identified, continuing superior angulation first shows the PA arising from the LV. This artery is deeply wedged between the mitral and tricuspid valves and the pulmonary valve is seen to be continuous with the mitral valve. This view also profiles the LVOT and its abnormalities. Continuing the superior angulation shows the aorta arising from the RV (Figs 72.151 and 72.152). It is seen to lie furthest to the left and follows a straight course upward. It has no continuity with the tricuspid valve. The two great vessels are seen to have a parallel course. In those with suboptimal subcostal windows the aorta may not always be visualized in this view because the ribs prevent further anterior tilt. The next view is the apical four-chamber view. This may be suboptimal in cases with mesocardia or dextrocardia. In these cases, the transducer may have to be placed very close to the sternum or some times over it. This view, however, shows the features of discordant AV connection very well. In situs solitus and levocardia, the left-sided AV valve (tricuspid valve) is seen to attach more apically compared to the right-sided AV valve (mitral valve; Figs 72.153 and 72.154). This view also shows the moderator band of the leftsided morphological RV very clearly. The apex of the RV (left-sided) frequently appears foreshortened in this view.

Fig. 72.152: A case of corrected transposition of great vessels (CTGA). Subcostal paracoronal view with slight tilt to the right showing the pulmonary artery arising from the right-sided left ventricle and its division. (LA: Left atrium; LPA: Left pulmonary artery; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle; RPA: Right pulmonary artery).

Fig. 72.153: Two-dimensional echocardiography. Apical fourchamber view from a 4-year-old child with corrected transposition of great arteries showing atrioventricular discordance, reverse offsetting of atrioventricular (AV) valves (arrow), and moderator band in morphological right ventricle on left side (arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1666


The membranous septum is clearly seen in this view situated between the morphological LV (right-sided) and LA (left-sided). Anterior tilt from the apical four-chamber view first shows the PA and LVOT (Fig. 72.155). On further anterior tilt, the aorta should be seen to the left of the PA. This view may not always be optimal, because on continuing anterior tilt, transducer contact with the chest wall is frequently lost. Loss of offsetting remains a characteristic feature. (Figs. 72.156A and B).

Subcostal sagittal view also defines ventriculoarterial connections, origin of aorta from RV, and PA from LV and parallelly arranged great vessels. Parasternal long axis is oriented in a much more vertical direction than usual. As ventricular septum in corrected, transposition is sagittally oriented, the long-axis view may be confusing, particularly in the presence of large perimembranous VSD with inlet extension giving the impression of single ventricle. This occurs because the ventricles are side-byside with sagittally arranged interventricular septum, and

Fig. 72.154: Two-dimensional echocardiography with zoomed up view of the crux of the heart showing atrioventricular discordance and reverse offsetting of the atrioventricular (AV) valves (arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 72.155: Two-dimensional echocardiography with fourchamber view with anterior tilt in a case of corrected transposition of great vessels (CTGA) showing a regressed left ventricle; there is no left ventricular (LV) outflow tract obstruction. (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

A

B

Figs 72.156A and B: Two-dimensional echocardiography. Apical four-chamber view in a case of corrected transposition of great vessels (CTGA) showing the comparison of the normal heart with normal offsetting (arrow) (Figure A) of atrioventricular valves as compared to the CTGA with reverse offsetting and the trabeculated right ventricle (RV) with a moderator band (Figure B). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).


the plane of ultrasound passes through an AV valve and semilunar valve without passing through any portion of the interventricular septum. PLAX view profiles parallel-arranged great vessels and multiple chords attaching to interventricular septum with tricuspid valve and aortic discontinuity. Because the ventricles and great vessels are side-by-side, in long-axis view of LV and PA the adjacent RV and aorta may also be visualized. Minor posterior tilting from PLAX view shows the posterior AV valve continuity with the posterior arterial valve. The PSAX view at the level of great vessels defines spatial relationship of great vessels. As great vessels have parallel arrangement, these are seen as a double circle in PSAX view, usually aorta to left and anterior to PA. However, in corrected transposition, any spatial orientation of great vessels is possible, as in d-transposition of great vessels. As both semilunar valves are not at the same level, cross section through the aortic valve profiles main PA and its bifurcation and cross section through pulmonary valve profiles RVOT in long axis. PSAX view is oriented more horizontally in corrected transposition and ventricular septum is aligned in anteroposterior direction. Coronary artery can be defined from PSAX view; origin of RCA (anatomical left) can be profiled from left coronary cusp, although it is more difficult to profile the left coronary cusp than in d-transposition of great vessels. As aorta is left and anterior, ascending aorta ascends on left border of the heart straight up on the left and then arches, and descending aorta descends on the left behind the ascending aorta. High left parasternal view with anticlockwise rotation (ductal view) profiles the ductus and also the whole length of arch because of its leftward and anterior position. Usually, the aortic arch is leftsided with normal arch branching; demonstration of arch branches is important as right aortic arch occurs in 18% of cases with corrected transposition.

Associated Malformations Ventricular Septal Defect It is reported in 60–70% of patients with CTGA. The commonest is perimembranous defect (Fig. 72.151), which is subpulmonary and extends posteriorly toward the crux of the heart and erodes significantly the inlet septum. Fibrous continuity between mitral, tricuspid, and pulmonary valve is present. It is important to define VSD relation to AV valves and document if there is any overriding or straddling of AV valves, more commonly of tricuspid valve. In cases with

1667

Fig. 72.157: Two-dimensional echocardiography. Modified parasternal long-axis view showing the origin of the pulmonary artery from the left ventricle (LV) with prolapse of the mitral valve into the left ventricular outflow tract (LVOT; arrow) causing obstruction. (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

VSD extending to inlet septum, offsetting of AV valves is lost. Septal leaflet of tricuspid valve may prolapse through VSD, causing it to become hemodynamically smaller, or it may prolapse into subpulmonary area through the defect causing subpulmonary stenosis (Fig. 72.157). Muscular VSD can be profiled from a combination of views (fourchamber, parasternal long- and short-axis). These views define muscular boundaries of the defect and its extension (Figs 72.158 and 72.159). Doubly committed VSD is best profiled from subcostal coronal view and is roofed by the continuity between aortic and pulmonary valve leaflets. Color flow mapping shows direction of shunt, turbulent (restrictive) or laminar flow across the VSD (Fig. 72.159). Pressure gradient (difference in left and RV pressure) can be determined by use of continuous wave Doppler.

Tricuspid Value Abnormalities232 (Fig. 72.160) These are almost an essential part of CTGA and are seen in 90% of cases in autopsy series, although they are hemodynamically significant in 30% of cases only. The most common anomaly is valvular dysplasia, with or without apical displacement of the septal and or mural leaflet. Apical four-chamber, parasternal longaxis, and modified short-axis views are the best to define tricuspid valve anomalies, including thickening of valve leaflets and downward displacement of septal and mural leaflets. Atrialization, with thinning and dilatation of RV as seen in Ebstein’s anomaly with concordant AV and ventriculoarterial connections is rare with corrected

1668


A

B

Figs 72.158A and B: Two-dimensional echocardiography. Apical four-chamber view with color compare with anterior tilt showing the origin of the pulmonary artery from the left ventricle and the presence of supravalvular pulmonary stenosis (white arrow). A ventricular septal defect is noted (yellow arrow) in the anterior muscular plane. (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle).

Fig. 72.159: Two-dimensional echocardiography with color comparison showing a small anterior muscular ventricular septal defect (arrow) in a case of corrected transposition of great vessels (CTGA). (LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle; RA: Right atrium).

Fig. 72.160: Two-dimensional echocardiography. Apical fourchamber view with color flow mapping showing severe tricuspid regurgitation (TR) in Ebstein’s anomaly of the left-sided atrioventricular (AV) valve in a case of corrected transposition of great vessels (CTGA). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

transposition. With significant Ebstein’s malformation, hypoplasia of RV and occasionally subaortic obstruction can occur and should be properly defined. Other abnormalities can be short and thickened chordae that insert directly into ventricular wall, deformed and abnormal papillary muscles, dilatation of tricuspid valve annulus, and straddling of the left AV valve (Fig. 72.161). By color flow mapping, valvular regurgitation (more commonly) or stenosis of tricuspid valve should be defined. Less commonly, tricuspid valve stenosis can occur in congenitally corrected transposition due

to supratricuspid ring or membrane. From apical fourchamber and PLAX view, this membrane is seen as thin, linear echoes just above the tricuspid valve, attaching laterally to free wall of LA and medially to left atrial surface just above the crux. Color flow mapping shows turbulence beginning above the level of valve, and on pulsed or continuous wave Doppler interrogation, severity of obstruction can be defined. Rarely cor triatriatum sinister may be the cause of tricuspid inflow obstruction. Best views to profile cor triatriatum are PLAX and fourchamber views. In PLAX view, the membrane extends


1669

from posterior wall of LA toward interatrial septum. In apical four-chamber view, the membrane extends from lateral wall of LA above the left atrial appendage toward the interatrial septum. Cor triatriatum can be obstructive or nonobstructive. Color flow mapping and pulsed Doppler imaging should be used to define any obstruction to tricuspid inflow. Mitral valve abnormality with CTGA: Dysplastic mitral valve can occur, but is not common.

is obtained with the use of pulsed and continuous wave Doppler interrogation. Often a PA band is placed in the restricted VSD or intact septum subgroup as a measure to prepare the LV for the subsequent double switch surgery (Fig. 72.164). Care should be taken to separate the jet of VSD from pulmonary stenosis.

Left Ventricular Outflow Tract Obstruction Pulmonary stenosis occurs in approximately 30 to 50% of patients, with 85% of these in association with a VSD. The anatomical nature of pulmonary stenosis varies. Valvular stenosis is usually accompanied by one or the other variety of subpulmonary obstruction. Subpulmonary obstruction may take the form of fibrous diaphragm or an aneurysm of fibrous tissue that protrudes into LVOT (see Fig. 72.157). The fibrous tissue tags may originate from perimembranous septum, tricuspid or mitral valve, or even a leaflet of pulmonary valve (see Fig. 72.157). Posterior malalignment of outlet septum associated with VSD can also cause LVOT obstruction. The anatomical features of LVOT are best defined from subcostal coronal and apical four-chamber views with anterior tilt, and PLAX view (Figs 72.162 to 72.164). Peak pressure gradient

Abnormalities of RVOT are somewhat uncommon, occurring in about 10% of patients. Obstruction or severe regurgitation of tricuspid valve is commonly associated with outflow tract obstruction. In the setting of severe left AV valve regurgitation, one must be certain that the obstruction is not simply functional. As aorta is supported by the muscular infundibulum, muscular outflow obstruction may be dynamic. Other causes of obstruction can be anterior malalignment of outlet septum with VSD, subaortic membrane, valvular stenosis, and accessory mitral or tricuspid valve tissue. The RVOT can be best imaged from parasternal long-axis, subcostal coronal with anterior tilt, and subcostal sagittal views. Doppler interrogation can be difficult due to improper alignment, and a high parasternal or subcostal coronal with anterior tilt views are used in an attempt to align the Doppler beam. Coarctation of aorta is often associated with severe tricuspid regurgitation, VSD, hypoplasia of RV, and subaortic obstruction.

Fig. 72.161: Two-dimensional echocardiography in apical fourchamber view in a case of corrected transposition of great vessels (CTGA) showing Grade I straddling of the left atrioventricular valve (tricuspid) across the large inlet ventricular septal defect (arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Fig. 72.162: Two-dimensional echocardiography in subcostal view with anterior tilt and color flow mapping in corrected transposition of great vessels showing turbulence across left ventricular outflow tract (LVOT) (arrow) because of hypoplastic pulmonary annulus and main pulmonary artery (MPA). (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle; RA: Right atrium).

Abnormalities of Right Ventricular Outflow

1670


Fig. 72.163: Two-dimensional echocardiography in subcostal view with anterior tilt and color flow mapping in corrected transposition of great vessels (CTGA) showing turbulence across left ventricular outflow tract (LVOT) because of supravalvular pulmonary stenosis. (LV: Left ventricle; PA: Pulmonary artery; RV: Right ventricle) (arrow).

Fig. 72.164: Two-dimensional echocardiography in apical fourchamber view with anterior tilt showing a pulmonary artery (PA) band in situ with flow acceleration across it (arrow). (LV: Left ventricle; RV: Right ventricle; PA: Pulmonary artery).

PART 9: PULMONARY VEINS Evaluation of the pulmonary veins forms an essential component of any segmental analysis of the congenital heart. The indicators for the abnormal connection include dilated chambers to which the veins drain, right-to-left atrial shunting, nonvisualization of the veins to the LA (bald LA), and a small LA. In such a scenario it is equally essential to screen the systemic veins (SVC, IVC, innominate veins) for abnormal dilatation or increased flow. Echocardiographic views for demonstration of pulmonary venous connection to LA and their flow patterns are:238–241 • The subcostal view (Figs 72.165A and B): The coronal section clearly demonstrates right upper and left upper pulmonary venous connection to LA, while the sagittal section identifies the right upper and right lower pulmonary veins. • Apical four-chamber view (Figs 72.166 and 72.167): This view gives a clear visualization of the left-sided pulmonary veins and right upper pulmonary vein. Posterior tilt in apical four-chamber view at level of IVC shows the right lower pulmonary vein connection to LA. • Parasternal short- and long-axis views: PSAX and PLAX views show both left and right upper pulmonary veins. The descending aorta in short axis separates right and left pulmonary veins.

•

Suprasternal short-axis view (Crab view): This is the best view in the pediatric age group to demonstrate all four pulmonary veins that are located below the right PA (Figs 72.168A and B).

NORMAL FLOW PATTERN OF PULMONARY VEINS All pulmonary veins should be interrogated by color flow mapping followed by pulsed and continuous wave Doppler with attention to intercept angle, wall filter, and velocity scale. Pulsed Doppler sample volume should be placed distal to the orifice of the pulmonary vein as it enters the LA, so that Doppler velocity reflects the events occurring in pulmonary vein and not the LA. In normal subjects, the pulmonary vein Doppler recording consists of biphasic forward flow, “S”-wave in systole due to atrial relaxation and descent of floor of LA, “D”-wave in diastole due to fall in LA pressures with opening of mitral valve and rapid ventricular filling, and a small reversed “A”-wave occurring during LA contraction. The normal values for the S-, D-, and A-wave in subjects under the age of 50 years are nearly constant, except in newborns who have nearly equal S- and D-waves. Continuous high velocity pattern present in pulmonary veins in the first few days of life may be due to relatively


A

1671

B

Figs 72.165A and B: Two-dimensional echocardiography in subcostal coronal view with color flow mapping showing right upper and left upper pulmonary veins draining into left atrium (LA; arrows). LA: Left atrium; RA: Right atrium).

A

B

Figs 72.166A and B: Two-dimensional echocardiography in sagittal subcostal view showing right upper and right lower pulmonary veins draining to left atrium (LA; arrows). (LA: Left atrium; RA: Right atrium).

A

B

Figs 72.167A and B: Two-dimensional echocardiography in apical four-chamber view showing the right upper and left lower pulmonary veins connecting to left atrium (LA; arrows). (LLPV: Left lower pulmonary vein; RUPV: Right upper pulmonary vein).

1672

A


B

A

B

Figs 72.168A and B: Two-dimensional echocardiography in suprasternal short-axis view (crab view) with color compare showing all four pulmonary veins connecting to the left atrium (arrows). (LLPV: Left lower pulmonary vein; LUPV: Left upper pulmonary vein; RLPV: Right lower pulmonary vein; RUPV: Right upper pulmonary vein).

Figs 72.169A and B: Two-dimensional echocardiography in suprasternal short-axis view with color compare showing leftsided pulmonary veins (arrows) draining to the innominate vein. (Innom: Innominate vein).

hypoplastic and underperfused pulmonary veins during fetal life, which are suddenly exposed to increased pulmonary blood flow after birth with fall in PVR.

on the other hand has been reported. Usually, left-sided pulmonary veins connect anomalously to the derivatives of left cardinal system, that is, coronary sinus and the left innominate vein. Right-sided pulmonary veins usually connect to derivatives of right cardinal system, that is, SVC or IVC. However, as the developing splanchnic plexus is a midline structure, the possibility of cross connection exists. Most cases of PAPVC associated with an ASD with only 20% of cases having intact interatrial septum. Other associated heart defects can be VSD, LSVC, and complex congenital heart defects associated with isomerism. After sinus venosus ASD, the commonest type of PAPVC is left upper lobe pulmonary vein to left innominate vein followed by right pulmonary veins to IVC (Scimitar syndrome). The latter group is associated with hypoplasia of right PA and right lung, anomalies of bronchial system, horseshoe lung, pulmonary sequestration, and dextroposition of heart along with, on the chest X-ray, a Turkish swordlike shadow on the right heart border produced by the descending pulmonary venous channel formed by rightsided pulmonary veins connecting to IVC. While doing echocardiography, a high index of suspicion is required to diagnose PAPVC. In any patient with right atrial and RV dilation, all pulmonary veins should be defined on 2D echocardiography and color flow mapping connecting to LA, and all possible drainage sites should be interrogated with color flow, because in the case of supernumerary pulmonary veins, one can profile

ANOMALIES OF PULMONARY VEINS Abnormal Number of Pulmonary Veins Normally there are two right and two left pulmonary veins. The most common variation is the presence of a single pulmonary vein on either left or right side. There may be increased number of pulmonary veins. The number of pulmonary veins on one side could vary from three to five. The variation in number of pulmonary veins is of no clinical significance if they are connected normally to LA.

Anomalous Pulmonary Venous Return Partial anomalous pulmonary venous connection (PAPVC) is used to describe the condition where one or more but not all pulmonary veins connect abnormally (Figs 72.169A and B) and total anomalous pulmonary venous connection (TAPVC) is a term used when all four pulmonary veins connect abnormally to systemic veins or RA. When pulmonary veins are connected normally to posterior wall of LA but drain anomalously because of the orientation of the atrial septum, the condition is termed as partial or total anomalous pulmonary venous drainage (PAPVD/TAPVD). Almost every possible connection between pulmonary vein on one hand and various systemic venous tributaries


four pulmonary veins connecting to LA but an accessory pulmonary vein or a tributary of pulmonary vein may be draining anomalously. In majority of cases with PAPVC, there will be evidence of right-sided volume overload in the form of dilated RA and RV with paradoxical septal motion except in the case of PAPVC of a single pulmonary vein or PAPVC associated with stenosis (small shunt).

TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION242–246 All pulmonary veins form a confluence and that confluence drains to systemic venous system. The commonest site of drainage is left innominate vein followed by portal system, coronary sinus, SVC, RA, and rarely mixed type, that is, more than one site of abnormal connection. The goals of echocardiography are: • To define individual pulmonary veins • To ascertain that all pulmonary veins are draining to pulmonary venous confluence (PVC) or draining directly • Relation of PVC to LA, PA, and airways • Site of drainage of PVC/individual veins • Any evidence of obstruction at the site or during the course of the pulmonary venous channel • Adequacy of interatrial communication • PA pressures • Any associated heart defect.

Fig. 72.170: Two-dimensional echocardiography. Apical fourchamber view in a case of total anomalous pulmonary venous connection (TAPVC) showing markedly dilated right atrium and right ventricle. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1673

Steps in Diagnosis of Total Anomalous Pulmonary Venous Connection Features Common to all Forms of Total Anomalous Pulmonary Venous Connection Dilated right-sided structures (RA, RV, and PA; Fig. 72.170). • LA and LV (may appear smaller) • Interatrial septum bows toward left, with right-to-left shunt at atrial level (Fig. 72.171) • RV appears to compress the LV and on M-mode, evidence of paradoxical ventricular septal motion suggestive of RV volume overload is seen • Echocardiographic evidence of pulmonary hypertension may exist, in the setting of obstruction or flowrelated PA hypertension • Inability to image the pulmonary vein entrance to LA is the first echocardiographic suspicion that one may be dealing with TAPVC.

Pulmonary Venous Confluence (PVC) The common chamber to which all pulmonary veins connect before finally draining to systemic venous channel is referred to as PVC. PVC is profiled as an echo-free space, which lies in a plane posterior to LA but is separated from it. It is well seen in suprasternal short-axis and subaortic coronal views. In the subcostal sagittal view in its cross section below the right PA and posterior to the SVC, giving the appearance of a double circle. The size and orientation (horizontal and vertical) of PVC and its relation to LA is important when planning for surgery.

Fig. 72.171: Two-dimensional echocardiography with color compare in subcostal coronal view in a 6-month child with total anomalous pulmonary venous connection (TAPVC) showing rightto-left shunt at the atrial level (arrow). (LA: Left atrium; RA: Right atrium).

1674


After identifying the PVC, the next step is to profile individual pulmonary veins for their course and diameter because obstruction can occur at any level. This is the strong independent predictor of survival in TAPVC.

In case of supracardiac TAPVC (to vertical vein/SVC/ azygos vein), PVC lies horizontally oriented posterior and superior to LA (Figs 72.172A and B). This can be best visualized in suprasternal short-axis and subcostal sagittal views. In supracardiac TAPVC to left innominate vein, the ascending channel connecting to left innominate vein can be shown in suprasternal short-axis view (Fig. 72.173). In this view, the anomalous pulmonary venous connection gives the appearance of a large vascular collar surrounding the transverse arch. Color flow mapping in a vertical vein shows continuous low velocity flow directed away from the heart. There will be evidence of dilated innominate vein and SVC along with dilated rightsided chambers. In TAPVC to SVC or azygos vein, the innominate vein will be of normal caliber and in TAPVC to azygos or to SVC, the SVC will be grossly dilated. In a rare variety of TAPVC, that is, to azygos vein, the channel ascends posterior to right PA and joins the azygos vein (Fig. 72.174). The best view to define this anatomy is subcostal sagittal, high PSAX, and suprasternal short axis views. In case of intracardiac TAPVC (to RA/coronary

sinus), the PVC lies directly posterior to LA and all four pulmonary veins join ipsilaterally to that confluence at the same level (Fig. 72.175). In intracardiac type of TAPVC, with connection to RA, the PVC can be imaged draining directly to RA. Rarely the pulmonary veins can drain individually to RA. The views most commonly used are subcostal coronal, and sagittal and PSAX views. In TAPVC to coronary sinus, the dilated coronary sinus receiving all pulmonary veins bulges anterosuperiorly into LA and can be imaged easily in subcostal coronal, apical fourchamber, and PLAX views. In infracardiac TAPVC (to IVC/hepatoportal system), the pulmonary veins connect to vertical vein at a different level and the repair is more challenging (Fig. 72.176). The PVC is often small, inferior and posterior to LA, the descending venous channel (Des. PVC) passes through the diaphragm usually anterior to aorta, and joins a systemic vein or the hepatoportal system (portal vein, ductus venosus, left hepatic vein, and IVC). Three channels, two descending (aorta and the Des. PVC) and one ascending (IVC, which is dilated) can be defined in subcostal views. The short-axis view shows these three vessels in short axis. Subcostal sagittal view is the best view to define the origin of the PVC, its course, and connection to hepatoportal system. Pulse Doppler examination shows continuous low velocity flow signals or high velocity disturbed flow if there is obstruction, which is usually present in these cases. The flow in the descending pulmonary venous channel is away from the heart and continuous low velocity flow signals in IVC are directed toward the heart.

A

B

Orientation and Site of Drainage of Pulmonary Venous Confluence

Figs 72.172A and B: Suprasternal short-axis view with color flow mapping in a case of supracardiac total anomalous pulmonary venous connection (TAPVC). (A) Shows right- and left-sided pulmonary veins forming a pulmonary venous confluence; (B) Shows pulmonary venous confluence continuing as vertical vein. (PVC: Pulmonary venous confluence; RPA: Right pulmonary artery; VV: Vertical vein).


1675

Fig. 72.173: Two-dimensional echocardiography with color flow mapping. Suprasternal short-axis view in a patient with supracardiac total anomalous pulmonary venous connection (TAPVC) with color flow mapping showing the ascending vertical vein (VV) from the pulmonary venous confluence draining into the innominate vein, which together with the superior vena cava (SVC) is dilated. (Innom: Innominate vein; SVC: Superior vena cava; VV: Vertical vein).

Fig. 72.174: Two-dimensional echocardiography with colour flow mapping in suprasternal view in a case of supracardiac total anomalous pulmonary venous connection (TAPVC) showing the pulmonary veins from left and right sides ascending and draining to the azygos vein (arrows). (AZ: Azygos vein).

Fig. 72.175: Two-dimensional echocardiography with color flow mapping. Subcostal coronal view showing the pulmonary venous confluence draining to the coronary sinus (CS), right-to-left shunt across the patent foramen ovale (PFO; arrow), dilated right atrium (RA), and normal-sized superior vena cava (SVC). (CS: Coronary sinus; RA: Right atrium; PFO: Patent foramen ovale; SVC: Superior vena cava).

Fig. 72.176: Two-dimensional echocardiography with color compare. Subcostal sagittal bicaval view (modified) in a case of infradiaphragmatic total anomalous pulmonary venous connection (TAPVC) showing the pulmonary venous confluence continuing as the descending vertical vein (desc. VV) and then draining into the inferior vena cava through hepatic sinusoids (RA: Right atrium).

Rarely, a mixed form of TAPVC occurs in which pulmonary veins drain to two or more separate systemic venous sites. In this subgroup, multiple windows using 2D and color flow mapping must be used to image the connection of all four individual pulmonary veins. The most common type of mixed drainage connection is to coronary sinus and via vertical vein to left innominate vein.

Defining the Obstruction247 Color flow mapping and PW Doppler should be used to diagnose the presence of obstruction. Normal pattern in a pulmonary vein is laminar flow on color Doppler mapping and biphasic low velocity flow on pulse Doppler. If there is obstruction at any level, there will be turbulent, aliased flow on color flow mapping and

1676


high velocity disturbed flow on pulsed Doppler, which will not touch the baseline, and with more severe obstruction it will be continuous. The level of obstruction can be the following: • Long channel itself offers some resistance • Restrictive interatrial communication (Fig. 72.177) • In supracardiac TAPVC to left innominate vein, as the ascending channel passes between left PA and left bronchus (vascular ring), it gets compressed (so-called hemodynamic vise; Figs 72.178A and B)

•

At junction of venous confluence to the site of drainage (Fig. 72.179) • In infradiaphragmatic TAPVC • As channel passes through the diaphragm • Resistance offered by hepatoportal system. The tricuspid regurgitation velocity helps to predict the PA pressures. In obstructed TAPVC if a ductus is present, there may be right-to-left shunt indicating suprasystemic pressures in the pulmonary circuit.

Anomalous Drainage of Pulmonary Veins with Normal Connection Anomalous pulmonary venous drainage may be partial (PAPVD) or complete (TAPVD).248 Normally connected pulmonary veins may have flow directed to RA in the following conditions: • Sinus venosus ASD. • Large fossa ovalis ASD extending to posterior wall of LA. • Septum primum malposition defect.

Fig. 72.177: Two-dimensional echocardiography with color flow mapping in subcostal sagittal view showing a restrictive interatrial communication (arrow) with the turbulence across a patent foramen ovale in a case of total anomalous pulmonary venous connection (TAPVC). (LA: Left atrium; RA: Right atrium).

A

Septum Primum Malposition Defect Causing Partial or Total Anomalous Pulmonary Venous Drainage (Figs 72.180 and 72.181) This condition is usually associated with visceral heterotaxy, commonly with left isomerism and rarely with right isomerism.

B

Figs 72.178A and B: (A) Two-dimensional echocardiography with color flow mapping. Modified suprasternal short-axis view showing turbulence in the ascending vertical vein in a case of supracardiac total anomalous pulmonary venous connection; (B) Continuous wave Doppler tracing showing the continuous flow throughout the cardiac cycle with a mean gradient of 5 mm Hg. (Ao: Aorta; Innom: Innominate vein; VV: Vertical vein).


1677

Fig. 72.179: Two-dimensional echocardiography using subcostal coronal view with anterior tilt and color flow mapping showing the pulmonary venous confluence (PVC) draining to the coronary sinus. Patent foramen ovale (PFO) shunting is right to left (white arrow). There is flow acceleration at the junction of the pulmonary venous confluence and the coronary sinus (black arrow). (CS: Coronary sinus; RA: Right atrium).

A

B

Figs 72.180A and B: Two-dimensional echocardiography. Subcostal coronal view with color compare in a case of total anomalous pulmonary venous drainage showing a malaligned interatrial septum (arrow) resulting in the drainage of the pulmonary veins occurs into the right atrium (arrows). (LA: Left atrium; RA: Right atrium).

Fig. 72.181: Two-dimensional echocardiography. Apical fourchamber view showing malaligned interatrial septum (arrow) leading to total anomalous pulmonary venous drainage with normally connected pulmonary veins. RA is markedly dilated. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

1678


Echocardiographic pointers to the diagnosis of septum primum malposition defect are: • Deviation of septum primum toward anatomical LA • Absence of septum secundum • Normally attached pulmonary veins to anatomical LA • Interatrial communication in most posterior plane between posterior wall of LA and displaced septum primum • On color flow mapping, drainage of pulmonary veins to anatomical RA can be visualized. Number of pulmonary veins draining anomalously depends upon degree of malposition of septum primum. The views that can profile these anomalies are subcostal coronal, apical four-chamber, and parasternal long-axis.

or situs inversus). In contrast, the incidence of systemic venous anomalies in patients with heterotaxy syndrome exceeds 90%. Systemic venous anomalies are usually associated with other CHD.

Pulmonary Vein Stenosis

Persistent Left Superior Vena Cava

Pulmonary vein stenosis may be seen with TAPVC and needs to be keenly looked at but as an isolated case is a rare anomaly. It is usually associated with other lesions. Echocardiographic diagnosis is based upon a high index of suspicion in patients who present with features of primary pulmonary hypertension or pulmonary hypertension out of proportion to the heart defect. After 2D demonstration of pulmonary venous connection, color flow mapping must be done. On CFI, turbulent or mosaic flow pattern is the first indication of pulmonary vein stenosis in contrast to laminar flow in nonobstructed pulmonary veins. Pulsed and continuous wave Doppler interrogation reveals loss of phasic flow and/or increased velocity. The change in flow pattern depends upon the length of the obstructed channel and severity of stenosis. The condition has to be differentiated from increased pulmonary venous flow velocity associated with a large left-to-right shunt. In that case, there will be increased pulmonary vein velocity with preservation of phasic pattern, which touches the baseline. On 2D measurement, the stenosed pulmonary vein will be found to be of smaller caliber than normal.

ANOMALIES OF SYSTEMIC VEINS Systemic venous anomalies are rarely symptomatic in isolation, but are brought to notice on evaluation for other associated lesions. Their visualization may have a significant impact on the management of various lesions either directly or indirectly. Clinically significant abnormalities of the systemic veins are infrequent when the visceroatrial situs is lateralized (either situs solitus

Abnormalities of systemic veins may be classified into abnormalities involving:249–252 • SVC. • Retroaortic innominate vein • IVC and hepatic veins • Abnormalities of coronary sinus • Persistence of valves of embryonic venous sinus • Total anomalous systemic venous connection • Decompressive veins like levoatriocardinal vein.

Superior Vena Cava The commonest abnormality of SVC is persistence of LSVC draining to coronary sinus and then to RA. The prevalence of LSVC is 0.3% in general population, and 2 to 10% with congenital heart defects.253 LSVC exists with right superior vena cava (RSVC) in > 84% of cases and in >75% cases, a bridging innominate vein (“H” connection) is present. LSVC is located anterior to aortic arch and left PA, passes inferiorly, accepts hemiazygos vein, and then joins coronary sinus in the posterior AV groove. Hemodynamic significance: Although in isolation, it is of no hemodynamic significance, it poses difficulty with transvenous insertion of pacemaker leads; during an open heart procedure, separate venous cannulation is needed if the bridging vein is absent or very small and in patients undergoing univentricular correction. It has been noted that with persistent LSVC, the incidence of arrhythmias is higher and chances of preexcitation are ten times more than the general population, possibly because of abnormality of AV node and SA node. Congenital cardiac malformations that show a high frequency of persistent LSVC are juxtaposition of right atrial appendage (34%), AV canal defect (19%), mitral atresia (17%), and TOF (11%). With persistent LSVC, there is increased association of left-sided obstructive lesions and hypoplastic LV as the dilated coronary sinus impinges on mitral inflow during fetal life. An increase in the magnitude of left-toright shunt at the atrial level was found in patients with associated ASD. The presence of LSVC can be suspected on a chest radiogram based on a shadow along the left upper border of mediastinum.


1679

Echocardiography: 2D echocardiography in subcostal coronal, apical four-chamber, and PLAX views show the dilated coronary sinus as an oval structure, while subcostal coronal, and apical four-chamber views in posterior plane show the dilated coronary sinus in its whole length (Figs 72.182A to C). Other causes of dilated coronary sinus should be looked for if one does not find a LSVC, such as anomalous pulmonary venous drainage to coronary sinus, high right atrial pressure leading to passive congestion, and increased LCA flow leading to increased coronary sinus return. A dilated coronary sinus should be differentiated from pericardial effusion, which is not continuous with RA and inferior to the level of anterior mitral leaflet. Suprasternal short-axis view with left tilt shows LSVC, with or without the bridging innominate vein (Figs 72.183A and B). Coronary sinus in this view is seen as a crescentshaped structure receiving LSVC. On color flow mapping,

flow is seen away from the transducer in contrast to the vertical vein receiving pulmonary veins where flow is seen toward the transducer. In cases of poor echo windows, injection of agitated saline in left arm delineates the LSVC and coronary sinus.

A

B

C

Figs 72.182A to C: 2D echocardiography in a case of left superior vena cava (LSVC) to coronary sinus. (A) Apical four-chamber view with posterior tilt shows a dilated coronary sinus; (B) Apical fourchamber view shows a dilated coronary sinus in short axis; (C) Parasternal long-axis view showing the dilated coronary sinus (CS). (CS: Coronary sinus; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Left Superior Vena Cava to Coronary Sinus with Interatrial Communication and Defect in Wall of Coronary Sinus (see Fig. 72.34) This is a rare anomaly, known as Raghib syndrome. If a localized defect is present in the wall of coronary sinus, it is called partial unroofing of coronary sinus. More marked deficiency leads to LSVC draining to LA, also known as coronary sinus type of ASD. Here, the interatrial communication is coronary sinus ostium, which is located below and posterior to fossa ovalis. Rarely there may be

1680


A

B

Figs 72.183A and B: Two-dimensional echocardiography in suprasternal short-axis view with color compare showing a large left superior vena cava (SVC) draining to coronary sinus. (CS: Coronary sinus; LSVC: Left superior vena cava).

associated fossa ovalis or ostium primum ASD. Depending upon pressure difference between two atria, left-to-right or right-to-left shunt occurs. The patient may present with complication of right-to-left shunt with no significant murmur, such as cyanosis, paradoxical embolism, brain abscess, and stroke. Rarely, the ostium of coronary sinus may be atretic, causing whole of the LSVC flow into the LA. Rare cases of this in association with Lutembacher syndrome have been reported.254 Echocardiography: 2D echocardiographic findings are similar to LSVC drainage to coronary sinus. Special caution should be taken to define integrity of the wall of coronary sinus in case of cyanosis, because localized fenestrations are difficult to detect. In these circumstances, contrast echocardiography with saline injection in left arm shows filling of coronary sinus and LA almost simultaneously.

Left Superior Vena Cava to Left Atrium With completely unroofed coronary sinus, LSVC terminates in LA generally between left atrial appendage anteriorly and left upper pulmonary vein posteriorly. This anomaly rarely occurs in isolation, and is usually associated with heart defects like right isomerism. Echocardiography: Subcostal coronal, PSAX, and suprasternal short-axis views show connection of LSVC to LA. On color flow mapping, flow is seen toward the heart and away from the transducer. Contrast echo with saline injection in left arm demonstrates connection of LSVC to LA.

Absent Right Superior Vena Cava253,254 It is a rare anomaly of systemic veins and has been reported in 0.1% of patients undergoing cardiac catheterization. Either the right SVC is completely absent or represented by a fibrous vestigial cord. The right innominate vein drains to LSVC and then to coronary sinus. Embryologically, it is due to complete involution of right cardinal vein.

Clinical Significance Sinoatrial junction is poorly developed in these cases and patients, usually adults, may develop sick sinus syndrome requiring a pacemaker. Issues that make the diagnosis of absent right SVC important include: (a) implantation of transvenous pacemaker, (b) placement of transvenous pulmonary catheter for monitoring particularly without the usage of fluoroscopy, (c) systemic venous cannulation for extracorporeal membrane oxygenation (ECMO), (d) systemic venous cannulation for cardiopulmonary bypass, (e) partial or total cavopulmonary anastomosis, (f ) orthotopic heart transplantation, (g) endomyocardial biopsies, and (h) cardiac catheterization particularly for interventricular procedures. Special precaution should be taken at the time of openheart surgery to avoid damage to area around coronary sinus, and ligation of coronary sinus must be avoided. Echocardiography: Suprasternal short-axis view is especially important for determining whether right SVC is present or not, in addition to profiling of LSVC to coronary


sinus. In cases with absent right SVC, systemic veins appear to be mirror image of normal in suprasternal shortaxis view. Subcostal sagittal view shows absence of right SVC connecting to RA. Rarely, there may be absence of both the right and LSVC, and blood from arms, head, and upper torso is returned to the RA through the azygos vein and IVC mimicking chronic SVC obstruction.

1681

Anomalous drainage of the SVC to the LA is an extremely rare congenital cardiac malformation scantily reported in the English literature. Patients with this condition

usually present with cyanosis, clubbing, easy fatigability, features of polycythemia, and generally have no significant findings on cardiac examination. Some patients present with cerebrovascular accident. A common association is anomalous drainage of right upper pulmonary veins to the SVC1—an anomaly that should be actively looked for once anomalous RSVC drainage is diagnosed. Echocardiography as described above and contrast echocardiography are good modalities for the diagnosis; rarely, when in doubt, one may consider CT scan for the diagnosis. Surgical correction is warranted to prevent the risks of chronic polycythemia and systemic embolization. Surgery has had excellent short- and long-term outcomes. About 23 cases have been reported since the date of this anomaly.

A

B

Right Superior Vena Cava to Left Atrium (Figs 72.184 and 72.185)

Figs 72.184A and B: Two-dimensional echocardiography. Subcostal sagittal view with color compare showing the drainage of right superior vena cava (SVC; arrow) to left atrium. (LA: Left atrium; RA: Right atrium; SVC: Superior vena cava).

Fig. 72.185: Saline contrast study. Saline was injected into the right brachial vein and contrast echoes appeared in the left atrium followed by left ventricle. No contrast appeared in the right atrium and right ventricle, clearly showing communication of superior vena cava (SVC) to left atrium. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle; SVC: Superior vena cava).

1682


Aneurysm of Superior Vena Cava It occurs due to inherent weakness in the structure of venous wall. 2D echocardiography in subcostal sagittal and suprasternal short-axis views can demonstrate the aneurysmal dilatation of SVC. It is important to exclude the causes of undue dilatation of the SVC in cases like anomalous drainage of pulmonary veins (TAPVC/PAPVC to SVC) or abnormal fistulous communication to SVC.255

Retroaortic Innominate Vein (Fig. 72.186) Abnormal course of left innominate vein beneath the arch is named as retroaortic innominate vein and embryologically it is due to persistence of lower venous plexus between both anterior cardinal veins. Retroaortic innominate vein joins right SVC below the insertion of azygos vein. Clinical importance: This anomaly is of no hemodynamic consequences but during surgery, mobilization of right SVC is difficult. It should be especially visualized and differentiated from right PA on echocardiography. Most patients of retroaortic innominate vein have associated congenital cardiac malformations including TOF, truncus arteriosus, AVSD, heterotaxy syndrome, HLHS, pulmonary atresia with intact ventricular septum, and CoA. Echocardiography: Suprasternal short-axis view is best to demonstrate retroaortic innominate vein. On 2D

Fig. 72.186: Two-dimensional echocardiography. Suprasternal short-axis view with color flow mapping in a child with tetralogy of Fallot showing laminar flow in retroaortic innominate vein. (Ao: Decesnding Aorta; As Ao: Ascending aorta; Innom V: Innominate vein; RPA: Right pulmonary artery).

echocardiography and color flow mapping, this is seen as a horizontal channel crossing from left to right beneath the transverse arch superior to right PA. At times it can be mistaken for right PA. But on pulsed Doppler interrogation, the flow pattern in innominate vein will be venous and right PA will be arterial.

Abnormalities of Inferior Vena Cava Inferior Vena Cava Interruption Embryologically, it occurs due to failure of right subcardinal vein to develop properly and to anastomose with vitelline vein, resulting in enlargement of supracardinal system. Incidence of IVC abnormalities is 0.6% in patients with CHD, with 86% left isomerism, and it rarely occurs in isolation or with right isomerism. Clinical significance: This anomaly is of no physiological value but complicates cardiac catheterization, cardiac interventions, and single ventricular repair. Interrupted inferior vena cava with azygos continuation (Fig. 72.187):256 There will be absence of intrahepatic segment of IVC. Hepatic veins connect directly to RA or form a common hepatic vein to connect to RA. Venous return from lower body is via azygos vein, which connects to right SVC or hemiazygos which connects to innominate vein. Echocardiography: Subcostal sagittal view at the level of diaphragm shows anterior aorta, and a venous channel posterior and on right side of the spine. Subcostal sagittal

Fig. 72.187: Two-dimensional echocardiogram. Subcostal sagittal view with leftward tilt and color flow mapping showing an ascending venous channel (azygos continuation) posterior to aorta. (Ao: Aorta; AZ: Azygos; RA: Right atrium).


view shows ascending venous channel posterior to aorta (see Fig. 72.187) and hepatic veins entering RA, and no continuity is seen between hepatic vein and IVC. Interrupted inferior vena cava with hemiazygos continuation: In this defect, the abdominal or hepatic portion of IVC is absent, and hepatic veins connect to RA. Systemic venous return from lower body returns via hemiazygos vein, which connects to LSVC or coronary sinus or directly to RA. Echocardiography: Subcostal short-axis view at level of diaphragm shows aorta anterior to spine, and venous channel (hemiazygos vein) on left and posterior to the spine. Rarely, venous return from lower body is to both SVC via azygos vein on right side and hemiazygos vein on left side, and only hepatic vein continues to drain to the RA.

Inferior Vena Cava to Left Atrium Embryologically, it is impossible for IVC to connect to the morphological LA. It is the persistence of Eustachian valve directing the IVC blood to LA through foramen ovale or ASD. Clinically, the patient presents with features of rightto-left shunt. Rarely, with IVC type of sinus venosus ASD, right atrial connection of IVC may get atretic leading to a condition mimicking IVC connecting to LA. Echocardiography: Subcostal sagittal view shows inferior vena caval blood directed to LA or IVC directly connecting to LA. Saline contrast injection in femoral vein demonstrates filling of LA from IVC. Clinical importance: Clinical importance of hepatic veins connecting to LA lies in recognizing the condition prior to Fontan or Kawashima procedure, as these may lead to arterial hypoxemia and pulmonary arteriovenous fistulas. The visualization can be done by echocardiography, angiography, CT scan, or MRI.

Bilateral Inferior Vena Cava Bilateral venous systems contribute to the formation of the normal IVC and thus can explain the possibility of bilateral IVCs. Bilateral suprahepatic IVC are a frequent finding in cases of visceral heterotaxy syndrome with asplenia. These can rarely occur in normal visceral situs in which case left-sided hepatic veins drain into a normal coronary sinus. Bilateral infrarenal IVCs can occur in normal or abnormal visceral situs. Their visualization is particularly essential whenever contemplating the Fontan completion or interventional procedures.

1683

Abnormalities of Coronary Sinus257,258 Partial or Completely Unroofed Coronary Sinus It manifests itself as LSVC to LA. Rarely there is no LSVC.

Atretic Coronary Sinus Ostium Thin membrane-like tissue causes atresia of coronary sinus ostium. There is an alternate exit for coronary sinus blood to flow via LSVC, or at times an abberant connection with IVC. If there is no alternate exit, then the condition will be fatal because of myocardial infarction. Echocardiography on color flow mapping in suprasternal short-axis and PSAX views shows retrograde flow in LSVC (away from the heart and toward the transducer) if LSVC exists with normal connecting pulmonary veins.

Anomalous Connection of Hepatic Vein to Coronary Sinus This rare anomaly is of no hemodynamic significance. On 2D echocardiography with color flow mapping, hepatic venous flow to coronary sinus can be demonstrated in subcostal coronal view in the posterior plane. Clinical significance: It is characterized by progressive and severe cyanosis after Fontan completion if not recognized preoperatively.

Coronary Sinus Aneurysm/Diverticulum This rare condition has been reported in up to 8 to 10% of cases presenting with supraventricular tachycardia, undergoing radiofrequency ablation. Gold standard for the diagnosis is angiography, but diagnosis can be made by echocardiography if aneurysm is not very small. Echocardiography: Subcostal coronal and apical fourchamber views with posterior tilt show out pouching with a distinct neck arising from coronary sinus.

Prominent Venous Valves Venous Valves Venous valves such as Eustachian and Thebesian are prominent during fetal life and tend to involute after birth. Persistence can be in the form of small remnants. Pathological persistence of venous valves can cause partial or complete division of RA, that is, venous sinus-accepting

1684


systemic veins and true RA (right atrial appendage and vestibule of tricuspid valve), known as cor triatriatum dexter. Right-to-left shunt may occur across foramen ovale. There is high association with RV and PA hypoplasia in these cases. The incomplete regression of the embryonic right valve of sinus venosus may leave a fenestrated or unfenestrated membrane in the RA that should be considered a normal benign variant of the so-called Chiari network. Echocardiography in subcostal sagittal and coronal views shows persistence of an echodense structure in RA and on color flow mapping, right-to-left shunt across foramen ovale may be seen. This anomaly needs to be differentiated from right atrial myxoma. Sometimes a very prominent Chiari network may cause difficulty during atrial septal device closure.

Total Anomalous Systemic Venous Drainage It is an exceptional form of CHD scantily described in the literature. All systemic venous flow, including the RSVC, persistent LSVC, IVC, and coronary sinus drain abnormally into the LA. This disorder is usually associated with AV canal defects, common atrium, ASD, VSD, and heterotaxy. It is a very rare disorder and a total of only 11 cases have been reported so far including three of our unpublished cases. Surgical correction is often difficult and complicated. Total anomalous systemic venous drainage can be classified into two types; accordingly, the type of vena cava cannulation will vary. In type I, the IVC is not interrupted and conventional cardiopulmonary

bypass can be created. In type II, the IVC is interrupted, and single cannulation of the SVC and conventional cardiopulmonary bypass can be achieved. In this case, hepatic veins can be cannulated with a small cannula after excision of the atrial septum or an intracardiac extractor is used to manage the blood flow. Most of these cases including the three seen by us have been associated with heterotaxy syndromes.

Decompressive Venous Channels Levoatrial cardinal vein: This is a persistence of connection of pulmonary veins to systemic veins, which occurs due to severe left-sided obstruction and restrictive interatrial communication; rarely does it occur in isolation. The levoatriocardinal vein arises directly from LA or from a pulmonary vein and connects to right SVC, innominate vein, or jugular vein. Echocardiography: Subcostal coronal PSAX, and suprasternal views can demonstrate the levoatriocardinal vein. On color flow mapping, flow is seen away from the heart and toward the transducer with normally connecting pulmonary veins. Decompressive venous channels are especially common after Glenn shunt surgery for a univentricular pathway. These can be suspected on echocardiography and well profiled either by angiography, CT, or MRI. They can be tackled either by catheterization (vascular plugs or coils) or surgically. It is important to occlude the channel before determining the pulmonary pressures in preFontan catheterization.

PART 10: IMAGING OF CORONARY AND PULMONARY ARTERIES CORONARY ARTERY ANOMALIES Coronary anomalies cause 10 to 19% of sports-related deaths in athletes and 1.2% of non–sports-related deaths in young individuals.259–264 In 69% of the population, there is a dominant RCA system, while in 11%, the LCA is dominant, thereby giving rise to the posterior descending coronary artery, and in 20% there is codominance.263 Interestingly, a significant number of patients with bicuspid aortic valves or aortic stenosis (20–57%) have left-dominant systems and a short left main coronary artery.265–267 Also, separate origins of the LAD and left circumflex coronary arteries occurs in about 1% of population and is more frequent

with bicuspid aortic valves. Even though various coronary anomalies cannot always be identified by echocardiogram, it is imperative to identify the origin of coronaries on every echocardiogram. Failure to identify normal coronary origins from the mid-portions of the left and right coronary sinuses will alert one to the possibility of an anomalous coronary origin. The origin and proximal course of the coronaries are identified in the PSAX views recorded from a high left parasternal window using a high frequency transducer (Figs 72.188A to D). The origin of left main coronary artery from the left coronary sinus, bifurcation of left main coronary artery to LAD, and left circumflex and origin


A

B

C

D

1685

Figs 72.188A to D: Two-dimensional echocardiography with color flow mapping showing normal coronaries. (A) Parasternal short-axis view showing the right coronary artery (RCA) and the left anterior descending artery (LAD, arrow); (B) Color flow mapping showing the course of LAD; (C) Parasternal short-axis view showing the origin of the right coronary artery (arrow); (D) Color flow mapping showing right coronary artery (RCA). (Ao: Aorta; PA: Pulmonary artery; RVOT: Right ventricular outflow tract).

of the RCA from the right coronary sinus will be noted in this view. On gentle clockwise rotation of the probe, a longer length of the LAD artery and its branches will be noted. Similarly, a gentle counterclockwise rotation of the probe should be able to show a longer length of the RCA. Numerous coronary artery abnormalities are described in normal as well as abnormal hearts. We will only focus on clinically and significantly relevant abnormalities.

Anomalous Pulmonary Origin of Coronary Artery268–273 Anomalous origin of the left main coronary artery (the LAD, circumflex branch) from PA (ALCAPA) or RCA

(ARCAPA) from the proximal PA or more distally from the proximal right PA is a rare congenital anomaly with serious consequences. In such cases, symptoms appear within a few days of birth, and death may follow within a few weeks; it is compatible with life only if associated with pulmonary hypertension or significant collaterals from the other coronary artery system. The heart develops normally in fetal life. After birth, as long as the pulmonary arterial pressure remains at or near systemic levels, the left ventricular myocardium is supplied by the anomalous artery and remains well perfused. As pressure in the PA falls postnatally, perfusion of the LV becomes inadequate, as the coronary artery pressure falls below the left ventricle end-diastolic pressure (LVEDP). The consequence of this circulatory handicap is a decrease

1686


of left ventricular function, due to myocardial ischemia. At the same time, the ischemic myocardium is being perfused increasingly by a developing set of collateral vessels from the RCA, which are present normally. Those with perfectly distributed collateral arteries before the PA pressure falls escape with minor ischemic damage of the left ventricular myocardium, which is well perfused, and normal in form and function; this type is often diagnosed in adolescence or adulthood. Any case of LV dysfunction should be evaluated for this anomaly. It is important to remember that any condition wherein the PA pressures are high such as high pressure shunt lesions (VSD or

Fig. 72.189: Parasternal short-axis view showing a dilated right coronary artery in a case of anomalous left coronary artery origin from the pulmonary artery. (Ao: Aorta; RCA: Right coronary artery).

A

ductus) may not lead to the above picture, and in fact may even show a normal coronary flow pattern on color Doppler echocardiography. Thus, the diagnosis can be easily missed if the origin of the coronary arteries is not profiled properly leading to a catastrophic event after closure of these defects.274,275 It is, therefore, imperative to recognize the entity by imaging the coronary arteries on 2D echocardiography. Echocardiographic features of the anomaly include: • Dilated RCA and absence of LCA from left sinus (Fig. 72.189). • Anatomical delineation of the anomalous origin of LCA from PA is done by 2D echocardiography in PSAX view at the level of great vessels. The common site of origin of LCA from PA is from the posterior-facing sinus. Very rarely, the anomalous LCA may have its origin from the other nonfacing anterior sinus of PA. Rare instances of origin of LCA from main PA trunk or right PA have been reported, often missed on echocardiogram and diagnosed by other means. Echocardiographic identification of the origin has a major relevance to surgical strategy, since establishment of dual coronary supply is easily achieved only if the coronary artery can be mobilized to the aorta (Figs 72.190A and B). • Detection of left-to-right shunt in PA. • Color Doppler demonstration of reversal of flow from LCA (Figs 72.190A and B) to PA. • Left ventricular dilatation and reduced systolic function; surgical risk stratification depends on left ventricular function.

B

Figs 72.190A and B: Two-dimensional echocardiography. (A) Shows the origin of the left main coronary artery (marked by the arrow) from the pulmonary artery; (B) Color flow mapping shows flow reversal in the coronary artery with left anterior descending artery (LAD) showing blue color flow signals indicative of flow toward the pulmonary artery in a case of anomalous origin of left coronary artery from pulmonary artery (ALCAPA). (Ao: Aorta; PA: Pulmonary artery).


A

1687

B

Figs 72.191A and B: Two-dimensional echocardiography. Apical four-chamber view showing the sclerosed papillary muscle (arrow) in a case of anomalous left coronary artery from pulmonary artery; (B) Color flow mapping showing mild mitral regurgitation. (LA: Left atrium; LV: Left ventricle).

•

•

•

Ischemic mitral regurgitation (Figs 72.191A and B). In all infants and children with unexplained left ventricular dilatation and mitral regurgitation, anomalous origin of LCA from PA should be considered as a possible etiology and actively excluded. Scarring of papillary muscles of the LV as a result of myocardial ischemia, which acts as a very strong clue in infants with severe left ventricular dysfunction to the etiology for the myocardial dysfunction. Color Doppler demonstration of myocardial collateral flow in the interventricular septum through septal collaterals from RCA to LAD artery (Fig. 72.192).

Anomalous Origin of Right Coronary Artery from Pulmonary Artery276–278 Right coronary artery (RCA) origin from the pulmonary trunk (ARCAPA) is rarer than anomalous origin of LCA from the PA. These patients can present with left ventricular dysfunction at a later age as compared to patients of ALCAPA (Fig. 72.193). The coronary flow to the interventricular septum is compromised. In infants and children presenting with left ventricular dysfunction, the origin of RCA should also be looked for carefully. If it is not seen from the aortic sinuses, its origin from the PA is a possibility. The other clue could be the presence of collateral flow in the interventricular septum with normal LCA. Various coronary abnormalities of coronary origin have been described.279-287 Few important ones are discussed here.

Fig. 72.192: Two-dimensional echocardiography. Modified parasternal short-axis view with color flow mapping in a case of anomalous left coronary from pulmonary artery showing a dilated right coronary artery (RCA; arrow) with multiple collaterals from right coronary artery (arrow). (Ao: Aorta).

Tangential Origin of Coronary Artery Normal coronary artery origin is from the mid-portions of the left and right coronary sinuses of the aorta. The coronaries are given off perpendicular to the aortic wall. In some cases, coronary arteries can arise from other areas, namely high origin or commissural origin, arising from the noncoronary sinus, or arising tangentially instead of perpendicularly. The tangential origin is associated with a slit-like coronary orifice. This can be suspected on careful echocardiographic profiling of coronary origin in PSAX view using a high frequency transducer.

1688


Fig. 72.193: Two-dimensional echocardiography. Parasternal short-axis view showing anomalous origin of the right coronary artery from the pulmonary artery (arrow). (Ao: Aorta; PA: Pulmonary artery).

Pathologists consistently observe a fibrous ridge at the ostium of tangentially oriented ectopic coronary arteries. Such ridges are often said to have potentially catastrophic consequences. Nevertheless, plaque activation or rupture is seldom documented, even on examination of the histological anatomy. High origin and commissural origin of coronary arteries are also sometimes associated with the same anatomy. In these anomalies especially high origin of coronary arteries above the aortic sinuses, abnormal fluid dynamics have been documented to cause significantly attenuated blood flows.

CORONARY ARTERIOVENOUS FISTULA (FIGS 72.194A TO C) Coronary arteriovenous fistulas are present in 1 of 50,000 live births (0.002% of the general population) and are visualized in 1 of 500 patients undergoing catheterization (0.2–0.25%).288,289 The etiology of these lesions may be congenital or acquired; the latter may be broken down into infectious, traumatic, and iatrogenic. Iatrogenic causes may be further subdivided as after surgery, catheterization, angioplasty, or endomyocardial biopsy. We will be discussing congenital coronary arteriovenous fistulae only. Coronary arteriovenous fistula involves RCA in 60%, LAD artery in 25%, and left circumflex artery in 15% of patients. Rarely it involves more than one coronary artery.

The common sites of drainage are RV in 30%, RA in 25%, and PA in about 20%, rarely into LA, LV, coronary sinus, or SVC. The termination may be a single or multiple orifices. Echocardiographic features of coronary arteriovenous fistula include (a) dilated proximal coronary artery, (b) continuous color Doppler flows with high velocity rather than normal velocity diastolic flows seen in normal coronary arteries, (c) delineation of the course of the fistula to its termination, unless it is tortuous when it may not be possible to track it fully, (d) high-velocity turbulent flow at the site of drainage, and (e) volume overload of cardiac chambers depending on the magnitude of left-toright shunt through the fistula. Rarely, the fistula opens into a large sac (fifth cardiac chamber), which opens into one of the cardiac chambers. Echocardiography provides good details of fistula in many patients. Angiographic classification of surgical relevance is proposed by Sakakibara.288 Type A (proximal type)—proximal coronary segment dilated to the origin of fistula, distal end normal; and type B (distal type)—coronary artery dilated over its entire length, terminating as a fistula in the right side of the heart.

CORONARY ANEURYSMS Aneurysms are defined as dilations of a coronary vessel 1.5 times the adjacent normal coronaries. The aneurysm can be saccular or fusiform, fusiform being the most common. Aneurysms may be congenital or acquired, the latter may be further subdivided into atherosclerotic, Kawasaki disease, traumatic, iatrogenic (surgical, after angioplasty, catheterization, or endomyocardial biopsy), infectious, and systemic diseases (polyarteritis nodosa, syphilis, Ehlers–Danlos syndrome, Marfan disease, and scleroderma).

Kawasaki Disease Kawasaki disease is the commonest disease associated with coronary aneurysms in the pediatric age group. Moderate coronary involvement with aneurysms is present in 12.8 to 25% of patients with untreated Kawasaki disease; the incidence of coronary involvement reduces to one fifth after timely intravenous gamma globulin therapy. The following definitions pertaining to Kawasaki disease are generally accepted in the literature: segmental stenosis—a braid-like lesion with multiple tortuosities of the vessel,


1689

A

B

C

Figs 72.194A to C: A 2-year-old child with coronary arteriovenous (AV) fistulae from right coronary artery (RCA) to right atrium (RA). (A) Parasternal short-axis view showing a dilated right coronary artery (arrow) at its origin; (B) Apical four-chamber view with posterior tilt showing the dilated and aneurysmal right coronary artery in the atrioventricular (AV) groove (arrow); (C) Apical four-chamber view showing the aneurysmal RCA with small opening (arrow) in the right atrium. (Ao: Aorta; LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; RV: Right ventricle).

which represents recanalization of an occlusion; localized stenosis—a discrete, wedge-like narrowing at the inlet or outlet of an aneurysm; ectasia—1.5 times larger than normal adjacent coronaries; dilation/small aneurysm— up to 3 mm (± irregular lumen); aneurysms—4 to 8 mm; and giant aneurysms—greater than 8 mm. On echocardiography, proximal parts of left main, LAD artery, left circumflex, and RCA can be defined from parasternal short- and long-axis view at the level of great vessels as described earlier. Apical four-chamber view with posterior tilt to the right side defines the distal part of RCA in right AV groove and to left side profiles circumflex

artery in the left AV groove. The circumflex artery can also be profiled from long-axis view with posterior tilt and subcostal five-chamber view.

Atresia of Left Main Coronary Artery290 Atresia of left main coronary artery with lack of luminal continuity from aortic root to LCA is associated with collaterals from the RCA through septal branches. This mimics the septal collaterals of anomalous origin of LCA from PA on echocardiography, but there will be no reverse flow pattern seen in LCA and no left-to-right shunt in PA .

1690


PART 11: ECHOCARDIOGRAPHIC EVALUATION OF AORTIC ARCH AND ITS ANOMALIES Aortic arch anomalies constitute an important subgroup of cardiac lesions, which may occur in isolation or in association with other intracardiac defects. The thrust in the present century is on precise, noninvasive imaging of the aortic arch and its principal branches in order to plan timely appropriate treatment. Echocardiography is an important noninvasive diagnostic modality in diagnosing, monitoring the progression of lesions, and planning timely intervention and followup after intervention in these lesions. The suprasternal notch291 views are the most important echocardiographic views in diagnosis of aortic arch anomalies. In neonates and infants, subcostal, high parasternal and apical views can also provide imaging of the aortic arch, but these views permit imaging only up to the origin of first branch and these windows are inadequate in older children and adults. PLAX and short-axis views can image only the proximal aorta and hence have limited usefulness. 2D echocardiographic imaging of the arch: The arch of aorta is best imaged from suprasternal view.291 For the suprasternal views, the transducer is placed in the suprasternal notch and aligned as closely parallel as possible with the sternum. In order to gain access to the suprasternal notch, the patient is positioned supine with a pillow beneath the shoulders to extend the neck without producing tension on the sternocleidomastoid muscles. The patient’s head is turned to the left or right so that the chin does not prevent adequate placement of the transducer in the suprasternal notch. The ascending aorta, transverse, and descending thoracic aorta are best visualized in the suprasternal long-axis view. To obtain good suprasternal long-axis view, the transducer is placed in the suprasternal notch with the plane of ultrasound beam oriented between the right nipple and the left scapular tip. Suprasternal short-axis view is used to define the branching pattern and side of arch. To obtain suprasternal short-axis view, the transducer is placed in horizontal position in suprasternal notch and should be turned to right to define bifurcation of first arch vessel with left aortic arch, and to left with right aortic arch. Aortic arch anomalies can be classified as follows: • Abnormal formation of aortic arch • Coarctation and its most severest form, that is, interrupted aortic arch • Aortic aneurysms.

ABNORMAL FORMATION OF ARCH The subgroup of aortic arch abnormities resulting from abnormal formation of aortic arch includes: • Mirror image right-sided aortic arch • Vascular rings • Cervical aortic arch • Double aortic arch.

Right Aortic Arch292–297 Left and right aortic arch refer to which bronchus is crossed by the arch, not to which side of the midline the aortic root ascends. Practically, the sidedness of the aortic arch is determined indirectly with echocardiography or angiography by the branching pattern of the brachiocephalic vessels. As a rule, the first arch vessel gives rise to the carotid artery opposite the side of the arch. The very rare cases of retroesophageal or isolated innominate artery are exceptions to this rule. But by far the more common source of error in the use of this rule is the difficulty in deciding which of the two carotid arteries the first one is. A more reliable rule but one that may be difficult to apply with ultrasound imaging is that retroesophageal vessels or isolated vessels, that is, arising only from a ductus or ligamentum (without connection to the aorta), are always opposite the side of the aortic arch. The incidence of right aortic arch among patients with tetralogy of Fallot has been reported to be anywhere from 13 to 34%.292 The incidence in truncus arteriosus is generally higher than in tetralogy. An overall incidence of 8% in patients with d-TGA with intact septum, and 16% in those with transposition, VSD and pulmonary stenosis has been reported.293 The normal left-sided arch is viewed in suprasternal long-axis view with the plane of ultrasound beam directed between the right nipple and left scapular tip with the first branch being the right innominate artery, which bifurcates into right subclavian and right carotid artery. The diagnosis of right-sided arch is suspected when the transducer has to be rotated counterclockwise between the left nipple and right scapular tip in order to visualize the arch. Tilting the transducer anteriorly and posteriorly from suprasternal long-axis view images the relation of transverse aorta with the tracheal rings and tracheal air column, that is, in right aortic arch the transverse aortic arch is seen to the right


of trachea. Right-sided aortic arch is further confirmed if the first vessel courses leftward and then bifurcates, which is seen in suprasternal short-axis view. If the first arch vessel courses to left but does not bifurcate, then there are chances of more complex malformations being present such as an aberrant left subclavian artery as well as increased chances of vascular ring formation.

1691

A vascular ring is an aortic arch anomaly in which the trachea and esophagus are completely surrounded by vascular structures. The vascular structures need not be patent. Vascular rings are formed when an aortic arch abnormality forms a ring of tissue encircling the trachea and esophagus. The presence of vascular ring anomaly is highly probable if the suprasternal views demonstrate arch anatomy other than a left arch with a normal right innominate artery or a right arch with mirror image branching. These rings are recognizable by the presence of one of three “d”s opposite the side of the aortic arch: diverticulum, dimple, or descending aorta. A diverticulum is a large vessel arising from the descending aorta that gives rise to a smaller caliber vessel with a sudden taper. A dimple is a tapered, blindly ending out pouching from the aorta. Descending aorta opposite the side of the aortic arch refers to its location in the upper thorax. These three “d”s form the vascular ring only when connected by a

ligamentum arteriosum or an atretic segment of aortic arch which cannot be profiled by 2D echocardiography. The common type of vascular ring anomalies include: • Left aortic arch with aberrant right subclavian artery (Fig. 72.195) and right duct or ductus ligament • Right aortic arch with aberrant left subclavian artery and left duct or ductus ligament • Right aortic arch with retroesophageal segment and left descending aorta, and • Double aortic arch. On echocardiography, diagnosis of left aortic arch with aberrant right subclavian or right aortic arch with aberrant left subclavian is possible if there is failure to demonstrate bifurcation of the first arch vessel. Demonstration of origin of fourth arch vessel, that is, aberrant subclavian is difficult by echocardiography, and definition of detailed anatomy requires spiral CT or MRI. Double aortic arch can be directly visualized by performing a standard long-axis view and rotating the transducer 30° to 45° counterclockwise (Fig. 72.196). In suprasternal short-axis view, evidence of a double circle with tracheal ring in center is suggestive of double aortic arch. In some cases, even subcostal views may demonstrate aorta bifurcating into two arches a few centimeters above the aortic valve. Demonstration of both arches requires use of views for left and right aortic arch. Usually, one arch dominates and the other is hypoplastic or atretic. Origin of arch vessels should be defined from suprasternal views.

Fig. 72.195: Two-dimensional echocardiography in suprasternal long-axis view showing the aberrant right subclavian artery (arrow) arising distal to the origin of the left subclavian artery. (Ds Ao: Descending aorta; TA: Transverse arch).

Fig. 72.196: Two-dimensional echocardiography. Suprasternal short axis in a case of double aortic arch showing the right and left components of the arch. (R: Right component of the double aortic arch; L: Left component of the double aortic arch).

Vascular Rings

1692


Cervical Aortic Arch298–301 In this anomaly, the arch is found above the level of the clavicle. There are two main subcategories of cervical arch: • Those with anomalous subclavian artery and vascular ring, with either descending aorta contralateral to the arch or retroesophageal diverticulum. • Those with a virtual normal branching pattern. Cervical aortic arch presents as a pulsatile mass and may be identified from the suprasternal long-axis view. It requires placement of transducer onto the neck over the pulsatile mass, and suprasternal long-axis view will then show a long ascending aorta.

of coarctation anatomy in most patients. High quality ultrasound images can be obtained in infants but may be somewhat difficult to obtain in larger children and adolescents.

CoA is narrowing of the aorta, most commonly at the junction (isthmus) of the arch of aorta and descending thoracic aorta. CoA occurs in approximately 6 to 8% of patients with CHD.301 True CoA results from a localized thickening of aortic media, which protrudes into the lumen of the aorta from the posterior and lateral walls and obstructs blood flow (Figs 72.197A and B). Although usually a discrete lesion, coarctation may consist of a long stenotic segment or tubular hypoplasia. Very rarely, the narrowing may be located in the abdominal aorta (Fig. 72.198). 2D echocardiography and Doppler studies (Figs 72.199A and B) provide an accurate, noninvasive assessment

Echocardiographic objectives: • Is there coarctation? • Is there discrete stenosis or long segment stenosis? • Is there arch hypoplasia? • Branching pattern of arch. • Are there associated cardiac anomalies, in particular, bicuspid aortic valve, left-sided obstructive lesions such as aortic stenosis, subaortic membrane, mitral valve disease, or hypoplastic left heart? • Left ventricular hypertrophy. • Ventricular function. The echocardiographic examination using the suprasternal long-axis view provides an image of the entire arch, with the area of coarctation seen near the origin of left subclavian artery, that is, juxtaductal CoA (Figs 72.200A and B). On 2D echocardiography, it is seen as a prominent posterior shelf with significant coarctation. When imaging the arch, one must be absolutely certain that the entire arch is imaged, particularly in the region of the left subclavian artery. The diagnosis can be missed with inadequate imaging in this area. Type of coarctation may either be a long segment narrowing or, more commonly short segment obstruction caused by posterior endothelial shelf projecting into the aorta (Figs 72.197A and B). There may be associated

A

B

COARCTATION OF AORTA (CoA)302,303

Figs 72.197A and B: Two-dimensional echocardiography with color compare. (A) Suprasternal long-axis view with color compare in a child of coarctation of aorta showing tiny posterior (arrow) shelf with flow acceleration; (B) Suprasternal long-axis view with color compare in another case of coarctation of aorta showing a prominent posterior shelf (arrow) with significant turbulence in the arch starting from the coarctation region. (As Ao: Ascending aorta; Ds Ao: Descending aorta; TA: Transverse arch).


1693

Fig. 72.198: Arch measurements. Suprasternal long-axis view of the ascending aorta and aortic arch showing the measurements to be made. (A: Ascending aorta; B: Transverse arch; C: Isthmus; D: Narrowest segment; E: Descending aorta).

A

B

Figs 72.199A and B: Continuous wave Doppler signals across the coarctation of aorta. (A) Demonstrates mild coarctation of aorta with early diastolic spill and a gradient of 31 mm Hg; (B) Shows severe coarctation of aorta with pan-diastolic flow and a gradient of 61 mm Hg.

A

B

Figs 72.200A and B: Two-dimensional echocardiography. Suprasternal long-axis view showing interruption of the aortic arch distal to the left subclavian artery with arch hypoplasia (arrow); (B) Represents suprasternal long-axis view showing interruption of the arch of aorta (arrow) between the carotid arteries (type C). (As Ao: Ascending aorta; Ds Ao: Descending aorta; TA: Transverse arch).

1694


hypoplasia of transverse arch. In the region of the ductus arteriosus, an anterior shelf may normally exist just proximal to the aortic origin of ductus. It is important not to mistake this for the coarctation shelf. The measurements which should be taken in a case of coarctation are shown in Figure 72.198. Certain intracardiac findings suggest the possibility that a CoA may exist before the arch is imaged. Left ventricular outflow obstructive lesions, significant right or left ventricular hypertrophy without obvious explanation, and the absence or reduced pulsation in descending aorta as imaged from the subcostal window suggest the possibility of CoA.

Doppler Feature of Aortic Coarctation303–311 Doppler echocardiography can assist in determining the hemodynamic severity of coarctation. First, color flow imaging of the descending aorta is performed, looking for a high-velocity (turbulent flow) jet in the region of coarctation. Once such a jet is imaged on color Doppler examination, the continuous wave Doppler beam is directed into the area of turbulent flow (Figs 72.199A and B). The Doppler recording usually shows a high velocity jet with antegrade flow extending well into diastole. This flow pattern is characteristic of severe obstruction in a vessel with a pressure gradient extending into diastole. As the severity of obstruction increases, the pressure above the coarctation remains elevated for a longer period of the cardiac cycle, and thus, the jet extends into the entire diastole. From the peak velocity of the jet (V2) and the simplified Bernoulli equation (P = 4V22), the peak instantaneous pressure gradient across the coarctation can be calculated. Many patients with CoA have multiple left heart obstructive lesions (e.g. bicuspid aortic valve, valvular aortic stenosis, subaortic membrane, etc.) that can lead to an increased peak flow velocity proximal to the coarctation jet. If the peak velocity proximal to the coarctation (V1) exceeds 1 m/s recorded by pulsed Doppler echocardiography from suprasternal long-axis view, then the expanded Bernoulli equation (P = 4[V22 − V12]) should be used to avoid a significant overestimation of the peak gradient. Even then the gradient across the coarctation may be unreliable. The gradient depends on the shape and length of the coarctation segment, the patient’s cardiac output, and the presence and extent of collateral flow. Thus, the gradient can over- or underestimate the severity of coarctation. If the left ventricular ejection fraction is low, there can be underestimation of severity of coarctation by Doppler. In such cases, a slow dP/dt of the systolic

signal, diastolic spill, lumen size at the coarctation site, left ventricular hypertrophy, and PA pressures help in the final diagnosis. The coarctation area can also be profiled from high PSAX view with counterclockwise tilt. This view opens up the coarctation area and descending aorta below the left subclavian artery. In patients with inadequate suprasternal widow, pulsed Doppler echocardiographic recordings from the proximal abdominal aorta can be useful. It shows a continuous antegrade flow signal with no evidence of flow reversal or cessation, the time of peak velocity is prolonged, and the mean acceleration rate is decreased.

INTERRUPTION OF AORTIC ARCH Arch interruption represents the most severe form of coarctation, which can be demonstrated from suprasternal views.312,313 Interruption of arch of aorta is generally associated with complex CHDs like AV canal defect, d-transposition of great arteries with or without tricuspid atresia, Taussig–Bing anomaly, and congenitally corrected transposition apart from VSD, PDA, AP window, subaortic stenosis, bicuspid aortic valve, and mitral stenosis. The interruption of arch of aorta may involve only a short segment or a long segment with a long distance between the proximal and distal segments of the aorta. Celoria and Patton312 classified them as type A if the interruption was distal to the left subclavian artery, type B if between carotid and subclavian arteries, and type C if between carotid arteries. However, these types may be further subcategorized313 and definitions generalized to include both right and left arch patterns as in Table 72.16. Type B arch interruption is the most common form and is usually associated with conotruncal anomalies and normally aligned great arteries in which there is a large malalignment type of VSD associated with posterior displacement of the infundibular septum and subaortic obstruction. Type B interruption is also commonly seen in association with DiGeorge syndrome. Type A interruption tends to occur with aorticopulmonary septal defect and intact ventricular septum and in a large group of patients with transposition of great arteries. On 2D echocardiography, suprasternal views show ascending aorta continuing to at least one of the arch vessel. In type A arch interruption, all three branches are seen proximal to interruption; in type B interruption, first and second branches are seen proximal to interruption; and in type C interruption, only the first branch, that is, innominate artery is seen arising proximal to interruption.


1695

Table 72.16: Classification of Interrupted Aortic Arch

Type A: Interruption distal to the left subclavian artery •

Without retroesophageal or isolated subclavian artery

• With retroesophageal subclavian artery •

With isolated subclavian artery

Type B: Interruption between second carotid and ipsilateral subclavian artery •


• With retroesophageal subclavian artery (i.e. both carotid arteries proximal, both subclavians distal) •


Type C: Interruption between carotid arteries •


• With retroesophageal subclavian artery •


Descending aorta is relatively dilated with ductal continuation to descending aorta, which is well profiled in suprasternal long-axis and high PSAX views. Care should be taken to ensure that the ductus arteriosus connecting the main PA to descending aorta (ductal arch) is not mistaken for the true arch. Color flow mapping confirms the findings and as systemic flow is duct-dependant, patency of duct or any restriction of duct should be defined by color flow mapping. Pulsed Doppler is used to assess the gradient across the ductus. Sometimes, restriction of ductus arteriosus can mimic CoA, and that should be clearly defined. In patients with suprasystemic PA pressures, there can be turbulent right to left flow across the ductus.

AORTIC ANEURYSM The third important subgroup of aortic arch anomalies includes aneurysms of the aorta. Aneurysm of a vessel is defined as a dilated segment > 50% in diameter as compared to the proximal segment. In pediatric age group, in contrast to adults, aneurysm of ascending aorta is more common than descending aorta. Annuloaortic ectasia is defined as aneurysmal involvement of annulus and aortic root, in addition to ascending aorta. In children, aneurysmal dilatation of proximal aorta can be caused by conditions associated with medial degeneration of the aorta such as Marfan syndrome, Ehlers–Danlos syndrome, Turner syndrome, in association with bicuspid aortic valve, and idiopathic; however, some types of infectious disease like bacterial endocarditis can also result in aneurysm formation. Aneurysm of proximal aorta is usually easily

recognized from the parasternal long-axis, PSAX, subcostal coronal, and suprasternal long-axis views. Aneurysmal involvement of descending aorta usually occurs secondary to previous surgical or catheter intervention such as surgical repair of CoA or balloon dilatation of coarctation. Chances of aneurysmal formation are much less after stent deployment for CoA. Descending aorta aneurysm can be defined from suprasternal long-axis, suprasternal shortaxis (aneurysm from lateral wall), and subcostal sagittal views in infants and children. The echocardiographic measurements are helpful in diagnosing and assessing the progression of the disease. Besides visualization of the aneurysm, echocardiographic examination should also focus on detecting complications of aneurysms such as compression of adjacent structures and fistula formation. Transthoracic echocardiography is a useful modality in diagnosis, monitoring, and planning appropriate nonsurgical/surgical management and in postintervention follow-up of these patients. Transthoracic echocardiography has limitations in grown-up children because of suboptimal acoustic windows and in the postintervention period. In such patients, transesophageal echocardiography spiral CT, or MRI can demonstrate these lesions.

Anomalous Origin of Branch Pulmonary Artery from Ascending Aorta (Fig. 72.201)314,315 Anomalous origin of one PA from ascending aorta used to be known as “hemitruncus” (This terminology is not used now).

1696


Echocardiographic diagnosis of origin of PA from ascending aorta depends upon demonstration of: • Absence of normal bifurcation of main PA • RVOT continuing as one PA • Origin of one PA from ascending aorta. Subcostal coronal view with anterior tilt, PLAX view, and suprasternal long-axis and short-axis views show origin of a branch pulmonary artery (PA) from ascending aorta. PSAX view profiles main PA continuing as one PA and with change in the plane of ultrasound, origin of another PA from ascending aorta can be profiled. This is differentiated from truncus arteriosus, by demonstrating two separate semilunar valves, and from APW by demonstrating PA bifurcation in the latter defect. Fig. 72.201: Two-dimensional echocardiography in modified suprasternal short-axis view showing the origin of the left pulmonary artery from the ascending aorta. (Ao: Aorta; LPA: Left pulmonary artery; RPA: Right pulmonary artery).

This anomaly needs to be differentiated from APW, truncus arteriosus, and discontinuous pulmonary arteries with one PA supplied from ductus or a collateral, as in the setting of VSD with pulmonary atresia. By far, the more common form is anomalous origin of the right PA, seen in 82% of 108 cases excellently reviewed by Kutsche and Van Mierop.314 The anomalous right PA usually arises from the posterior aspect of the ascending aorta close to the aortic valve. Less commonly, it originates from the lateral ascending aorta just proximal to the innominate artery. PDA and aorticopulmonary septal defect are commonly associated with anomalous origin of the right PA; other cardiovascular anomalies are rare. In contrast, TOF and aortic arch anomalies, for example, right aortic arch and anomalous origin of the subclavian artery, are common in anomalous origin of the left PA. An association with DiGeorge syndrome, frequently noted with persistent truncus arteriosus, is not seen with anomalous origin of a PA from the ascending aorta.

Pulmonary Artery Sling316–318 Pulmonary artery sling is a rare anomaly in which the left PA arises from right PA and passes posteriorly between trachea and esophagus to the left side. Due to this course, left PA forms a sling, encircling trachea, anteriorly main PA, right and posteriorly left PA, and on the left ductus arteriosus or ductus ligament. PA sling compresses the right bronchus and trachea from the posterior aspect as it courses to left and posterior after its origin from right PA. The child presents with respiratory distress and stridor in infancy. This anomaly should be looked for in infants presenting with stridor and respiratory distress. The anomaly could first be suspected if PSAX view does not show normal main PA bifurcation, main PA seems to continue as right PA , and on tilting the transducer inferiorly and to left, left PA can be profiled arising from right PA . After origin, left PA passes posterior to echogenic shadow of trachea. This finding can also be defined from high PSAX view and modified suprasternal short-axis view. With the use of color flow mapping, it becomes easier to define the anomaly. Associated defects such as VSD, ASD, and TOF can occur in 40% of cases of PA sling and should be looked for on echocardiography.

PART 12: UNIVENTRICULAR HEART AND HETEROTAXY SYNDROME INTRODUCTION Univentricular heart means a cardiac malformation in which a biventricular repair is not feasible and hence these hearts will be subjected to the “surgical univentricular pathway,” where the systemic venous return will be

directed to the pulmonary circulation either partially (bidirectional Glenn shunt) or totally (modified Fontan surgery). As per the unified reporting system of the Society of Thoracic Surgeons-Congenital Heart Surgery Database Committee, this includes the following.


Hearts unsuitable for biventricular correction are: • Univentricular AV connections • Tricuspid atresia • Mitral atresia and HLHS • Pulmonary atresia with intact ventricular septum • Heterotaxy syndromes • Cardiac malpositions • DORV with nonroutable VSD.

UNIVENTRICULAR ATRIOVENTRICULAR CONNECTIONS319-324 The unifying feature of hearts previously described as single, common, or univentricular is that the AV connection is completely or predominantly to a single ventricular chamber. Two basic situations may be present in univentricular physiology: • Both AV valves are committed to one ventricular chamber. • There may be only one AV valve permitting the access of only one atrium to the dominant ventricle (with the second ventricle being rudimentary). The literature has varying names for these hearts, namely cor triloculare biatriaum, cor biloculare, single ventricle, common ventricle, and univentricular heart. This group is subclassified into three groups based on the AV valve connections: • Double inlet ventricle (Fig. 72.202): Common form of single ventricle where there are two patent AV valves.

Fig. 72.202: Two-dimensional echocardiography. Apical fourchamber view showing the two inlets into a ventricle with left ventricular morphology in a case of double inlet left ventricle (DILV). (LA: Left atrium; LV: Left ventricle; RA: Right atrium).

•

•

1697

Single inlet ventricle: One of the AV valves is atretic and not patent. In this entity, either the left or the right AV valve is atretic and it is better to use the term left AV valve atresia or right AV valve atresia rather than tricuspid and mitral atresia (Fig. 72.203). Common inlet ventricle: In this case, the AV connection is through a common AV valve; this condition is commonly seen in heterotaxy syndromes (Figs 72.204A and B). The AV valve has free-floating leaflets and is classified as Rastelli type C AVSD.

Double Inlet Ventricle The classic form of single or common ventricle described as double inlet ventricle has been classified by Van Praagh into four types: • Double inlet LV • Double inlet RV • Double inlet ventricle of mixed morphology • Double inlet ventricle of indeterminate or undifferentiated morphology. The echocardiographic recognition of a double inlet ventricular with left or right morphology is based on two well-defined morphological principles. The first morphological principle states that left ventricular myocardium typically has a relatively smooth appearance with numerous fine oblique trabeculations, whereas RV myocardium has an irregular surface with relatively coarse straight trabeculations. The second principle states

Fig. 72.203: Two-dimensional echocardiography. Apical fourchamber view showing in a case of tricuspid atresia with hypoplastic right ventricle (RV), a large atrial septal defect (arrow) and a small muscular ventricular septal defect (VSD; star). (LA: Left atrium; LV: Left ventricle; RV: Right ventricle; RA: Right atrium).

1698


A

B

Figs 72.204A and B: Two-dimensional echocardiography. (A) Apical four-chamber view showing complete atrioventricular septal defect (AVSD) with a non–apex-forming small left ventricular (LV) cavity not suitable for biventricular pathway; (B) Shows a common AVSD (unbalanced type) with hypoplastic right ventricle (RV) on a single ventricular pathway. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

that the ventricular chamber that has an infundibulum giving rise to a great artery whether it represents the main ventricle or the hypoplastic outflow chamber represents the morphological RV. As a corollary, the ventricular chamber having a direct arterial connection without an intervening infundibulum represents a morphological LV. A good echocardiographic view of the foramen (bulboventricular foramen) separating the main ventricle into which both the AV valves connect with the outlet chamber should be obtained by using subcostal and parasternal windows. The differentiation of ventricular morphology as smooth surface versus irregular surface is also best made on these views. A careful look at either side of the bulboventricular foramen, (one side of which is main ventricle and other side is the rudimentary chamber) will show which of the sides has rough trabeculations and which side has a relatively smooth surface and this will define the main chamber and the rudimentary chamber as either the morphological right or the morphological left. Identifying on echo the infundibular chamber, which always goes with morphological RV, is important. A patent infundibulum always gives off a great artery and echocardiographic identification of an infundibulum is done by noting the separation from the AV valves, namely the AV valve–semilunar valve fibrous discontinuity. So a hypoplastic subarterial outlet chamber noted on echocardiography is indicative of morphological RV. If the rudimentary chamber is a blind chamber located inferiorly

and not giving off any great arteries, it is morphologically the LV. To restate the above echocardiographic principles for differentiation between the morphological right and LV again, if there is a univentricular heart with a rudimentary chamber located posteroinferiorly, which does not give off a great artery, and remains a blind pouch, then it is the left ventricular rudimentary chamber and so the main ventricle gets described as double inlet ventricle of RV morphology. Van Praagh describes such a morphological double inlet ventricle of RV morphology as a “hip pocket rudimentary left ventricular chamber,” to indicate that it is always posteriorly located. To summarize, double inlet ventricle is classified as double inlet ventricle of left ventricular morphology (accounts for 80% of double inlet ventricles) if the rudimentary outflow chamber is located anteriorly and gives off a great artery, and the rudimentary chamber has relatively coarser trabeculations on its surface near bulboventricular foramen. In double inlet ventricles of RV morphology (accounts for < 10% of double inlet ventricles), the rudimentary chamber is a blind posteroinferior “hip pocket pouch”; it does not give off any great artery and the main ventricle will have coarser walls than the rudimentary ventricle. The other two varieties of double inlet ventricle described by Van Praagh namely double inlet ventricle of mixed morphology and indeterminate morphology (account for < 10% of cases and are very rare) have echocardiographically no rudimentary chamber and both great arteries arise from the same main ventricular cavity.


1699

Double Inlet Left Ventricle

Assessment of the Systemic Veins

This is the commonest type of double inlet ventricle accounting for almost 80% of the double inlet ventricles. This group is subdivided into three subgroups based on the great artery relationship: • Left and anterior Aorta (L-malposed aorta): In 55% of double inlet left ventricle (DILV), the main LV gives off the PA , there is pulmonary valve–AV valve fibrous continuity, AV discordance, the rudimentary chamber is located on the left and anterior side of the morphological main LV, and the anterior rudimentary RV infundibular chamber gives off the aorta and the aorta is left and anterior to the PA . • Right and anterior Aorta (D-malposed aorta): In 30% of DILV, the main LV gives off the PA, there is pulmonary valve–AV valve fibrous continuity, the anterior rudimentary RV infundibular chamber gives off the aorta, and the aorta is right and anterior to the PA. • Normally related great arteries (Holmes Heart): In 15% of DILV, the main ventricular chamber gives off the aorta, there is aortic–AV valve fibrous continuity, the rudimentary anterior infundibular chamber gives off the PA, the PA is located left and anterior to the aorta, and the aorta–PA relation resembles that of a normal heart. Apical view shows double inlet ventricle and PSAX view shows normally related aorta–PA relationship; there is narrowing of the subpulmonary infundibulum causing subvalvular pulmonary stenosis. Rare variations from this schema include double outlet from the rudimentary chamber, atresia of one semilunar valve often the pulmonary valve, and truncus arteriosus.

In every patient with univentricular AV connection, since the path of palliation is univentricular, it is mandatory to be precise about the systemic and pulmonary venous anatomy before planning surgery. Systemic venous anomaly commonly present is bilateral SVC. With left isomerism, interrupted IVC should be looked for (seen in 85% of patients).

Double Inlet Right Ventricle The main RV gives off both great arteries, the semilunar valves of both aorta and PA are not in fibrous continuity to the AV valves, and a well-discerned rudimentary hip pocket (chamber) located posteriorly is of left ventricular morphology. Depending on the location of the posterior rudimentary LV, the segmental approach will vary as D-loop (when the rudimentary chamber is posterior and to the left), and L-loop (when the rudimentary chamber is posterior and to the right of the main RV). Since the longterm outcome after Fontan surgery for single ventricles of RV morphology is suboptimal compared to the single LVs, echocardiographic identification of the precise ventricular morphology as right and left is not just of academic interest but has prognostic significance.

Assessment of the Pulmonary Veins Anomalies of pulmonary venous return are also common in single ventricle patients, especially in the setting of heterotaxy syndromes. In single ventricular physiology with reduced pulmonary flows, the anomalous pulmonary venous drainage and associated obstruction of pulmonary veins may not show up clearly since the pulmonary venous flow will be of low velocity. Unidentified anomalous pulmonary venous drainage into the azygos vein may inadvertently be ligated/clipped as a part of Glenn shunt with serious implications. The echocardiographer should make serious attempts to trace all the pulmonary veins meticulously and ensure that no individual pulmonary vein drains anomalously into a chamber other than the atria and there is no obstruction in the pulmonary venous pathway.

Assessment of the Atrioventricular Valves It is imperative to assess the function of the AV valves precisely, since the AV valve function has an important bearing on the univentricular repair. Stenosis of the AV valves is common and may manifest with minimal gradients. Morphological features of these valves may be supramitral ring, hypoplastic AV valve, double orifice AV valve, parachute mitral valve or dysplastic AV valve. These have major effects on the univentricular pathway. Significant regurgitation of the AV valves too poses problems in univentricular surgical approach by increasing the atrial pressures and thereby impeding pulmonary venous return. Such valves may need annuloplasty and repair to minimize the degree of AV valve insufficiency. In patients with volume-overloaded heart, with increased pulmonary blood flow, the ventricular dilatation and associated AV valve annular dilatation results in regurgitation. Once the volume overload is arrested by surgical intervention like PA banding, ventricular volume reduces immediately and the AV valve regurgitation of such patients will reduce in severity.

1700


Bulboventricular Foramen The bulboventricular foramen is the orifice through which the main ventricular chamber feeds blood to the rudimentary outflow chamber. If the chamber supports the pulmonary flows like in Holmes heart, then restriction of the bulboventricular foramen results in restricted pulmonary blood flow. If the rudimentary outflow chamber supports the aortic circulation, restriction of bulboventricular foramen results in subaortic obstruction. To calculate the area of bulboventricular foramen, measure the maximum diameter of the bulboventricular foramen in two orthogonal planes. If the dimensions are “a” and “b,” then the area of the bulboventricular foramen is calculated assuming it to be an ellipse using the formula: Area = a + b/4 When the area of the bulboventricular foramen is > 2.0 cm2/m2, the foramen is considered nonrestrictive. In patients with area < 2.0 cm2/m2, during the initial palliation, the restrictive bulboventricular foramen may need to be addressed using one of the surgical strategies like Damus–Kaye–Stansel procedure (end-to-side anastomosis of the main PA to the ascending aorta) or enlargement of the bulboventricular foramen. In patients in whom the bulboventricular foramen is anatomically smaller though nonrestrictive by Doppler recordings, a close echocardiographic watch is justified. The progression of the hemodynamic narrowing of the bulboventricular foramen is explained as follows: initially with acute volume unloading of the ventricle after PA banding, there is an acute reduction of the ventricular volumes and reduction of the bulboventricular foramen area. Over long-term follow-up, there is progressive ventricular hypertrophy, which too results in further restriction of bulboventricular foramen size. In neonates who are too young and small to tolerate an enlargement of bulboventricular foramen or Damus–Kaye–Stansel procedure, alternative approaches followed include palliative arterial switch operation to shift the restrictive rudimentary outflow chamber from subaortic location to subpulmonary location. Alternative method is the measurement of the VSD size and comparing it with the aortic annulus size. If the 2D measurement of the VSD is less than aorta, it requires enlargement.

Single Inlet Ventricle This subgroup needs to be echocardiographically differentiated from morphological tricuspid atresia

and mitral atresia with hypoplastic right or left heart. Morphological definition for a single ventricle with one AV valve atresia is that the atretic or imperforate plate of the valve annulus overrides the ventricular septum and is predominantly (>50%) committed to the main ventricle. This means there is malalignment of the atrial and ventricular septa produced by AV valve annular override. Echocardiographic recognition of this feature will be done by demonstrating malalignment of the atrial and ventricular septum in a four-chamber, subcostal coronal and long-axis view with anterior tilt. In tricuspid atresia and mitral atresia, there will be alignment of the interatrial and ventricular septum and the atretic plate of the AV valve will be related to the hypoplastic RV or hypoplastic LV and will not override the ventricular septum.

TRICUSPID ATRESIA Tricuspid atresia is defined as complete agenesis of the tricuspid valve with no direct communication between the RA and RV. Morphologically, this entity is classified as in Table 72.17. Echocardiographic differentiation between tricuspid atresia and single ventricle with right AV valve atresia has already been highlighted in the previous discussion. We will now discuss the important echocardiographic features of this entity.

Tricuspid Atresia Type I Tricuspid atresia is associated with normally related great arteries in almost 75% of the cases. Rare instances are absence of interventricular communications and these patients have pulmonary atresia and do not have an echocardiographically demonstrable RV at all (Type Ia). However, in many instances, the VSD is restrictive and this restrictive VSD is the site of significant subpulmonary stenosis (Type Ib). Type Ia and Ib may require BT shunt prior to the planned Glenn shunt depending upon the systemic saturations. In patients with normally related great arteries, a large VSD (Type Ic) is often associated with unrestricted pulmonary blood flow and these patients present early with cyanosis and congestive heart failure and need PA banding. Echocardiographic evaluation of tricuspid atresia for a presurgical evaluation is mostly similar to the issues discussed under double inlet ventricles.


1701

Table 72.17: Classification of Tricuspid Atresia

Type 1: Normally related great arteries (75% of cases) Type 1a with pulmonary atresia Type 1b with pulmonary hypoplasia, small VSD Type 1c with no pulmonary hypoplasia, large VSD Type 2: d-Transposition of great arteries (25% of cases) Type 2a with pulmonary atresia Type 2b with pulmonary or subpulmonary stenosis Type 2c with no pulmonary hypoplasia and large VSD Type 3: l-Malposition of great arteries (very rare) Type 3a, pulmonary or subpulmonary stenosis Type 3b, subaortic stenosis (VSD: Ventricular septal defect)

Tricuspid Atresia Type II In patients with tricuspid atresia and d-transposition of great arteries, the size of VSD decides on the development of subaortic stenosis and hence it needs assessment similar to the bulboventricular foramen of univentricular heart. Another echocardiographically significant lesion frequently coexisting with tricuspid atresia and transposition of great vessels is aortic arch anomalies including arch and isthmic hypoplasia. In some patients with tricuspid atresia with transposition of great vessels, there will be left juxtaposition of atrial appendages. This condition is recognized echocardiographically by noting absence of right atrial appendage normally demonstrated in subcostal bicaval view as an anterior projection from the RA immediately below the SVC–right atrial junction. In juxtaposition of atrial appendages, the appendage is missing in this location, but instead noted on left side of the great arteries.

MITRAL ATRESIA AND HYPOPLASTIC LEFT HEART SYNDROME (FIGS 72.204 AND 72.205) This condition is included in this discussion, since it also needs a univentricular type of repair. This syndrome embraces a continuum of congenital cardiac anomalies characterized by underdevelopment of the aorta, aortic valve, LV, mitral valve, and LA to a varying extent. Echocardiographic diagnosis of this entity will help in quick recognition of the duct dependency of the systemic circulation. The aortic arch color Doppler flow imaging will show typical flow reversal in arch of aorta from the level of

the duct, since the arch and ascending aorta get retrograde flows from the patent ductus. Prompt recognition of such flow reversal in aortic arch and duct dependence of systemic circulation will help in early institution of prostaglandin E1 therapy and transfer to an advanced cardiac surgical center. Another important echocardiographic decision-making issue is identification of adequacy of interatrial septal communication. Since ASD is the only outlet for pulmonary venous blood, inadequate atrial communication will need urgent enlargement either in cardiac catheterization suites or operation rooms. In some cases of mitral atresia, decompression of the LA through a small unroofing of the coronary sinus may be present.

Hypoplastic Left Heart Syndrome Initial echocardiographic assessment of the HLHS (before Stage 1 palliation, i.e. before Norwood procedure): The goal of the assessment is to provide an accurate diagnosis and complete hemodynamic information keeping in mind that the parameters for future univentricular pathway need to be looked at. Objectives of echocardiography are to assess: • Anatomical and physiological components of HLHS: LA, mitral valve, LV, LVOT, aortic valve, ascending aorta, aortic arch, and isthmus • Adequacy of interatrial communication • Anatomy of the ductus and determine its adequacy and physiology • Anatomy of the RV, RV outflow, tricuspid valve, and pulmonary valve • RV function, AV regurgitation if any.

1702


A

B

C

D

Figs 72.205A to D: Two-dimensional echocardiography with color flow mapping in a case of left ventricular (LV) hypoplasia. (A) Fourchamber view with color flow mapping showing a restrictive interatrial communication; (B and C) Apical four-chamber view with color flow compare showing a small LV cavity with thickened endocardium and flow acceleration across the mitral valve; (D) Suprasternal view showing a hypoplastic ascending aorta and transverse arch. (As Ao: Ascending aorta; Ds Ao: Descending aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; TA: Transverse arch).

Associated Systemic Venous Anomalies The evaluation is as for all CHD entities with sequential analysis. Certain characteristic features that may be looked at are enumerated below.

Subcostal View As the transducer is tilted toward the cardiac base, the coronary sinus, RA, and RV are visualized. A dilated coronary sinus should alert one for the presence of LSVC or anomalous pulmonary venous connection to the coronary sinus. The RA in typical scenario is dilated and hypertrophied from obligatory left-to-right shunting through the patent foramen ovale. The RV also is dilated

as compared to the small LV. From the subcostal views, a careful assessment of the adequacy of the interatrial communication is done. The other feature that needs to be looked at includes pulmonary venous connections, size and function of the ventricular chambers, and evaluation of the AV valves. Atrial septum: Frequently, there is a leftward deviation of the superior attachment of the atrial septum. The severity of the restriction at the atrial septal communication can be assessed by using color or spectral Doppler. The mean gradient is obtained over three cardiac cycles. Pulmonary veins: Anomalous pulmonary venous connection/drainage occur in 5 to 10% of the cases of HLHS. In cases of restricted interatrial septal communication,


a decompressing vein may be visualized from the LA draining to variable locations. These may be stenosed and, therefore, a full view of the course of the drainage of these venous channels is needed. This could be assisted by use of PW Doppler interrogation and color flow mapping. Anterior angulation demonstrates the dilated RV and RVOT. This needs to be carefully evaluated as this will be the sole outflow tract from the cardiac chamber in the near future. Associated pulmonary stenosis and pulmonary valve regurgitation represent a poor subset. The hypoplastic (tiny) ascending aorta may at times be better visualized in the subcostal views.

Apical Views Apical four-chamber view provides comparison of the relative right and left sides of the heart. The RV is generally large and hypertrophied, and the LV is small, musclebound, and nonapex forming. The endocardial surface of the LV is often echogenic because of endocardial fibroelastosis. This in itself is a very important prognostic marker (particularly in borderline situations where one is contemplating a two-ventricle repair). The morphology of the mitral and the tricuspid valve can also be evaluated in this view. The annulus of the mitral valve is typically hypoplastic, severely stenosed, or may be atretic. This may be evaluated using color flow mapping and Doppler assessment. In case of stenosis of the mitral valve without mitral regurgitation, one should be alerted to the likelihood of ventriculocoronary sinusoids. Tricuspid valve morphology and function needs to be assessed also. It is important to identify and quantify the tricuspid regurgitation, an important prognostic feature. RV function is also assessed in this view. Anterior tilt will show the aortic valve, ascending aorta, and pulmonary trunk. Doppler assessment of the aortic valve and color flow mapping will show the patency of the aortic valve. The pulmonary valve should also be similarly investigated.

Parasternal Views Parasternal views are important to assess ventricular function and size and function of the AV valves. The dilated RV is seen anteriorly and the small LV, posteriorly. The ventricular septum is usually intact. The aortic valve is either stenosed or atretic and LVOT may have subaortic obstruction, which can also be seen in this view. The morphology of the mitral valve should be studied and the dimensions of the mitral and aortic valve annulus

1703

measured in this view. Angling the transducer inferiorly allows assessment of the tricuspid valve and tricuspid regurgitation. Angling the transducer anteriorly shows the pulmonary valve and the RVOT. This needs to be seen for the presence of any obstruction. Pulmonary regurgitation needs to be evaluated. Short-axis sweeps allow assessment of the mitral valve and subvalvular pathology. It also allows determining the morphology of the aortic valve and the coronaries. The RCA is usually prominent because of its supply to the dominant RV. In the presence of LV to coronary fistulous connections, the LCA may become prominent. High PSAX view allows visualization of PA branches and the arterial ductus. This view will also show the length of the decompressing venous channel by tilting the transducer posteriorly. Slight counterclockwise rotation may show the large ductus; this may be larger than the arch and the pulmonary arteries.

Suprasternal Notch View This provides full assessment of the aortic arch. The sidedness of the arch should be determined; the aortic arch has a more acute curve than normal in these patients. The sizes of the ascending aorta, transverse arch, and isthmus should be measured and the posterior shelf of coarctation of the aorta should be evaluated. Doppler sampling of the distal segment of the aortic arch reveals retrograde flow in systole into the transverse arch and antegrade flow in diastole into the ductus arteriosus and pulmonary vascular bed.

Echocardiographic Assessment After the Stage 1 Palliation The Norwood procedure consists of surgical reconstruction and augmentation of the ascending aorta and aortic arch with aortopulmonary amalgamation, an atrial septectomy, and systemic to pulmonary shunt, which can be either a Blalock–Taussig shunt or a RV to PA conduit (Sano’s modification and PA banding). Interatrial septal assessment is important as restriction may occur mostly due to inadequate resection, an important cause of cyanosis. The right BT shunt may be visualized from the suprasternal short- or long-axis views with angulation of the transducer toward the right side. Postoperative complications of the shunt including pulmonary over circulation, shunt stenosis, and hence PA distortion may occur and need evaluation. Sano’s shunt can be best visualized by subcostal and modified apical views.

1704


Modified apical view is obtained by moving the transducer anteriorly. Sliding the transducer up toward midsternum will permit viewing the distal aspect of the conduit and PA branches. Narrowing of the shunt at any point along its course or at its insertion into the PA should be identified. Color flow mapping and Doppler interrogation of the conduit and proximal branch pulmonary arteries should demonstrate a typical to and fro pattern of flow. Evaluation of RV function and tricuspid regurgitation should be performed from multiple imaging planes. Echocardiographic evaluation of the neoaorta and arch is also important with the distal aortic arch deserving special attention. The ongoing evaluation after the first stage Norwood is same as for Glenn and Fontan pathway.

characterized by bilateral right atrial appendages and left isomerism with both appendages of left morphology. Although there are several cardiac anomalies that are common to both forms, certain unique features help to differentiate the two forms. Right isomerism is associated with absence of spleen in majority of cases and hence it is also referred to as “asplenia syndrome.”328 Left isomerism is characterized by presence of multiple, albeit abnormal, spleens and is hence called “polysplenia syndrome.” Several extracardiac anomalies other than those that involve the spleen are associated with these syndromes. Tables 72.18 and 72.19 compare cardiac and extracardiac anomalies found in these two syndromes.

Initial Echocardiogram (Table 72.20) HETEROTAXY SYNDROME Introduction The term visceral heterotaxy originates from the Greek word “heteros – other than” and “taxis – arrangement.” It basically refers to any arrangement of body organs in patterns other than the usual (situs solitus) or its mirror image variant (situs inversus).319–325 Very often, these conditions are associated with an abnormal number and arrangement of the spleen, and hence the term “splenic syndromes” has often been given to these conditions. Cardiac malformations associated with these syndromes are often complex with abnormalities at various levels of the cardiac axis (visceroatrial situs, ventricular loop, and ventriculoarterial connections). The characteristic cardiac abnormality found in the heart is referred to as “isomerism of atrial appendages,” whereby both the atrial appendages have either right or left morphology.326,327 Current echocardiographic techniques allow a complete structural evaluation of the entire cardiac anomalies in these patients, so that cardiac catheterization is required only for hemodynamic evaluation prior to consideration of single ventricle palliation in selected cases. In this chapter, we discuss the steps involved in the systematic evaluation of the heart and great vessels in patients with visceral heterotaxy.

Anatomical Background: Characterization of Two Distinct Heterotaxy Syndromes Two distinct patterns emerge when we consider cardiac abnormalities in these complex syndromes—right isomerism and left isomerism. Right isomerism is

In view of the complex nature of associated cardiac abnormalities, most of the patients will come to clinical attention in the neonatal period or early infancy itself. The basic aim of the initial echocardiogram is to assess the entire spectrum of the cardiac anatomy with special emphasis on evaluation of pulmonary blood flow. A segmental approach starting from the determination of the visceral and atrial situs, and then proceeding to each segment in the heart and great arteries is recommended.329 In most cases, initial palliation is possible on the basis of echocardiographic evaluation alone without resorting to cardiac catheterization. The steps involved in the initial echocardiographic evaluation are as follows:

Determination of Abdominal Situs and Cardiac Position This is achieved using the subcostal short-axis view. In situs solitus, the liver will be found to occupy the right side with the stomach on the left side of the spine. The aorta will occupy the left side of the spine and IVC on the right side. In situs inversus, this arrangement is reversed with aorta occupying the right anterior aspect of the spine. The position of the heart can be determined by cranial tilt of the transducer and determining which way the apex of the heart points (left—levocardia; right—dextrocardia; middle—mesocardia). The position of the heart (levo or dextrocardia) does not help in differentiation of right and left isomerism. In patients with visceral heterotaxy, the position of the liver can be to the right, to the left, or transverse. The stomach can be on either side or midline. These


1705

Table 72.18: Cardiac and Extracardiac Anomalies in Isomerism Syndromes

Right Isomerism

Left Isomerism

Dextrocardia

40%

40%

Right pulmonary isomerism

70%

10%

Left pulmonary isomerism

Rare

60%

Bilateral superior vena cava (SVC)

50%

40%

Absent inferior vena cava (IVC)

Rare

70%

Total anomalous pulmonary venous connection (TAPVC)

70%

Rare

Partial anomalous pulmonary venous connection

Rare

40%

Atrial septal defect (ASD)/common atrium

90%

80%

Atrioventricular (AV) septal defect

85%

40%

Single ventricle

50%

10%

Transposed great arteries

80%

30%

PS/pulmonary atresia

80%

30%

LVOTO

Rare

40

Extracardiac anomalies

CNS, gastrointestinal, skeletal and genitourinary

Biliary atresia Intestinal malrotation Agenesis of gall bladder

Source: Gutgesell HP. Cardiac Malposition and Heterotaxy. In: Garson Jr, Bricker JT, Fischer DJ, Neish SR, editors. The Science and Practice of Pediatric Cardiology. Baltimore, MD: Williams & Wilkins; 1998:1539–61.

relationships do not help differentiate between right and left isomerism. However, the characteristic arrangement of the aorta and IVC in relation to the spine will give a clue to the diagnosis and help to differentiate between the two types. In right isomerism, the aorta and IVC will be found to occupy the same side of the spine (right or left), with the IVC occupying a position more anterior to the spine than the aorta. In left isomerism, the IVC is often interrupted with the abdominal portion of the IVC continuing as azygos or hemiazygos veins.330 This venous channel is distinguished by location on the same side of the spine as the aorta, but in a posterior position. All these relations are best demonstrated using the subcostal sagittal scan and short-axis scan.

Venoatrial Connections—Systemic Veins Abnormalities of the systemic veins are very common in both syndromes. Knowledge of the systemic venous anatomy is very important since a vast majority of these patients eventually require palliation via the univentricular pathway. The patterns and frequencies of these anomalies are summarized in Table 72.18. Superior vena cava: Right isomerism is characterized by presence of bilateral SVC, which typically drains to the roof

of atrium on both sides. The frequency of bilateral SVC is lower in left isomerism. SVC drainage to the atrium can be best demonstrated using the subcostal sagittal coronal or four-chamber and suprasternal views. LSVC drainage is best noted by suprasternal long-axis and short-axis views with leftward tilt of the transducer.332 In these views, the LSVC is seen descending in front and to left of the aortic arch and pulmonary hilum toward the atrioventricular groove. In the suprasternal short-axis views, the presence of bilateral SVC can be demonstrated and the presence and size of the bridging vein can be assessed. In patients with right isomerism, LSVC will be seen draining to the roof of the atrium between the left upper pulmonary vein and left-sided atrial appendage. In patients with left isomerism, LSVC may drain to the coronary sinus. Color flow mapping should be used to determine the exact point of insertion of the SVC into the atrium. PW Doppler is useful in differentiating LSVC from similar appearing structures (left levocardinal vein) by demonstrating flow toward the heart. In cases with bilateral SVC, the actual sizes of both SVC and the presence and size of the bridging vein should be noted. Inferior vena cava: Most patients with right isomerism have no abnormalities of the IVC drainage with the IVC receiving the hepatic veins and draining to the RA. However, a vast

1706


majority of patients with left isomerism have abnormal IVC drainage, with interruption in IVC being the most common anomaly. The subcostal short-axis view shows the azygos vein as a large vessel on posterior and rightward Table 72.19: Venoatrial Connections in Isomerism Syndromes

Right Isomerism

Left Isomerism

Superior vena cava (SVC) Unilateral to right

29%

22%

Unilateral to left

20%

16%

Bilateral to roof

51%

38%

Bilateral, one via coronary sinus

—

24%

To right-sided atrium

48%

12%

To left-sided atrium

52%

12%

Interrupted on right

—

34%

Interrupted on left

—

42%

Inferior vena cava (IVC)

Hepatic veins Confluence to IVC

76%

14%

Confluence to atrium

—

43%

Unilateral to atrium

6%

8%

Bilateral to atrium

18%

35%

To right-sided atrium

19%

26%

To left-sided atrium

19%

14%

Bilaterally to atriums

—

60%

Centrally via confluence

3%

—

To extracardiac site

59%

—

Pulmonary veins

Source: Uemura et al. Annals of Thoracic Surgery. 1995;60:561–9.

aspect of the spine. In the subcostal sagittal view, this large vessel can be traced to the posterior aspect of the aorta draining to the posterior aspect of the right SVC. In hemiazygos continuation of the IVC, the abdominal portion of the right IVC is absent. Blood from the lower body returns to the heart by way of a left-sided continuation of a venous channel (“hemiazygos continuation”), which drains to LSVC or coronary sinus. The subcostal short-axis view of the abdomen shows a large venous channel on the left posterior aspect of the spine. Using the subcostal sagittal view with cranial angulation and suprasternal view, the drainage of this vessel to the heart can be imaged. Hepatic veins: Evaluation of the hepatic vein drainage is vital in evaluation of patients with interrupted IVC, especially before consideration of the bidirectional cavopulmonary shunt (BCPS; Kawashima Operation). Anomalies in the hepatic venous drainage have been implicated in the genesis of pulmonary arteriovenous fistulae after BCPS in these patients, leading to systemic desaturation.7 This will necessitate re-routing the hepatic veins to the pulmonary circulation. In patients with left isomerism, different patterns of hepatic venous drainage have been demonstrated (Table 72.19). The veins can drain unilaterally or bilaterally to the atrium or may form a confluence and then drain to the atrium. The presence of bilateral drainage to both atria often makes a subsequent Fontan conversion more difficult technically. In patients with right isomerism, hepatic venous drainage is normal with all veins forming a confluence and draining into the suprahepatic portion of the IVC. The abnormalities of the hepatic venous drainage are best demonstrated using the subcostal short-axis view with cranial tilt and subcostal sagittal view.333

Table 72.20: The Echocardiographic Checklist for the Univentricular Pathway Patient

Look at the electrocardiography (ECG) for any rhythm abnormality Evaluation of the pulmonary artery (PA) pressures: these may be done from shunt lesions such as patent ductus arteriosus (PDA) or pulmonary outflow gradients Ventricular dysfunction Systemic atrioventricular (AV) valve regurgitation Aorta and subaortic obstruction if any Presence of interatrial communication may be essential in certain circumstances Pulmonary venous drainage Systemic venous drainage and to look at systemic veins Pulmonary artery anatomy: (a) size of the pulmonary arteries, (b) distortion of the pulmonary arteries


Abnormalities of coronary sinus: A characteristic feature of right isomerism is the absence of the coronary sinus with the cardiac veins draining directly to the atrium. The absence of the coronary sinus can be demonstrated in the apical four-chamber view and subcostal sagittal view. The LSVC, if present, will be directly draining to the roof of the atrium between the left upper pulmonary vein and left atrial appendage. Drainage of LSVC to coronary sinus can be seen in patients with left isomerism.

Venoatrial Connections: Pulmonary Veins Abnormal pulmonary venous drainage is more common in patients with right isomerism. A majority (>80%) of these cases have TAPVCs to right-sided atrium or systemic veins. TAPVC in the setting of right isomerism can occur to supracardiac, intracardiac, or infracardiac locations. When pulmonary veins enter the atrium directly (without confluence or common pulmonary vein), they tend to drain to the smooth intercaval portion of the atria. Forty percent of patients with left isomerism have PAPVC with right veins entering the right-sided atrium and left veins to left-sided atrium. This may result from leftward malalignment of atrial septum. Obstruction to pulmonary venous flow is also more common in the setting of right isomerism. This is particularly important to identify before consideration of placement of a systemic–PA shunt to increase pulmonary blood flow. Failure to identify an obstructed TAPVC will lead to development of severe, often fatal, pulmonary edema after placement of the shunt. Pulmonary venous drainage can be imaged from the subcostal coronal, apical four-chamber, PSAX, and suprasternal views. The presence of a confluence, size of individual veins, drainage of all veins to confluence, presence of additional directly draining veins, and adequacy of communication of the confluence to atrium/ systemic veins should be identified. Color flow mapping and PW Doppler will help identify obstruction in the pulmonary venous drainage. Obstruction to pulmonary venous flow will produce characteristic high velocity (>2 m/s), continuous flow signals on PW Doppler. Obstruction to pulmonary venous drainage can occur at the site of insertion of the veins to SVC, at the junction of vertical vein to brachiocephalic vein, at the level of infracardiac drainage of the veins, or by external compression when the vertical vein runs a retrobronchial course (specific to right isomerism).334,335

1707

Atria and Appendages In some patients with heterotaxy, discordance between atrial and abdominal situs has been described. Drainage of systemic veins, presence of tendinous insertion of the Eustachian valve, and limbus of fossa ovalis on septal surface characterizes RA, while the flap valve of the fossa ovalis on the other side is generally an indicator of LA. However, in patients with heterotaxy, the venoatrial connections, vestibular morphology, and atrial septal structure are all variable. Identification of the atrial situs is often best done by evaluating the morphology of the atrial appendages. The characteristic features of the right atrial appendage are larger size, triangular appearance, broad base, and presence of pectinate muscle extending till the crux of the heart. The left atrial appendage, in contrast, is smaller, has a tubular appearance with narrow base, and has pectinate muscle at the vestibule only. However, pectinate muscles cannot be profiled on echocardiography. Using these features, the atrial situs can be determined in the vast majority of patients with heterotaxy. The term “situs ambiguous” should be reserved to the very few patients where the atrial situs cannot be determined even after evaluating all the above mentioned features. The atrial appendages are best visualized using TEE. Using transthoracic echocardiography, the right atrial appendage is well visualized in the PLAX view through the RV inflow tract and subcostal sagittal view. The left atrial appendage is well seen in PSAX and subcostal fourchamber views.336,337

Atrial Septum Common atrium with both atria having right morphology is often associated with right isomerism. In patients with left isomerism, 50% of cases have common atrium. The morphology of the atrial septum does not help in differentiating between right and left isomerism. The ASD is best imaged using the subcostal coronal and sagittal views. The adequacy of the size of the interatrial communication is important before consideration of a single ventricle repair.

Atrioventricular Junction The atrioventricular connections in patients with isomerism can be biventricular or univentricular. The ventricular topology can be either D-loop or L-loop,

1708


with D-Loop patterns dominating. Left isomerism has a higher prevalence of biventricular atrioventricular connection compared with right isomerism (74% vs 46%). Univentricular connections are much more common in right isomerism. Irrespective of the nature of atrioventricular connection, most patients with isomerism (93% in right and 67% in left) have a common atrioventricular valve. It is very important to assess the degree of regurgitation of the common valve, its mechanisms, and possibility of repair before consideration of single ventricle palliation, since it is a major risk factor for surgery. The anatomy of the valve is best assessed by subcostal coronal view with anteroposterior sweeps, subcostal en face view, and apical four-chamber views.338

Ventricles and Ventricular Septum A univentricular heart is more common in patients with right isomerism than left. Within the category of isomeric hearts with single ventricle, morphological RV type of single ventricle is more common. In patients with univentricular heart and double inlet connection via a common atrioventricular valve, the position of the ventricular septum relative to the common valve will help to identify the ventricular morphology. If the septum is found anterior to the valve, the ventricular morphology will be that of LV; if it is posterior, it suggests RV. Failure to identify a ventricular septum indicates single ventricle of indeterminate morphology. In cases of RV type of single ventricle, the rudimentary LV cavity is located posterior or on the diaphragmatic surface of the heart with no arterial outlets. If the single ventricle is of the LV type, a rudimentary RV/outflow chamber will be present with at least one of the great arteries typically arising from that chamber. In patients with biventricular connections and common AV valve (more common in left isomerism), the ventricular morphology can be identified by the nature of trabeculations, papillary muscles, and site of septal attachment of inferior bridging leaflets. Associated anomalies of the ventricle include presence of noncompaction of the ventricular myocardium. A thorough evaluation of the ventricular systolic and diastolic function should be undertaken in the initial evaluation as well as in evaluation prior to single ventricle repair. End-systolic and end-diastolic volumes and ejection fraction are calculated. The ventricular mass can be calculated by subtracting the endocardial volume from the epicardial volume and multiplying the resultant myocardial volume by 1.05 (specific gravity

of myocardium). The diastolic function of the ventricle can be assessed by Doppler evaluation of the AV valve and pulmonary veins. The application of newer imaging modalities like tissue Doppler imaging, harmonics, and strain rate imaging are yet to be standardized for use in these patients. In patients with biventricular connections (more common in left isomerism), an attempt should be made to assess for possibility of biventricular repair. Factors that decide this include characteristics of the AV valve (balanced vs. unbalanced, subvalvular apparatus straddling) and characteristics of the VSD (location, routability, presence of multiple VSDs, etc.). The relationship of the conducting system with respect to the VSD also is an important consideration in view of risk of heart block when biventricular repair is attempted. Evaluation of the ventricles and ventricular septum is done using a combination of subcostal long- and shortaxis views, four-chamber view with cranial angulation, and parasternal long- and short-axis views.

Ventriculoarterial Connections In patients with right isomerism, the common abnormalities of the ventriculoarterial connections are DORV with pulmonic stenosis/atresia and single outlet with no pulmonary outflow. Discordant ventriculoarterial connections may also be seen. The assessment of severity of pulmonary stenosis is very important. The outflow tracts can be imaged using subcostal coronal, four-chamber, and PSAX views. Doppler evaluation of the gradient across the pulmonary outflow (subvalvular and valve) will provide an estimate of PA pressures. However, in presence of pulmonary venous obstruction, Doppler estimation of the gradient may underestimate the severity of the obstruction of outflow. In such cases, attention should focus on morphology of the outflow tract. In left isomerism, concordant ventriculoarterial connections are more common and obstruction to pulmonary outflow is less common.

Branch Pulmonary Arteries and Sources of Pulmonary Blood Flow Evaluation of branch pulmonary arteries constitutes one of the most essential aspects of evaluation prior to any form of surgical repair. This is best done from the PSAX view, the ductal (high parasternal view), and suprasternal views. The presence of the confluence of pulmonary arteries is


first determined. The diameter of the branch PAs is then measured at the level of the hilum. Adequacy of the sizes of the branch PAs can be determined by calculating the z-scores. The presence of narrowing at any point along the PA (origin, site of previous shunt, etc.) is documented. It is important to discriminate between focal areas of stenosis (repairable) and more diffuse stenosis of the entire PA. The sources of pulmonary blood flow (antegrade, ductus, or aortopulmonary collateral) need to be determined. The presence of bilateral ductus supplying the right and left pulmonary arteries is common in right isomerism. This is best demonstrated by suprasternal views. The presence of MAPCAs can be evaluated in the suprasternal and subcostal long-axis views, this may not be possible to assess by echocardiography of the descending aorta. Large MAPCAs will cause flow reversal in the descending aorta. MAPCA can be identified by presence of continuous flow in the vessel, tortuous course, and direct termination to the lung (instead of PA).

Aortic Arch and Branches Obstruction to aortic outflow is more common in patients with left isomerism with common atrioventricular valve. From the four-chamber view with cranial angulation (fivechamber view) and PLAX view, the LVOT can be visualized and presence of any obstruction across the aortic valve is assessed. If there is obstruction, the gradients can be calculated. The morphology of the aortic valve is best assessed in the PSAX view. The evaluation of the arch is best done from the suprasternal views. Measurements of the aorta at levels of ascending aorta, transverse arch, isthmus, and descending aorta are taken in all patients. The presence of localized/diffuse constriction and gradients across the points of obstructions are also measured.

ACKNOWLEDGMENTS We are indebted to our colleagues for their cooperation. We wish to express our heartfelt thanks and gratitude to our secretary Ms Poonam Toppo for her secretarial help and Dr Kunal Bhagatwala for the correction of the proof of the chapter and helping with the movie clips.

REFERENCES Basics of Imaging and Sequential Segmental Analysis 1. Shrivastava S, Radhakrishnan R, Tomar M, editors. Echocardiography in Pediatric Heart Disease. 1st ed. Siddhart; 2009.

1709

2. Vermilion PR, Snider AR, Serwer AG, et al. Basic physical principles. In: Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby;1997:1–10. 3. Nishimura RA, Miller FA Jr, Callahan MJ, et al. Doppler echocardiography: theory, instrumentation, technique, and application. Mayo Clin Proc. 1985;60(5):321–43. 4. The normal echocardiographic examination. In: Snider AR, Serwer AG, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby; 1997:22–75. 5. Kimball TR, Meyer RA. In: Allen JD, Gutsesell HP, Clark EB, Driscoll DJ, editors. Echocardiography in Heart disease in Infant, Children, and Adolescents. 6th ed. Philadelphia: Lippincott, Williams, & Wilkins;2000:204–33. 6. American Academy of Pediatrics Committee on Drugs. Guidelines for monitoring and management of pediatrics patients during and after sedation for diagnostic and therapeutic procedures. Pediatrics. 1992;89:1110. 7. Lange LW, Sahn DJ, Allen HD, et al. Subxiphoid crosssectional echocardiography in infants and children with congenital heart disease. Circulation. 1979;59(3):513–24. 8. Weyman AE, et al. Noninvasive visualization of the left main coronary artery by cross sectional echocardiography. Circulation. 1976;54:169. 9. Van Praagh R. The segmental approach to diagnosis in congenital heart disease. In: Bergsma D, editor. Birth Defects: Original Article Series. The National Foundation— March of Dimes (Volume 8, No. 5). Baltimore, MD: Williams and Wilkins; 1972: 4–23. 10. Shinebourne EA, Macartney FJ, Anderson RH. Sequential chamber localization—logical approach to diagnosis in congenital heart disease. Br Heart J. 1976;38(4):327–40. 11. Anderson RH, Smith A, Wilkinson JL. Disharmony between atrioventricular connections and segmental combinations: unusual variants of “crisscross” hearts. J Am Coll Cardiol. 1987;10(6):1274–7. 12. Anderson RH, Brown NA, Uemura H. Clinical aspects of symmetry and isomerism. Ann Cardiac Surg. 95–103. 13. Anderson RH, Siew YH. Sequential segmental analysis— description and categorization for the millennium. Cardiol Young. 1997;7:98–116. Shunt Section 14. Child JS. Echo-Doppler and color-flow imaging in congenital heart disease. Cardiol Clin. 1990;8(2):289–313. 15. Dillon JC, Weyman AE, Feigenbaum H, Eggleton RC, Johnston K. Cross-sectional echocardiographic examination of the interatrial septum. Circulation. 1977;55(1): 115–20. 16. Nasser FN, Tajik AJ, Seward JB, et al. Diagnosis of sinus venosus atrial septal defect by two-dimensional echocardiography. Mayo Clin Proc. 1981;56(9):568–72. 17. Assessment of right to left shunt flow in atrial septal defect by transesophageal color and pulsed Doppler echo cardiography OK. J Am Soc Echocardiogr. 1994, 7(5):506–15. 18. Mehta AV, Goenka S, Chidambaram B, et al. Natural history of isolated ventricular septal defect in the first five years of life. Tenn Med 2000;93(4);136–8.

1710


19. Capelli H, Andrade JL, Somerville J. Classification of the site of ventricular septal defect by 2-dimensional echocardiography. Am J Cardiol. 1983;51(9):1474–80. 20. Ventricular septal defect. In: Tyanan M, Anderson RH, editors. Paediatric Cardiology. 2nd ed. Churchill Livingstone; 2002:983–1014. 21. Hagler DJ, Edwards WD, Seward JB, et al. Standardized nomenclature of the ventricular septum and ventricular septal defects, with applications for two-dimensional echocardiography. Mayo Clin Proc. 1985;60(11):741–52. 22. Bierman FZ, Fellows K, Williams RG. Prospective identification of ventricular septal defects in infancy using subxiphoid two-dimensional echocardiography. Circulation. 1980;62(4):807–17. 23. al-Marsafawy HM, Ho SY, Redington AN, et al. The relationship of the outlet septum to the aortic outflow tract in hearts with interruption of the aortic arch. J Thorac Cardiovasc Surg. 1995;109(6):1225–36. 24. Schmidt KG, Cassidy SC, Silverman NH, t al. Doubly committed subarterial ventricular septal defects: echocardiographic features and surgical implications. J Am Coll Cardiol. 1988;12(6):1538–46. 25. Ortiz E, Robinson PJ, Deanfield JE, et al. Localisation of ventricular septal defects by simultaneous display of superimposed colour Doppler and cross sectional echocardiographic images. Br Heart J. 1985;54(1):53–60. 26. Helmcke F, de Souza A, Nanda NC, et al. Two-dimensional and color Doppler assessment of ventricular septal defect of congenital origin. Am J Cardiol. 1989;63(15):1112–16. 27. Murphy DJ Jr, Ludomirsky A, Huhta JC. Continuous-wave Doppler in children with ventricular septal defect: noninvasive estimation of interventricular pressure gradient. Am J Cardiol. 1986;57(6):428–32. 28. Rudolph AM, Heymann MA, Spitznas U. Hemodynamic considerations in the development of narrowing of the aorta. Am J Cardiol. 1972;30(5):514–25. 29. Huhta JC, Cohen M, Gutgesell HP. Patency of the ductus arteriosus in normal neonates: Two dimensional echocardiography vs. Doppler assessment. J Am Coll Cardiol. 1984; 4:561–4. 30. Silverman NH. Patent ductus arteriosus. In: Pediatric Echocardiography. Baltimore, MD: Williams & Wilkins; 1993:167–77. 31. Liao PK, Su WJ, Hung JS. Doppler echocardiographic flow characteristics of isolated patent ductus arteriosus: better delineation by Doppler color flow mapping. J Am Coll Cardiol. 1988;12(5):1285–91. 32. Swensson RE, Valdes-Cruz LM, Sahn DJ, et al. Real-time Doppler color flow mapping for detection of patent ductus arteriosus. J Am Coll Cardiol. 1986;8(5):1105–12. 33. Abnormal vascular connections and structures. In: Snider AR, Serwer AG, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby; 1997:452–96. 34. Kutsche LM, Van Mierop LH. Anatomy and pathogenesis of aorticopulmonary septal defect. Am J Cardiol. 1987; 59(5):443–7.

35. Berry TE, Bharati S, Muster AJ, et al. Distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum, patent ductus arteriosus and hypoplasia of the aortic isthmus: a newly recognized syndrome. Am J Cardiol. 1982;49(1):108–16. 36. Boonstra PW, Talsma M, Ebels T. Interruption of the aortic arch, distal aortopulmonary window, arterial duct and aortic origin of the right pulmonary artery in a neonate: report of a case successfully repaired in a one-stage operation. Int J Cardiol. 1992;34(1):108–10. 37. Mori K, Ando M, Takao A, et al. Distal type of aortopulmonary window. Report of 4 cases. Br Heart J. 1978;40(6):681–9. 38. Richardson JV, Doty DB, Rossi NP, et al. The spectrum of anomalies of aortopulmonary septation. J Thorac Cardiovasc Surg. 1979;78(1):21–7. 39. Bertolini A, Dalmonte P, Bava GL, et al. Aortopulmonary septal defects. A review of the literature and report of ten cases. J Cardiovasc Surg (Torino). 1994;35(3):207–13. 40. Redington AN, Rigby ML, Ho SY, et al. Aortic atresia with aortopulmonary window and interruption of the aortic arch. Pediatr Cardiol. 1991;12(1):49–51. 41. Balaji S, Burch M, Sullivan ID. Accuracy of cross-sectional echocardiography in diagnosis of aortopulmonary window. Am J Cardiol. 1991;67(7):650–3. 42. Deverall PB, Lincoln JC, Aberdeen E, et al. Aortopulmonary window. J Thorac Cardiovasc Surg. 1969;57(4):479–86. 43. McMahon CJ, DiBardino DJ, Undar A, et al. Anomalous origin of left coronary artery from the right pulmonary artery in association with type III aortopulmonary window and interrupted aortic arch. Ann Thorac Surg. 2002;74 (3):919–21. 44. Shore DF, Ho SY, Anderson RH, et al. Aortopulmonary septal defect coexisting with ventricular septal defect and pulmonary atresia. Ann Thorac Surg. 1983;35(2):132–37. 45. Snider AR, Serwer AG, Ritter SB, editors. Defects in cardiac septation. In: Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby;1997:235–96. 46. Michael MB, Michael AH. Aortopulmonary window. In: Allen JD, Gutsesell HP, Clark EB, Driscoll DJ, editors. Heart disease in Infant, Children, and Adolescents. 6th ed. Philadelphia: Lippincott Williams, & Wilkins;2000:670–4. 47. Duca V, Sulliotti G, Maggio C, et al. Transposition of the great arteries and aortopulmonary window in the same patient: clinical report and follow-up. Pediatr Cardiol. 2002;23(4):474–5. 48. Geva T, Ott DA, Ludomirsky A, et al. Tricuspid atresia associated with aortopulmonary window: controlling pulmonary blood flow with a fenestrated patch. Am Heart J. 1992;123(1):260–2. Atrioventricular Septal Defect 49. Fyler DC, Buckley LP, Hellenbrand WE, et al. Endocardial cushion defect. Report of the New England Regional Infant Cardiac Program. J Pediatr. 1980;65(Suppl):441–4. 50. Samanek M. Prevalence at birth, natural risk, and survival with atrioventricular septal defect. Cardiol Young. 1991;1: 285–9.


51. Seward JB, Tajik AJ, Hagler DJ. Two-dimensional echocardiographic features of atrioventricular canal defect. In: LundstrÄm N-R, editor. Pediatric Echocardiography: Cross Sectional, M-mode and Doppler. New York: Elsevier/North Holland; 1980:197–206. 52. Silverman NH, Zuberbuhler JR, Anderson RH. Atrioventricular septal defects: cross-sectional echocardiographic and morphologic comparisons. Int J Cardiol. 1986; 13(3):309–31. 53. Anderson RH, Ho SY, Falcao S, et al. The diagnostic features of atrioventricular septal defect with common atrioventricular junction. Cardiol Young. 1998;8(1):33–49. 54. Allwork SP. Anatomical-embryological correlates in atrioventricular septal defect. Br Heart J. 1982;47(5):419–29. 55. Chan K-Y, Redington AN, Rigby ML. Color flow mapping in atrioventricular septal defects: does it have an important role in diagnosis and management? Cardiol Young. 1991; 1:315. 56. Defects in cardiac septation. In: Snider AR, Serwer AG, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby; 1997:235–97. 57. Ebels T, Anderson RH. Atrioventricular septal defect. In: Anderson RH, Macartney RF, Shinebourne EA, Baker EJ, Rigby ML, Tynan M, editors. Paediatric Cardiology. 2nd ed. Churchill Livingstone, Harcourt; 2002:939–81. 58. Mehta, et al. Echocardiographic estimation of ventricular hypoplasia in complete atrioventricular canal. Circulation. 1979;59:888. 59. Di Segni E, Edwards JE. Cleft anterior leaflet of the mitral valve with intact septa. A study of 20 cases. Am J Cardiol. 1983;51(6):919–26. 60. Minich LL, et al. Echocardiographic evaluation of atrioventricular orifice anatomy in children with atrioventricular septal defect. J Am Coll Cardiol. 19:149, 1992. 61. Rastelli GC, Kirklin JW, Titus JL. Anatomic observations on complete form of persistent common atrioventricular canal with special reference to atrioventricular valves. Mayo Clin Proc. 1966;41:296. 62. Sigfússon G, Ettedgui JA, Silverman NH, et al. Is a cleft in the anterior leaflet of an otherwise normal mitral valve an atrioventricular canal malformation? J Am Coll Cardiol. 1995;26(2):508–15. 63. Smallhorn JF, et al. Assessment of atrioventricular septal defect by two-dimensional echocardiography. Br Heart J. 1982;47:109. 64. Alivizatos P, Anderson RH, Macartney FJ, et al. Atrioventricular septal defect with balanced ventricles and malaligned atrial septum: double-outlet right atrium. Report of two cases. J Thorac Cardiovasc Surg. 1985;89(2):295–7. 65. Corwin RD, Singh AK, Karlson KE. Double-outlet right atrium: a rare endocardial cushion defect. Am Heart J. 1983;106(5 Pt 1):1156–7. 66. Horiuchi T, Saji K, Osuka Y, et al. Successful correction of double outlet left atrium associated with complete atrioventricular canal and l-loop double outlet right ventricle with stenosis of the pulmonary artery. J Cardiovasc Surg (Torino). 1976;17(2):157–61.

1711

67. Reeder GS, Danielson GK, Seward JB, et al. Fixed subaortic stenosis in atrioventricular canal defect: a Doppler echocardiographic study. J Am Coll Cardiol. 1992;20(2): 386–94. 68. Weinink ACG, et al. Correlation of morphology of the left ventricular outflow tract with two-dimensional echocardiography and magnetic resonance imaging in atrioventricular septal defect. Am J Cardiol. 1989;63:1137. 69. Uretzky G, Puga FJ, Danielson GK, et al. Complete atrioventricular canal associated with tetralogy of Fallot: Morphologic and surgical considerations. J Thorac Cardiovasc Surg. 1984;87:756–66. Inflow 70. Castaneda AR, Anderson RC, Edwards JE. Congenital mitral stenosis resulting from anomalous arcade and obstructing papillary muscles. Report of correction by use of ball valve prosthesis. Am J Cardiol. 1969;24(2):237–40. 71. Davachi F, Moller JH, Edwards JE. Diseases of the mitral valve in infancy. An anatomic analysis of 55 cases. Circulation. 1971;43(4):565–79. 72. Ranganathan M, Lam JHC, Wigle ED, et al. Morphology of the human mitral valve. II: The valve leaflets. Circulation. 1970;41:459–67. 73. Sullivan ID, Robinson PJ, de Leval M, et al. Membranous supravalvular mitral stenosis: a treatable form of congenital heart disease. J Am Coll Cardiol. 1986;8(1):159–64. 74. Shone JD, Sellers RD, Anderson RC, et al. The developmental complex of “parachute mitral valve,” supravalvular ring of left atrium, subaortic stenosis, and coarctation of aorta. Am J Cardiol. 1963;11:714–25. 75. Chung KJ, Manning JA, Lipchik EO, et al. Isolated supravalvular stenosing ring of left atrium: diagnosis before operation and successful surgical treatment. Chest. 1974;65(1):25–8. 76. Awasthy N, Radhakrishnan S, Shrivastava S. Double orifice mitral valve with PDA. JIAE, 2013:24;1:48–50. 77. Celano V, Pieroni DR, Morera JA, et al. Two-dimensional echocardiographic examination of mitral valve abnormalities associated with coarctation of the aorta. Circulation. 1984;69(5):924–32. 78. Parsons MK, Moreau GA, Graham TP Jr, et al. Echocardiographic estimation of critical left ventricular size in infants with isolated aortic valve stenosis. J Am Coll Cardiol. 1991;18(4):1049–55. 79. Garson A Jr, Bricker JT, Fisher DJ, et al. The Science and Practice of Pediatric Cardiology. 2nd ed. Williams & Wilkins; 1998:1282. 80. Collins-Nakai RL, Rosenthal A, Castaneda AR, et al. Congenital mitral stenosis. A review of 20 years’ experience. Circulation. 1977;56(6):1039–47. 81. Ruckman RN, Van Praagh R. Anatomic types of congenital mitral stenosis: report of 49 autopsy cases with consideration of diagnosis and surgical implications. Am J Cardiol. 1978;42(4):592–601. 82. Moore P, Adatia I, Spevak PJ, et al. Severe congenital mitral stenosis in infants. Circulation. 1994;89(5):2099–106.

1712


83. Collison SP, Kaushal SK, Dagar KS, et al. Supramitral ring: good prognosis in a subset of patients with congenital mitral stenosis. Ann Thorac Surg. Mar 2006;81(3):997–1001. 84. Lilliam M, Valdes-cruz, Raul OC. Echocardiographic Diagnosis of Congenital Heart Disease. Lippincott-Raven; 1999:239–43, 253–62. 85. Glancy DL, Chang MY, Dorney ER, Roberts WC. Parachute mitral valve. Further observations and associated lesions. Am J Cardiol. 1971;27(3):309–13. 86. Banerjee A, Kohl T, Silverman NH. Echocardiographic evaluation of congenital mitral valve anomalies in children. Am J Cardiol. 1995;76(17):1284–91. 87. Layman TE, Edwards JE. Anomalous mitral arcade. A type of congenital mitral insufficiency. Circulation. 1967;35(2):389–95. 88. Carpentier A, Branchini B, Cour JC, et al. Congenital malformations of the mitral valve in children. Pathology and surgical treatment. J Thorac Cardiovasc Surg. 1976;72(6):854–66. 89. Awasthy N, Tomar M, Radhakrishnan S, et al. Symptomatic giant left atrial aneurysm in a child: a rare entity Images in paediatric cardiology. 01/2010; 12(1):9–13. 90. Di Segni E, Edwards J. Cleft anterior leaflet of mitral valve with intact septa: A study of 20 cases. Am J Cardiol. 1983;51:919–26. 91. Fraisse A, Massih TA, Kreitmann B, et al. Characteristics and management of cleft mitral valve. J Am Coll Cardiol. 2003;42(11):1988–93. 92. McEnany MT, English TA, Ross DN. The congenitally cleft posterior mitral valve leaflet. An anticedent to mitral regurgitation. Ann Thorac Surg. 1973;16(3):281–92. 93. Smallhorn J, de Leval M, Stark J, et al. Isolated anterior mitral cleft: Two-dimensional echocardiographic assessment and differentiation from â€œcleftsâ€ associated with atrioventricular septal defect. Br Heart J. 1982;48:109–16. 94. Baño-Rodrigo A, Van Praagh S, Trowitzsch E, Van Praagh R. Double-orifice mitral valve: a study of 27 postmortem cases with developmental, diagnostic and surgical considerations. Am J Cardiol. 1988;61(1):152–60. 95. Trowitzsch E, Bano-Rodrigo A, Burger BM, Colan SD, Sanders SP. Two-dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol. 1985;6(2):383–7. 96. Awasthy N, Radhakrishnan S, Shrivastava S. Double orifice mitral valve with PDA. J Indian Acad Echo. 2013;24:48–50. 97. Caruso G, Cifarelli A, Balducci G, Facilone F. Ebstein’s malformation of the mitral valve in atrioventricular and ventriculoarterial concordance. Pediatr Cardiol. 1987;8(3):209–10. 98. Perloff JK, Child JS. Mitral valve prolapse. Evolution and refinement of diagnostic techniques. Circulation. 1989;80(3):710–11. 99. Freed LA, Levy D, Levine RA, et al. Prevalence and clinical outcome of mitral-valve prolapse. N Engl J Med. 1999;341(1):1–7.

100. Levine RA, Triulzi MO, Harrigan P, et al. The relationship of mitral annular shape to the diagnosis of mitral valve prolapse. Circulation. 1987;75(4):756–67. 101. Izumo M, Shiota M, Kar S, et al. Comparison of real-time three-dimensional transesophageal echocardiography to two-dimensional transesophageal echocardiography for quantification of mitral valve prolapse in patients with severe mitral regurgitation. Am J Cardiol. 2013;111(4): 588–94. 102. Vacca JB, Bussmann DW, Mudd JG. Ebstein’s anomaly. Complete review of 108 cases. Am J Cardiol. 1958;2:210–26. 103. Simcha A, Bonham-Carter RE. Ebstein’s anomaly. Clinical study of 32 patients in childhood. Br Heart J. 1971;33(1): 46–9. 104. Anderson KR, Zuberbuhler JR, Anderson RH, et al. Morphologic spectrum of Ebstein’s anomaly of the heart: a review. Mayo Clin Proc. 1979;54(3):174–80. 105. Hagler DJ. Echocardiographic assessment of Ebstein’s anomaly. Prog Pediatr Cardiol. 1993;2:28–37. 106. Gussenhoven EJ, Stewart PA, Becker AE, et al. “Offsetting” of the septal tricuspid leaflet in normal hearts and in hearts with Ebstein’s anomaly. Anatomic and echographic correlation. Am J Cardiol. 1984;54(1):172–6. 107. Celermajer DS, Cullen S, Sullivan ID, Spiegelhalter DJ, Wyse RK, Deanfield JE. Outcome in neonates with Ebstein’s anomaly. J Am Coll Cardiol. 1992;19(5):1041–6. 108. Saxena A, Lee AH, Fong LV. Functional and histological abnormalities of the left ventricle in Ebstein’s anomaly of the tricuspid valve. Indian Heart J. 1993;45(2):135–6. 109. Roberson DA, Silverman NH. Ebstein’s anomaly: echocardiographic and clinical features in the fetus and neonate. J Am Coll Cardiol. 1989;14(5):1300–7. 110. Anderson KR, Danielson GK, Mc Goon DC, et al. Ebstein’s anomaly of the left-sided tricuspid valve: pathological anatomy of the valvular formation. Circulation. 1978;58(Suppl 1):187–91. 111. Brown AK, Anderson V. Two dimensional echocardiography and the tricuspid valve. Leaflet definition and prolapse. Br Heart J. 1983;49(5):495–500. 112. Magotra RA, Agrawal NB, Mall SP, Parikh SJ. Severe dysplasia of the tricuspid valve (unguarded tricuspid anulus): clinical presentation and surgical treatment. J Thorac Cardiovasc Surg. 1990;99(1):174–5. 113. Pamuru PR, Dokuparthi MV, Remersu S, et al. Comparison of Uhl’s anomaly, right ventricular outflow tract ventricular tachycardia (RVOT VT) & arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with an insight into genetics of ARVD/C. Indian J Med Res. 2010;131:35–45. Left Ventricular Outflow Tract 114. Roberts WC. The congenitally bicuspid aortic valve. A study of 85 autopsy cases. Am J Cardiol. 1970;26(1):72–83. 115. Larson EW, Edwards WD. Risk factors for aortic dissection: a necropsy study of 161 cases. Am J Cardiol. 1984;53(6): 849–55. 116. Hoffman JI, Kaplan S. The incidence of congenital heart disease. J Am Coll Cardiol. 2002;39(12):1890–900.


117. Fernandes SM, Sanders SP, Khairy P, et al. Morphology of bicuspid aortic valve in children and adolescents. J Am Coll Cardiol. 2004;44(8):1648–51. 118. Campbell M. The natural history of congenital aortic stenosis. Br Heart J. 1968;30:514–26. 119. Methods for obtaining quantitave information from the echocardiographic examination. In: Snider AR, Serwer GA, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby year book; 1997:133–234. 120. Cape EG, Jones M, Yamada I, et al. Turbulent/ viscous interactions control Doppler/catheter pressure discrepancies in aortic stenosis. The role of the Reynolds number. Circulation. 1996;94(11):2975–81. 121. Skjaerpe T, Hegrenaes L, Hatle L. Noninvasive estimation of valve area in patients with aortic stenosis by Doppler ultrasound and two-dimensional echocardiography. Circulation. 1985;72(4):810–18. 122. Krabill KA, Ring WS, Foker JE, et al. Echocardiographic versus cardiac catheterization diagnosis of infants with congenital heart disease requiring cardiac surgery. Am J Cardiol. 1987;60(4):351–4. 123. Young JB, Quinones MA, Waggoner AD, Miller RR. Diagnosis and quantification of aortic stenosis with pulsed Doppler echocardiography. Am J Cardiol. 1980;45(5): 987–94. 124. Yeager M, Yock PG, Popp RL. Comparison of Dopplerderived pressure gradient to that determined at cardiac catheterization in adults with aortic valve stenosis: implications for management. Am J Cardiol. 1986;57(8): 644–8. 125. Oh JK, Taliercio CP, Holmes DR Jr, et al. Prediction of the severity of aortic stenosis by Doppler aortic valve area determination: prospective Doppler-catheterization correlation in 100 patients. J Am Coll Cardiol. 1988;11(6):1227–34. 126. Bonow et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology / American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the management of Patients with Valvular Heart Disease) Developed in Collaboration with the society of Cardiovascular Anesthesiologist. 10.1161/ CIRCULATIONAHA.106.176857 127. Kovalchin JP, Brook MM, Rosenthal GL, et al. Echocardiographic hemodynamic and morphometric predictors of survival after two-ventricle repair in infants with critical aortic stenosis. J Am Coll Cardiol. 1998;32(1):237–44. 128. Leung MP, McKay R, Smith A, et al. Critical aortic stenosis in early infancy. Anatomic and echocardiographic substrates of successful open valvotomy. J Thorac Cardiovasc Surg. 1991;101(3):526–35. 129. Lakier JB, Lewis AB, Heymann MA, et al. Isolated aortic stenosis in the neonate. Natural history and hemodynamic considerations. Circulation. 1974;50(4):801–8.

1713

130. Weykan AE, et al. Cross-sectional echocardiographic assessment of the severity of aortic stenosis in children. Circulation. 1977;55:773. 131. Huhta JC, Latson LA, Gutgesell HP, et al. Echocardiography in the diagnosis and management of symptomatic aortic valve stenosis in infants. Circulation. 1984;70(3): 438–44. 132. Latson LA, Cheatham JP, Gutgesell HP. Relation of the echocardiographic estimate of left ventricular size to mortality in infants with severe left ventricular outflow obstruction. Am J Cardiol. 1981;48(5):887–91. 133. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012): The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2012;33(19):2451–96. 134. Parsons MK, Moreau GA, Graham TP Jr, et al. Echocardiographic estimation of critical left ventricular size in infants with isolated aortic valve stenosis. J Am Coll Cardiol. 1991;18(4):1049–55. 135. Valdes-Cruz LM, Cayre RO. Anomalies of left ventricular outflow tract. In: Valdes-Cruz LM, Cayre RO, editors. Echocardiographic Diagnosis of Congenital Heart Disease— An Embryologic and Anatomic Approach. Philadelphia, New York: Lippincott-Raven; 1999:349–70. 136. Pachulski RT, Weinberg AL, Chan KL. Aortic aneurysm in patients with functionally normal or minimally stenotic bicuspid aortic valve. Am J Cardiol. 1991;67(8):781–2. 137. Hahn RT, Roman MJ, Mogtader AH, et al. Association of aortic dilation with regurgitant, stenotic and functionally normal bicuspid aortic valves. J Am Coll Cardiol. 1992;19(2):283–8. 138. Cheitlin MD, Fenoglio JJ Jr, McAllister HA Jr, et al. Congenital aortic stenosis secondary to dysplasia of congenital bicuspid aortic valves without commissural fusion. Am J Cardiol. 1978;42(1):102–7. 139. Beppu S, Suzuki S, Matsuda H, et al. Rapidity of progression of aortic stenosis in patients with congenital bicuspid aortic valves. Am J Cardiol. 1993;71(4):322–7. 140. Roberts WC. Valvular, Subvalvular, and supravalvular aortic stenosis: morphologic features. Cardio vase Clin. 1973:5:98–126. 141. Doty DB, Polansky DB, Jenson CB. Supravalvular aortic stenosis. Repair by extended aortoplasty. J Thorac Cardiovasc Surg. 1977;74(3):362–71. 142. Williams DE, Sahn DJ, Friedman WF. Cross-sectional echocardiographic localization of sites of left ventricular outflow tract obstruction. Am J Cardiol. 1976;37(2):250–5. 143. Newfed EA, et al. Discrete subvalvular aortic stenosis in childhood: study of 51 patients. Am J Cardiol. 1976;38:53. 144. Bengur AR, Snider AR, Serwer GA, et al. Usefulness of the Doppler mean gradient in evaluation of children with aortic valve stenosis and comparison to gradient at catheterization. Am J Cardiol. 1989;64(12): 756–61.

1714


145. Eiriksson H, Midgley FM, Karr SS, et al. Role of echocardiography in the diagnosis and surgical management of accessory mitral valve tissue causing left ventricular outflow tract obstruction. J Am Soc Echocardiogr. 1995;8(1):105–7. 146. Krueger SK, French JW, Forker AD, et al. Echocardiography in discrete subaortic stenosis. Circulation. 1979;59(3): 506–13. 147. Weyman AE, Feigenbaum H, Hurwitz RA, et al. Crosssectional echocardiography in evaluating patients with discrete subaortic stenosis. Am J Cardiol. 1976;37(3): 358–65. 148. Pierli C, Marino B, Picardo S, et al. Discrete subaortic stenosis. Surgery in children based on two-dimensional and Doppler echocardiography. Chest. 1989;96(2):325–8. 149. Maron BJ, et al. Tunnel subaortic stenosis: Left ventricular outflow tract obstruction produced by fibro muscular narrowing. Circulation. 1976;54:404. 150. Awasthy N, Marwah A, Sharma R. Congenital mitral stenosis with ventricular septal defect and pulmonary atresia : A Rare Association Indian Heart J. 2009;61: 113–4. 151. Vogt J, Rupprath G, Grimm T, et al. Qualitative and quantitative evaluation of supravalvular aortic stenosis by cross-sectional echocardiography. A report of 80 patients. Pediatr Cardiol. 1982;3(1):13–17. 152. Williams JC, Barratt-Boyes BG, Lowe JB. Supravalvular aortic stenosis. Circulation. 1961;24:1311–18. 153. Beuren AJ, Schulze C, Eberle P, et al. The syndrome of supravalvular aortic stenosis, peripheral pulmonary stenosis, mental retardation and similar facial appearance. Am J Cardiol. 1964;13:471–83. 154. Johnson LW, Fishman RA, Schneider B, et al. Familial supravalvular aortic stenosis. Report of a large family and review of the literature. Chest. 1976;70(4):494–500. 155. Freedom MR, Yoo S. Sinus of Valsalva aneurysm. In: Freedom RM, Yoo S, Mikailian H, Williams WG, editors. The Natural and Modified History of Congenital Heart Disease. Blackwell; 2004:183–5. 156. Engel PJ, Held JS, van der Bel-Kahn J, et al. Echocardiographic diagnosis of congenital sinus of Valsalva aneurysm with dissection of the interventricular septum. Circulation. 1981;63(3):705–11. 157. Shaffer EM, Snider AR, Beekman RH, et al. Sinus of Valsalva aneurysm complicating bacterial endocarditis in an infant: diagnosis with two-dimensional and Doppler echocardiography. J Am Coll Cardiol. 1987;9(3):588–91. 158. Burchell HB, Edwards JE. Aortic sinus aneurysm with communications into the right ventricle and associated ventricular septal defect. Proc Staff Meet Mayo Clin. 1951;26(18):336–40. 159. Oram S, East T. Rupture of aneurysm of aortic sinus (of Valsalva) into the right side of the heart. Br Heart J. 1955;17(4):541–51. 160. Edwards JE, Burchell HB. The pathological anatomy of deficiencies between the aortic root and the heart, including aortic sinus aneurysms. Thorax. 1957:41:26–42.

161. Kay JH, Anderson RM, Lewis RR, et al. Successful repair of sinus of Valsalva-left atrial fistula. Circulation. 1959;20: 427–9. 162. Winfield ME. Rupture of an aneurysm of the posterior sinus of Valsalva into the right atrium. Am J Cardiol. 1959;3(5):688–91. 163. Chia BL, Ee BK, Choo MH, et al. Ruptured aneurysm of sinus of Valsalva: recognition by Doppler color flow mapping. Am Heart J. 1988;115(3):686–8. 164. Peters P, Juziuk E, Gunther S. Doppler color flow mapping detection of ruptured sinus of Valsalva aneurysm. J Am Soc Echocardiogr. 1989;2(3):195–7. 165. Sakakibara S, Konno S. Congenital aneurysm of the sinus of Valsalva associated with ventricular septal defect. Anatomical aspects. Am Heart J. 1968;75(5):595–603. 166. Yokoi K, Kambe T, Ichimiya S, et al. Ruptured aneurysm of the right sinus of Valsalva: two pulsed Doppler echocardiographic studies. J Clin Ultrasound. 1981;9(9): 505–10. 167. Terdjman M, et al. Aneurysm of sinsu of Valsalva: two dimensional echocardiographic diagnosis and recognition of rupture into the right heart cavities. J Am Coll Cardiol. 1984;3:1227. 168. Cemri M, Sahinarslan A, Akinci S, et al. Dual coronary artery-pulmonary artery fistulas. Can J Cardiol. 2009; 25(3):e95. 169. Levy MJ, Lillehei CW, Anderson RC, et al. Aortico-left ventricular tunnel. Circulation. 1963;27:841–53. 170. Martins JD, Sherwood MC, Mayer JE Jr, et al. Aortico-left ventricular tunnel: 35-year experience. J Am Coll Cardiol. 2004;44(2):446–50. 171. Okoroma EO, Perry LW, Scott LP, et al. Aortico-left ventricular tunnel. Clinical profile, diagnostic features, and surgical consideration. J Thorac Cardiovasc Surg. 1976;71(2):238–44. 172. Cook AC, Fagg NL, Ho SY, et al. Echocardiographicanatomical correlations in aorto-left ventricular tunnel. Br Heart J. 1995;74(4):443–8. 173. Fripp RR, Werner JC, Whitman V, et al. Pulsed Doppler and two-dimensional echocardiographic findings in aortico-left ventricular tunnel. J Am Coll Cardiol. 1984;4(5):1012–14. 174. Rosenberg H, Williams WG, Trusler GA, et al. Congenital aortico-right atrial communications. The dilemma of differentiation from coronary-cameral fistula. J Thorac Cardiovasc Surg. 1986;91(6):841–7. Tetralogy of Fallot 175. Mitchell SC, Korones SB, Berendes HW. Congenital heart disease in 56,109 births. Incidence and natural history. Circulation. 1971;43:323–32. 176. Bound JP, Logan WF. Incidence of congenital heart disease in Blackpool 1957–1971. Br Heart J. 1977;39(4):445–50. 177. Nakazawa M, Seguchi M, Takao A. Prevalence of congenital heart disease in Japan. In: Clark EB, Takao A, editors. Developmental Cardiology: Morphogenesis and Function. Armonk, NY: Futura; 1990:541–48. 178. Dickinson DF, Arnold R, Wilkinson JL. Congenital heart disease among 160,480 liveborn children in Liverpool 1960 to 1969. Implications for surgical treatment. Br Heart J. 1981;46:55–62.


179. Perry LW, Neill CA, Ferencz C, et al. Infants with congenital heart disease: the cases. In: Ferencz C, Rubin JD, Loffredo CA, et al., editors. Perspectives in Pediatric Cardiology. Epidemiology of Congenital Heart Disease, the BaltimoreWashington Infant Study 1981–1989. Armonk, NY: Futura;1993:33–62. 180. Capelli H, Somerville J. Atypical Fallot’s tetralogy with doubly committed subarterial ventricular septal defect. Diagnostic value of 2-Dimensional echocardiography. Am J Cardiol. 1983;51(2):282–5. 181. Sanders SP, Bierman FZ, Williams RG. Conotruncal malformations: diagnosis in infancy using subxiphoid 2-dimensional echocardiography. Am J Cardiol. 1982; 50(6):1361–7. 182. Silove ED, de Giovanni JV, Shiu MF, et al. Diagnosis of right ventricular outflow obstruction in infants by cross sectional echocardiography. Br Heart J. 1983;50(5):416–20. 183. Marino B, Ballerini L, Marcelletti C, et al. Right oblique subxiphoid view for two-dimensional echocardiographic visualization of the right ventricle in congenital heart disease. Am J Cardiol. 1984;54(8):1064–8. 184. Isaaz K, Cloez JL, Marçon F, et al. Is the aorta truly dextroposed in tetralogy of Fallot? A two-dimensional echocardiographic answer. Circulation. 1986;73(5):892–9. 185. Flanagan MF, Foran RB, Van Praagh R, et al. Tetralogy of Fallot with obstruction of the ventricular septal defect: spectrum of echocardiographic findings. J Am Coll Cardiol. 1988;11(2):386–95. 186. Jureidini SB, Appleton RS, Nouri S. Detection of coronary artery abnormalities in tetralogy of Fallot by twodimensional echocardiography. J Am Coll Cardiol. 1989; 14(4):960–7. 187. Geva T, Ayres NA, Pac FA, et al. Quantitative morphometric analysis of progressive infundibular obstruction in tetralogy of Fallot. A prospective longitudinal echocardiographic study. Circulation. 1995;92(4):886–92. Double-outlet Right Ventricle 188. Neufeld HN, Lucas RV Jr, Lester RG, et al. Origin of both great vessels from the right ventricle without pulmonary stenosis. Br Heart J. 1962;24:393–408. 189. Van Praagh S, Davidoff A, Chin A, et al. Double-outlet right ventricle: anatomic types and developmental implications based on a study of 101 cases. Coeur (Paris). 1982;12: 389–439. 190. Kleinert S, Sano T, Weintraub RG, et al. Anatomic features and surgical strategies in double-outlet right ventricle. Circulation. 1997;96(4):1233–9. 191. Stellin G, Ho SY, Anderson RH, et al. The surgical anatomy of double-outlet right ventricle with concordant atrioventricular connection and noncommitted ventricular septal defect. J Thorac Cardiovasc Surg. 1991;102(6): 849–55. 192. Walters HL 3rd, Mavroudis C, Tchervenkov CI, et al. Congenital Heart Surgery Nomenclature and Database Project: double outlet right ventricle. Ann Thorac Surg. 2000;69(4 Suppl):S249–63.

1715

193. Sridaromont S, Feldt RH, Ritter DG, et al. Double outlet right ventricle: hemodynamic and anatomic correlations. Am J Cardiol. 1976;38(1):85–94. 194. Sridaromont S, Ritter DG, Feldt RH, et al. Doubleoutlet right ventricle. Anatomic and angiocardiographic correlations. Mayo Clin Proc. 1978;53(9):555–77. 195. Awasthy N, Radhakrishnan S, Sharma R. Anatomically corrected malposition of the great arteries {S, D, L} with left juxtaposition of the atrial appendages in DORV: Influence on surgical approach. World journal for pediatric & congenital heart surgery. 04/2013; 4(2): 217–19. 196. Barbero-Marcial M, Tamanati C, Jatene MB, et al. Double-outlet right ventricle with nonrelated ventricular septal defect: surgical results using the multiple patches technique. Heart Surg Forum. 1998;1(2):125–9. 197. Serraf A, Lacour-Gayet F, Houyel L, et al. Subaortic obstruction in double outlet right ventricles. Surgical considerations for anatomic repair. Circulation. 1993;88(5 Pt 2):II177–82. 198. Uemura H, Yagihara T, Kawashima Y, et al. Coronary arterial anatomy in double-outlet right ventricle with subpulmonary VSD. Ann Thorac Surg. 1995;59(3):591–7. Truncus Arteriosus 199. Collett RW, Edwards JE. Persistent truncus arteriosus; a classification according to anatomic types. Surg Clin North Am. 1949;29(4):1245–70. 200. Van Praagh R, Van Praagh S. The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications. A study of 57 necropsy cases. Am J Cardiol. 1965;16(3):406–25. 201. Rice MJ, Seward JB, Hagler DJ, et al. Visualization of aortopulmonary window by two-dimensional echocardiography. Mayo Clin Proc. 1982;57(8):482–7. Transposition of the Great Arteries 202. Van Praagh R. Transposition of the great arteries. II. Transposition clarified. Am J Cardiol. 1971;28(6):739–41. 203. Van Mierop LH. Transposition of the great arteries. I. Clarification or further confusion? Am J Cardiol. 1971;28(6):735–8. 204. Abnormalities of Ventriculoarterial connection. In: Snider AR,Serwer GA,Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby year book; 1997:296–341. 205. Tynan M, Anderson RH. Complete transposition. In: Anderson RH, Macartney RF, Shinebourne EA, Baker EJ, Rigby ML, Tynan M, editors. Paediatric Cardiology. 2nd ed. Churchill Livingstone Harcourt; 2002:1281–320. 206. Foran JP, Sullivan ID, Elliott MJ, et al. Primary arterial switch operation for transposition of the great arteries with intact ventricular septum in infants older than 21 days. J Am Coll Cardiol. 1998;31(4):883–9. 207. Baño-Rodrigo A, Quero-Jiménez M, Moreno-Granado F, et al. Wall thickness of ventricular chambers in transposition of the great arteries: surgical implications. J Thorac Cardiovasc Surg. 1980;79(4):592–7.

1716


208. Huhta JC, Edwards WD, Feldt RH, et al. Left ventricular wall thickness in complete transposition of the great arteries. J Thorac Cardiovasc Surg. 1982;84(1):97–101. 209. Davis AM, Wilkinson JL, Karl TR, et al. Transposition of the great arteries with intact ventricular septum. Arterial switch repair in patients 21 days of age or older. J Thorac Cardiovasc Surg. 1993;106(1):111–5. 210. Co-Vu JG, Ginde S, Bartz PJ, et al. Long-term outcomes of the neoaorta after arterial switch operation for transposition of the great arteries. Ann Thorac Surg. 5;2012. 211. Smith A, Wilkinson JL, Anderson RH, et al. Architecture of the ventricular mass and atrioventricular valves in complete transposition with intact septum compared with the normal: I. The left ventricle, mitral valve, and interventricular septum. Pediatr Cardiol. 1986;6(5):253–7. 212. Smith A, Wilkinson JL, Anderson RH, et al. Architecture of the ventricular mass and atrioventricular valves in complete transposition with intact septum compared with the normal: II. The right ventricle and tricuspid valve. Pediatr Cardiol. 1986;6(6):299–305. 213. Chiu IS, Anderson RH, Macartney FJ, et al. Morphologic features of an intact ventricular septum susceptible to subpulmonary obstruction in complete transposition. Am J Cardiol. 1984;53(11):1633–8. 214. Gittenberger-de Groot AC, Sauer U, Oppenheimer-Dekker A, et al. Coronary arterial anatomy in transposition of the great arteries: A morphologic study. Pediatr Cardiol. 1983;4(Suppl I):15–24. 215. Mayer JE Jr, Sanders SP, Jonas RA, et al. Coronary artery pattern and outcome of arterial switch operation for transposition of the great arteries. Circulation. 1990;82(Suppl):139–45. 216. Wernovsky G, Sanders SP. Coronary artery anatomy and transposition of the great arteries. Coron Artery Dis. 1993;4(2):148–57. 217. Quaegebeur JM. Coronary Arterial Anatomy in Transposition of the Great Arteries; an Anatomical and Clinical Study. The Arterial Switch Operation: Rationale, Results, Perspectives (thesis). Leiden: RosengaardDeerlijk;1986:43–71. 218. Anderson RH. Description of the origins and epicardial course of the coronary arteries in complete transposition. Cardiol Young. 1991;1:11–12. 219. Awasthy N, Radhakrishnan S, Iyer KS. Dual right cotonary artery. Corrected Transposition of the Great Vessels 220. Anderson RC, Lillehei CW, Lester RG. Corrected transposition of the great vessels of the heart: a review of 17 cases. Pediatrics. 1957;20(4):626–46. 221. Schiebler GL, Edwards JE, Burchell HB, et al. Congenitally corrected transposition of great vessels: a study of 35 cases. Pediatrics 35 cases. Pediatrics. 1961;27:851–88. 222. Allwork SP, Bentall HH, Becker AE, et al. Congenitally corrected transposition of the great arteries: morphologic study of 32 cases. Am J Cardiol. 1976;38(7):910–23.

223. Anderson RH. Criss-cross hearts revisited. Pediatr Cardiol. 1982;3(4):305–13. 224. Presbitero P, Somerville J, Rabajoli F, et al. Corrected transposition of the great arteries without associated defects in adult patients: clinical profile and follow up. Br Heart J. 1995;74(1):57–9. 225. Freedom RM. Discordant atrioventricular connections and congenitally corrected transposition. In: Anderson RH, Macartney RF, Shinebourne EA, Baker EJ, Rigby ML, Tynan M. Paediatric Cardiology. 2nd ed. Churchill Livingstone: Harcourt; 2002:1321–52. 226. Freedom RM, Dyck JD. Congenitally corrected transposition of great arteries. In: Moss and Adams’ Heart Diseases in Infants, Children,and Adolescents. 6th ed. Lippincott William & Wilkins;2001:1085–101. 227. Carminati M, Valsecchi O, Borghi A, et al. Cross-sectional echocardiographic study of criss-cross hearts and superoinferior ventricles. Am J Cardiol. 1987;59(1):114–8. 228. Jaffe RB. Systemic atrioventricular valve regurgitation in corrected transpositon of the great vessels. Angiographic differentiation of operable and nonoperable valve deformities. Am J Cardiol. 1976;37(3):395–402. 229. Penny DJ, Somerville J, Redington AN. Echocardiographic demonstration of important abnormalities of the mitral valve in congenitally corrected transposition. Br Heart J. 1992;68(5):498–500. 230. Marino B, Sanders SP, Parness IA, et al. Obstruction of right ventricular inflow and outflow in corrected transposition of the great arteries (S,L,L): two-dimensional echocardiographic diagnosis. J Am Coll Cardiol. 1986; 8(2):407–11. 231. Abnormalities of Ventriculoarterial connection. In: Snider AR, Serwer GA, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby year book; 1999:296–341. 232. Huhta JC, Edwards WD, Danielson GK, et al. Abnormalities of the tricuspid valve in complete transposition of the great arteries with ventricular septal defect. J Thorac Cardiovasc Surg. 1982;83(4):569–76. 233. Sim EK, Julsrud PR, van Son JA, et al. Preoperative diagnosis of coronary artery anatomy in dextrotransposition of the great arteries. Mayo Clin Proc. 1994;69(1):28–32. 234. Pasquini L, Sanders SP, Parness IA, et al. Coronary echocardiography in 406 patients with d-loop transposition of the great arteries. J Am Coll Cardiol. 1994;24(3):763–8. 235. Neil DA, Bonser RS, Townend JN. Coronary arteries from a single coronary ostium in the right coronary sinus: a previously unreported anatomy. Heart. 2000;83(5):E9. 236. Pasquini L, Parness IA, Colan SD, et al. Diagnosis of intramural coronary artery in transposition of the great arteries using two-dimensional echocardiography. Circulation. 1993;88(3):1136–41. 237. Gittenberger-de groot AC, Sauer U, Oppenheimer-Dekker A, et al. Coronary arterial anatomy in transposition of the great arteries: a morphologic study. Pediatric Cardiol. 1983;4(Suppl I):15–24.


Pulmonary Veins 238. Abnormalities of pulmonary venous return. Snider AR, Serwer AG, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby;1997:470–6. 239. Geva T, Van Praagh S. Anomalies of the pulmonary veins In: Allen JD, Gutsesell HP, Clark EB, Driscoll DJ, editors. Heart disease in Infant, Children, and Adolescents. 6th ed. Philadelphia: Lippincott Williams & Wilkins;2000:737–72. 240. Masuyama T, Lee JM, Tamai M, et al. Pulmonary venous flow velocity pattern as assessed with transthoracic pulsed Doppler echocardiography in subjects without cardiac disease. Am J Cardiol. 1991;67(16):1396–404. 241. Agata Y, Hiraishi S, Oguchi K, et al. Changes in pulmonary venous flow pattern during early neonatal life. Br Heart J. 1994;71(2):182–6. 242. Sreeram N, Walsh K. Diagnosis of total anomalous pulmonary venous drainage by Doppler color flow imaging. J Am Coll Cardiol. 1992;19(7):1577–82. 243. Snider AR, Silverman NH, Turley K, et al. Evaluation of infradiaphragmatic total anomalous pulmonary venous connection with two-dimensional echocardiography. Circulation. 1982;66(5):1129–32. 244. Smallhorn JF, Sutherland GR, Tommasini G, et al. Assessment of total anomalous pulmonary venous connection by two-dimensional echocardiography. Br Heart J. 1981;46(6):613–23. 245. Vick GW 3rd, Murphy DJ Jr, Ludomirsky A, et al. Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography. J Am Coll Cardiol. 1987;9(3):580–7. 246. Smallhorn JF, Helder P, Benson L, et al. Pulsed Doppler assessment of pulmonary vein obstruction. Am Heart J. 85:483–6. 247. Serraf A, Bruniaux J, Lacour-Gayet F, et al. Obstructed total anomalous pulmonary venous return. Toward neutralization of a major risk factor. J Thorac Cardiovasc Surg. 1991;101(4):601–6. 248. Van Praagh S, Carrera ME, Sanders S, et al. Partial or total direct pulmonary venous drainage to right atrium due to malposition of septum primum. Anatomic and echocardiographic findings and surgical treatment: a study based on 36 cases. Chest. 1995;107(6):1488–98. Systemic Veins 249. Abnormal vascular connections and structures. Snider AR, Serwer AG, Ritter SB, editors. Echocardiography in Pediatric Heart Disease. 2nd ed. St. Louis, MO: Mosby, 1997, 452–96. 250. Geva T, Van Praagh S. Abnormal systemic venous connections. In: Allen JD, Gutsesell HP, Clark EB, Driscoll DJ, editors. Moss and Adams’ Heart disease in Infant,Children, and Adolescents. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2000:773–98. 251. Huhta JC, Smallhorn JF, Macartney FJ, et al. Cross-sectional echocardiographic diagnosis of systemic venous return. Br Heart J. 1982;48(4):388–403.

1717

252. Awasthy N, Shrivastava S. Echocardiographic detection of intracardiac thrombus complicating ventriculoatrial shunt. Annals of Pediatric Cardiology 01/2009; 2(1):89–90. 253. Cohen BE, Winer HE, Kronzon I. Echocardiographic findings in patients with left superior vena cava and dilated coronary sinus. Am J Cardiol. 1979;44(1):158–61. 254. Awasthy N, Ambadkar P, Radhakrishnan S, et al. Lutembacher syndrome with unroofed left superior vena cava: a diagnostic dilemma. Pediatric Cardiol. 2012;24:1–2. 255. Awasthy N, Tomar M, Radhakrishnan S, et al. Nonsurgical management of a congenital aortocaval fistula from right subclavian artery to superior vena cava along with SVC obstruction. Pediatr Cardiol. 2011;32(2):227–9. 256. Ritter SB, Bierman FZ. Noninvasive diagnosis of interrupted inferior vena cava: gated pulsed Doppler application. Am J Cardiol. 1983;51(10):1796–8. 257. Adatia I, Gittenberger-de Groot AA. Unroofed coronary sinus and coronary sinus orifice atresia: implications for management of complex congenital heart disease. J Am Coll Cardiol. 1995;25:948. 258. Snider AR, Ports TA, Silverman NH. Venous anomalies of the coronary sinus: detection by M-mode, twodimensional and contrast echocardiography. Circulation. 1979;60(4):721–7. Coronary Artery Anomalies 259. Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn. 1990;21(1):28–40. 260. Baltaxe HA, Wixson D. The incidence of congenital anomalies of the coronary arteries in the adult population. Radiology. 1977;122(1):47–52. 261. Alexander RW, Griffith GC. Anomalies of the coronary arteries and their clinical significance. Circulation. 1956;14(5):800–5. 262. Angelini P, Villason S, Chan AV, et al. Normal and anomalous coronary arteries in humans. In: Angelini P, editor. Coronary Artery Anomalies: A Comprehensive Approach. Philadelphia: Lippincott Williams, & Wilkins;1999:27–150. 263. Angelini P, Velasco JA, Flamm S. Coronary anomalies: incidence, pathophysiology, and clinical relevance. Circulation. 2002;105(20):2449–54. 264. Hauser M. Congenital anomalies of the coronary arteries. Heart. 2005;91(9):1240–5. 265. Hutchins GM, Nazarian IH, Bulkley BH. Association of left dominant coronary arterial system with congenital bicuspid aortic valve. Am J Cardiol. 1978;42(1):57–9. 266. Johnson AD, Detwiler JH, Higgins CB. Left coronary artery anatomy in patients with bicuspid aortic valves. Br Heart J. 1978;40(5):489–93. 267. Scholz DG, Lynch JA, Willerscheidt AB, et al. Coronary arterial dominance associated with congenital bicuspid aortic valve. Arch Pathol Lab Med. 1980;104(8):417–18. 268. Ropers D, Gehling G, Pohle K, et al. Anomalous course of the left main or left anterior descending coronary artery originating from the right sinus of valsalva. Circulation. 2002;105:e42.

1718


269. King DH, Danford DA, Huhta JC, et al. Noninvasive detection of anomalous origin of the left main coronary artery from the pulmonary trunk by pulsed Doppler echocardiography. Am J Cardiol. 1985;55:608–9. 270. Shrivastava S, Casteneda AR, Moller JH. Anomalous left coronary arter from pulmonary trunk. Long-term follow-up after ligation. J Thorac Cardiovasc Surg. 1978;76(1):130–4. 271. Brooks HSJ. Two cases of an abnormal coronary artery of the heart, arising from the pulmonary artery; with some remarks upon the effect of this anomaly in producing cirsoid dilatation of the vessels. J Anat Physiol. 1885;20: 26–9. 272. Fontana RS, Edwards JE. Congenital Cardiac Disease: A Review of 357 Cases Studied Pathologically. Philadelphia: WB Saunders; 1962. 273. Bland EF, White PD, Garland J. Congenital anomalies of the coronary arteries: Report of an unusual case associated with cardiac hypertrophy. Am Heart J. 1933;8:787–801. 274. Awasthy N, Marwah A, Sharma R, et al. Anomalous origin of the left coronary artery from the pulmonary artery with patent ductus arteriosus: a must to recognize entity. Eur J Echocardiogr. 2010;11(8):E31. 275. Awasthy N, Marwah A, Sharma R. Occult anomalous origin of the left coronary artery from the pulmonary artery with ventricular septal defect. Ann Pediatr Cardiol. 2011;4(1):62–4. 276. Coe JY, Radley-Smith R, Yacoub M. Clinical and hemodynamic significance of anomalous origin of the right coronary artery from the pulmonary artery. Thorac Cardiovasc Surg. 1982;30(2):84–7. 277. Mekhiza Z, Awasthy N, Spontaneous resolution of residual mitral regurgitation in patient with ALCAPA on ECMO. World Journal for Pediatric and Congenital Heart Surgery. 10/2012;3:531–3. 278. Rajat Gupta, Shrivastava S. Anomalous right coronary artery from pulmonary artery. Ann Pediatr Cardiol. 2012 Jan–Jun;5(1):95–6. 279. Taylor AJ, Byers JP, Cheitlin MD, et al. Anomalous right or left coronary artery from the contralateral coronary sinus: “high-risk” abnormalities in the initial coronary artery course and heterogeneous clinical outcomes. Am Heart J. 1997;133(4):428–35. 280. Brandt B 3rd, Martins JB, Marcus ML. Anomalous origin of the right coronary artery from the left sinus of Valsalva. N Engl J Med. 1983;309(10):596–8. 281. Ho JS, Strickman NE. Anomalous origin of the right coronary artery from the left coronary sinus: case report and literature review. Tex Heart Inst J. 2002;29(1):37–9. 282. Jim MH, Siu CW, Ho HH, et al. Anomalous origin of the right coronary artery from the left coronary sinus is associated with early development of coronary artery disease. J Invasive Cardiol. 2004;16(9):466–8. 283. Yao CT, Wang JN, Yeh CN, et al. Isolated anomalous origin of right coronary artery from the main pulmonary artery. J Card Surg. 2005;20(5):487–9.

284. Virmani R, Chun PK, Goldstein RE, et al. Acute takeoffs of the coronary arteries along the aortic wall and congenital coronary ostial valve-like ridges: association with sudden death. J Am Coll Cardiol. 1984;3(3):766–71. 285. Basso C, Maron BJ, Corrado D, et al. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol. 2000;35(6): 1493–501. 286. Akagi T, Rose V, Benson LN, et al. Outcome of coronary artery aneurysms after Kawasaki disease. J Pediatr. 1992; 121(5 Pt 1):689–94. 287. Kato H, Koike S, Yamamoto M, et al. Coronary aneurysms in infants and young children with acute febrile mucocutaneous lymph node syndrome. J Pediatr. 1975;86(6):892–8. 288. Sakakibara S, Yokoyama M, Takao A, et al. Coronary arteriovenous fistula. Nine operated cases. Am Heart J. 1966;72(3):307–14. 289. Khatami AD, Mavroudis C, Backer CL. Congenital heart surgery nomenclature and database project: anomalies of the coronary arteries. Ann Thorac Surg. 2000;69:S270–97. 290. Amabile N, Fraisse A, Quilici J. Hypoplastic coronary artery disease: report of one case. Heart. 2005;91(2):e12. Arch Anomalies 291. Allen HD, Goldberg SJ, Sahn DJ, et al. Suprasternal notch echocardiography. Assessment of its clinical utility in pediatric cardiology. Circulation. 1977;55(4):605–12. 292. Hastreiter AR, D’Cruz IA, Cantez T, et al. Right-sided aorta. I. Occurrence of right aortic arch in various types of congenital heart disease. II. Right aortic arch, right descending aorta, and associated anomalies. Br Heart J. 1966;28(6):722–39. 293. Mathew R, Rosenthal A, Fellows K. The significance of right aortic arch in D-transposition of the great arteries. Am Heart J. 1974;87(3):314–17. 294. Knight L, Edwards JE. Right aortic arch. Types and associated cardiac anomalies. Circulation. 1974;50(5):1047–51. 295. Garti IJ, Aygen MM, Vidne B, et al. Right aortic arch with mirror-image branching causing vascular ring. A new classification of the right aortic arch patterns. Br J Radiol. 1973;46(542):115–19. 296. Drucker MH, Symbas PN. Right aortic arch with aberrant left subclavian artery: symptomatic in adulthood. Am J Surg. 1980;139(3):432–5. 297. Knight WB. Hypoplastic right retro-oesophageal aortic arch: similarities to interrupted aortic arch. Br Heart J. 1989;62(6):477–81. 298. Haughton VM, Fellows KE, Rosenbaum AE. The cervical aortic arches. Radiology. 1975;114(3):675–81. 299. Kveselis DA, Snider AR, Dick M 2nd, et al. Echocardiographic diagnosis of right aortic arch with a retroesophageal segment and left descending aorta. Am J Cardiol. 1986;57(13): 1198–9. 300. Mullins CE, Gillette PC, McNamara DG. The complex of cervical aortic arch. Pediatrics. 1973;51(2):210–15.


301. Tiraboschi R, Crupi G, Locatelli G, et al. Cervical aortic arch with aortic obstruction: report of two cases. Thorax. 1980;35(1):26–30. 302. Fyler DC, Buckley LP, Hellenbrand WE, et al. Report of the New England regional infant cardiac program. Pediatrics. 1980;65:432–6. 303. Carvalho JS, Redington AN, Shinebourne EA, et al. Continuous wave Doppler echocardiography and coarctation of the aorta: gradients and flow patterns in the assessment of severity. Br Heart J. 1990;64(2):133–7. 304. Awasthy N, Tomar M, Radhakrishnan S, et al. Constriction of juxta-ductal aorta and rapid progression of obstruction in a newborn. Ann Pediatr Cardiol. 2010;3(2):181–3. 305. Morris JH, McNamara DG. Coarctation of the aorta and interrupted aortic arch. In: Garson A, Bricker JT, Fisser DJ, Neish SR, editors. The Science and Practice of Pediatric Cardiology. Baltimore, MD: Williams & Wilkins;1998:1318–45. 306. Smallhorn JF, Huhta JC, Adams PA, et al. Cross-sectional echocardiographic assessment of coarctation in the sick neonate and infant. Br Heart J. 1983;50(4):349–61. 307. Awasthy N, Radhakrishnan S. Stepwise evaluation of left to right shunts by echocardiography. Indian heart journal 2013,65(2):201–18. 308. Riggs TW, Berry TE, Aziz KU, et al. Two-dimensional echocardiographic features of interruption of the aortic arch. Am J Cardiol. 1982;50(6):1385–90. 309. Sanders SP, MacPherson D, Yeager SB. Temporal flow velocity profile in the descending aorta in coarctation. J Am Coll Cardiol. 1986;7(3):603–9. 310. Shady RE, et al. Pulsed Doppler findings in-patients with coarctation of aorta. Circulation. 1986;73:82. 311. Simpson IA, et al. Color Doppler flow mapping in-patients with coarctation of aorta: new observations and improved evaluation with color flow diameter and proximal acceleration as predictor of severti. Circulation. 1988;77:736. 312. Celoria GC, Patton RB. Congenital absence of the aortic arch. Am Heart J. 1959;58:407–13. 313. Oppenheimer-Dekker A, Gittenberger-de Groot AC, Roozendaal H. The ductus arterious and associated cardiac anomalies in interruption of the aortic arch. Pediatr Cardiol. 1982;2(3):185–93. 314. Kutsche LM, Van Mierop LH. Anomalous origin of a pulmonary artery from the ascending aorta: associated anomalies and pathogenesis. Am J Cardiol. 1988;61(10): 850–6. 315. Nouri S, Wolverson MK. Anomalous origin of a pulmonary artery from ascending aorta. In surgery of congenital heart disease. Pediatric Cardiac Care Consortion. 1984–1985; 99–110. 316. Contro S, Miller RA, White H, et al. Bronchial obstruction due to pulmonary artery anomalies. I. Vascular sling. Circulation. 1958;17:418–23.

1719

317. Berdon WE, Baker DH, Wung JT, et al. Complete cartilagering tracheal stenosis associated with anomalous left pulmonary artery: the ring-sling complex. Radiology. 1984;152(1):57–64. 318. Jonas RA, Spevak PJ, McGill T, et al. Pulmonary artery sling: primary repair by tracheal resection in infancy. J Thorac Cardiovasc Surg. 1989;97(4):548–50. Univentricular Heart 319. Vanpraagh R, Ongley PA, Swan HJ. Anatomic types of single or common ventricle in man. Morphologic and geometric aspects of 60 necropsied cases. Am J Cardiol. 1964;13:367–86. 320. Taussig HB. A single ventricle with a diminutive outlet chamber. J Tech Methods. 1939;19:120–8. 321. Elliott LP, Anderson RC, Edwards JE. The common cardiac ventricle with transposition of the great vessels. Br Heart J. 1964;26:289–301. 322. Marshall L. Jacobs, John E. Mayer, Jr. Congenital heart surgery nomenclature and database project: single ventricle presented at the international nomenclature and database conferences for pediatric cardiac surgery, 1998–1999. Ann Thorac Surg. 2000;69:S197–204. 323. Van Praagh R, Van Praagh S, Vlad P, et al. Diagnosis of the anatomic types of single or common ventricle. Am J Cardiol. 1965;15:345. 324. Hagler DJ, Edwards WD. Univentricular atrioventricular connection. In: Emmanouilides GC, Riemenshneider TA, Allen HD, Gutgesell HP, editors. Moss and Adams Heart Disease in Infants, Children and Adolescents. 5th ed. Baltimore, MD: Williams and Wilkins;1994:1278–1306. 325. Vargas FJ, Mengo G, Gallo JP, et al. Bidirectional cavopulmonary shunt in patients with multiple risk factors. Ann Thorac Surg. 1995;60(6 Suppl):S558–62. 326 Webber SA, Uemura H, Anderson RH. Isomerism of atrial appendages. In: Anderson et al., editors. Textbook of Pediatric Cardiology. Chapter 31;813–50. 327 Gutgesell HP. Cardiac Malposition and Heterotaxy. In: Garson Jr, Bricker JT, Fischer DJ, Neish SR, editors. The Science and Practice of Pediatric Cardiology. Baltimore, MD: Williams and Wilkins, 1998. p 1539–61. 328. Ticho BS, Goldstein AM, Van Praagh R. Extracardiac anomalies in the heterotaxy syndromes with focus on anomalies of midline-associated structures. Am J Cardiol. 2000;85(6):729–34. 329 Geva T. Echocardiography and Doppler ultrasound. In: Garson Jr, Bricker JT, Fischer DJ, Neish SR, editors. The Science and Practice of Pediatric Cardiology. Baltimore, MD: Williams and Wilkins; 1997:789–843. 330. Huhta JC, Smallhorn JF, Macartney FJ. Two dimensional echocardiographic diagnosis of situs. Br Heart J. 1982; 48(2):97–108. 331. Sadiq M, Stümper O, De Giovanni JV, et al. Management and outcome of infants and children with right atrial isomerism. Heart. 1996;75(3):314–19.

1720


332 Snider AR, Serwer GA. Abnormal vascular connections and structures. In: Echocardiography in Pediatric Heart Disease. Yearbook Medical Publishers Inc.; 1990:264–99. 333. Srivastava D, Preminger T, Lock JE, et al. Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease. Circulation. 1995;92(5):1217–22. 334. Heinemann MK, Hanley FL, Van Praagh S, et al. Total anomalous pulmonary venous drainage in newborns with visceral heterotaxy. Ann Thorac Surg. 1994;57(1): 88–91. 335. Rubino M, Van Praagh S, Kadoba K, et al. Systemic and pulmonary venous connections in visceral heterotaxy with

asplenia. Diagnostic and surgical considerations based on seventy-two autopsied cases. J Thorac Cardiovasc Surg. 1995;110(3):641–50. 336. Uemura H, Ho SY, Devine WA, et al. Analysis of visceral heterotaxy according to splenic status, appendage morphology, or both. Am J Cardiol. 1995;76(11): 846–9. 337. Uemura H, Ho SY, Devine WA, et al. Atrial appendages and venoatrial connections in hearts from patients with visceral heterotaxy. Ann Thorac Surg. 1995;60(3):561–9. 338. Culbertson CB, George BL, Day RW, et al. Factors influencing survival of patients with heterotaxy syndrome undergoing the Fontan procedure. J Am Coll Cardiol. 1992;20(3):678–84.

CHAPTER 73 Real Time 3D Echocardiography for Quantification of Ventricular Volumes, Mass and Function in Children with Congenital and Acquired Heart Diseases Shuping Ge, Jie Sun, Lindsay Rogers, Rula Balluz

Snapshot ¾¾ Left Ventricular Volumes, Ejection Fraction, and Mass ¾¾ Right Ventricular Volumes, Ejection Fraction, and Mass ¾¾ Single Ventricular Volumes, Ejection Fraction, and Mass

INTRODUCTION The advent of real time three-dimensional echocar diography (RT3DE) is a major milestone in the evolution of echocardiography. RT3DE has been used to generate three-dimensional (3D) views of cardiac structures in an intuitive and object format, obviating the need to mentally create 3D images based on sweeps by two-dimensional echocardiography (2DE). Furthermore, RT3DE provides an opportunity to quantitatively measure distances, areas, volumes to quantify the cardiac structures, flows, and function in 3D that may not possible by 2DE. A query of “3D echocardiography” yields over 4,500 publications in PubMed database. Therefore, the focus of this chapter is the use of RT3DE to quantitatively assess ventricular volumes, mass, and function in children with congenital and acquired heart diseases. Other related topics can be found in other chapters of this book.

¾¾ Three-Dimensional Analysis of Regional Wall Motion,

Synchrony, and Strain ¾¾ Future Perspectives

Quantitative measurement of left ventricular (LV) volumes, mass, and function is one of the most common and important indications for echocardiography. These measurements are among the most powerful tools for diagnosis and prognosis of congenital and acquired heart diseases and for assessment of medical, percutaneous, and surgical interventions. Awareness is also growing of the importance of right ventricular (RV) volume, mass, and function in many cardiopulmonary diseases. Furthermore, there are challenges and opportunities to measure the volume, mass, and function of complex chambers such as the left atrium, right atrium, and the univentricular heart. As echocardiography continues to be the imaging modality of choice for these measurements, the strengths and limitations of M-mode, two-dimensional (2D), and recently 3D echocardiographic methodologies for accurate and reproducible measurement of these indices have been extensively investigated for congenital and acquired heart diseases.

1722


Evidence suggests that 3DE provides improved accuracy and reproducibility over 2D methods for measu rement of LV volume and function calculation in adults1–3 and in children.4–10 Data have accumulated on the utility of 3DE for measuring chamber volumes and function for the RV, and for the single ventricle,2,11–14 which may become more widely used in clinical and research arenas in the future. Finally, new advanced modes of analysis such as 3D strain and synchrony analysis by 3DE are promising methodologies that warrant further investigation.

LEFT VENTRICULAR VOLUMES, EJECTION FRACTION, AND MASS The utilization of echocardiography to assess LV chamber size and function dates to the advent of this technology. Popp et al.15 reported on the change of cardiac dimensions using M-mode echocardiography. Feigenbaum et al.16 used these changes to assess LV function and correlated it to angiography. The correlation appeared good except in cases with dilatation and regional wall abnormalities. The development of 2DE allowed the utilization of LV area and the LV long axis to estimate volume. Wyatt et al.17,18 showed that this technique was superior to M-mode, especially in asymmetrical hearts. This technique is limited by the fact that 3D measurements are extrapolated from 2D-acquired data using geometrical assumptions. Also, on-axis crosssectional images may not be accurate because the whole surface of the heart is not visualized. Finally, there may be problems with foreshortening the long axis of the ventricle. The logical next step is the development of 3D constructions of the LV to assess volumes and function. Dekker et al.19 first attempted to create 3D images with a mechanical arm, which resulted in creating a 3D model of the LV. Many investigators also published measurements of LV volumes using similar techniques with in vivo validation using animal and human models.20–25 The ability of 3D technology to overcome geometric assum ptions, avoid image positioning errors, and provide a surface reconstruction algorithm was the basis for this improvement, as confirmed by many subsequent studies.26–29 The advent of RT3DE generated a renewed enthusiasm for potential clinical use in the adult population. RT3DE has been shown to have excellent correlations with cardiac magnetic resonance imaging (CMR) for assessing chamber volumes and ejection fraction (EF) in adults,

Fig. 73.1: Semiautomated three-dimensional echocardiography (3DE) algorithm for measurement of LVEDV, LVESV, and left ventricular ejection fraction (LVEF). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Adapted from Ref. 96.

but it underestimates LV volumes with insignificant difference for the EF between the two modalities. Most studies found the differences in volume calculations to be more significant with dilated and abnormal ventricles.30 Some experts propose including the endocardial surface with the trabeculations to improve the correlation with CMR.31–33 Others suggest increasing the number of planes to better delineate the endocardial surface in an attempt to eliminate geometric assumptions, especially in abnormal ventricles.34,35 Others have had more success using direct volumetric measurement through the use of semiautomated border detection (Fig. 73.1). RT3DE has also been applied in adults with congenital heart disease for measurement of LV volumes. van den Bosch et al.36 studied 32 patients ranging in age from 19–51 years with complex congenital heart disease, including tetralogy of Fallot, RV obstructive lesions, and transposition of the great vessels after atrial switch surgery. Compared with CMR, RT3DE underestimated LV volume, but the difference was not statistically significant. These investigators found good correlations in LVEDV, LVESV, and left ventricular ejection fraction (LVEF) between RT3DE by manual border detection and CMR, with correlation coefficients (r) = 0.98, 0.97, and 0.94, respectively. Correlations in LVEDV, LVESV, and EF were modest between CMR and RT3DE using automatic border detection in this study of ventricles with altered geometries (r = 0.79, 0.83, and 0.54, respectively).

Chapter 73: Real Time 3D Echocardiography for Quantification of Ventricular Volumes, Mass and Function in Children

Left Ventricular Mass RT3DE has also been used for the assessment of LV mass. The technique requires identification of both endocardial and epicardial borders. This has made estimation of LV mass more challenging in adult studies. A major challenge is the difficulty in visualizing the apex for mass calculation. However, validation studies showed better correlation between RT3DE and CMR compared with estimating LV mass estimation using M-mode or 2D methods, which have been reproduced in many adult studies.37,38

Meta-Analysis Shimada and Shiota39 conducted a meta-analysis to assess the sources of errors in evaluation of the LV by 3DE. Their analysis included 3,055 subjects in 95 studies. The study showed significant underestimation bias of both LVEDV and LVESV by RT3DE compared with CMR. The bias for estimation of LVEF was not statistically significant. Sources of error included female sex and presence of congenital heart disease, which were associated with more underestimation in the analysis. Semiautomatic border detection and the use of matrix-array transducer were associated with less underestimation. Despite the differences between RT3DE volumetric estimation of the LV and CMR, the literature supports the role of RT3DE as both accurate and reproducible in assessing LV volume and LVEF, although it is not interchangeable with other radiological modalities. Shimada and Shiota40 published another meta-analysis evaluating the use of RT3DE to assess LV mass. This analysis assessed 25 studies including 671 comparisons. Studies published in 2004 or earlier showed high heterogeneity [I(2) = 69%)] and significant underestimation of LV mass by 3DE (−5.7 g, 95% confidence interval −11.3 to −0.2, P = 0.04). Studies published between 2005 and 2007 were still heterogeneous [(I(2) = 60%)] but showed less systematic bias (−0.5 g, 95% confidence interval −2.5 to 1.5, P = 0.63). In contrast, studies published in 2008 or later were highly homogeneous [(I(2) = 3%)] and showed excellent accuracy (−0.1 g, 95% confidence interval −2.2 to 1.9, P = 0.90). Investigation of factors affecting the bias revealed that evaluation of cardiac patients compared with healthy volunteers led to greater bias (P < 0.05). In conclusion, this meta-analysis elucidates the underestimation of LV mass by 3DE, improvement of the technique over the past decade, and factors affecting the degree of bias. These data

1723

provide a detailed basis for improving the accuracy of 3DE, an indispensable step toward further clinical application. Currently, for transthoracic and transesophageal assessment of LV volumes and EF, 3DE is recommended over the use of 2DE, as 3DE has been clearly demonstrated to provide more accurate and reproducible measurements.2

Left Ventricle Analysis in Children Although M-mode and 2DE recordings are widely used to assess LV size, mass, and global systolic function in children with congenital and acquired heart disease, in many defects LV or ventricular septal geometric or functional alterations diminish the accuracy and reproducibility of these measurements. Many validation studies have demonstrated that 3DE compares favorably with other independent reference standards such as CMR and is superior for assessing LV volumes, mass, and EF in children as well as adults (Table 73.1). Since our first validation of RT3DE by CMR,4 seven RT3DE studies have been published comparing measurements of LV volumes, mass, and EF with CMR measurements.4–10 These reports showed excellent correlation, agreement, and reproducibility for volumes and mass between the two modalities but only modest advantages in measurement of EF. We have also found that RT3DE using a semiautomated method is more accurate and reproducible than M-mode or Simpson’s 2D biplane method and is as efficient as 2DE in children.6 These findings suggest that the American Society of Echocardiography’s recommendation that in adults LV should be quantified using RT3DE may also be applied to children.1,2 Studies of LV mass assessment in children are very limited. However, the available studies report excellent correlations between RT3DE and CMR, although RT3DE overestimated LV mass in comparison to CMR in most of these studies. Inter- and intraobserver variability in this assessment are excellent.4,6–8 These data suggest that RT3DE quantification of LV mass is feasible for clinical applications, although the normal ranges of LV volumes, mass, and EF in various age groups must still be defined.

RIGHT VENTRICULAR VOLUMES, EJECTION FRACTION, AND MASS Because of the complex geometry of the right ventricle, clinical assessment of its size, mass, and EF has largely been qualitative. However, the importance of RV chamber size and systolic function has increasingly been

1724


Table 73.1: Real Time Three-Dimensional Echocardiography for Left Ventricle Volumes, Mass, and Function in Children

RT3DE Compared With Other Method

Methods

LV Indices

Correlation

19

CMR

Long-axis, eight planes

LVEDV, LVESV, LV mass, LVEF, SV

r = 0.86–0.97

2007

25

LV angiography

Semiautomated

LVEDV and LVES

r = 0.979–0.996

Lu et al.6

2008

20

CMR

Four-plane, eightplane semiautomated


r = 0.85–0.9

Riehle et al.7

2008

12

CMR

Semiautomated


r = 0.93–0.99, 0.69 for EF

Friedberg et al.8

2010

35

CMR

Disc summation

LVEDV, LVESV, LVEF

r = 0.90–0.96

Hascoët et al.9

2010

50

RT3DE

Semiautomated (Qlab vs. TomTec)


r > 0.97 but 0.79 for EF

Laser et al.10

2010

49

CMR

2 Ultrasound systems/ semiautomated

LVEDV and LVESV

r = 0.91–0.95

Reference

Year

Number of Patients

Bu et al.4

2005

Iino et al.5

(CMR: Cardiac magnetic resonance imaging; EF: Ejection fraction; LV: Left ventricle; LVEDV: Left ventricular end-diastolic volume LVEF: Left ventricular ejection fraction; LVESV: Left ventricular end-systolic volume; RT3DE: Real time three-dimensional echocardiography; SV: Stroke volume).

recognized in both pediatric and adult heart disease. Many volume and pressure overloading conditions can cause remodeling and dysfunction of the RV. Studies in children who have undergone repair of tetralogy of Fallot have shown that longitudinal follow-up of right and left ventricular remodeling and dysfunction are crucial to guide timely intervention to replace the pulmonary valve to avoid failure of the RV, arrhythmia, and sudden cardiac death. Although CMR has been established as a clinical standard for quantitative analysis of the RV, quantitative RT3DE may be useful in many instances, for example, as a potential screening tool and in those in whom CMR is contraindicated or not available. Because of the cost, portability, and availability of RT3DE and the growing evidence of the utility of RV3DE, the application of RV3DE for quantitative analysis of the RV may increase in the future. Unlike the LV, there is no established geometric model that can be used for quantitative analysis of RV volumes, mass, and function. Clinical evaluation of RV size and function is largely qualitative for both adults and children. Quantitative analysis of the RV becomes a major potential application for 3DE, especially since RT3DE hardware and software have become available. Initial validation studies of RV volumes and EF quantification by 3DE were based

on in vitro and in vivo models.41–47 Multiple clinical studies in adults followed, comparing RT3DE volumes with CMR.48–53

Right Ventricle Analysis in Children and in Patients with Congenital Heart Disease Our group11 used a disc-summation method (Figs 73.2A and B) and studied 20 normal children between the ages of 6 and 18 years comparing RV volumes and function obtained with RT3DE versus CMR. We found excellent correlation between RT3DE and CMR, with correlation coefficients of 0.96, 0.98, and 0.89 for RVESV, RVEDV, and RVEF, respectively. We also found good inter- and intraobserver variability. There was small but significant underestimation of RV volume, especially RVEDV, by RT3DE compared with CMR. The differences were not statistically significant for RVESV and RVEF. Niemann et al.12 used a Beutel semiautomated method (Fig. 73.2C) to study 17 adults and 16 children with congenital heart disease, including tetralogy of Fallot, transposition of the great arteries, truncus arteriosus, atrial septal defect, ventricular septal defect (VSD), coarctation


1725

A

B

C

Figs 73.2A to C: (A) The disc summation method for measurement of right ventricular (RV) volumes and ejection fraction (EF) in children. Manual tracing of the RV endocardial contours was performed on a stack of short-axis images. The four-chamber views and coronal views are used as reference images; (B) Simpson’s principle is used to derive RVEDV, RVESV, and right ventricular ejection fraction (RVEF); (C) The semiautomated method for measurement of the RV indices. The method is based on the Beutel model with manual tracing of the RV endocardial land marks, including a set of coronal, sagittal, and four-chamber views. (LV: Left ventricle; RV: Right ventricle). Source: Adapted from Ref. 96.

of the aorta, and atrioventricular septal defect. They used a semiautomated border detection method in comparison with CMR. Excellent correlation was obtained, with corre lation coefficients of 0.99 for RVESV, 0.95 for RVEDV, and 0.97 for EF. Therefore, as seen in adults with cardiovascular disease, including congenital heart disease,54–59 quanti tative analysis of RV volumes and EF using RT3DE is also feasible in children. The limitations of RT3DE for quanti tative analysis of the RV are related to image quality, border clarity, and the difficulty imaging the entire RV, especially in patients with an enlarged RV, such as those who have undergone repair of tetralogy of Fallot.

Meta-Analysis Shimada et al.60 performed a meta-analysis of published studies comparing assessment of RV volumes and EF by RT3DE versus CMR. The analysis included 23 studies and 807 adults and children. They concluded that compared with CMR, 3DE significantly underestimated RVESV,

RVEDV, and EF, particularly in patients with larger volumes (> 200 mL) and in younger patients (≤18 years). There was no improvement for the analysis with time. The use of matrix-array transducer did not improve the correlation either. There was no statistical difference with the use of automated compared with manual border detection. Although RT3DE is highly promising for the evaluation of RV indices, further investigation is warranted to address the limited feasibility and accuracy before widespread clinical application.2

SINGLE VENTRICULAR VOLUMES, EJECTION FRACTION, AND MASS One of the most complex types of congenital heart disease in children is the functional single ventricle. These patients often require two to three stages of palliation, ultimately resulting in a Fontan type of palliation, and they often have long-term structural and functional compli cations, arrhythmias, exercise intolerance, and limited

1726


neurodevelopmental outcomes. RT3DE requires no geo metric assumptions and is ideally suited for quantification of volumes and EF for this type of congenital heart disease. Altmann et al.61 first used acoustic spatial locator 3D reconstructive technology to assess the volume and EF of single ventricles with LV morphology in comparison with 2DE and CMR. They studied 12 patients and showed superior agreement with less data scatter in ESV, EDV, mass, and EF between 3DE (bias 3.4 ± 5.5 mL, 14.2 ± 8.3 mL, 5.8 ± 8.4 g, and 4.4% ± 5.3%, respectively) and CMR than between 2DE and CMR (−2.9 ± 8.1 mL, 2.9 ± 10.4 mL, −8.3 ± 12.0 g, and 8.5% ± 10.3%, respectively). The interand intraobserver variabilities were more favorable for 3DE (5.7–7.1%) compared with CMR than for 2D compared with CMR (10–24%). Altmann et al. concluded that 3DE provides estimates of ventricular volumes, EF, and mass that are comparable to CMR in this select group of patients with single ventricles of LV morphology. Soriano et al.62 applied RT3DE for the estimation of volumes, mass, and EF in patients with single ventricles using a disc-summation technique. RT3DE was feasible in 27 of 29 patients (93%). The RT3DE EDV correlated well but was smaller than with CMR, and 3DE EF was smaller than with CMR. There was no significant difference in measurements of ESV or mass. The 3DE interobserver differences for mass and volumes were not significant except for measurement of EF. Intraobserver differences were not significant. They speculated that the modest correlation in EF between RT3DE and CMR was related in part to the small range of EFs in this single-ventricle population. This study suggested that RT3DE quanti fication of EDV, ESV, mass, and EF in patients with single ventricles is feasible, reproducible, and reasonably accurate, except in measurement of EF, and warrants further validation. We showed that a long-axis, eight-plane Simpson’s technique is also feasible to assess volumes and EF for the functional single ventricle. Furthermore, our study showed that EF values are an independent predictor of transplantfree survival for this group. EF < 40% is associated with significantly lower freedom of transplant-free survival in this group of patients.14

THREE-DIMENSIONAL ANALYSIS OF REGIONAL WALL MOTION, SYNCHRONY, AND STRAIN Regional Wall Motion and Synchrony The capability of RT3DE to capture the entire LV in three dimensions offers the opportunity not only to assess

global LV function more accurately and reproducibly but also to quantify the regional function of the 16 LV segments and to assess LV intraventricular synchrony. To analyze LV regional function and synchrony, the cyclic changes of the volumes of each of the 16 LV segments are plotted against time over the course of the cardiac cycle. The volume curves and plots allow measurement of volume changes of each segment (i.e. segmental motion) and temporal differences of each segment to minimum volume (i.e. synchrony). Regional minimal volume (i.e. maximal contraction) normally occurs at the same time in ventricular systole for all segments. The systolic dyssyn chrony index (SDI) is calculated as the standard deviation of time to regional minimal volume of the segments. Studies in the pediatric literature have validated use of this new technology to assess LV synchrony in volume and pressure loading conditions, the effect of ventricular septal patch repair to LV synchrony, and outcome of resynchronization therapy in patients with a single ventricle with LV morphology. Kobayashi et al.63 prospectively studied 27 children with end-stage renal disease (13 on peritoneal dialysis and 14 on hemodialysis) and 29 normal controls. SDI was normalized to cardiac cycle duration (SDIp). SDIp (16 segments) and LV mass were significantly greater in the hemodialysis group. SDI and SDIp (16 segments) improved after a hemodialysis session (P < 0.05); LV mass and LV mass index remained unchanged. LV dyssynchrony was significantly greater in patients with LV hypertrophy compared with those without. Their study demonstrated an association between LV volume load and LV hypertrophy with significant LV dyssynchrony in end-stage renal disease. SDI may provide a sensitive marker for mechanistic and early detection of LV dysfunction. Veeram et al.64 studied patients with large VSDs who underwent surgical patch closure during infancy to investigate the long-term effects of the presence of akinetic patch in the ventricular septum and postoperative right bundle branch block (RBBB) on LV mechanical synchrony and global systolic function. Their study showed that pediatric patients 5–10 years after VSD patch closure have normal LV function. The presence of the RBBB was associated with mechanical dyssynchrony and tendency toward LV dilatation in this group of patients. They demonstrated that RT3DE is a sensitive technique for assessing LV synchrony in postoperative VSD patients, especially those with RBBB, who require long-term follow-up for potential complications. Finally, Bacha et al.65 performed multisite pacing studies in 26 patients undergoing stepwise single-ventricle


A

1727

B

Figs 73.3A and B: Three-dimensional speckle tracking echocardiography (3DSTE) offline analysis. The endocardial borders were manually traced at left ventricle (LV) end-diastole and end-systole from the apical four-chamber, two-chamber, and LV long-axis views, respectively. The LVEDV, LVESV, left ventricular ejection fraction (LVEF), systolic dyssynchrony index (SDI), LV three-dimensional (3D) systolic peak global (A) and segmental strain (B) were automatically calculated by the software. The mean systolic 3D peak strain of the 16 segments represented LV global strain. The mean basal, mid, and apical segmental systolic 3D peak strain represented the LV segmental peak systolic strain, respectively. The 3D strain indices derived included global systolic strain (GSS); global longitudinal systolic strain (GLSS); systolic strain of basal, middle, and apical segments. Source: Adapted from Ref. 96.

palliation. RT3DE was used in 10 subjects. They observed significant response to multisite pacing, including (a) improvement in QRS duration in 24 of 26 patients (93.9 ± 17.5 ms vs 71.7 ± 10.8 ms; P < 0.001); (b) increase in systolic blood pressure in 25 of 26 patients (86.3 ± 20.0 mm Hg vs 93.8 ± 20.2 mm Hg; P < 0.001); (c) increase in cardiac index in 21 of 22 patients (3.2 ± 0.8 vs 3.7 ± 1.0 L × min−1 × m−2; P < 0.001); and (c) improvement in index of asynchrony in 8 of 10 patients (10.3 ± 4.8 vs 6.0 ± 1.4; P < 0.04). The study suggests that RT3DE is potentially useful in assessing cardiac resynchronization therapy even in cases with complex geometries.

Strain Analysis by Real time Three-Dimensional Echocardiography Conventional indices of regional and global ventricular function, defined by endocardial excursion, such as fractional shortening and EF, are considered to be loaddependent.66,67 Myocardial velocities by tissue Doppler imaging (TDI) do not rely on geometric assumptions but are inherently unidimensional, angle-dependent, variable with aging, and influenced by anthropometrics and heart rate.68,69 Myocardial strain has been shown to be more robust for assessment of regional ventricular myocardial function using both echocardiography and CMR.70–74 TDIbased strain analysis has been extensively validated and has been shown to be limited as a one-dimensional and

angle-dependent method.70 Recently, three-dimensional speckle tracking echocardiography (2DSTE) has been introduced as a new method to quantify myocardial strain. This technique measures myocardial deformation by means of frame-by-frame tracking and motion analysis of speckles within B-mode images. Validation studies with tagged CMR and sonomicrometry in adults70,71 and children75,76 have provided evidence that 2DSTE is a reliable method for determining ventricular myocardial function. 2DSTE has many limitations, however. Firstly, myocardial deformation measurement by 2DSTE is affected by loss of speckles due to motion outside the imaging plane.77 Secondly, 2DSTE has limited reproducibility, likely owing to the variabilities in the choice of image planes and lack of standardization in image analysis.78 Finally, the analysis is cumbersome and six planes are needed for complete analysis, which is a major limitation for automation and potential clinical use. More recently, the advent of three-dimensional speckle tracking echocardiography (3DSTE) (Figs 73.3A and B) has shown the potential to overcome the limitations of 2DSTE imaging for the assessment of LV global and regional systolic function. This method tracks the motion of speckles within the scan volume, allowing more complete and accurate assessment of myocardial deformation in 3D space79–82 by avoiding the loss of speckles due to out-of-plane motion. 3DSTE has been validated for the quantification of LV volumes82 and LV wall

1728


motion in ischemic heart disease83 in adults. Nonetheless, data are scarce and incomplete for children with or without congenital heart disease.75,76,84 Thus, feasibility, reproducibility, maturational changes, and normal values in this population must be shown before these indices can be used for assessing LV function for diagnosis, prognosis, and risk stratification of various congenital and acquired heart diseases in the young before and after medical, percutaneous, and surgical intervention. We used RT3DE to study 256 consecutive healthy subjects using full-volume 3D data acquisition with a 3D matrix-array transducer.85 Study subjects were divided into five age groups: group 1 (birth to age 1 year); group 2 (1–5 years); group 3 (6–9 years); group 4 (10–13 years); and group 5 (14–18 years). The 3D LV global strain (GS), global longitudinal peak systolic strain (GLS), global radial peak systolic strain (GRS), and global circumferential peak systolic strain (GCS) values were determined using modality-independent software. A total of 228 cases (89%) were adequate for analysis and 28 cases (11%) were excluded, including 10 cases excluded owing to the low frame rates as determined by the system and 18 cases excluded owing to poor 3D images. We found statistically significant differences among the five age groups for GLS and GCS, but no statistical difference between the age groups for GRS and GS values. Multiple linear regression analyses showed that LV and RV dimension, mass, volume, and EF were significantly associated with GLS, GS, GRS, and GCS. The interobserver variability of 3D systolic strain parameters ranged from 1.2% to 9.5%, and intraobserver variability ranged from 0.5% to 3.8%. Our study concluded that global 3D systolic strain measurement using the new 3D RT STE is feasible and reproducible in children. GLS and GCS are higher in early puberty and lower in late puberty compared with infancy and early childhood. GRS and GS have no maturational changes. Future work will define the z scores for these measurements and in various congenital and acquired heart diseases for potential clinical application and research. To use this new methodology to evaluate LV strain and function, Saltijeral et al.86 evaluated 30 consecutive, nonselected obese children and 42 healthy volunteer children using a similar RT3DE wall motion tracking method. They found statistically significant differences in interventricular septum thickness, LV posterior wall thickness, LVEDV, LVESV, left atrium volume, LV mass, and lateral annulus peak velocity between the groups as well as in all the 3D wall motion tracking variables. By multivariate logistic regression analysis, the strongest relationship with

obesity was found for LV average circumferential strain (b coefficient = 0.74; r2 = 0.55; P = 0.003). Their data suggested that obesity-related cardiomyopathy is associated not only with structural cardiac changes but also with myocardial deformation changes in the childhood. Assessment of LV circumferential strain using 3D wall motion tracking is a marker with promising sensitivity for identifying obesity-related cardiomyopathy. The limitations of this technology include limited spatial and temporal resolution of the 3DE data sets and the variability in the measurements secondary to the hardware, software, and algorithms provided by various vendors. Further validation, improvement, and standar dization are warranted for clinical application.

FUTURE PERSPECTIVES Much evidence suggests that in the presence of adequate image quality, LV volumes, mass, and EF measurements by 3DE agree more closely with CMR measurements and have better reproducibility than does 2DE, making 3DE the modality of choice for the everyday clinical evaluation of LV volumes and EF. Quantitative analysis of volumes, mass, and EF for the RV and for single ventricles holds great promise and warrants future investigation. New modes of regional wall motion, strain, and LV dyssynchrony assessment using RT3DE are in the forefront of active research. Future advancements in hardware are expected to allow acquisition of wide-angle 3D data from the entire heart in a single cardiac cycle, with higher spatial and temporal resolution. We anticipate that further development in automatic quantitative analysis algorithms and software will make RT3DE an integral clinical methodology for diagnosis, prognosis, and assessment of medical, percutaneous, and surgical intervention for congenital heart disease.87

REFERENCES 1. Hung J, Lang R, Flachskampf F, et al. ASE. 3D echocardi ography: a review of the current status and future directions. J Am Soc Echocardiogr. 2007;20(3):213–33. 2. Lang RM, Badano LP, Tsang W, et al. American Society of Echocardiography; European Association of Echocar diography. EAE/ASE recommendations for image acquisition and display using three-dimensional echocardi ography. J Am Soc Echocardiogr. 2012;25(1):3–46. 3. Mor-Avi V, Jenkins C, Kühl HP, et al. Real-time 3-dimen sional echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error. JACC Cardiovasc Imaging. 2008;1(4):413–23.


4. Bu L, Munns S, Zhang H, et al. Rapid full volume data acquisition by real-time 3-dimensional echocardiography for assessment of left ventricular indexes in children: a validation study compared with magnetic resonance imaging. J Am Soc Echocardiogr. 2005;18(4):299–305. 5. Iino M, Shiraishi H, Ichihashi K, et al. Volume measu rement of the left ventricle in children using real-time three-dimensional echocardiography: comparison with ventriculography. J Cardiol. 2007;49(5):221–9. 6. Lu X, Xie M, Tomberlin D, et al. How accurately, reprod ucibly, and efficiently can we measure left ventricular indices using M-mode, 2-dimensional, and 3-dimensional echocardiography in children? Am Heart J. 2008;155(5): 946–53. 7. Riehle TJ, Mahle WT, Parks WJ, et al. Real-time threedimensional echocardiographic acquisition and quanti fication of left ventricular indices in children and young adults with congenital heart disease: comparison with magnetic resonance imaging. J Am Soc Echocardiogr. 2008;21(1):78–83. 8. Friedberg MK, Su X, Tworetzky W, et al. Validation of 3D echocardiographic assessment of left ventricular volumes, mass, and ejection fraction in neonates and infants with congenital heart disease: a comparison study with cardiac MRI. Circ Cardiovasc Imaging. 2010;3(6):735–42. 9. Hascoët S, Brierre G, Caudron G, et al. Assessment of left ventricular volumes and function by real time threedimensional echocardiography in a pediatric population: a TomTec versus QLAB comparison. Echocardiography. 2010;27(10):1263–73. 10. Laser KT, Bunge M, Hauffe P, et al. Left ventricular volumetry in healthy children and adolescents: comparison of two different real-time three-dimensional matrix transducers with cardiovascular magnetic resonance. Eur J Echo cardiogr. 2010;11(2):138–48. 11. Lu X, Nadvoretskiy V, Bu L, et al. Accuracy and reprodu cibility of real-time three-dimensional echocardiography for assessment of right ventricular volumes and ejection fraction in children. J Am Soc Echocardiogr. 2008;21(1): 84–9. 12. Niemann PS, Pinho L, Balbach T, et al. Anatomically oriented right ventricular volume measurements with dynamic three-dimensional echocardiography validated by 3-Tesla magnetic resonance imaging. J Am Coll Cardiol. 2007;50(17):1668–76. 13. Soriano BD, Hoch M, Ithuralde A, et al. Matrix-array 3-dimensional echocardiographic assessment of volumes, mass, and ejection fraction in young pediatric patients with a functional single ventricle: a comparison study with cardiac magnetic resonance. Circulation. 2008;117(14):1842–8. 14. Fu M, Choi G, Xie MX, et al. Quantitative real-time 3D echocardiography predicts adverse outcomes in func tional single ventricle patients. J Am Soc Echocardiogr. 2010;23:B54. 15. Popp RL, Wolfe SB, Hirata T, Feigenbaum H. Estimation of right and left ventricular size by ultrasound. A study of the echoes from the interventricular septum. Am J Cardiol. 1969;24(4):523–30.

1729

16. Feigenbaum H, Popp RL, Wolfe SB, et al. Ultrasound measurements of the left ventricle. A correlative study with angiocardiography. Arch Intern Med. 1972;129(3):461–7. 17. Wyatt HL, Heng MK, Meerbaum S, et al. Cross-sectional echocardiography. II. Analysis of mathematic models for quantifying volume of the formalin-fixed left ventricle. Circulation. 1980;61(6):1119–25. 18. Wyatt HL, Meerbaum S, Heng MK, Gueret P, Corday E. Cross-sectional echocardiography. III. Analysis of mathe matic models for quantifying volume of symmetric and asymmetric left ventricles. Am Heart J. 1980;100 (6Pt 1):821–8. 19. Dekker DL, Piziali RL, Dong E Jr. A system for ultrasonically imaging the human heart in three dimensions. Comput Biomed Res. 1974;7(6):544–53. 20. Ghosh A, Nanda NC, Maurer G. Three-dimensional reconstruction of echo-cardiographic images using the rotation method. Ultrasound Med Biol. 1982;8(6):655–61. 21. Ariet M, Geiser EA, Lupkiewicz SM, et al. Evaluation of a three-dimensional reconstruction to compute left ventri cular volume and mass. Am J Cardiol. 1984;54(3):415–20. 22. Moritz WE, Pearlman AS, McCabe DH, et al. An ultrasonic technique for imaging the ventricle in three dimensions and calculating its volume. IEEE Trans Biomed Eng. 1983;30(8):482–92. 23. Sapin PM, Schroder KM, Gopal AS, et al. Comparison of two- and three-dimensional echocardiography with cineventriculography for measurement of left ventricular volume in patients. J Am Coll Cardiol. 1994;24:1054–63. 24. Keller AM. Positional localization: three-dimensional transthoracic echocardiographic techniques for the measurement of cardiac mass, volume, and function. Echocardiography. 2000;17(8):745–8. 25. Gopal AS, Schnellbaecher MJ, Shen Z, et al. Freehand three-dimensional echocardiography for determination of left ventricular volume and mass in patients with abnormal ventricles: comparison with magnetic resonance imaging. J Am Soc Echocardiogr. 1997;10(8):853–61. 26. Siu SC, Rivera JM, Guerrero JL, et al. Three-dimensional echocardiography. In vivo validation for left ventricular volume and function. Circulation. 1993;88(4 Pt 1):1715–23. 27. Kupferwasser I, Mohr-Kahaly S, Stähr P, et al. Transthoracic three-dimensional echocardiographic volumetry of dis torted left ventricles using rotational scanning. J Am Soc Echocardiogr. 1997;10(8):840–52. 28. Nosir YF, Salustri A, Kasprzak JD, et al. Left ventricular ejection fraction in patients with normal and distorted left ventricular shape by three-dimensional echocardiographic methods: a comparison with radionuclide angiography. J Am Soc Echocardiogr. 1998;11(6):620–30. 29. Chukwu EO, Barasch E, Mihalatos DG, et al. Relative importance of errors in left ventricular quantitation by two-dimensional echocardiography: insights from threedimensional echocardiography and cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2008;21(9): 990–7.

1730


30. Gutiérrez-Chico JL, Zamorano JL, Pérez de Isla L, et al. Comparison of left ventricular volumes and ejection fractions measured by three-dimensional echocardiography versus by two-dimensional echocardiography and cardiac magnetic resonance in patients with various cardio myopathies. Am J Cardiol. 2005;95(6):809–13. 31. Corsi C, Lamberti C, Catalano O, et al. Improved quanti fication of left ventricular volumes and mass based on endocardial and epicardial surface detection from cardiac MR images using level set models. J Cardiovasc Magn Reson. 2005;7:595–602. 32. Mor-Avi V, Jenkins C, Kuhl HP, et al. Real-time 3D echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error. J Am Coll Cardiol Imaging. 2008;1:413–23. 33. Mor-Avi V, Sugeng L, Weinert L, et al. Fast measurement of left ventricular mass with real-time three-dimensional echocardiography: comparison with magnetic resonance imaging. Circulation. 2004;110(13):1814–18. 34. Soliman OI, Krenning BJ, Geleijnse ML, et al. Quantification of left ventricular volumes and function in patients with cardiomyopathies by real-time three-dimensional echocardiography: a head-to-head comparison between two different semiautomated endocardial border detection algorithms. J Am Soc Echocardiogr. 2007;20(9):1042–9. 35. Yao GH, Li F, Zhang C, et al. How many planes are required to get an accurate and timesaving measurement of left ventricular volume and function by real-time three-dimensional echocardiography in acute myocardial infarction? Ultrasound Med Biol. 2007;33(10):1572–8. 36. van den Bosch AE, Robbers-Visser D, Krenning BJ, et al. Real-time transthoracic three-dimensional echocardi o graphic assessment of left ventricular volume and ejection fraction in congenital heart disease. J Am Soc Echocardiogr. 2006;19:1–6. 37. Jenkins C, Chan J, Hanekom L, et al. Accuracy and feasibility of online 3-dimensional echocardiography for measurement of left ventricular parameters. J Am Soc Echocardiogr. 2006;19(9):1119–28. 38. Pouleur AC, le Polain de Waroux JB, Pasquet A, et al. Assessment of left ventricular mass and volumes by three-dimensional echocardiography in patients with or without wall motion abnormalities: comparison against cine magnetic resonance imaging. Heart. 2008;94(8): 1050–7. 39. Shimada YJ, Shiota T. A meta-analysis and investigation for the source of bias of left ventricular volumes and function by three-dimensional echocardiography in comparison with magnetic resonance imaging. Am J Cardiol. 2011;107(1):126–38. 40. Shimada YJ, Shiota T. Meta-analysis of accuracy of left ventricular mass measurement by three-dimensional echocardiography. Am J Cardiol. 2012 Apr 26. [Epub ahead of print].

41. Jiang L, Handschumacher MD, Hibberd MG, et al. Three-dimensional echocardiographic reconstruction of right ventricular volume: in vitro comparison with two-dimensional methods. J Am Soc Echocardiogr. 1994;7(2):150–8. 42. Jiang L, Siu SC, Handschumacher MD, et al. Threedimensional echocardiography. In vivo validation for right ventricular volume and function. Circulation. 1994;89(5):2342–50. 43. Shiota T, Jones M, Chikada M, et al. Real-time threedimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload. Circulation. 1998;97(19):1897–900. 44. Ota T, Fleishman CE, Strub M, et al. Real-time, threedimensional echocardiography: feasibility of dynamic right ventricular volume measurement with saline contrast. Am Heart J. 1999;137(5):958–66. 45. Chen G, Sun K, Huang G. In vitro validation of right ventricular volume and mass measurement by real-time three-dimensional echocardiography. Echocardiography. 2006;23(5):395–9. 46. Hoch M, Vasilyev NV, Soriano B, Gauvreau K, Marx GR. Variables influencing the accuracy of right ventricular volume assessment by real-time 3-dimensional echocardiography: an in vitro validation study. J Am Soc Echocardiogr. 2007;20(5):456–61. 47. Liu YN, Deng YB, Liu BB, et al. Rapid and accurate quanti fication of right ventricular volume and stroke volume by real-time 3-dimensional triplane echocardiography. Clin Cardiol. 2008;31(8):378–82. 48. Kjaergaard J, Petersen CL, Kjaer A, et al. Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI. Eur J Echocardiogr. 2006;7(6):430–8. 49. Nesser HJ, Tkalec W, Patel AR, et al. Quantitation of right ventricular volumes and ejection fraction by threedimensional echocardiography in patients: comparison with magnetic resonance imaging and radionuclide ventriculography. Echocardiography. 2006;23(8):666–80. 50. Gopal AS, Chukwu EO, Iwuchukwu CJ, et al. Normal values of right ventricular size and function by real-time 3-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20(5):445–55. 51. Jenkins C, Chan J, Bricknell K, et al. Reproducibility of right ventricular volumes and ejection fraction using real-time three-dimensional echo cardiography: comparison with cardiac MRI. Chest. 2007;131(6):1844–51. 52. Sugeng L, Mor-Avi V, Weinert L, et al. Multimodality comparison of quantitative volumetric analysis of the right ventricle. JACC Cardiovasc Imaging. 2010;3(1):10–18. 53. Leibundgut G, Rohner A, Grize L, et al. Dynamic assessment of right ventricular volumes and function by real-time three-dimensional echocardiography: a comparison study with magnetic resonance imaging in 100 adult patients. J Am Soc Echocardiogr. 2010;23(2):116–26.


54. Grewal J, Majdalany D, Syed I, et al. Three-dimensional echocardiographic assessment of right ventricular volume and function in adult patients with congenital heart disease: comparison with magnetic resonance imaging. J Am Soc Echocardiogr. 2010;23(2):127–33. 55. Grapsa J, O’Regan DP, Pavlopoulos H, et al. Right ventricular remodelling in pulmonary arterial hypertension with three-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. Eur J Echocardiogr. 2010;11(1):64–73. 56. Grison A, Maschietto N, Reffo E, et al. Three-dimensional echocardiographic evaluation of right ventricular volume and function in pediatric patients: validation of the technique. J Am Soc Echocardiogr. 2007;20(8):921–9. 57. Khoo NS, Young A, Occleshaw C, et al. Assessments of right ventricular volume and function using three-dimensional echocardiography in older children and adults with congenital heart disease: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2009;22(11):1279–88. 58. van der Hulst AE, Roest AA, Holman ER, et al. Real-time three-dimensional echocardiography: segmental analysis of the right ventricle in patients with repaired tetralogy of Fallot. J Am Soc Echocardiogr. 2011;24(11):1183–90. 59. van der Zwaan HB, Geleijnse ML, McGhie JS, et al. Right ventricular quantification in clinical practice: twodimensional vs. three-dimensional echocardiography compared with cardiac magnetic resonance imaging. Eur J Echocardiogr. 2011;12(9):656–64. 60. Shimada YJ, Shiota M, Siegel RJ, et al. Accuracy of right ventricular volumes and function determined by threedimensional echocardiography in comparison with magnetic resonance imaging: a meta-analysis study. J Am Soc Echocardiogr. 2010;23(9):943–53. 61. Altmann K, Shen Z, Boxt LM, et al. Comparison of threedimensional echocardiographic assessment of volume, mass, and function in children with functionally single left ventricles with two-dimensional echocardiography and magnetic resonance imaging. Am J Cardiol. 1997; 80(8):1060–5. 62. Soriano BD, Hoch M, Ithuralde A, et al. Matrix-array 3-dimensional echocardiographic assessment of volumes, mass, and ejection fraction in young pediatric patients with a functional single ventricle: a comparison study with cardiac magnetic resonance. Circulation. 2008;117(14):1842–8. 63. Kobayashi D, Patel SR, Mattoo TK, et al. The impact of change in volume and left-ventricular hypertrophy on leftventricular mechanical dyssynchrony in children with endstage renal disease. Pediatr Cardiol. 2012 Mar 23. [Epub ahead of print]. 64. Veeram Reddy SR, Du W, Zilberman MV. Left ventricular mechanical synchrony and global systolic function in pediatric patients late after ventricular septal defect patch closure: a three-dimensional echocardiographic study. Congenit Heart Dis. 2009;4(6):454–8. 65. Bacha EA, Zimmerman FJ, Mor-Avi V, et al. Ventricular resynchronization by multisite pacing improves myocardial

1731

performance in the postoperative single-ventricle patient. Ann Thorac Surg. 2004;78(5):1678–83. 66. Dragulescu A, Mertens LL. Developments in echocar diographic techniques for the evaluation of ventricular function in children. Arch Cardiovasc Dis. 2010;103 (11-12):603–14. 67. Pacileo G, Di Salvo G, Limongelli G, et al. Echocardiography in congenital heart disease: usefulness, limits and new techniques. J Cardiovasc Med (Hagerstown). 2007;8(1): 17–22. 68. Gorscan J III, Strum DP, Mandarino WA, et al. Quanti tative assessment of alterations in regional left ventricular contractility with color-coded tissue Doppler echocar diography. Circulation. 1997;95:2423–33. 69. Eidem BW, McMahon CJ, Cohen RR, et al. Impact of cardiac growth on Doppler tissue imaging velocities: a study in healthy children. J Am Soc Echocardiogr. 2004;17(3): 212–21. 70. Korinek J, Wang J, Sengupta PP, et al. Two-dimensional strain–a Doppler-independent ultrasound method for quantitation of regional deformation: validation in vitro and in vivo. J Am Soc Echocardiogr. 2005;18(12):1247–53. 71. Amundsen BH, Helle-Valle T, Edvardsen T, et al. Noninvasive myocardial strain measurement by speckle tracking echocardiography: validation against sonomicrometry and tagged magnetic resonance imaging. J Am Coll Cardiol. 2006;47(4):789–93. 72. Young AA, Axel L, Dougherty L, et al. Validation of tagging with MR imaging to estimate material deformation. Radiology. 1993;188(1):101–8. 73. Amundsen BH, Helle-Valle T, Edvardsen T, et al. Noninvasive myocardial strain measurement by speckle tracking echocardiography: validation against sonomicrometry and tagged magnetic resonance imaging. J Am Coll Cardiol. 2006;47(4):789–93. 74. Moore CC, Lugo-Olivieri CH, McVeigh ER, et al. Threedimensional systolic strain patterns in the normal human left ventricle: characterization with tagged MR imaging. Radiology. 2000;214(2):453–66. 75. Marcus KA, Mavinkurve-Groothuis AM, Barends M, et al. Referen\nics using speckle tracking echocardi ography: fundamentals and clinical applications. J Am Soc Echocardiogr. 2010;23(4):351–69; quiz 453. 78. Bansal M, Cho GY, Chan J, et al. Feasibility and accuracy of different techniques of two-dimensional speckle based strain and validation with harmonic phase magnetic resonance imaging. J Am Soc Echocardiogr. 2008;21(12): 1318–25. 79. D’hooge J, Konofagou E, Jamal F, et al. Two-dimensional ultrasonic strain rate measurement of the human heart in vivo. IEEE Trans Ultrason Ferroelectr Freq Control. 2002;49(2):281–6. 80. Perez de Isla L, Balcones DV, Fernandez-Golfin C, et al. Three-dimensional-wall motion tracking: a new and faster tool for myocardial strain assessment: comparison with two dimensional wall motion tracking. J Am Soc Echocardiogr. 2009; 22:325–30.

1732


81. Gayat E, Ahmad H, Weinert L, et al. Reproducibility and inter-vendor variability of left ventricular deformation measurements by three-dimensional speckle-tracking echocardiography. J Am Soc Echocardiogr. 2011;24(8): 878–85. 82. Nesser HJ, Mor-Avi V, Gorissen W, et al. Quantification of left ventricular volumes using three-dimensional echocar diographic speckle tracking: comparison with MRI. Eur Heart J. 2009;30(13):1565–73. 83. Maffessanti F, Nesser HJ, Weinert L, et al. Quantitative evaluation of regional left ventricular function using three-dimensional speckle tracking echocardiography in patients with and without heart disease. Am J Cardiol. 2009;104(12):1755–62. 84. Bussadori C, Moreo A, Di Donato M, et al. A new 2D-based method for myocardial velocity strain and strain rate quantification in a normal adult and paediatric population: assessment of reference values. Cardiovasc Ultrasound. 2009;7:8. 85. Zhang L, Gao J, Xie M, et al. Left ventricular threedimensional global systolic strain by real-time threedimensional speckle-tracking in children: feasibility, reproducibility, maturational changes, and normal ranges. J Am Soc Echocardiogr. 2013; 26(8):853-9. 86. Saltijeral A, Isla LP, Pérez-Rodríguez O, et al. Early myocardial deformation changes associated to isolated obesity: a study based on 3D-wall motion tracking analysis. Obesity (Silver Spring). 2011;19(11):2268–73. 87. Zhang L, Xie M, Balluz R, Ge S. Real time three-dimensional echocardiography for evaluation of congenital heart defects: state of the art. Echocardiography. 2012;29(2): 232–41. 88. Caiani EG, Corsi C, Zamorano J, et al. Improved semiautomated quantification of left ventricular volumes and ejection fraction using 3-dimensional echocar diog raphy with a full matrix-array transducer: comparison with magnetic resonance imaging. J Am Soc Echocardiogr. 2005;18(8):779–88.

89. Jacobs LD, Salgo IS, Goonewardena S, et al. Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data. Eur Heart J. 2006;27(4):460–8. 90. Nikitin NP, Constantin C, Loh PH, et al. New generation 3-dimensional echocardiography for left ventricular volumetric and functional measurements: comparison with cardiac magnetic resonance. Eur J Echocardiogr. 2006;7(5):365–72. 91. Krenning BJ, Kirschbaum SW, Soliman OI, et al. Comparison of contrast agent-enhanced versus non-contrast agentenhanced real-time three-dimensional echocardiography for analysis of left ventricular systolic function. Am J Cardiol. 2007;100(9):1485–9. 92. Qi X, Cogar B, Hsiung MC, et al. Live/real time threedimensional transthoracic echocardiographic assessment of left ventricular volumes, ejection fraction, and mass compared with magnetic resonance imaging. Echocar diography. 2007;24(2):166–73. 93. Macron L, Lim P, Bensaid A, et al. Single-beat versus multibeat real-time 3D echocardiography for assessing left ventricular volumes and ejection fraction: a comparison study with cardiac magnetic resonance. Circ Cardiovasc Imaging. 2010;3(4):450–5. 94. Chang SA, Lee SC, Kim EY, et al. Feasibility of singlebeat full-volume capture real-time three-dimensional echocardiography and auto-contouring algorithm for quantification of left ventricular volume: validation with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2011;24(8):853–9. 95. Iriart X, Montaudon M, Lafitte S, et al. Right ventricle three-dimensional echography in corrected tetralogy of Fallot: accuracy and variability. Eur J Echocardiogr. 2009;10(6):784–92. 96. Balluz R, Liu L, Zhou X, et al. Real time three-dimensional echocardiography for quantification of ventricular volumes, mass, and function in children with congenital and acquired hear diseases. Nanda NC (Editor). Echocardiography. 2013;30(4):472–82.

CHAPTER 74 Three-Dimensional Echocardiography in Congenital Heart Disease Steven Bleich, Gerald R Marx, Navin C Nanda, Fadi G Hage

Snapshot  Shunt Lesions/Septal Defects  Common Atrium  Aortopulmonary Window  Patent Ductus Arteriosus (PDA)  Conotruncal Anomalies  Ouƞlow Tract ObstrucƟon

INTRODUCTION Congenital heart disease (CHD) includes an extensive group of diagnoses affecting both pediatric and adult patients. The complexity of CHD has motivated cardiologists to better understand each individual defect in order to maximize management of these patients and improve treatment options. Two-dimensional (2D) echocardiography has been the gold standard imaging modality used because of its convenience, low cost, and lack of harmful side effects as compared to magnetic resonance imaging (MRI) and multidetector computed tomography (CT).1,2 However, identifying and understanding CHD often requires a real life, three-dimensional (3D) image of the defect.3–5 With 2D echocardiography, the reader often expends effort to mentally reconstruct the heart and great vessels in three dimensions, sometimes, preventing visualization of relevant details. The emergence of 3D echocardiography (3DE) provides a more comprehensive view of the cardiac anatomy which offers incremental value in the diagnosis of CHD. 3DE has gained popularity in the field of CHD because it can portray a dynamic and realistic picture of the

 AorƟc Arch Anomalies  Atrial and Atrioventricular Valve AbnormaliƟes  Other AbnormaliƟes  Double Outlet Right Ventricle  Sinus of Valsalva Aneurysm

structural defect and nearby cardiac structures.6 Views previously unobtainable by 2D echocardiography are captured readily by 3D imaging offering further insight regarding morphology, location, specific dimensions, and dynamic changes of specific heart structures during the cardiac cycle.4 3DE enhances cardiologists’ understanding of CHD by providing unique and valuable data that is useful in determining the appropriate treatment option for each specific defect.5

SHUNT LESIONS/SEPTAL DEFECTS Longstanding congenital heart defects causing elevated pulmonary artery pressure can cause significant strain on the right ventricle, ultimately resulting in right ventricular remodeling and dysfunction. The ability to measure right ventricular size and function can guide medical and surgical management before deterioration in right ventricular function. For example, in patients following surgical repair of Tetralogy of Fallot (ToF), follow-up imaging to detect ventricular dysfunction and remodeling can help to determine the appropriate time for placement of a competent pulmonary valve to avoid further

1734


complications such as right ventricular failure, arrhythmia, and sudden cardiac death.7 Unfortunately, based on the intricate shape of the right ventricle, measurement of its size and function pose a challenge to traditional 2D imaging.7 Cardiac MRI has previously been utilized to measure this data, but due to its cost, extensive time necessary to obtain and interpret images, and restrictive accessibility, its use is limited.7,8 3D-transthoracic echocardiography (TTE) has considerable advantage over 2D TTE because of its ability to accurately assess volume and function of the right ventricle based on the unique views it provides.9 Strong correlations between 3DE and cardiac MRI for the quantitative analysis of the right ventricle have been reported, but limitations including underestimation of right ventricular volume and the visualization of the entire right ventricle in patients with an enlarged right ventricle in a single imaging window must be recognized.7 With regard to 3DE, the American Society of Echocardiography (ASE) suggests that capturing higher quality images may facilitate increased utilization of this modality.10 Equally important in CHD is the assessment of single ventricular size and function. Studies comparing 3D echocardiographic measurements of single ventricle volumes, mass, and ejection fraction compare favorably to MRI in young infants.11 The ability to measure left ventricular volumes in patients with borderline left hearts being considered for either single ventricle palliative surgeries or biventricular repair is also significant. Often the ventricles are spherical and thus 2D imaging relies on mathematical assumptions that often do not apply. Threedimensional imaging has been shown to again provide measurements of left ventricular size and function in small young infants as compared to MRI.12

Atrial Septal Defects (ASDs) Atrial septal defects represent 7–10% of all congenital heart defects, often diagnosed incidentally in asymptomatic adults.13,14 An ASD can consist of one or multiple defects and understanding the extent of the defects is key in planning for the appropriate corrective procedure (Figs 74.1A to D). This is especially germane when considering defects for catheterization closure. There are several different types of ASDs depending on their location in the atrial septum and they are discussed below.

Secundum ASD Secundum ASDs and patent foramen ovale (PFO) occupy the middle portion of the atrial septum. Although 2D echocardiography has historically been the imaging modality of choice in diagnosing these ASDs, images obtained via this method can lack optimal viewing of the defect and therefore distort the measurements obtained.15 In the setting of multiple fenestrations such as the Swiss cheese pattern or multiple hole pattern, the limitations of 2D TTE are even more obvious. The key to any successful echocardiographic image relies on a clear imaging window with the patient in a position that provides the best view for the reader. 3D TTE performed using the apical, para-apical, right parasternal and subcostal views provides adequate en face visualization of the defect in most patients (Figs 74.2 and 74.3). The interatrial septum is often best observed in the right parasternal view with the patient in the right lateral decubitus position.15 Information regarding exact dimensions and location of an ASD along with relative surrounding cardiac anatomy and rim size can be obtained more easily by 3D TTE than 2D transesophageal echocardiography (TEE).15,16 With the advent of real time 3D TTE, a PFO can be visualized as well as the motion of the valve covering it (Figs 74.4 and 74.5).17 Recognizing the development of worsening dyspnea and hypoxia with change in position from the supine to sitting position suggests the possibility of platypnea-orthodeoxia syndrome. 3D TEE has been used to document an open PFO with shunting of blood in the sitting position and closed PFO in the supine position (Figs 74.6 and 74.7).18 One study done by Morgan et al. compared the results obtained by 2D TEE to 3D TTE with respect to maximum defect diameter, area and circumference of an ASD.19 Data obtained from these two modalities were not statistically different, however, 3D TTE compared to 2D TEE provided clinically significantly information. 3D was able to recognize appropriate candidates for percutaneous closure of an ASD while eliminating the need for more invasive imaging with TEE. Repair of ASDs have traditionally been performed with surgery, however, recent evidence recommends the use of more percutaneous closure devices. The decision to proceed with surgery versus percutaneous approach depends on the location of the ASD, its shape and size, and the surrounding tissue.4,15 In order to proceed with percutaneous repair, the cutoff with regard to rim size has

Chapter 74: Three-Dimensional Echocardiography in Congenital Heart Disease

A

B

C

D

1735

Figs 74.1A to D: Live three-dimensional right parasternal transthoracic echocardiographic examination of atrial septum and superior and inferior vena cavae. (A and B) Color Doppler examination in another patient showing four (numbered 1 through 4) separate secundum defects at different levels of the atrial septum; (C and D) Two of these defects are viewed en face. In this 25-year-old female, four atrial septal defects at different levels of the atrial septum could be demonstrated by sequential cropping of the three-dimensional dataset. Only two of these defects could be visualized by two-dimensional transthoracic echocardiography. (LA: Left atrium; RA: Right atrium). (Movie clip 74.1). Source: Reproduced with permission from Patel V, Nanda NC, Upendram S, et al. Live three-dimensional right parasternal and supraclavicular transthoracic echocardiographic examination. Echocardiography. 2005;22:349–60.

been set at 5 mm. Obtaining a comprehensive view of the defect and nearby cardiac structures is feasible with 3D TTE compared to 2D echocardiography, which helps in determining the appropriate therapeutic intervention.20 In patients with secundum ASD, the most common type of ASD encountered in clinical practice, 3D TTE can view the defect and surrounding rims of tissue which is valuable when planning a transcatheter approach.15,21 The ability of 3D TTE to calculate accurate measurements of the defect size has been validated by recording similar measurements during surgical and percutaneous repair.15,22 Knowing the exact dimensions of the defect is

important when selecting the size of the occluder device which can prevent postprocedure complications. Placing of an inappropriately sized occluder device can lead to persistence of the shunt, invasion of nearby cardiac anatomy, breakdown of the device, device embolization and even perforation of the heart.23 Understanding the serious nature of these complications substantiates the need to precisely document the defect, its size, and all relevant cardiac anatomy. Furthermore, in the setting of an above mentioned complication, 3DE has been life saving in visualizing the abnormality and allowing immediate repair.24 Color Doppler 3D TTE can identify a small residual

1736


A

B

Figs 74.2A and B: Live three-dimensional transthoracic echocardiographic (3D TTE) assessment of atrial septal defect. Arrowhead points to a large secundum atrial septal defect visualized from both right (RA, A) and left atrial (LA, B) aspects. Note the large rim of tissue surrounding the defect. (AS: Atrial septum). Movie clip 74.2, Part 1 shows en face viewing of a small atrial septal defect from both the left and right atrial aspects. There is an ample rim of tissue surrounding the defect. Movie clip 74.2, Part 2 from another adult patient with a secundum atrial septal defect. Regular and QLab (Philips Medical Systems, Andover, MA) cropping of the 3D data set views the large defect en face (two arrowheads). Reasonable amount of atrial septal tissue surrounds the defect. The defect measures 3.2 × 3.1 cm, area 9.2 cm2. Movie clip 74.2, Part 3 from another patient with a secundum atrial septal defect. The two-dimensional study shows a large defect (arrowhead) in the apical 4-chamber and subcostal views. Regular and QLab croppings view the large defect en face (two arrowheads/arrows). Although the defect is similar in size to the previous patient, there is hardly any rim of the tissue adjacent to the aorta making it hazardous to close it in the catheterization laboratory. Movie clip 74.2, Parts 4 and 5. In this large patient, a secundum defect in the atrial septum (AS) was suspected during subcostal examination but a definitive diagnosis could not be made. When the images were acquired using a three-dimensional transducer and cropped, the defect (arrow) was clearly visualized with left and right shunting. (LA: Left atrium; RA: Right atrium). [Movie clip 74.2, (Parts 1 to 5)]. Source: Reproduced with permission from Mehmood F, Vengala S, Nanda NC, et al. Usefulness of live three-dimensional transthoracic echocardiography in the characterization of atrial septal defects in adults. Echocardiography J. 2004;21:707–13.

Fig. 74.3: Three-dimensional image of atrial septal defect: en face view of the atrial septum, from the right atrium. Accurate description of the surrounding rims and their measurements provided by TomTec software, in the preoperative assessment of this young patient. (AV: Atrioventricular; IVC: Inferior vena cava; SVC: Superior vena cava; RV: Right ventricle; RA: Right atrium). Source: Reproduced with permission from De Castro S, Caselli S, Papetti F, et al. Feasibility and clinical impact of live threedimensional echocardiography in the management of congenital heart disease. Echocardiography. 2006;23:553–61.

shunt after the placement of an ASD occluder device that often occurs and usually resolves over time.25 3D TTE is useful in evaluating the morphology and effectiveness of percutaneous closure devices used for closure of an ASD and PFO (Figs 74.8 to 74.10).

Current ASE guidelines advocate for the utilization of 2D TEE during a percutaneous closure repair because of precise measurements of the ASD’s maximum dimension and bordering septal rims, however, its limitations must be understood.24 The success of 2D TEE relies on the


A

1737

B

Figs 74.4A and B: Live three-dimensional transthoracic echocardiography assessment of patent foramen ovale (PFO). (A and B) Arrow shows the PFO while the arrowheads point to contrast signals moving through the defect into the left atrium (LA) following an intravenous agitated saline injection. 3D TTE, three-dimensional transthoracic echocardiographic; (LV: Left ventricle). Source: Reproduced with permission from Mehmood F, Vengala S, Nanda NC et al. Usefulness of live three dimensional transthoracic echocardiography in the characterization of atrial septal defects in adults. Echocardiography J. 2004;21:707–13.

A

B

C

D

Figs 74.5A to D

1738


E

Figs 74.5A to E: Real time/three-dimensional transthoracic echocardiographic visualization of the valve of foramen ovale. Right parasternal approach. (A) Arrowhead points to the atrial septum; (B and C) En face view of the atrial septum from the left atrial (LA) side shows the valve of foramen of ovale in the closed (B) and open (C) positions. In the closed position it completely covers the foramen ovale; (D) Arrowhead points to a mobile flap of tissue at the junction of superior vena cava (SVC) and right atrium (RA) representing a remnant of right-sided sinus venosus valve; (E) Arrowhead shows the Eustachian valve. (IVC: Inferior vena cava). [Movie clip 74.5, (Parts 1 to 8)]. Source: Reproduced with permission from Panwar SR, Perrien JL, Nanda NC, Singh A, Rajdev S. Real time/three-dimensional transthoracic echocardiographic visualization of the valve of foramen ovale. Echocardiography. 2007;24:1105–7.

Fig. 74.6: Transesophageal echocardiogram in the supine position. Echogram taken in the supine position showing the foramen ovale is closed (right figure), and no apparent right-to-left shunt by Doppler color flow (left figure). (LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Sasaki T, Miyasaka Y, Suwa Y, et al. Real time three-dimensional transesophageal echocardiographic images of platypnea-orthodeoxia due to patent foramen ovale. Echocardiography. 2013;30:E116–17.

Fig. 74.7: Transesophageal echocardiogram in the sitting position. Echogram taken in the sitting position showing the foramen ovale is wide open (right figure), with a massive right-to-left shunt across the patent foramen ovale by Doppler color flow (left figure). (LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Sasaki T, Miyasaka Y, Suwa Y, et al. Real time three-dimensional transesophageal echocardiographic images of platypnea-orthodeoxia due to patent foramen ovale. Echocardiography. 2013;30:E116–17.

observer’s ability to obtain unlimited angles and views of the ASD and mentally recreate these images into 3D. Undoubtedly, this task is difficult and may preclude a comprehensive evaluation of the defect before, during and after the procedure. 3D TEE offers a distinct en face view of the defect compared to 2D TEE, providing accurate measurements as well as confirmation of device placement in its appropriate position. 3D TEE is effective in measuring the defect size, rim size, left atrial (LA) and right atrial (RA) occluder disc

dimensions, and distance between the LA and the aorta in patients with secundum ASD determined to be appropriate candidates for a percutaneous closure procedure.24 There have been reports of encroachment of the LA occluder disc on the aorta observed by 3D TEE, putting patients at risk of aortic erosion and even cardiac tamponade (Fig. 74.11). Insufficient rim size and placement of a wrong sized occluder device are likely contributing factors in causing aortic erosions. Bhaya et al. found a correlation between the maximum dimension of the ASD, the length of the LA


A

B

C

D

E

F

1739

Figs 74.8A to F: Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect. (A) Arrow points to the waist of the atrial septal defect (ASD) transcatheter closure device; (B and C) Shows the device viewed from the top (B) and obliquely (C). Note that the left atrial disc (# 1) is larger than the right atrial disc (# 2); (D) Arrowhead points to the stainless steel screw thread located in the center of the right atrial disc viewed enface; (E) Arrow points to the small residual shunt seen one day after the device was positioned; (F) Amplatzer device used for transcatheter closure of ASD. Arrowhead points to the metallic cap and the arrow points to the waist of the device. (LA: Left atrium; LV: Left ventricle; MC: Metallic cap; NW: Nitinol winding; RA: Right atrium; RV: Right ventricle; ST: Screw thread). Movie clip 74.8 shows 3D TTE examination of the atrial septal defect closure device 6 weeks after implantation. The device is well seated. (Movie clip 74.8). Source: Reproduced with permission from Sinha A, Nanda NC, Misra V, et al. Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale. Echocardiography. 2004;21:749–53.

disc, the waist size of the device, and the distance between the LA disc and the aorta.24 3D TEE measurements of LA and RA disc lengths have been nearly identical to the manufacturer’s assigned size, validating its calculations. 3D TEE is capable of not only selecting proper patients for the percutaneous procedure, but also identifying patients at higher risk of complications prompting more regular follow-up. Device embolization is a serious complication of percutaneous repair that can be minimized by accurate measurements of the ASD and placement of an appropriate sized occluder device. Wei et al. described an unfortunate

case of a patient with a complex Swiss cheese type secundum ASD resulting in device embolization to the left atrium and then right iliac artery (Figs 74.12A to G).26 Initial imaging with 2D TTE was inaccurate compared to follow-up imaging with 3D TTE in evaluating the complexity of the ASD based on the absence of en face views of the entire atrial septum. When defects include multiple fenestrations, the risk of complications from a percutaneous repair increases tremendously and alternative treatment options must be considered.26 3D TTE can help to select good candidates for percutaneous repair of ASD and to inform both patients and physicians of the risk of possible complications.

1740


Fig. 74.9: Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of patent foramen ovale (PFO). Represent the left atrial and right atrial discs of the transcatheter device used to close the PFO. (LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Sinha A, Nanda NC, Misra V, et al. Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale. Echocardiography. 2004;21:749–53.

B

C

D

E

F

G

Figs 74.10A to G: Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect. In vitro studies. (A and B) Arrowhead shows the stainless steel screw thread. # 1 and # 2 represent the left atrial and right atrial discs seen enface (A) and from the side (B); (C) Arrowhead points to the metallic cap seen in the middle of the left atrial disc. This is where the nitinol windings come together; (D to G) Real time, 2-dimensional transthoracic echocardiography in embolization of atrial septal defect occlusion device; (D) Arrowhead points to the device located at the bifurcation of the main pulmonary artery; (E) Color Doppler-guided continuous-wave Doppler interrogation demonstrates absence of significant obstruction. Peak velocity is only 1.47 m/s; (F and G) Live/real time, three-dimensional transthoracic echocardiography in embolization of atrial septal defect occlusion device; (F) Arrowhead points to the device located at the bifurcation of the main pulmonary artery; (G) Atrial septal defect viewed en face from the right atrial side (dotted line). (AO: Aorta; LPA: Left pulmonary artery; RPA: Right pulmonary artery). Source: Figs 10A to C Reproduced with permission from Sinha A, Nanda NC, Misra V, et al. Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale. Echocardiography. 2004;21:749–53. Source: Figs 10D to G Reproduced with permission from Dod HS, Reddy VK, Bhardwaj R, et al. Embolization of atrial septal occluder device to the pulmonary artery: A rare complication and usefulness of live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2009;26:6.

A


1741

Fig. 74.11: Multiplanar rendering mode: Upper panels. Top arrowheads point to the left atrial disc, lower arrowheads to the right atrial disc. D1 represents the measurement of the radius of the left atrial disc from the middle of the central marker band to the outer edge of the disc. D2 represents the measurement of the radius of the right atrial disc from the middle of the end screw to the outer edge of the disc. The arrow in the top right panel points to the area of contact of the left atrial disc with the aorta (AO) Lower panels. Arrowhead in the right lower panel points to the left atrial disc covering the atrial septal defect. Movie clip 74.11 shows the left atrial disc in contact with the aorta throughout the cardiac cycle. Source: Reproduced with permission from Bhaya M, Mutluer FO, Mahan III EF, et al. Incremental utility of live/real time threedimensional transesophageal echocardiography in percutaneous closure of atrial septal defects. Echocardiography. 2013;30: 345–53.

A

B

C

D

Figs 74.12A to D

1742


E

G

Sinus Venosus ASD Sinus venosus ASD (SVASD) represents ~4% to 11% of ASDs.24 Some experts believe that a sinus venosus defect is not a true ASD, but rather the failure of interposition of the wall between the superior vena cava and the right upper pulmonary veins of superior sinus venosus defects or lack of the wall separating the right lower pulmonary veins from the back wall of the right atrium in patients with inferior sinus venosus defects. Hence, the veins connect normally but drain abnormally due to this lack of interposing “walls” and therefore, a sinus venosus defect is often not characterized as simply a hole in the wall between the atria. The capabilities of 3DE have been shown to be effective in assessing a sinus venosus defect, 3D TEE reconstruction images confidently visualize the defect in

F Figs 74.12A to G: Live/real time, three-dimensional transesophageal echocardiographic assessment of device embolization during percutaneous atrial septal defect closure. (A) The arrowheads point to multiple secundum atrial septal defects (ASD, “swiss cheese” appearance) viewed en face from the left atrium (LA); (B) Color Doppler assessment showing flow signals within the defects viewed en face (left panel). QLAB examination (right panel) showing four defects numbered 1, 2, 3, and 4; (C) QLAB examination demonstrating en face view of one of the defects (1) using Color Doppler. In the upper left panel the cropping plane is positioned exactly parallel to the defect which resulted in en face viewing of the defect in the lower left panel. Subsequently the area was measured by planimetry; (D) Demonstrates the first ASD closure device (D1) in position (viewed from left atrium and anatomically correct). Arrowhead shows a large residual defect viewed en face. The arrow points to the device placement catheter; (E) Shows the second ASD closure device (D2) in position, partially overlapping D1 (viewed from left atrium and anatomically correct). Arrowhead shows the presence of one of the two significant residual defects; (F) Shows embolization of one of the closure devices (D) to the LA; (G) Shows the device (D) in the proximal descending thoracic aorta (DA) after percutaneous manipulation from the iliac artery. 1 and 2 denote the right and the left atrial sides of the device, which are viewed en face in the left lower and the right upper panels. (MV: Mitral valve; RA: Right atrium). Source: Reproduced with permission from Wei J, Hsiung MC, Tsai SK, et al. Atrial septal occluder device embolization to an iliac artery: A case highlighting the utility of three-dimensional transesophageal echocardiography during percutaneous closure. Echocardiography. 2012;29:1128–31.

relation to the superior vena cava (SVC) and right superior pulmonary vein offering significant advantage over 2D TEE (Figs 74.13A to C).27 Both modalities are successful in sizing the defect comparatively to actual surgical measurements, but 3D TEE was also capable of calculating the area of the defect with the extra dimensions it obtained.


A

B

1743

C

Figs 74.13A to C: Multiplane transesophageal 3D reconstruction of sinus venosus ASD. (A) The arrowhead points to the large defect in the superior portion of the atrial septum. The arrow shows the right superior PV entering the SVC-atrial junction at the site of the defect. (B and C) Orthogonal views demonstrating the size of the defect (ASD), which measured 3.69 cm2 in area. The maximal dimension of the defect was 2.15 cm, which corresponded to the diameter of 2 cm measured at surgery. The top arrowhead in B points to the right superior PV, and the bottom arrowhead points to the defect. (ASD: Atrial septal defect; SVC: Superior vena cava; LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Nanda NC, Ansingkar K, Espinal M, et al. Transesophageal three-dimensional echo assessment of sinus venosus atrial septal defect. Echocardiography. 1999;16:835–7.

Unroofed Coronary Sinus

Ventricular Septal Defects

Unroofed coronary sinus is an uncommon type of ASD which involves a communication between the roof of the coronary sinus and the left atrium and is often diagnosed in combination with a persistent left superior vena cava.28 Unroofing of the coronary sinus can also occur intentionally with surgical repair when there is total anomalous return of the pulmonary veins to the coronary sinus.29 The diagnosis of unroofed coronary sinus can be difficult to ascertain with 2D imaging, and when very large can be mistaken for a primum ASD. Importantly, when an unroofed coronary sinus defect is associated with a left superior vena cava, right-to-left shunting can occur, leading to serious side effects such as a cerebral emboli or a brain abscess.28 An acquired unroofed coronary sinus was reported in an adult patient after there was breakdown of the surgical patch that was placed over the coronary sinus ostium to repair total anomalous pulmonary venous return (TAPVR) during infancy (Figs 74.14A to E).29 With its technological advanced cropping capabilities and the views captured from unique angles, 3D TTE clearly visualized the communication between the coronary sinus and the left atrium confirming the diagnosing suggested by coronary angiography. Furthermore, 3D color Doppler imaging confirmed the left-to-right shunting of blood from left atrium through the defect in the roof of the coronary sinus into the right atrium.

Ventricular septal defects (VSD) represent a commonly diagnosed congenital heart defect in the newborns. The defect is most often located within the muscular or perimembranous portion of the interventricular septum. The diagnosis of a VSD can be made by 2D echocardiography, however, the accuracy of its measurements are often inconsistent because of the typical oval shape of a VSD.30 As a result of its uneven contour, 2D views are unable to accurately quantify the true dimensions of the defect, often resulting in underestimation.4,30 The location, dimensions and shape of the VSD are more accurately assessed by live/real time 3D TTE (Figs 74.15A and B).22 With a more complex VSD, the capabilities of 3DE are even more apparent when compared to 2D echocardiography. 3D TTE presents an en face view of the defect to provide more reliable measurements of its area and circumference to better assist the cardiologist in planning for treatment (Figs 74.16A and B).31 Similar to ASDs, there has been some transition in the treatment of muscular, and to some extent perimembranous VSDs, from the traditional surgical approach to percutaneous repair because of reported decreased mortality rate and fewer complications compared to surgery.31 On the other hand, many medical centers and expert pediatric cardiologists prefer not to perform percutaneous closure of membranous VSDs because of high incidence of heart block, damage to

1744


A

B

C

D

E

Figs 74.14A to E: Real time/live three-dimensional transthoracic echocardiographic findings in coronary sinus atrial septal defect. (A and B) Arrowhead points to unroofed coronary sinus (CS) which resulted in left atrial (LA) to right atrial (RA) shunting; (C) Shows opening (arrow) of CS into RA; (D) Parasternal long-axis view. Arrowhead points to a defect in the roof of CS resulting in communication with LA; (E) Two-dimensional transthoracic echocardiography in the same patient. Arrowhead points to a questionable defect in lower portion of atrial septum. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). (Movie clip 74.14). Source: Reproduced with permission from Singh A, Nanda NC, Romp RL, Kirklin JK. Assessment of surgically unroofed coronary sinus by real time/live time three-dimensional transthoracic echocardiography. Echocardiography. 2007;24:74–6.


A

1745

B

Figs 74.15A and B: (A) The arrowhead points to a perimembraneous ventricular septal (VS) defect viewed en face; (B) Shows color Doppler flow signals in the defect. (LA: Left atrium; LVOT: Left ventricular outflow tract; MV: Mitral valve; RV: Right ventricle). [Movie clip 74.15, (Parts 1 to 4)]. Source: Reproduced with permission from Mehmood F, Miller AP, Nanda NC, et al. Usefulness of live/three-dimensional transthoracic echocardiography in the characterization of ventricular septal defects in adults. Echocardiography. 2006;23:421–7.

A

B

Figs 74.16A and B: (A and B) Ventriuclar septal defect. The arrow in A points to a large defect in the trabecular ventricular system visualized in the apical four-chamber view. The arrow in B shows the same defect viewed en face by cropping of the three-dimensional data set. Note the generous margins of the defect. Color Doppler examination shows flow signals moving through the defect. (Movie clip 74.16). Source: Reproduced with permission from Nanda NC, Hsiung MC, Miller AP, et al. Live/real time 3D echocardiography. Chichester, West Sussex: Wiley, Blackwell, 2010.

the aortic valve, and hemolysis. With the percutaneous procedure, obtaining precise dimensions of the defect and visualizing nearby cardiac structures becomes even more important. Compared to 2D TTE, 3D TTE provides a “surgeon’s view” of the cardiac anatomy to the

interventionalist prior to the start of the procedure which can be utilized in the preprocedural planning.30 The use of 3D TEE for comprehensive assessment of VSDs has become more accepted because of the unique angles and views obtained of the interventricular septum

1746


and the accurate data with regard to size and shape of the defect. 3D TTE can be used in clinical situations that previously relied on 3D TEE because of comparable information provided by both and can be performed in less invasive manner. Another advantage of 3D TTE compared to 2D echocardiography is its ability to more accurately depict the distance from the defect to the tricuspid valve, a very important measurement in preventing complications during repair of the defect.30 Identification of the exact location of the atrioventricular valves and the extent of the anatomical rim in relation to the VSD, plays a significant role in determining whether a patient would benefit more from a surgical or a percutaneous intervention (Figs 74.17 and 74.18). Fortunately, 3D TTE is capable of capturing such images clearly. The effectiveness of 3D TTE in measuring maximum dimension, circumference, and area of the VSD was validated with comparable surgical and intraoperative findings by 3D TEE.30 By visualizing the VSD en face with 3D TTE, an added dimension of depth is incorporated into the surgical decision making process.32

Atrioventricular Septal Defects Atrioventricular septal defect (AVSD) is a type of CHD that occurs as a result of incomplete fusion of the superior and inferior endocardial cushions. Absence of fusion of these structures during fetal development results in abnormal development of both the atrioventricular septum as well as the corresponding valves.33 There are three types of ASVDs: complete, partial, and intermediate. Complete ASVDs are distinguished by a large AVSD (primum ASD and inlet VSD) in combination with a single atrioventricular valve (Fig. 74.19A to G).33 Modified Rastelli

types A, B, and C are used to categorize complete ASVDs based on the superior bridging leaflet and its attachments to the crest of the ventricular septum and right ventricle.34 Partial ASVDs, on the other hand, have variable defects affecting the atrial septum, ventricular septum or both and is characterized by the presence of separate right and left atrioventricular valves (Fig. 74.20A to E). Recognizing the narrow and elongated left ventricular outflow tract (the so-called “goose neck” deformity seen on the angiogram) and the lack of wedging of the aorta between the mitral and tricuspid valves is diagnostic in patients with ASVD. These findings are presumed to be secondary to the displacement of the left ventricular outflow tract and aortic valve in the anterior and superior direction.33,34 Investigation of 3D TTE in patients with ASVDs noted obvious advantages over 2D TTE in measuring the size and magnitude of the defect and valves, as well as nearby cardiac structures.33 The ability of 3D TTE to provide an en face view of a complete ASVD and furthermore a clear delineation of the characteristic five leaflets in complete defects, sets this modality apart from the capabilities of 2D TTE (Figs 74.21A to D).34 In addition, 3D TTE can identify the superior bridging leaflet and its attachment which is responsible for categorizing ASVDs into modified Rastelli types.33,34 Singh et al. described a patient with a presumed diagnosis of Rastelli type C ASVD based on imaging with 2D TTE, however, follow-up imaging with 3D TTE demonstrated that the defect was actually a Rastelli type A ASVD.33 Similarly, 2D TTE provided visualization of a right and left atrioventricular valve annuli, suggesting a partial ASVD, but an en face view of 3D TTE also identified features of a complete ASVD confirming the

Fig. 74.17: Shows the relationship and the distances of pulmonary valve and tricuspid valve from the ventricular septal defect. (PV: Pulmonary valve; TV: Tricuspid valve; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Chen FL, Hsiung NC, Nanda NC, Hsieh KS, Chou MC. Real time 3-dimensional echocardiography in assessing ventricular septal defects: An echocardiographic-surgical correlative study. Echocardiography. 2006;23:562–8.


A

B

C

E

F

G

1747

D

Figs 74.18A to G: Perimembranous ventricular septal defect (inlet) (arrow). (A) Real time 3D echocardiography (RT3DE) volume-rendered image of the right ventricle (RV) displaying the right aspect of the ventricular septal defect. The location of the defect in relation to the tricuspid valve (TV) is shown; (B) Surgical view of VSD from the right aspect; (C) RT3DE volume-rendered image of the left ventricle (LV) displaying the left aspect of the VSD. The location of the defect in relation to the left ventricular outflow tract (LVOT) is shown; (D) 2DE parasternal long-axis views showed the VSD in relation to aortic valve and right ventricle; (E to G) Live three-dimensional transthoracic echocardiography in a patient with tetralogy of Fallot; (E) Note the wide aortic root (AO) and narrow pulmonary artery (PA); (F) The AO overrides the interventricular septum (IVS); (G) Four-chamber view. The ventricular septal defect (VSD) is located at the crux. (AO: ZAorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle); Source: Figures 18A to D reproduced with permission from Chen FL, Hsiung NC, Nanda NC, Hsieh KS, Chou MC. Real time 3-dimensional echocardiography in assessing ventricular septal defects: An echocardiographic-surgical correlative study. Echocardiography. 2006;23:562–8. Source: Figures 18E to G reproduced with permission from Wang et al. Echocardiography. 2003;20:593–604.

diagnosis of intermediate ASVD.33 3D echocardiography can easily recognize the characteristic ASVD findings of an elongated and narrowed left ventricular outflow tract. Additionally, 3DE can identify the so called cleft within the left atrioventricular valve and evaluate its length, width, and rim size which is often a limitation of 2D TTE. After repair of an ASVD, left atrioventricular valve (LAVV) regurgitation is a common complication affecting greater than 10% of patients. These findings are likely related to postsurgical changes leading to increased valve diameter and consequent valve insufficiency.35,36 Knowing about this potential complication substantiates the need for a reliable imaging modality to diagnose and monitor progression of valvular disease.35 Live/real time 3D TTE is preferable to 2D TEE in evaluating the LAAV after ASVD

repair because of its ability to visualize the valve and its surrounding anatomy, in addition to the color Doppler capabilities. 3D TTE is also able to better evaluate valve morphology and function. 3D TEE is effective in measuring the size, shape, and location of the ASVD which correlates well with the actual surgical measurements.37 3D TTE can confirm data already obtained by 2D TTE, but the above mentioned cases indicate the advanced capabilities of 3D TTE in diagnosing complex CHD defects which 2D TTE often misses.

COMMON ATRIUM Common atrium is a type of ASVD that occurs as a result of absent atrial septal tissue and affixing of the

1748


A

B

C

D

E

F

Figs 74.19A to F


G

Figs 74.19A to G: Live/real time, three-dimensional transthoracic echocardiography in complete atrioventricular septal defects. (A) Arrow shows attachment of common atrioventricular valve to a papillary muscle in the right ventricle (Rastelli type B). No attachments were seen to the crest of the ventricular septum (arrowhead); (B) En face view shows all five leaflets of common atrioventricular valve; (C) En face view of the defect viewed from top and sides (arrows). Arrowhead points to atrial septum; (D) Arrowhead points to elongated and narrowed left ventricular outflow tract; (E) Shows absence of wedging of aorta (AO) in relation to common atrioventricular valve (CAV) annulus; (F) Arrowhead points to the vena contracta of CAV regurgitation jet. Its area measured 0.1 cm2. Color Dopplerguided continuous-wave Doppler interrogation of regurgitant jet showed a velocity time integral (VTI) of 79 cm. Regurgitant volume was calculated as 7.9 cm3; (G) Bicuspid aortic valve (AV). (AS: Anterosuperior leaflet; IB: Inferior bridging leaflet; L: Liver; LA: Left atrium; LV: Left ventricle; MI: Mural inferior leaflet; ML: Mural lateral leaflet; PA: Pulmonary artery; PV: Pulmonary valve; RA: Right atrium; RV: Right ventricle; RAV: Right atrioventricular valve; RVO: Right ventricular outflow tract; SB: Superior bridging leaflet). [Movie clips 74.19A, B, C, E, (Parts 1 to 3)]. Source: Reproduced with permission from Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006;23:598–606.

A

B

C

D

Figs 74.20A to D

1749

1750


E

Figs 74.20A to E: Live/real time, three-dimensional transthoracic echocardiography in partial atrioventricular septal defects. (A) Arrowhead points to a prominent cleft in the anterior leaflet of the left atrioventricular valve (LAV); (B) Arrows point to two left ventricular papillary muscles located close to each other; (C) Arrowhead points to a widened anteroseptal commissure (“cleft”) of the right atrioventricular valve (RAV); (D) Arrowhead points to an accessory LAV orifice; (E) Arrows point to the presence of only two scallops in the posterior leaflet of LAV. The black arrowhead points to the anterior leaflet of LAV. (AS: Anterosuperior leaflet; IB: Inferior bridging leaflet; L: Liver; LA: Left atrium; LV: Left ventricle; MI: Mural inferior leaflet; ML: Mural lateral leaflet; PA: Pulmonary artery; PV: Pulmonary valve; RA: Right atrium; RV: Right ventricle; RAV: Right atrioventricular valve; RVO: Right ventricular outflow tract; SB: Superior bridging leaflet). Movie clip 74.20C. Source: Reproduced with permission from Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006;23:598–606.

A

B

C

D

Figs 74.21A to D: Live/real time, three-dimensional transthoracic echocardiography (3DTTE) in atrioventricular septal defects (AVSDs). (A) Complete AVSD. Arrowhead shows attachment of CAV to the crest of the ventricular septum (Rastelli type A). Arrow points to atrial component of the defect; (B) Complete AVSD. Arrowhead points to an anomalous papillary muscle projecting into the left ventricular outflow tract causing subaortic obstruction; (C and D) Intermediate AVSD; (C) En face view of CAV shows superior bridging (SB) leaflet crossing over into the RV; (D) Both the AO and the PA are seen arising from the RV consistent with double outlet right ventricle. (AS: Anterosuperior leaflet; IB: Inferior bridging leaflet; L: Liver; LA: Left atrium; LV: Left ventricle; MI: Mural inferior leaflet; ML: Mural lateral leaflet; PA: Pulmonary artery; PV: Pulmonary valve; RA: Right atrium; RV: Right ventricle; RAV: Right atrioventricular valve; RVO: Right ventricular outflow tract; SB: Superior bridging leaflet). (Movie clips 74.21B and C). Source: Reproduced with permission from Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography 2006;23:598–606.


atrioventricular valves to the interventricular septum.38 3D TEE has been used to diagnose a common atrium with a cor triatriatum membrane and an associated cleft mitral valve leaflet (typically seen in common atrium) (Figs 74.22A to I). 2D TEE evaluated a prominence of the LA wall, but was unable to identify it as a cor triatriatum membrane and misdiagnosed these findings as a partial ASVD.

AORTOPULMONARY WINDOW An aortopulmonary window is a rare congenital anomaly involving a communication between the ascending aorta and the pulmonary artery. Echocardiography is the imaging modality of choice in diagnosing aortopulmonary window.39 The typical echocardiographic finding in patients with an aortopulmonary window is dilation of the

left atrium and ventricle secondary to chronic left-to-right shunting. 2D TTE has been the imaging modality of choice; however, there are obvious limitations that should be recognized. False positive results can occur in 2D TTE from artifactual dropouts designating 3D TTE as a better modality in diagnosing aortopulmonary window.40 The ability of 3D TTE to combine different data sets from various angles offers a better understanding of the defect and enhances the confidence of the diagnosis. The en face view of the defect offered by 3D TTE also allows for more accurate measurement of its dimensions (Figs 74.23 and 74.24).40

PATENT DUCTUS ARTERIOSUS (PDA) The ductus arteriosus is a normal connection during fetal life between the pulmonary artery and the descending

A

B

C

D

Figs 74.22A to D

1751

1752


E

F

G

H

I

Figs 74.22A to I: Three-dimensional transesophageal echocardiographic examination in cor triatriatum with common atrium. (A and B) The arrow points to the cor triatriatum membrane while the arrowheads (black) outline a large nonobstructive opening present within the membrane; (C) The common atrium (CA) with no atrial septum and the cor triatriatum membrane are well seen; (D to H) Show left and right upper pulmonary veins (LPV and RPV) located superior to the cor triatriatum membrane (arrows). 1 and 2 represent jets of right and left atrioventricular valve (RAV and LAV) regurgitation, respectively. Portions of both jets appear to move into the common atrium through the large opening in the cor triatriatum membrane. Short-axis view of left atrioventricular valve showing a cleft (C) in the anterior leaflet. (AV: Aortic valve; LVO: Left ventricular outflow; PL: Posterior left atrioventricular valve leaflet. RV: Right ventricle; LV: Left ventricle). Source: Reproduced with permission from Baweja G, Nanda NC, Kirklin JK. Definitive diagnosis of cor triatriatum with common atrium by three-dimensional transesophageal echocardiography in an adult. Echocardiography. 2004;21:303–6.


A

B

C

D

E

F

1753

Figs 74.23A to F: Live/real time, three-dimensional transthoracic echocardiographic assessment of aortopulmonary window. (A) Aortic short-axis view showing no evidence of an aortopulmonary window at this level. Movie clip 74.23, Part 2. The arrow points to the aortopulmonary window; (B) When the three-dimensional dataset was cropped posteroanteriorly, a large communication between the aorta (AO) and pulmonary artery (PA) was revealed (arrowhead); (C to E) The aortopulmonary window (arrowhead) could be viewed en face by cropping the 3D dataset from the side (C) and rotating it (D and E); (F) Color Doppler exam shows mild pulmonic regurgitation (PR). The arrowhead points to the aortopulmonary window. (AV: Aortic valve; LA: Left atrium; LPA: Left pulmonary artery; RPA: Right pulmonary artery). [Movie clip 74.23, (Parts 1 and 2)]. Source: Reproduced with permission from Singh A, Mehmood F, Romp RL, Nanda NC, Mallavarapu RK. Live/real time three-dimensional transthoracic echocardiographic assessment of aortopulmonary window. Echocardiography. 2008;25:96–9.

1754


A

B

C

D

Figs 74.24A to D: Live/real time, three-dimensional transthoracic echocardiographic assessment of aortopulmonary window. (A and B) Arrowhead points to the aortopulmonary window. Movie clip 74.24, Parts 1 to 2. The arrow points to the aortopulmonary window. The asterisk in Movie clip 74.24, Part 3 denotes the descending thoracic aorta; (C) Arrow points to the interrupted aortic arch. Arrowhead points to the aortopulmonary window; (D) Arrow points to a patent foramen ovale. (BCT: Brachiocephalic trunk; LCC: Left common carotid artery; LSA: Left subclavian artery; MV: Mitral valve; RA: Right atrium; TV: Tricuspid valve). [Movie clip 74.24, (Parts 1 to 3)]. Source: Reproduced with permission from Singh A, Mehmood F, Romp RL, Nanda NC, Mallavarapu RK. Live/real time three-dimensional transthoracic echocardiographic assessment of aortopulmonary window. Echocardiography. 2008;25:96–9.

thoracic aorta (Figs 74.25 to 74.28).41 Shortly after birth, the ductus arteriosus is expected to close, but in some patients it remains open and can persist into adulthood. Patent ductus arteriosus can be diagnosed by a variety of imaging modalities including 2D echocardiography (TTE, TEE), CT, and MRI. A study by Sinha et al. in 2004 sought to understand the usefulness of 3D TTE in the evaluation of PDA.42 2D TTE can diagnose a PDA, however, the assessment of the defect is often limited without the use of 3D TTE as well. 3D TTE can provide a realistic image of the PDA including its location, shape, length and width as well as en face visualization of its connections with the

pulmonary artery and descending thoracic aorta.42 3D TTE can determine the type of PDA which is useful in selecting optimal candidates for percutaneous intervention, the optimal anatomical approach for the procedure, and any expected risks or complications.

CONOTRUNCAL ANOMALIES Transposition of the Great Arteries Transposition of the great arteries (TGA) is organized into two distinct types: dextro (D-TGA) and levo (L-TGA;


1755

A

B

C

Figs 74.25A to C: Two-dimensional transthoracic echocardiography in an adult with patent ductus arteriosus. (A and B) Color Doppler examination demonstrates flow signals (arrowhead) moving between the main pulmonary artery (PA) and the descending thoracic aorta (DA) indicative of patent ductus arteriosus; (C) Color Doppler-guided continuous-wave Doppler examination demonstrates flow signals moving from PA to DA in systole and back into PA in diastole (arrowheads). The arrow points to the continuous-wave Doppler cursor line. (AO: Aorta; DA: Descending aorta; PA: Pulmonary artery; RPA: Right pulmonary artery). Source: Reproduced with permission from Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21:443–8.

A Figs 74.26A and B

B

1756


C

Figs 74.26A to C: Live three-dimensional transthoracic echocardiography in an adult with patent ductus arteriosus. B mode images. (A) The pyramidal section has been cropped to show the full extent of the PDA (arrowhead) which connects the PA to DA. The arrow points to the left atrial appendage; (B and C) The pyramidal section has been cropped from the top to show the opening of the PDA (arrowhead) into the pulmonary artery and its close location to the origin of the left pulmonary artery (arrow). (LPA: Left pulmonary artery; LV: Left ventricle; PV: Pulmonary valve). Source: Reproduced with permission from Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21:443–8.

A

B

C

D

Figs 74.27A to D


E

G

1757

F Figs 74.27A to G: Live three-dimensional transthoracic echocardiography in an adult with patent ductus arteriosus (PDA). Color Doppler images. The pyramidal section has been cropped to visualize flow signals in PA, PDA (arrowhead), and DA. (A) Shows the length of the PDA (arrowhead) connecting the PA and DA. The arrow points to an intercostal artery arising from DA; (B and C) Color Doppler images have been isolated by completely suppressing B mode images. The isolated color Doppler images could be rotated from 0° to 176°, thus enabling comprehensive visualization of flows in PA, PDA (arrowhead), and DA in three-dimensions. Images at 0° (top left), 45° (top right), 90° (lower left), and 176° (lower right) rotation are shown; (D) Frontal sections showing color Doppler signals moving from PA into DA in systole (left) and back into PA in diastole (right); (E and F) Tilted (top half) and enface (lower half) views of PDA (arrowheads) at aortic (E) and pulmonary (F) connections. On the right, B mode signals have been suppressed resulting in only flow visualization; (G) Schematic L, length of the ampulla, defined as the distance between the mid-portion of narrowest diameter of PDA and the mid-portion of the aortic end. This measured 0.94 cm in our patient. D, PDA diameter at aortic insertion (ampulla diameter). This measured 1.31 cm in our patient. (DA: Descending thoracic aorta; LPA: Left pulmonary artery; LV: Left ventricle; PV: Pulmonary valve; RV: Right ventricle). (Movie clip 74.27). Source: Reproduced with permission from Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21: 443–8.

Figs 74.29 to 74.37). D-TGA is characterized by ventriculoarterial discordance whereby the right ventricle pumps blood to the aorta and the left ventricle pumps blood to the pulmonary artery.43 A shunt lesion (ASD, VSD, or PDA) between the left and right side of the heart must be present to ensure appropriate mixing of pulmonary and systemic return to enable perfusion of oxygenated blood to the body’s vital organs. In an atrial switch surgery, deoxygenated blood is diverted from the inferior and superior vena cavae to the left side of the heart and from there into the pulmonary artery through the creation of an intra-atrial baffle.44 Senning and Mustard atrial switch procedures were historically the standard of

care for repair of TGA, however, long-term follow-up of these patients revealed significant morbidity associated with postprocedural complications. These complications include baffle leaks, tricuspid valve regurgitation, obstruction, arrhythmias, systolic dysfunction and even sudden death.45 The current recommended surgical approach is an arterial switch operation, which involves rearranging the aorta and pulmonary artery to the appropriate anatomical ventricle.46 L-TGA (or congenitally corrected TGA) is characterized most often by situs solitus with atrioventricular and ventriculoarterial discordance. In these patients, the right atrium connects to the left ventricle which pumps

1758


Fig. 74.28: Thoracic magnetic resonance angiogram with Gadolinium in the same patient as Figures 25 to 27. The arrowhead points to patent ductus arteriosus (PDA) viewed in the left lateral position. (DA: Descending thoracic aorta; PA: Pulmonary artery; RV: Right ventricle). Source: Reproduced with permission from Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21:443–8.

A

B

Figs 74.29A and B: Dextro-transposition of the great arteries. (A) The aorta (AO) arises from the right ventricle (RV); (B) The pulmonary artery (PA) originates from the left ventricle (LV). The arrows point to left and right branches of the main PA. (Movie clips 74.29A and B). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

deoxygenated blood to the pulmonary artery. The left atrium connects to the right ventricle which pumps oxygenated blood to the aorta.44 Patients with L-TGA often remain undiagnosed into adulthood unless they have coexisting congenital defects which prompt corrective repair in childhood. Signs and symptoms of right ventricular heart failure can develop in adulthood due to chronic pumping of the right ventricle against the higher systemic pressure often prompting further workup and eventual surgical repair.43

2D TTE is used to diagnose and monitor progression of disease in L-TGA and to assess for complications after corrective surgery of D-TGA, but 3D TTE has been shown to have valuable advantages over 2D imaging.44 A comprehensive view of the aortic and pulmonary valves with corresponding valve function is more easily obtained by 3D TTE compared to 2D TTE. Specifically, the tricuspid valve is most often affected in TGA and 3D TTE with its en face view and unique angles is capable of identifying each of three leaflets of the valve. The posterior or inferior


A

1759

B

Figs 74.30A and B: Levo-transposition (corrected transposition) of the great arteries. (A) The arrows point to two vena contractas of tricuspid regurgitation (TR) jets; (B) En face view of the two TR vena contractas (arrows). The movie clips show cropping of the tricuspid regurgitation jet (arrow) to view the vena contracta (arrowhead) en face in another patient with levo-transposition (corrected transposition) of the great vessels. (RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve). [Movie clip 74.30, (Parts 1 to 3)]. Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

A

C

B

Figs 74.31A to C: Dextro-transposition of the great arteries. In (A) the aortic valve (AV) and aorta are located anterior and to the right of the pulmonary valve (PV) and pulmonary artery. All four cardiac valves are visualized; In (B) the AV and aorta are located directly anterior to the PV and pulmonary artery. The arrow points to the intra-atrial baffle; C shows normal relationship of the semilunar valves and the great arteries in a patient without transposition of the great arteries. The PV and the pulmonary artery are located anterior and to the left of the aorta and the AV. All four cardiac valves are visualized. (MV: Mitral valve; TV: Tricuspid valve). (Movie clips 74.31A to C). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

1760


Fig. 74.32: Dextro-transposition of the great arteries. Multiple anatomic defects are present in the tricuspid valve (TV) which is viewed en face in the closed position in systole. Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

A

C

B

Figs 74.33A to C: Dextro-transposition of the great arteries. (A and B) The arrow points to a cleft in the anterior mitral valve (MV) leaflet; (C) The arrow points to a narrow left ventricular outflow tract. Systolic anterior movement of the anterior mitral leaflet (AML) is also seen. The data set was cropped from the top. (RV: Right ventricle; VS: Ventricular septum). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.


A

B

C

D

1761

Figs 74.34A to D: Dextro-transposition of the great arteries. (A and B) The intra-atrial baffle (B) appears as a shelf when viewed en face by cropping from the bottom. A defect in the baffle is not well seen in the illustration but it is clearly visualized (arrowhead) in the accompanying movie clips which view the baffle en face; (C) Shows the relationship of the baffle to the inferior vena cava (IVC); (D) Color Doppler study shows systemic venous flow signals (arrow) moving through the left ventricle (LV) toward the pulmonary artery (PA). (SVA: Systemic venous atrium). [Movie clip 74.34, (Parts 1 and 2)]. Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

tricuspid leaflet is frequently visualized poorly by 2D TTE requiring assistance from 3D imaging. With regard to function, 3D TTE reveals deficiencies in leaflet coaptation, prolapse of leaflet components, and provides specific details on the defect within the valve itself. Over time, the severity of valvular regurgitation should be monitored and progressively worsening function can be evaluated by 3D TTE by visualizing the shape and measuring the area of the vena contracta, a function lacking in 2D TTE. The vena contracta basically relates to the “hole” in a valve through which regurgitation occurs and hence accurate

measurement of its size is important in determining regurgitation severity. The product of the area of vena contracta assessed by 3D TTE and the velocity time integral of the regurgitation jet obtained by continuouswave Doppler provides an accurate estimate of the volume of regurgitation.44 In addition to the tricuspid valve, 3D TTE is unique in offering multiple views of the pulmonic valve and can detect systolic anterior motion of the mitral valve and left ventricular outflow tract obstruction (affecting up to one-third of patients with TGA who have undergone an atrial switch operation) with significant

1762


Fig. 74.35: Dextro-transposition of the great arteries. The arrow points to a shelf-like intra-atrial baffle located behind the pulmonary artery (PA) in another patient. Note the anterior and leftward position of the aortic valve and aorta (AO) in relation to the pulmonary valve and pulmonary artery (PA). (TV: Tricuspid valve). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

A

C

B

Figs 74.36A to C: Dextro-transposition of the great arteries. (A) Color Doppler examination. The arrow points to a defect in the intra-atrial baffle (B); (B) En face view of the leak (arrow) at the origin (vena contracta); (C) Arrow points to the defect in the baffle seen after suppression of color Doppler flow signals. (PVA: Pulmonary venous atrium; SVA: Systemic venous atrium). (Movie clip 74.36). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.


1763

difficulty in performing such a comprehensive evaluation.36 3D TTE can supplement 2D TTE with precise measurement of the size and shape of a VSD. Based on the usefulness of 3D TTE in monitoring pulmonary regurgitation and its severity, cardiologists can recognize high risk patients and monitor progression of disease closely.

Coronary Artery Anomalies

Fig. 74.37: Dextro-transposition of the great arteries. Arrow points to a leak in the intra-atrial baffle (B) in another patient. (IVS: interventricular septum). Source: Reproduced with permission from Enar S, Singh P, Douglas C, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26:1095–104.

anatomical detail.44 Follow-up of patients who have had an atrial switch surgery relies heavily on the ability of 3D TTE to evaluate for postprocedure complications such as baffle leaks (up to 40% of patients after Mustard procedure) or obstruction, functions that are often limited by 2D TTE.44,47 Ahmed et al. described an intra-atrial baffle obstruction years after surgical repair of a TGA diagnosed by 3D TTE based on its ability to view the defect en face in the short axis.

Tetralogy of Fallot ToF is a complex cyanotic CHD defect that includes VSD, overriding aorta, pulmonary outflow tract obstruction and right ventricular hypertrophy. Surgical repair is necessary early in life and these patients require close followup to monitor for possible complications. Postsurgical ToF patients can experience severe pulmonary valve regurgitation or right ventricular outflow obstruction. Very rarely, patients may have residual VSDs.48 3D TTE has demonstrated its superiority compared to 2D imaging in assessing pulmonary regurgitation severity based on visualization of the vena contracta.49 Accurate assessment of the size and shape of residual defects is crucial for determining if repeat surgery is necessary and 2D TTE, especially in the setting of other congenital anomalies, has

Anomalous coronary artery (ACA) is not an uncommon diagnosis and may be underestimated due to the fact that only 20% of patients with this structural abnormality will present with symptoms.50 Common presentations include myocardial infarction, arrhythmias, angina, syncope, and even sudden death.50,51 Complications from ACA are more likely to occur when coronary arteries are anatomically located between the aorta and the pulmonary arteries. Obstruction of blood flow likely occurs secondary to compression between the great vessels or acute angulations in the coronary arteries.51 Coronary angiography remains the gold standard for diagnosing anomalous coronary arteries, however, less invasive imaging with echocardiography can provide useful information that angiography often misses.50 Multiplane 2D TEE and 3D reconstruction can often provide similar findings in ACA, but the 3D images offer supplemental data used to increase the confidence of the diagnosis.51 3D TTE has previously been used to assess proximal coronary arteries; however, Vengala et al. in 2003 demonstrated additional capabilities of 3D TTE in evaluation of coronary anatomy.52 ACAs first detected by 3D TTE were later confirmed with angiography, validating its use. The en face view and unique maneuvering in multiple geometric planes offered by live/real time 3D TTE depicts the origin and course of the coronary artery. Coronary angiography often has difficulty in visualizing the anomalous vessel between the aorta and the pulmonary artery, which as described above carries a greater risk of complications.51 Both 2D and 3DE can diagnose an anomalous origin of the left coronary artery from the pulmonary artery, but 3D TTE can also visualize the opening of the ACA en face and its connections to the aorta and pulmonary artery (Figs 74.38 and 74.39).53 This presentation requires immediate surgical correction that previously consisted of creating a tunnel between the aorta and the pulmonary artery reversing blood flow into the aorta. 3D TTE was capable of tracking the tunnel between the aorta and

1764

A

C

E


B

D Figs 74.38A to E: Two-dimensional transesophageal and transthoracic echocardiography in an adult with anomalous origin of the left coronary artery from the pulmonary artery. (A and B) Intraoperative transesophageal study shows a dilated right coronary artery (RCA, A) and the surgically created tunnel (T, B); (C to E) Transthoracic study (performed 13 years after surgery). The arrow in C shows a small defect in the tunnel (T) near the aorta through which shunting occurs into the pulmonary artery (arrowhead in D). Color Doppler-guided continuous-wave Doppler examination (E) shows shunting occurring practically throughout the cardiac cycle (arrowheads). The arrow in E points to the Doppler cursor line. (AO: Aorta; LA: Left atrium; LPA: Left pulmonary artery; PR: Pulmonary regurgitation; PV: Pulmonary valve; RA: Right atrium; RPA: Right pulmonary artery; RVOT: Right ventricular outflow tract). Source: Reproduced with permission from Ilgenli TF, Nanda NC, Sinha A, Khanna D. Live three-dimensional transthoracic echocardiographic demonstration of anomalous origin of left coronary artery from the pulmonary artery. Echocardiography. 2004;21:559–62.


A

B

C

D

E

F

Figs 74.39A to F

1765

1766


G

pulmonary artery and Doppler functions were used to confirm the tunnel-pulmonary artery shunting.53 Based on the 3D views, the area of the defect was measured and shunt volume into the pulmonary artery was calculated. Nowadays, surgeons just reimplant the coronary artery between the pulmonary artery and the aorta. Diagnosis of the left main coronary artery fistula to the left ventricle has also been made by 3D TTE (Figs 74.40A and B).54

OUTFLOW TRACT OBSTRUCTION Congenital Aortic Stenosis/Bicuspid Aortic Valve The most common cause of aortic stenosis (AS) in adults is acquired, related to calcific degeneration of the valve, but congenital AS, most notably from bicuspid aortic valve (BAV), is a clinically relevant abnormality. When a patient presents with symptoms of AS prior to the seventh decade of life, the diagnosis of BAV should be strongly considered. In addition to AS, aortic regurgitation (AR), infective endocarditis, and aortic dissection have all been linked to BAV.55 Compared to 2D TTE, 3D TTE offers better images of the aortic valve, especially the visualization of the individual leaflets.56 The identification of redundant aortic valve leaflets are relevant in distinguishing the development of AS versus AR based on the BAV closure down the midline.1 3D TTE is able to recognize redundancy of aortic valve leaflets and offer prognostic information, a feature 2D

Figs 74.39A to G: Live three-dimensional transthoracic echocardiographic demonstration of anomalous origin of left coronary artery from the pulmonary artery. (A) The arrowhead points to the orifice of the anomalous coronary artery while the arrow shows the defect in the tunnel; (B and C) Color Doppler examination. In B, flow signals (arrowhead) are seen moving into the orifice of the anomalous coronary artery from the tunnel (T). The arrow points to the tunnel-pulmonary artery shunt. In C, the arrow points to color Doppler shunt flow signals visualized in three dimensions; (D) Coronary angiogram. Arrowhead points to fistula originating from the left anterior descending coronary artery (LAD) and draining into the pulmonary artery (PA) which is partially opacified. (E to G) Live three-dimensional transthoracic echocardiography; E. Arrowhead points to a small localized area of abnormal flow signals in the pulmonary artery (PA) just distal to the pulmonary valve (PV) in both diastole (F) and systole (G) consistent with entrance of the fistula into the PA. The arrow in F points to mild pulmonary regurgitation. (AV: aortic valve; CX: Circumflex coronary artery; LM: Left main coronary artery; RVO: Right ventricular outflow tract). (PA: Main pulmonary artery; AO: Aorta; LA: Left atrium; LPA: Left pulmonary artery; PR: Pulmonary regurgitation; PV: Pulmonary valve; RA: Right atrium; RPA: Right pulmonary artery; RVOT: Right ventricular outflow tract). Source: Figure 74.39A to C Reproduced with permission from Ilgenli TF, Nanda NC, Sinha A, Khanna D. Live three-dimensional transthoracic echocardiographic demonstration of anomalous origin of left coronary artery from the pulmonary artery. Echocardiography. 2004;21:559–562. Source: Figure 74.39D Reproduced with permission from Mehta D, Nanda NC, Vengala S, Mehmood F, Taylor J. Live three dimensional transthoracic echocardiographic demonstration of coronary artery to pulmonary artery fistula. Am J Geriatric Cardiol. 2005;14:42–4. Source: Figures 74.39E to G Reproduced with permission from Mehta D, Nanda NC, Vengala S, Mehmood F, Taylor J. Live three dimensional transthoracic echocardiographic demonstration of coronary artery to pulmonary artery fistula. Am J Geriatric Cardiol. 2005;14:42–4.

TTE is unable to perform (Figs 74.41 to 74.43).56 Leaflet perforation is an unfortunate complication that can result in significant AR which has been visualized by 3DE. Quadricuspid aortic valves, although rare, have been diagnosed by 3D TTE. Burri et al. described a young female patient scheduled to undergo aortic valve surgery for AR who was misdiagnosed with BAV based on 2D echocardiographic findings (Figs 74.44A to C).57 On further investigation of the valve with preoperative 3D TTE and intraoperative multiplane TEE, images were consistent with a quadricuspid aortic valve (Figs 74.45A and B). Understanding the capabilities of 3D TTE and analyzing the valve carefully from each echocardiographic view can be instrumental in making a diagnosis that was previously missed. In this case, a quadricuspid aortic valve was visualized in the parasternal short-axis view, but not in the parasternal long-axis view.


A

1767

B

Figs 74.40A and B: Live/real time, three-dimensional transthoracic echocardiographic detection of left main coronary artery fistula into the left ventricle. (A and B) The arrowhead in A points to the enlarged left main coronary artery (LM). Its entrance into the left ventricle (LV) is denoted by an arrowhead in (B). (AO: Aorta). (Movie clips 74.40A and B).

A

B

Figs 74.41A and B: Two-dimensional transthoracic echocardiography in an adult patient with bicuspid aortic valve and severe aortic regurgitation. (A) The bicuspid aortic valve (AV) is shown in systole in the open position with no evidence of stenosis; (B) Color Doppler examination shows an eccentric jet of aortic regurgitation originating posteriorly (horizontal arrow). The vertical arrow points to mild pulmonic regurgitation. (PV: Pulmonic valve; RA: Right atrium; RV: Right ventricle). (Movie clips 41A and B). Source: Reproduced with permission from Singh P, Dutta R, Nanda NC. Live/real time three-dimensional transthoracic echocardiographic assessment of bicuspid aortic valve morphology. Echocardiography. 26.:4:478–80.

It is important to recognize that 2D echocardiography with Doppler tends to overestimate the severity of stenotic lesions due to the pressure recovery phenomenon and the presence of localized high velocities (and gradients) which may not reflect the true gradient across the stenotic valve or subvalvar membrane. Also, 3DE is particularly useful in characterizing adjacent stenotic lesions in tandem such as

aortic valve stenosis and supravalvar stenosis in the same patient. This feature cannot be done in 2D Doppler which will simply give the maximum gradient obtained from both areas but cannot identify the severity of each individual lesion. A major advantage of 3D over 2D echocardiography is the ability to systematically crop the 3D data sets in a sequential manner such that an en face view of the valve

1768


A

B

Figs 74.42A and B: Live/real time, three-dimensional transthoracic echocardiography in the same patient. (A) Note the presence of several folds in the bicuspid aortic valve in the closed position viewed from the ventricular side; (B) The arrow points to a well circumscribed perforation in the posterior cusp of the aortic valve. (LA: Left atrium; PV: Pulmonic valve; RA: Right atrium; RV: Right ventricle). (Movie clips 74.42A and B). Source: Reproduced with permission from Singh P, Dutta R, Nanda NC. Live/real time three-dimensional transthoracic echocardiographic assessment of bicuspid aortic valve morphology. Echocardiography. 26;4:478–80.

A

B

Figs 74.43A and B: Two-dimensional transthoracic echocardiography. (A and B) The aortic valve (AV) appears bicuspid. (LA: Left atrium; RV: Right ventricle). (Movie clip 74.43). Source: Reproduced with permission from Burri MV, Nanda NC, Singh A, Panwar SR. Live/real time three-dimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007;24:653–5.

orifice is obtained at the level of the valve tip where the stenosis is most significant. This can then be planimetered providing an accurate estimate of the stenosis severity. 3DE is also useful in making sure that the cutting plane in the 3D data set is exactly parallel to the plane of the valve orifice preventing inaccuracies introduced by

oblique planes. With 2D echocardiography, it is not always possible to be certain that one is visualizing the valve at its tip and it is difficult to determine whether the plane is parallel or oblique in relation to the valve orifice. This is because, at any given time, 2D echocardiography provides only a thin slice-like view of a cardiac structure such as the


A

C

A

1769

B

Figs 74.44A to C: Multiplane two-dimensional transesophageal echocardiography. (A and B) Four aortic valve (AV) leaflets (numbered in B) are well seen. The arrow in A points to diastolic noncoaptation of AV leaflets which resulted in significant aortic regurgitation. C. The arrow points to severe aortic regurgitation. (AO: Aorta, RA: Right atrium). (Movie clip 74.44A and B). Source: Reproduced with permission from Burri MV, Nanda NC, Singh A, Panwar SR. Live/real time three-dimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007;24:653–5.

B

Figs 74.45A and B: Live/real time, three-dimensional transthoracic echocardiography. (A and B) Shows a quadricuspid aortic valve with four numbered leaflets clearly visualized. (AO: Aorta, RA: Right atrium; TV: Tricuspid valve.). [Movie clip 74.45, (Parts 1 and 2)]. Source: Reproduced with permission from Burri MV, Nanda NC, Singh A, Panwar SR. Live/real time three-dimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007;24:653–5.

1770


aortic valve. This is unlike a 3DE data set that includes the whole valve which can then be studied at any time using any desired plane and angulation.

Subaortic Stenosis Stenosis can occur not only at the level of the valve but above the valve (supravalvular) as well as below the valve (subvalvular or subaortic). When subaortic stenosis is diagnosed it is important to distinguish the fixed from the dynamic type. Fixed subaortic stenosis can be due to a focal, fibromuscular membrane or a diffuse tunnel-type lesion. On the other hand, dynamic subaortic stenosis can develop as a result of systolic anterior motion of the mitral valve, a common echocardiographic finding in patients with hypertrophic cardiomyopathy.1 Interestingly, there is a strong association between patients previously diagnosed with a VSD and subaortic stenosis which appears to be related to fibrous tissue formation from turbulent blood flow at the prior surgical site.58 With 3D TTE, the aortic valve, subaortic membrane, and surrounding cardiac anatomy is clearly visualized which is beneficial in measuring the severity of stenosis (Figs 74.46 and 74.47).1,59,60 2D TTE can be helpful in diagnosing subaortic stenosis based on Doppler measurement of gradient across the membrane, however, these calculations are often inaccurate. In a study by

A

Bandarupalli et al. the measurement of valve gradient and orifice area by 2D TTE was indicative of severe obstructive disease, but follow-up calculations by 3D TTE with the subaortic membrane en face from the left ventricular outflow tract were indicative of insignificant stenosis.60 Left heart catherization was performed to confirm the echocardiographic findings, and in fact was consistent with those obtained by 3D TTE (Fig. 74.48). 3D TTE is more reliable because it evaluates the subaortic membrane in its entirety and locates the defect in the membrane (Figs 74.49 to 74.51).59 The defect was viewed en face by rotation and cropping of data sets, a technology unique to 3DE. Furthermore, 3D TTE images can identify the “hole in a hole” which is diagnostic of subaortic stenosis.

AORTIC ARCH ANOMALIES Coarctation of the Aorta The diagnosis of coarctation of the aorta is often missed prenatally and immediately after birth manifesting as shock, once closure of the ductus arteriosus occurs.61 Later in life, patients with coarctation of the aorta present with significant differences in blood pressure readings between the upper and lower extremities. If not repaired, patients are at risk of developing symptoms of congestive heart failure, aortic rupture, and endocarditis.58 Percutaneous

B

Figs 74.46A and B: Two-dimensional transthoracic echocardiogram in discrete subaortic membranous stenosis. (A) The arrowhead points to the subaortic membrane; (B) Using color Doppler-guided continuous-wave Doppler, a peak gradient (PG) of 134 mm Hg (arrow) was obtained across the left ventricular (LV) outflow tract. (AO: Aorta; LA: Left atrium; RV: Right ventricle; RVO: Right ventricular outflow tract). Source: Reproduced with permission from Agrawal GG, Nanda NC, Htay T, Dod HS. Live three-dimensional transthoracic echocardiographic identification of discrete subaortic membranous stenosis. Echocardiography. 2003;20:617–9.


A

C

1771

B

Figs 74.47A to C: Live three-dimensional transthoracic echocardiography in discrete subaortic membranous stenosis. (A and B) The arrowhead points to a narrow opening in the membrane imaged in short axis; (C) Membrane (arrowhead) viewed from the top showing its attachment to the ventricular septum (VS) and the anterior leaflet of the mitral valve. (AO: Aorta; RA: Right atrium). The arrowhead in the Movie clip 74.47 points to the obstructing membrane. (Movie clip 74.47). Source: Reproduced with permission from Agrawal GG, Nanda NC, Htay T, Dod HS. Live three-dimensional transthoracic echocardiographic identification of discrete subaortic membranous stenosis. Echocardiography. 2003;20:617–9.

Fig. 74.48: Discrete subaortic membrane. Cardiac catheterization pressure tracings showing no significant gradient across the LV outflow tract. Source: Reproduced with permission from Bandarupalli N, Faulkner M, Nanda NC, Pothineni KR. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: Correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008;25:1004–6.

1772


A

B

Figs 74.49A and B: Discrete subaortic membrane. Two-dimensional transthoracic echocardiography. (A) Arrowhead points to the membrane imaged in the parasternal long-axis view; (B) Shows peak and mean pressure gradients of 64 mm Hg and 31 mm Hg across the left ventricular outflow tract by continuous-wave Doppler. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle). (Movie clip 74.49). Source: Reproduced with permission from Bandarupalli N, Faulkner M, Nanda NC, Pothineni KR. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: Correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008;25:1004–6.

A

B

Figs 74.50A and B: Discrete subaortic membrane. Live/real time, three-dimensional transthoracic echocardiography. (A and B) Subaortic membrane (arrowhead) and orifice viewed en face. The orifice measured 2.29 cm2 by planimetry. (LA: Left atrium; PV: Pulmonic valve; RA: Right atrium; RV: Right ventricle). (Movie clip 74.50). Source: Reproduced with permission from Bandarupalli N, Faulkner M, Nanda NC, Pothineni KR. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: Correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008;25:1004–6.

balloon angioplasty with or without stent placement is becoming more popular as the treatment option for young adult patients with coarctation of the aorta, while surgery remains an option for those not candidates for percutaneous

approach. Evaluating a patient for coarctation of the aorta includes 2D TTE with continuous-wave Doppler focusing on the identification of diminishing anterograde flow during diastole to confirm hemodynamically significant stenosis.58


1773

Fig. 74.51: Discrete subaortic membrane. Live/real time, threedimensional transthoracic echocardiography. Aortic valve orifice viewed en face. It measured 2.94 cm2 by planimetry. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle). Source: Reproduced with permission from Bandarupalli N, Faulkner M, Nanda NC, Pothineni KR. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: Correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008;25:1004–6.

Fig. 74.52: Real time, two-dimensional transesophageal echocardiogram in aortic arch vasum vasi to pulmonary artery fistula. The arrowhead points to flow signals moving from the wall of the aortic arch (AO) into the main PA. (Movie clip 74.52). Source: Reproduced with permission from Sadat K, Pradhan M, Nanda NC, Joshi D, Diddi HP. Two- and three-dimensional transthoracic echocardiography in the assessment of aortic arch vasum vasi to pulmonary artery fistula. Echocardiography. 2013;30:219–24.

2D TTE has traditionally been used to make the diagnosis of aortic arch abnormalities, but understanding its limitations allows for the use of more advanced technology.62 For example, postsurgical repair of coarcation of the aorta results in a tortuous aortic arch which makes evaluation by 2D TTE difficult. 3D TTE can create an “echocardiographic angiogram” and rotate images in various angles and planes providing the cardiologist with a detailed understanding of the extravascular cardiac anatomy.63

correct diagnosis. The diagnosis was confirmed based on calculations of flow acceleration within the aortic wall, the pressure within the fistula itself, and the gradient between the aorta and the pulmonary artery.64

Aortic Arch to Pulmonary Artery Fistula Aortic lumen to pulmonary artery fistulas (APAF) is extremely rare, and APAF forming from the vasum vasi in the posterior wall of the aortic arch is even more rare.64 2D TEE demonstrated turbulent blood flow in the main pulmonary artery moving from a direction not consistent with the lumen as the site of origin. Further evaluation with 3D imaging from various angles actually identified the fistula beginning in the posterior wall of the aortic arch likely from a vasum vasi (Figs 74.52 and 74.53). 3D TTE confidently assessed the fistula at its origin with its en face view and aided 2D TTE in confidently making the

ATRIAL AND ATRIOVENTRICULAR VALVE ABNORMALITIES Cor Triatriatum Sinister Cor triatriatum sinister is a rare CHD characterized by a fibromuscular membrane located in the left atrium superior to the LA appendage.65 The location of the membrane distinguishes this entity from a mitral supravalvular membrane which is located below the LA appendage. The size of the defect in the membrane is indirectly proportional to the degree of obstruction of blood flow and subsequent hemodynamic significance. 2D echocardiography has traditionally been the imaging modality of choice for the diagnosis of cor triatriatum sinister, however 3D imaging offers greater precision in assessing the size and shape of the defect within the membrane.65 3D TTE visualizes the membrane en face leaving the cardiologist with a better

1774


A

B

Figs 74.53A and B: Live/real time, three-dimensional transthoracic echocardiogram in aortic arch vasum vasi to pulmonary artery fistula. (A) The arrowhead points to abnormal flow signals originating within the posterior wall of the aortic arch. A small area of flow acceleration is also noted. Careful cropping revealed no connection of this abnormal flow signals with the aortic lumen; (B) En face view of the fistula vena contracta. It is very small measuring 1.7 mm in diameter, area 3.5 mm2. (LA: Left atrium). (Movie clips 74.53A and B).

A

B

Figs 74.54A and B: Live/real time, three-dimensional transthoracic echocardiography in cor triatriatum sinister. (A) Arrowhead points to cor triatriatum membrane (M), which is located superior to left atrial appendage (LAA); (B) Arrowhead (arrow in movie) points to a large opening in cor triatriatum membrane visualized en face. The dimensions were 3.06 × 1.03 cm and area 2.3 cm2. (LA: Left atrium; LV: Left ventricle; LVO: Left ventricular outflow tract; RA: Right atrium; RV: Right ventricle). (Movie clip 74.54). Source: Reproduced with permission from Patel V, Nanda NC, Arellano I, Yelamanchili P, Rajdev S, Baysan O. Cor triatriatum sinister: Assessment by live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2006;23:801–2.

understanding of the defect (Figs 74.54A and B). 3D TTE can accurately diagnose cor triatriatum sinister based on the echocardiographic characteristics described above and quantify the size of the defect which is valuable in understanding its clinical significance.65 Conversely, 2D TTE was able to make the diagnosis, but could not comment on the size and shape of the defect and thus could

not comment on the clinical relevance of the defect. In the late 1990s, Samal et al. described offline 3D reconstruction of 2D TTE images for enhanced visualization of cor triatriatum sinister along with other atrial membrane defects.66 With the creation of 3D images, the exact size, shape, and location of the membrane defect was known to the cardiologist and surgeon which was valuable in planning for surgical repair.


A

C

1775

B Figs 74.55A to C: Live three-dimensional transthoracic echocardiographic assessment of isolated cleft mitral valve. The arrowhead points to the cleft in the anterior mitral valve leaflet seen in the open (A and B) and closed (C) positions. (LV: Left ventricle; PML: Posterior mitral leaflet; RV: Right ventricle). The cleft is directed toward the left ventricular outflow tract unlike the atrioventricular septal defect where the cleft points medially. Movie clip 74.55, Parts 1 and 2 from another patient shows an isolated cleft (arrow) in the anterior mitral leaflet in a 28-year-old female. Color Doppler examination shows prominent regurgitation (arrowhead) into the left atrium through the cleft. [Movie clip 74.55, (Parts 1 and 2)]. Source: Reproduced with permission from Sinha A, Kasliwal RR, Nanda NC, et al. Live three-dimensional transthoracic echocardiographic assessment of isolated cleft mitral valve. Echocardiography. 2004;21:657–61.

Isolated Mitral Valve Cleft

Ebstein’s Anomaly

Isolated mitral valve cleft is a rare congenital defect that may cause mitral regurgitation. The direction the cleft faces helps to distinguish an AVSD (toward the ventricular inlet septum) from isolated mitral valve cleft (toward the left ventricular outflow tract), a feature easily performed by 3D TTE.67,68 The diagnosis of isolated mitral valve cleft is often missed by 2D TTE making 3D TTE a more enticing imaging modality. In patients with mitral valve prolapse, the diagnosis of isolated mitral valve cleft by 2D TTE is especially difficult because of the redundant leaflets. Compared to 2D TTE, 3D TTE visualizes the cleft in the anterior mitral valve leaflet from multiple viewpoints ensuring greater confidence in the diagnosis. In addition, it provides accurate dimensions of the defect and the mitral rim and vena contracta measurements give reliable assessment of the severity of the resultant mitral regurgitation (Figs 74.55 and 74.56).67

Ebstein’s anomaly is a rare congenital defect affecting less than 1% of patients with CHD that is characterized by the attachment of tricuspid valve leaflets, often the septal and posterior leaflets, to the walls of the right ventricle and ventricular septum.69 The tethering of the septal leaflet to the ventricular septal wall causes an “apparent displacement” of these structures in the direction of the right ventricular apex that is characteristically seen on 2D TTE. Despite these findings, 2D TTE has difficulty identifying other important morphological features of Ebstein’s anomaly. Due to the limitations of the 2D TTE, 3D TTE can be used in patients with Ebstein’s anomaly because it can visualize each individual leaflet and the tethering to the right ventricular free wall or ventricular septum (Fig. 74.57).70 Based on the comprehensive view of the leaflets offered by 3D TTE, the size and location of the

1776


A

B

C

D

Figs 74.56A to D: Live three-dimensional transthoracic echocardiographic assessment of isolated cleft mitral valve. (A to C) The arrowhead points to the cleft in the anterior mitral valve leaflet. Note thickened mitral leaflets with a narrow orifice indicative of associated mitral stenosis; (D) Isolated cleft mitral valve in another child. This en-face transthoracic three-dimensional view shows the cleft (arrow) dividing the superior and inferior components of the anterior mitral leaflet. Note the perception of the depth of the cleft with threedimensional imaging. (MV: Mitral valve; LV: Left ventricle; PML: Posterior mitral leaflet; RV: Right ventricle). (Movie clip 74.56D). Source: Figures 74.56A to C reproduced with permission from Sinha A, Kasliwal RR, Nanda NC, et al. Live three-dimensional transthoracic echocardiographic assessment of isolated cleft mitral valve. Echocardiography. 2004;21:657–61.

tethered and nontethered parts of the leaflets can be better evaluated, which is relevant when the patient is evaluated for tricuspid valve repair. A surgeon’s understanding of the amount of nontethered leaflet tissue is crucial in selecting appropriate candidates for valve repair, a function that 3DE has nearly mastered. The nontethered leaflets of the tricuspid valve are known to extend outward creating a bubble-like appearance on 3D imaging that is diagnostic of Ebstein’s anomaly (Figs 74.58 and 74.59).70 It is important to recognize that not all tethered areas can be viewed en face by 3D TTE, one obvious limitation preventing a complete understanding of the severity of this anomaly.

OTHER ABNORMALITIES Chiari Network Chiari network is often clinically insignificant, but some reports suggest increased risk of thrombus formation, paradoxical embolization, or endocarditis.71 Chiari network is composed of a large fenestrated membrane in the right atrium with wide attachments at the crista terminalis and interatrial septum as a result of persistence of the right-sided sinus venosus valve. 3D TTE is valuable in distinguishing Chiari network from Eustachian and Thebesian valves based on their smaller size and location,


A

C

A Figs 74.58A and B

1777

B Figs 74.57A to C: Live/real time, three-dimensional transthoracic echocardiography in Ebstein’s anomaly associated with transposition of the great vessels. (A) Four-chamber view shows apparent displacement of the attachment of the septal leaflet of the tricuspid valve (TV) toward the apex; (B) Tethering of the septal leaflet of the TV results in a bubble-like appearance (yellow arrowhead) in the middle portion of the ventricular septum as the nontethered portion moves toward closure during systole. This transverse section was taken at a level denoted by #1 in (A); (C) Transverse section taken at a more inferior level (#2 in A) demonstrates bubble-like appearance of both septal (yellow arrowhead) and posterior (black arrowheads) TV leaflets produced by tethering. (a: Anterior TV leaflet; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Patel V, Nanda NC, Rajdev S, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of Ebstein’s Anomaly. Echocardiography. 2005;22:847–54.

B

1778


C

D

E

F

G

H

Figs 74.58C to H


I and cor triatriatum dexter network based on its thickness with few or absent fenestrations (Figs 74.60 and 74.61). Other clinical clues suggesting the diagnosis of cor triatriatum dexter are obstruction of blood flow and its frequent association with other congenital defects. 2D TTE has diagnosed a defect as a Eustachian valve but followup imaging with 3D TTE confirmed the diagnosis of Chiari network.71

DOUBLE OUTLET RIGHT VENTRICLE Double outlet right ventricle is a congenital anomaly whereby the aorta and main pulmonary artery are connected (entirely or partly) to the morphologic right ventricle. The presence of a VSD almost always accompanies this diagnosis (Fig. 74.62). Some experts consider double outlet right ventricle on a spectrum with other CHDs including ToF in the presence of a VSD and/or pulmonary stenosis as well as TGA.72 The recommended surgical repair includes creation of a baffle that connects the aorta to the left ventricle through the VSD. Other surgical options include arterial switch procedures. In planning for the proper repair procedure, a comprehensive evaluation of the location and size of the VSD and its proximity to the semilunar valves as well as the relationship of the aorta and main pulmonary artery to each other is essential.72,73 Surgeons have long relied on 2D echocardiography, however, 3DE has become a feasible imaging option and offers significant advantage in the visualization of cardiac anatomy and in obtaining the necessary measurements related to double outlet right ventricle. Specifically, 3D imaging can crop images to better visualize the atrioventricular valves, the VSD, and the great vessels in a single echocardiographic window. This information

1779

Figs 74.58A to I: Live/real time, three-dimensional transthoracic echocardiography in isolated Ebstein’s anomaly. (A) Transverse section taken at the apex of TV shows a large area of noncoaptation (N) as well as tethering and bubble-like appearance of anterior (yellow arrows) and posterior (black arrowhead) TV leaflets; (B to D) Transverse sections taken more basally demonstrate multiple “bubbles” in the septal (yellow arrowheads) and posterior (black arrowheads) TV leaflets. Inset in D shows all three leaflets of the tricuspid valve in the open position; (E) Oblique section shows multiple “bubbles” (black arrowheads) in the posterior (p) TV leaflet produced by tethering to RV inferior wall. Inset in E shows a long snake-like posterior (p) TV leaflet; (F) The oblique section shown in E has been rotated to more optimally view the attachment of posterior (p) TV leaflet to the RV inferior wall; (G) The arrowhead in another patient with Ebstein’s anomaly shows a bubble-like appearance resulting from tethering of the septal leaflet (s) of the tricuspid valve to the ventricular septum; (H and I) The arrowhead points to a large defect in the anterior leaflet of the tricuspid valve in a different patient with Ebstein’s anomaly. Note also small, discrete nodular areas of thickening on the anterior tricuspid leaflet. Asterisks represent loss of tricuspid valve tissue which is considerable in this patient. The septal leaflet of the tricuspid valve was tethered to the ventricular septum. (a: Anterior tricuspid valve leaflet; AV: Aortic valve; LV: Left ventricle; RV: Right ventricle; P: Posterior tricuspid valve leaflet). [Movie clips 74.58B, 58D, 58D (inset), 58E (inset), and 58F, 58G, 58H]. Source: Figure 58A to F reproduced with permission from Patel V, Nanda NC, Rajdev S, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of Ebstein’s Anomaly. Echocardiography. 2005;22:847–54. Source: Figure 58G to I Reproduced with permission from Pothineni K, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: incremental value over the two-dimensional technique. Echocardiography. 2007;24: 541–52.

improves understanding of the defect and helps members of the medical team to plan for surgical repair.73 3D imaging can predict if a repaired baffle between the left ventricle and aorta will eventually cause tricuspid valve obstruction or right ventricular outflow obstruction. Furthermore, 3D observation from the right ventricle elucidates the proximity of the VSD to the aorta, pulmonary artery, and tricuspid valve preparing the surgeon for potential right ventricular outflow tract obstruction after a baffle procedure and the need for a right ventricle to pulmonary artery conduit.

Left Ventricular-RA Communication Left ventricular-RA communication is often congenital in nature, however this defect can also be acquired secondary to endocarditis, mitral or aortic valve replacement, chest trauma, or myocardial infarction.74 Hansalia et al. described a patient with acquired left ventricular-RA communication related to a previous aortic valve replacement that was erroneously diagnosed

1780


A

B

C

D

E

Figs 74.59A to E: Isolated Ebstein’s anomaly. (A to C) Shows tethering of all three TV leaflets. The resulting “bubbles” are denoted by arrowheads for the septal (yellow) and posterior (black) TV leaflets and an arrow for the anterior (a) TV leaflet; (D) A threedimensional view from a child showing the large atrialized portion of the right ventricle (RV); (E) Short-axis three-dimensional view from the same child shows a large region of noncoaptation (arrow) of the tricuspid valve when viewed en-face from RV apex. (A: Anterior tricuspid valve leaflet; LA: Left atrium; LV: Left ventricle; RA: Right atrium; S: Septal leaflet of tricuspid valve. AV: Aortic valve; LV: Left ventricle; RV: Right ventricle; P: Posterior tricuspid valve leaflet). (Movie clips 74.59D and E). Source: Reproduced with permission from Patel V, Nanda NC, Rajdev S, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of Ebstein’s Anomaly. Echocardiography. 2005;22:847–54.


1781

Fig. 74.60: Real time, two-dimensional transesophageal echocardiography. Arrowhead points to a linear structure in the right atrium (RA) consistent with a Eustachian valve. Movie clip 74.60, Part 2, arrow shows the tumor. [Movie clip 74.60, (Parts 1 and 2)]. Source: Reproduced with permission from Pothineni KR, Nanda NC, Burri MV, Singh A, Panwar SR, Gandhari S. Live/real time three-dimensional transthoracic echocardiographic visualization of Chiari Network. Echocardiography. 2007;24:995–7.

A

C

B

Figs 74.61A to C: Live/real time, three-dimensional transthoracic echocardiography. (A and B) Chiari network. Small arrowheads in A point to some of the multiple openings in the large membrane, outlined by red dots. Attachment of the Chiari membrane (arrowhead) to the interatrial septum (*) is shown in (B). Movie clip 74.61A arrowhead points to the Chiari membrane; (C) Renal cell carcinoma. Arrow points to the tumor in the inferior vena cava (IVC) at the right atrial (RA) junction. (L: Liver; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; TV: Tricuspid valve). (Movie clips 74.61A and B). Source: Reproduced with permission from Pothineni KR, Nanda NC, Burri MV, Singh A, Panwar SR, Gandhari S. Live/real time three-dimensional transthoracic echocardiographic visualization of Chiari Network. Echocardiography. 2007;24:995–7.

1782


as pulmonary hypertension by 2D TTE.74 The diagnosis was likely missed by 2D TTE because of the limited views it offered, preventing complete visualization of the defect. The diagnosis in this case was also complicated by simultaneous severe tricuspid regurgitation. Follow-up imaging with 3D and its volumetric data demonstrated the defect and shunting of blood from the left ventricle to the right atrium.

Right Coronary Artery Fistula A coronary artery fistula is a rare congenital abnormality that empties blood into one of the cardiac chambers or into blood vessels through one or multiple fenestrations.75 These fistulas can also occur secondary to coronary

artery trauma. While coronary angiography has been the recommended imaging modality in the diagnosis of coronary artery fistula, it is limited in its ability to delineate intricate coronary anatomy and its proximity to other relevant structures. 2D TEE has been shown to demonstrate a fistula between the right atrium and right coronary artery with the use of color Doppler, however, it has difficulty visualizing the fistula tract in its entirety and therefore, often miscalculates its dimensions. On the other hand, 3D TEE is capable of obtaining an en face view of the right coronary artery to right atrium fistula and has been able to track the fistula along its course (Fig. 74.63). Importantly, 3D TEE was able to clearly identify the origin and termination sites of the fistula and therefore make accurate measurements, which can be used to plan for treatment.75

Fig. 74.62: Double outlet right ventricle (DORV). This subcostal three-dimensional 3 D acquisition in a child shows the relationship of the aorta (AO, right) and pulmonary artery (PA, left). Both arise from the right ventricle (RV) and the ventricular septal defect (arrow) can be extended to the aorta. (LV: Left ventricle). (Movie clip 74.62).

A Figs 74.63A and B

B


C

D

E

F

1783

Figs 74.63A to F: Live/real time, three-dimensional transesophageal echocardiography of right coronary artery to right atrium fistula. (A) Qlab study. Top arrows and the bottom right arrow point to the origin of the dilated RCA. The RCA opening viewed en face (arrow in bottom left panel) measured 1.70 cm × 1.55 cm, area 1.96 cm2; (B) Vertical arrowhead shows the continuity of the descending and the ascending (transverse arrowhead) limbs of the fistula. Arrow shows origin of the dilated RCA; (C) Qlab cropping also shows the continuity (lower arrowhead) of the descending and ascending (upper right arrowhead) limbs of the fistula. Arrow in upper left and lower right panels show the origin of dilated RCA; (D) The arrow shows flow signals moving from the fistula (arrowheads) into RA; (E and F) Represent regular (E) and Qlab (F) en face views (arrow) of the opening of fistula into RA. This measured 1.83 cm × 1.43 cm, area 3.94 cm2. Arrowheads show segments of the fistula. (AO: Aorta; AV: Aortic valve; RA: Right atrium). (Movie clips 74.63B to 74.63F). Source: Reproduced with permission from Mishra J, Puri HP, Hsiung MC, et al. Incremental value of live/real time three-dimensional over two-dimensional transesophageal echocardiography in the evaluation of right coronary artery fistula. Echocardiography. 2011;28: 805–8.

1784


SINUS OF VALSALVA ANEURYSM A sinus of Valsalva aneurysm is an unusual cardiac anomaly that can be congenital or acquired and often involves the right coronary sinus.76 Patients with sinus of Valsalva aneurysm are frequently asymptomatic, therefore, the diagnosis is either made incidentally on imaging or if the aneurysm ruptures. 2D TEE has value in identifying a sinus of Valsalva aneurysm, but has limitations in the diagnosis of a rupture. Color Doppler can be helpful in this situation, however, in the setting of hypovolemic shock after a rupture, the findings are often limited. 3D TEE incorporates multiple geometric planes and various angulations with cropping of images to localize a sinus of Valsalva aneurysm and its exact site of rupture which may not be evident on 2D TEE (Figs 74.64 and 74.65). Due to the severity of a ruptured aneurysm, urgent identification and intervention must take place providing 3D TTE with diagnostic utility.

Ventricular Septal Aneurysm Causing Right Ventricular Outflow Obstruction

obstruction referred for surgical intervention.77 Using 3D reconstruction capabilities, the ventricular septal aneurysm, the right ventricular outflow tract, and the pulmonary valve could be seen en face (Figs 74.66 and 74.67). With the shortaxis view, the aneurysm could be visualized extending almost throughout the entire right ventricular outflow tract near the level of the pulmonary valve during systole consistent with severe obstruction, a feature 2D TEE was unable to perform. 2D TEE located the VSD, but calculations made by continuous-wave Doppler were indicative of less severe outflow obstruction likely related to the intricacy of lining up the Doppler wave in the appropriate direction along the right ventricular outflow tract.

Hypoplastic Left Heart Syndrome In this entity the left sided structures including the left ventricle, the left atrium, mitral valve, aortic valve, and the aorta are small and under developed to a varying degree. The right heart is very prominent (Fig. 74.68). These newborns need urgent surgery to maintain the systemic circulation.

CONCLUSION

Aneurysm of the ventricular septum can result in right ventricular outflow tract obstruction and represents an unusual congenital cardiovascular abnormality. Baweja et al. described a patient with a large VSD and aneurysm with suspected right ventricular outflow tract

The use of 3DE alone or along with 2D echocardiography helps to increase the confidence in the diagnosis of CHD.78,79 As technology continues to improve, 3DE has the potential to expand and impact the management and treatment of this growing patient population.

A

B

Figs 74.64A and B


C

1785

D

Figs 74.64A to D: Live/real time, three- dimensional transesophageal echocardiography in ruptured right sinus of Valsalva aneurysm. (A and B) Arrow points to site of rupture of the aneurysm (AN); (C and D) Arrow points to the mouth of the aneurysm viewed en face. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle). (Movie clips 74.64A to 74.64D). Source: Reproduced with permission from Raslan S, Nanda NC, Lloyd L, Khairnar P, Reilly SD, Homan WL. Incremental value of live/ real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of sinus of Valsalva aneurysm rupture. Echocardiography. 2011;28:1041–5.

Fig. 74.65: Autopsy in ruptured right sinus of Valsalva aneurysm. Arrow points to the rupture. (AO: Aorta, LV: Left ventricle). Source: Reproduced with permission from Raslan S, Nanda NC, Lloyd L, Khairnar P, Reilly SD, Homan WL. Incremental value of live/ real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of sinus of valsalva aneurysm rupture. Echocardiography. 2011;28:1041–5.

1786


A

B

Figs 74.66A and B: Transesophageal echocardiographic delineation of ventricular septal aneurysm producing right ventricular outflow obstruction in an adult. (A) The arrow points to the ventricular septal aneurysm bulging into right ventricular outflow tract. The ventricular septal defect is delineated by the arrowhead; (B) Color Doppler examination shows a narrow turbulent jet (black arrowheads) indicative of significant obstruction produced by the aneurysm (arrow). (AV: Aortic valve; LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; TV: Tricuspid valve). Source: Reproduced with permission from Baweja G, Nanda NC, Nekkanti R, Dod H, Ravi B, Fadel A. Three-dimensional transesophageal echocardiographic delineation of ventricular septal aneurysm producing right ventricular outflow obstruction in an adult. Echocardiography. 2004;21:95–7.

A Figs 74.67A and B

B


C

1787

D

Figs 74.67A to D: Three-dimensional transesophageal echocardiographic delineation of ventricular septal aneurysm producing ventricular outflow obstruction in the same patient as in previous figure. (A) Short-axis (en-face) view just below the level of the pulmonary valve (PV) showing the aneurysm (arrow) practically occupying the entire right ventricular outflow tract (RVO) indicative of severe obstruction; (B) Long-axis view also shows the aneurysm (arrow) bulging into the RVO; (C and D) Short-axis view of the PV (black arrow); (C) Normal opening of the PV during systole indicative of absence of any obstruction at this level; (D) The PV in closed position in diastole. VS, ventricular septum. (AV: Aortic valve; LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; TV: tricuspid valve).

Fig. 74.68: Right ventricle in hypoplastic left heart syndrome. This is a subcostal acquisition of the entire right ventricle (RV) in an infant with hypoplastic left heart syndrome (HLHS). (PA: Pulmonary artery). (Movie clip 74.68).

ACKNOWLEDGMENT We thank Dr Maximiliano German Amado Escañuela for his help.

REFERENCES 1. Hage FG, Raslan S, Dean P, et al. Real time threedimensional transthoracic echocardiography in congenital heart disease. Echocardiography. 2012; 29(2):220–31. 2. Aqel RA, Hage FG, Cogar B, et al. Transthoracic echocardiography guided procedures in the catheterization laboratory. Echocardiography. 2007;24(9):1000–7.

3. Shirali GS. Three-dimensional echocardiography in congenital heart disease. Echocardiography. 2012;29(2): 242–8. 4. De Castro S, Caselli S, Papetti F, et al. Feasibility and clinical impact of live three-dimensional echocardiography in the management of congenital heart disease. Echocardiography. 2006;23(7):553–61. 5. Salustri A, Spitaels S, McGhie J, et al. Transthoracic threedimensional echocardiography in adult patients with congenital heart disease. J Am Coll Cardiol. 1995;26(3):759–67. 6. Bharucha T, Roman KS, Anderson RH, et al. Impact of multiplanar review of three-dimensional echocardiographic data on management of congenital heart disease. Ann Thorac Surg. 2008;86(3):875–81.

1788


7. Balluz R, Liu L, Zhou X, et al. Real time three-dimensional echocardiography for quantification of ventricular volumes, mass, and function in children with congenital and acquired heart diseases. Echocardiography. 2013;30(4):472–82. 8. van der Zwaan HB, Helbing WA, Boersma E, et al. Usefulness of real time three-dimensional echocardiography to identify right ventricular dysfunction in patients with congenital heart disease. Am J Cardiol. 2010;106(6):843–50. 9. Vettukattil JJ. Three dimensional echocardiography in congenital heart disease. Heart. 2012;98(1):79–88. 10. Lang RM, Badano LP, Tsang W, et al. American Society of Echocardiography; European Association of Echocardiography. EAE/ASE recommendations for image acquisition and display using three-dimensional echocardiography. J Am Soc Echocardiogr. 2012;25(1): 3–46. 11. Soriano BD, Hoch M, Ithuralde A, et al. Matrix-array 3-dimensional echocardiographic assessment of volumes, mass, and ejection fraction in young pediatric patients with a functional single ventricle: a comparison study with cardiac magnetic resonance. Circulation. 2008;117(14): 1842–8. 12. Friedberg MK, Su Xioahong MD, Tworetzky W, et al. Validiation of 3-dimensional echocardiographic assessment of left ventricular volumes, mass, and ejection fraction in neonates and infants with congenital heart disease: a comparison study with cardiac magnetic resonance imaging. Circ Cardiovasc Imaging ;3:735–742. Moake L, Ramaciotti C. Atrial septal defect treatment options. AACN Clin Issues 2005;16:252–66. 13. Hoffman JI, Kaplan S. The incidence of congenital heart disease. J Am Coll Cardiol. 2002;39(12):1890–1900. 14. Mehmood F, Vengala S, Nanda NC, et al. Usefulness of live three-dimensional transthoracic echocardiography in the characterization of atrial septal defects in adults. Echocardiography. 2004;21(8):707–13. 15. Marx GR, Fulton DR, Pandian NG, et al. Delineation of site, relative size and dynamic geometry of atrial septal defects by real time three-dimensional echocardiography. J Am Coll Cardiol. 1995;25(2):482–90. 16. Sasaki T, Miyasaka Y, Suwa Y, et al. Real time threedimensional transesophageal echocardiographic images of platypnea-orthodeoxia due to patent foramen ovale. Echocardiography. 2013;30(4):E116–7. 17. Panwar SR, Perrien JL, Nanda NC, et al. Real time/threedimensional transthoracic echocardiographic visualization of the valve of foramen ovale. Echocardiography. 2007; 24(10):1105–7. 18. Morgan GJ, Casey F, Craig B, et al. Assessing ASDs prior to device closure using 3D echocardiography. Just pretty pictures or a useful clinical tool? Eur J Echocardiogr. 2008;9(4):478–82. 19. Magni G, Hijazi ZM, Pandian NG, et al. Two- and threedimensional transesophageal echocardiography in patient selection and assessment of atrial septal defect closure by the new DAS-Angel Wings device: initial clinical experience. Circulation. 1997;96(6):1722–8.

20. Zhang L, Xie M, Balluz R, et al. Real time three-dimensional echocardiography for evaluation of congenital heart defects: state of the art. Echocardiography. 2012;29(2): 232–41. 21. Dod HS, Reddy VK, Bhardwaj R, et al. Embolization of atrial septal occluder device into the pulmonary artery: a rare complication and usefulness of live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2009;26(6):739–41. 22. Bhaya M, Mutluer FO, Mahan E, et al. Live/real time three-dimensional transesophageal echocardiography in percutaneous closure of atrial septal defects. Echocardiography. 2013;30(3):345–53. 23. Berdat PA, Chatterjee T, Pfammatter JP, et al. Surgical management of complications after transcatheter closure of an atrial septal defect or patent foramen ovale. J Thorac Cardiovasc Surg. 2000;120(6):1034–9. 24. Sinha A, Nanda NC, Misra V, et al. Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale. Echocardiography. 2004;21(8):749–53. 25. Wei J, Hsiung MC, Tsai SK, et al. Atrial septal occluder device embolization to an iliac artery: a case highlighting the utility of three-dimensional transesophageal echocardiography during percutaneous closure. Echocardiography. 2012;29(9):1128–31. 26. Nanda NC, Ansingkar K, Espinal M, et al. Transesophageal three-dimensional echo assessment of sinus venosus atrial septal defect. Echocardiography. 1999;16(8):835–7. 27. Ootaki Y, Yamaguchi M, Yoshimura N, et al. Unroofed coronary sinus syndrome: diagnosis, classification, and surgical treatment. J Thorac Cardiovasc Surg. 2003;126(5): 1655–6. 28. Singh A, Nanda NC, Romp RL, et al. Assessment of surgically unroofed coronary sinus by live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2007;24(1):74–6. 29. Mehmood F, Miller AP, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the characterization of ventricular septal defects in adults. Echocardiography. 2006;23(5):421–7. 30. Kardon RE, Cao QL, Masani N, et al. New insights and observations in three-dimensional echocardiographic visualization of ventricular septal defects: experimental and clinical studies. Circulation. 1998;98(13):1307–14. 31. Butera G, Chessa M, Carminati M. Percutaneous closure of ventricular septal defects. State of the art. J Cardiovasc Med (Hagerstown). 2007;8(1):39–45. 32. Chen FL, Hsiung MC, Nanda N, et al. Real time threedimensional echocardiography in assessing ventricular septal defects: an echocardiographic-surgical correlative study. Echocardiography. 2006;23(7):562–8. 33. Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006;23(7):598–608.


34. Singh P, Mehta A, Nanda NC. Live/real time threedimensional transthoracic echocardiographic findings in an adult with complete atrioventricular septal defect. Echocardiography. 2010;27(1):87–90. 35. Van den Boscha AE, Van Dijka VF, McGhiea JS, et al. Real time transthoracic three-dimensional echocardiography provides additional information of left-sided AV valve morphology after AVSD repair International. J Cardiol. 2006;106:360–4. 36. Kaza E, Marx GR, Kaza AK, et al. Changes in left atrioventricular valve geometry after surgical repair of complete atrioventricular canal. J Thorac Cardiovasc Surg. 2012;143(5):1117–1124. 37. Miller AP, Nanda NC, Aaluri S, et al. Three-dimensional transesophageal echocardiographic demonstration of anatomical defects in AV septal defect patients presenting for reoperation. Echocardiography. 2003;20(1):105–9. 38. Baweja G, Nanda NC, Kirklin JK. Definitive diagnosis of cor triatriatum with common atrium by threedimensional transesophageal echocardiography in an adult. Echocardiography. 2004;21(3):303–6. 39. Apitz C, Kaulitz R, Sieverding L, et al. [Echocardiographic diagnosis of the aorto-pulmonary window]. Ultraschall Med. 2007;28(2):189–94. 40. Singh A, Mehmood F, Romp RL, et al. Live/Real time threedimensional transthoracic echocardiographic assessment of aortopulmonary window. Echocardiography. 2008;25 (1):96–9. 41. Campbell M. Natural history of persistent ductus arteriosus. Br Heart J. 1968;30(1):4–13. 42. Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21(5):443–8. 43. Warnes CA. Transposition of the great arteries. Circulation. 2006;114(24):2699–709. 44. Enar S, Singh P, Douglas C, et al. Live/real time threedimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26(9):1095–104. 45. Skinner J, Hornung T, Rumball E. Transposition of the great arteries: from fetus to adult. Heart. 2008;94(9):1227–35. 46. Nanda NC, Hsiung MC, Miller AP, et al. Live/Real Time 3D Echocardiography. Chichester, West Sussex: WileyBlackwell, 2010. 47. Ahmed S, Nekkanti R, Nanda NC, et al. Three-dimensional transesophageal echocardiographic demonstration of intraatrial baffle obstruction. Echocardiography. 2003;20 (7):683–6. 48. Ho KW, Tan RS, Wong KY, et al. Late complications following tetralogy of Fallot repair: the need for long-term follow-up. Ann Acad Med Singap. 2007;36(11):947–53. 49. Pothineni KR, Wells BJ, Hsiung MC, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of pulmonary regurgitation. Echocardiography. 2008; 25(8):911–7. 50. Patel S. Normal and anomalous anatomy of the coronary arteries. Semin Roentgenol. 2008;43(2):100–112.

1789

51. Nanda NC, Bhambore MM, Jindal A, et al. Transesophageal three-dimensional echocardiographic assessment of anomalous coronary arteries. Echocardiography. 2000; 17(1):53–60. 52. Vengala S, Nanda NC, Agrawal G, et al. Live threedimensional transthoracic echocardiographic assessment of coronary arteries. Echocardiography. 2003;20(8):751–4. 53. Ilgenli TF, Nanda NC, Sinha A, et al. Live three-dimensional transthoracic echocardiographic assessment of anomalous origin of left coronary artery from the pulmonary artery. Echocardiography. 2004;21(6):559–62. 54. Mehta D, Nanda NC, Vengala S, et al. Live three-dimensional transthoracic echocardiographic demonstration of coronary artery to pulmonary artery fistula. Am J Geriatr Cardiol. 2005;14(1):42–4. 55. Friedman T, Mani A, Elefteriades JA. Bicuspid aortic valve: clinical approach and scientific review of a common clinical entity. Expert Rev Cardiovasc Ther. 2008;6(2):235–48. 56. Singh P, Dutta R, Nanda NC. Live/real time threedimensional transthoracic echocardiographic assessment of bicuspid aortic valve morphology. Echocardiography. 2009;26(4):478–80. 57. Burri MV, Nanda NC, Singh A, et al. Live/real time threedimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007; 24(6):653–5. 58. Aboulhosn J, Child JS. Left ventricular outflow obstruction: subaortic stenosis, bicuspid aortic valve, supravalvar aortic stenosis, and coarctation of the aorta. Circulation. 2006;114(22):2412–22. 59. Agrawal GG, Nanda NC, Htay T, et al. Live three-dimensional transthoracic echocardiographic identification of discrete subaortic membranous stenosis. Echocardiography. 2003; 20(7):617–9. 60. Bandarupalli N, Faulkner M, Nanda NC, et al. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008; 25(9):1004–6. 61. Rogers L, Li J, Liu L, et al. Advances in fetal echocardiography: early imaging, three/four dimensional imaging, and role of fetal echocardiography in guiding early postnatal management of congenital heart disease. Echocardiography. 2013;30(4):428–38. 62. Hlavacek A, Lucas J, Baker H, et al. Feasibility and utility of three-dimensional color flow echocardiography of the aortic arch: The “echocardiographic angiogram.” Echocardiography. 2006;23(10):860–4. 63. Scohy TV, du Plessis F, McGhie J, et al. Rapid method for intraoperative assessment of aortic coarctation using three-dimensional echocardiography. Eur J Echocardiogr. 2009;10(8):922–5. 64. Sadat K, Pradhan M, Nanda NC, et al. Two- and threedimensional transthoracic echocardiography in the assessment of aortic arch vasum vasi to pulmonary artery fistula. Echocardiography. 2013;30(2):219–24.

1790


65. Patel V, Nanda NC, Arellano I, et al. Cor triatriatum sinister: assessment by live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2006; 23(9):801–2. 66. Samal AK, Nanda NC, Thakur AC, et al. Three-Dimensional Echocardiographic Reconstruction of Atrial Membranes. Echocardiography. 1998;15(6):605–10. 67. Sinha A, Kasliwal RR, Nanda NC, et al. Live threedimensional transthoracic echocardiographic assessment of isolated cleft mitral valve. Echocardiography. 2004; 21(7):657–61. 68. Smallhorn JF. Cross-sectional echocardiographic assessment of atrioventricular septal defect: basic morphology and preoperative risk factors. Echocardiography. 2001; 18(5):415–32. 69. Ahmed S, Nanda NC, Nekkanti R, et al. Transesophageal three-dimensional echocardiographic demonstration of Ebstein’s anomaly. Echocardiography. 2003; 20(3): 305–7. 70. Patel V, Nanda NC, Rajdev S, et al. Live/real time threedimensional transthoracic echocardiographic assessment of Ebstein’s anomaly. Echocardiography. 2005;22(10): 847–54. 71. Pothineni KR, Nanda NC, Burri MV, et al. Live/real time three-dimensional transthoracic echocardiographic visualization of Chiari network. Echocardiography. 2007; 24(9):995–7. 72. Walters HL 3rd, Mavroudis C, Tchervenkov CI, et al. Congenital Heart Surgery Nomenclature and Database Project: double outlet right ventricle. Ann Thorac Surg. 2000;69(4 Suppl):S249–63.

73. Pushparajah K, Barlow A, Tran VH, et al. A systematic three-dimensional echocardiographic approach to assist surgical planning in double outlet right ventricle. Echocardiography. 2013;30(2):234–38. 74. Hansalia S, Manda J, Pothineni KR, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in diagnosing acquired left ventricularright atrial communication misdiagnosed as severe pulmonary hypertension by two-dimensional transthoracic echocardiography. Echocardiography. 2009;26(2):224–7. 75. Mishra J, Puri HP, Hsiung MC, et al. Incremental value of live/real time three-dimensional over two-dimensional transesophageal echocardiography in the evaluation of right coronary artery fistula. Echocardiography. 2011;28(7): 805–8. 76. Raslan S, Nanda NC, Lloyd L, et al. Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of sinus of valsalva aneurysm rupture. Echocardiography. 2011;28(8):918–20. 77. Baweja G, Nanda NC, Nekkanti R, et al. Three-dimensional transesophageal echocardiographic delineation of ventricular septal aneurysm producing right ventricular outflow obstruction in an adult. Echocardiography. 2004; 21(1):95–7. 78. Marx GR, Sherwood MC. Three-dimensional echocardiography in congenital heart disease: a continuum of unfulfilled promises? No. A presently clinically applicable technology with an important future? Yes. Pediatr Cardiol. 2002;23(3):266–85. 79. Marx GR, Su X. Three-dimensional echocardiography in congenital heart disease. Cardiol Clin. 2007;25(2):357–65.

CHAPTER 75 Echocardiography in the Evaluation of Adults with Congenital Heart Disease Reema Chugh

Snapshot  Key Concepts of Echocardiography in Adults with Congenital Heart Disease  Simple Congenital Heart Defects in Adults

 Valvular Disease  Complex Congenital Heart Defects

Most of the fundamental ideas of science are essentially simple, and may, as a rule, be expressed in a language comprehensible to everyone. Albert Einstein

INTRODUCTION Advancements in pediatric, medical care, surgical, and interventional techniques have improved survival into adulthood for over 85% of those born with congenital heart defects (CHDs) in developed countries. Depending upon the type of defect, presenting symptoms, and the availability of medical resources, many are diagnosed in infancy and childhood, while in others, the diagnosis is not made until adulthood. Transthoracic echocardiography is the primary diagnostic imaging test, while other modalities such as cardiac catheterization, magnetic resonance imaging (MRI), or computed tomographic angiography (CTA) are used as confirmatory or complementary tests for complete assessment and evaluation of extracardiac structures in adults with congenital heart disease (ACHD). While coronary angiography remains the gold standard for assessment of coronary artery disease, MRI is the reference standard for quantification of the right ventricular volume

and function. Adults with devices that are not MRI compatible may undergo CTA at the expense of exposure to radiation. This chapter is specifically written for an adult cardiologist and may appear very basic to a pediatric cardiologist. However, the knowledge of residua and sequelae resulting from long-term survivorship of our patients into adulthood, who are trending into geriatric years may be beneficial to all, since both pediatric and adult cardiologists are vested in favorable outcomes for all our patients. While two-dimensional (2D) echocardiogram with Doppler and color flow imaging are an essential part of routine diagnostic assessment, threedimensional (3D) echocardiography adds more details. Transesophageal echocardiography (TEE) aids in viewing posterior structures, interatrial septum, pulmonary veins, pulmonary artery, and the aorta. Intraoperative TEE helps in directing and confirming the results of the surgery. A concise and adapted version of the American

1792


Society of Echocardiography guidelines for performance of transthoracic and transesophageal echocardiography applicable to ACHD are listed in Tables 75.1 and 75.2, respectively.1,2 Exercise stress echocardiography assesses functional capacity, systemic ventricular contractile reserve, the impact of exercise on pulmonary hypertension, severity of valve diseases, and arrhythmias. All adults with CHD need routine lifelong followup for early identification of problems. Many will need reoperations and interventions due to residual shunts, prosthetic valve dysfunction, conduit stenosis, baffle leaks, or may require heart transplantation. Common clinical issues faced by these individuals are impaired left ventricular function resulting in heart failure, pulmonary hypertension, progression of valvular disease (regurgitation and stenosis), bradyarrhythmias/tachyarrhythmias (atrial and ventricular), endocarditis, aortic/pulmonary artery dilatation/aneurysms, shunt problems, and conduit failures. It is essential to make every effort to acquire prior medical records, especially the operative notes and results of previous imaging studies in order to understand each individual’s unique anatomy and gauge follow-up. In addition, women with CHD in their reproductive years need echocardiography to aid in preconception counseling, assessment of underlying defects to determine the maternal–fetal risk, guide follow-up during pregnancy, labor, delivery, and postpartum. An echocardiographer also holds the responsibility of identifying lesions that may need medical management, Table 75.1: Indications for Performing Transthoracic Echocardiography (TTE) for Adults with Congenital Heart Diseases (ACHD)

interventional procedures, or surgeries in a manner. The American College of Cardiology American Heart Association (AHA) guidelines management of adults with congenital heart

timely (ACC)/ for the disease

Table 75.2: Indications for Performing Transesophageal Echocardiography (TEE) for Adults with Congenital Heart Diseases (ACHD)

Diagnostic indications • Identification of defects in adults with poor acoustic transthoracic windows • Identification of defects that have limited visibility on TTE (such as a sinus venosus defect, fenestrated ASD, origin of the coronaries) • Rule out cardioembolic source in an adult with stroke, including assessment of possible right-to-left shunt due to a PFO with an agitated saline contrast study; examination of the left atrial appendage for a thrombus, atherosclerotic plaques in the proximal aorta • Examination of intra- or extracardiac baffles following the Fontan, Senning, or Mustard procedure • Evaluation of vegetation, perforation, endarteritis, or suspected abscess • Ruling out an intracardiac thrombus prior to cardioversion for atrial flutter/fibrillation • Status of prosthetic valves Guiding catheter-based interventions • Directing placement of ASD or VSD occlusion devices— accurate assessment of size, shape, location of the defect, and identifying associated defects • Delineation of structures not clearly visible on transthoracic echocardiography (such as pulmonary veins) • Catheter tip placement for dilation and stent implantantion for conduit/baffle stenoses in catheterization laboratory

Initial evaluation in an adult suspected of having CHD

• Guidance during radiofrequency ablation procedures

Follow-up of ACHD when there is a change in clinical status or cardiac examination

Perioperative indications

Re-evaluation to guide therapy in adults diagnosed with CHD Routine surveillance (<1 year) of adults with CHD following incomplete or palliative repair with residual structural or hemodynamic abnormality but without a change in clinical status or cardiac examination Routine surveillance (<2 years) of adults with stable CHD following complete repair, without a change in clinical status/ examination, hemodynamic abnormality, or known residual structural defects. Source: Adapted from 2011 American Society of Echocardiography guidelines for appropriate use criteria for echocardiography.1 (Free download of the detailed document is available at: http://www.asecho.org/files/AUCEcho.pdf )

• Immediate preoperative definition of cardiac anatomy and function • Assessment of postoperative myocardial function • Rule out postoperative surgical results, residual shunts, or valvular regurgitation • Assessment of the results of a minimally invasive surgical incision or a video-assisted cardiac procedure • Evaluation and monitoring of a postoperative patient with an open sternum or poor acoustic windows Source: Adapted from American Society of Echocardiography 2005 guidelines for ASE Indications and Guidelines for Performance of Transesophageal Echocardiography in the Patient with Pediatric Acquired or Congenital Heart Disease2 (Free download available: http://www.asefiles.org/pediatrictee.pdf)

Chapter 75: Echocardiography in the Evaluation of Adults with Congenital Heart Disease

determined Class I recommendations, for which there are sufficient data to clearly support the benefits of interventions/surgeries over the potential risks.3 On the other hand, with the Class III recommendations, the risks outweigh the benefits and the treatment or procedure should not be performed because it may even be harmful. The Class IIa and IIb recommendations lie in a “gray zone” where limited benefits outweigh the risks, making the treatment/procedures reasonable on an individual basis. In this chapter, the Class I and III recommendations identifiable by echocardiography are discussed, allowing the echocardiographer to play an active role in appropriate management of this population.

KEY CONCEPTS OF ECHOCARDIOGRAPHY IN ADULTS WITH CONGENITAL HEART DISEASE A Simplified Segmental Approach Unlike echocardiography in infants and children, the echocardiographic windows are far more limited in adults, primarily due to body habitus and rib spacing. In addition, adult cardiologists have a different approach to diagnosis

1793

and management of structural heart diseases. They are also not entrenched in the numerous classification systems or detailed embryological understanding of congenital heart defects. Often the terminology, vocabulary words, and terms are unfamiliar and baffling. This can make echocardiography in ACHD for the adult cardiologist quite overwhelming and intimidating. Table 75.3 lists some of the commonly used terms and Table 75.4 lists some names of the common surgeries for CHD. There is a shift from a wide spectrum of defects ranging from the “undiagnosed simple to complex” in children versus “simple undiagnosed defects to previously diagnosed/operated defects” with residua and sequelae in adults. Traditionally, most centers perform adult echocardiograms with the orientation of the images “upside down” unlike the images seen in conventional pediatric echocardiography. A basic, practical, and yet systematic approach is, therefore, necessary to allow an adult cardiologist to assess this population with clarity, accuracy, and confidence. As pointed out by Dr John Child, guru of echocardiography in adults with CHD, “Always perform a complete examination!” This step-bystep approach entails the following.

Table 75.3: Common Terminology in Adult Congenital Heart Disease (ACHD)

Atrioventricular (AV) concordance—right atrium empties into the right ventricle, left atrium empties into the left ventricle Atrioventricular (AV) discordance—right atrium empties into the left ventricle, left atrium empties into the right ventricle Dextrocardia—apex of the heart points to the right (old term dextroversion)—failure of pivoting of the cardiac apex to the left Levocardia—apex of the heart points to the left Mesocardia—apex of the heart points to the middle Dextroposition—displacement of the heart in the right chest due to a space occupying structure Eisenmenger physiology—development of irreversible pulmonary hypertension with equalization of pulmonary and systemic pressures, with pulmonary vascular resistance exceeding systemic vascular resistance leading to flow reversal (right to left) through an intracardiac shunt Right isomerism—bilateral right handedness (two morphological right atria), asplenia, both the aorta (anterior) and inferior vena cava (posterior) are on the same side of the spine Left isomerism—bilateral left handedness (two morphological left atria), polysplenia, both the aorta (posterior) and inferior vena cava (anterior) are on the same side of the spine Situs inversus totalis—heart is located in the mirror-image position of normal Ventriculoarterial concordance—the morphological right ventricle pumps into the pulmonary artery, while the morphological left ventricle pumps into the aorta Ventriculoarterial discordance—the morphological right ventricle pumps into the aorta, while the morphological left ventricle pumps into the pulmonary artery (transposition of the great arteries) Restrictive VSD—usually small in size with a left-to-right shunt without causing significant hemodynamic derangement Nonrestrictive VSD—large VSD at risk for reversal of the shunt (right-to-left). Hemodynamically, the pulmonary arterial and aortic pressures are equal so the magnitude and direction of the shunt is determined by the pulmonary vascular resistance (PVR).

1794


Table 75.4: Common Surgical Terms in Adult Congenital Heart Disease (ACHD)

Classic Blalock–Taussig–Thomas shunt—subclavian to pulmonary artery anastomosis to increase pulmonary blood flow Modified Blalock–Taussig–Thomas shunt—subclavian to pulmonary artery anastomosis, using a Gore-tex graft, to increase pulmonary blood flow Potts shunt—descending aorta to left pulmonary artery anastomosis to increase pulmonary blood flow Glenn shunt—superior vena cava to right pulmonary artery anastomosis to provide low pressure pulmonary blood flow Atrial switch repairs—in both types of atrial switch repairs, the deoxygenated blood from the vena cavae goes through a baffle into the left ventricle, which pumps the blood into the pulmonary artery. The oxygenated blood returning from the lungs passes through the pulmonary veins via another baffle into the right ventricle that pumps the blood through the aorta into the systemic circulation. Thus, the morphological right ventricle becomes a systemic ventricle and the morphological left ventricle, a subpulmonic ventricle. • Senning atrial switch repair for DTGA—baffles are created from the patient’s tissues (right atrial wall and part of the atrial septum) • Mustard atrial switch repair for DTGA—baffles are created from the pericardium and synthetic material Waterston shunt—ascending aorta to right pulmonary artery anastomosis to increase pulmonary blood flow Rastelli procedure—right ventricle-to-pulmonary artery conduit to allow blood flow from the right ventricle to reach the branch pulmonary arteries, usually in patients with right ventricular outflow tract obstruction Rashkind procedure—catheter-based procedure for balloon atrial septostomy to allow intermixing of the deoxygenated right atrial blood with the oxygenated left atrial blood in DTGA Fontan (classic)—right atrial to pulmonary artery anastomosis in tricuspid atresia Jatene—arterial switch for DTGA (anatomical correction with reimplantation of the coronaries) Biventricular repair—operation to establish two functioning ventricles without the mixing of the venous and systemic circulations, by closing the shunt defects and creating a connection between the right ventricle and the pulmonary circulation. Usually performed for tetralogy of Fallot, pulmonary atresia with VSD, transposition of the great arteries, and double-outlet ventricles.

Position of the Apex The position of the apex can be determined from the standard subcostal views. In dextrocardia, the apex points to the right, while in levocardia it points to the left. The middle position is described as mesocardia. Congenitally corrected transposition of the great arteries (CCTGAs) should be considered in the presence of dextrocardia, especially when the gastric bubble is on the left and the cardiac apex is on the right.

Determination of Atrial Situs In atrial situs solitus, the morphological right atrium is located on the right side and the morphological left atrium is located on the left side. The most specific identifying feature of the right atrium is the eustachian valve (Fig. 75.1). In the subcostal views or the apical four-chamber views (with posteriorly tilted probe), it can often be traced from the orifice of the inferior vena cava, across the floor, to the lower portion of the atrial septum. The right atrium can usually be identified by the drainage of the inferior vena cava except in situs ambiguous (isomerism). The superior vena caval drainage is not as predictable, since

Fig. 75.1: Transthoracic echocardiogram (apical four-chamber view) showing an echodensity in the right atrium due to the remanent of a eustachian valve. (EV: Eustachian valve; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

it can drain into either atria or into both as in the case of persistent left superior vena cava. The left atrium usually has pulmonary veins draining into it, other than in the case of an anomalous pulmonary venous drainage. In situs inversus, this relationship is reversed.


1795

Determination of Atrioventricular Relationship (the Location of Ventricles by Bulboventricular Loop) In the D-loop, the right ventricle is on the right while the left ventricle is on the left. In the L-loop, there is ventricular inversion with the morphological right ventricle on the left and the morphological left ventricle on the right side. Since the atrioventricular (AV) valves always follow their respective ventricles, the tricuspid valve is attached to the morphological right ventricle and the mitral valve is attached to the morphological left ventricle. Accordingly, the positions of the tricuspid and mitral valves are also transposed in the L-loop. Other identifying features of the AV valves are their positions and morphology. In the apical four-chamber view, the position of the trileaflet tricuspid valve is closer to the apex as compared with the mitral valve. In the parasternal short-axis view, the mitral valve is shaped like a “fish mouth” and has chordal attachments to the two papillary muscles. The crescent-shaped right ventricle is heavily trabeculated as compared with the ellipsoid left ventricle. The left ventricle usually has a smooth endocardial border except in adults with left ventricular noncompaction or in those with long-standing hypertension. In the right ventricle, the presence of a moderator band (a prominent muscle bundle crossing from the septum to the free wall), and septal attachment of the tricuspid valve positioned more apically that the mitral valve (since the AV valves are always attached to their respective ventricles) provides further confirmatory evidence.

Ventriculoarterial (VA) Connections In a normal/concordant connection, the right ventricle pumps into the pulmonary artery while the left ventricle pumps into the aorta, with the position of the aorta being posterior and to the right of the pulmonary valve. In transposition of the great arteries/discordant VA connection, the morphological right ventricle pumps into the aorta while the morphological left ventricle pumps into the pulmonary artery. The pulmonary artery is identified by its right and left branches in the high parasternal shortaxis view. The aorta is identified by its “candy cane” or “hockey-stick” appearance in the suprasternal views. The cranial branches (brachiocephalic, common carotid, and subclavian) may also be delineated in this view (Fig. 75.2). The origin of the coronary arteries may be seen in the high

Fig. 75.2: Diagrammatic representation of the aortic arch (AoA) in the suprasternal view, displaying the branches. (BC: Brachiocephalic; C: Carotid; SC: Subclavian).

parasternal short-axis view. The aortic and pulmonary valves remain loyal to their respective great arteries.

Abdominal Situs Abdominal situs is usually concordant with atrial situs. Hence, it is often used to determine the atrial situs, although the two follow each other around 70% of the time. In atrial situs solitus, this relationship can be revealed in the subcostal views by tracing the path of the inferior vena cava, which is nonpulsatile (blue on color Doppler) and located on the right of the spine as it passes through the liver. The descending thoracic aorta is pulsatile (red on color Doppler) and courses on the left of the spine. Gastric folds and stomach bubble are also seen on the left side. However, in atrial situs inversus, all these positions are reversed with aorta to the right of the spine and the inferior vena cava to the left of the spine. The subcostal view also allows determination of direction along which the major axis of the heart is aligned.

Assessment of the Shunts Adults with CHD may have congenital shunt defects or surgically created shunts for palliative repairs. In addition, patch leaks or suture dehiscence cause iatrogenic shunt lesions. While color Doppler is the initial method of choice to detect a shunt, pulsed wave and continuous wave Doppler allow evaluation of the gradient across the shunt.

1796


An agitated saline contrast study, popularly referred to as the “bubble study,” is useful for the right heart lesions. On the other hand, contrast echocardiography using a defined agent that lasts long enough to make its way to the left heart allows further delineation of both right and left defects. An agitated saline contrast study can be performed by promptly injecting 10 mL of agitated saline contrast (8 mL of saline mixed with 1 mL of blood and 1 mL of air) through a peripheral intravenous catheter. Its accuracy in detecting a right-to-left shunt increases significantly by performing an adequate Valsalva maneuver. The images are recorded for 5 to 12 beats to assess for an intracardiac shunt (with prompt appearance of microbubbles) versus a pulmonary arteriopulmonary shunt (with delayed appearance of microbubbles).4,5 It should be avoided in patients with a large intracardiac shunt because of the risk of cerebral microemboli. Contrast echocardiography using the perflutren lipid microsphere injectable suspension should not be used in adults with suspected right-to-left, bidirectional, or transient right-to-left cardiac shunts. Based on the manufacturers approved protocol, it may be used in those without shunts to opacify the left ventricular chamber for better visualization of endocardial borders when echocardiograms are suboptimal. It has also been useful in defining intracardiac masses, diagnosing left ventricular noncompaction, left ventricular aneurysm/rupture, and aortic pathologies including dissection.6 In most adults with major shunt defects, like the atrial/ ventricular septal defects or patent ductus arteriosus, chamber enlargement serves as a valuable surrogate for gauging the impact of a long-standing shunt on the receiving chambers. The right heart is enlarged in atrial septal defects, while the left heart is enlarged in ventricular septal defects and patent ductus arteriosus due to increased pulmonary blood flow directed eventually to the left heart. A shunt volume calculation based on information derived from a TTE and TEE plays a limited role for more accurate assessment of pulmonary to systemic flow (Qp/Qs) in some adults.

Echocardiography in Pregnancy The hemodynamic and physiological effects of pregnancy in women with CHD pose an extra workload on the cardiovascular system. As the pregnancy progresses into the second and third trimesters, there is a 30% to 40% increase in blood volume causing an 18% to 25% increase in stroke volume. The heart rate rises by 20% and the

combined effect results in a 30% to 50% increase in cardiac output. The pulmonary as well as the systemic vascular resistances fall, leading to a mild drop in both the systolic and diastolic blood pressures.7 An echocardiogram during pregnancy also reflects these changes.8,9 During the second trimester, there is increase in sizes of the left and right ventricles and the left atrium. There is expansion of the left ventricular (LV) volume in systole and diastole. There is hypertrophy of the left ventricular walls. By the third trimester, the heart appears more globular. Biventricular reductions in global and segmental longitudinal deformations have been noted as compensatory changes to accommodate the increase in cardiac dimensions during pregnancy. Ejection fraction does not change in women with anatomically normal hearts. However, in women with CHD, the systemic and pulmonic ventricular size and function should be followed up during pregnancy and in postpartum, since a change is likely to occur in those with marginal contractile reserves. In addition, evaluation of residual or recurrent lesions, severity of pulmonary hypertension, and measurement of aortic root size should be performed. While stress echocardiography using treadmill exercise testing should be avoided during pregnancy, this test is very valuable before conception for assessing the baseline functional capacity, exercise duration, and workload metabolic equivalents of task (METs). Attention should be paid to exercise-induced symptoms, arrhythmias, or ischemia, since these are likely to recur with the hemodynamic stress of pregnancy. Imaging provides information about the contractile reserve with response of systemic and pulmonic ventricle to exercise. Changes in pre- and postexercise gradients across stenotic valves, left or right ventricular outflow tract gradients, and estimated right ventricular systolic pressures (RVSP) are also reflective of the potential changes during pregnancy, labor, and delivery. When strongly indicated, a submaximal treadmill stress test without exceeding 70% of the maximum agepredicted heart rate on Bruce protocol may be performed during pregnancy. Unless it is absolutely necessary, any exposure to radiation should be avoided during pregnancy. The risk of radiation exposure to the fetus should be discussed with the mother. If possible, the procedures should be postponed, until late second or third trimesters of pregnancy. Abdominal shielding for protection of the fetus is always necessary. These women need individualized preconception counseling. Maternal and fetal outcomes depend


upon the severity of underlying defects and maternal functional status prior to pregnancy. Echocardiography allows preconception assessment and follow-up during pregnancy. Other complimentary imaging modalities may need to be performed in select cases for identification and correction of hemodynamically significant underlying defects before pregnancy. Women with severe pulmonary hypertension, ascending aorta diameter > 4.5 cm, or lesions that cannot be repaired before pregnancy should be counseled to avoid pregnancy due to high maternal morbidity and mortality.10

Aortic Root in Adults with Congenital Heart Disease Structural abnormalities of the great arterial walls and additive hemodynamic stress lead to dilatation of the aorta and the pulmonary arteries in many congenital heart defects.11 Progressive dilatation has been noted with bicuspid aortic valve, coarctation of aorta, large ventricular septal defect, tetralogy of Fallot/pulmonary atresia with ventricular septal defect, and in truncus arteriosus11 (Table 75.5). Echocardiographic assessment of the aortic root dimension should be routinely performed. Roman et al described a method of measuring the aortic root at end diastole by the leading-edge convention in the parasternal or occasionally, apical long-axis view that displayed the maximum diameter parallel to the aortic annular plane. The aortic annular diameter was measured between the hinging points of the right and noncoronary cusps of the aortic valve in systole.12 Normal limits in relation to age, body size, and gender of 2D echocardiographic aortic root dimensions have been described in patients aged 15 years or older by Devereux et al.13 In absolute terms, aortic root dilatation is defined as diameter at the level of a sinus of Valsalva ≥ 4 cm.

1797

In our practice, we make all measurements after freezing the most suitable systolic frame that allows: (a) proper identification of the hinging points of the right and noncoronary cusps of the aortic valve; and (b) measurements recorded at reproducible anatomical landmarks perpendicular to the axis of blood flow. These measurements are taken at the level of the aortic annulus, midsinuses, sinotubular junction, and about 2 cm distal to the sinotubular junction as shown in a parasternal longaxis view.14 Linear measurements are then recorded from inner edge to inner edge (Fig. 75.3). It should also be noted that in radiographic imaging, aortic root measurements are made from outer edge to outer edge. Aortic aneurysms have been known to cause dissection in association with some of these defects. Operative repair is indicated in symptomatic patients with aortic diameter over 4.4 to 5 cm and/or growth >0.5 cm/year, for ascending aortic aneurysms associated with bicuspid aortic valve or other genetically mediated disorders that are at high risk for dissection, according to the clinical practice guidelines for thoracic aortic disease.15 The aortic root should be assessed annually if the diameter ranges from 3.5 to 4.4 cm and semiannually if it is 4.5 to 5.5 cm. A debate about more specific guidelines for a variety of CHDs continues.

Table 75.5: Congenital Heart Defects in Adults Commonly Associated with a Dilated Aortic Root

Bicuspid aortic valve Ventricular septal defect Coarctation of aorta Tetralogy of Fallot Truncus arteriosus Transposition of the great arteries Single ventricle (univentricular heart) with pulmonary stenosis

Fig. 75.3: Diagram showing the aortic root in the parasternal long-axis view. Measurements are taken (leading edge to leading edge) at the level of the (1) aortic annulus at the hinge points of the leaflets, (2) midsinuses, (3) sinotubular junction, and (4) about 2 cm distal to the sinotubular junction.

1798


SIMPLE CONGENITAL HEART DEFECTS IN ADULTS Shunt Lesions Patent Foramen Ovale Ruling out a cardiac source of emboli in an adult with a stroke or transient ischemic attack may be one of the most common indications for performing a TEE in most hospitals around the world. Although a TEE can visualize various causes of cerebrovascular events such as systemic ventricular/left atrial appendage thrombi, atheromatous plaques in the ascending aorta/arch, the possibility of a paradoxical embolus through a patent foramen ovale (PFO) also needs to be ruled out. Color Doppler with TTE in the subcostal view or on multiplane TEE views may alert us of its existence in many cases. An agitated saline contrast study during TTE or TEE requires an adequate Valsalva maneuver in an adult to prove a right-to-left shunt. Transcranial Dopplers are currently the reference standard for ruling out paradoxical microemboli.16,17 Three-dimensional echocardiography is more likely to demonstrate PFO as a slit-shaped tunnellike defect in the atrial septum by TTE in adults with good acoustic windows or by TEE in all the adults. Persistent patency of the foramen ovale in adults makes it the most common CHD, with an autopsy-derived incidence of around 27% for a probe patent PFO.18 TEE with saline contrast has detected the association between rightto-left shunting at rest and high membrane mobility, in patients with cerebrovascular ischemic events who have a PFO, and are at higher risk for recurrent brain embolism.19 The atrial septum (fossa ovalis membrane) may demonstrate thinning and marked redundancy. An atrial septal aneurysm (ASA) is characterized by a redundant, undulating, interatrial membrane in the region of the fossa ovalis (Fig. 75.4). The diameter of the base can exceed 15 mm and the amplitude of the interatrial septum excursion is above 10 to 15 mm. ASA may be associated with one or multiple PFOs on an average in 70% of the cases.20 Besides PFO, the ASA may be associated with mitral valve prolapse, dilated atria, and intracardiac thrombi, which may explain the increased frequency of embolic stroke in this population.21 ASA and PFO synergistically potentiate the risk for cryptogenic stroke in adults <55 years of age.20,22,23 There is an increased likelihood of thrombus formation on the left atrial side of the ASA. Other echocardiographic findings associated

Fig. 75.4: Transesophageal echocardiogram showing an atrial septal aneurysm (ASA), which can be described as a redundant, undulating, interatrial membrane in the region of the fossa ovalis. (LA: Left atrium; RA: Right atrium).

with a potentially higher risk for cerebral embolic events are eustachian valve anatomy or Chiari network favoring right-to-left shunting.24 Device closure for PFO in adults with cryptogenic stroke remains controversial. Information from two prospective clinical trials, CLOSURE I (Evaluation of the STARFlex Septal Closure System in Patients with a Stroke and/or Transient Ischemic Attack due to Presumed Paradoxical Embolism through a Patent Foramen Ovale) study25 and Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment (RESPECT)26 show that between medical management and PFO device closure, there is no significant benefit in the outcomes. These studies evaluated the incidence of recurrent ischemic strokes in the primary intention-to-treat analysis associated with closure of a PFO in adults who had a cryptogenic ischemic stroke. However, in a subset of this population, device closure was superior to medical therapy alone (in the prespecified per-protocol and as-treated analyses), with a low rate of associated risks.26 Another prospective study conducted by the PC trial investigators reports that closure of a PFO for secondary prevention of cryptogenic embolism did not result in a significant reduction in the risk of recurrent embolic events or death as compared with medical therapy.27 Currently, the decisions to “close or not to close” the PFO in young adults with cryptogenic stroke are being


made on humanitarian grounds on a case-by-case basis after weighing individual risk benefit ratio and providing an informed consent. Intracardiac echocardiography (ICE) has played a major role in device closure.28 More recently, 3D TEE has taken its place in many centers.29 However, there is a significant disagreement between TEE and rotational ICE in measuring fossa ovalis and selecting the device for PFO closure, particularly in patients with ASA.30

Atrial Septal Defects Adults with undiagnosed atrial septal defects (ASD) usually present with dyspnea, fatigue, and palpitations due to atrial arrhythmias. The various types of atrial septal defects are secundum, primum, sinus venous, and the rare coronary sinus defect.31

Echocardiography Primarily, the subcostal, followed by the high parasternal and apical four-chamber views are the best views in assessment of the atrial septum. There is a likelihood of a false-positive reading of an ASD due to midseptal dropout in the apical four-chamber view. Pulsed and color flow Doppler define the direction of the shunt most accurately at a lower Nyquist level. The direction of the low-velocity shunt depends on ventricular compliance. Other low venous flows from the superior and the inferior vena cava or the coronary sinus can cause a false-positive signal suggestive of an interatrial communication by color Doppler. A tricuspid regurgitant jet with the flow directed toward the interatrial septum can also be misleading.

A

B

1799

Right heart enlargement with diastolic flattening and paradoxical motion of the interventricular septum indicate right ventricular volume overload in the presence of a significant left-to-right shunt. On transthoracic echocardiography, right atrial/ventricular enlargement, a D-shaped septum (on the short-axis view in diastole) with paradoxical motion of the interventricular septum, and varying degrees of pulmonary hypertension occur due to long-standing left-to-right shunt. When pulmonary stenosis is present, it may prevent the development of secondary pulmonary hypertension. In the absence of pulmonary stenosis, the estimated right ventricular systolic pressure (RVSP) is a surrogate for pulmonary artery pressure. As with acquired heart disease, it is assessed by applying the simplified Bernoulli equation: RVSP = 4 (tricuspid regurgitation (TR) jet velocity)2 + right atrial pressure Right heart enlargement and dilatation of the pulmonary artery are signs of a significant shunt volume and are sufficient to warrant closure of the atrial septal defect. A Qp/Qs calculation is unnecessary in these cases. Other concomitant defects that contribute to left heart volume overload are complete atrioventricular septal defects associated with a cleft mitral valve and mitral regurgitation.

Types of Atrial Septal Defect (Figs 75.5A to C) The secundum ASD is the most common type and comprises nearly 75% of the ASDs. It is best seen in the subcostal view. It can be seen in the apical four-chamber

C

Figs 75.5A to C: Diagram showing locations of the three common types of atrial septal defects (ASD): (A) Secundum ASD; (B) Primum ASD; (C) Sinus venosus ASD. (LA: Left atrium; RA: Right atrium; RUPV: Right upper pulmonary vein; SVC: Superior vena cava).

1800


view but there may be some false-positive dropouts of the midseptum. Besides right heart enlargement that may progress to right or biventricular heart failure, these patients are at risk for paradoxical embolism, progressive pulmonary hypertension, and have an increased incidence of atrial arrhythmias. The ostium primum ASD (20%) that rarely presents as an isolated finding is best seen in the apical four-chamber view as an echo dropout in the lower part of the interatrial septum. It is usually associated with a cleft anterior mitral valve, which is best seen in the parasternal short-axis view. Its association with atrioventricular septal defect is later discussed in this chapter. The sinus venous defect (5%) is usually associated with anomalous pulmonary venous drainage and often missed on a transthoracic echocardiogram. The entire atrial septum from the orifice of the superior vena cava to the orifice of the inferior vena cava should be displayed to identify echo dropout. It is usually best seen in the subcostal short-axis view, and occurs between the junction of the superior vena cava and the interatrial septum. It rarely presents in adults as a dropout between the inferior vena cava and the interatrial septum. A rare case of coronary sinus defect (1%) is suspected especially in the presence left superior vena cava draining into the roof of the left atrium. There may be partial or complete absence of the coronary sinus. It is best seen in a modified apical four-chamber view. A large coronary sinus orifice shows evidence of left-to-right atrial shunting due to defect in the roof of the coronary sinus (sinoseptal defects). The right ventricular systolic pressure needs to be determined, since pulmonary hypertension is likely to occur in adults with significant shunts. If there is a significant right-to-left shunt due to another defect, the orifice of the coronary sinus may not be so enlarged and go unrecognized. With the development of pulmonary hypertension, the low velocity of the shunt flow across the coronary sinoseptal defect may be confused with other low-velocity flow states within the atria. Anomalous pulmonary venous drainage is more commonly associated with sinus venosus ASD but can also occur in this setting. Tricuspid atresia has also been reported with a coronary sinus defect. Common atrium is a rare condition in which the atrial septum is nearly or completely absent, causing an intermixing of the oxygenated and deoxygenated blood. The right and left sides of the common atrium retain morphological features of the right and left atria. It may

be associated with an atrioventricular septal defect, cleft mitral valve, partial anomalous pulmonary venous return, and left superior vena cava. Pulmonary hypertension may be present due to increased pulmonary arterial flow. The best views are the apical four-chamber and the subcostal views for detecting the absence of the interatrial septum, defect in the membranous ventricular septum, right heart enlargement with 2D echocardiography and color Doppler. The parasternal short-axis views at the aortic level show dilatation of the pulmonary artery due to pulmonary hypertension.

Transesophageal Echocardiography A TEE is necessary in nearly all adults for localizing/sizing the secundum ASD, measuring septal rims (superior and inferior), entry of the superior vena cava, connection of all pulmonary veins, and for ruling out concomitant defects before planning device closure or surgery. Color Doppler can determine the major direction of the shunt (Fig. 75.6). Measurements are made in orthogonal planes to allow selection for appropriate candidates for device closures. Three-dimensional TEE allows real time visualization of the defect. It also allows more defined measurements of the rims, size, and location with respect to adjacent structures, and assessment of concomitant defects. In the current era, it plays a major role in transcatheter implantation of the ASD closure device.32–36 TEE also helps in detecting procedural complications such as device embolization into the pulmonary artery or into the iliac artery.37,38 Early and late complications such as erosions caused by devices can also be demonstrated by TEE.39

Fig. 75.6: Transesophageal echocardiogram with color Doppler showing the left-to-right shunt due to a secundum atrial septal defect (ASD). (AoV: Aortic valve; RA: Right atrium).


The presence of right heart enlargement and/or mild pulmonary hypertension without a visible defect on TTE should be investigated by a TEE with the probe angled to around 90° for delineating a sinus venosus defect, and with posterior angulation of the probe to demonstrate a coronary sinus defect. TEE plays a pivotal role in assessment of the pulmonary veins.40,41 It is very useful in diagnoses of these two types of defects that are often missed by transthoracic

1801

echocardiography.42,43 A synopsis of echocardiographic assessment of ASDs is reviewed in Table 75.6.

Contrast Echocardiography An agitated saline contrast study is usually unnecessary in adults with ASDs but when performed, it may reveal a bidirectional shunt with the major component of a

Table 75.6: Atrial Septal Defects

Types • Secundum—most common type of ASD • Primum ASD—often associated with an endocardial cushion defect/partial AV canal defect (inlet VSD) and cleft anterior mitral valve • Sinus venous ASD—usually associated with partial anomalous pulmonary venous return • Coronary sinus ASD—commonly seen with persistent left superior vena cava • Common atrium Associated defects • Occurs mostly as an isolated anomaly • Partial anomalous pulmonary venous return (sinus venosus defect) May occur in association with the following defects: • Mitral valve prolapse • Ventricular septal defect • Patent ductus arteriosus • Pulmonary stenosis/right ventricular outflow tract obstruction • Tetralogy of Fallot • D-transposition of the great arteries • Congenitally corrected transposition of the great arteries • Truncus arteriosus • Tricuspid atresia • Ebstein’s anomaly Echocardiographic assessment • Identification of the type of defect • Estimation of the size of the defect in orthogonal views to get the largest dimension with 2D echocardiography or by planimetry with 3D echocardiography • Color Doppler to assess to direction of the shunt (using low Nyquist limit) • Pulsed wave Doppler—characteristic flow pattern begins in early systole, although most of the cardiac cycle with a broad peak in late systole/early diastole, with peak velocity usually < 2 m/s (combination of pulmonary and systemic venous flow) • Right heart size—right atrium and ventricle are enlarged when the shunt is significant with Qp/Qs over 1.5 (may avoid the need to calculate Qp/Qs) • Estimation of right ventricular systolic pressure/degree of pulmonary hypertension Postoperative • Rule out residual shunt • Device closure – Confirm alignment of the device along the interatrial septum – Rule out impingent on surrounding structures—mitral valve, aortic valve, and pulmonary veins—or erosion of the device

1802


left-to-right shunt. A dense bolus from an intravenous agitated saline injection shows “negative” contrast jet near the defect with passage of a few bubbles into the left atrium during transient periods of higher right atrial pressure. Contrast echocardiography is contraindicated in patients with Eisenmenger physiology, since a large bolus of microemboli entering the systemic circulation may potentially cause cerebral ischemia.

hypertension, right heart failure, and the likelihood of atrial arrhythmias. Adults with large secundum ASD/septal aneurysm, primum, sinus venosus, or coronary sinus defects need surgery for closure of the defect and repair of concomitant defects. Although adults with small ASDs (< 5 mm) are at low risk of having these complications, closure may be considered to reduce the risk of paradoxical embolism.

Exercise Testing

The Postoperative Adult

Exercise testing is useful for objective assessment of functional capacity and for revealing exercise-induced arrhythmias, and changes in oxygen saturation in adults with pulmonary arterial hypertension. Maximal exercise testing should be avoided and effort should be restricted to <70% of maximum age-predicted heart rate, in those with severe pulmonary arterial hypertension.

Following repair of all ASDs or device closure of the secundum ASD, echocardiography plays an important role in ruling out residual shunts or pulmonary hypertension. Intraoperative TEE checks the adequacy of the repair by confirming the absence of residual shunts in all types of ASDs after device or surgical repair. It is especially useful after pericardial patch repair of the sinus venosus defect in the superior vena cava, with baffle redirecting the anomalous pulmonary veins to the left atrium. Narrowing or stenosis of the superior vena cava or pulmonary veins will manifest as flow acceleration on color Doppler at the site of the obstruction. Postoperatively, an urgent TTE is necessary in a surgical patient presenting with fever, pleuritic chest pains, and progressive dyspnea with or without abdominal symptoms to rule out pericardial effusion and possible tamponade, since there is a likelihood of pericarditis for several weeks postoperatively. Device malalignment or impingement on surrounding structures (pulmonary veins, aortic, and mitral valves) should be ruled out following device closure. Other potential complications following ASD device closure are pericardial effusion, erosion of the atrial wall or aorta, device thrombosis, or endocarditis within first 6 months of implantation. TTE should be performed on the day following device closure, at 1 month, 6 months, at 1 year, and then annually for a few years post device closure.

Cardiac Catheterization Diagnostic cardiac catheterization is not indicated in younger adults with uncomplicated ASD if they have had adequate noninvasive imaging. Shunt runs are of value when the site of the defect is unclear, such as in case of sinus venosus defect or a coronary sinus defect. Cardiac catheterization is essential for assessment of pulmonary vasoreactivity in adults with severe pulmonary hypertension prior to ASD closure. In older adults, coronary artery disease also needs to be ruled out before surgical closure. Currently, cardiac catheterization is mostly performed in conjunction with device closure of an ASD.

Magnetic Resonance Imaging/Computed Tomographic Angiography MRI/CTA delineates the course of the anomalous pulmonary veins into the right atrium, persistent left superior vena cava, and allows visualization of other extracardiac structures.

Ventricular Septal Defects ASD Closure The Class I ACC/AHA recommendations for closure of an atrial septal defect are visual or quantifiable evidence of right heart overload (right heart enlargement or Qp/Qs over 1.5).3 Early closure of moderate to large defects lowers the risk of long-term complications including pulmonary

Although ventricular septal defects (VSDs) are the most common defects in infancy, they are less prevalent in adulthood due to spontaneous closure in early life. The clinical presentation of an isolated VSD through life will depend largely on defect size and pulmonary vascular resistance.31,44–47


1803

Fig. 75.7: Transthoracic echocardiogram (apical four-chamber view) showing that the tricuspid septal leaflet prolapses in an attempt to close the ventricular septal defect (VSD) leading to the development of a membranous septal aneurysm. (ASD: Atrial septal defect; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve).

Fig. 75.8: Diagrammatic representation of the “venturi effect” causing prolapse of aortic valve (AoV) cusp in an attempt to close the ventricular septal defect (VSD), leading to aortic regurgitation (AR) as seen with a transesophageal echocardiogram.

Most individuals are diagnosed in childhood due to a loud murmur. Device or surgical closure is not indicated in adults with small VSDs in the absence of pulmonary hypertension. These adults are at a higher risk of acquiring endocarditis, where the VSD jet strikes the endocardial surface close to the tricuspid valve causing tricuspid valve vegetations that may predispose to pulmonary embolism. The tricuspid septal tissue may prolapse in an attempt to close the VSD leading to the development of membranous septal aneurysm (Fig. 75.7). Large membranous septal aneurysms can also cause obstruction to the right ventricular outflow tract. Similarly, aortic regurgitation can occur when the aortic cusps (usually right or left) attempt to spontaneously close a membranous VSD due to “venturi effect”—a suction force that is created by a gradient across the VSD that draws the aortic valve leaflet to prolapse and close the VSD in a flap-like manner (Fig. 75.8). Moderate to large VSDs may present with impaired left ventricular function and heart failure. Progressive tricuspid regurgitation and increasing severity of pulmonary hypertension are also potential long-term issues. In some unfortunate cases, a large VSD may predispose to irreversible pulmonary hypertension (Eisenmenger physiology) that is no longer amenable to surgical closure. The VSDs are classified according to their position in the interventricular septum (Figs 75.9A to C). They have

also been numerically divided into four types, correlating with their position as noted below.48

Type 1: Supracristal (Also Known as Outlet, Subpulmonic, Infundibular) VSD The parasternal short-axis view is the best view to document a left-to-right shunt in the 2 o’clock position at the level of the aortic valve. It may present as a low-velocity diastolic shunt flow preceding a left-to-right shunt during systole, and can be mistaken as other defects such a sinus of Valsalva aneurysm or a coronary artery fistula, since they also similarly appear in the parasternal long-axis view.

Type 2: Membranous (or Perimembranous) VSD This is the most common type of VSD in adults and it is best seen in the parasternal long-axis and short-axis views with the help of color Doppler that reveals a turbulent left-to-right shunt. Two-Dimensional echocardiographic images may show a dropout in the membranous septum just below the aortic valve in the five-chamber view. Other suitable views for visualizing this defect are the apical and subcostal views.

1804


A

B

C

Figs 75.9A to C: Diagram showing locations of the four types of ventricular septal defects (VSD). (AoV: Aortic valve; LA: Left atrium; LV: Left ventricle; PA: Main pulmonary artery; RA: Right atrium; RV: Right ventricle).

Type 3: Inlet (or AV Canal Type) VSD This type of VSD is usually associated with a primum ASD and involves the area around the crux of the heart. It may present as an AV septal defect with associated AV valve abnormalities as seen in individuals with Down syndrome. It is best seen in the apical four-chamber view.

Type 4: Muscular These VSDs may be multiple or large enough to persist into adulthood. They are located in the trabecular septum

with a rim of muscle around the defects. They are best seen in the parasternal long-axis view or in the apical fourchamber view with the help of color Doppler.

Echocardiography Transthoracic echocardiography with color Doppler displays location, size, and number of the VSD. For calculation of pressure gradient across the VSD with continuous wave Doppler, the cursor should be aligned along the direction of the VSD for accurate assessment of the shunt. Heart chamber dimensions, presence of


right or left ventricular outflow obstruction, and left ventricular size and function should be estimated on serial echocardiograms. A significant volume of blood flow is directed from the left to the right shunt into the pulmonary artery leading to an increased left heart volume. Over time, this causes left heart enlargement and decreases left ventricular function. The aortic valve morphology and function should be evaluated to rule out prolapse and regurgitation. Estimation of right ventricular systolic pressure (RVSP) is usually performed using the pulmonary regurgitation jet, since contamination of the tricuspid jet signal by a VSD jet, through the left-to-right shunt, may overestimate RVSP. Associated defects that need to be ruled out are listed in Table 75.7.

Magnetic Resonance Imaging/ Computed Tomography These imaging modalities are useful for assessment of apical and supracristal VSDs in unusual locations, and for evaluation of extracardiac structures such as the aorta.

Cardiac Catheterization It is usually performed in conjunction with device closure of the defect. The major role of diagnostic cardiac catheterization is in assessment of pulmonary artery pressures and pulmonary vasoreactivity prior to closure, when pulmonary hypertension is suspected on echocardiography. In addition, coronary arteriography is performed in older adults prior to surgical closure of the defect.

VSD Closure The Class I ACC/AHA recommendations for closure of a VSD are the evidence of left ventricular volume overload (Qp/Qs ≥ 2.0) or a history of infective endocarditis. VSD closure is contraindicated in adults with severe irreversible pulmonary vascular disease. At other times, VSDs are closed during surgery for aortic regurgitation and other associated defects.49 Although there is no Class I indication for catheterbased device closure of a VSD in an adult, the Class IIa indications for device closure include high surgical risk with hemodynamically significant residual shunt or history of infective endocarditis. In these cases, the VSD should not be located proximal to the aorta or the tricuspid

1805

valve, because otherwise there will be device impingement on these structures. Intraoperative TEE with color Doppler allows detection of multiple VSDs, especially muscular or supracristal preoperatively, since these may not be directly visible to the surgeon. After the operation, TEE confirms patch closure and rules out residual defects. Patch closure and use of intraoperative TEE have been shown to improve surgical outcomes.49 A comprehensive assessment of concomitant defects requiring surgery, such as aortic valve repair/replacement for regurgitation, resection of subaortic membrane in case of left ventricular outflow tract obstruction, and relief of right ventricular outflow obstruction by adequate resection and patch should be performed.

The Postoperative Adult Postoperatively, TTE is useful for assessment of left ventricular function, ruling out residual shunts or pulmonary hypertension. Associated defects such as aortic root dilatation and aortic regurgitation need longterm follow-up.

Patent Ductus Arteriosus Survival into the ninth and tenth decades of life is possible in an adult with an unoperated patent ductus arteriosus (PDA). The PDA is a vascular structure that connects the inferior curvature of the proximal descending aorta to the roof of the main pulmonary artery near the origin of the left pulmonary artery in fetal life, and is designed for spontaneous closure in early infancy. Persistent ductus arteriosus may occur in adulthood when spontaneous, surgical, or device closure has failed to occur in childhood.31

Echocardiography Echocardiography is sensitive and very specific in diagnosing PDA. Tiny PDAs may sometimes be missed and there is low likelihood of a false-positive PDA.50,51 Two-dimensional TTE is able to demonstrate a persistent anatomical connection between the descending aorta and the pulmonary artery only in some adults. This is due to limited acoustic windows because of body habitus or secondary to lower ultrasonic frequencies hampering

1806


Table 75.7: Ventricular Septal Defects

Types • Perimembranous—most common • Supracristal/infundibular/subpulmonic • Muscular • Atrioventricular (AV) septal defect [inlet/atrioventricular (AV) canal defect] Associated defects • Atrial septal defect • Patent ductus arteriosus • Coarctation of aorta • Aortic root dilatation • Aortic regurgitation • Tricuspid regurgitation Echocardiographic assessment • Identification of the type of defect • 2D and color Doppler evaluation of the size of defect in systole • Color and continuous wave Doppler to determine the direction and gradient of the shunt • Is it a restrictive or nonrestrictive VSD? •

Impact on chamber size – Left atrial dilation, left ventricular dilatation (due to excess blood going through the lungs because of the left-to-right shunt) – Right heart enlargement/right ventricular hypertrophy occurs in adults with Eisenmenger physiology

• Ventricular function—left ventricular systolic function • Rule out associated defects • Examination of the aortic valve (size in systole, degree of aortic regurgitation in diastole)—aortic regurgitation is usually associated with supracristal or perimembranous VSD • Estimation of right ventricular systolic pressure/degree of pulmonary hypertension Postoperative • Rule out residual ventricular septal defect • Estimation of right ventricular systolic pressure/degree of pulmonary hypertension • Assessment of associated defects • Ventricular function

with the visualization of the PDA, variations in position, alignment, and shape and length of the ductus. In order to see the entire ductus connect to the inferior curvature of the descending aorta, the probe should be rotated clockwise. Color Doppler can diagnose whether the flow is due to a PDA or not, by freezing or slowly moving frames in order

to trace the path of the jet of color Doppler flow. Although the jet appears to be arising from the bifurcation of the pulmonary artery, the actual origin of the shunt is in the descending thoracic aorta. The best view is the high left parasternal short-axis view above the level of the aortic valve, or a modified suprasternal view that achieves a long-axis view of the


right ventricular outflow tract and the main pulmonary artery. Color Doppler displays the bifurcation of the pulmonary artery and its branches, by angling the probe leftward and superiorly in the high parasternal short-axis view. The bifurcation of the main pulmonary artery may appear to “trifurcate” with the ductus arising along with left and right pulmonary arteries (Fig. 75.10).52 In a typical PDA with a left-to-right shunt, a color Doppler jet may be seen flowing through the left pulmonary artery into the main pulmonary artery with marked spectral dispersion in systole and diastole (throughout the cardiac cycle in adults). The maximal velocity is recorded by placing the Doppler sample volume just proximal to the bifurcation. The systolic and diastolic flow can be recorded from the high parasternal window, with an ultrasound beam aligned directly into the orifice of the PDA. Color Doppler will display diastolic flow from PDA along the lateral wall of the pulmonary artery, while pulsed wave Doppler will demonstrate flow reversal along the anterior wall of the pulmonary artery. The “machinery” murmur auscultation correlates with the continuous variation of the flow between systole and diastole on echocardiography. In the suprasternal view, pulsed wave Doppler may demonstrate holodiastolic flow reversal in the descending aorta due to antegrade flow into the ductus in diastole. Flow

Fig. 75.10: Diagrammatic representation of the high parasternal short-axis view on a transthoracic echocardiogram showing the bifurcation of the main pulmonary artery that may appear “trifurcate” with the ductus arising along with left and right pulmonary arteries. (Desc Ao: Descending aorta; LA: Left atrium; LPA: Left pulmonary artery; MPA: Main pulmonary artery; PDA: Patent ductus arteriosus; RA: Right atrium; RPA: Right pulmonary artery).

1807

across the ductus causes pressure equalization between the aorta and the pulmonary artery first in diastole but with increasing severity of pulmonary hypertension, the pressure difference between aorta and the pulmonary artery will decrease in systole. To improve the accuracy of estimated right ventricular systolic pressure calculated by using the modified Bernoulli’s equation (4V2), a bolus of saline is injected via peripheral intravenous catheter.53 This enhances the profile of the maximum tricuspid regurgitant jet velocity obtained on pulsed Doppler. The left heart chambers size depends upon the size of the PDA. Adults with a small PDA may have normal cardiac dimensions and no echocardiographic evidence of pulmonary hypertension, while those with moderate to large PDA may have left heart enlargement with impaired left ventricular function and varying degrees of pulmonary hypertension. A dilated, aneurysmal, and calcified main pulmonary artery may be seen in adults with a long-standing shunt past the third decade of life. In a dilated pulmonary artery, low velocity retrograde flow can be demonstrated in late systole. With rising pulmonary vascular resistance, there is a bidirectional shunt with right-to-left flow seen in early systole and a left-to-right flow seen in late systole/diastole. This may further deteriorate to irreversible pulmonary hypertension and Eisenmenger physiology. Although most PDAs occur in isolation, associated defects such as VSD, coarctation of aorta, and complex CHD should be evaluated. Coronary artery fistula, anomalous coronary artery, aortopulmonary collateral, ruptured sinus of Valsalva, and pulmonary regurgitation may appear like ductal flow, since they produce turbulence in the main pulmonary artery with color Doppler examination. Three-dimensional transthoracic echocardiography may be helpful in differentiating vascular structures from artifacts and echo dropouts. For a comprehensive assessment, one must acquire 3D color Doppler flow signals from the PDA jet, main pulmonary artery, and the descending thoracic aorta followed by rotation to view the flow signals from all sides at any desired angulation. By rotating these isolated color Doppler images from 0° to 180°, one can visualize flow in pulmonary arteries, PDA, and the descending aorta in three dimensions. Color Doppler 3D transthoracic echocardiography can also demonstrate flow signals moving from the pulmonary artery into the descending thoracic aorta in systole and back into the pulmonary artery in diastole.54–56

1808


Transesophageal Echocardiography In adults with limited acoustic windows, TEE is helpful in assessment of the PDA and associated defects. It may reveal more details such as the anatomy of ductus arteriosus and its relationship with the descending aorta and pulmonary artery. Real time 3D TEE helps in imaging of the PDA, before and after Amplatzer device closure. However, the cranial part of the aortic arch cannot be visualized because of the near-field artifact.54 Live 3D TEE plays a major role in the perioperative monitoring during transcatheter device closure by cutting down the fluoroscopy time. It is useful in defining the

anatomical details, confirming the position of the device after closure, and ruling out a residual shunt.56 A synopsis of echocardiographic assessment of the PDA is reviewed in Table 75.8.

Cardiac Catheterization Cardiac catheterization is primarily performed at the time of device closure to determine the anatomy of the ductus, degree of shunt, pulmonary vascular resistance (PVR), pulmonary vasoreactivity, associated defects, and coronary artery disease in older adults. Catheter-based device closure is mainly guided by fluoroscopy and partially by TEE.

Table 75.8: Patent Ductus Arteriosus

Associated defects • Usually occurs as an isolated anomaly May be associated with the following defects: • Ventricular septal defect • Coarctation of aorta • Valvular defects—aortic or mitral valves • Complex CHDs—in association with complex defects such as congenitally corrected transposition of the great arteries or tetralogy of Fallot. Echocardiographic assessment • Identification of the defect—when visible, the bifurcation of the main pulmonary artery may appear “trifurcate” with the ductus arising along with left and right pulmonary arteries—measure length and width when possible • Color Doppler—jet seen through the left pulmonary artery into the main pulmonary artery with marked spectral dispersion in systole and diastole (throughout the cardiac cycle in adults) in a typical PDA with a left-to-right shunt • Assessment of pressure gradient across the PDA • Measurement of left ventricular dimensions and quantitative assessment of left ventricular function—left heart enlargement is common with moderate to large PDA • Estimation of right ventricular systolic pressures/pulmonary hypertension (right ventricular hypertrophy occurs in adults with Eisenmenger physiology) • Rule out pulmonary artery dilatation, aneurysm, or calcification (often noted by the fourth decade of life) • Assessment of the aortic arch—rule out flow acceleration/obstruction, diastolic flow reversal Postoperative • Left ventricular size and function, left atrial enlargement • Rule out residual shunts • Ensure proper device placement (a well-seated device can be visualized between the pulmonary artery bifurcation and the inferior margin of the aorta. It should not protrude into the aortic lumen or the pulmonary artery)


Magnetic Resonance Imaging/Computed Tomography These modalities are rarely required for imaging an isolated PDA for determining suitability for device closure.

1809

AV valve between the atria and ventricles. The cleft in the left-sided AV valve leaflet results from incomplete fusion of the superior and inferior bridging leaflets of the AV valve.

Echocardiography PDA Closure The ACC/AHA Class I recommendations3 for device or surgical closure of PDA in adults are: • Left heart enlargement (atrial and/or ventricular) due to volume overload or in the presence of pulmonary hypertension due to a left-to-right shunt • History of endarteritis. Surgical or device closure of PDA is contraindicated in adults with severe pulmonary hypertension due to reversal of the shunt (right to left). Calcification and tissue friability in adults can make surgical closure challenging and therefore, it is performed in limited cases. Surgery instead of device closure should be considered in adults who have calcified PDA, ductal aneurysm, history of endarteritis, and very large PDAs.

The AV septal defects are best seen in the apical-four chamber views. The complete AV is classified into three Rastelli types based on the extent of chordal attachments of the superior bridging leaflet. This defect may be associated with Down syndrome.31 Two-dimensional echocardiography defines the size of the AV septal defect, AV valve attachments, and determines the presence of a common AV valve or two separate AV valves. A distinctive feature of AV septal defect is the bridging leaflets of the AV valves that are viewed in the same horizontal plane, on an apical four-chamber view (Fig. 75.11). A cleft anterior mitral valve is identified in the parasternal short-axis view (Fig. 75.12). Color Doppler is used to estimate the severity of the AV valve regurgitation, and the level, size, direction of atrial and ventricular shunts.

The Postoperative Adult Transthoracic echocardiogram and color Doppler are used in long-term follow-up after device closure or surgery. Postoperatively, proper device placement is confirmed by visualizing a well-seated device between the pulmonary artery bifurcation and the inferior margin of the aorta, without any protrusion into the pulmonary artery or aortic lumen. In the immediate postoperative period, residual shunts should also be ruled out. On subsequent echocardiograms, smaller shunts are likely to resolve due to endothelialization over time.

Atrioventricular Septal Defect Atrioventricular septum is the partition between the left ventricular outflow tract and facing right atrium in normal hearts.31 Morphological variations in the anomalies of the AV septum and the AV valves present as various types of AV septal defects.57 In partial AV septal defects, there is primum ASD, with two separate AV valves, a cleft mitral valve, and no VSD; in intermediate AV septal defect, in addition to these findings, there is a small restrictive membranous VSD; while in complete AV septal defect, there is a large septal defect extending from the primum atrial to the perimembranous ventricular septum with a common

Fig. 75.11: Diagrammatic representation of the transthoracic apical four-chamber view showing the distinctive feature of AV septal defect with the bridging leaflets of the AV valves viewed in the same horizontal plane (as shown with the dotted line). (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; PV: Pulmonary vein; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve).

1810


Fig. 75.12: Transthoracic echocardiogram showing a cleft anterior mitral valve (MV) in the parasternal short-axis view. (AMVL: Anterior mitral valve leaflet; PMVL: Posterior mitral valve leaflet).

Live/real time 3D TTE shows incremental value over 2D TTE in the evaluation of an adult with a complete AV septal defect. Most importantly, it provides an en face view of all the five leaflets of the common AV valve. It allows more detailed evaluation of shunts (especially from the left ventricle to right atrium), quantitative assessment of regurgitant lesions, and classification into one of the three Rastelli types.58,59

The Postoperative Adult Postoperative long-term issues that are assessed by echocardiography include a search for a residual shunt lesion (post-AV patch repair), degree of mitral (left AV valve) or tricuspid regurgitation, right ventricular systolic pressure, degree of mitral stenosis following surgery of cleft mitral valve, or subaortic stenosis due to the long left ventricular outflow tract that manifests as a “gooseneck deformity” on cardiac catheterization. A synopsis of the echocardiographic assessment of AV septal defects is reviewed in Table 75.9.

Persistent Left Superior Vena Cava Left superior vena cava (LSVC) is the most common thoracic venous abnormality.60 It is the embryological remnant of the persistent left anterior cardinal vein. Its prevalence varies from around 0.3% in the general population to 10% in patients with CHD. The LSVC usually drains via the

coronary sinus into the right atrium in the rarest type of ASD called the “unroofed coronary sinus defect.” It may be associated with other defects such as a bicuspid aortic valve, coarctation of the aorta, or cor triatriatum. In 20% of those who have a persistent LVNC, the right superior vena cava may be absent, leading to marked dilatation of the coronary sinus because of increased blood flow.31 The right superior vena cava may be absent in approximately 15% to 30% of the individuals born with a persistent LSVC. These individuals have a high likelihood of having an enlarged coronary sinus because of markedly increased blood flow into the LSVC.60 The LSVC is often an incidental finding in asymptomatic adults. It may be of clinical significance during pacemaker/ defibrillator implantation, central venous catheter placement, and in patients undergoing cardiopulmonary bypass surgery during retrograde cardioplegia, since the solution can perfuse retrograde into the left persistent superior vena cava, thereby decreasing the effectiveness of cardioplegia.

Echocardiography TTE with an agitated saline contrast study helps in making the diagnosis. The agitated saline contrast injection (“bubble” study) in the left arm via a peripheral intravenous catheter flows into the left brachiocephalic vein with appearance of microbubbles in the left atrium in case of an unroofed coronary sinus. If the LSVC is draining into an intact enlarged coronary sinus, an injection into either the right or left arms (through a peripheral intravenous catheter) will demonstrate the microbubbles in the enlarged coronary sinus and then in the dilated right heart.61 If the right superior vena cava is absent, the injection of agitated saline contrast into the right arm will first appear in the enlarged coronary sinus followed by the right atrium.62

Magnetic Resonance Imaging/Computed Tomography Often the LSVC and all the pulmonary veins cannot be easily identified by TTE or TEE. Like other extracardiac structures, the LSCV can clearly be identified on MRI or CTA with 3D reconstruction.60,61


1811

Table 75.9: AV Septal Defect

Associated defects—Usually occurs in patients with Down syndrome • Patent ductus arteriosus—most common • AV valve regurgitation • Coarctation of the aorta • Left ventricular outflow tract obstruction • Double orifice mitral valve • Muscular ventricular septal defects • Right ventricular outflow tract obstruction • Pulmonary stenosis • Left ventricle-to-right atrial shunt • Gerbode defect—right ventricle-to-left atrial shunt Echocardiographic assessment • Identification of the defect – Primum atrial septal defect – Inlet ventricular septal defect – Cleft anterior mitral valve – Tricuspid commissure—widened (anteroseptal) • Estimation of right ventricular systolic pressures/pulmonary hypertension (right ventricular hypertrophy occurs in adults with Eisenmenger physiology) • Left ventricular size and function • Right ventricular size and function • Assessment of the size and the gradient across the atrial and ventricular shunt • Degree of AV valve regurgitation • Severity of the associated defects Postoperative • Biventricular size and function • Rule out residual shunts • Degree of AV valve regurgitation—especially mitral regurgitation due to cleft mitral valve

The Postoperative Adult Adults with LSVC associated with coronary sinus defect and partial anomalous pulmonary venous return require patch closure of the coronary sinus type of ASD and an intracardiac baffle to redirect the anomalous pulmonary venous flow into the left atrium. Follow-up echocardiography focuses on ruling out residual shunts and persistent pulmonary hypertension from previously long-standing left-to-right shunts.

Sinus of Valsalva Aneurysm Sinus of Valsalva aneurysm may be congenital or acquired with clinical presentation ranging from an asymptomatic

murmur to acute cardiogenic shock. Aneurysm formation in the aortic sinus can occur at the junction of the aorta and the annular fibrosa, due to structural wall abnormalities. It may extend to surrounding structures, causing obstruction or fistulae. An unruptured aneurysm may go undiagnosed until it causes symptoms due to right ventricular outflow obstruction.63 A small perforation may come to our attention on physical examination because of a continuous murmur on auscultation. An acute rupture may result in high output decompensated heart failure. Coronary artery compression may present as chest pain due to ischemia. Since the sinus of Valsalva aneurysms originate more commonly from the right coronary or the noncoronary cusp, they are more likely to cause right coronary artery compression.

1812


The differential diagnoses include an acquired aneurysm from complicated infective endocarditis, a coronary artery fistula, an aneurysm of the membranous ventricular septum, or a PDA. A normal coronary origin with normal coronary lumen favors the diagnosis of sinus of Valsalva aneurysm. Its location in aortic sinus above the plane of the origin of the coronaries distinguishes it from aneurysm of the membranous ventricular septum. In adults with acquired aneurysm following complicated infective endocarditis, the fistula does not have an extended finger-like aneurysmal extension from the base to the apex as seen in the sinus of Valsalva aneurysm.

Echocardiography

chamber or vascular structure. The morphology can be complex with single or multiple communications that may form a maze of fine intramural channels communicating with each other. It most commonly affects the right side of the heart.65 The clinical presentation depends upon the size of the shunt and the structures involved. Most coronary fistulae drain into the right heart structures. Adults with a large shunt may present with heart failure or angina due to coronary steal phenomenon caused by diversion of blood flow away from the territory supplied by the coronary, into the site of drainage (right heart, pulmonary artery, or superior vena cava).

Two-dimensional echocardiography shows an aneurysmal sac, which can present as an abnormal, circular, thinwalled structure protruding into a heart chamber. Ruptured aneurysms will lead to chamber enlargement over time. Color Doppler with transthoracic echocardiogram will show flow originating in the aorta and flowing into a heart chamber (usually the right ventricle) in a ruptured aneurysm. Multiple views, starting with the parasternal long-axis and short-axis views at the level of the aortic root, are required to locate the sinus from which the aneurysm originated. The transducer is then angulated to obtain modified views and locate the aneurysm (usually above the aortic cusps). Contrast echocardiography allows more precise definition of the aneurysmal sac. It aids in the diagnosis of a left-to-right shunt by demonstrating a negative contrast image in the right chambers with a ruptured aneurysm and no negative contrast image with an unruptured aneurysm.64 TEE delineates the anatomical details such as the site of origin by displaying the aortic root and sinuses more clearly. Three-dimensional echocardiography adds incremental value by further defining the spatial relationships between the aneurysm and the cavity into which it drains. Associated echocardiographic findings include aortic regurgitation resulting from altered aortic root anatomy. However, if there is severe aortic regurgitation, one must rule out extensive damage to the aortic leaflets by endocarditis or acute rupture of sinus of Valsalva aneurysm. Chronic small fistulae with a left-to-right shunt cause left heart enlargement or right atrial enlargement when the fistula drains into the right atrium.

Echocardiography

Coronary Artery Fistula

Fig. 75.13: Transthoracic echocardiogram (high parasternal short-axis view) showing the site of drainage of a coronary artery fistula. (LA: Left atrium; PA: Pulmonary artery; RVOT: Right ventricular outflow tract).

Coronary artery fistula is defined as an abnormal communication between a coronary artery and a cardiac

On a transthoracic echocardiogram, a markedly enlarged proximal part of the involved coronary artery alerts the echocardiographer of its presence. The structure or the cardiac chamber to which the coronary artery fistula drains is also enlarged in those with significant longstanding shunts. The parasternal long-axis views with color Doppler focusing on the aortic root may also bring it to our attention. A high parasternal short-axis view and its modifications help in identifying its origin and site of drainage (Fig. 75.13). However, 2D transthoracic echocardiography is limited in its ability to reliably trace the course of the fistula as well as the site of drainage in many adults.66


TEE offers better spatial resolution and delineates the course of coronary artery fistula from its origin to the chambers into which it is draining in multiplane views.67 Three-dimensional TEE with its ability to provide en face views has been reported to reveal morphology and dimensions of the coronary artery fistulae more comprehensively.68,69

Cardiac Catheterization Cardiac catheterization is best tool for diagnosing and tracing the entire course of the coronary artery. Coronary angiography also allows accurate assessment of obstructive coronary atherosclerosis is adults who are at higher cardiovascular risk. While small coronary fistulae do not require closure, the larger ones may require percutaneous closure or surgery to avoid the risk for developing heart failure or angina.

Magnetic Resonance Imaging/Computed Tomography MRI/CTA are the best noninvasive imaging modalities for defining the course of the coronary arteries and the enlargement of the chambers. The number of incidentally detected coronary artery fistulae in the era of multidetector CT scanning has increased.65

Surgery for Sinus of Valsalva Aneurysms and Coronary Artery Fistulae Surgical repair, ligation, bypass, or percutaneous closure should be considered before the development of potential complications such as cardiac failure, infectious endocarditis, embolization, pulmonary hypertension, arrhythmia, or ischemia related to myocardial hypoperfusion, aortic regurgitation, dissection, rupture, or death.70

The Postoperative Adult Postoperatively, adults need follow-up echocardiography to rule out residual patch leaks, compression of surrounding structures, and resolution of chamber enlargement and assessment of ventricular function.

1813

VALVULAR DISEASE Tricuspid Valve Ebstein’s Anomaly First described by Wilhelm Ebstein in 1866, this rare cyanotic CHD occurs in <1% of CHD with varying degree of apparent apical displacement of the point of attachment of the basal insertions of the septal and posterior leaflets of the tricuspid valve.71 Due to failure of delamination, there is adherence of tricuspid valve leaflets to the underlying myocardium. In addition, there is apical displacement of the functional tricuspid valve annulus with the septal leaflets more apically displaced than the posterior, followed by the anterior leaflets.72 The malformed tricuspid valve may be incompetent, stenotic, or rarely, imperforate. If the right ventricle is subdivided into the inlet, trabecular, and outlet portions, then the displacement of the tricuspid orifice to the junction of the inlet and trabecular ventricular zones describes the essence of this anomaly.73 Due to “atrialization” of the right ventricle, by the downward displacement of the functional tricuspid annulus, the right atrium appears larger than its actual size. The right ventricle, therefore, appears to be smaller and may have impaired function over time. The left ventricular function may also decrease in adulthood. The downward displacement of the septal tricuspid valve leaflet is associated with discontinuity of the central fibrous body and septal atrioventricular ring, thus creating a potential substrate for accessory atrioventricular connections and ventricular pre-excitation, making the patient at risk for sudden death. Right heart catheterization, therefore, carries a risk of inducing ventricular arrhythmias leading to sudden cardiac death. On angiography, morphofunctional abnormalities of the left ventricle have been demonstrated in many patients, which may be explained by increased fibrosis in the left ventricular wall and the ventricular septum as demonstrated by histological studies.74 The anterior tricuspid leaflet may be fenestrated and redundant, giving it a “sail-like” appearance. The septal leaflet may be tethered. The severity of tricuspid regurgitation, presence of a PFO, or ASD determines clinical outcomes. This defect is often associated with pulmonary stenosis/atresia and VSDs, congenitally corrected transposition of the great arteries, and tetralogy of Fallot.31

1814


The term “Ebstenoid” or “Ebstein-like” may be used to describe the broad spectrum of variations in morphology of the “typical” Ebstein’s valve. Although it is usually diagnosed in childhood, milder variations may be noted on echocardiography in adulthood when the individual presents with dyspnea, decreasing exercise tolerance, right heart failure, and worsening atrial arrhythmias. The common arrhythmias are atrial fibrillation/flutter or supraventricular tachycardia due to Wolff–Parkinson– White (WPW) syndrome in 15% to 20% adults. Cyanosis occurs in the presence of an atrial shunt (PFO or ASD) that may also increase the risk of paradoxical embolism leading to transient ischemic attack or stroke.

Echocardiography In the current era, Ebstein’s anomaly is most commonly diagnosed by echocardiography.72 On transthoracic echocardiography, the Ebstein’s tricuspid valve is best seen in the apical four-chamber view with its characteristic “sail-like” elongated anterior leaflet and the “downward displacement” of the septal leaflet caused by the tethering to the septum, making it appear as though it is attached apically in relation to the point of attachment of the anterior mitral leaflet (Fig. 75.14). The diagnostic feature of Ebstein’s anomaly is an apical displacement of both the septal and the posterior tricuspid leaflets, exceeding 20 mm or 8 mm/m2 in adults.75 In an apical four-chamber view, this distance is measured from the point of attachment of the

Fig. 75.14: Transthoracic echocardiogram showing Ebstein’s valve in an apical four-chamber view with its characteristic “saillike” elongated anterior leaflet and the “downward displacement” of the septal leaflet. (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve).

anterior mitral valve leaflet to the point of attachment of the septal tricuspid valve leaflet. This view also shows severity of tricuspid regurgitation, its impact on the right atrial enlargement, and biventricular ventricular function (Fig. 75.15). The parasternal short-axis view may also help define the tricuspid valve anatomy. Tricuspid valve features associated with decreased functional capacity are absence of the septal leaflet, pronounced tethering, restricted leaflet motion, and displacement of the anterior leaflet.76 Associated defects such as pulmonary stenosis and shunts (PFO/ASD/VSD) are also to be followed-up on serial echocardiograms. TEE with agitated saline contrast is used to indentify a patent foramen ovale in adults with poor acoustic windows. A synopsis of echocardiographic assessment is reviewed in Table 75.10.

Stress Echocardiography Stress echocardiography with treadmill testing offers an objective assessment of functional capacity, ventricular contractile reserve, impact of exercise on arrhythmias, and cyanosis in adults with Ebstein’s anomaly.

Magnetic Resonance Imaging/Computed Tomography MRI/CTA allows quantification of biventricular function and assessment of tricuspid valve morphology in adults

Fig. 75.15: Transthoracic echocardiogram showing Ebstein’s valve in the apical four-chamber view associated with tricuspid regurgitation. (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve).


1815

Table 75.10: Ebstein’s Anomaly

Associated defects •

Patent foramen ovale

•

Atrial septal defect

•

Ventricle septal defect

•

Patent ductus arteriosus (PDA)

•

Pulmonary stenosis or atresia

•

Congenitally corrected transposition of the great arteries (CCTGA)

•

Left ventricular noncompaction (LVNC)—40%

•

Tetralogy of Fallot

Echocardiographic assessment •

Identify the large “sail-like” anterior tricuspid leaflet

•

Degree of tricuspid valve displacement (septal leaflet attachment)

•

Right ventricular size and function

•

Degree of tricuspid regurgitation

•

Right atrial enlargement—usually marked

•

Left ventricular size and function

Postoperative •

Biventricular size and function

•

Degree of tricuspid regurgitation

•

Right atrial enlargement

•

Rule out residual shunts

with limited acoustic windows, who are unable to have a TEE. MRI allows better visualization of the posterior tricuspid valve leaflet, tricuspid valve fenestrations, quantification of right heart size, and right ventricular ejection fraction, while echocardiography is more accurate in assessment of valve morphology and detecting small shunt lesions. Echocardiography and MRI provide complementary data for appropriate risk stratification prior to surgery.72

Cardiac Catheterization Coronary angiography is performed before surgical intervention in patients at risk for coronary artery disease or for assessment of pulmonary vasoreactivity in adults with severe pulmonary hypertension.

Tricuspid valve repair or replacement with PFO/ASD closure is performed in: • A symptomatic adult with right heart failure, declining exercise capacity, or progressive right ventricular dilation/impaired right ventricular systolic function with worsening atrial and/or ventricular arrhythmias • Worsening cyanosis with oxygen saturation < 90% • Transient ischemic attack or stroke attributed to paradoxical embolism • Increased cardiac silhouette on imaging. At the time of surgery for the tricuspid valve and associated defects, the Maze procedure is performed for atrial arrhythmias, since catheter-based ablation is far more challenging in adults with Ebstein’s anomaly due to multiple accessory pathways. For those with previous tricuspid valve surgery, reoperation is indicated for impaired valvular function.

Tricuspid Valve Surgery The ACC/AHA Class I recommendations for surgical treatment for adults with Ebstein’s anomaly are the following:3

The Postoperative Adult The postoperative adult with Ebstein’s anomaly needs follow-up for tricuspid regurgitation postrepair, assessment

1816


of prosthetic valve function, biventricular function, and residual shunts.

Pulmonary Valve Pulmonary Stenosis While the majority of the individuals have narrowing of the pulmonary valve at the valvular level, stenosis may occur at the subvalvular or supravalvular levels. Among the three morphological types, the commonest one is the domeshaped pulmonary valve—a mobile valve with narrow central opening and systolic doming seen on echocardiography. It is usually associated with main pulmonary artery dilatation that results from structural abnormalities.11 The three rudimentary raphe fuse to cause valve stenosis that may increase in severity due to calcification. Over time, pulmonary regurgitation may develop and the jet usually directed toward the left pulmonary artery. Other associated defects are ASD, VSD, and infundibular or right ventricular hypertrophy leading to dynamic obstruction of the right ventricular outflow tract.31 Dysplastic pulmonary valve has significant myxomatous thickening of the valve leaflets that reduces leaflet mobility. Associated commonly with Noonan syndrome, it may also manifest with narrowing of the pulmonary annulus and the right ventricular outflow tract. Unicuspid or bicuspid pulmonary valve may rarely be seen in adults with tetralogy of Fallot. The quadricuspid pulmonary valve has been reported as a rare finding in literature, with a rudimentary accessory cusp interposed between three cusps of same size in most cases. It may present with stenosis/regurgitation and pulmonary artery dilatation/aneurysm. The most common CHDs associated with it are ASD, VSD, PDA, and bicuspid aortic valve.78

Echocardiography The era of echocardiographic detection of the pulmonary valve was heralded by Dr Nanda who published his findings in 1972.77 On 2D transthoracic echocardiography, the parasternal short-axis view at the level of the aorta is the best view for assessment of the pulmonary valve morphology and assessment of regurgitation or stenosis. The parasternal long-axis view displays the right ventricular outflow tract. The level and severity of the stenoses are important in determining the timing for intervention or surgery. Standard grading ranges from mild (peak valvular gradient

< 30 mm Hg), moderate (peak valvular gradient between 30 and 50 mm Hg), and severe (peak valvular gradient > 50 mm Hg). Silvilairat et al. raised a possibility that the mean Doppler gradient may be the preferred method for accurately estimating the severity of the pulmonary valve stenosis, since it correlates best with the peak-to-peak gradient obtained by cardiac catheterization. According to their study, estimation of only the peak (maximum) valvular gradient may lead to overestimation of the severity of pulmonary stenosis.78 Further studies are required to figure out why exactly Doppler mean pressure gradients and catheterization peak-to-peak pressure gradients seem to show good correlation.79 Long-standing unoperated severe pulmonary stenosis leads to right ventricular hypertrophy, and systolic flattening of the interventricular septum due to increased pressure overload on the right heart. Spectral Doppler examination may reveal a “dagger-shaped,” late-peaking systolic signal characteristic of significant dynamic obstruction of the right ventricular outflow tract. The right ventricular size, mass, and systolic function along with pulmonary regurgitation and pulmonary artery dimensions should be assessed on echocardiography. The pulmonary artery may be considered as dilated when: (a) a ratio of maximum pulmonary artery diameter (usually measured at the point of bifurcation into right and left branches) to the aortic diameter (measured at the level of the aortic valve or 2 cm beyond the aortic valve) is ≥1.4; and (b) a ratio of pulmonary ring to the aortic ring diameters is ≥1.5.80 Nearly half the pulmonary artery aneurysms are associated with CHD. Besides pulmonary valve stenosis, they may occur in individuals with pulmonary regurgitation, ASD, PDA, VSD, tetralogy of Fallot, and Eisenmenger syndrome. The presence of a thrombus should be ruled out.81 TEE is very important for examining the cusp anatomy of the pulmonary valve in the short-axis view. The best view to visualize this valve is a modified view, with the TEE probe anteroflexed between 135° and 145°, so that it aligns the pulmonary valve into the short axis and the aortic valve into long axis.78 In individuals with limited transthoracic windows, TEE also helps in delineating the right ventricular outflow tract and lesions in the branch pulmonary arteries. A synopsis of echocardiographic assessment is reviewed in Table 75.11.


1817

Table 75.11: Pulmonary Stenosis



•


•

Ventricular septal defect

•

Peripheral pulmonary stenosis

•

Patent ductus arteriosus


Type of valve—dome-shaped, dysplastic or quadricuspid

•

Valve annulus

•

Thickness of the leaflets

•

Gradient—degree of stenosis

•

Concomitant pulmonary regurgitation

•

Pulmonary artery dimensions—dilatation, aneurysm or narrowing

•

Subvalvular area—infundibular obstruction/hypertrophy

•


Postoperative •

Valve gradient—stenosis

•

Concomitant pulmonary regurgitation

•

Pulmonary artery dimensions—dilatation, aneurysm or narrowing

Cardiac Catheterization Cardiac catheterization is rarely necessary for diagnosis and is usually performed when catheter-based intervention is indicated. For confirmation, the gradients should be obtained at the valvular, sub-, and supravalvular levels. The presence of obstruction in the infundibulum as well as main, branch, or peripheral pulmonary arteries should be ruled out. It is important to note again that the peakto-peak gradient by cardiac catheterization correlates best with the mean Doppler rather than with the peak instantaneous Doppler gradient.78 Right ventriculogram is performed for assessment of the right ventricular function and degree of pulmonary regurgitation.

Magnetic Resonance Imaging/Computed Tomography MRI/CTA are indicated for accurate imaging of the main, branch, and peripheral pulmonary arteries, quantification of right ventricular systolic function and degree of pulmonary regurgitation.

Pulmonary Valve Intervention (Valvotomy) and Surgery (Replacement) The Class I ACC/AHA recommendations for interventional and surgical treatment for adults with valvular pulmonary stenosis are the following:3 Catheter-based intervention with balloon valvotomy in: • Asymptomatic adults with a domed pulmonary valve with a mean Doppler gradient > 40 mm Hg (peak instantaneous Doppler gradient > 60 mm Hg) if the degree of pulmonic regurgitation is less than moderate • Symptomatic adults with a domed pulmonary valve with a mean Doppler gradient > 30 mm Hg (a peak instantaneous Doppler gradient > 50 mm Hg) if the degree of pulmonic valve regurgitation is less than moderate. Surgery is performed for the following indications: • Adults with severe pulmonary stenosis and associated defects such ASD, severe pulmonary regurgitation, or stenosis at other levels (subvalvular/supravalvular pulmonary stenosis or hypoplastic pulmonary annulus)

1818


• •

Dysplastic thickened pulmonary valve Concomitant surgery is indicated for associated lesions such as severe tricuspid regurgitation, a surgical Maze for atrial fibrillation, or when the main pulmonary artery is markedly dilated (usually over 4 cm) and is causing symptoms by compressing on contiguous structures. Of note, there are no clear cut guidelines for surgery in an adult who has a dilated main pulmonary artery that is associated with a dome-shaped pulmonary valve. There is less likelihood of rupture of these lowpressure aneurysms. Hence, pulmonary arterioplasty or main pulmonary artery replacement with a tube graft/ valved tube graft is performed when there are significant symptoms due to compression on contiguous structures or when concomitant surgery is otherwise indicated. Bioprosthetic pulmonary valves are chosen because, despite anticoagulation, the low pulmonary artery pressure and slow blood flow puts these individuals at a high risk of valve thrombosis with mechanical prosthetic valves.

The Postoperative Adult Besides the assessment of native/prosthetic valve function, the main pulmonary artery should be evaluated for dilatation. On long-term follow-up after surgery, increasing severity of pulmonary regurgitation has been reported. Following percutaneous balloon angioplasty, reinterventions may be required for recurrence of pulmonary stenosis, and mild pulmonary regurgitation is common.82

Mitral Valve Cor Triatriatum Also known as cor triatriatum sinister, this is a very rare cardiac defect that may go undiagnosed into adulthood especially when it presents as an isolated anomaly. It is characterized by a perforated membrane (partial or complete) dividing the left atrium into two chambers— the proximal (pulmonary venous chamber) receives the pulmonary veins, and the distal “true” chamber comprises the left atrium with the fossa ovalis and left atrial appendage.31 Associated defects include patent foramen ovale, secundum ASD, and rarely a common atrium. Adults usually present with symptoms similar to mitral stenosis due to obstruction to flow through the perforated

membrane because of fibrosis or calcification. Others may develop atrial fibrillation or mitral regurgitation. The differential diagnosis includes a supravalvular mitral ring or left atrial dissection. Hemodynamically, it may mimic pulmonary vein stenosis or left atrial mass (tumor, thrombus, or cyst).83–85

Echocardiography The best view is the apical four-chamber view that shows a thin undulating membrane moving toward the mitral valve in diastole and away from it in systole. The proximal chamber is usually dilated due to a “back up” of flow caused by obstruction through the perforated membrane into the “low pressure” distal chamber. The left atrial appendage is usually normal in size. Color flow Doppler shows flow acceleration at the sites of perforations in the membrane. The right ventricular systolic pressure should be estimated from the tricuspid regurgitant jet to rule out pulmonary hypertension. It is important to establish the position of the left atrial appendage in the distal chamber in order to confirm cor triatriatum and exclude a supravalvular mitral ring.86 Transesophageal echocardiography is useful in confirming the diagnosis by clearly delineating the position of the left atrial appendage. It also allows complete assessment of any associated intracardiac defects such as the patent foramen ovale.83 Contrast echocardiography is an important adjuvant technique where the perforation in the membrane cannot be delineated by color Doppler. It shows a differential opacification of the proximal versus the distal chamber with delayed emptying of contrast into the distal chamber through the communication between the chambers.85 Three-dimensional reconstruction is useful in diagnosing cor triatriatum by defining atrial membranes and the associated defects.87 Although these echocardiographic modalities may suffice, in some cases a left and right heart catheterization with simultaneous pulmonary capillary wedge and left ventricular end-diastolic pressure measurements may be required to reveal a significant mean gradient, prior to definitive surgical resection of the membrane.

Cleft Mitral Valve A cleft mitral valve can occur as an isolated defect or in association with other CHD. The cleft can be in the anterior leaflet usually in association with a primum ASD or may occur in the posterior leaflet.88,89 Other defects


associated with a cleft mitral valve are atrioventricular septal defect, secundum ASD, VSD, coarctation of aorta, double outlet right ventricle, and tricuspid atresia. The long-term sequelae are left atrial enlargement and left ventricular enlargement with impaired function due to progressive mitral regurgitation. These adults are also at risk for developing endocarditis, atrial arrhythmias, and pulmonary hypertension. It is best seen in the parasternal short-axis view (Fig. 75.12). The direction of mitral regurgitation jet and its severity can be assessed based on the data compiled from the parasternal long-axis, apical two-chamber, fourchamber, and subcostal views. The 3D echocardiography en face view shows the location of the cleft in relation to the scallops of the mitral leaflet most clearly.90 The indications for surgery are similar to those for acquired mitral regurgitation. Surgical treatment involves reconstruction with ring annuloplasty or mitral valve replacement.

1819

coarctation of aorta, VSD, and subaortic stenosis. It may occur in association with more complex defects such as Shone’s syndrome, transposition of the great arteries, truncus arteriosus, tricuspid atresia, Ebstein’s anomaly, and double outlet right ventricle.91 The clinical presentation of DOMV is variable and may go undiagnosed until adulthood unless there are significant mitral regurgitation, mitral stenosis, or associated cardiac defects. Mitral regurgitation appears to occur more frequently than mitral stenosis.

Echocardiography

In this rare congenital malformation, abnormal fusion of the endocardial cushion leads to two equal or unequal mitral valve orifices. Double orifice mitral valve (DOMV) with intact atrioventricular septum can present as reduplication of the orifice caused by two separate valve orifices supported by their own separate subvalvular apparatus. On the other hand, it can occur in association with an atrioventricular (AV) septal defect with a fibrous bridge across the mitral orifice. There may be abnormal papillary muscle rotation, fusion, or a single papillary muscle. Besides partial or complete AVSD, other associated defects include atrial septal defect,

It is usually best seen in the parasternal short-axis view. Other views are the subcostal short-axis view at the level of the mitral valve and the apical four-chamber view. Das et al. described the transthoracic echocardiographic views that help in determining various morphology of the DOMV; for the DOMV with complete bridging, the best views are the parasternal or subcostal short-axis with a sweeping of the transducer from base to apex; for DOMV with incomplete bridging, a single opening of the mitral valve appears on basal cuts in the short-axis views and then the double orifice becomes apparent only when the transducer is carefully swept toward the apex; for the hole-type DOMV, an apical four-chamber is the preferred view. In their study, they reported that a smaller, accessory orifice was located in the anterior leaflet of the mitral valve in all cases.92 The mitral valve may rarely be normal functioning and more often be stenotic or regurgitant. The mitral valve area is calculated as the sum of the area of the two mitral orifices (Figs 75.16A and B). Isolated DOMV with normally

A

B

Double Orifice Mitral Valve

Figs 75.16A and B: Transthoracic echocardiogram showing that the mitral valve area in an adult with a double orifice mitral valve (DOMV) is calculated as the sum of the area of the two separate mitral orifices (A and B), in the parasternal short-axis views by planimetry.

1820


functioning valves may go unrecognized until later in life and then only discovered as an incidental finding.93 DOMVs presenting in association with other defects, such as atrioventricular (AV) septal defect, VSD, ASD, Ebstein’s anomaly, tetralogy of Fallot, left heart obstructive lesions, and coarctation of aorta, are more likely to be diagnosed in childhood and undergo surgical repair or replacement of the mitral valve.

Parachute Mitral Valve The parachute mitral valve is a variant of abnormal attachment of the mitral valve chordae to a solitary or fused papillary muscle. This can result in mitral stenosis due to a restrictive valve opening, as subvalvular obstruction due to fused chordae, or it can rarely present with mitral regurgitation because of prolapsed mitral valve. It can also present as an isolated anomaly or part of the Shone’s complex, which is characterized by a supravalvular membrane or ring, parachute mitral valve, subaortic stenosis, and coarctation of aorta.94 It may occur with other lesions such as an ASD or bicuspid aortic valve with stenosis. Most cases present in infancy and are operated early.95,96 In rare cases, parachute mitral valve with Shone’s complex may go undiagnosed into adulthood.97 The majority present with dyspnea, decreasing exercise tolerance, or atrial fibrillation due to stenosis or regurgitation, while in others the finding is incidental.

Transesophageal Echocardiography TEE offers a more detailed analysis of the defect and isolated defects in multiplane views. It often allows differentiation between a true parachute and parachutelike mitral valve. In a parachute-like mitral valve, most of the chordae tendinae are attached to a main papillary muscle while the other papillary muscle is hypoplastic and close to the main one.98 TEE should also be considered when the severity of stenosis or regurgitation indicates surgery in accordance with the ACC/AHA guidelines for valvular disease.99 The ACC/AHA Class I recommendations for surgical treatment for young adults with mitral valve disease are the following:99 Congenital Mitral Stenosis: • Symptomatic young adult patients with congenital mitral stenosis and NYHA functional Class III or IV, who have a mean mitral valve gradient > 10 mm Hg on Doppler echocardiography. Other Class I indications that apply to all mitral valve disorders include: • Symptomatic adults with NYHA functional Class III–IV, who have moderate or severe mitral stenosis measured by other methods when percutaneous mitral balloon valvotomy is either not available; contraindicated because of concomitant moderate to severe mitral regurgitation; persistent left atrial thrombus despite anticoagulation; or unfavorable mitral valve morphology.

Echocardiography The transthoracic parasternal long-axis and shortaxis views (at the level of the papillary muscle), apical four-chamber and two-chamber views are valuable in assessment of the morphology of the mitral valve, subvalvular apparatus, papillary muscle, and associated left heart lesions. The parasternal long-axis view may show chordae tendinae converging to the single papillary muscle either as short, thickened, underdeveloped, and adherent causing stenosis, versus elongated and floppy without adequate coaptation of the mitral valve leaflets/prolapse resulting in mitral regurgitation. In the parasternal shortaxis view at the midpapillary level, a single papillary is visualized posteromedially and the mitral orifice may be eccentric. In the parasternal short-axis view at the basal level, parachute leaflets described as typical for this condition are often seen.

Mitral Regurgitation Mitral valve repair is preferred over MV replacement in most cases: • Symptomatic adult with severe congenital mitral regurgitation with NYHA functional Class III or IV symptoms • Asymptomatic adult with severe congenital mitral regurgitation and left ventricular ejection fraction ≤ 60% • Severe mitral regurgitation with NYHA functional Class II, III, or IV symptoms in the absence of severely reduced left ventricular function (ejection fraction < 30%) and/or end-systolic dimension > 55 mm • Asymptomatic adult with chronic severe MR with mildly to moderately reduced left ventricular function (ejection fraction between 30% and 60%, and/or endsystolic dimension ≥ 40 mm).


Aortic Valve Bicuspid Aortic Valve Biscuspid aortic valve (BAV) is defined by the presence of complete or partial fusion of two aortic leaflets, often manifesting as right and left leaflet fusion, otherwise as right and noncoronary cusp fusion, or as left and noncoronary cusp fusion.31 While right and left leaflet fusion is more often associated with stenosis/regurgitation requiring early intervention, the right leaflet and noncoronary cusp fusion is more likely to be associated with aortic root dilatation.100–102 The cusp size may be unequal due to fusion of two cusps leading to one larger cusp. A central raphe may divide the larger of the two cusps at the site of congenital fusion of two parts of the conjoined cusps. Although many adults are previously diagnosed with a bicuspid aortic valve because of a heart murmur, in others the diagnosis is first made when they acquire endocarditis and present with acute severe aortic regurgitation due to aortic leaflet destruction or perforation, leading to heart failure. Secondary infection of the mitral valve due to contiguous spread of the infection is known to occur. Destruction of the infected valves causes regurgitation and the vegetations increase the risk of embolic stroke. Sepsis is common in this scenario. Siniawski et al reported high mortality (approximately 29%) in adults who have endocarditis with aortic ring abscess and secondary infection of the mitral valve requiring double valve surgery. According to their study, the most potent independent risk factors for mortality were septic shock and severe aortic root destruction.103 First-degree relatives of patients with bicuspid aortic valve should be screened by echocardiography for the presence of a bicuspid aortic valve, since familial reoccurrence of bicuspid aortic valve is approximately 9%, mostly likely due to an autosomal dominant pattern of inheritance with reduced penetrance.104 Severe calcification or regurgitation can be present in third or fourth decade, often accelerated by risk factors such as hyperlipidemia. The calcification and fibrosis primarily occurs at the raphe and base of the cusps.105 Aortic regurgitation may result from inability of the leaflets to coapt due to aortic root dilatation and loss of the sinotubular junction, retraction of the leaflets caused by fibrosis, prolapse of aortic cusps, aortic valve attempting to close a perimembranous VSD (“venturi effect”), or following endocarditis due to extensive valve destruction.

1821

Aortic root dilatation is commonly seen in adults with bicuspid aortic valve and they are at least a ninefold greater risk for aortic dissection.106

Echocardiography In the transthoracic parasternal long-axis view, doming of the bicuspid aortic valve leaflets in systole can be appreciated in most young adults who are unlikely to have distorted dysplastic valve or restricted mobility due to calcification of the valve. The parasternal short-axis view (at the aortic valve level), is the best view for defining valve anatomy by showing fusion between two cusps (one smaller and one larger) or a variation of it. The extent of commissural fusion determines degree of stenosis or obstruction. In this view, the open bicuspid aortic valve appears to look like an elliptical “American football” or “fish-mouth” opening (Fig. 75.17). Two-dimensional echocardiography and continuous wave Doppler are routinely used to determine the severity of valve stenosis using the same criteria as in the general population, defined by the ACC/AHA valvular heart disease guidelines.99 The peak aortic velocity should be assessed by continuous wave by Doppler echocardiography in multiple views and the highest values should be recorded (usually best captured in the suprasternal views). The peak and mean gradients are derived accordingly. Since the

Fig. 75.17: Diagrammatic representation of the echocardiographic parasternal short-axis views showing morphological features of the (1) closed normal trileaflet (Mercedes Benz sign) aortic valve as seen on a transesophageal echocardiogram, and (2) an open bicuspid (American foot ball), (3) open unicuspid (tear drop) (a) unicommissural, (b) acommissural (4) a closed quadricuspid (X-sign) aortic valve as seen on transthoracic parasternal short-axis views.

1822


peak instantaneous aortic valve gradient may overestimate the severity of stenosis, the mean gradient is preferred. It correlates more closely with the peak-to-peak gradient traditionally measured during cardiac catheterization. The more universally accepted grading system is the following: mild—valve area > 1.5 cm2, mean gradient < 25 mm Hg, or jet velocity < 3.0 m/s; moderate—valve area 1.0–1.5 cm2, mean gradient 25–40 mm Hg, or jet velocity 3.0–4.0 m/s; or severe—valve area < 1.0 cm2, mean gradient > 40 mm Hg, or jet velocity > 4.0 m/s. Aortic regurgitation is quantified as mild, moderate, or severe, according to the American Society of Echocardiography criteria using standard methods as in acquired valve disease.107 Aortic regurgitation may be evaluated by color Doppler in the parasternal long-axis, short-axis, apical four-chamber, and five-chamber views. The rate of deceleration of the velocity signal of aortic regurgitation, the presence of retrograde flow (diastolic flow reversal) in the proximal descending/abdominal aorta on continuous wave Doppler echocardiography, and the ratio of proximal jet area to left ventricular outflow tract area in combination with the ratio of jet height to left ventricular outflow tract height allow assessment of the severity of aortic regurgitation. The left ventricular size, function, and mass are assessed on serial echocardiograms and are important criteria in determining the need for surgery and long-term clinical outcomes. Associated defects include coarctation of the aorta, VSD, PDA, subaortic stenosis, and parachute mitral valve.31 Intrinsic structural abnormalities of the aortic wall can lead to aortic root dilatation that can in turn progress to an aneurysm that carries risk of dissection five- to ninefold higher than in the general population.106 Other contributory factors for increase in aortic diameters are worsening aortic regurgitation, high body surface area, and advancing age.108,109 In the parasternal long-axis view, the aortic root should be routinely measured in systole, from leading edge to leading edge, at the levels of the annulus, midsinus level, sinotubular junction, and the proximal aorta.108 It is important to report these measurements in all the cases, since progressive aortic dilatation may occur in this population even in the absence of significant aortic stenosis and regurgitation. Depending upon the size of the aorta, imaging should be performed every other year if the maximum dimensions are < 40 mm, and performed annually if they are ≥ 40 mm. Unfortunately, replacement of the bicuspid aortic valve has not been shown to reduce the risk of further dilatation.

Three-dimensional echocardiography is useful in defining the morphology of the aortic valve. In adults with good quality transthoracic images, it may define thickening or redundancy of the aortic valve leaflets with multiple folds. It also helps in identifying vegetations and localizing perforations.110 Another variant of congenital aortic valve defects is the unicuspid aortic valve, described as a single commissure with two poorly developed cusps. The short-axis view of the aortic valve clinches the diagnosis on TTE or TEE. During diastole, the raphae may look like true commissures giving it the “Mercedes Benz” sign appearance of a trileaflet aortic valve. During systole, there is no cusp separation, and the unicuspid valve looks like a “teardrop” with an eccentric opening (Fig. 75.17). The more common type of unicuspid aortic valve is unicommissural and the other one, acommissural (with a lateral attachment to the aorta at the level of the orifice). The origin of the coronaries should be normal due to normal development of the sinuses of Valsalva in these individuals.111,112 In even rarer cases, there is development of an extra commissure during valvulogenesis, resulting in a quadricuspid aortic valve. On transthoracic echocardiography and more confidently with a TEE, it is best identified in the short-axis view at the level of the aortic valve during diastole, when it appears like an “X” sign (Fig. 75.17). The 3D echocardiogram defines the anatomy of the four cusps more clearly.113 Like the BAV, all other congenital malformations of the aortic valve are prone to an increased rate of calcification and fibrosis leading to significant stenosis and/or regurgitation, thereby requiring aortic valve replacement.114 They are also associated with aortic root dilation in majority of the cases. The risk of aortic dissection is 18-fold more in individuals with a unicuspid aortic valve.106 A synopsis of echocardiographic assessment of the bicuspid aortic valve is reviewed in Table 75.12.

Cardiac Catheterization Cardiac catheterization is recommended for assessment of coronary arteries before aortic valve surgery in adults who are at risk for coronary artery disease. It is also recommended when a pulmonary autograft (Ross operation) is being considered, so that the origin of the coronary arteries can be defined in case CTA/MRI are not being performed. It is of incremental value when there is


1823

Table 75.12: Bicuspid Aortic Valve


Coarctation of aorta

•

Aortic root dilatation/aneurysm or dissection

•

Subaortic and supravalvular (aortic) stenosis

•



Type of valve—fusion of raphe

•

Valve annulus

•

Thickness of the leaflets

•

Gradient—degree of stenosis

•

Concomitant aortic regurgitation

•

Aortic root dimensions—dilatation or aneurysm

•

Subaortic obstruction/hypertrophy—left ventricular outflow tract gradient

•

Left ventricular size mass and function

Postoperative •

Assessment of valve gradient

•

Grading aortic valve regurgitation/paravalvular leak

•

Aortic root dimensions to rule out dilatation/aneurysm or dissection

a discrepancy between symptoms and echocardiographic findings. Most adults will require aortic valve replacement. Catheter-based percutaneous balloon valvuloplasty is a possibility in a young adult with an isolated severe aortic stenosis and noncalcified pliable valves, or it may offer temporary relief in a markedly symptomatic pregnant woman with severe stenosis refractory to medical management during late second or third trimesters. The ACC/AHA Class I indications for aortic valvotomy in adolescents and young adults are the following:99 • Symptoms such as angina, syncope, or dyspnea on exertion with a left ventricular peak-to-peak gradient across the aortic valve of 50 mm Hg or higher in the absence of heavy calcification, on cardiac catheterization • Asymptomatic patient with a left ventricular peak-topeak gradient across the aortic valve > 60 mm Hg on cardiac catheterization • Asymptomatic patient with ECG changes (ST or T-wave changes over the left precordium) at rest or with exercise and left ventricular peak-to-aortic valve gradient > 50 mm Hg.

Magnetic Resonance Imaging/Computed Tomography The aortic root, arch, and the descending thoracic aorta should be evaluated by either of these imaging modalities prior to aortic valve replacement or when echocardiography is suspicious for an enlarging aneurysm.

Stress Testing Although stress testing with exercise may be performed cautiously to assess functional capacity and blood pressure response in asymptomatic adults who do not have critical stenosis, it is contraindicated in symptomatic adults, in those with repolarization abnormalities on ECG, or systolic dysfunction on echocardiography. Dobutamine stress testing can be performed judiciously in adults with low-gradient aortic stenosis in the setting of low left ventricular ejection fraction, since the low cardiac output may mask a higher grade of stenosis. The ACC/AHA Class I indications for aortic valve replacement are the following:3

1824


Aortic Stenosis: • Severe aortic stenosis or chronic severe regurgitation in an adult undergoing coronary artery bypass graft surgery or any other cardiac surgery of the aorta or concomitant defect • Severe aortic stenosis with left ventricular function < 50% • Symptomatic severe aortic regurgitation with left ventricular ejection fraction < 50% and left ventricular dilatation • Aortic root surgery is indicated when the ascending aorta diameter is ≥ 5.0 cm or when it is increasing by 5 mm or more per year. Aortic Regurgitation: • Symptomatic (angina, syncope, or dyspnea on exertion) chronic severe aortic regurgitation • Asymptomatic adult with chronic severe aortic regurgitation with reduced systolic function (ejection fraction < 50% confirmed on two echocardiograms (1–3 months apart) • Asymptomatic chronic severe aortic regurgitation with progressive left ventricular enlargement (end-diastolic dimension > 4 standard deviations above normal) should receive aortic valve repair or replacement.

The Postoperative Adult Echocardiography is useful for follow-up of prosthetic valve function, left ventricular size and function, aortic root dimensions, and for estimating right ventricular systolic pressures postoperatively. The aortic root dimensions need long-term follow-up, since significant enlargement of the ascending aorta with aneurysm formation and dissection continues even after valve replacement.104 When aortic root replacement with coronary reimplantation is performed, there is a risk of coronary ostial obstruction. Potential prosthetic valve complications include periprosthetic regurgitation with or without hemolysis, obstruction related to pannus or thrombosis, and endocarditis.

Subaortic Stenosis Subaortic stenosis is a congenital obstruction below the aortic valve that may present as a discrete “shelf-like” fibrous ring or as a fibromuscular “tunnel-type” defect causing a “fixed” left ventricular outflow tract obstruction below the aortic valve.31

Although it usually presents as an isolated defect, the subaortic fibrous ring may extend onto the anterior mitral leaflet, accessory mitral tissue, or anomalous chords causing subaortic aortic stenosis. It is often associated with a perimembranous VSD or an atrioventricular ventricular septal defect. Also, it may become more visible after ventricular septal patch closure. Long-term residua and sequelae include progressive aortic valve damage and aortic regurgitation due to increased turbulence in the subaortic left ventricular outflow tract, in more than half the cases. Increasing ventricular hypertrophy due to pressure overload eventually leads to impaired left ventricular function. These adults are also at risk for infective endocarditis and sudden cardiac death.115,116

Echocardiography Subaortic stenosis is best seen in the parasternal long-axis view that delineates the left ventricular out flow tract with the transducer positions perpendicular to the membrane. The left ventricular outflow tract (LVOT) obstruction is examined carefully with color flow Doppler, since the obstruction may present at multiple levels. Aortic regurgitation may occur due to long-standing subaortic flow disturbance. In most adults, 2D transthoracic echocardiography defines the anatomy of the subaortic stenosis, the dimensions of the ascending aorta, adjacent mitral valve involvement, degree of left ventricular hypertrophy, and function (both systolic and diastolic). Sometimes a thin, wispy, discrete fibrous subaortic ring may not be clearly visible on transthoracic echocardiography. Doppler helps in estimating the degree of aortic valve regurgitation. The severity of the gradient across the left ventricular outflow tract and the aortic valve can be determined by continuous wave Doppler (Fig. 75.18). The location of a VSD has an impact in the estimating of the severity of subaortic stenosis. The degree of subaortic stenosis may be underestimated when the VSD is proximal to subaortic obstruction and overestimated when it is distal to it. As in the case of aortic stenosis, reduced left ventricular systolic function will also lead to underestimation of the gradient. Among the factors affecting progression of the left ventricular outflow tract obstruction are the position of the membrane adjacent to the aortic valve and whether it extends toward the mitral valve.


1825

End-hole or micromanometer-tipped catheters are required for confirming the left ventricular outflow tract gradient accurately. Timely surgery is important, since it may be able to reduce the progression of left ventricular hypertrophy and aortic regurgitation.

Surgical Resection of Subaortic Stenosis

Fig. 75.18: Continuous wave Doppler showing the severity of the gradient across the left ventricular outflow tract with Valsalva maneuver in a patient with subaortic stenosis.

Transesophageal Echocardiography TEE is useful preoperatively and intraoperatively, in adults with limited acoustic windows, to define the morphology of the subaortic stenosis, and assess associated defects. Intraoperative TEE evaluates adequate resection of the subaortic membrane or ridge and rules out residual aortic regurgitation. It also confirms the absence of iatrogenic damage to the anterior mitral valve leaflet or creation of a VSD by aggressive resection of the membrane. Similarly, 3D echocardiography may further define left ventricular outflow anatomy.

Exercise Stress Testing Stress echocardiography is used to determine any increase in gradient with exercise in symptomatic adults with a peak gradient < 50 mm Hg.

Magnetic Resonance Imaging/Computed Tomography In adults with limited acoustic windows who are unable to undergo a TEE, an MRI or CTA plays an important role in defining the anatomy and associated defects.

Cardiac Catheterization Preoperatively, cardiac catheterization is performed in adults who are at high risk for coronary artery disease.

The ACC/AHA Class I indications for surgical intervention in adults with subaortic stenosis are the following:3 • Severe obstruction with peak instantaneous gradient > 50 mm Hg or a mean gradient > 30 mm Hg • Progressive aortic regurgitation with a left ventricular end-systolic diameter of 50 mm or more or a left ventricular ejection fraction < 55%.

The Postoperative Adult The left ventricular outflow tract should to be assessed with 2D transthoracic echocardiography and Doppler in the parasternal long-axis and apical four-chamber views, to rule out recurrence of subaortic stenosis or progression of aortic regurgitation. The postoperative residua and sequelae in an adult with discrete “shelf-like” fibrous ring are iatrogenic VSD, aortic and mitral regurgitation due to extensive resection of interventricular septum, and injury to the mitral valve. Pacemaker wires may be seen in the right heart chambers of those who suffered a conduction system injury during surgery.

Supravalvular Aortic Stenosis In adults, supravalvular stenosis may present with hypertension or symptoms suggestive of ischemia. In this defect, there is a fixed obstruction extending from below the sinotubular junction distally into the aortic root. Even though the obstruction usually occurs distal to the origin of the coronary arteries, there may be ischemia due to limited diastolic flow in adults with high systolic pressures that also cause left ventricular hypertrophy. In some adults, there may be coronary ostial obstruction (partial or complete) or abnormalities of the coronaries such as ectasia.117 In children with Williams syndrome, supravalvular stenosis is the most common congenital heart defect. Associated defects include peripheral pulmonary artery stenosis and hypoplastic aorta.31

1826


Echocardiography The left ventricular size, mass, systolic, and diastolic function should be assessed on serial echocardiograms in adults with supravalvular aortic stenosis. In most adults, the parasternal long-axis view demonstrates the morphology of the aortic root and allows measurement of the diameter at the levels of the annulus, midsinus, sinotubular junction, and the ascending aorta 2 cm distal to the sinotubular junction. In others, the tubular portion of the aorta is not well visualized and the best views are the suprasternal or high right parasternal views. Increased continuous wave Doppler gradient across an anatomically normal aortic valve should alert the echocardiographer about a possible obstruction. Pressure recovery phenomenon may be seen in adults with long-segment or tubular stenosis. Transesophageal echocardiography is useful in obtaining this information in adults with limited acoustic windows on transthoracic echocardiography. It also defines the origins of the coronary arteries.

Stress Echocardiography In adults presenting with symptoms and signs suggestive of ischemia, stress echocardiography can be performed to assess for coronary involvement and evaluation of the gradient across the stenosis before and after exercise.

Magnetic Resonance Imaging/Computed Tomography Extracardiac structures—aorta, pulmonary artery, and its branches, coronaries as well as the left ventricular outflow tract are best delineated by MRI/CTA. In Williams syndrome, the entire aorta and the renal arteries should be imaged to look for peripheral stenosis.

Cardiac Catheterization For definitive diagnosis of coronary involvement and for accurately measuring the gradient across the supravalvular stenosis, angiography is the preferred diagnostic imaging modality.

Surgery for Supravalvular Stenosis The ACC/AHA Class I recommendations for surgical treatment for adults with supravalvular stenosis are the following:

•

•

Symptomatic supravalvular stenosis with Doppler echocardiography demonstrating a peak (instantaneous) gradient > 70 mm Hg and a mean gradient over 50 mm Hg Significant symptoms such as angina, dyspnea, or syncope in the setting of left ventricular hypertrophy and/or impaired left ventricular function.

The Postoperative Adult Long-term follow-up is required to assess left ventricular outflow tract obstruction, left ventricular mass/function, and aortic and mitral regurgitation. There is a lifelong risk of coronary involvement, left ventricular hypertrophy, and diastolic dysfunction due to hypertension. Adults with previous patch repair of the hypoplastic aorta are at risk of aneurysm formation at the site of patch repair.

COMPLEX CONGENITAL HEART DEFECTS Complex defects are those that usually present as a group of anomalies centered around a major condition.

Coarctation of Aorta Coarctation of aorta (COA) is discrete or segmental narrowing of the aorta below the origin of the left subclavian artery, at the junction of the distal aortic arch, and the descending aorta (in most cases) or its variation.31 It is appears more likely to be a diffuse arteriopathy with associated structural abnormalities of the great arterial walls that are not just limited to focal stenosis. Hence, it is no longer considered as a “simple” defect.118 The commonest associated defects are a bicuspid aortic valve followed by mitral valve disease. These individuals are also prone to aortic root dilatation. Prior to the era of surgeries or interventions, the survival was only 50% by 32 years of age.119 While many individuals are operated in childhood in the present era, some are still diagnosed in adulthood during an evaluation for secondary hypertension.120 Despite relief of stenosis by surgery or catheter-based intervention, adults have long-term residua, sequelae, increased morbidity, and reduced life spans. The most common issue is ambulatory hypertension and significant left ventricular hypertrophy seen on an ECG or an echocardiogram. Despite successful COA repair, recurrence at the site of


stenosis (recoarctation) or aneurysmal dilatation at the site of repair are not uncommon. If left uncorrected, these are associated with high morbidity and mortality. Aneurysms are most often seen at the site of coarctation repair but may involve the descending thoracic aorta and the distal aortic arch.121 Predictors of aneurysmal formation at the site of coarctation repair include the use of the patch graft technique and late correction of coarctation. Endto-end repair of COA is associated with the lowest risk of aneurysmal formation at the site of repair. Adults with a bicuspid aortic valve who have high preoperative pressure gradients are at higher risk of having an aneurysm of the ascending aorta, especially following late repair of COA. Aortic root aneurysms are also associated with morbidity and mortality due to a high prevalence of severe aortic regurgitation, dissection, and rupture.122 Another site for aneurysm rupture is in the circle of Willis. Adults with COA have been noted to have a higher prevalence of premature coronary artery disease. A recent study points out that COA lesion alone does not predispose to premature coronary artery disease.123 Hypertension, vascular, and endothelial factors are more likely the associated culprits.

Echocardiography Two-dimensional echocardiography is highly specific in diagnosing aortic arch obstruction.124 The aortic arch should be first interrogated carefully by 2D echocardiography with pulsed Doppler recording, under direct visualization. On transthoracic echocardiography, the coarctation is best seen in the suprasternal or high right parasternal views, also allowing visualization of the aortic arch and proximal descending aorta. Presence of color flow Doppler turbulence in the aortic arch brings to our attention the maximum site of narrowing. Continuous wave spectral Doppler interrogation is used to assess the gradient. It shows characteristic flow profile with an increased systolic flow velocity and continuous gradient of forward diastolic flow. The more accurate formula for estimating the pressure gradient is 4(V2-V1)2 with V1 being the velocity proximal to the coarctation and V2 being the peak velocity at the site of maximal narrowing. This formula avoids inaccurate reports of high pressure gradients obtained by the simplified Bernoulli equation (4V2) in patients with long tubular narrowing of the aortic arch.125 A peak gradient of over 20 mm Hg indicates a significant obstruction. However, the gradient may be low or negligible if there are collaterals or ductal flow.

1827

Marx et al. had noted that the major pitfall of echocardiography in COA was due to the significant collateral flow resulting in the failure to record an accurate Doppler gradient.125 In the absence of collateral flow, Therrien et al. reported that echocardiography was a suitable screening test with a sensitivity of 87%.126 Limited visualization of the aortic arch has been another issue with transthoracic echocardiography. An abnormal Doppler flow pattern may also be noted in the abdominal aorta, with decreased pulsatility and absence of early diastolic flow reversal. The abdominal aortic Doppler profile will not show diastolic flow reversal in such patients without a discrete obstructive lesion. Conversely, it is a useful technique for screening an obscure obstruction of significance that will manifest by delayed systolic upstroke, diastolic flow reversal (antegrade flow), and turbulence during systole on color/spectral Doppler examination of the upper abdominal aorta. Abnormal flow in collateral vessels can be detected by color flow and pulsed wave Doppler. Adults with coarctation often have a bicuspid aortic valve and aortic root dilatation. Therefore, it is important to measure the transverse dimensions at the level of the aortic annulus, aortic sinuses, sinotubular junction, and approximately 2 cm distally in the ascending aorta. Due to long-standing hypertension and multiple factors, many adults are prone to hypertensive heart disease and need assessment of left ventricular size, mass (left ventricular hypertrophy), systolic, and diastolic function. Other associated defects are ventricular septal defects, subaortic stenosis, patent ductus arteriosus, and mitral valve disorder (supramitral ring). A synopsis of the echocardiographic assessment of coarctation of aorta is reviewed in Table 75.13.

Transesophageal Echocardiography Agrawal et al. showed the incremental value of TEE in delineating the aortic arch branches. Their protocol can be adapted for the multiplane TEE probe.127 The short-axis view of the proximal descending aorta is first identified as a circular cavity in the transverse plane in the midthoracic level. Further withdrawal of the probe brings the aortic arch into view with the loss of the circular configuration transitioning into a horizontal tube-like structure. Switching from the transverse to the longitudinal plane (90°) demonstrates all three vessels (Fig. 75.1). The longitudinal cut of the aortic arch makes it appear circular or ovoid. Small movements of the probe (rotation, movement,

1828


Table 75.13: Coarctation of the Aorta


Bicuspid aortic valve

•


•

Patent ductus arteriosus

•

Left heart obstructive lesions—subaortic stenosis, mitral stenosis

•

Aortic root/arch dilatation or aneurysm


Aortic arch anatomy—rule out aneurysm

•

Aortic arch gradient

•

Assessment of associated defects

•

Left ventricular hypertrophy

•

Left ventricular function

•

Stress echocardiography for evaluation of ambulatory hypertension and coronary ischemia

Postoperative •

Rule out recoarctation or aneurysm at the site of the surgery (especially with patch repair)

•

Left ventricular hypertrophy (hypertension usually persists despite surgical relief of the coarctation)

•


•

Stress echocardiography for evaluation of ambulatory hypertension and coronary ischemia

and angulation) allow visualization of the aortic arch. Clockwise rotation of the probe moves the vertical plane to the right bringing the innominate artery into view as the most anterior vessel, while counterclockwise rotation moves it to the left, and reveals the left carotid and the left subclavian arteries more posteriorly.127 The X-plane view (Philips Echocardiography System) allows simultaneous views of the transverse and longitudinal planes.

Treadmill Stress Testing Treadmill stress testing plays a very important role in determining the maximum exercise systolic blood pressure, which is a predictor for chronic hypertension in adults with COA.128 Antihypertensive therapy can then be started in a timely manner. Adults with COA may have normal blood pressure during office visits and treadmill stress testing unmasks the ambulatory hypertension in response to exercise that they may be experiencing in their daily lives. It also allows assessment of functional capacity, exercise-induced arrhythmias, and ischemia. Depending upon its availability, cardiopulmonary exercise testing (CPET) may hold a promise by using exercise parameters that may assist in early identification

of nonhypertensive patients with COA who are at increased risk of developing of arterial hypertension.129

Stress Echocardiography Stress echocardiography with color and continuous wave Doppler from the suprasternal notch allows assessment of the coarctation gradient at rest and following exercise, in addition to providing information obtained by the treadmill stress testing. Coronary artery disease occurs prematurely in this population, especially in those with uncontrolled ambulatory hypertension.

Magnetic Resonance Imaging/Computed Tomography MRI is the diagnostic test of choice for complete evaluation of the coarctation of aorta due to limitations of echocardiography, especially TEE (because of the perpendicular plane of the Doppler in relation to the obstructive lesion).126 In patients undergoing surgery, preoperative MRI/ MRA or CT angiography with 3D reconstruction allows precise identification of the location, anatomy of the coarctation, and the entire aorta along with the collaterals.


MRI is useful for defining the morphology, delineating aneurysms in postoperative cases, site of the stenosis, extent and degree of narrowing, aortic arch anatomy, and aortopulmonary collaterals. Most importantly, MRI provides hemodynamic data with calculation of the pressure gradient across the stenosis. CTA is another preferred imaging modality for imaging the area of coarctation and for obtaining extracardiac information in an adult with a pacemaker or defibrillator. Within a short acquisition time, simultaneous visualization of the ascending aorta, aortic arch, descending aorta, aortic valve, course of the coronary arteries, coronary anomalies and calcium risk score can be obtained.130 Magnetic resonance angiography (MRA) is performed every 5 years to search for aneurysms of the intracranial arteries, since intracranial aneurysms may occur even in normotensive adults.131 MRA screening has reported intracranial aneurysms in approximately 10% of the patients with COA.132 Martin et al. reported a case of a young woman with severe COA presenting and subarachnoid hemorrhage.133 Evaluation of the repair site by MRI/CT should be performed at intervals of 5 years or less, depending on the specific anatomical findings before and after repair.

Cardiac Catheterization Coronary artery disease should be ruled out in adults prior to surgery. Stent implantation is the preferred intervention compared to balloon angioplasty alone for coarctation of aorta in adults, with persistent relief of stenosis and lower incidence of aneurysm formation.

Surgery or Intervention for Coarctation of Aorta The ACC/AHA Class I recommendations for interventional and surgical treatment of coarctation of the aorta in adults are the following:3 • Peak-to-peak coarctation gradient ≥ 20 mm Hg • Peak-to-peak coarctation gradient < 20 mm Hg when an imaging study shows direct evidence of significant coarctation with radiological evidence of significant collateral flow. In addition, the presence of a large aortic root, arch aneurysm, or severe degree of associated defects may also prompt early intervention/surgery. Catheter-based intervention is the preferred alternative to surgery for recurrent aortic coarctation

1829

following surgical repair in the absence of aneurysm/ pseudoaneurysm formation, complex coarctation affecting the adjoining arch arterial branches, or need for concomitant surgery (for aortic valve or aortic root).

The Postoperative Adult Recurrence of narrowing at the coarctation site can occur in adulthood. Aneurysm formation at the repair site occurs in some adults after Dacron patch aortoplasty or following resection of the coarctation. Some individuals many have pseudoaneurysms while in others, there is a risk of dissection around the site of repair due to intrinsic structural abnormalities of the aorta. Doppler echocardiography, guided by transthoracic 2D images, is useful for follow-up after successful stenting of the coarctation site reflected by a significant decrease in peak systolic pressure gradient. Other promising parameters that may find more widespread use in the future include diastolic velocity, diastolic velocity halftime index, and diastolic pressure half-time index.134

Tetralogy of Fallot Four defects make the tetralogy of Fallot (TOF)—a VSD, an aorta that overrides the large ventricular septal defect (by < 50% of its diameter), subpulmonary infundibular stenosis, and right ventricular hypertrophy. The presence of an ASD would make it the “pentalogy of Fallot”!31 The clinical presentation is affected by the variable degree of right ventricular outflow tract obstruction. The most extreme form is pulmonary atresia with a VSD. Associated defects are common and include abnormal or absent pulmonary valve, pulmonary artery anomalies (dilated or hypoplastic), aortic root dilation, aortic regurgitation, right aortic arch (approximately 20–30%), and abnormal origin of the coronary (left anterior descending coronary artery arising from the right coronary artery and crossing the right ventricular outflow tract). Most adults have had previous palliative shunts or complete intracardiac repair but continue to present with multiple residua and sequelae. The intracardiac repair comprises closure of the VSD with redirection of the aorta toward the left ventricle, and resection of the right ventricular outflow tract obstruction with relief of hypertrophied muscle that is contributing to infundibular stenosis. Following an intracardiac repair of TOF, the most common long-term cardiac issue is chronic pulmonary valve regurgitation that requires reoperations (pulmonary valve replacement), approximately every 10 to 20 years.

1830


Adults with pulmonary regurgitation (due to an absent pulmonary valve or other pulmonary valve abnormalities) who did not undergo pulmonary valve replacement during their growing years, also present with progressive pulmonary regurgitation. Those with absent pulmonary valve also have massive enlargement of the pulmonary arteries with severe pulmonary regurgitation. Some other factors exacerbating pulmonary regurgitation in this population that can be assessed echocardiographically are the following: pulmonary annulus size, peripheral pulmonary artery stenosis, residual shunts (atrial and ventricular septal defects), pulmonary hypertension, and right ventricular diastolic dysfunction. Progressive pulmonary regurgitation leads to right ventricular enlargement, impaired right ventricular function (systolic and diastolic), and increasing tricuspid regurgitation and right atrial enlargement. The clinical impact of these is variable and different patients will present with varying degrees of decreased exercise tolerance, dyspnea on exertion, and predisposition to atrial/ventricular arrhythmias. In a multicenter study, we reported that symptoms related to pulmonary regurgitation may be well tolerated over a long period; progressively increasing from the beginning of the fourth decade with more than half the adults becoming symptomatic in the following two decades.135 Besides pulmonary regurgitation, other factors contributing to right ventricular enlargement and impaired function are the degree of tricuspid regurgitation, pulmonary hypertension, residual shunts, and distortion of the shape of the right ventricle. The dilated right ventricle may exhibit improved ejection fraction temporarily in response to volume overload before spiraling down with further decrease in myocardial contractility. Left ventricular dilatation, decreased contractility, increased myocardial stiffness, and impaired function occurs over time following intracardiac repair of TOF.136 The left ventricular size and function is impacted specifically by the severity of aortic regurgitation due to inadequate coaptation of the aortic leaflets as a result of aortic root dilatation. Due to interventricular dependence, the deteriorating right ventricular function adversely impacts the left ventricular performance. For both the ventricles, the timing of palliative shunts and definitive intracardiac repair affects myocardial contractility. Prolonged cyanosis, inadequate myocardial preservation during surgeries involving cardiopulmonary bypass, and pressure and volume overload have deleterious effects on the myocardium predisposing it to fibrosis.

Pulmonary regurgitation and right ventricular outflow aneurysm/akinesia are independently associated with right ventricular dilatation, leading to hypertrophy and reduced function over time. It is, therefore, mandatory to restore pulmonary valve function and avoid RVOT aneurysm/akinesia in order to preserve biventricular function.137 Concomitant defects such as atrial or ventricular septal defect may present with residual patch leaks on Doppler interrogation. Although aortic root dilation is fairly common in adults with tetralogy of Fallot, aortic dissection has only been reported in rare instances in the published literature. In these reports, it invariably occurred with markedly severe aortic root dilatation, with aortic dimensions varying between 7 and 9.3 cm.138–140 So far, the aortic arch sidedness has not been proven to have an independent association with the degree of aortic root dilatation. In addition to the hemodynamic effects, severe pulmonary regurgitation exacerbates the scar tissue at the site of the RVOT patch aneurysm, making it a nidus for generation of monomorphic ventricular tachycardia.141 Pulmonary atresia with ventricular septal defect represents the severest form of right ventricular outflow tract obstruction. Surgical repairs are accordingly more complex, involving unifocalization of the multiple aortopulmonary collaterals into right and left conduit that are then connected to the right ventricle to pulmonary artery (RV to PA) conduit, to mimic the main pulmonary artery and its branches (Fig. 75.19).

Echocardiography A comprehensive transthoracic echocardiographic evaluation in an adult with tetralogy of Fallot postintracardiac repair begins with the assessment of the right and left ventricular size and function. Left ventricular function is estimated by standard methods. Besides the standard measures for assessing left ventricular function, a Doppler-derived index of LV filling pressure (the ratio of early transmitral flow velocity to early diastolic mitral annular velocity) is a powerful predictor of ventricular arrhythmias.142 Right ventricular enlargement and declining systolic/ diastolic function are common especially in the setting of progressive pulmonary regurgitation. The enlarging right ventricle stretches the tricuspid annulus causing progressive tricuspid regurgitation, followed by right atrial


1831

independent parameter for right ventricular function is myocardial acceleration during isovolumetric contraction, a Doppler-based index, described by Frigiola et al.148 The isovolumic acceleration index is calculated by dividing the myocardial velocity during isovolumic contraction by the time interval from the onset of the acceleration to the time at peak velocity. It allows early detection of impaired ventricular function due to the detrimental effect of pulmonary regurgitation before the onset of symptoms.148 While qualitative assessment by experienced readers continues to be a practical solution for serial followups, 3D quantification of right ventricular function with speckle tracking is gaining popularity. In a study by Gopal et al, 3D echocardiographic techniques have been shown to correlate closely with MRI-derived right ventricular end-diastolic volume and could reduce the need for MRI in some patients.149

Fig. 75.19: Diagrammatic representation of the surgical repair in pulmonary atresia with ventricular septal defect. Unifocalization of the multiple aortopulmonary collateral arteries (MAPCAs) into right and left conduits is performed, that are then connected to the main right ventricle to pulmonary artery (RV to PA) conduit, to mimic the main pulmonary artery and its branches. (LV: Left ventricle; RV: Right ventricle; VSD: Ventricular septal defect). (Inspired by an operation note sketch by Dr Hillel Laks).

enlargement. The right ventricular systolic pressure is estimated from the tricuspid regurgitant jet velocity. Some adults may have a residual right ventricular outflow tract obstruction contributing to right ventricular hypertrophy, while others may have an aneurysm of the right ventricular outflow tract. Right ventricular size and systolic function: The shape of the right ventricle, trabeculations, and distortion due to previous surgeries involving the outflow tract have made accurate quantification very challenging. Transthoracic echocardiography is limited in visualizing the right ventricular outflow tract for identifying aneurysm that along with right ventricular dilatation have a major impact on the clinical status of those operated for tetralogy of Fallot in the presence of pulmonary regurgitation. In addition, changes in loading conditions may affect some of the measurements obtained by using echocardiographic parameters such as the Tei index,143,144 stress and strain rate imaging,145 and instantaneous rate of pressure increase (dP/dt) by Doppler assessment.146,147 A relatively load-

Right ventricular diastolic function: Isolated right ventricular restriction late after tetralogy of Fallot repair is fairly common. Methods for assessment of right ventricular diastolic function and restrictive physiology have been of major research interest. The clinical applications of these time-consuming protocols have been limited so far due to difficulty in accurately using them on the distorted right ventricular anatomy. Gatzoulis et al. showed that antegrade diastolic flow in the main pulmonary artery, coinciding with atrial systole (A-wave) throughout the respiratory cycle was indicative of right ventricular restriction. On pulsed Doppler sampling (at the midpoint between the pulmonary valve leaflets and bifurcation of the main pulmonary artery), the duration of pulmonary regurgitation was noted to be shorter in those with right ventricular restriction. This finding was thought to be reflective of reduced right ventricular diastolic compliance, with restrictive physiology at end-diastole, thereby making the right ventricle a passive conduit between right atrium and pulmonary artery during atrial systole.150 However, it can also be present in normal hearts during inspiration. Therefore, it should be recorded for at least five consecutive beats to be of diagnostic value in identifying reduced right ventricular diastolic compliance. Other features on pulsed Doppler that support restrictive physiology include: Superior vena caval flow reversal with atrial systole (measured 1–2 cm proximal to the right atrium), and shorter inspiratory and expiratory transtricuspid E-wave deceleration times (measured at the level of the tricuspid valve leaflets).

1832


Pulmonary valve regurgitation/stenosis: While some adults may have residual pulmonary stenosis that needs attention for its etiology, location, and severity, the most common issue in this population is pulmonary regurgitation. The best view for assessment of pulmonary regurgitation is the parasternal short-axis view at the level of the great arteries. This view can be modified to evaluate the proximal conduit, the main and branch pulmonary arteries. Color and pulsed Doppler are used to evaluate: (a) width of the regurgitant jet at the level of the pulmonary valve or proximal right ventricular outflow tract (RVOT) conduit/ prosthetic valve; and (b) the degree of flow reversal in the main and branch pulmonary arteries. For assessment of the RVOT conduit, continuous wave Doppler is used to assess maximum velocity and mean gradient across the conduit or a prosthetic valve in the parasternal long-axis views, apical, or subcostal views. Pulmonary regurgitation is graded as trace, mild, moderate, or severe as shown in Table 75.14. Although many other methods have been proposed in recent times for the assessment of pulmonary regurgitation, color Doppler continues to be the first one to bring it to our attention. The regurgitant jet flow can be seen in the right ventricular outflow tract. Retrograde diastolic flow into the main pulmonary artery and its branches may be seen in severe pulmonary regurgitation. Spectral Doppler sample at the level of the pulmonary valve demonstrates normal forward flow in systole and holodiastolic flow reversal due to severe pulmonary regurgitation. A pressure half-time of <100 milliseconds is also a good indicator of severe pulmonary regurgitation.151 However, color Doppler may not be a reliable indicator in low-pressure severe pulmonary regurgitation. In these cases, the pulsations in the right ventricular outflow tract/ main pulmonary artery that often extend into the branches are the surrogate marker. The degree of pulmonary stenosis or residual obstruction at the level of pulmonary valve, infundibulum, or pulmonary artery branches should be estimated using the standard continuous wave Doppler technique. Echocardiographic assessment of palliative shunts: Although most of the adults have undergone intracardiac repair with takedown of the shunt, a few may still have long-standing palliative shunts. The most common shunts are: • Classic Blalock–Taussig–Thomas (BTT) shunt—subclavian to pulmonary artery anastomosis to increase pulmonary blood flow • Modified BTT shunt—subclavian to pulmonary artery anastomosis, using a Gore-tex graft to increase pulmonary blood flow

•

Potts shunt—descending aorta to left pulmonary artery anastomosis to increase pulmonary blood flow • Waterston shunt—ascending aorta to right pulmonary artery anastomosis to increase pulmonary blood flow. These palliative shunts were performed to enhance pulmonary flow in patients with severe right ventricular outflow tract obstruction prior to complete intracardiac repair. Continuous wave Doppler shows nonlaminar blood flow directed from the aorta to pulmonary artery both in systole and diastole. With the larger shunts, pulmonary hypertension may develop over time. When the pulmonary hypertension becomes severe, the diastolic flow ceases; and when pulmonary artery systolic pressure exceeds systemic values, the systolic flow ceases.152 While the orifice of the BTT shunt between the subclavian and pulmonary artery shunt may be seen on a transthoracic echocardiogram, transesophageal echocardiography is required to see the side-to-side connections in Potts and Waterston shunts.152 Aortic root dilation (with loss of the sinotubular junction) is common in tetralogy of Fallot and may contribute to progressive aortic regurgitation due to inadequate coaptation of the aortic leaflets. Aortic root dimensions should, therefore, be measured on serial echocardiograms as discussed in the section on aortic root in adults with congenital heart disease. Color Doppler assists in ruling out residual shunts (ventricular or atrial septal defects). A synopsis of echocardiographic assessment of tetralogy of Fallot is reviewed in Table 75.15.

Stress Echocardiography Exercise testing is required for objective assessment of functional capacity and to unveil exercise-induced arrhythmias such as atrial fibrillation/flutter, premature ventricular complexes, and nonsustained ventricular tachycardia in the postoperative adult with tetralogy of Fallot. Monomorphic ventricular tachycardia most often occurs in the presence of an old ventriculotomy scar. Poor heart rate response to exercise unmasks chronotropic incompetence that may lead to pacemaker implantation. Stress echocardiography provides additional information regarding the severity of pulmonary hypertension postexercise and the impact of pulmonary regurgitation on the right ventricular contractile reserve, by gauging its hyperdynamic response to exercise. Meijboom et al. showed that exercise capacity inversely correlates with right ventricular dilation in patients with repaired tetralogy.153


1833

Table 75.14: Tetralogy of Fallot


Right aortic arch—20% to 30%

•

Pulmonary stenosis

•

Hypoplastic pulmonary arteries

•

Absent pulmonary valve

•

Pulmonary atresia

•

Pulmonary artery dilatation/aneurysm

•


•


•

AV septal defects

•

Muscular ventricular septal defects

•

Anomalous origin of the coronary arteries (left anterior descending arising from right coronary cusp and courses across the right ventricular outflow tract)

•

Aortic root dilatation

•

Aortic regurgitation

•

Subaortic stenosis

•

Aortopulmonary window

•

Aortopulmonary collaterals

•

Absent left pulmonary artery

•

Origin of a pulmonary artery from the aorta

•

Ebstein’s anomaly of the tricuspid valve

•

Anomalous coronaries


Right and left ventricular size and function

•

Right ventricular outflow tract (infundibular) obstruction

•

Pulmonary regurgitation

•

Pulmonary stenosis—at different levels, usually branch stenosis

•


•

Aortic root dilation (loss of the curvature of the sinotubular junction)

•

Shunt lesions—ventricular septal defects, atrial septal defect, patent ductus arteriosus, persistent left superior vena cava

•

Aortic arch anatomy (right aortic arch seen in 20–25%)

•

Origins of the coronary arteries

Postoperative •

Residual VSD or patch leak

•

Pulmonary regurgitation

•

Pulmonary stenosis

•

Right ventricular out flow tract size/aneurysm

•

Aortic root size

•


•


•


1834


Table 75.15: Echocardiographic Grading of Pulmonary Regurgitaiton

A. Based on the Color Doppler width of the jet on the ventricular aspect of pulmonary valve leaflets Trace—a flash of color Mild—jet width < 20% of the annular width of the valve/conduit Moderate—jet width between 20% and 40% of the annular width of the valve/conduit Severe—jet width > 40% of the valve/conduit annular width B.

Based on diastolic flow reversal Trace—Diastolic color flow reversal limited to the beginning at valve/conduit Mild—Diastolic color flow reversal limited to the proximal half of the main pulmonary artery Moderate—Diastolic color flow reversal extending into distal half of the main pulmonary artery Severe—Diastolic flow reversal extending into proximal branch pulmonary arteries

Source: Adapted from Brown DW et al. J Am Soc Echocardiogr 2012;25:383–92.

It also plays an adjunctive role in risk stratification of patients who are more likely to have sudden cardiac death by determining the impact of hemodynamic burden of pulmonary regurgitation and right ventricular impairment on the electrophysiological substrates. In patients undergoing cardiopulmonary exercise testing, a decline in functional aerobic capacity (maximum VO2) to <70% of gender–age-predicted maximum value or a decline over 20% compared with serial testing is considered significant. Adults with right ventricle to pulmonary artery (RV to PA) conduit should undergo evaluation for abnormal ventricular function and conduit obstruction at peak exercise. Besides tetralogy of Fallot, others with RV to PA conduit include patients with pulmonary atresia and multiple aortopulmonary collaterals, truncus arteriosus, or d-transposition of great arteries. A RV-to-PA conduit is considered to be stenotic when the mean continuous wave Doppler gradient across the conduit is over 20 mm Hg on echocardiography. Hasan et al. reported a protocol with mean instantaneous systolic gradient and maximum instantaneous systolic gradient across the RV-to-PA conduit obtained at rest and immediately postexercise, using continuous wave Doppler through the conduit in the parasternal short-axis view.154

Cardiac Catheterization Angiography plays a limited role in the current era for the postoperative adult with tetralogy of Fallot. It is not a reliable test for assessment of pulmonary regurgitation, since the angiographic severity may be influenced by catheter position across the pulmonary artery. It accurately

assesses coronary artery disease, pulmonary artery or branch stenosis, and pulmonary vascular resistance in adults with pulmonary hypertension due to longstanding shunts. It is routinely performed in conjunction with potential catheter-based interventions such as percutaneous pulmonary valve implantation. The Melody transcatheter pulmonary valve (Medtronic, Inc., Minneapolis, MN) is approved by the US Food and Drug Administration for treatment of patients with regurgitant or stenosed right ventricular outflow tract (RVOT) conduits. The indications for implantation can vary from isolated pulmonary regurgitation to relief of RVOT obstruction, from a bridging procedure to a more definitive therapy.155 Echocardiography complements MRI in determining the suitability for percutaneous pulmonary valve implantation by assessing the following parameters: (a) right ventricular outflow tract diameter between 16 and 24 mm, (b) right ventricular outflow gradient of >30 mm Hg, (c) the presence of discrete waist or calcification for implantation, and (d) the absence of significant pulsatility. MRI provides additional information about any limitations in access to the right ventricle due to occlusion of the central vein. Echocardiography also identifies procedural complications resulting from implantation of the percutaneous pulmonary valve, including rupture of the RVOT conduit, embolization or migration of the device, and perforation of a heart chamber that may manifest as a pericardial effusion. Other short- and long-term complications include stent fracture resulting in recurrent obstruction, endocarditis, valvular stenosis/regurgitation, paravalvular leak, and valvular thrombosis. The most common complication


noted during follow-up of the Melody valves are stent fractures with an incidence of approximately 20%.156 Other interventional procedures include ASD closures, angioplasty/stent implantation of obstructed pulmonary arteries/branches, and deployment of coils in the collateral vessels or systemic–pulmonary artery shunts.

Magnetic Resonance Imaging/Computed Tomography MRI is the current reference standard for quantification of right ventricular volume and the systolic function.157,158 It provides accurate measurements of the aorta, pulmonary artery, and its branches. Areas of myocardial fibrosis due to previous surgeries can be identified by gadoliniumenhanced MRI. For preoperative evaluation in adults who are unable to have an MRI (due to devices such as pacemakers/ defibrillators), CTA is an alternative. In addition, it allows us to identify anomalous coronaries and calcium score.

Surgery in a Postoperative Adult with Tetralogy of Fallot The ACC/AHA Class I indication for surgery in a postoperative adult with tetralogy of Fallot is:3 • Pulmonary valve replacement for symptomatic severe pulmonary regurgitation with declining exercise tolerance Since bioprosthetic valves have a limited life expectancy, surgery should be performed only when it is clearly indicated. The porcine bioprosthetic valves have shown better durability than the cryopreserved homografts. Many studies have proposed additional criteria in symptomatic adults presenting with exertional dyspnea, heart failure, and ventricular arrhythmias. These include progressive right ventricular dilatation. When the pulmonary valve replacement is performed in a timely fashion, it may lead to improvement in symptoms, reduction in right ventricular size, and recovery of systolic function. The timing of surgery in asymptomatic adults with pulmonary regurgitation remains controversial. It may be considered when there is an objective evidence of a decline in exercise capacity on stress testing and progressive right ventricular enlargement confirmed on MRI. Based on the data from two studies, in order to expect improvement in right ventricular function following pulmonary valve replacement, the surgery should be considered when the right ventricular end-diastolic volume is between 150 and

1835

170 cc/m2; and/or when the right ventricular end-systolic volume reaches 85 cc/m2.159,160 Other criteria include widened QRS over 180 milliseconds or an annual increase in QRS width over 3.5 milliseconds in the setting of ventricular arrhythmias and worsening tricuspid regurgitation. Concomitant surgical removal of the right ventriculotomy scar, right ventricular outflow tract aneurysm, pulmonary arterioplasty, aortic root, aortic valve repair/ replacement, and closure of residual shunts are performed to improve the hemodynamic status. Surgical relief of RVOT obstruction should be considered when RVSP is over two thirds of the systemic pressure. Intraoperative transesophageal echocardiography plays an important role, ensuring the adequacy of repair in these patients.

The Postoperative Adult Although patients may demonstrate some symptomatic improvement with medical therapy, pulmonary valve replacement is the only treatment modality with proven long-term benefit. Serial echocardiograms may show a reduction in right ventricular size, an improvement or at least stabilization of right ventricular function. In later years, following bioprosthetic pulmonary valve replacement or placement of an extracardiac conduit (from the right ventricle to pulmonary artery), stenosis or regurgitation may develop and require further reoperations to maintain functional improvement.161 An overall review of multiple studies shows that pulmonary valve replacement in tetralogy of Fallot postintracardiac repair shows an improvement in clinical outcomes. Symptoms resolve and right ventricular function often improves. Several retrospective reviews have reported reduction in right ventricular end-diastolic and systolic volumes along with an increased right ventricular stroke volume.162 Meijboom et al. reported that surgery for pulmonary valve replacement should be offered to symptomatic patients for best outcomes in the majority of adults, who have undergone intracardiac repair in childhood and present with severe pulmonary regurgitation and right ventricular dilatation.163

D-Transposition of the Great Arteries In d-transposition of the great arteries (d-TGA), there is ventriculoarterial discordance with abnormal origins of

1836


the aorta and pulmonary artery. This implies that the aorta arises from the systemic morphological right ventricle and lies rightward and anterior to the pulmonary artery, which in turn arises from the pulmonic morphological left ventricle. Common associated defects include a shunt lesion, a VSD (45%), an ASD, or a PDA that allows intermixing of the deoxygenated and oxygenated blood to permit survival, since this circulation is a parallel circuit and will not be compatible with life without any communication. Most individuals are diagnosed early in life with this form of cyanotic congenital heart disease and have undergone one of the types of repairs. Other associated defects include left ventricular outflow tract (LVOT) obstruction, coarctation of the aorta, and anomalies of the coronary ostia due to transposition.31

Postatrial Switch Repair Many older adults seen in our practice have had an atrial switch repair. In this type of surgery, the deoxygenated blood from the superior and inferior vena cava is directed via a baffle into the left ventricle, and then pumped into the pulmonary artery. The left ventricle becomes the subpulmonic ventricle. The oxygenated blood returns through another baffle from the pulmonary veins into the right ventricle and gets pumped into the aorta. This makes the morphological right ventricle the subaortic or the systemic ventricle. The two types of atrial switch operations are the Senning and the Mustard repairs. They differ primarily in terms of the material used to create the baffles. In the Senning operation, the baffle is created from the patient’s tissues (right atrial wall and part of the atrial septum).164 The Mustard operation uses pericardium and synthetic material to make the baffle.165 The interatrial baffles can deteriorate over time leading to obstruction or leaks. The scar tissue along atrial incisions and the foreign material may become substrates for atrial arrhythmias. Surgical damage of the sinus node and conduction system makes pacemaker surgery more likely in adulthood.

Echocardiography Serial echocardiography is performed in adults who have undergone atrial switch repair to assess the morphological right ventricular size and function. Most adults have a globular-shaped, hypertrophied morphological right

ventricle, which is functioning as a systemic ventricle by pumping into the aorta. In the parasternal short-axis views, the left ventricle appears compressed due to a D-shaped septum or bowing of the septum toward the morphological left ventricle. The aorta and the pulmonary artery can be seen parallel to each other in the parasternal long-axis view and in the same plane in the parasternal short-axis view (Figs 75.20A and B). The systemic (morphological right) ventricular function is impacted by the degree of systemic AV (tricuspid) valve regurgitation in a way quite similar to the impact of the mitral regurgitation on the left ventricle in normal hearts. Progressive aortic regurgitation increases the workload on the systemic (morphological right) ventricular function. Subpulmonic stenosis increases pressure load on the left ventricle. Patients with baffle obstructions or leaks may present with dyspnea or worsening atrial arrhythmias. Flow acceleration, turbulent flow on color Doppler, and increased Doppler gradients indicate baffle narrowing or obstruction. Baffle issues are more commonly seen following a Mustard rather than a Senning repair and usually involve the superior limb.166 Bottega et al. reported obstruction of the superior limb in 44% of the adults postMustard repair.167 The velocities in the superior limb of the systemic venous baffle can be measured from a parasternal or tilted apical four-chamber view. Baffle obstruction by Doppler echocardiography is considered when there is a pulsed wave Doppler peak velocity of ≥ 1.5 m/s with a

A

B

Figs 75.20A and B: Diagrammatic representation of the transthoracic echocardiogram in d-transposition of the great arteries (DTGA). The aorta and the pulmonary artery (PA) are seen in parallel to each other in the parasternal long-axis view (A) and in the same plane (rather than criss-cross) in the parasternal short-axis view (B). (LA: Left atrium; LV: Left ventricle; RV: Right ventricle).


characteristic loss of the biphasic Doppler profile.167,168 Pulmonary venous baffles are easier to image by echocardiography and should be suspected when there is an increase in the left ventricular systolic pressure.169 Baffle leaks usually result in right heart enlargement as seen with long-standing atrial septal defects. In these adults, the subpulmonary left ventricle can appear more D-shaped with a compressed appearance when there is a hemodynamically relevant baffle leak, subpulmonary obstruction, or pulmonary hypertension.169 Color Doppler may reveal the site of the shunt and an agitated saline contrast study may confirm it. TEE may be required when there is limited visualization by a transthoracic echocardiogram. TEE also allows direct examination of caval anastomosis.170 Hepatic venous flow

1837

and superior vena caval patterns showing presystolic flow reversal with atrial contraction indirectly indicate patency of the caval anatomosis. Residual ventricular septal defects or patch leaks should be examined with color Doppler. A synopsis of echocardiographic assessment of the postoperative adult with d-TGA is reviewed in Table 75.16. Three-dimensional echocardiography may add incremental value to visualization of the baffle and tricuspid valve anatomy in the post-Mustards adults. It may provide a more comprehensive assessment of baffle obstruction by allowing it to be viewed in multiple planes and projections.171 In addition to the en face viewing of the intra-atrial baffle and measurements of vena contracta from the baffle leaks, it provides complementary

Table 75.16: D-Transposition of the Great Arteries


Shunt lesions—ventricular septal defect (usually perimembranous), atrial septal defect and patent ductus arteriosus

•

Left ventricular outflow tract (LVOT) obstruction—pulmonary stenosis, usually valvular but may be subvalvular

•

Coarctation of the aorta

•

Coronary artery anomalies

•

Right ventricular outflow tract (RVOT) obstruction (subaortic narrowing)

Echocardiographic assessment Most of the adults have had surgeries in their childhood •

Great arteries—aorta and pulmonary artery—are seen parallel to each other in the parasternal long-axis view.

•

In the short-axis view they are seen next to each other with the aorta being anterior and rightward.

Postoperative Atrial switch repair •

Assessment right (systemic) ventricular size systemic function

•

Right ventricular hypertrophy

•

Baffle leak

•

Baffle obstruction

•

Estimation of right ventricular systolic pressure/degree of pulmonary hypertension

Arterial switch repair •

Assessment of left ventricular size and systolic function

•

Coronary artery fibrosis may lead to ischemia/infarction—stress echocardiography is performed to assess wall motion abnormalities

•

Neoaortic valve regurgitation

•

Mild aortic root dilatation

•

Pulmonary artery stenosis at the valvar supravalvar or peripheral level

•

Estimation of right ventricular systolic pressure/degree of pulmonary hypertension

Post-Rastelli repair •

Assessment of biventricular ventricular size and systolic function

•

Conduit obstruction

1838


anatomical details of the pulmonary valve and the left ventricular outflow tract.172

Stress Echocardiography Exercise capacity may be limited postatrial switch repair due to stiffness and noncompliance of the baffles, deterioration in systemic ventricular function, sick sinus syndrome, or advanced conduction disease. Baffle problems appear to have the most effect on exercise ability because of impaired ventricular filling and limited ability to augment stroke volume during exercise.173 Hence, functional capacity assessed objectively by exercise stress echocardiography should be followed by a search for causes of hemodynamic impairment such as baffle obstruction, progressive tricuspid regurgitation, subpulmonic obstruction, impaired systemic ventricular function, or chronotropic incompetence. Routine repetition of exercise studies every 3 years is recommended even in the absence of symptoms, since gradual declines in function often go unnoticed by patients.169

Cardiac Catheterization Systemic or pulmonary venous baffle obstructions are diagnosed by angiography and can be often be relieved by balloon-expanded stent implantation. Some of the baffle leaks can be eliminated by implanting smaller devices. Intracardiac echocardiography plays a role in guiding percutaneous closure of atrial baffle defects.175

Magnetic Resonance Imaging/Computed Tomography Baffle stenosis or leak may be more clearly defined by MRI/ CTA.167 Baffle patency should be evaluated by either of these modalities before transvenous device implantation. MRI is also the gold standard for accurate assessment of systemic right ventricular volumes and function, since most echocardiographic parameters have reduced sensitivity and marked intraobserver variability.174

Reoperation for D-Transposition of the Great Arteries Postatrial Switch Repair The Class I ACC/AHA indications for surgery in d-TGA postatrial switch repair (Mustard or Senning) are the following:3 • Moderate to severe systemic (morphological tricuspid) AV valve regurgitation without significant ventricular

• • •

dysfunction. Baffle leak with left-to-right shunt > 1.5:1, right-to-left shunt with arterial desaturation at rest or with exercise, symptoms, and progressive ventricular enlargement that is not amenable to device intervention Superior vena cava or inferior vena cava obstruction not amenable to percutaneous treatment Pulmonary venous pathway obstruction not amenable to percutaneous intervention Symptomatic severe subpulmonary stenosis.

Postarterial Switch Repair Dr A Jatene first described the arterial switch repair in which the great arteries are translocated to achieve their anatomically correct positions and the coronary arteries are reimplanted into the neoaorta.176 The most common long-term issues postarterial switch repair in a young adult with d-TGA are neoaortic root dilatation and neoaortic valve regurgitation, since the current aortic valve, which was originally a pulmonary valve, is now placed in a high pressure circulation. Supravalvular pulmonary stenosis often occurs at the arterial anastomotic sites. Due to reimplantation of the coronary arteries into the neoaorta, fibrosis and scarring at the anastomotic sites of the coronaries may cause ischemia in young adults. Coronary angiography or CTA is indicated when ischemia is likely. Adults with intramural or single coronary arteries have a higher mortality than those with a typical coronary pattern. Among the long-term issues are supravalvular stenosis and aortic aneurysm.

Echocardiography Neoaortic dilatation and aortic regurgitation may develop over time. Neoaortic constriction can occur at the site of anastomosis. Patients with previous pulmonary artery banding (although it is now rarely performed) are more likely to have neoaortic root dilatation but it may not necessarily progress on late follow-up. Risk factors for aortic regurgitation include older age at the time of presentation, presence of a VSD, and previous pulmonary artery banding.177

Stress Echocardiography Following atrial switch repair, stress echocardiography is performed to screen for exercise-induced ischemia.


Cardiac Catheterization Coronary ostial fibrosis leading to coronary ischemia prompts early catheterization in those adults who have undergone reimplantation of the coronaries into the base of the neoaorta.

Magnetic Resonance Imaging/Computed Tomography These imaging modalities are helpful in assessment of the neoaortic diameters, coronary artery ostial fibrosis (that can lead to myocardial ischemia), and extracardiac structures such as pulmonary artery stenosis.

Reoperation for D-Transposition of the Great Arteries Postarterial Switch Repair The Class I indications for surgery in d-TGA postarterial switch repair include: • Symptomatic severe right ventricular outflow tract obstruction (conduit obstruction) not amenable to catheter-based intervention with a peak-to-peak gradient > 50 mm Hg, or with concomitant severe pulmonary regurgitation • Symptomatic myocardial ischemia that cannot be relieved by catheter-based intervention in an adult with a coronary artery abnormality • Severe symptomatic neoaortic valve regurgitation • Severe neoaortic root dilatation ≥ 55 mm.

Post-Rastelli Repair The Rastelli procedure is performed in d-TGA that is associated with a large VSD and significant pulmonary stenosis. In this surgical repair, a right ventricle to pulmonary artery conduit allows blood flow from the right ventricle to reach the branch pulmonary arteries, usually in patients with right ventricular outflow tract obstruction.178

Echocardiography Echocardiography plays an important role in evaluation of long-term complications including right ventricular outflow tract (RVOT) obstruction, pulmonary conduit obstruction with degeneration and calcification of the pulmonary valve, residual shunts, and degree of pulmonary and tricuspid regurgitation. The tricuspid regurgitant jet velocity helps in estimation of the right ventricular systolic

1839

pressure, which is usually elevated in the setting of conduit obstruction. Progressive tricuspid regurgitation with right ventricular enlargement, hypertrophy, and failure are bad prognostic signs indicating high risk of mortality. Left ventricular outflow tract (LVOT) obstruction can occur at any level in the long intraventricular baffle through the VSD to aorta. Structural abnormalities of the great arterial walls make these adults prone to aortic root dilatation and aortic valve regurgitation.

Cardiac Catheterization Cardiac catheterization determines the conduit gradient accurately. Catheter-based interventions such as intraconduit percutaneous pulmonary valve implantation, and dilation with or without stent implantation for relief of branch pulmonary artery stenosis can be performed when indicated.

Magnetic Resonance Imaging/Computed Tomography Prior to surgery, MRI/CTA may be helpful in assessment of adults with significant conduit obstruction/leaks or branch pulmonary stenosis.

Reoperation for D-Transposition of the Great Arteries Post-Rastelli Repair The ACC/AHA Class I indications for reoperation after Rastelli procedure in the following settings are:3 Prior Conduit and/or Valve Replacement • Symptomatic adult with conduit obstruction with a peak-to-peak gradient > 50 mm Hg • Subaortic (baffle) obstruction with a mean gradient > 50 mm Hg and left ventricular hypertrophy • Severe symptomatic aortic regurgitation requiring concomitant surgery. Conduit Regurgitation • Symptomatic/decreased exercise tolerance • Severe right ventricular enlargement with severely reduced right ventricular function • Severe tricuspid regurgitation. Residual Ventricular Septal Defect • Increased left ventricular size from volume overload • Reduced right ventricular function from pressure overload • Systolic pulmonary artery pressure > 50 mm Hg

1840 • •


Right ventricular outflow tract obstruction with peak instantaneous gradient > 50 mm Hg Pulmonary artery pressure less than two thirds of systemic pressure and responsive to pulmonary vasodilators.

The Postoperative Adult In addition to the residua and sequelae specific to the type of surgery (atrial or arterial switch or Rastelli repairs) as detailed above, the postoperative adult with d-TGA may require the following surgeries: Pacemaker Surgery with Epicardial Leads • In adults with significant residual intracardiac shunts or systemic venous obstruction, epicardial leads are the safest option. Pulmonary Artery Stenosis or Branch Pulmonary Stenosis • Surgery is performed when interventional procedures are not feasible in adults with severe pulmonary artery stenosis or branch pulmonary stenosis.

Congenitally Corrected Transposition of the Great Arteries (CCTGA) Although far less common than d-TGA, congenitally corrected transposition of the great arteries (CCTGA) can sometimes go undiagnosed into adulthood, especially in the absence of any associated defects. Adults with unoperated CCTGA are often misdiagnosed in adulthood and referred late to ACHD specialists for appropriate management, despite having symptomatic systemic AV valve regurgitation and impaired morphological right ventricular (systemic) function.179 In addition to the ventriculoarterial discordance (the great arteries–aorta and pulmonary arising from opposite ventricles), there is atrioventricular discordance (the right atrium drains into left ventricle through the mitral valve, left atrium drains into right ventricle through the tricuspid valve) due to ventricular inversion. The term “corrected” refers to the physiologically normal direction of blood flow due to “double discordance,” with “two wrongs try to make a right” resulting in the morphological right ventricle pumping into the aorta and the morphological left ventricle into the pulmonary artery. It has been sometimes referred to as “l-transposition,” because the morphological right ventricle is to the left of the morphological left ventricle. Levocardia with the apex of the heart in the left side of the chest is most common, but some cases may have

mesocardia (apex in midline) or dextrocardia (apex in the right side of the chest). The diagnosis of CCTGA should be highly considered in adults with dextrocardia. Heart failure is common by the fourth and fifth decades and has been reported in 51% of adults with associated defects versus in 34% without any associated defects.180 The systemic right ventricular function is usually impaired due to long-standing tricuspid (systemic AV valve) regurgitation and influences the timing of surgery in CCTGA with or without associated lesions.181 The most common associated defect is an abnormality of the systemic AV valve that may occur in up to 90% of the cases (Ebstein-like, dysplastic).182,183 Other associated defects include a perimembranous VSD in approximately 70% and subvalvular pulmonary stenosis in approximately 40%. In a multi-institutional study, Graham et al. reported aortic regurgitation in 25% to 36% of adults with CCTGA.180 The presence of a VSD and significant pulmonary stenosis may contribute to cyanosis. A higher incidence of endocarditis (11%) has been reported in these adults.184 Most adults are likely to get a pacemaker implantation, since conduction abnormalities are so common in this population with complete heart block occurring at the rate of 2% per year.185

Echocardiography Unfortunately, this diagnosis may be missed on echocardiography because of failure to identify the abnormal position of the AV valves associated with ventricular inversion. In addition, the 1% of adults with CCTGA without associated defects are even more likely to go undiagnosed into adulthood. Identifying the relationship of the great arteries and defining the position of the morphological tricuspid valve are essential for clinching the diagnosis on echocardiography. As seen in d-TGA, the two great arteries are parallel to each other in the modified parasternal long-axis view. They are seen in the same cross-sectional plane in the parasternal short-axis views. The position of aorta is anterior, leftward, and superior, while the pulmonary artery is rightward, posterior, and inferior. Identification of the ventricular morphology and positions of the AV valve that are best seen in the apical four-chamber view remains critical in making the diagnosis (Fig. 75.18). The AV valves always follow their ventricles and, therefore, the tricuspid valve (referred to as the systemic AV valve) is on the left side with the morphological right (systemic) ventricle posing as the left AV valve, while the mitral valve (referred to as the pulmonic


1841

Fig. 75.21: Transthoracic echocardiogram in congenitally corrected transposition of the great arteries (CCTGA) showing ventricular inversion and tricuspid valve on the left side (apically placed in relation to the mitral valve). (LA: Left atrium; LV: Left ventricle; MB: Moderator band; MV: Mitral valve; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve). Source: With permission from Vijayalakshmi IB, Rao PS, Chugh R, editors. A Comprehensive Approach to Congenital Heart Diseases. 1st ed. New Delhi: Jaypee Brothers Medical; 2013: 767.

Fig. 75.22: Transthoracic echocardiogram in congenitally corrected transposition of the great arteries (CCTGAs) showing that the left ventricle pumps into the transposed pulmonary artery and its branches (arrows) in a modified four-chamber view. (LV: Left ventricle; RV: Right ventricle).

AV valve) is on the right side with the morphological left (pulmonic) ventricle (Fig. 75.21). The systemic right ventricle pumps into the aorta that is identified by its candy cane appearance. The left ventricle pumps into the pulmonary artery, which is identified by its right and left branches in a modified apical four-chamber view (Fig. 75.22). The complex shape of the morphological right ventricle makes quantification of systemic ventricular function by echocardiography more challenging. Echocardiographic assessment of the systemic ventricular function and degree of systemic AV valve (morphological tricuspid) regurgitation are extremely important since long-term outcomes including heart failure and mortality are impacted by the inter-relationship between the severity of regurgitation and the declining systemic ventricular function. The morphology of the systemic AV valve (morphological tricuspid), the dilatation of its annulus (due to enlarging systemic ventricle), and the presence of pacemaker wire may all contribute to failure of leaflet coaptation and further progression of regurgitation. Long-standing tricuspid regurgitation is a major risk factor for deterioration of right ventricular function.181

the systemic ventricular contractile reserve can be made by stress echocardiography that also allows assessment of chronotropic insufficiency.

Exercise Testing with Stress Echocardiography While treadmill stress testing provides an objective assessment of functional capacity, a good estimation of

Magnetic Resonance Imaging The best method for quantification of systemic ventricular function is an MRI, which is currently the reference standard. Since many adults with CCTGA have devices (pacemakers or defibrillators), CTA is the next best option when MRI cannot be performed.

Cardiac Catheterization The role of cardiac catheterization is mainly for delineating the coronary anomalies or atherosclerosis prior to surgery. It also allows evaluation of pulmonary vascular reactivity in adults with significant pulmonary hypertension.

Surgery for CCTGA Referral to cardiac surgery should be sought for early systemic AV valve replacement in symptomatic adults or before the systemic ventricular ejection fraction declines below 45%.186 It is more likely to occur in adults with tricuspid valve abnormalities with progressive tricuspid regurgitation. Other echocardiographic signs that should alert the clinician are an enlarging right ventricle, left atrial

1842


enlargement, progressive pulmonary hypertension, and the appearance of atrial arrhythmias. The key ACC/AHA Class I indications for surgery in adults with CCTGA are the following:3 • Unrepaired CCTGA or post-tricuspid valve repair with severe AV valve regurgitation • Left ventricle is functioning at systemic pressures postbiventricular repair • Progressive moderate to severe aortic regurgitation leading to ventricular dilatation and impaired function • Conduit obstruction with – Markedly high right ventricular pressures and/or impaired morphological right ventricular function after anatomical repair – Markedly elevated left ventricular pressures in an adult with a nonanatomical correction.

of the tricuspid valve. Following surgery, the prosthetic systemic AV valve (that replaced the tricuspid valve) should be monitored by echocardiography along with periodic assessment of systemic ventricular function, pulmonary conduit function (post-Rastelli repair), degree of aortic regurgitation, progression of pulmonary hypertension, and evaluation of residual septal defects. After pacemaker implantation, pacing has been shown to cause a septal shift that may aggravate dilatation of the systemic ventricle and precipitate worsening of systemic AV valve regurgitation. Hence, these should be watched more closely after pacemaker implantation. A synopsis of echocardiographic assessment of CCTGA is reviewed in Table 75.17.

The Postoperative Adult

Truncus arteriosus is also known as truncus arteriosus communis and common aorticopulmonary trunk. Approximately 80% of the infants survive at 1 year without surgical intervention.187,188 Since mortality without surgery

Tricuspid valve repair is less likely to be a long-term solution in many adults due to abnormal morphology

Truncus Arteriosus

Table 75.17: Congenitally Corrected Transposition of the Great Arteries


Ventricular septal defect—perimembranous (60–80%)

•

Pulmonary, subpulmonary or supravalvular stenosis

•

Tricuspid (left AV valve) anomaly—Ebstein’s anomaly, Ebstein-like or dysplastic morphological tricuspid valve

•

Tricuspid (left AV valve) regurgitation

•


•


•

Aortic or subaortic stenosis

•


•

Coarctation of aorta

•

Conduction abnormalities—complete heart block

•

Dextrocardia

•

Coronary artery anomalies (inverted coronaries due to ventricular inversion)


Systemic ventricular (morphological right ventricle) size and function

•

Degree of systemic AV (tricuspid) valve regurgitation

•

Identification of associated defects

Postoperative •

Systemic ventricular (morphological right ventricle) size and function

•

Degree of systemic AV (tricuspid) valve regurgitation

•

Rule out residual shunt lesions

•

Conduit stenosis (in Rastelli repair)

•


•

Thromboembolic risk


is very high in infancy, most adult survivors have had previous repairs. This defect is characterized by a single great artery with a single semilunar valve. The single great arterial vessel arises from the base of the heart giving rise to the coronary, pulmonary, and systemic arteries. It is larger than the aorta with poorly developed sinuses of Valsalva, and has a single semilunar valve that is also known as the “truncal valve.” A large nonrestrictive, subarterial VSD is required for intermixing of blood between the two ventricles. While the VSD is usually described as membranous, it has also been thought to result from absence of the distal pulmonary infundibulum (both septal and free wall).189 Since the VSD is roofed by the truncal valve, there is poor truncal support, and truncal valve regurgitation occurs.31 The truncal valve may be trileaflet in the majority (nearly 70%), quadricuspid in around 20% to 25%, and bicuspid in around 7% to 9%.189 When the truncal valve is quadricuspid, it is a combination of the three leaflets of the aortic valve and pulmonary leaflet tissue.189 The pulmonary arteries arise from the posterolateral aspect of the common arterial trunk with separate origins for the right and left branches. A right aortic arch is present in 20% to 30% of the cases.31,189

Table 75.18: Truncus Arteriosus


Right aortic arch—30%

•

Interrupted aortic arch

•

Abnormal truncal valve – Trileaflet (most common) – Quadricuspid – Bicuspid

•

Truncal valve stenosis/regurgitation

•

Left superior vena cava

•

Secundum atrial septal defect

•

Absence of branches of the pulmonary artery

•

Anomalous origin of the coronary artery

Echocardiographic assessment—postoperative •

Biventricular size and function

•

Aortic root size

•

Aortic (truncal) valve regurgitation

•

Rule out residual shunts

•

Assessment of any associated defects

•

Conduit patency or regurgitation

1843

The origins and epicardial course of the coronaries are variable and often anomalous. The left coronary usually arises from the left posterior aspect of the truncus while the right coronary often arises from the right anterior aspect of the truncus.31

Echocardiography On transthoracic echocardiography, the parasternal longaxis view shows the truncal root, valve, and sometimes the origins of the pulmonary arteries. The apical four-chamber view is helpful in demonstrating a VSD and an overriding truncus. The suprasternal views allow identification of a right aortic arch and coarctation of the aorta. Color Doppler is useful in identifying truncal valve stenosis or regurgitation, presence of pulmonary stenosis at the origin of the branches, and for determining the direction of the shunt. An agitated saline contrast study is performed to rule out right-to-left shunts and to define the right ventricular outflow tract in the parasternal short-axis views or the subcostal views.190,191 Associated defects are coarctation of aorta, interrupted aortic arch, right aortic arch, patent ductus arteriosus, ASD, and tricuspid stenosis. In the absence of significant pulmonary stenosis, pulmonary hypertension develops. A synopsis of echocardiographic assessment of truncus arteriosus is reviewed in Table 75.18.

1844


Magnetic Resonance Imaging/Computed Tomography Since extracardiac malformations occur in up to 40% of these individuals, MRI or CTA are very useful for assessment of aortic arch anomalies and branches pulmonary stenosis.

Cardiac Catheterization Besides evaluation of the coronaries, cardiac catheterization is performed in conjunction with stent placement when there is conduit obstruction.

Surgery for Truncus Arteriosus Surgery is indicated for conduit failure not amenable to intervention, severe truncal regurgitation, and enlarging truncal dimensions.

The Postoperative Adult Improvements in early diagnosis and primary neonatal repair have allowed better survival.192 Palliation with pulmonary artery banding (which delays primary surgery to a later age) is no longer believed to offer any benefit and is associated with high mortality rates. McGoon, Rastelli, and Ongley performed the first successful surgical repair of truncus arteriosus in 1967 using an aortic homograft with an aortic valve to establish continuity from the right ventricle to the pulmonary artery.193 The surgical approach has been modified over the past four decades. In these operations, reconstruction of the right ventricular outflow tract is necessary to establish a separate pulmonary circulation. However, there continues to be a need for reoperations. In a recent study, the actuarial survival at 30 years was reported as approximately 83% with a reoperation rate of 76% among survivors, and truncal valve replacement was required in 20% during long-term follow-up.194 Most adults seen in our practice have undergone a homograft or xenograft repair. Homografts are preferred because of lower rates of stenosis and longer durability with long-term freedom from reoperations. Smaller conduit size at the time of the initial surgery also leads to early reoperation because the child outgrows it during developing years. Other reasons for graft failure are conduit calcification, stenosis, and infective endocarditis. Catheter-based interventions for conduit valve obstruction may reduce some of the reoperations by allowing the

conduits to function for a longer duration. Another major indication for reoperation that impacts longterm outcomes/mortality is truncal valve regurgitation requiring replacement or repair.195–197 The long-term residua and sequelae assessed by echocardiography are progressive homograft or conduit obstruction/regurgitation, truncal or prosthetic valve regurgitation/stenosis, residual VSD, impaired biventricular function, truncal root dilatation, and pulmonary hypertension. These adults may have limitations in functional capacity, and are at risk of developing heart failure, cardiac arrhythmias, and infective endocarditis.

Double Outlet Right Ventricle A key feature in this heterogenous group of defects described as the double outlet right ventricle (DORV) is that the aorta and the pulmonary artery arise primarily (>50%) from the right ventricle.198 Dr Joseph Perloff eloquently states, “It has been argued that the malformation is virtually unclassifiable because of its excessively complex and diverse anatomy.”31 The clinical patterns in this spectrum of defects vary based on the size/location of the VSD, presence or absence pulmonary stenosis, ventricular size, status of the atrioventricular valves (AV), and the degree of pulmonary vascular resistance. Dr Perloff describes the two most common clinical types: (a) subaortic VSD without pulmonary stenosis and (b) subpulmonary VSD without pulmonary stenosis, with each one having either low or high pulmonary vascular resistance.31

Echocardiography Most individuals with DORV are operated in childhood. Echocardiography in an unoperated adult focuses on the relation of the aorta and pulmonary artery, the position and relation of the VSD, any obstruction (subpulmonic or subaortic), presence of pulmonary hypertension, and identification of a constellation of associated defects. Irreversible pulmonary vascular disease with Eisenmenger physiology will preclude surgical repair in adulthood, as seen in adults with large subaortic or subpulmonic VSDs without pulmonary stenosis.199 The best views are the parasternal and subcostal views for identification of the origin of both great arteries from the morphological right ventricle.


Surgery for Double Outlet Right Ventricle Depending upon the type, morphology, and circulation, in most cases a Rastelli repair is performed. A conduit from right ventricle (RV) to pulmonary artery (PA), and another conduit from left ventricle to aorta restores the physiological circulation. Other types of repairs are palliative single ventricle (Fontan) surgery, arterial switch type repair (in subpulmonary VSD with transpositionlike physiology), or intracardiac repair as in tetralogy of Fallot (for subaortic VSD with pulmonary/subpulmonary stenosis). Concomitant surgical procedures are performed for associated defects.200,201

The Postoperative Adult The postoperative adult with a Rastelli repair has an external conduit directing blood from the right ventricle into the pulmonary artery and an internal connection between the left ventricle and aorta through the VSD. Follow-up echocardiograms are performed to rule out residual VSD, assess degree of AV valve regurgitation, conduit obstruction (right ventricle to pulmonary artery valve conduit), kinking of the left ventricle to aorta conduit, and status of associated defects (such as COA). The indications for conduit replacement post-Rastelli repair are discussed previously in the section on d-TGA.

Stress Echocardiography Stress echocardiography with treadmill stress testing is valuable in assessing exercise intolerance related to residual hemodynamically significant lesions, exerciseinduced arrhythmias, and chronotropic incompetency.

Cardiac Catheterization In limited cases, cardiac catheterization is performed to assess the pulmonary vascular resistance, and hemodynamic status prior to repair and before transcatheter pulmonary valve implantation in the patients with RV to PA conduits.

Magnetic Resonance Imaging/Computed Tomography MRI/CTA is performed when transthoracic or transesophageal echocardiography are inadequate for assessment of the gradient across the conduits. These imaging modalities allow delineation of the course of the coronaries, aortic root (dilatation/aneurysm), arch (COA), pulmonary

1845

arteries, and the relationship between the chambers, great vessels, and AV valves.202,203

Univentricular Heart The spectrum of univentricular hearts comprises multiple defects that are not amenable to biventricular repair and rely on the dominant ventricle to support both the systemic and pulmonary circulations. CHDs that present with the “single ventricle physiology” are tricuspid atresia, mitral atresia, hypoplastic right or left ventricle, and double inlet left ventricle. The clinical manifestations and prognosis for an adult with any form of a univentricular heart are related to the pulmonary artery blood flow/pressure, which is affected by the presence and degree of pulmonary stenosis, and the level of pulmonary vascular resistance. The majority of the adult survivors have undergone palliative repairs: systemic to pulmonary artery shunt and/or Glenn procedure, or Fontan procedure.

Tricupsid Atresia and the Post-Fontan Adult The most common presentation seen in the adult congenital heart disease clinics is tricuspid atresia (imperforate tricuspid valve) with a large dominant morphological left ventricle and a hypoplastic right ventricle. The great arteries may exhibit ventriculoarterial concordance or discordance (complete transposition of the great arteries). Both arteries may arise from the same chamber or the pulmonary artery may arise from the rudimentary right ventricle. There may be an atrial and/or ventricular septal defect. The majority of these people have undergone Fontan surgery in childhood. The classic Fontan is a right atrial-to-pulmonary artery connection in a patient with tricuspid atresia.204 Over the years, there have been many variations of the Fontan repair (as shown in Figs 75.23A to C) resulting in complete or near-complete separation of the pulmonary and systemic circuits (in those who are not candidates for biventricular repair). In these patients, the pulmonary blood flow requires unobstructed pulmonary arteries, low filling pressure of the single ventricle, normal ventricular function, low pulmonary vascular resistance, and absence of aortic valve regurgitation. Modifications of the surgical techniques have been associated with more favorable outcomes. There are several variables contributing to overall early and late failure of the Fontan. Hypoplastic left heart syndrome with a right-sided tricuspid valve (as the predominant atrioventricular valve) has been shown to increase the early risk more than threefold.205

1846


A

B

C

Figs 75.23A to C: The Fontan procedure and its common modifications. (A) Classic right atrial to pulmonary artery (RA to PA) connection, (B) lateral tunnel Fontan, (C) extra cardiac conduit (ECC) Fontan. (HRV: Hypoplastic right ventricle; IVC: Inferior vena cava; LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; SVC: Superior vena cava).

Echocardiography Echocardiographic assessment of the post-Fontan adult looks into the important determinants that have a longterm effect on the systemic ventricular size and function. The tricuspid atresia is best seen in the apical fourchamber view (Fig. 75.24). These include systemic AV valve morphology, degree of valvular regurgitation, and the presence of subaortic stenosis. The cavoatrial, atrial septal, or ventricular septal defects should be identified, since they contribute to the persistence of cyanosis. In some individuals, fenestrated atrial septum or an adjustable ASD are a necessity. In these cases, the gradient across the fenestration or shunt should

be measured. The best views are the apical four-chamber or the subcostal views. For visualizing the atriopulmonary connection (right atrium to pulmonary artery), one must obtain modified short-axis suprasternal views with right angulation to expose the superior vena cava. Color Doppler and pulsed Doppler interrogation of the flow are necessary to rule out an obstruction. In case of an obstruction, color Doppler will demonstrate flow turbulence, and pulsed wave Doppler will show high velocity flow over 1 m/s with loss of respiratory variation (normal flow is low velocity with respiratory variation giving it a biphasic pattern).206 Spontaneous contrast seen in the Fontan circuit represents slow blood flow in the pathway. Right atrial


Fig. 75.24: Transthoracic echocardiogram showing hypoplastic right ventricle (RV), imperforate tricuspid valve in an adult with tricuspid atresia, as seen in an apical four-chamber view. (ASD: Atrial septal defect; LA: Left atrium; LV: Left ventricle; RA: Right atrium).

thrombus formation is common with a varying incidence depending upon the type of surgical technique and the number of postoperative years. It carries a significant risk of death, especially in the setting of pulmonary embolism that is capable of causing clinical instability. Tsang et al. reported a right atrial thrombus in 12% of adults with the Fontan circulation, and an associated overall mortality rate of 18%.207 The diagnosis is made incidentally in some adults who are asymptomatic. In others, the thrombus may persist despite anticoagulation. There have been various studies addressing antiplatelet therapy versus anticoagulation in this population. Even in patients with extracardiac conduit (ECC) Fontans, antiplatelet therapy alone failed to prevent the rate of early or late thromboembolic events. Their bleeding risk was similar to that when anticoagulation therapy was given alone or in association with antiplatelet drugs.208 Although the debate continues, the current recommendation is that adults with atrial arrhythmias or those with residual ASDs/ fenestrations should be given anticoagulation therapy.

Transesophageal Echocardiography The onset of heart failure symptoms with hepatic congestion and jugular venous distension (in those without a Glenn shunt) or the development of new atrial intractable arrhythmias prompts a search for conduit stenosis. Conduit obstruction may be partially assessable

1847

by transthoracic echocardiography. Therefore, for conduit stenosis (other than in right atrium to right ventricular connection), TEE is the procedure of choice for examining the entire Fontan circuit.209 It allows more detailed examination for potential complications that involve the right atrial portion of the Fontan such as cavoatrial shunting, atrial septal shunting, and atrial to pulmonary artery obstruction. TEE is also indicated to rule out a thrombus in an adult with a thromboembolic event and for assessment of anatomical abnormalities of the Fontan pathway. TEE is more likely to detect atrial and pulmonary thrombi that could not be seen by transthoracic imaging in patients who have undergone the Fontan operation.209,210 Three-dimensional echocardiography may augment the detection or exclusion of thrombi in the Fontan conduit.211 A synopsis of echocardiographic assessment of the post-Fontan adult is reviewed in Table 75.19.

Magnetic Resonance Imaging/Computed Tomography MRI is useful for investigating extracardiac structures such as the patency of the conduits/cavopulmonary pathways, and ventricular and valvular functions.212 MRI and CTA provides information about the systemic and pulmonary arterial/venous anatomy in addition to intracardiac complex defects, ventricular volumes, mass, ejection fraction, and regurgitant fractions.

Cardiac Catheterization The etiology of oxygen-unresponsive hypoxemia in adults with Fontan is determined by cardiac catheterization that can identify potential causes including persistent Fontan fenestration, systemic venous-to-pulmonary venous collaterals, and pulmonary arteriovenous malformations. In heart failure patients, the cause of volume retention may be worsening ventricular function, increasing Fontan circuit pressure, and resistance that exaggerate the rightto-left shunts. Catheter-based closure of residual shunts by coils or ASD devices may relieve the symptoms. Cardiac catheterization plays an important role in assessment of protein-losing enteropathy (PLE) in the postFontan adult. Causes of increased resistance to effective pulmonary flow, such as obstruction to pulmonary flow at the pulmonary artery or venous levels, AV valve stenosis or regurgitation may contribute to progressive PLE. The aortic-pulmonary collaterals can be also be

1848


Table 75.19: Univentricular Heart Post-Fontan Tricuspid Atresia


Univentricular heart/single ventricle physiology with a hypoplastic right ventricle

•


•


•

Transposition of the great arteries

Echocardiographic assessment—postoperative •

Systemic (usually left) ventricular dysfunction

•

Right atrial enlargement

•

Thrombus in the right atrium

•

Atrioventricular (AV) valve regurgitation

•

Conduit obstruction—obstruction of the Fontan connection—usually due to right pulmonary vein compression from an enlarged right atrium or from conduit obstruction.

delineated by aortography. For these adults, creation or enlargement of an atrial septal communication (ASD or fenestration) may decrease the central venous pressure. It is also a prerequisite to pulmonary vasodilator therapy for pulmonary hypertension or heart transplantation evaluation.

CONCLUSIONS Echocardiography plays a vital role in diagnosis and follow-up of adults with congenital heart defects. Every effort should be made to acquire the previous medical records, especially operation notes and imaging studies, in order to understand the blueprint of each individual’s unique anatomy and physiology. It is essential to perform a complete examination and be flexible in performing modified views to acquire the desired images. Equally important is our understanding about the indications for applying the appropriate imaging modalities. Since “our eyes see what the mind knows”, an echocardiographer must have knowledge of the underlying anatomy, types of surgeries, associated defects, long-term residua, and sequelae in order to provide a comprehensive assessment that will direct timely and appropriate treatment.

ACKNOWLEDGMENTS My deepest gratitude to Dr John S Child and Dr Navin C Nanda for their inspiration and the gift of knowledge; to Robert Reber for his expertise as an audiovisual engineer; to Ms Hovey Lee for the extensive literature searches; to the patients and sonographers (Paul Junkel, Terri

McAnallen, Albert Amoranto, and Janae Johnson) at the Echocardiography Laboratory, Kaiser Foundation Hospital, Panorama City, California, for their innumerable clinical contributions and support; and to my dear daughter Tanisha for her unconditional love, patience, and understanding.

REFERENCES 1. Douglas PS, Garcia MJ, Haines DE et al. ACCF/ASE/ AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography. J Am Coll Cardiol. 2011;57(9):1126–66. doi: 10.1016/j.jacc.2010.11.002. J Am Soc Echocardiogr. 2011;24(3):229–67. doi: 10.1016/j. echo.2010.12.008. 2. Ayres NA, Miller-Hance W, Fyfe DA, et al; Pediatric Council of the American Society of the Echocardiography. Indications and guidelines for performance of transesophageal echocardiography in the patient with pediatric acquired or congenital heart disease: report from the task force of the Pediatric Council of the American Society of Echocardiography. J Am Soc Echocardiogr. 2005;18(1):91–8. 3. Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease. J Am Coll Cardiol. 2008;52(23):e143–263. doi: 10.1016/j.jacc.2008.10.001 4. Chang RK, Alejos JC, Atkinson D, et al. Bubble contrast echocardiography in detecting pulmonary arteriovenous shunting in children with univentricular heart after cavopulmonary anastomosis. J Am Coll Cardiol. 1999;33(7):2052–8. 5. Van Hare GF, Silverman NH. Contrast two-dimensional echocardiography in congenital heart disease: techniques, indications and clinical utility. J Am Coll Cardiol. 1989;13(3):673–86.


6. Miller AP, Nanda NC. Contrast echocardiography: new agents. Ultrasound Med Biol. 2004;30(4):425–34. 7. Chugh R. Management of pregnancy in women with palliated and unpalliated congenital heart defects. Curr Treat Options Cardiovasc Med. 2007;9(5):414–27. 8. Savu O, Jurcut R, Giusca S, et al. Morphological and functional adaptation of the maternal heart during pregnancy. Circ Cardiovasc Imaging. 2012;5(3):289–97. 9. Naqvi TZ, Elkayam U. Serial echocardiographic assessment of the human heart in normal pregnancy. Circ Cardiovasc Imaging. 2012;5(3):283–5. 10. Chugh, R, Miner PD, Canobbio MM. Pregnancy, contraception and gynecological issues in women with congenital heart disease In: Vijayalakshmi IB, Rao PS, Chugh R, editors. A Comprehensive Approach to Congenital Heart Diseases. 1st ed. New Delhi: Jaypee Brothers Medical; 2013:783–811. 11. Niwa K, Perloff JK, Bhuta SM, et al. Structural abnormalities of great arterial walls in congenital heart disease: light and electron microscopic analyses. Circulation. 2001;103(3):393–400. 12. Roman MJ, Devereux RB, Kramer-Fox R, O’Loughlin J. Twodimensional echocardiographic aortic root dimensions in normal children and adults. Am J Cardiol. 1989;64(8): 507–12. 13. Devereux RB, de Simone G, Arnett DK, et al. Normal limits in relation to age, body size and gender of two-dimensional echocardiographic aortic root dimensions in persons =15 years of age. Am J Cardiol. 2012;110(8):1189–94. 14. Keane MG, Wiegers SE, Plappert T, et al. Bicuspid aortic valves are associated with aortic dilatation out of proportion to coexistent valvular lesions.Circulation. 2000;102(19 Suppl 3):III35–9. 15. Hiratzka LF, Bakris GL, Beckman JA, et al; American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines; American Association for Thoracic Surgery; American College of Radiology; American Stroke Association; Society of Cardiovascular Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society of Interventional Radiology; Society of Thoracic Surgeons; Society for Vascular Medicine. 2010 ACCF/AHA/AATS/ ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the diagnosis and management of patients with thoracic aortic disease. A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology,American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons,and Society for Vascular Medicine. J Am Coll Cardiol. 2010;55(14):e27–129. 16. Souteyrand G, Motreff P, Lusson JR, et al. Comparison of transthoracic echocardiography using second harmonic imaging, transcranial Doppler and transesophageal echocardiography for the detection of patent foramen ovale in stroke patients. Eur J Echocardiogr. 2006;7(2):147–54.

1849

17. Zito C, Dattilo G, Oreto G, et al. Patent foramen ovale: comparison among diagnostic strategies in cryptogenic stroke and migraine. Echocardiography. 2009;26(5):495– 503. 18. Hagen PT, Scholz DG, Edwards WD. Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy study of 965 normal hearts. Mayo Clin Proc. 1984;59(1):17–20. 19. De Castro S, Cartoni D, Fiorelli M, et al. Morphological and functional characteristics of patent foramen ovale and their embolic implications. Stroke. 2000;31(10):2407–13. 20. Cabanes L, Mas JL, Cohen A, et al. Atrial septal aneurysm and patent foramen ovale as risk factors for cryptogenic stroke in patients less than 55 years of age. A study using transesophageal echocardiography. Stroke. 1993;24(12):1865–73. 21. Shirani J, Zafari AM, Roberts WC. Morphologic features of fossa ovalis membrane aneurysm in the adult and its clinical significance. J Am Coll Cardiol. 1995;26(2):466–71. 22. Mügge A, Daniel WG, Angermann C, et al. Atrial septal aneurysm in adult patients. A multicenter study using transthoracic and transesophageal echocardiography. Circulation. 1995;91(11):2785–92. 23. Mas JL, Arquizan C, Lamy C, et al.; Patent Foramen Ovale and Atrial Septal Aneurysm Study Group. Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both. N Engl J Med. 2001;345(24):1740–6. 24. Vale TA, Newton JD, Orchard E, et al. Prominence of the Eustachian valve in paradoxical embolism. Eur J Echocardiogr. 2011;12(1):33–6. 25. Furlan AJ, Reisman M, Massaro J, et al.; CLOSURE I Investigators. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med. 2012;366(11):991–9. 26. Carroll JD, Saver JL, Thaler DE, et al.; RESPECT Investigators. Closure of patent foramen ovale versus medical therapy after cryptogenic stroke. N Engl J Med. 2013;368(12): 1092–100. 27. Meier B, Kalesan B, Mattle HP, et al.; PC Trial Investigators. Percutaneous closure of patent foramen ovale in cryptogenic embolism. N Engl J Med. 2013;368(12):1083–91. 28. Koenig PR, Abdulla RI, Cao QL, et al. Use of intracardiac echocardiography to guide catheter closure of atrial communications. Echocardiography. 2003;20(8):781–7. 29. Panwar SR, Perrien JL, Nanda NC, et al. Real time/threedimensional transthoracic echocardiographic visualization of the valve of foramen ovale. Echocardiography. 2007;24(10):1105–7. 30. Vigna C, Marchese N, Zanchetta M, et al. Echocardiographic guidance of percutaneous patent foramen ovale closure: head-to-head comparison of transesophageal versus rotational intracardiac echocardiography. Echocardiography. 2012;29(9):1103–10. 31. Perloff JK, Marelli AH. Perloff ’s Clinical Recognition of Congenital Heart Disease. 6th ed. Philadelphia, PA: WB Saunders; 2012.

1850


32. Saric M, Perk G, Purgess JR, et al. Imaging atrial septal defects by real time three-dimensional transesophageal echocardiography: step-by-step approach. J Am Soc Echocardiogr. 2010;23(11):1128–35. 33. Bhaya M, Mutluer FO, Mahan E, et al. Live/Real time three-dimensional transesophageal echocardiography in percutaneous closure of atrial septal defects. Echocardiography. 2013;30(3):345–53. 34. Sinha A, Nanda NC, Misra V, et al. Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale. Echocardiography. 2004;21(8):749–53. 35. Mazic U, Gavora P, Masura J. The role of transesophageal echocardiography in transcatheter closure of secundum atrial septal defects by the Amplatzer septal occluder. Am Heart J. 2001;142(3):482–8. 36. Rigatelli G, Dell’ Avvocata F, Cardaioli P, et al. Five-year follow-up of intracardiac echocardiography-assisted transcatheter closure of complex ostium secundum atrial septal defect. Congenit Heart Dis. 2012;7(2):103–10. 37. Dod HS, Reddy VK, Bhardwaj R, et al. Embolization of atrial septal occluder device into the pulmonary artery: a rare complication and usefulness of live/real time three-dimensional transthoracic echocardiography. Echocardiography. 2009;26(6):739–41. 38. Wei J, Hsiung MC, Tsai SK, et al. Atrial septal occluder device embolization to an iliac artery: a case highlighting the utility of three-dimensional transesophageal echocardiography during percutaneous closure. Echocardiography. 2012;29(9):1128–31. 39. Diab K, Kenny D, Hijazi ZM. Erosions, erosions, and erosions! Device closure of atrial septal defects: how safe is safe? Catheter Cardiovasc Interv. 2012;80(2):168–74. 40. Pinheiro L, Nanda NC, Jain H, et al. Transesophageal echocardiographic imaging of the pulmonary veins. Echocardiography. 1991;8:741–8. 41. Mehta RH, Jain SP, Nanda NC, et al. Isolated partial anomalous pulmonary venous connection: echocardiographic diagnosis and a new color Doppler method to assess shunt volume. Am Heart J. 1991;122(3 Pt 1):870–3. 42. Kronzon I, Tunick PA, Freedberg RS, et al. Transesophageal echocardiography is superior to transthoracic echocardiography in the diagnosis of sinus venosus atrial septal defect. J Am Coll Cardiol. 1990;17:537–42. 43. Pascoe RD, Oh JK, Warnes CA, et al. Diagnosis of sinus venosus atrial septal defect with transesophageal echocardiography. Circulation. 1996;94(5):1049–55. 44. Minette MS, Sahn DJ. Ventricular septal defects. Circulation. 2006;114(20):2190–7. 45. Ammash NM, Warnes CA. Ventricular septal defects in adults. Ann Intern Med. 2001;135(9):812–24. 46. Penny DJ, Vick GW 3rd. Ventricular septal defect. Lancet. 2011;377(9771):1103–12. 47. Espinola-Zavaleta N, Soto ME, Chugh R et al. Ventricular septal defect in adults: analysis of survival with and without interventional procedures. The relevant role of echocardiography. J Clin Exp Cardiolog. 2012;3(5): http:// dx.doi.org/10.4172/2155–9880.1000192

48. Jacobs JP, Burke RP, Quintessenza JA, et al. Congenital Heart Surgery Nomenclature and Database Project: ventricular septal defect. Ann Thorac Surg. 2000;69(4 Suppl):S25–35. 49. Mongeon FP, Burkhart HM, Ammash NM, et al. Indications and outcomes of surgical closure of ventricular septal defect in adults. JACC Cardiovasc Interv. 2010;3(3):290–7. 50. Houston AB, Gnanapragasam JP, Lim MK, et al. Doppler ultrasound and the silent ductus arteriosus. Br Heart J. 1991;65(2):97–9. 51. Gutgesell HP, Huhta JC, Latson LA, et al. Accuracy of two-dimensional echocardiography in the diagnosis of congenital heart disease. Am J Cardiol. 1985;55(5):514–18. 52. Pérez JE, Nordlicht SM, Geltman EM. Patent ductus arteriosus in adults: diagnosis by suprasternal and parasternal pulsed Doppler echocardiography. Am J Cardiol. 1984;53(10):1473–5. 53. Waggoner AD, Barzilai B, Pérez JE. Saline contrast enhancement of tricuspid regurgitant jets detected by Doppler color flow imaging. Am J Cardiol. 1990;65(20): 1368–71. 54. Marek T, Zelizko M, Kautzner J. Images in cardiovascular medicine. Real time 3-dimensional transesophageal echocardiography imaging: adult patent ductus arteriosus before and after transcatheter closure. Circulation. 2009;120(12):e92–3. 55. Sinha A, Nanda NC, Khanna D, et al. Live three-dimensional transthoracic echocardiographic delineation of patent ductus arteriosus. Echocardiography. 2004;21(5):443–8. 56. Chuang YC, Yin WH, Hsiung MC, et al. Successful transcatheter closure of a residual patent ductus arteriosus with complex anatomy after surgical ligation using an Amplatzer ductal occluder guided by live three-dimensional transesophageal echocardiography. Echocardiography. 2011;28(5):E101–3. doi: 10.1111/j.1540-8175.2010.01343.x. Epub 2011 Mar 14. 57. Allwork SP. Anatomical-embryological correlates in atrioventricular septal defect. Br Heart J. 1982;47(5): 419–29. 58. Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006;23(7):598–608. 59. Singh P, Mehta A, Nanda NC. Live/real time threedimensional transthoracic echocardiographic findings in an adult with complete atrioventricular septal defect. Echocardiography. 2010;27(1):87–90. 60. Gonzalez-Juanatey C, Testa A, Vidan J, et al. Persistent left superior vena cava draining into the coronary sinus: report of 10 cases and literature review. Clin Cardiol. 2004;27(9):515–18. 61. Kliger C, Jelnin V, Perk G, et al. Use of multi-modality imaging in a patient with a persistent left superior vena cava, partial anomalous pulmonary venous connection, and sinus venosus-type atrial septal defect. Eur Heart J Cardiovasc Imaging. 2012;13(6):499. 62. Yuce M, Kizilkan N, Kus E, et al. Giant coronary sinus and absent right superior vena cava. VASA. 2011;40(1):65–7.


63. Fathala A. Depiction of ruptured sinus of Valsalva aneurysms by cardiac computed tomography angiography. Exp Clin Cardiol. 2012;17(3):152–4. 64. Terdjman M, Bourdarias JP, Farcot JC, et al. Aneurysms of sinus of Valsalva: two-dimensional echocardiographic diagnosis and recognition of rupture into the right heart cavities. J Am Coll Cardiol. 1984;3(5):1227–35. 65. Mangukia CV. Coronary artery fistula. Ann Thorac Surg. 2012;93(6):2084–92. 66. Velvis H, Schmidt KG, Silverman NH, et al. Diagnosis of coronary artery fistula by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging. J Am Coll Cardiol. 1989;14(4):968–76. 67. Samdarshi TE, Mahan EF 3rd, Nanda NC, et al. Transesophageal echocardiographic assessment of congenital coronary artery to coronary sinus fistulas in adults. Am J Cardiol. 1991;68(2):263–6. 68. Nekkanti R, Mukhtar O, Nanda NC, et al. Transesophageal color Doppler three-dimensional echocardiographic assessment of left circumflex coronary artery fistula. Echocardiography. 2002;19(7 Pt 1):573–5. 69. Mishra J, Puri HP, Hsiung MC, et al. Incremental value of live/real time three-dimensional over two-dimensional transesophageal echocardiography in the evaluation of right coronary artery fistula. Echocardiography. 2011;28(7): 805–8. 70. Liberthson RR, Sagar K, Berkoben JP, et al. Congenital coronary arteriovenous fistula. Report of 13 patients, review of the literature and delineation of management. Circulation. 1979;59(5):849–54. 71. Anderson KR, Zuberbuhler JR, Anderson RH, et al. Morphologic spectrum of Ebstein’s anomaly of the heart: a review. Mayo Clin Proc. 1979;54(3):174–80. 72. Attenhofer Jost CH, Edmister WD, Julsrud PR, et al. Prospective comparison of echocardiography versus cardiac magnetic resonance imaging in patients with Ebstein’s anomaly. Int J Cardiovasc Imaging. 2012;28(5):1147–59. doi: 10.1007/s10554-011-9923-1. Epub 2011 Aug 6. 73. Zuberbuhler JR, Allwork SP, Anderson RH. The spectrum of Ebstein’s anomaly of the tricuspid valve. J Thorac Cardiovasc Surg. 1979;77(2):202–11. 74. Frescura C, Angelini A, Daliento L, et al. Morphological aspects of Ebstein’s anomaly in adults. Thorac Cardiovasc Surg. 2000;48(4):203–8. 75. Oechslin E, Buchholz S, Jenni R. Ebstein’s anomaly in adults: Doppler-echocardiographic evaluation. Thorac Cardiovasc Surg. 2000;48(4):209–13. 76. Shiina A, Seward JB, Edwards WD, et al. Two-dimensional echocardiographic spectrum of Ebstein’s anomaly: detailed anatomic assessment. J Am Coll Cardiol. 1984;3(2 Pt 1):356–70. 77. Olivares-Reyes A, Molina-Bello E, Espinola-Zavaleta N. Congenital quadricuspid pulmonary valve in an adult patient with double valvular lesions and poststenotic dilatation of the trunk and the left branch of the pulmonary artery: a case presentation and review of the literature. Congenit Heart Dis. 2012;7(6):E103–8. 78. Gramiak R, Nanda NC, Shah PM. Echocardiographic detection of the pulmonary valve. Radiology. 1972; 102(1):153–7.

1851

78. Silvilairat S, Cabalka AK, Cetta F, et al. Echocardiographic assessment of isolated pulmonary valve stenosis: which outpatient Doppler gradient has the most clinical validity? J Am Soc Echocardiogr. 2005;18(11): 1137–42. 79. DeGroff C. Response to: “Echocardiographic assessment of isolated pulmonary valve stenosis: which outpatient doppler gradient has the most clinical validity?”. J Am Soc Echocardiogr. 2006;19(3):364. 80. Manzara C, Zampi G, Pergolini A, et al. Real time 3D echocardiography in a young adult with idiopathic dilatation of the pulmonary artery: a case report. Med Ultrason. 2012;14(2):161–3. 81. Bhandari AK, Nanda NC. Pulmonary artery aneurysms: echocardiographic features in 5 patients. Am J Cardiol. 1984;53(10):1438–41. 82. Voet A, Rega F, de Bruaene AV, et al. Long-term outcome after treatment of isolated pulmonary valve stenosis. Int J Cardiol. 2012;156(1):11–15. 83. Schlüter M, Langenstein BA, Thier W, et al. Transesophageal two-dimensional echocardiography in the diagnosis of cor triatriatum in the adult. J Am Coll Cardiol. 1983;2(5): 1011–15. 84. Lengyel M, Arvay A, Bíró V. Two-dimensional echocardiographic diagnosis of cor triatriatum. Am J Cardiol. 1987;59(5):484–5. 85. Modi KA, Annamali S, Ernest K, et al. Diagnosis and surgical correction of cor triatriatum in an adult: combined use of transesophageal and contrast echocardiography, and a review of literature. Echocardiography. 2006;23(6):506–9. 86. Snider AR, Roge CL, Schiller NB, et al. Congenital left ventricular inflow obstruction evaluated by twodimensional echocardiography. Circulation. 1980; 61(4):848–55. 87. Baweja G, Nanda NC, Kirklin JK. Definitive diagnosis of cor triatriatum with common atrium by threedimensional transesophageal echocardiography in an adult. Echocardiography. 2004;21(3):303–6. 88. Beppu S, Nimura Y, Sakakibara H, et al. Mitral cleft in ostium primum atrial septal defect assessed by crosssectional echocardiography. Circulation. 1980;62(5): 1099–107. 89. Wyss CA, Enseleit F, van der Loo B, et al. Isolated cleft in the posterior mitral valve leaflet: a congenital form of mitral regurgitation. Clin Cardiol. 2009;32(10):553–60. 90. Negrea SL, Alexandrescu C, Sabatier M, et al. Cleft posterior mitral valve leaflet in an adult with Turner syndrome diagnosed with the use of 3-dimensional transesophageal echocardiography. Tex Heart Inst J. 2012;39(4):547–9. 91. Zalzstein E, Hamilton R, Zucker N, et al. Presentation, natural history, and outcome in children and adolescents with double orifice mitral valve. Am J Cardiol. 2004;93(8): 1067–9. 92. Das BB, Pauliks LB, Knudson OA, et al. Double-orifice mitral valve with intact atrioventricular septum: an echocardiographic study with anatomic and functional considerations. J Am Soc Echocardiogr. 2005;18(3):231–6. 93. Westendorp IC, de Bruin-Bon HA, Hrudova J. Double orifice mitral valve: a coincidental finding. Eur J Echocardiogr. 2006;7(6):463–4. Epub 2006 Jan 19.

1852


94. Shone JD, Sellers RD, Anderson RC, et al. The developmental complex of “parachute mitral valve,” supravalvular ring of left atrium, subaortic stenosis, and coarctation of aorta. Am J Cardiol. 1963;11:714–25. 95. Bolling SF, Iannettoni MD, Dick M 2nd, et al. Shone’s anomaly: operative results and late outcome. Ann Thorac Surg. 1990;49(6):887–93. 96. Schaverien MV, Freedom RM, McCrindle BW. Independent factors associated with outcomes of parachute mitral valve in 84 patients. Circulation. 2004;109(19):2309–13. 97. Espinola-Zavaleta N, Chugh R, Ramírez GM. Parachute mitral valve with severe mitral regurgitation in an adult patient. Echocardiography. 2012;29(5):E122–5. doi: 10.1111/j.1540-8175.2011.01620.x. Epub 2012 Feb 14. 98. Hakim FA, Kendall CB, Alharthi M, et al. Parachute mitral valve in adults-a systematic overview. Echocardiography. 2010;27(5):581–6. 99. Bonow RO, Carabello BA, Chatterjee K, et al. 2006 Writing Committee Members; American College of Cardiology/ American Heart Association Task Force. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2008;118(15):e523–661. 100. Fernandes SM, Sanders SP, Khairy P, et al. Morphology of bicuspid aortic valve in children and adolescents. J Am Coll Cardiol. 2004;44(8):1648–51. 101. Fernandes SM, Khairy P, Sanders SP, et al. Bicuspid aortic valve morphology and interventions in the young. J Am Coll Cardiol. 2007;49(22):2211–14. 102. Schaefer BM, Lewin MB, Stout KK, et al. Usefulness of bicuspid aortic valve phenotype to predict elastic properties of the ascending aorta. Am J Cardiol. 2007;99(5):686–90. 103. Siniawski H, Grauhan O, Hofmann M, et al. Aortic root abscess and secondary infective mitral valve disease: results of surgical endocarditis treatment. Eur J Cardiothorac Surg. 2005;27(3):434–40. 104. Braverman AC, Güven H, Beardslee MA, et al. The bicuspid aortic valve. Curr Probl Cardiol. 2005;30(9):470–522. 105. Roberts WC. The congenitally bicuspid aortic valve. A study of 85 autopsy cases. Am J Cardiol. 1970;26(1):72–83. 106. Larson EW, Edwards WD. Risk factors for aortic dissection: a necropsy study of 161 cases. Am J Cardiol. 1984;53(6): 849–55. 107. Zoghbi WA, Enriquez-Sarano M, Foster E, et al; American Society of Echocardiography. Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography. J Am Soc Echocardiogr. 2003;16(7):777–802. 108. Keane MG, Wiegers SE, Plappert T, et al. Bicuspid aortic valves are associated with aortic dilatation out of proportion to coexistent valvular lesions. Circulation. 2000;102(19 Suppl 3):III35–9.

109. Thanassoulis G, Yip JW, Filion K, et al. Retrospective study to identify predictors of the presence and rapid progression of aortic dilatation in patients with bicuspid aortic valves. Nat Clin Pract Cardiovasc Med. 2008;5(12):821–8. 110. Singh P, Dutta R, Nanda NC. Live/real time threedimensional transthoracic echocardiographic assessment of bicuspid aortic valve morphology. Echocardiography. 2009;26(4):478–80. 111. Sniecinski RM, Shanewise JS, Glas KE. Transesophageal echocardiography of a unicuspid aortic valve. Anesth Analg. 2009;108(3):788–9. 112. Chu JW, Picard MH, Agnihotri AK, et al. Diagnosis of congenital unicuspid aortic valve in adult population: the value and limitation of transesophageal echocardiography. Echocardiography. 2010;27(9):1107–12. 113. Burri MV, Nanda NC, Singh A, et al. Live/real time threedimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007;24(6):653–5. 114. Roberts WC, Vowels TJ, Ko JM. Natural history of adults with congenitally malformed aortic valves (unicuspid or bicuspid). Medicine (Baltimore). 2012;91(6):287–308. 115. Oliver JM, Gonzalez A, Gallego P, et al. Discrete subaortic stenosis in adults: increased prevalence and slow rate of progression of the obstruction and aortic regurgitation. J Am Coll Cardiol. 2001;38:835–42. 116. Gersony WM. Natural history of discrete subvalvar aortic stenosis: management implications. J Am Coll Cardiol. 2001;38(3):843–5. 117. Doty DB, Eastham CL, Hiratzka LF, et al. Determination of coronary reserve in patients with supravalvular aortic stenosis. Circulation. 1982;66(2 Pt 2):I186–92. 118. Marx, GD. “Repaired” aortic coarctation in adults: not a”simple” congenital heart defect. J Am Coll Cardiol. 2000; 35(4):1003–6. 119. Campbell M. Natural history of coarctation of the aorta. Br Heart J. 1970;32(5):633–40. 120. Hemels ME, Hoendermis ES, van Melle JP, et al. Therapy refractory hypertension in adults: aortic coarctation has to be ruled out. Neth Heart J. 2011;19(3):107–11. 121. Preventza O, Livesay JJ, Cooley DA, et al. Coarctationassociated aneurysms: a localized disease or diffuse aortopathy. Ann Thorac Surg. 2013(May 2);pii: S00034975(13)00643-7. 122. von Kodolitsch Y, Aydin MA, Koschyk DH, et al. Predictors of aneurysmal formation after surgical correction of aortic coarctation. J Am Coll Cardiol. 2002;39(4):617–24. 123. Roifman I, Therrien J, Ionescu-Ittu R, et al. Coarctation of the aorta and coronary artery disease: fact or fiction? Circulation. 2012;126(1):16–21. 124. Nihoyannopoulos P, Karas S, Sapsford RN, et al. Accuracy of two-dimensional echocardiography in the diagnosis of aortic arch obstruction. J Am Coll Cardiol. 1987;10(5): 1072–7. 125. Marx GR, Allen HD. Accuracy and pitfalls of Doppler evaluation of the pressure gradient in aortic coarctation. J Am Coll Cardiol. 1986;7(6):1379–85.


126. Therrien J, Thorne SA, Wright A, et al. Repaired coarctation: a “cost-effective” approach to identify complications in adults. J Am Coll Cardiol. 2000;35(4): 997–1002. 127. Agrawal G, LaMotte LC, Nanda NC, et al. Identification of the Aortic Arch Branches Using Transesophageal Echocardiography. Echocardiography. 1997; 14(5):461–6. 128. Luijendijk P, Bouma BJ, Vriend JW, et al. Usefulness of exercise-induced hypertension as predictor of chronic hypertension in adults after operative therapy for aortic isthmic coarctation in childhood. Am J Cardiol. 2011;108(3):435–9. 129. Buys R, Van De Bruaene A, Müller J, et al. Usefulness of cardiopulmonary exercise testing to predict the development of arterial hypertension in adult patients with repaired isolated coarctation of the aorta. Int J Cardiol. 2013;pii: S0167-5273(13)00231-3. 130. Budoff MJ, Shittu A, Roy S. Use of cardiovascular computed tomography in the diagnosis and management of coarctation of the aorta. J Thorac Cardiovasc Surg. 2013;pii: S0022-5223(13)00052-4. 131. Connolly HM, Huston J 3rd, Brown RD Jr, et al. Intracranial aneurysms in patients with coarctation of the aorta: a prospective magnetic resonance angiographic study of 100 patients. Mayo Clin Proc. 2003;78(12):1491–9. 132. Curtis SL, Bradley M, Wilde P, et al. Results of screening for intracranial aneurysms in patients with coarctation of the aorta. AJNR Am J Neuroradiol. 2012;33(6):1182–6. doi: 10.3174/ajnr.A2915. 133. Martin R, Sellar R, Dawson D. Significant aortic coarctation presenting as subarachnoid hemorrhage in the adult. J Am Coll Cardiol. 2010;55(14):e25. 134. Tan JL, Babu-Narayan SV, Henein MY, et al. Doppler echocardiographic profile and indexes in the evaluation of aortic coarctation in patients before and after stenting. J Am Coll Cardiol. 2005;46(6):1045–53. 135. Graham TP Jr, Bernard Y, Arbogast P, et al. Outcome of pulmonary valve replacements in adults after tetralogy repair: a multi-institutional study. Congenit Heart Dis. 2008;3(3):162–7. 136. Sandor GG, Patterson MW, Tipple M, et al. Left ventricular systolic and diastolic function after total correction of tetralogy of Fallot. Am J Cardiol. 1987;60(14):1148–51. 137. Davlouros PA, Kilner PJ, Hornung TS, et al. Right ventricular function in adults with repaired tetralogy of Fallot assessed with cardiovascular magnetic resonance imaging: detrimental role of right ventricular outflow aneurysms or akinesia and adverse right-to-left ventricular interaction. J Am Coll Cardiol. 2002;40(11):2044–52. 138. Konstantinov IE, Fricke TA, d’Udekem Y, et al. Aortic dissection and rupture in adolescents after tetralogy of Fallot repair. J Thorac Cardiovasc Surg. 2010;140(5): e71–3. 139. Kim WH, Seo JW, Kim SJ, Song J, Lee J, Na CY. Aortic dissection late after repair of tetralogy of Fallot. Int J Cardiol. 2005;101(3):515–16.

1853

140. Rathi VK, Doyle M, Williams RB, Yamrozik J, Shannon RP, Biederman RW. Massive aortic aneurysm and dissection in repaired tetralogy of Fallot; diagnosis by cardiovascular magnetic resonance imaging. Int J Cardiol. 2005;101(1): 169–70. 141. Gatzoulis MA, Balaji S, Webber SA, et al. Risk factors for arrhythmia and sudden cardiac death late after repair of tetralogy of Fallot: a multicentre study. Lancet. 2000;356(9234):975–81. 142. Khairy P, Aboulhosn J, Gurvitz MZ, et al; Alliance for Adult Research in Congenital Cardiology (AARCC). Arrhythmia burden in adults with surgically repaired tetralogy of Fallot: a multi-institutional study. Circulation. 2010;122(9): 868–75. 143. Tei C, Dujardin KS, Hodge DO, et al. Doppler echocardiographic index for assessment of global right ventricular function. J Am Soc Echocardiogr. 1996;9(6): 838–47. 144. Yasuoka K, Harada K, Toyono M, et al. Tei index determined by tissue Doppler imaging in patients with pulmonary regurgitation after repair of tetralogy of Fallot. Pediatr Cardiol. 2004;25(2):131–6. 145. Solarz DE, Witt SA, Glascock BJ, et al. Right ventricular strain rate and strain analysis in patients with repaired tetralogy of Fallot: possible interventricular septal compensation. J Am Soc Echocardiogr. 2004;17(4):338–44. 146. Abd El Rahman MY, Abdul-Khaliq H, Vogel M,et al. Value of the new Doppler-derived myocardial performance index for the evaluation of right and left ventricular function following repair of tetralogy of fallot. Pediatr Cardiol. 2002;23(5):502–7. 147. Meluzín J, Spinarová L, Bakala J, et al. Pulsed Doppler tissue imaging of the velocity of tricuspid annular systolic motion; a new, rapid, and non-invasive method of evaluating right ventricular systolic function. Eur Heart J. 2001;22(4):340–8. 148. Frigiola A, Redington AN, Cullen S, et al. Pulmonary regurgitation is an important determinant of right ventricular contractile dysfunction in patients with surgically repaired tetralogy of Fallot. Circulation. 2004;110:II153–7. 149. Gopal AS, Chukwu EO, Iwuchukwu CJ, et al. Normal values of right ventricular size and function by real time 3-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20(5):445–55. 150. Gatzoulis MA, Clark AL, Cullen S, et al. Right ventricular diastolic function 15 to 35 years after repair of tetralogy of Fallot. Restrictive physiology predicts superior exercise performance. Circulation. 1995;91(6):1775–81. 151. Silversides CK, Veldtman GR, Crossin J, et al. Pressure half-time predicts hemodynamically significant pulmonary regurgitation in adult patients with repaired tetralogy of fallot. J Am Soc Echocardiogr. 2003;16(10):1057–62. 152. Child JS. Echocardiographic assessment of adults with tetralogy of Fallot. Echocardiography. 1993;10(6):629–40. 153. Meijboom F, Szatmari A, Deckers JW, et al. Cardiac status and health-related quality of life in the long term after surgical repair of tetralogy of Fallot in infancy and childhood. J Thorac Cardiovasc Surg. 1995;110(4 Pt 1): 883–91.

1854


154. Hasan BS, Lunze FI, McElhinney DB, et al. Exercise stress echocardiographic assessment of outflow tract and ventricular function in patients with an obstructed right ventricular-to-pulmonary artery conduit after repair of conotruncal heart defects. Am J Cardiol. 2012;110(10): 1527–33. 155. Brown DW, McElhinney DB, Araoz PA, et al. Reliability and accuracy of echocardiographic right heart evaluation in the U.S. Melody Valve Investigational Trial. J Am Soc Echocardiogr. 2012;25(4):383–392.e4. 156. Lurz P, Gaudin R, Taylor AM, et al. Percutaneous pulmonary valve implantation. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2009;:112–17. 157. Markiewicz W, Sechtem U, Kirby R, et al. Measurement of ventricular volumes in the dog by nuclear magnetic resonance imaging. J Am Coll Cardiol. 1987;10(1):170–7. 158. Sechtem U, Pflugfelder PW, Gould RG, et al. Measurement of right and left ventricular volumes in healthy individuals with cine MR imaging. Radiology. 1987;163(3):697–702. 159. Buechel ER, Dave HH, Kellenberger CJ, et al. Remodelling of the right ventricle after early pulmonary valve replacement in children with repaired tetralogy of Fallot: assessment by cardiovascular magnetic resonance. Eur Heart J. 2005;26(24):2721–7. 160. Therrien J, Siu SC, McLaughlin PR, et al. Pulmonary valve replacement in adults late after repair of tetralogy of fallot: are we operating too late? J Am Coll Cardiol. 2000;36(5):1670–5. 161. Discigil B, Dearani JA, Puga FJ, et al. Late pulmonary valve replacement after repair of tetralogy of Fallot. J Thorac Cardiovasc Surg. 2001;121(2):344–51. 162. Adamson L, Vohra HA, Haw MP. Does pulmonary valve replacement post repair of tetralogy of Fallot improve right ventricular function? Interact Cardiovasc Thorac Surg. 2009;9(3):520–7. 163. Meijboom FJ, Roos-Hesselink JW, McGhie JS, et al. Consequences of a selective approach toward pulmonary valve replacement in adult patients with tetralogy of Fallot and pulmonary regurgitation. J Thorac Cardiovasc Surg. 2008;135(1):50–5. 164. Mustard WT. Successful two-stage correction of transposition of the great vessels. Surgery. 1964;55:469–72. 165. Senning A. Surgical correction of transposition of the great vessels. Surgery. 1959;45(6):966–80. 166. Moons P, Gewillig M, Sluysmans T, et al. Long term outcome up to 30 years after the Mustard or Senning operation: a nationwide multicentre study in Belgium. Heart. 2004;90(3):307–13. 167. Bottega NA, Silversides CK, Oechslin EN, et al. Stenosis of the superior limb of the systemic venous baffle following a Mustard procedure: an under-recognized problem. Int J Cardiol. 2012;154(1):32–7. 168. Smallhorn JF, Gow R, Freedom RM, et al. Pulsed Doppler echocardiographic assessment of the pulmonary venous pathway after the Mustard or Senning procedure for transposition of the great arteries. Circulation. 1986; 73(4):765–74.

169. Roche SL, Silversides CK, Oechslin EN. Monitoring the patient with transposition of the great arteries: arterial switch versus atrial switch. Curr Cardiol Rep. 2011;13(4):336–46. 170. Kaulitz R, Stümper OF, Geuskens R, et al. Comparative values of the precordial and transesophageal approaches in the echocardiographic evaluation of atrial baffle function after an atrial correction procedure. J Am Coll Cardiol. 1990;16(3):686–94. 171. Ahmed S, Nekkanti R, Nanda NC, et al. Three-dimensional transesophageal echocardiographic demonstration of intraatrial baffle obstruction. Echocardiography. 2003; 20(7):683–6. 172. Enar S, Singh P, Douglas C, et al. Live/real time threedimensional transthoracic echocardiographic assessment of transposition of the great arteries in the adult. Echocardiography. 2009;26(9):1095–104. 173. Derrick GP, Narang I, White PA, et al. Failure of stroke volume augmentation during exercise and dobutamine stress is unrelated to load-independent indexes of right ventricular performance after the Mustard operation. Circulation. 2000;102:III154–9. 174. Armstrong EJ, Kwa AT, Bhat A, et al. Intracardiac echocardiography to guide percutaneous closure of atrial baffle defects. J Invasive Cardiol. 2012; 24(9):473–6. 175. Khattab K, Schmidheiny P, Wustmann K, et al. Echocardiogram versus cardiac magnetic resonance imaging for assessing systolic function of subaortic right ventricle in adults with complete transposition of great arteries and previous atrial switch operation. Am J Cardiol. 2013; 111(6):908–13. 176. Jatene AD, Fontes VF, Paulista PP, et al. Anatomic correction of transposition of the great vessels. J Thorac Cardiovasc Surg. 1976;72(3):364–70. 177. Schwartz ML, Gauvreau K, del Nido P, et al. Long-term predictors of aortic root dilation and aortic regurgitation after arterial switch operation. Circulation. 2004;110(11 Suppl 1):II128–32. 178. Rastelli GC, Wallace RB, Ongley PA. Complete repair of transposition of the great arteries with pulmonary stenosis. A review and report of a case corrected by using a new surgical technique. Circulation. 1969;39(1):83–95. 179. Beauchesne LM, Warnes CA, Connolly HM, et al. Outcome of the unoperated adult who presents with congenitally corrected transposition of the great arteries. J Am Coll Cardiol. 2002;40(2):285–90. 180. Graham TP Jr, Bernard YD, Mellen BG, et al. Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study. J Am Coll Cardiol. 2000;36(1):255–61. 181. Prieto LR, Hordof AJ, Secic M, et al. Progressive tricuspid valve disease in patients with congenitally corrected transposition of the great arteries. Circulation. 1998; 98(10):997–1005. 182. Van Praagh R, Papagiannis J, Grünenfelder J, et al. Pathologic anatomy of corrected transposition of the great arteries: medical and surgical implications. Am Heart J. 1998;135(5 Pt 1):772–85.


183. Allwork SP, Bentall HH, Becker AE, et al. Congenitally corrected transposition of the great arteries: morphologic study of 32 cases. Am J Cardiol. 1976;38(7):910–23. 184. Connelly MS, Liu PP, Williams WG, et al. Congenitally corrected transposition of the great arteries in the adult: functional status and complications. J Am Coll Cardiol. 1996;27(5):1238–43. 185. Huhta JC, Maloney JD, Ritter DG, et al. Complete atrioventricular block in patients with atrioventricular discordance. Circulation. 1983;67(6): 1374–7. 186. van Son JA, Danielson GK, Huhta JC, et al. Late results of systemic atrioventricular valve replacement in corrected transposition. J Thorac Cardiovasc Surg. 1995;109(4):642– 52; discussion 652. 187. Marcelletti C, McGoon DC, Mair DD. The natural history of truncus arteriosus. Circulation. 1976;54(1):108–11. 188. Di Donato RM, Fyfe DA, Puga FJ, et al. Fifteen-year experience with surgical repair of truncus arteriosus. J Thorac Cardiovasc Surg. 1985;89(3):414–22. 189. Van Praagh R, Van Praagh S. The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications. A study of 57 necropsy cases. Am J Cardiol. 1965;16(3):406–25. 190. Vitarelli A, Gheorghiade M, Gentile R, et al. Echocardiographic features of truncal abnormalities. Special emphasis to the evaluation of pulmonary arteries. G Ital Cardiol. 1984;14(4):245–52. 191. Vargas Barron J, Sahn DJ, Attie F, et al. Two-dimensional echocardiographic study of right ventricular outflow and great artery anatomy in pulmonary atresia with ventricular septal defects and in truncus arteriosus. Am Heart J. 1983;105(2):281–6. 192. Williams JM, de Leeuw M, Black MD, Freedom RM, Williams WG, McCrindle BW. Factors associated with outcomes of persistent truncus arteriosus. J Am Coll Cardiol. 1999;34(2):545–53. 193. McGoon DC, Rastelli GC, Ongley PA. An operation for the correction of truncus arteriosus. JAMA. 1968;205(2):69–73. 194. Vohra HA, Whistance RN, Chia AX, et al. Long-term follow-up after primary complete repair of common arterial trunk with homograft: a 40-year experience. J Thorac Cardiovasc Surg. 2010;140(2):325–9. 195. Russell HM, Pasquali SK, Jacobs JP, et al. Outcomes of repair of common arterial trunk with truncal valve surgery: a review of the society of thoracic surgeons congenital heart surgery database. Ann Thorac Surg. 2012;93(1):164–9; discussion 169. 196. Rajasinghe HA, McElhinney DB, Reddy VM, et al. Longterm follow-up of truncus arteriosus repaired in infancy: a twenty-year experience. J Thorac Cardiovasc Surg. 1997;113(5):869–78; discussion 878–9.

1855

197. Henaine R, Azarnoush K, Belli E, et al. Fate of the truncal valve in truncus arteriosus. Ann Thorac Surg. 2008; 85(1):172–8. 198. Shetty AV, Martin R. Double outlet right ventricle with pulmonary stenosis. Br Heart J. 1967;29(2):279–81. 199. Mahle WT, Martinez R, Silverman N, et al. Anatomy, echocardiography, and surgical approach to double outlet right ventricle. Cardiol Young. 2008;18 Suppl 3:39–51. 200. Brown JW, Ruzmetov M, Okada Y, et al. Surgical results in patients with double outlet right ventricle: a 20-year experience. Ann Thorac Surg. 2001;72(5):1630–5. 201. Soszyn N, Fricke TA, Wheaton GR, et al. Outcomes of the arterial switch operation in patients with Taussig-Bing anomaly. Ann Thorac Surg. 2011;92(2):673–9. 202. Ito D, Shiraishi J, Noritake K, et al. Multidetector computed tomography demonstrates double-inlet, double-outlet right ventricle. Intern Med. 2011;50(18):2053–4. 203. Saleeb SF, Juraszek A, Geva T. Anatomic, imaging, and clinical characteristics of double-inlet, double-outlet right ventricle. Am J Cardiol. 2010;105(4):542–9. 204. Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax. 1971;26(3):240–8. 205. Gentles TL, Mayer JE Jr, Gauvreau K, et al. Fontan operation in five hundred consecutive patients: factors influencing early and late outcome. J Thorac Cardiovasc Surg. 1997;114(3):376–91. 206. DiSessa TG, Child JS, Perloff JK, et al. Systemic venous and pulmonary arterial flow patterns after Fontan’s procedure for tricuspid atresia or single ventricle. Circulation. 1984;70(5):898–902. 207. Tsang W, Johansson B, Salehian O, et al. Intracardiac thrombus in adults with the Fontan circulation. Cardiol Young. 2007;17(6):646–51. 208. Marrone C, Galasso G, Piccolo R, et al. Antiplatelet versus anticoagulation therapy after extracardiac conduit Fontan: a systematic review and meta-analysis. Pediatr Cardiol. 2011;32(1):32–9. 209. Marelli AJ, Child JS, Perloff JK. Transesophageal echocardiography in congenital heart disease in the adult. Cardiol Clin. 1993;11(3):505–20. 210. Fyfe DA, Kline CH, Sade RM, et al. Transesophageal echocardiography detects thrombus formation not identified by transthoracic echocardiography after the Fontan operation. J Am Coll Cardiol. 1991;18(7):1733–7. 211. Mart CR. Three-dimensional echocardiographic evaluation of the Fontan conduit for thrombus. Echocardiography. 2012;29(3):363–8. 212. Markl M, Geiger J, Kilner PJ, et al. Time-resolved threedimensional magnetic resonance velocity mapping of cardiovascular flow paths in volunteers and patients with Fontan circulation. Eur J Cardiothorac Surg. 2011;39(2): 206–12.

CHAPTER 76 Echocardiographic Evaluation for Acquired Heart Diseases in Childhood Jie Sun, Rula Balluz, Lindsay Rogers, Shuping Ge

Snapshot ¾¾ Infective Endocarditis ¾¾ Modified Duke Criteria for the Diagnosis of Infective

Endocarditis ¾¾ Echocardiographic Findings ¾¾ Complications of Infective Endocarditis

INTRODUCTION As with congenital heart disease, acquired heart diseases are also common in children. The spectrum includes infective endocarditis, rheumatic heart disease (RHD), Kawasaki disease, and other cardiovascular involvement related to other systems or organs, such as hypertension, sickle cell disease, chronic renal disease, and cancer survivors. Echocardiographic diagnosis and assessment have become a routine practice to evaluate these patients initially and possibly longitudinally to facilitate diagnosis, prognosis, and guidance for treatment. In this chapter, we will discuss three of the most common acquired cardiovascular diseases in children, namely, infective endocarditis, RHD, and Kawasaki disease, and further in-depth discussion can be found in comprehensive texts and other sources.

INFECTIVE ENDOCARDITIS Infective endocarditis (IE) is an uncommon but lifethreatening infection. Despite advances in diagnosis, antimicrobial therapy, surgical techniques, and manage ment of complications, patients with IE still have high morbidity and mortality rates related to this condition.

¾¾ Rheumatic Heart Disease ¾¾ Jones Criteria, Updated 1992 ¾¾ Kawasaki Disease ¾¾ Coronary Ectasia and Aneurysms by Echocardiography

IE can happen on normal heart or abnormal heart. The patients with certain conditions are at increased risk to develop IE, such as congenital heart disease, acquired heart disease, indwelling catheters, intracardiac devices, prostheses, immunodeficiency, and intravenous drug abuse. The true incidence of IE in pediatric population or adults is unknown. IE accounts for about 1 in 1,280 pediatric admissions per year.1 The vegetation can occur on valve leaflets, the walls, chordae, paraprosthetic tissue, shunts, or conduits. There is an increased proportion in repaired congenital heart disease due to increased population in this group. The clinical diagnosis of IE is based upon a combination of clinical features, positive blood culture, and evidence of vegetation by imaging or pathology. Turbulent blood flow produced by congenital or acquired heart disease, such as flow from high- to low-pressure chambers or across a narrowed orifice, traumatizes the endothelium. This creates a predisposition for deposition of platelets and fibrin on the surface of the endothelium, which results in nonbacterial thrombotic endocarditis. Invasion of the bloodstream with a microbial

Chapter 76: Echocardiographic Evaluation for Acquired Heart Diseases in Childhood

species that has the pathogenic potential to colonize this site can then result in IE. Bacteria can be entrapped and colonize to initiate focus of infection; platelets and fibrin are deposited forming vegetation. It almost always involves a valve and can cause significant valve insufficiency or perforation. Its complications include congestive heart failure, embolization, abscess, heart block, mycotic aneurysm, pericarditis, or myocarditis. Subacute presentation of IE is the more common type. Its presentation can be insidious, nontoxic, and with immune phenomena. The most common pathogen is viridans strep; other pathogens such as fungal, HACEK group, and coagulase-negative Staphylococcus aureus can also be the cause of subacute cases. The extracardiac manifestations can be splenomegaly, hematuria, immune phenomena including Roth spot, splinter hemorrhages, Janeway lesion, and Osler node. The extracardiac manifestation in children with subacute IE is less common than in adults. The patients with acute presentation of IE can present with high fever and appear very toxic. The acute IE mostly happens in postoperative patients or patients with an indwelling catheter. The most common cause of acute IE is Staphylococcus aureus. The clinical diagnosis of IE is established based on the modified Duke criteria.2 Two major or one major and three minor criteria or five minors are required to establish a diagnosis of IE. The pathological criteria for IE include micro-organism demonstrated by culture or histology of a vegetation, or in a vegetation that has embolized, or in an intracardiac abscess or pathological lesions—vegetation or intracardiac abscess—confirmed by histology showing active IE.

MODIFIED DUKE CRITERIA FOR THE DIAGNOSIS OF INFECTIVE ENDOCARDITIS Major Criteria Positive Blood Culture for Infective Endocarditis •

Typical micro-organism for infective endocarditis from two separate blood cultures: Viridans streptococci, Staphylococcus aureus, Streptococcus bovis, HACEK group (Hemophilus spp. Actinobacillus actinomycete mcomitans, Cardiobacterium hominis, Eikenella spp., and Kingella kingae) or

• •

•

1857

Community-acquired enterococci, in the absence of a primary focus Persistently positive blood culture, defined as recovery of a micro-organism consistent with infective endocarditis from blood cultures drawn more than 12 hours apart or all of three or a majority of four or more separate blood cultures, with first and last drawn at least 1 hour apart Single positive blood culture for Coxiella burnetti or phase I antibody titer > 1:800.

Evidence of Endocardial Involvement Positive Echocardiogram for Infective Endocarditis: • Transesophageal echocardiography (TEE) recom mended as first test in the following patients: (a) prosthetic valve endocarditis; or (b) those with at least “possible” IE by clinical criteria; or (c) those with suspected complicated IE such as paravalvular abscess. Transthoracic echocardiography (TTE) recommended as first test in all other patients. • Definition of positive findings: Oscillating intracardiac mass, on valve or supporting structures, or in the path of regurgitant jets, or on implanted material, in the absence of an alternative anatomical explanation or myocardial abscess or new partial dehiscence of prosthetic valve. New valvular regurgitation: Increase or change in preexisting murmur not sufficient. Minor Criteria: • Predisposing heart condition or intravenous drug use • Fever ≥ 38.0°C (100.4°F) • Vascular phenomena: Major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, and Janeway lesions • Immunological phenomena: Glomerulonephritis, Osler’s nodes, Roth spots, and rheumatoid factor • Positive blood culture not meeting major criterion as noted previously (excluding single positive cultures for coagulase-negative Staphylococci and organisms that do not cause endocarditis) or serological evidence of active infection with organism consistent with infective endocarditis.

ECHOCARDIOGRAPHIC FINDINGS Echocardiography should be performed in any patient sus pected of having IE to allow earlier diagnosis, treatment,

1858


and prevent complications. The echocardiographic appear ance of vegetations, noninfectious thrombi, and other intracardiac masses may be indistinguishable. The incidental echocardiographic finding of a mass in a patient who has no associated clinical suspicion of IE likely warrants further investigation and follow-up but should not be considered a vegetation without supporting clinical features. The accuracy of TTE for detecting vegetations in IE has been evaluated in a variety of studies. Studies show that TTE had a mean sensitivity of 79% for the detection of vegetations.3 There is generally good agreement between the location and identity of large vegetations on TTE and pathological findings from autopsy or surgery.4 The role of the more invasive and expensive TEE in the diagnosis of IE stems from its high sensitivity in detecting and defining valve vegetations. The sensitivity of TEE is substantially higher (above 90%) than the values achieved with the transthoracic approach.5

Vegetation Location The morphology of IE vegetations is dependent on the location of the endothelial lesion and always follows the “pathological” bloodstream. When IE occurs in association with ventricular septal defect, the vegetation is typically visualized on the right ventricular aspect of the septum and/or on the site where the high-velocity jet strikes the right ventricular free wall. In the case of patent ductus arteriosus, the vegetation may float through the pulmonary artery. In patients with regurgitation of atrioventricular valves, the vegetation is located on the atrial side

Fig. 76.1: Mitral valve vegetation. A vegetation involves the posterior leaflet of mitral valve (white arrow). A perforation with color flow signals moving through it is noted (red arrow). Mitral valve insufficiency is present (yellow arrow). This patient had cerebral embolism.

(Fig. 76.1). When the aortic valve is affected, perforation through the annulus into the myocardium or into either atria is possible. Newly acquired AV block together with clinical suspicion of IE may be a strong indicator for the presence of para-aortic ring abscess. Heart conditions most associated with IE were unrepaired ventricular septal defect, mitral regurgitation, and bicuspid aortic valve.6 In patients who undergo palliative surgery, infected aorta to pulmonary artery shunts predominate. In those who have corrective surgery, the most common sites for developing IE include right ventricle to pulmonary artery valved conduits, prosthetic valves, and ventricular septal defect patch closure. Patients with indwelling catheters such as central lines can also develop line infection or associated vegetation (Fig. 76.2).

Vegetation Size and Embolic Risk In general, a larger vegetation size appears to be predictive of embolic risk. In a study of 105 patients with IE, patients with a vegetation diameter above 10 mm had a significantly higher incidence of embolic events than did those with smaller vegetations (47 vs 19%, P < 0.01).7 The association was particularly strong in patients with mitral valve endocarditis. Vegetation size did not appear to predict other complications such as severe heart failure and death and was not related to the location of endocarditis or type of organism. A series of 211 patients with 28 embolic events found that vegetation size was associated with embolic risk for staphylococcus and mitral valve vegetations, but was not

Fig. 76.2: Inferior vena cava (IVC) vegetation. IVC vegetation (black arrow) in a patient who had an indwelling central line causing direct trauma of endothelium.


associated with embolic risk for streptococcus or aortic vegetations.8 Vegetation mobility confers incremental risk beyond vegetation size. In a series of 178 patients with definite IE who underwent TEE, the incidence of embolism, as diagnosed by cerebral and thoracoabdominal CT scans, was higher when vegetation size was ≥ 15 mm and when the vegetation was moderately or severely mobile (62 vs 20% for low mobility).9 Embolic events were particularly frequent when both severely mobile and very large vegetations were present. Embolic risk generally falls with time after institution of appropriate antibiotic therapy.

COMPLICATIONS OF INFECTIVE ENDOCARDITIS In addition to its role in diagnosing IE, echocardiography is important for recognizing the intracardiac complications associated with IE including regurgitant valve lesions, chordal rupture, valve perforation, prosthetic dehiscence, and paravalvular leak. Vegetations may also extend to the outside of valve into surrounding structures to cause abscess, fistula, or pseudoaneurysm formation.

Negative Result The implications of an initial TEE examination that fails to show vegetations in a patient with suspected IE should be carefully considered. Although TEE cannot definitively rule out IE, its high diagnostic sensitivity results in a low probability of the disease when negative results are obtained in a patient with an intermediate likelihood of the disease. However, repeat examination is important, particularly in patients at high risk for IE. Although the rate of false-negative TEE examinations in patients with IE is low, negative results confer an obligation of careful followup with exercise of sound clinical judgment.

Infective Endocarditis Prophylaxis Recommended for Invasive Dental Procedure10 •

Prosthetic cardiac valve or prosthetic material used for cardiac valve repair • Previous IE • Unrepaired cyanotic congenital heart defect (CHD), including palliative shunts and conduits • Completely repaired congenital heart defect with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure† • Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization) • Cardiac transplantation recipients who develop cardiac valvulopathy Except for the conditions listed above, antibiotic prophylaxis is no longer recommended for any other form of CHD.

RHEUMATIC HEART DISEASE Rheumatic fever is an acute inflammatory illness that occurs following an upper respiratory infection with group A b-hemolytic streptococci (GAS). Rheumatic fever particularly affects children 5–15 years old. It is the most common form of acquired heart disease in children and young adults throughout the world. It is a rare disease in the United States. However, several outbreaks were reported in certain geographical areas.11 The treatment of strep pharyngitis shifts to nonrheumatogenic strains of GAS. Its presentation is less classic. The significance of rheumatic fever is chronic rheumatic valvar disease including mitral regurgitation, aortic regurgitation, mitral stenosis, or aortic stenosis. It usually takes over decades from valvar regurgitation to valvar stenosis.

JONES CRITERIA, UPDATED 199212

Infective Endocarditis Prophylaxis In patients with underlying cardiac conditions associated with the highest risk of adverse outcome from IE, IE prophylaxis for dental procedure is reasonable. In patients with conditions associated with the highest risk of adverse outcome from endocarditis, giving prophylaxis for dental procedures is reasonable. †

1859

Major Criteria • • • • •

Carditis Polyarthritis Chorea Erythema marginatum Subcutaneous nodules

Prophylaxis is reasonable because endothelialization of prosthetic material occurs within 6 months after the procedure.

1860


Minor Criteria • Arthralgia • Fever • Elevated acute phase reactants • Erythrocyte sedimentation rate • C-reactive protein • Prolonged PR interval Plus supporting evidence of an antecedent group A streptococcal infection: • Positive throat culture or rapid strep test • Elevated or rising streptococcal antibody titers

Aortic regurgitation occurs in approximately 20–25% of patients with acute rheumatic carditis, usually in combination with mitral regurgitation. Isolated aortic regurgitation occurs in approximately 5% of patients with acute rheumatic carditis14 (Fig. 76.4).

Chronic Rheumatic Heart Disease

The mitral valve is the predominant valve affected during acute carditis.13 Characteristic changes include annular dilation and chordal elongation, leading to prolapse of the anterior leaflet. As a result, the leaflets no longer coapt appropriately and there is a regurgitant orifice. In rheumatic carditis, the regurgitant jet is typically directed toward the posterolateral wall of the left atrium, causing thickening and calcification of the endocardium (Fig. 76.3). It is important to differentiate rheumatic mitral prolapse from mitral prolapse seen in Barlow’s syndrome. In rheumatic fever mitral carditis, only the coapting portion of the anterior leaflet prolapses and there is no billowing of the medial portion. In contrast, billowing of the posterior or both leaflets of the mitral valve occurs in Barlow’s syndrome (mitral valve prolapse). Another differentiating feature is that chordal rupture frequently occurs with Barlow’s syndrome, but rarely in patients with rheumatic mitral valve disease.

Chronic mitral regurgitation is the most common form of RHD in children and adults. Mitral valve stenosis usually occurs in the third to fifth decade of life.15 The natural history of rheumatic mitral valve disease can begin with regurgitation, to complete resolution of regurgitation without evidence of heart disease, and then on to later development of clinically significant mitral stenosis, and/or regurgitation when patients reach adulthood.16 Characteristic changes occur to the mitral valve apparatus in rheumatic fever, including thickening and the scarring of the valve leaflets, commissures, and chordae tendineae. Fusion of the mitral cusps and chordae tendineae leads to thickening and shortening of these structures, resulting in a mitral orifice that is restricted in size and shaped like a funnel. Women are more likely than men to develop rheumatic mitral stenosis.17 On echocardiography, patients with rheumatic mitral stenosis have thickened echodense leaflets, commissural and/or chordal fusion, and abnormal diastolic leaflet excursion resulting in a bent knee or hockey stick appearance of the anterior leaflet. Mitral stenosis and regurgitation may coexist.

Fig. 76.3: Mitral valve insufficiency. Mitral valve insufficiency (white arrow) in a patient with acute rheumatic heart disease.

Fig. 76.4: Aortic insufficiency. Aortic insufficiency (white arrow) in a patient with acute rheumatic heart disease.

Acute Valvulitis


Like mitral valve stenosis, aortic valve stenosis is a form of chronic RHD and occurs about 20–40 years after the initial acute illness. On echocardiography, imaging of chronic rheumatic aortic valve stenosis demonstrates thickened leaflets with variable degrees of commissural fusion and leaflet retraction. Dooming of the leaflets, increased echogenicity, and restricted motion present as aortic valve stenosis progresses.

KAWASAKI DISEASE Kawasaki disease is an acute, self-limited vasculitis that occurs predominantly in infants and young children. It was first described in Japan in l967 by Tomisaku Kawasaki. The disease is now known to occur in both endemic and community-wide epidemic forms in the Americas, Europe, and Asia in all races. Kawasaki disease is characterized by fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develop in approximately 15–25% of untreated children with the disease and may lead to myocardial infarction, sudden death, or ischemic heart disease.18–20 In the United States, Kawasaki disease is the leading cause of acquired heart disease in children. Treatment of Kawasaki disease in the acute phase is directed at reducing inflammation in the coronary artery wall and preventing coronary thrombosis. The long-term therapy in individuals who develop coronary aneurysms is aimed at preventing myocardial ischemia or infarction. The etiology of Kawasaki disease remains unknown, although clinical and epidemiological features strongly suggest an infectious cause. It also is possible that Kawasaki disease results from an immunological response that is triggered by any of several different microbial agents. Kawasaki disease is a generalized systemic vasculitis involving blood vessels throughout the body. Aneurysms may occur in other extraparenchymal muscular arteries. The early stages in the formation and development of arteritis in Kawasaki disease have been well studied morphologically in relatively large muscular arteries.21 Cardiovascular manifestations can be prominent in the acute phase of Kawasaki disease and are the leading cause of long-term morbidity and mortality in these patients. During this acute phase, the pericardium, myocardium, endocardium, valves, and coronary arteries may all be involved.

1861

CORONARY ECTASIA AND ANEURYSMS BY ECHOCARDIOGRAPHY The major sequelae of Kawasaki disease are related to the coronary arterial system. Cardiac imaging is critical for the evaluation of all patients with suspected Kawasaki disease. It requires serial echocardiograms. The initial echocardiogram should be performed as soon as the diagnosis is suspected, but initiation of treatment should not be delayed by the timing of the study. This initial study establishes a baseline for longitudinal follow-up of coronary artery morphology, cardiac function, and the evolution and resolution of pericardial effusion when present. Two-dimensional (2D) imaging should be performed with the highest frequency transducer possible. These probes allow for higher-resolution and detailed evaluation of the coronary arteries. The focus should be on imaging the left main coronary artery (LMCA), left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX), and right coronary artery (RCA). Common sites of coronary aneurysms include the proximal LAD and proximal RCA, followed by the LMCA, then LCX, and finally the distal RCA and the junction between the RCA and posterior descending coronary artery22 (Figs 76.5 to 76.7). In addition to measuring coronary artery dimensions, imaging the coronary arteries also may reveal the lack of normal tapering and perivascular echogenicity or “brightness”.23

Fig. 76.5: Left main coronary artery (LMCA; white arrow) and left anterior descending artery (LAD; red arrow) ectasia in a patient with Kawasaki disease without aneurysm.

1862


Table 76.1: Echocardiographic Views of Coronary Arteries in Patients with Kawasaki Disease

Left main coronary artery: Precordial short-axis at level of aortic valve; precordial long-axis of left ventricle (superior tangential); subcostal left ventricular long-axis Left anterior descending coronary artery: Precordial short-axis at level of aortic valve; precordial superior tangential long-axis of left ventricle; precordial short-axis of left ventricle Left circumflex: Precordial short-axis at level of aortic valve; apical four-chamber Right coronary artery, proximal segment: Precordial short-axis at level of aortic valve; precordial long-axis (inferior tangential) of left ventricle; subcostal coronal projection of right ventricular outflow tract; subcostal short-axis at level of atrioventricular groove Right coronary artery, middle segment: Precordial long-axis of left ventricle (inferior tangential); apical four-chamber; subcostal left ventricular long axis; subcostal short-axis at level of atrioventricular groove Right coronary artery, distal segment: Apical four-chamber (inferior); subcostal atrial long-axis (inferior) Posterior descending coronary artery: Apical four-chamber (inferior); subcostal atrial long-axis (inferior); precordial long-axis (inferior tangential) imaging posterior interventricular groove

Fig. 76.6: Left main coronary artery (LMCA; white arrow) and left anterior descending artery (LAD; yellow arrow) ectasia and early aneurysm near the bifurcation (red arrow) in a patient with Kawasaki disease.

Fig. 76.7: Right coronary artery aneurysm (white arrow) in a patient with history of Kawasaki disease.

The most commonly used view is the parasternal shortaxis at the level of the aortic root. However, a compre hensive study of both the left and right coronary arteries and their branches should be performed from parasternal, four-chamber, and subcostal views to ascertain full evaluation of the coronary system (Table 76.1). The coronary arteries should be measured by 2D echocardiography from inner edge to inner edge excluding points of branching. Particular attention should be paid to describe coronary abnormalities, including ectasia, aneurysm, or intraluminal thrombi. When a coronary artery is larger than normal (dilated) without a segmental aneurysm, the vessel is considered ectatic. The use of z scores are available for the LMCA, proximal LAD, and proximal RCA. Aneurysms are classified as saccular if

axial and lateral diameters are nearly equal or as fusiform if symmetric dilatation with gradual proximal and distal tapering is seen. In the United States, aneurysms were classified as small (< 5 mm internal diameter), medium (5–8 mm internal diameter), or giant (> 8 mm internal diameter). The Japanese Ministry of Health criteria classify coronary arteries as abnormal if the internal lumen diameter is > 3 mm in children < 5 years old or > 4 mm in children ≥ 5 years old; if the internal diameter of a segment measures ≥ 1.5-times that of an adjacent segment; or if the coronary lumen is clearly irregular.22 In addition, assessment of left ventricle (LV) function should be a part of the echocardiographic evaluation of all patients with suspected Kawasaki disease. LV enddiastolic and end-systolic dimensions and a shortening


fraction should be measured from standard M-mode tracings. Apical imaging allows the estimation of LV end-diastolic and end-systolic volumes and an ejection fraction. Evaluating regional wall motion may be useful, especially in children with coronary artery abnormalities using routine as well as stress. Standard pulsed and color flow Doppler interrogation should be performed to assess the presence and degree of valvular regurgitation (in particular for mitral and aortic valves). Finally, the presence of pericardial effusion should be evaluated as a part of routine evaluation. For follow-up studies in patients with Kawasaki disease, echocardiographic evaluation should be routinely per formed at the time of diagnosis, at 2 weeks, and at 6–8 weeks after onset of the disease. It is debatable if repeat echocardio graphy should be performed 1 year after the onset of the illness in patients in whom the echocardiographic findings are normal at 4–8 weeks. Follow-up echocardiograms should identify the progression or regression of coronary abnormalities, evaluate ventricular and valvular function, and assess the presence or evolution of pericardial effusions. It is important to recognize the limitations of echo cardiography in the evaluation and follow-up of patients with Kawasaki disease. Although echocardiographic detection of thrombi and coronary artery stenosis has been reported, the sensitivity and specificity of echocardiography for identifying these abnormalities is unclear. In addition, the visualization of coronary arteries becomes progressively more difficult as a child grows and body size increases. Angiography, intravascular ultrasound (IVUS), TEE, and other modalities including magnetic resonance angiography (MRA) and ultrafast computed tomography (CT) may be of value in the assessment of selected patients.22

REFERENCES 1. Van Hare GF, Ben-Shachar G, Liebman J, et al. Infective endocarditis in infants and children during the past 10 years: a decade of change. Am Heart J. 1984;107(6): 1235–40. 2. Li JS, Sexton DJ, Mick N, et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis. 2000;30(4):633–8. 3. O’Brien JT, Geiser EA. Infective endocarditis and echo cardiography. Am Heart J. 1984;108(2):386–94. 4. Gilbert BW, Haney RS, Crawford F, et al. Two-dimensional echocardiographic assessment of vegetative endocarditis. Circulation. 1977;55(2):346–53.

1863

5. Shively BK, Gurule FT, Roldan CA, et al. Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis. J Am Coll Cardiol. 1991;18(2):391–7. 6. Di Filippo S, Delahaye F, Semiond B, et al. Current patterns of infective endocarditis in congenital heart disease. Heart. 2006;92(10):1490–5. 7. Mügge A, Daniel WG, Frank G, et al. Echocardiography in infective endocarditis: reassessment of prognostic implications of vegetation size determined by the transthoracic and the transesophageal approach. J Am Coll Cardiol. 1989;14(3):631–8. 8. Vilacosta I, Graupner C, San Román JA, et al. Risk of embolization after institution of antibiotic therapy for infective endocarditis. J Am Coll Cardiol. 2002;39(9): 1489–95. 9. Di Salvo G, Habib G, Pergola V, et al. Echocardiography predicts embolic events in infective endocarditis. J Am Coll Cardiol. 2001;37(4):1069–76. 10. Walter Wilson, Kathryn A Taubert, Michael Gewitz, et al. Prevention of Infective Endocarditis. Circulation. 2007;116:1736–54. 11. Veasy LG, Tani LY, Hill HR. Persistence of acute rheumatic fever in the intermountain area of the United States. J Pediatr. 1994;124(1):9–16. 12. Dajani AS, Ayoub E, Burman FZ, et al. Secial Writing Group of the Committee on Rheumatic fever, Endicarditis, and Kawasaki of the American Heart Association. Guidelines for the diagnosis of rheumatic fever. Jones Criteria. 1992 update. JAMA. 1992:268:2069–73. 13. Zhou LY, Lu K. Inflammatory valvular prolapse produced by acute rheumatic carditis: echocardiographic analysis of 66 cases of acute rheumatic carditis. Int J Cardiol. 1997;58(2):175–8. 14. Arora R, Subramanyam G, Khalilullah M, et al. Clinical profile of rheumatic fever and rheumatic heart disease: a study of 2,500 cases. Indian Heart J. 1981;33(6):264–9. 15. Horstkotte D, Niehues R, Strauer BE. Pathomorphological aspects, aetiology and natural history of acquired mitral valve stenosis. Eur Heart J. 1991;12 Suppl B:55–60. 16. Virmani R, Farb A, Burke AP, et al. Pathology of acute rheumatic carditis. In: Narula J, Virmani R, Reddy KS, Tandon R, editors. Rheumatic Fever. Washington, DC: American Registry of Pathology Press;1999:221. 17. Stollerman GH. Rheumatic fever in the 21st century. Clin Infect Dis. 2001;33(6):806–14. 18. Kato H, Sugimura T, Akagi T, et al. Long-term consequences of Kawasaki disease. A 10- to 21-year follow-up study of 594 patients. Circulation. 1996;94:1379–85. 19. Dajani AS, Taubert KA, Gerber MA, et al. Diagnosis and therapy of Kawasaki disease in children. Circulation. 1993;87:1776–80. 20. Taubert KA, Rowley AH, Shulman ST. Nationwide survey of Kawasaki disease and acute rheumatic fever. J Pediatr. 1991;119:279–82.

1864


21. Naoe S, Takahashi K, Masuda H, et al. Kawasaki disease. With particular emphasis on arterial lesions. Acta Pathol Jpn. 1991;41:785–97. 22. Newburger JW, Takahashi M, Gerber MA, et al.; Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease; Council on Cardiovascular Disease in the Young; American Heart Association; American Academy of Pediatrics. Diagnosis, treatment, and long-term management of

Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association. Circulation. 2004;110(17):2747–71. 23. Newburger JW, Taubert KA, Shulman ST, et al. Summary and abstracts of the Seventh International Kawasaki Disease Symposium: December 4–7, 2001.

SECTION 7 Miscellaneous and Other Noninvasive Techniques

Chapters Chapter 77 Chapter 78 Chapter 79 Chapter 80 Chapter 81

Echocardiography in Systemic Diseases Echocardiography in Women Echocardiography in the Elderly How to do Echo for the Electrophysiologist Echocardiography in Life-Threatening Conditions

Chapter 82 Lung Ultrasound in Cardiology Chapter 83 The Future of Echocardiography and Ultrasound Chapter 84 A Primer on Cardiac MRI for the Echocardiographer Chapter 85 Cardiac CT Imaging

1867

CHAPTER 77 Echocardiography in Systemic Diseases Mahdi Veillet-Chowdhury, Smadar Kort

Snapshot  Systemic Lupus Erythematosus  Rheumatoid ArthriƟs  Hypereosinophilic Syndrome  Systemic Sclerosis  Renal Disease  Amyloidosis

INTRODUCTION The presence of cardiac involvement in patients who suffer various systemic diseases is relatively common and is often associated with worse prognosis; therefore, early diagnosis is critical. Echocardiography is a simple, noninvasive imaging modality that is valuable in the evaluation of patients with suspected cardiac manifestations of certain disease processes, from autoimmune syndromes to inflammatory conditions to various infections. In this chapter, we will discuss the role of echocardiography in the assessment of these patients and illustrate how newer features of echocardiography such as tissue Doppler imaging, three-dimensional (3D) echocardiography, and speckle-tracking can be used to better assess specific pathologies.

SYSTEMIC LUPUS ERYTHEMATOSUS Systemic lupus erythematosus (SLE) is an autoimmune disorder involving antinuclear autoantibodies that causes a systemic inflammatory state in patients. Cardiovascular involvement is common, which includes accelerated

 Carcinoid  Chagas Disease  Sarcoidosis  Thyroid Disorders  NutriƟonal Deficiency

atherosclerosis, valvular disease, pericardial disease, and myocardial disease.1,2 Echocardiography plays a vital role in the detection of involvement of cardiac structures, such as detection of pericardial effusions or diastolic dysfunction. In fact, the presence of pericarditis is one of the classifying criteria established by the American College of Rheumatology for diagnosing SLE. Studies have shown the prevalence of pericardial effusions in patients with SLE ranging from 20% to 30% in some populations.3,4 The chronic inflammatory state can lead to early atherosclerosis, vasculitis, and ultimately myocardial involvement, leading to left ventricular (LV) diastolic dysfunction. A study of 85 SLE patients described abnormally prolonged isovolumetric relaxation times (IVRTs) and significantly greater thickness of the interventricular septum and posterior wall, indicating worsened diastolic function.5 Another frequent finding in patients with SLE is the detection of Libman–Sacks endocarditis. Libman–Sacks endocarditis is a nonbacterial verrucous valvular lesion that often involves the mitral valve (MV) (Fig. 77.1).6 It is believed that the deposition of fibrin-platelet thrombi on the affected valve leads to the vegetations. As patients

1868

Section 7: Miscellaneous and Other Noninvasive Techniques

Fig. 77.1: Libman–Sacks endocarditis in a 58-year-old woman with systemic lupus erythematosus (SLE). The transesophageal echocardiogram (TEE) demonstrates a verrucous lesion on the anterior mitral valve leaflet (arrow). (LA: Left atrium; LV: Left ventricle).

are usually asymptomatic, Libman–Sacks endocarditis is often identified at autopsy, resulting in underestimation of the true prevalence of this entity by initial studies.7 However, with increased awareness of this lesion and the development of more advanced echocardiographic modalities, a prevalence of up to 43% has been reported.6,8 The vegetations seen on transthoracic echocardiography (TTE) and transesophageal echocardiogram (TEE) are usually irregular in shape, firmly attached to the surface at the valve ring and commissures, and vary in size and echodensity.9–11

RHEUMATOID ARTHRITIS Rheumatoid arthritis (RA) is a systemic autoimmune disease of unknown etiology that can affect several organs, including the heart. Cardiac manifestations include coronary artery disease, conduction disease, valvular heart disease, pericardial disease, and myocardial disease.12 Both systolic and diastolic LV dysfunction can occur due to a combination of accelerated cardiovascular disease, chronic inflammation, and use of cardiotoxic medications causing nodules and fibrosis in the myocardium.13 Since the myocardial performance index (MPI) is independent of heart rate, preload, and afterload, it has been used to assess global LV dysfunction in RA patients. A study involving 40 patients with active RA revealed that the MPI of the LV was significantly higher than those of control patients, indicative of abnormal global LV function, while the right ventricular (RV) MPI was preserved.14 In combination with

the MPI, the transmitral flow propagation velocity was shown to identify diastolic dysfunction in patients with long-standing history of RA.15 In addition, patients with RA have prolonged left and right ventricular deceleration times (DTs) and IVRTs compared to control subjects.16 A study involving 60 patients with long-standing RA demonstrated that the ratio of the early diastolic velocity of the mitral annulus (E') to the late diastolic velocity of the mitral annulus (A'), as well peak A’ and the ratio between the early diastolic filling (E) to E' (E/E') parameters were significantly impaired. Tissue Doppler imaging (TDI) can add incremental value to conventional Doppler echocardiography in RA patients, especially with RV dysfunction, as RV diastolic impairment can be a predictor of subclinical myocardial and pulmonary disease. A study evaluating RV diastolic function in 35 RA patients revealed that the prevalence of RV diastolic abnormalities defined as a ratio of (E) to atrial filling (A) of <1, was higher in RA patients compared to control subjects.17 The most common cardiac structure involved in RA is the pericardium, with evidence of pericarditis reported to be 30–50% in these patients.18 Although <10% of the patients with pericarditis are symptomatic, constrictive pericarditis or rapidly developing exudative effusions portend a poor prognosis.18,19 Valvular disease is also common, with a reported prevalence of approximately 39% in patients with RA.20 The inflammatory state leads to the formation of nodules and fibrosis throughout the entire valvular apparatus, most frequently involving the mitral and aortic valves (Movie clip 77.1; Figs 77.2A to C).20–22 Mitral regurgitation is the most common valvular abnormality, while aortic regurgitation and stenosis can also occur.23

HYPEREOSINOPHILIC SYNDROME Hypereosinophilic syndrome (HES), or Loeffler’s syndrome, is characterized by a persistently elevated eosinophil count (≥1.5 × 109/L) for at least 6 months as well as eosinophil-related end organ damage with no identifiable cause. HES tends to occur more commonly in males between the third and sixth decades of life. Cardiac involvement has been reported in >50% of patients and suggests a poor prognosis.24 Cardiac damage classically occurs in two stages. In the first stage, acute myonecrosis occurs due to eosinophilic infiltration of the myocardium and subsequent release of toxic proteins. The later stage is described by the formation of mural thrombi, endomyocardial fibrosis, valvular disease, and restrictive cardiomyopathy.25,26

Chapter 77: Echocardiography in Systemic Diseases

1869

A

B

C

Figs 77.2A to C: (A) A three-dimensional (3D) echocardiogram of a 56-year-old gentleman with rheumatoid arthritis (RA). A parasternal long-axis view of a thickened and fibrotic mitral valve (MV) leaflets and chordae (arrow); (B) A 3D parasternal short-axis view of the thickened and fibrotic MV (arrow); (C) A two-dimensional (2D) parasternal short-axis view of a thickened aortic valve (AV) with a small nodular density on the left coronary cusp (curved arrow). (LV: Left ventricle).

On echocardiography, there can be evidence of endomyocardial thickening with plaques larger than 2 mm. In addition, valvular regurgitation due to adhesion of the valvular apparatus can become clinically significant. Progressive scarring causes restriction of the chordae tendinae, which often affects the posterior mitral leaflet.27,28 In addition, there can be evidence of fibrothrombotic growth on both the ventricular apices due to blood stasis and denuded myocardium, occasionally causing obliteration of the cavities (Figs 77.3 and 77.4). Studies have also reported a predilection for pericardial involvement, with one study demonstrating pericardial effusions in almost one-third of subjects with HES.25 As mentioned earlier, later stages of HES can cause restrictive cardiomyopathy. As the endomyocardial thickening and fibrosis leads to diastolic dysfunction, Doppler echocardiography and TDI measurements of diastolic parameters can help in evaluating the full scope

of cardiac involvement, such as decreases in transmitral E-wave DT and an E/A ratio consistent with restrictive physiology.

SYSTEMIC SCLEROSIS Systemic sclerosis (SSc) is a connective tissue disorder characterized by vascular lesions and widespread fibrosis of the skin and other organs, frequently the heart, with one study showing the prevalence of cardiac involvement to be as high as 32% in patients with diffuse SSc.29 A range of cardiac manifestations can be seen, including conduction system disease, coronary artery disease, pericardial involvement, RV dysfunction due to pulmonary hypertension, and both LV systolic and diastolic dysfunction. As studies have shown that patients with cardiac involvement confer a poor prognosis, screening for subclinical disease with echocardiography is vital.30

1870


Fig. 77.3: A 74-year-old gentleman with hypereosinophilic syndrome (HES). A two-dimensional (2D) apical four-chamber view demonstrating thickening and infiltration of the right ventricle (RV; arrow). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

B

C

D

Figs 77.4A to D: (A) A 67-year-old gentleman with asthma and hypereosinophilic syndrome (HES) with an eosinophil count of 5.6 × 109/L. A two-dimensional (2D) parasternal long-axis view demonstrating thickening and infiltration of the left ventricle (LV); (B) A parasternal short-axis view demonstrating thickening and infiltration of the LV (arrow); (C) An apical four-chamber view demonstrating thickening and infiltration of the LV (arrow); (D) An apical two-chamber view demonstrating thickening and infiltration of the LV. (LA: Left atrium; LV: Left ventricle; RV: Right ventricle).


Myocardial fibrosis is a hallmark cardiac manifestation of SSc and can lead to increased ventricular mass, ventricular wall motion abnormalities, and impaired diastolic relaxation.31,32 TDI can be used to measure systolic longitudinal velocity (S') and mitral annular velocity (E') to identify patients with systolic and diastolic dysfunction, respectively.33 A study with 100 consecutive patients with SSc showed that using TDI to evaluate mitral and tricuspid annular velocities, the presence of subtle RV and LV dysfunction was able unmasked.34 Speckle-tracking echocardiography can also provide insight toward subclinical LV and RV systolic dysfunction. Another study showed that in SSc subjects with a normal radionuclide ejection fraction, speckle imaging was able to detect lower systolic and diastolic strain rates.35 Speckle-tracking imaging of the RV revealed that while TDI indices were similar in subjects with SSc compared with controls, the SSc subjects were found to have reduced strain.36 Due to pulmonary involvement, the presence of secondary RV dysfunction needs to be fully excluded. Therefore, validated measurements of RV function should be incorporated into the routine assessment in SSc, and should include echocardiographic parameters such as tricuspid annular plane systolic excursion, RV free wall TDI-derived S', and pulmonary artery pressures.37,38 Pericardial disease in SSc can range from asymptomatic pericardial effusions to constrictive pericarditis. Although up to 78% of patients with SSc have been reported to have some pericardial involvement, the prevalence of clinically symptomatic disease is low at 5–16%.39–41 Pericardial effusions in the setting of pulmonary hypertension is a prognostic indicator in patients with SSc, as the presence of pericardial effusions together with increased right atrial (RA) size and abnormal interventricular septal displacement during diastole predicts poor outcomes.42 Valvular disease has also been described, with nodular thickening of the MV reported in up to 38% of patients with SSc.43

RENAL DISEASE Cardiovascular mortality is significantly increased in patients with chronic kidney disease (CKD), leading to earlier atherosclerosis, valvular and pericardial disease, arrhythmias, and heart failure. Use of echocardiography plays a crucial role in the evaluation of these patients as the structural and functional abnormalities can alter the management and prognosis of this patient population. Over time, a combination of CKD and other medical

1871

conditions such as hypertension and diabetes leads to myocardial fibrosis and the development of left ventricular hypertrophy (LVH). However, due to the high tendency for pressure and volume overload to occur, the cardiac structure can display varying types of hypertrophy.44,45 This cardiac alteration leads to dysfunction in both diastolic and systolic properties. Even though LVH is fairly common in this population, the accurate assessment of LV mass index is especially difficult due to variations in patients’ volume status.44,46 Similarly, diastolic assessment in these patients could be challenging. Elevated LV filling pressures signify worsening relaxation and compliance of the LV; however, in the CKD patient, the wide variations in volume status makes mitral inflow velocity measurements challenging.47 Therefore, other assessments can further aid in evaluation of diastolic dysfunction. In hemodialysis (HD) patients, left atrial (LA) enlargement, assessed by calculating the LA volume index, has been found to be a predictor of mortality.48,49 Furthermore, the ratio of early mitral flow velocity to early mitral annulus velocity (E/E') has been proven to be a reliable measure of LV filling pressures in end-stage renal disease (ESRD) patients.50 Uremic cardiomyopathy is characterized by LV enlargement, hypertrophy, and systolic dysfunction. Fractional shortening, a measurement of global LV systolic function in the absence of regional abnormalities, could overestimate contractility in patients with concentric LVH and, therefore, should not be used in these patients. In dialysis patients, tissue velocity and strain imaging can detect changes in LV function and are less affected by the volume status of the patient.51 The utility of stress echocardiography for excluding coronary atherosclerotic disease in these patients is uncertain, given the relatively lower specificity of this modality in the presence of LVH, a common finding in this patient population.52 Another common finding in HD patients is myocardial stunning due to acute myocardial ischemia during dialysis sessions, which over time increases the risk of heart failure and arrhythmias.53 A study examining 70 HD patients found a significant reduction in systolic function in 64% of subjects.54 Given the abnormalities in calcium and phosphorus metabolism and inflammation associated with renal disease, valvular and vascular calcifications are common in patients with CKD, particularly mitral annular calcifications (MACs), which has been reported to occur in > 40% of ESRD patients (Movie clip 77.2; Figs 77.5A and B).55–57 Of great importance are the findings of mobile components associated with MAC, as these lesions can become sources of emboli.58–60

1872


A

B

Figs 77.5A and B: (A) A 59-year-old woman with endstage renal disease (ESRD). A transesophageal echocardiogram (TEE) demonstrating a large echodensity (arrows) on the atrial surface of the posterior mitral valve (MV) annulus and leaflet consistent with mobile mitral annular calcification (MAC); (B) A TEE zoomed in view demonstrating a large echodensity (arrows) on the atrial surface of the posterior MV annulus and leaflet consistent with mobile mitral annular calcification (MAC). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Uremic pericarditis is used to describe ESRD patients who develop clinical manifestations of pericarditis. Studies have reported a wide range of prevalences, but generally occur in < 20% of patients with ESRD.61–63 Similar to the development of pericarditis, pericardial effusions can also develop, with studies showing prevalences of 11–27% in ESRD patients.62,64–68

AMYLOIDOSIS Amyloidosis is a systemic disorder that is caused by extracellular deposits of insoluble aggregated proteins with a β-pleated sheath configuration. The incidence of light chain (AL) amyloidosis or primary amyloidosis is more than 10 per million person-years in the US population and has a predilection for men in the sixth decade of life.69 Amyloid can affect numerous organ systems but infiltration of the heart confers an extremely poor prognosis, as amyloid patients with congestive heart failure (CHF) have a median survival of about 6 months.70 In cardiac amyloidosis, amyloid deposits infiltrate the myocardium with progression to myocyte necrosis and local interstitial fibrosis. As the heart is thickened, diastolic dysfunction progresses, eventually leading to restrictive cardiomyopathy.71 Due to the reduced compliance of the LV, the chamber diameters remain normal, but the free wall and septum thicken.72 While amyloid deposits are rare in the epicardial

vessels, they can involve the intramural vasculature and lead to microvascular ischemia. In addition, although relatively rare, amyloid can accumulate in the pericardium and lead to constrictive physiology.72 As there is no single test with a great sensitivity to diagnose cardiac amyloid, when evaluating a patient with suspected cardiac amyloid it is important to correlate the clinical picture with the diagnostic findings. Echocardiography can be a valuable tool to support establishing the diagnosis. Although not specific, one of the characteristic two-dimensional (2D) echocardiographic features is a granular appearance of the myocardium (Movie clip 77.3; Figs 77.6 to 77.8). The most common finding is thickening of the LV wall in the absence of other contributing factors such as hypertension or aortic stenosis.73 A study showed that the presence of low voltage on the electrocardiogram (ECG) associated with an interventricular septal thickness of >1.98 cm has a sensitivity of 72% and specificity of 91% for the diagnosis of cardiac amyloidosis.74 It has been shown that this finding has a strong inverse relationship with survival in patients with heart failure due to amyloid.75 A recent study examining seven consecutive patients with endomyocardial biopsy-proven cardiac amyloid found that an echocardiographic pattern of preserved motion of the LV apex and hypokinesis of the basal to mid segments was consistently identified in all patients.76 Other striking features include biatrial enlargement and thickened valves.


1873

Fig. 77.6: An 89-year-old woman with systemic amyloidosis. Threedimensional (3D) apical four-chamber view showing right ventricle (RV) infiltration, can be used to differentiate thickening of the free wall from a moderator band (asterisk). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

B

C

Figs 77.7A to C: (A) An 85-year-old gentleman with systemic amyloidosis. A two-dimensional (2D) apical four-chamber view demonstrating a starry-sky speckled appearance and thickening of the left ventricular (LV) myocardium; (B) A pulsed wave Doppler echocardiography of the mitral valve (MV) demonstrating a transmitral E-velocity (arrow): A-velocity (curved arrow) ratio > 2:1 and a short deceleration time, consistent with restrictive physiology; (C) A tissue-Doppler imaging (TDI) echocardiography of the lateral mitral annulus demonstrating a decreased E'-velocity (asterisk), consistent with abnormal diastolic function. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

Early amyloid deposition does impair isovolumetric relaxation leading to mild diastolic dysfunction with reversal of the transmitral E/A velocity ratio initially, but

eventually leading to restrictive cardiomyopathy with E/A ratio > 2:1. TDI can further assist in the diagnosis as it can show decreased mitral annular velocities and

1874


A

B

C

Figs 77.8A to C: (A) An 80-year-old gentleman with systemic amyloidosis and congestive heart failure. A two-dimensional (2D) apical four-chamber view demonstrating thickening of the left ventricular (LV) myocardium; (B) A pulsed wave Doppler echocardiography of the mitral valve (MV) demonstrating a transmitral E-velocity (arrow): A-velocity (curved arrow) ratio > 2:1, consistent with restrictive physiology; (C) A tissue Doppler imaging (TDI) echocardiography of the lateral mitral annulus demonstrating a decreased E'-velocity (asterisk), consistent with abnormal diastolic function. (LV: Left ventricle).

elevated filling pressures. Investigators have shown that the myocardial velocity profiles of the LV septum and posterior wall show a distinctive serrated pattern not present in patients with hypertension or hypertrophic cardiomyopathy.77 Another useful technique that can provide prognostic information is tissue Doppler-based strain and strain rate imaging (SRI), which can allow accurate assessment of regional myocardial deformation with high spatial and temporal resolution.78 Studies have shown that Dopplerderived longitudinal systolic strain averaged for the 16 segments of the LV can differentiate biopsy-proven cardiac amyloid patients from healthy control patients.79,80 A related newer technique is speckle and derived SRI, which was shown to differentiate cardiac amyloidosis and hypertrophic cardiomyopathy from other causes of increased LV wall thickness.81 The authors found that

global myocardial deformation was significantly lower in patients with cardiac amyloid compared to those with LV hypertrophy due to other causes. Other helpful techniques include the use of contrast echocardiography to evaluate for coronary flow reserve and 3D echocardiography to assess for the presence of intraventricular dyssynchrony. Although these findings are not specific, their presence could help support the diagnosis of this rare condition.82,83

CARCINOID Carcinoid tumors are rare neuroendocrine malignancies derived primarily from enterochromaffin cells, with the primary site usually being in the gastrointestinal tract. The usual presentation occurs in the fifth to seventh decade of life with the classic symptom triad of flushing, secretory diarrhea, and bronchospasm.84 Carcinoid heart disease has been reported to be present in up to 50–60% of patients


with carcinoid syndrome, and should therefore be excluded in these patients.85 Cardiac involvement portends a poor prognosis, as one study has shown reduced mean survival in patients with carcinoid heart disease (life expectancy of 1.6 years compared to 4.6 years in those without cardiac manifestations).86 Cardiac involvement occurs through paraneoplastic effects when tumor growth within the liver allows the secretory products, such as serotonin, to reach the right side of the heart without having gone through inactivation in the hepatic or pulmonary circulatory bed. However, left-sided heart disease can also occur, although the incidence is much less due to the low levels of serotonin present after passing through the lung.86 This disease process manifests in plaque-like endocardial deposits of fibrous tissue on the ventricular and arterial aspects of the tricuspid and pulmonic valves (PVs), respectively.87 The clinical symptoms usually encompass that of right-sided heart failure, although conduction disease, coronary vasospasm, constrictive pericarditis, and restrictive cardiomyopathy have all been reported.88–91 The presence of right-sided heart failure is an independent predictor of mortality in this population.92 Echocardiography is a key tool in aiding the diagnosis and management of carcinoid heart disease. Typical features include thickening of the valve leaflets and cusps, causing them to become retracted, fixed, and noncoapting, resulting in tricuspid and pulmonic stenosis and regurgitation (Movie clip 77.4; Figs 77.9 and 77.10).86 Most commonly, thickening involves the septal and anterior leaflets of the tricuspid valve (TV), as well as the chordae and papillary muscles.93 This results in echocardiographic signs of severe tricuspid regurgitation, such as enlarged vena contracta width and regurgitant volume, dilated inferior vena cava (IVC), and systolic flow reversal in the hepatic veins. Typically, continuous wave Doppler echocardiography shows a dagger-shaped profile, with an early peak pressure and rapid decline.86 If the PV is involved, the predominant location of the plaques are at the pulmonic root, causing constriction of the root and orifice.94 However, concomitant pulmonic regurgitation is not uncommon as demonstrated by prior studies.86 If a patent foramen ovale (PFO) is present, the increased RA pressure due to tricuspid and pulmonic valvular disease can result in a significant right-to-left shunt, promoting the likelihood of developing left heart involvement with carcinoid, and therefore the presence of a PFO should routinely be excluded.95

1875

TDI also can play an important role in evaluating the progression of carcinoid heart disease. A study of 41 patients with carcinoid syndrome demonstrated that E/E' ratio ≤ 8 was an independent marker of death.96 Myocardial strain echocardiography can also help in the evaluation of this population. Aside from valvular disease, carcinoid can also lead to the development of mural endocardial fibrosis of the ventricles. A study involving 89 patients with carcinoid disease revealed reduced RV function using strain compared with healthy control subjects. This reduced RV function was independent of valvular involvement, further supporting the role of tissue Doppler when assessing patients with carcinoid.97

CHAGAS DISEASE Chagas disease is a tropical disease endemic in Mexico, Central, and South America caused by the parasite Trypanosoma cruzi. There is usually an acute or early phase and a chronic or late phase. Although infrequent, fulminant myocarditis can occur in 1–5% of patients in the acute phase.98 More commonly, about 30% of seropositive individuals develop cardiomyopathy several years after the acute phase.99 This usually occurs through a combination of cardiac dysautonomia, microvascular disease, parasite, and immune-mediated myocardial injury. A recent systematic review demonstrated that positive serology for Chagas disease is associated with a higher risk of death in patients with heart failure.100 Echocardiography can provide valuable information regarding the extent of myocardial damage and, therefore, help determine the prognosis of patients with Chagas heart disease. Apart from acute myocarditis, the early phase of Chagas disease can lead to the rapid development of pericardial effusions, with one study noting the presence of pericardial effusions in 42% of subjects.101 Most of the structural heart changes take place slowly over years after the initial infection goes unnoticed (Movie clip 77.5; Figs 77.11A to F). Studies have shown that > 50% of patients with Chagas disease develop apical aneurysms, and become at higher risk of forming a mural thrombus.102 Both TTE and TEE were shown to recognize potential cardiac source of emboli with high accuracy.103 More advanced cardiac disease include global cardiac dilatation and diffuse hypokinesis; however, early in the disease process, segmental wall motion abnormalities can also be identified on 2D echocardiograms, with the apical and posteroinferior walls being the most commonly

1876


A

B

C

D

Figs 77.9A to D: A 53-year-old gentleman with metastatic carcinoid disease to bones and liver. A two-dimensional (2D) echocardiography showing a thickened, retracted, and noncoapting tricuspid valve (arrow); (B) A color flow Doppler echocardiography showing severe tricuspid regurgitation with a large regurgitant jet; (C) A continuous wave (CW) Doppler echocardiography showing an increased E-velocity across the tricuspid valve (TV), consistent with severe tricuspid stenosis (curved arrow). However, the mean pressure gradient of 5 mm Hg across the valve excludes the presence of significant stenosis as the etiology; (D) A three-dimensional (3D) short-axis view demonstrating a thickened, fixed, noncoapting tricuspid valve (arrow). (RA: Right atrium; RV: Right ventricle).

affected.104–106 Dobutamine stress echocardiography has a role when evaluating these patients, as a blunted heart and contractile response during dobutamine infusion can be found, even in subjects without baseline regional wall motion abnormalities.107 Interestingly, in this study, few patients demonstrated a biphasic response to dobutamine, with improvement in contractility at a low dose, and deterioration in contractile function at a higher dose. Over time, patients infected with Chagas are at high risk of developing both systolic and diastolic dysfunction. A study of 169 patients with Chagas cardiomyopathy reported that a reduced TDI septal E'-wave of 11 cm/s and a septal E/E' ratio > 7.2 were both highly sensitive and

moderately specific for detection of any stage of diastolic dysfunction.105 In addition, in symptomatic patients, the MPI is markedly higher for both the LV and RV, consistent with combined severe systolic and diastolic myocardial dysfunction.108

SARCOIDOSIS Sarcoidosis is a multisystem disorder that is characterized by the presence of noncaseating granulomas that can affect numerous organs in the body. The etiology remains unknown, although environmental, occupational, infectious, and genetic causes have all been proposed. While


A

1877

B

Figs 77.10A and B: (A) A 53-year-old gentleman with carcinoid heart disease. A two-dimensional (2D) short-axis view showing a thickened and fixed pulmonic valve (PV; arrow); (B) A continuous wave (CW) Doppler echocardiography showing mild pulmonic stenosis with a mean transvalvular pressure gradient of 20 mm Hg (curved arrow).

A

B

C

D

Figs 77.11A to D

1878


E

F

Figs 77.11A to F: A 28-year-old gentleman emigrated from El Salvador and presented with Chagas heart disease. A two-dimensional (2D) parasternal long-axis view showing a dilated left ventricle (LV; asterisk); (B) A 2D echocardiogram short-axis view showing a dilated LV (asterisk); (C) A 2D apical four-chamber view showing a dilated LV with a thinned apex (arrow); (D) A zoomed-in 2D apical fourchamber view showing mitral regurgitation (MR); (E) A 2D apical four-chamber view showing a dilated LV with a thinned apex (arrow); (F) A 2D apical four-chamber view showing a dilated LV with a thinned apex (arrow) (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

it can affect people across all ethnic groups and ages, studies have shown that there is a predilection among African Americans and Northern Europeans.109 While the disease can remain asymptomatic for many years, the most common presentation involves the pulmonary system, causing cough and dyspnea. However, cardiac involvement is not uncommon, with a prevalence in the United States reported to be about 25% in patients with systemic sarcoidosis, and should, therefore, be excluded in these patients.110 All cardiac structures can be involved—infiltration of the granulomas in the conduction system, myocardial involvement of all chambers, and the development of pericardial effusions have all been reported.111 Although considered the gold standard for establishing the diagnoses, endomyocardial biopsy often is unable to demonstrate pathological evidence of cardiac sarcoidosis.112 Therefore, noninvasive modalities, such as echocardiography, are a valuable tool in the diagnoses and management of sarcoid heart disease, as it can demonstrate a range of structural abnormalities, and can be repeated as needed (Movie clips 77.6 to 77.8; Figs 77.12 and 77.13). Given that pulmonary disease is the most common manifestation of sarcoidosis, right-sided heart failure due to pulmonary hypertension is commonly observed; therefore, evidence of elevated RV pressures should be

evaluated using echocardiography.112 The LV free wall and interventricular septum are the most commonly affected sites.111 LV dilatation and wall thinning can occur leading to aneurysm formation.113 Granuloma penetration into the myocardium can cause myocardial fibrosis and lead to systolic and diastolic dysfunction with wall motion abnormalities, usually at the mid and basal levels.114 In addition, both thickening and thinning of the interventricular septum with dyskinetic segments as well as papillary muscle dysfunction leading to valvular insufficiency have also been reported.114,115 It is important to identify these echocardiographic abnormalities as studies have shown that the severity of LV dysfunction and end-diastolic diameter are independent predictors of mortality in this patient population.116 Other echocardiographic abnormalities have been noted in patients with sarcoidosis. Pericardial effusions have been reported in up to 19% of patients with cardiac sarcoidosis.117 In addition, constrictive pericarditis has been reported, although this is infrequent.118 One study looking at 69 patients with chronic sarcoidosis found that patients with sarcoid had lower midwall fractional shortening compared with controls.119 Furthermore, echocardiography can be used to detect cyclic variation of integrated backscatter to estimate the myocardial acoustic properties to recognize cardiac sarcoidosis.120


Fig. 77.12: A 41-year-old gentleman with sarcoidosis and severe segmental left ventricular (LV) systolic dysfunction, who had normal coronary arteries on cardiac catheterization. A two-dimensional (2D) parasternal short-axis view showing a dilated LV. (LV: Left ventricle).

THYROID DISORDERS Hyperthyroidism is characterized by elevated peripheral free thyroid hormone levels combined with decreased thyroid stimulating hormone (TSH) levels. Thyrotoxicosis can lead to significant changes in the cardiac structure and function, causing hypertension, heart failure, and arrhythmias. Echocardiography can play an important role in the evaluation of patients with thyroid disorders, as even subclinical hyperthyroidism can lead to cardiac abnormalities. Elevated thyroid hormones leads to a high cardiac output by up to 50–300% as well as increased preload, leading to an increase in LV mass and LA size.121–124 Due to the increased cardiac contractility and heart rate, shortened interventricular conduction time and pre-ejection period have been demonstrated.123 SRI has shown enhancement of systolic stain rate in patients with subclinical hyperthyroidism due to the greater early systolic phase deformation.125 However, stress echocardiography has demonstrated a blunted increase in LV ejection fraction and cardiac output.126 In regards to RV function, TDI has demonstrated enhanced systolic function in subjects with overt hyperthyroidism.127 Mild diastolic dysfunction has also been demonstrated by Doppler echocardiography, with reduced peak E-wave velocity and a significantly higher peak A-wave velocity.125 TDI reveals impairment of the mitral annular velocity and

1879

Fig. 77.13: A 74-year-old woman with sarcoidosis. A twodimensional (2D) apical four-chamber view demonstrates right ventricular (RV) hypertrophy, mildly dilated RV, and right atrium (RA). LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle.

SRI reveals a significant decrease in diastolic function. In patients with Graves’ disease, valvular abnormalities have been reported, such as tricuspid regurgitation and MV prolapse.128 In contrast to hyperthyroidism, hypothyroid is characterized by decreased lower peripheral thyroid hormone levels and elevated TSH levels. Physiologically, there is evidence of decreased cardiac output and contractility. As compared to hyperthyroidism, there is a predilection for arrhythmias due to prolonged QT interval and the prevalence of heart failure is much less. Again, echocardiographic data plays an important role in the evaluation of these patients. Numerous studies have shown abnormalities in systolic function indices, such as reduced ejection fraction and fractional shortening, and increased pre-ejection period (Movie clip 77.6; Figs 77.14A and B).129–132 In patients with subclinical hypothyroidism, TDI was shown to be able to demonstrate systolic dysfunction during exercise.133,134 LV diastolic dysfunction can easily be diagnosed on echocardiograms by demonstrating the presence of significant impairment of LV filling, prolonged IVRT, and prolongation of the MPI.135–138 Although cardiac tamponade physiology is rare, pericardial effusions can also be found frequently, with studies showing a prevalence of up to 25% in patients with overt hypothyroidism.139

1880


A

B

Figs 77.14A and B: (A) A 59-year-old gentleman with hypothyroidism. A two-dimensional (2D) parasternal long-axis view demonstrating a dilated left ventricle (LV); (B) An apical four-chamber view demonstrating dilated atria and LV. (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A

B

Figs 77.15A and B: (A) A 46-year-old gentleman with a history of alcohol abuse and thiamine deficiency. A two-dimensional (2D) apical two-chamber view showing a dilated left ventricle (LV) with reduced systolic function; (B) A 2D apical two-chamber view showing small LV diameter and significantly improved systolic function after thiamine replacement. (LA: Left atrium; LV: Left ventricle).

NUTRITIONAL DEFICIENCY Nutritional deficiencies in patients can adversely affect myocardial performance and increase cardiovascular morbidity and mortality, particularly thiamine deficiency due to either dietary factors or alcohol abuse (or sometimes a combination of both). Thiamine, or Vitamin B1, is a watersoluble B complex vitamin, and its deficiency has been shown to cause heart disease, most notably beriberi heart disease. Beriberi is characterized by heart failure with biventricular dysfunction with significant hemodynamic abnormalities, most particularly RV failure and elevated LV end-diastolic pressures.140 Echocardiographic features include biventricular enlargement and decreased systolic function of both chambers (Figs 77.15A and B).

REFERENCES 1. Doria A, Iaccarino L, Sarzi-Puttini P, et al. Cardiac involvement in systemic lupus erythematosus. Lupus. 2005;14(9):683–6. 2. Colombo BM, Cacciapaglia F, Puntoni M, et al. Traditional and non traditional risk factors in accelerated atherosclerosis in systemic lupus erythematosus: role of vascular endothelial growth factor (VEGATS Study). Autoimmun Rev. 2009;8(4):309–15. 3. Klinkhoff AV, Thompson CR, Reid GD, et al. M-mode and two-dimensional echocardiographic abnormalities in systemic lupus erythematosus. JAMA. 1985;253(22): 3273–7. 4. Cervera R, Font J, Paré C, et al. Cardiac disease in systemic lupus erythematosus: prospective study of 70 patients. Ann Rheum Dis. 1992;51(2):156–9.


5. Yu XH, Li YN. Echocardiographic abnormalities in a cohort of Chinese patients with systemic lupus erythematosus: a retrospective analysis of eighty-five cases. J Clin Ultrasound. 2011;39(9):519–26. 6. Roldan CA, Shively BK, Crawford MH. An echocardiographic study of valvular heart disease associated with systemic lupus erythematosus. N Engl J Med. 1996;335(19):1424–30. 7. Galve E, Candell-Riera J, Pigrau C, et al. Prevalence, morphologic types, and evolution of cardiac valvular disease in systemic lupus erythematosus. N Engl J Med. 1988;319(13):817–23. 8. Roldan CA, Qualls CR, Sopko KS, et al. Transthoracic versus transesophageal echocardiography for detection of Libman-Sacks endocarditis: a randomized controlled study. J Rheumatol. 2008;35(2):224–9. 9. Hojnik M, George J, Ziporen L, et al. Heart valve involvement (Libman-Sacks endocarditis) in the antiphospholipid syndrome. Circulation. 1996;93(8):1579–87. 10. Moyssakis I, Tektonidou MG, Vasilliou VA, et al. LibmanSacks endocarditis in systemic lupus erythematosus: prevalence, associations, and evolution. Am J Med. 2007;120(7):636–42. 11. Doherty NE, Siegel RJ. Cardiovascular manifestations of systemic lupus erythematosus. Am Heart J. 1985;110(6): 1257–65. 12. Solomon DH, Karlson EW, Rimm EB, et al. Cardiovascular morbidity and mortality in women diagnosed with rheumatoid arthritis. Circulation. 2003;107(9):1303–7. 13. Ferraccioli G, Tolusso B. Infections, B cell receptor activation and autoimmunity: different check-point impairments lead to autoimmunity, clonal B cell expansion and fibrosis in different immunological settings. Autoimmun Rev. 2007;7(2):109–13. 14. Levendoglu F, Temizhan A, Ugurlu H, et al. Ventricular function abnormalities in active rheumatoid arthritis: a Doppler echocardiographic study. Rheumatol Int. 2004; 24(3):141–6. 15. Alpaslan M, Onrat E, Evcik D. Doppler echocardiographic evaluation of ventricular function in patients with rheumatoid arthritis. Clin Rheumatol. 2003;22(2):84–8. 16. Birdane A, Korkmaz C, Ata N, et al. Tissue Doppler imaging in the evaluation of the left and right ventricular diastolic functions in rheumatoid arthritis. Echocardiography. 2007;24(5):485–93. 17. Seyfeli E, Guler H, Akoglu S, et al. Right ventricular diastolic abnormalities in rheumatoid arthritis and its relationship with left ventricular and pulmonary involvement. A tissue Doppler echocardiographic study. Int J Cardiovasc Imaging. 2006;22(6):745–54. 18. Gordon DA, Stein JL, Broder I. The extra-articular features of rheumatoid arthritis. A systematic analysis of 127 cases. Am J Med. 1973;54(4):445–52. 19. Mitchell DM, Spitz PW, Young DY, et al. Survival, prognosis, and causes of death in rheumatoid arthritis. Arthritis Rheum. 1986;29(6):706–14. 20. Wislowska M, Sypula S, Kowalik I. Echocardiographic findings, 24-hour electrocardiographic Holter monitoring

21.

22.

23.

24.

25.

26.

27. 28.

29.

30.

31.

32.

33.

34.

1881

in patients with rheumatoid arthritis according to Steinbrocker’s criteria, functional index, value of Waaler-Rose titre and duration of disease. Clin Rheumatol. 1998; 17(5): 369–77. Shimaya K, Kurihashi A, Masago R, et al. Rheumatoid arthritis and simultaneous aortic, mitral, and tricuspid valve incompetence. Int J Cardiol. 1999;71(2):181–3. Corrao S, Sallì L, Arnone S, et al. Cardiac involvement in rheumatoid arthritis: evidence of silent heart disease. Eur Heart J. 1995;16(2):253–6. Guedes C, Bianchi-Fior P, Cormier B, et al. Cardiac manifestations of rheumatoid arthritis: a case-control transesophageal echocardiography study in 30 patients. Arthritis Rheum. 2001;45(2):129–35. Klion AD, Bochner BS, Gleich GJ, et al. Approaches to the treatment of hypereosinophilic syndromes: a workshop summary report. J Allergy Clin Immunol. 2006;117(6): 1292–302. Young JD, Peterson CG, Venge P, et al. Mechanism of membrane damage mediated by human eosinophil cationic protein. Nature. 1986;321(6070):613–16. Ogbogu PU, Rosing DR, Horne MK 3rd. Cardiovascular manifestations of hypereosinophilic syndromes. Immunol Allergy Clin North Am. 2007;27(3):457–75. Weller PF, Bubley GJ. The idiopathic hypereosinophilic syndrome. Blood. 1994;83(10):2759–79. Campos O, Fischer CH, Moisés VA, et al. Rupture of chordae tendinae complicating mitral regurgitation in left-sided endomyocardial fibrosis: diagnosis by transesophageal echocardiography. Echocardiography. 2004;21(3):289–90. Ferri C, Valentini G, Cozzi F, et al.; Systemic Sclerosis Study Group of the Italian Society of Rheumatology (SIR-GSSSc). Systemic sclerosis: demographic, clinical, and serologic features and survival in 1,012 Italian patients. Medicine (Baltimore). 2002;81(2):139–53. Clements PJ, Lachenbruch PA, Furst DE, et al. A semiquantitative measure of cardiac involvement that improves prediction of prognosis in systemic sclerosis. Arthritis Rheum. 1991;34(11):1371–80. Hegedüs I, Czirják L. Left ventricular wall motion abnormalities in 80 patients with systemic sclerosis. Clin Rheumatol. 1995;14(2):161–4. Valentini G, Vitale DF, Giunta A, et al. Diastolic abnormalities in systemic sclerosis: evidence for associated defective cardiac functional reserve. Ann Rheum Dis. 1996; 55(7):455–60. Dimitroulas T, Giannakoulas G, Papadopoulou K, et al. Early detection of cardiac involvement in systemic sclerosis assessed by tissue-Doppler echocardiography: relationship with neurohormonal activation and endothelial dysfunction. J Rheumatol. 2010;37(5):993–9. Meune C, Avouac J, Wahbi K, et al. Cardiac involvement in systemic sclerosis assessed by tissue-doppler echocardiography during routine care: A controlled study of 100 consecutive patients. Arthritis Rheum. 2008;58(6):1803–9.

1882


35. Meune C, Allanore Y, Pascal O, et al. Myocardial contractility is early affected in systemic sclerosis: a tissue Doppler echocardiography study. Eur J Echocardiogr. 2005; 6(5):351–7. 36. Matias C, Isla LP, Vasconcelos M, et al. Speckle-trackingderived strain and strain-rate analysis: a technique for the evaluation of early alterations in right ventricle systolic function in patients with systemic sclerosis and normal pulmonary artery pressure. J Cardiovasc Med (Hagerstown). 2009;10(2):129–34. 37. Lindqvist P, Caidahl K, Neuman-Andersen G, et al. Disturbed right ventricular diastolic function in patients with systemic sclerosis: a Doppler tissue imaging study. Chest. 2005;128(2):755–63. 38. Lee CY, Chang SM, Hsiao SH, et al. Right heart function and scleroderma: insights from tricuspid annular plane systolic excursion. Echocardiography. 2007;24(2):118–25. 39. Champion HC. The heart in scleroderma. Rheum Dis Clin North Am. 2008;34(1):181–90; viii. 40. Hachulla AL, Launay D, Gaxotte V, et al. Cardiac magnetic resonance imaging in systemic sclerosis: a cross-sectional observational study of 52 patients. Ann Rheum Dis. 2009;68(12):1878–84. 41. Byers RJ, Marshall DA, Freemont AJ. Pericardial involvement in systemic sclerosis. Ann Rheum Dis. 1997;56(6):393–4. 42. Raymond RJ, Hinderliter AL, Willis PW, et al. Echocardiographic predictors of adverse outcomes in primary pulmonary hypertension. J Am Coll Cardiol. 2002; 39(7):1214–19. 43. D’Angelo WA, Fries JF, Masi AT, et al. Pathologic observations in systemic sclerosis (scleroderma). A study of fifty-eight autopsy cases and fifty-eight matched controls. Am J Med. 1969;46(3):428–40. 44. Foley RN, Curtis BM, Randell EW, et al. Left ventricular hypertrophy in new hemodialysis patients without symptomatic cardiac disease. Clin J Am Soc Nephrol. 2010; (5):805–13. 45. Nardi E, Palermo A, Mulè G, et al. Left ventricular hypertrophy and geometry in hypertensive patients with chronic kidney disease. J Hypertens. 2009;27(3):633–41. 46. McIntyre CW, Odudu A, Eldehni MT. Cardiac assessment in chronic kidney disease. Curr Opin Nephrol Hypertens. 2009;18(6):501–6. 47. Barberato SH, Pecoits Filho R. [Influence of preload reduction on Tei index and other Doppler echocardiographic parameters of left ventricular function]. Arq Bras Cardiol. 2006;86(6):425–31. 48. Barberato SH, Pecoits Filho R. Prognostic value of left atrial volume index in hemodialysis patients. Arq Bras Cardiol. 2007;88(6):643–50. 49. Tripepi G, Benedetto FA, Mallamaci F, et al. Left atrial volume monitoring and cardiovascular risk in patients with end-stage renal disease: a prospective cohort study. J Am Soc Nephrol. 2007;18(4):1316–22. 50. Sharma R, Pellerin D, Gaze DC, et al. Mitral peak Doppler E-wave to peak mitral annulus velocity ratio is an accurate estimate of left ventricular filling pressure and predicts mortality in end-stage renal disease. J Am Soc Echocardiogr. 2006;19(3):266–73.

51. Skulstad H, Urheim S, Edvardsen T, et al. Grading of myocardial dysfunction by tissue Doppler echocardiography: a comparison between velocity, displacement, and strain imaging in acute ischemia. J Am Coll Cardiol. 2006;47(8):1672–82. 52. Bangalore S, Yao SS, Chaudhry FA. Usefulness of stress echocardiography for risk stratification and prognosis of patients with left ventricular hypertrophy. Am J Cardiol. 2007;100(3):536–43. 53. Burton JO, Jefferies HJ, Selby NM, et al. Hemodialysisinduced repetitive myocardial injury results in global and segmental reduction in systolic cardiac function. Clin J Am Soc Nephrol. 2009;4(12):1925–31. 54. Burton JO, Jefferies HJ, Selby NM, et al. Hemodialysisinduced cardiac injury: determinants and associated outcomes. Clin J Am Soc Nephrol. 2009;4(5):914–20. 55. Ribeiro S, Ramos A, Brandão A, et al. Cardiac valve calcification in haemodialysis patients: role of calciumphosphate metabolism. Nephrol Dial Transplant. 1998; 13(8):2037–40. 56. Depace NL, Rohrer AH, Kotler MN, et al. Rapidly progressing, massive mitral annular calcification. Occurrence in a patient with chronic renal failure. Arch Intern Med. 1981;141(12):1663–5. 57. Raggi P, Boulay A, Chasan-Taber S, et al. Cardiac calcification in adult hemodialysis patients. A link between endstage renal disease and cardiovascular disease? J Am Coll Cardiol. 2002;39(4):695–701. 58. Stone E, Cohn D, Deal C, et al. Calcific atrial mass in end-stage renal failure. Nephrol Dial Transplant. 1997; 12(4):807–10. 59. Tsuchihashi K, Nozawa A, Marusaki S, et al. Mobile intracardiac calcinosis: a new risk of thromboembolism in patients with haemodialysed end stage renal disease. Heart. 1999;82(5):638–40. 60. Madu EC, D’Cruz IA, Wall B, et al. Transesophageal echocardiographic spectrum of calcific mitral abnormalities in patients with end-stage renal disease. Echocardiography. 2000;17(1):29–35. 61. Rostand SG, Rutsky EA. Pericarditis in end-stage renal disease. Cardiol Clin. 1990;8(4):701–7. 62. Renfrew R, Buselmeier TJ, Kjellstrand CM. Pericarditis and renal failure. Annu Rev Med. 1980;31:345–60. 63. Beaudry C, Nakamoto S, Kolff WJ. Uremic pericarditis and cardiac tamponade in chronic renal failure. Ann Intern Med. 1966;64(5):990–5. 64. Horton JD, Gelfand MC, Sherber HS. Natural history of asymptomatic pericardial effusions in patients on maintenance hemodialysis. Proc Clin Dial Transplant Forum. 1977;7:76–81. 65. Frommer JP, Young JB, Ayus JC. Asymptomatic pericardial effusion in uremic patients: effect of long-term dialysis. Nephron. 1985;39(4):296–301. 66. Goldstein DH, Nagar C, Srivastava N, et al. Clinically silent pericardial effusions in patients on long-term hemodialysis. Pericardial effusions in hemodialysis. Chest. 1977; 72(6):744–7.


67. Yoshida K, Shiina A, Asano Y, et al. Uremic pericardial effusion: detection and evaluation of uremic pericardial effusion by echocardiography. Clin Nephrol. 1980; 13(6):260–8. 68. Peraino RA. Pericardial effusion in patients treated with maintenance dialysis. Am J Nephrol. 1983;3(6):319–22. 69. Kyle RA, Linos A, Beard CM, et al. Incidence and natural history of primary systemic amyloidosis in Olmsted County, Minnesota, 1950 through 1989. Blood. 1992;79(7):1817–22. 70. Dubrey SW, Cha K, Anderson J, et al. The clinical features of immunoglobulin light-chain (AL) amyloidosis with heart involvement. QJM. 1998;91(2):141–57. 71. Swanton RH, Brooksby IA, Davies MJ, et al. Systolic and diastolic ventricular function in cardiac amyloidosis. Studies in six cases diagnosed with endomyocardial biopsy. Am J Cardiol. 1977;39(5):658–64. 72. Smith TJ, Kyle RA, Lie JT. Clinical significance of histopathologic patterns of cardiac amyloidosis. Mayo Clin Proc. 1984;59(8):547–55. 73. Hamer JP, Janssen S, van Rijswijk MH, et al. Amyloid cardiomyopathy in systemic non-hereditary amyloidosis. Clinical, echocardiographic and electrocardiographic findings in 30 patients with AA and 24 patients with AL amyloidosis. Eur Heart J. 1992;13(5):623–7. 74. Rahman JE, Helou EF, Gelzer-Bell R, et al. Noninvasive diagnosis of biopsy-proven cardiac amyloidosis. J Am Coll Cardiol. 2004;43(3):410–15. 75. Cueto-Garcia L, Reeder GS, Kyle RA, et al. Echocardiographic findings in systemic amyloidosis: spectrum of cardiac involvement and relation to survival. J Am Coll Cardiol. 1985;6(4):737–43. 76. Belkin RN, Kupersmith AC, Khalique O, et al. A novel twodimensional echocardiographic finding in cardiac amyloidosis. Echocardiography. 2010;27(10):1171–6. 77. Oki T, Tanaka H, Yamada H, et al. Diagnosis of cardiac amyloidosis based on the myocardial velocity profile in the hypertrophied left ventricular wall. Am J Cardiol. 2004; 93(7):864–9. 78. Koyama J, Ray-Sequin PA, Davidoff R, et al. Usefulness of pulsed tissue Doppler imaging for evaluating systolic and diastolic left ventricular function in patients with AL (primary) amyloidosis. Am J Cardiol. 2002;89(9):1067–71. 79. Bellavia D, Abraham TP, Pellikka PA, et al. Detection of left ventricular systolic dysfunction in cardiac amyloidosis with strain rate echocardiography. J Am Soc Echocardiogr. 2007;20(10):1194–202. 80. Lindqvist P, Olofsson BO, Backman C, et al. Pulsed tissue Doppler and strain imaging discloses early signs of infiltrative cardiac disease: a study on patients with familial amyloidotic polyneuropathy. Eur J Echocardiogr. 2006;7(1):22–30. 81. Sun JP, Stewart WJ, Yang XS, et al. Differentiation of hypertrophic cardiomyopathy and cardiac amyloidosis from other causes of ventricular wall thickening by two-dimensional strain imaging echocardiography. Am J Cardiol. 2009;103(3):411–15.

1883

82. Abdelmoneim SS, Bernier M, Bellavia D, et al. Myocardial contrast echocardiography in biopsy-proven primary cardiac amyloidosis. Eur J Echocardiogr. 2008;9(2):338–41. 83. Migrino RQ, Harmann L, Woods T, et al. Intraventricular dyssynchrony in light chain amyloidosis: a new mechanism of systolic dysfunction assessed by 3-dimensional echocardiography. Cardiovasc Ultrasound. 2008;6:40. 84. Kulke MH, Mayer RJ. Carcinoid tumors. N Engl J Med. 1999;340(11):858–68. 85. Anderson AS, Krauss D, Lang R. Cardiovascular complications of malignant carcinoid disease. Am Heart J. 1997; 134(4):693–702. 86. Pellikka PA, Tajik AJ, Khandheria BK, et al. Carcinoid heart disease. Clinical and echocardiographic spectrum in 74 patients. Circulation. 1993;87(4):1188–96. 87. Roberts WC, Sjoerdsma A. The cardiac disease associated with the carcinoid syndrome (carcinoid heart disease). Am J Med. 1964;36:5–34. 88. Shehata BM, Thomas JE, Doudenko-Rufforny I. Metastatic carcinoid to the conducting system-is it a rare or merely unrecognized manifestation of carcinoid cardiopathy? Arch Pathol Lab Med. 2002;126(12):1538–40. 89. Topol EJ, Fortuin NJ. Coronary artery spasm and cardiac arrest in carcinoid heart disease. Am J Med. 1984;77(5): 950–2. 90. Goddard MJ, Atkinson C. Cardiac metastasis from a bronchial carcinoid: report of a case presenting with diffuse thickening of the left ventricular wall. J Clin Pathol. 2004;57(7):778–9. 91. Johnston SD, Johnston PW, O’Rourke D. Carcinoid constrictive pericarditis. Heart. 1999;82(5):641–3. 92. Møller JE, Pellikka PA, Bernheim AM, et al. Prognosis of carcinoid heart disease: analysis of 200 cases over two decades. Circulation. 2005; 112(21):3320–7. 93. Bernheim AM, Connolly HM, Hobday TJ, et al. Carcinoid heart disease. Prog Cardiovasc Dis. 2007; 49(6):439–51. 94. Ross EM, Roberts WC. The carcinoid syndrome: comparison of 21 necropsy subjects with carcinoid heart disease to 15 necropsy subjects without carcinoid heart disease. Am J Med. 1985;79(3):339–54. 95. Mansencal N, Mitry E, Forissier JF, et al. Assessment of patent foramen ovale in carcinoid heart disease. Am Heart J. 2006;151(5):1129.e1–6. 96. Mansencal N, McKenna WJ, Mitry E, et al. Comparison of prognostic value of tissue Doppler imaging in carcinoid heart disease versus the value in patients with the carcinoid syndrome but without carcinoid heart disease. Am J Cardiol. 2010;105(4):527–31. 97. Haugaa KH, Bergestuen DS, Sahakyan LG, et al. Evaluation of right ventricular dysfunction by myocardial strain echocardiography in patients with intestinal carcinoid disease. J Am Soc Echocardiogr. 2011;24(6):644–50. 98. Rosenbaum MB. Chagasic myocardiopathy. Prog Cardiovasc Dis. 1964;7:199–225. 99. Dias E, Laranja FS, Miranda A, et al. Chagas’ disease; a clinical, epidemiologic, and pathologic study. Circulation. 1956;14(6):1035–60.

1884


100. Linetzky B, Konfino J, Castellana N, et al. Risk of cardiovascular events associated with positive serology for Chagas: a systematic review. Int J Epidemiol. 2012; 41(5): 1356–66. 101. Parada H, Carrasco HA, Añez N, et al. Cardiac involvement is a constant finding in acute Chagas’ disease: a clinical, parasitological and histopathological study. Int J Cardiol. 1997;60(1):49–54. 102. Acquatella H. Echocardiography in Chagas heart disease. Circulation. 2007;115(9):1124–31. 103. Nunes Mdo C, Barbosa MM, Rocha MO. Peculiar aspects of cardiogenic embolism in patients with Chagas’ cardiomyopathy: a transthoracic and transesophageal echocardiographic study. J Am Soc Echocardiogr. 2005; 18(7):761–7. 104. Barros MV, Ribeiro AL, Machado FS, et al. Doppler tissue imaging to assess systolic function in Chagas’ disease. Arq Bras Cardiol. 2003 Jan;80(1):36–40, 31–5. 105. Migliore RA, Adaniya ME, Tamagusuku H, et al. Assessment of diastolic function in Chagas’ disease with pulsed doppler tissue imaging]. Arch Cardiol Mex. 2004;74(1):31–8. 106. Vinicius Lins Barros M, Otávio Da Costa Rocha M, Luiz Pinho Ribeiro A, et al. Tissue Doppler imaging in the evaluation of the regional diastolic function in chagas’ disease. Eur J Echocardiogr. 2001;2(2):94–9. 107. Acquatella H, Pérez JE, Condado JA, et al. Limited myocardial contractile reserve and chronotropic incompetence in patients with chronic Chagas’ disease: assessment by dobutamine stress echocardiography. J Am Coll Cardiol. 1999;33(2):522–9. 108. Yacoub S, Birks EJ, Slavik Z, et al. Early detection of myocardial dysfunction in Chagas disease using novel echocardiographic indices. Trans R Soc Trop Med Hyg. 2003;97(5):528–34. 109. Rossman MD, Kreider ME. Lesson learned from ACCESS (A Case Controlled Etiologic Study of Sarcoidosis). Proc Am Thorac Soc. 2007;4(5):453–6. 110. Silverman KJ, Hutchins GM, Bulkley BH. Cardiac sarcoid: a clinicopathologic study of 84 unselected patients with systemic sarcoidosis. Circulation. 1978;58(6):1204–11. 111. Roberts WC, McAllister HA Jr, Ferrans VJ. Sarcoidosis of the heart. A clinicopathologic study of 35 necropsy patients (group 1) and review of 78 previously described necropsy patients (group 11). Am J Med. 1977;63(1):86–108. 112. Dubrey SW, Bell A, Mittal TK. Sarcoid heart disease. Postgrad Med J. 2007;83(984):618–23. 113. Ayyala US, Nair AP, Padilla ML. Cardiac sarcoidosis. Clin Chest Med. 2008;29(3):493–508, ix. 114. Burstow DJ, Tajik AJ, Bailey KR, et al. Two-dimensional echocardiographic findings in systemic sarcoidosis. Am J Cardiol. 1989;63(7):478–82. 115. Lewin RF, Mor R, Spitzer S, et al. Echocardiographic evaluation of patients with systemic sarcoidosis. Am Heart J. k1985;110(1 Pt 1):116–22. 116. Yazaki Y, Isobe M, Hiroe M, et al. Central Japan Heart Study Group. Prognostic determinants of long-term survival in

117. 118. 119.

120.

121.

122.

123.

124.

125.

126.

127.

128.

129.

130.

131.

132.

Japanese patients with cardiac sarcoidosis treated with prednisone. Am J Cardiol. 2001;88(9):1006–10. Kinney E, Murthy R, Ascunce G, et al. Pericardial effusions in sarcoidosis. Chest. 1979;76(4):476–8. Garrett J, O’Neill H, Blake S. Constrictive pericarditis associated with sarcoidosis. Am Heart J. 1984;107(2):394. Focardi M, Picchi A, Nikiforakis N, et al. Assessment of cardiac involvement in sarcoidosis by echocardiography. Rheumatol Int. 2009;29(9):1051–5. Yasutake H, Seino Y, Kashiwagi M, et al. Detection of cardiac sarcoidosis using cardiac markers and myocardial integrated backscatter. Int J Cardiol. 2005;102(2):259–68. Biondi B, Kahaly GJ. Cardiovascular involvement in patients with different causes of hyperthyroidism. Nat Rev Endocrinol. 2010;6(8):431–43. Sgarbi JA, Villaça FG, Garbeline B, et al. The effects of early antithyroid therapy for endogenous subclinical hyperthyroidism in clinical and heart abnormalities. J Clin Endocrinol Metab. 2003;88(4):1672–7. Biondi B, Palmieri EA, Lombardi G, et al. Effects of thyroid hormone on cardiac function: the relative importance of heart rate, loading conditions, and myocardial contractility in the regulation of cardiac performance in human hyperthyroidism. J Clin Endocrinol Metab. 2002;87(3): 968–74. Smit JW, Eustatia-Rutten CF, Corssmit EP, et al. Reversible diastolic dysfunction after long-term exogenous subclinical hyperthyroidism: a randomized, placebo-controlled study. J Clin Endocrinol Metab. 2005;90(11):6041–7. Di Bello V, Aghini-Lombardi F, Monzani F, et al. Early abnormalities of left ventricular myocardial characteristics associated with subclinical hyperthyroidism. J Endocrinol Invest. 2007;30(7):564–71. Kahaly GJ, Wagner S, Nieswandt J, et al. Stress echocardiography in hyperthyroidism. J Clin Endocrinol Metab. 1999;84(7):2308–13. Arinc H, Gunduz H, Tamer A, et al. Evaluation of right ventricular function in patients with thyroid dysfunction. Cardiology. 2006;105(2):89–94. Kage K, Kira Y, Sekine I, et al. High incidence of mitral and tricuspid regurgitation in patients with Graves’ disease detected by two-dimensional color Doppler echocardiography. Intern Med. 1993;32(5):374–6. Crowley WF Jr, Ridgway EC, Bough EW, et al. Noninvasive evaluation of cardiac function in hypothyroidism. Response to gradual thyroxine replacement. N Engl J Med. 1977;296(1):1–6. Forfar JC, Muir AL, Toft AD. Left ventricular function in hypothyroidism. Responses to exercise and beta adrenoceptor blockade. Br Heart J. 1982;48(3):278–84. Lee RT, Plappert M, Sutton MG. Depressed left ventricular systolic ejection force in hypothyroidism. Am J Cardiol. 1990;65(7):526–7. Vitale G, Galderisi M, Lupoli GA, et al. Left ventricular myocardial impairment in subclinical hypothyroidism assessed by a new ultrasound tool: pulsed tissue Doppler. J Clin Endocrinol Metab. 2002;87(9):4350–5.


133. Arinc H, Gunduz H, Tamer A, et al. Tissue Doppler echocardiography in evaluation of cardiac effects of subclinical hypothyroidism. Int J Cardiovasc Imaging. 2006;22(2): 177–86. 134. Kosar F, Sahin I, Turan N, et al. Evaluation of right and left ventricular function using pulsed-wave tissue Doppler echocardiography in patients with subclinical hypothyroidism. J Endocrinol Invest. 2005;28(8):704–10. 135. Doin FL, Borges Mda R, Campos O, et al. Effect of central hypothyroidism on Doppler-derived myocardial performance index. J Am Soc Echocardiogr. 2004;17(6):622–9. 136. Biondi B, Klein I. Hypothyroidism as a risk factor for cardiovascular disease. Endocrine. 2004;24(1):1–13.

1885

137. Földes J, Istvánfy M, Halmágyi M, et al. Hypothyroidism and the heart. Examination of left ventricular function in subclinical hypothyroidism. Acta Med Hung. 1987; 44(4): 337–47. 138. Aghini-Lombardi F, Fabrizio AL, Di Bello V, et al. Early textural and functional alterations of left ventricular myocardium in mild hypothyroidism. Eur J Endocrinol. 2006;155(1):3–9. 139. Kahaly GJ, Dillmann WH. Thyroid hormone action in the heart. Endocr Rev. 2005;26(5):704–28. 140. Ayzenberg O, Silber MH, Bortz D. Beriberi heart disease. A case report describing the haemodynamic features. S Afr Med J. 1985;68(4):263–5.

CHAPTER 78 Echocardiography in Women Jennifer Kiessling, Navin C Nanda, Tugba Kemaloglu Öz, Aylin Sungur, Kunal Bhagatwala, Nidhi M Karia

Snapshot  Differences in Echocardiographic Measurements and

Technical Considera ons  Structural Heart Disease: MVP, Mitral Stenosis, and Mitral Annular Calcifica on  Ischemic Heart Disease/Stress Echocardiography/Polycys c Ovarian Syndrome

INTRODUCTION In terms of cardiac disease, it is often thought that men are more affected, while women are somehow protected. This has proven to be untrue. This chapter will illustrate the use of the echocardiogram in women. Furthermore, it will highlight some differences in the standardization of echocardiographic measurements as well as some technical challenges in women. Echocardiography is often the primary diagnostic tool to diagnose patients with structural heart disease. Structural heart diseases such as atrial septal defects, mitral valve prolapse (MVP), and pulmonary arterial hypertension are more commonly seen in women. Also, the utilization of stress echocardiography in women to diagnose underlying coronary artery disease (CAD) is discussed and compared to other current imaging modalities. The usage of the echocardiogram in pregnant women is discussed in detail. Finally, the role of fetal echocardiography is highly useful to diagnose and manage fetal cardiac anomalies.

DIFFERENCES IN ECHOCARDIOGRAPHIC MEASUREMENTS AND TECHNICAL CONSIDERATIONS Reference values for chamber sizes, vessel diameters, and left ventricle (LV) mass differ between men and women

 Takotsubo Cardiomyopathy  Congenital Heart Disease  Echocardiography in Pregnancy, Peripartum

Cardiomyopathy, Fetal Echocardiography

(Table 78.1). The aortic root size, LV end systolic, and LV end diastolic dimensions are larger in men than in women.1–5 There are also differences in Doppler velocities and mitral annular velocities. In women, the diastolic early mitral annular velocities are higher using pulsed wave tissue Doppler imaging (TDI) compared to men. For example, in healthy women, the normal early diastolic early mitral annular velocities were 11.8 ± 3.2 cm/s in women and 10.8 ± 3.0 cm/s in men.5 When comparing the E-wave deceleration time in men versus women, it is shorter in women. Furthermore, it has been reported that the left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) volumes decrease with age in both men and women, but the changes are more pronounced in women. Also, the muscle mass and systolic function, assessed by left ventricular ejection fraction (LVEF), increase with age, but more so in women than men. In women who are obese or have large breasts, this poses a challenge to the sonographer. Furthermore, if it is technically difficult to obtain the ultrasound images due to the patient’s body size and/or pendulous breasts, then it proves to be even more difficult to interpret the images. Breast implants can also cause significant technical challenges. In 1992, silicone implants were removed from the market, however; there were some silicone implants being implanted and studied for investigative purposes.

Chapter 78: Echocardiography in Women

1887

Table 78.1: Reference Limits and Partition Values of Left Ventricular Mass and Geometry

Women

Men

Reference Range

Mildly Abnormal

Moderately Abnormal

Severely Abnormal

Reference Range

Mildly Abnormal

Moderately Abnormal

Severely Abnormal

67–162

163–186

187–210

≥ 211

88–224

225–258

259–292

≥ 293

43–95

96–108

109–121

≥ 122

49–115

116–131

132–148

≥ 149

Linear Method LV mass, g 2

LV mass/BSA, g/m

LV mass/height, g/m

41–99

100–115

116–128

≥ 129

52–126

127–144

145–162

≥ 163

LV mass/height2,7, g/m2,7

18–44

45–51

52–58

≥ 59

20–48

49–55

56–63

≥ 64

Relative wall thickness, cm

0.22–0.42

0.43–0.47

0.48–0.52

≥ 0.53

0.24–0.42

0.43–0.46

0.47–0.51

≥ 0.52

Septal thickness, cm

0.6–0.9

1.0–1.2

1.3–1.5

≥ 1.6

0.6–1.0

1.1–1.3

1.4–1.6

≥ 1.7

Posterior wall thickness, cm 0.6–0.9

1.0–1.2

1.3–1.5

≥ 1.6

0.6–1.0

1.1–1.3

1.4–1.6

≥ 1.7

66–150

151–171

172–182

> 193

96–200

201–227

228–254

> 255

44–88

89–100

101–112

≥ 113

50–102

103–116

117–130

≥ 131

2D Method LV mass, g 2

LV mass/BSA, g/m

Source: Reproduced from Roberto M. Lang, Michelle Bierig, Richard B. Devereux, et al. Recommendations for Chamber Quantification: A Report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, Developed in Conjunction with the European Association of Echocardiography, a Branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18:1440–63. (BSA: Body surface area; LV: Left ventricular; 2D: 2-dimensional). Bold italic values: Recommended and best validated.

A

B

Figs 78.1A and B: Breast implant. Two-dimensional transthoracic echocardiography. (A) Arrows point to images produced by a saline breast implant; (B) Apical four-chamber view. Arrow points to a breast implant and the arrowhead to a pacing wire in the region of the tricuspid valve, which shows fatty infiltration (F). A prominent moderator band (M) is seen in the right ventricle. (LA: Left atrium; LV: Left ventricle; RA: Right atrium). (Movie clips 78.1A and B).

Consequently, the majority of implants in the late 1990s and early 2000s are saline. Then, in 2006, the Food and Drug Administration (FDA) approved the first silicone filled implant for the use of breast augmentation. Even more recently, there have been approvals by the FDA for a new silicone gel-filled implant. This newer implant is

reported to have a more cohesive gel than the previous silicone implants.6 As the number of women having silicone breast implants is expected to increase, there will continue to be limitations in diagnostic cardiac testing such as echocardiography. Saline and silicone breast implants interfere with the penetration of ultrasound

1888


beams and produce artifacts6 (Figs 78.1A and B). Despite attempts from the sonographer to increase the gain or change the ultrasound wave’s frequency, the images are still of poor quality and cluttered with artifacts. These make interpretation of echo findings more difficult. The artifacts which are produced from the breast implants are similar in some ways to the artifacts caused by air in the lung. To obtain interpretable echocardiographic views, the echocardiographer often needs to find alternative windows such as the subcostal approach which avoids passage of the ultrasound beam through the implants.6 Sometimes, depending on the size of the breast implant, a sonographer can modify the standard echocardiographic views in order to prevent the ultrasound beam from crossing the silicone implant.6 However, even with attempts to reposition the probe in order to obtain better quality echocardiographic images, the images still remain suboptimal. Furthermore, there is significant limitation in the ability to interpret the study.

STRUCTURAL HEART DISEASE: MVP, MITRAL STENOSIS, AND MITRAL ANNULAR CALCIFICATION Mitral Valve Prolapse

between 5% and 15%. Using the more modern criteria, the prevalence of MVP in the general population is estimated at 2–5%.7 Comparing the two genders, women tend to have less posterior prolapse, less flail, but more leaflet thickening.8 Also, compared to men, women tend to have less frequent severe regurgitation. M-mode echocardiography allows for the diagnosis of MVP with obvious leaflet thickening and posterior bowing of the mitral valve apparatus during systole.7–9 On the twodimensional (2D) echocardiogram MVP is diagnosed by noting localized displacement of one or both leaflets into the left atrium with or without mitral regurgitation. Chordal rupture may complicate MVP (Figs 78.2 and 78.3). Women with MVP tend to have both cardiac as well as noncardiac abnormalities. Examples of this include skeletal abnormalities such as pectus excavatum and scoliosis.9 Other associations with MVP include atypical chest pain, easy fatiguability, abnormal electrocardiographic (EKG) response to exercise (ST-T changes), and a variety of atrial and ventricular arrhythmias. The collection of these symptoms in the setting of MVP is often termed the MVP syndrome (MVPS) or dysautonomia. It has been reported that the clinical features are due to autonomic dysfunction. Both the sympathetic and parasympathetic nervous systems are likely involved, but not well understood

Mitral valve prolapse (MVP) and regurgitation is seen more commonly in women. Some studies report that MVP affects ~6% of women. MVP was overdiagnosed during the 1970s and 1980s due to lack of strict echocardiographic criteria. Earlier studies estimated the prevalence of MVP

Mitral Valve Stenosis in Women

A

B

Epidemiologic studies conducted in Western countries have demonstrated a higher prevalence of mitral stenosis in women. The largest study conducted to date included

Figs 78.2A and B: Mitral valve prolapse in a 42-year-old patient. (A) Two-dimensional transthoracic echocardiography. Arrowhead points to prolapse of both mitral leaflets. (B) M-mode study was useful in demonstrating prolapse in mid to late systole (arrow). (AO: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RV: Right ventricle; SVC: Superior vena cava). (Movie clip 78.2).


A

1889

B

Figs 78.3A and B: Ruptured chordae tendinae and mitral valve prolapse in a 71-year-old female. Live/real time three-dimensional transesophageal echocardiography. (A) The arrowhead shows a ruptured chord of a severely prolapsing A2 segment of the anterior mitral valve leaflet (AML); (B) Color Doppler imaging. Numbers 1 and 2 point to two jets of severe MR. The arrowhead points to the ruptured chord. (LA: Left atrium; MV: Mitral valve; MR: Mitral regurgitation; PML: Posterior mitral valve leaflet). (Movie clips 78.3A and B). Source: Reproduced with permission from Nanda et al. Comparison of real time two-dimensional with live/real time three-dimensional transesophageal echocardiography in the evaluation of mitral valve prolapse and chordae rupture. Echocardiography. 2008;25:1131–7.

echocardiograms performed on 12,926 women and 11,339 males to evaluate for mitral stenosis.10 The prevalence for women is estimated at 1.8%. It is not clearly understood why the association with the female sex exists.10 Furthermore, it has been shown that women, in addition to being more prone to the development of rheumatic heart disease/mitral stenosis, are at higher risk of death in the setting of rheumatic heart disease.11 Figures 78.4 to 78.10 demonstrate various aspects of echocardiographic findings in rheumatic mitral valve disease. The color Doppler examination in Figures 78.4A to F nicely illustrates a turbulent jet in the LV which originates from the mitral valve as well as the prominent flow acceleration, characteristic of mitral stenosis. The continuous wave Doppler further illustrates the severity of mitral stenosis by demonstrating a significant mean gradient.

Mitral Valve Calcification Although mitral annular calcification is a chronic degenerative process and progresses with increasing age, it is more commonly seen in women, especially those over the age of 70 (Figs 78.11A to C). Consequences of mitral annular calcification may include mitral stenosis, mitral regurgitation, infective endocarditis, atrial arrhythmias, and heart block. It has been shown that the presence of mitral annular calcification on echocardiography may be

a marker of obstructive CAD, especially in the setting of anginal symptoms.12 Furthermore, in women, the absence of mitral annular calcification was a marker for the absence of obstructive CAD. However, this did not hold true for men.

ISCHEMIC HEART DISEASE/STRESS ECHOCARDIOGRAPHY/POLYCYSTIC OVARIAN SYNDROME Ischemic heart disease remains the leading killer in the United States. Although there have been advances in treating ischemic heart disease (IHD), there still remains a significant growth in prevalence of IHD. It has been shown in prior studies that 38% of deaths in women were related to CAD. This will only likely continue to increase as the population continues to age.13 Furthermore, more women than men, annually, have died from CAD, refuting the old belief that heart disease was a “man’s disease.” It has been shown that women who are critically at risk for CAD are often missed by the traditional approaches to disease management, partly because of atypical clinical presentation and low suspicion of index on the part of the examining physician. Women represent a unique and challenging patient population to the clinician. Women tend to have greater symptom burden and a lower prevalence of obstructive

1890


A

B

C

D

E

F

Figs 78.4A to F: Rheumatic mitral stenosis. Two-dimensional transthoracic echocardiography in a 45-year-old female with a history of rheumatic fever several years ago. (A) Arrow points to thickened mitral valve leaflets with a typical hockey-stick appearance visualized in the parasternal long axis view; (B) Short-axis view of the mitral valve (MV) at the leaflet tips. MV area measured 1.10 cm2 suggestive of fairly severe stenosis; (C) Color Doppler examination shows a turbulent jet (arrowhead) in the left ventricle (LV) originating from the MV. Note the prominent flow acceleration (arrow); (D) Color Doppler guided continuouswave Doppler show peak and mean gradients of 34 and 19 mm Hg, respectively; (E) Pressure half time assessment also showed severe MV stenosis with a valve area of 0.87 cm2; (F) Live/real time three-dimensional study confirmed the presence of severe stenosis with no calcification of commissures. There was only mild mitral regurgitation. The patient is on the wait list for percutaneous mitral valvuloplasty (Movie clips 78.4A, C, and F). (AO: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RV: Right ventricle).


1891

A

B

C

D

E

Figs 78.5A to E: Rheumatic mitral stenosis in 34-year-old female patient with history of paroxysmal nocturnal dyspnea. Two-dimensional transthoracic echocardiography. (A and B) Parasternal long axis (A) and apical four-chamber (B) views show thickened mitral valve leaflets with doming in diastole indicative of mitral stenosis. The subvalvular apparatus is also thickened; (C) Color Doppler examination shows mild mitral regurgitation and moderate aortic regurgitation; (D) Live/real time three-dimensional transesophageal echocardiography demonstrates a very small mitral orifice (arrow) indicative of severe stenosis; (E) Severe mitral regurgitation developed following percutaneous mitral valvuloplasty (Movie clips 78.5A to E). (PA: Pulmonary artery; RA: Right atrium). Other abbreviations as in previous figure.

CAD on coronary angiography, compared to men. Interestingly, women often times have a more adverse outcome despite having lower angiographic disease burden.

In women, the prevalence of obstructive CAD is low before menopause, the average age of menopause being ~51 years.13 After the age of menopause, the prevalence

1892


of CAD in women increases to become almost equal with men at the age of 70 years (Figs 78.12 and 78.13). While women may have overall lower rates of hypertension and smoking, both elderly hypertensive women and young female smokers are very prominent at risk subgroups. Population studies have also demonstrated that women

have lower total cholesterol measurements until about the age of 50 years. Above the age of 50 years, women tend to have greater values. The risk factors for CAD seen in post menopausal women consist of obesity, hypertension, and dyslipidemia. The clustering of the risk factors commonly termed the metabolic syndrome consists of the following

A

B

Figs 78.6A and B: Female patient with rheumatic involvement of mitral and tricuspid valves. Transthoracic three-dimensional echocardiography. (A) Apical four-chamber view showing thickened mitral (MV) and tricuspid (TV) valves. (B) Cropping of the three-dimensional data set and en face viewing shows a very small mitral orifice in diastole indicative of severe stenosis. Note absence of calcification in the commissures. In comparison, the TV shows a much larger opening consistent with absence of significant stenosis. The movie clip shows fairly preserved motion of anterior (A) and posterior (P) leaflets but marked restriction of the septal (S) leaflet of the tricuspid valve. The septal leaflet is identified by its close proximity to the ventricular septum. The anterior and posterior leaflets are recognized by their anterior and posterior locations in relation to the left ventricular outflow (LVO) tract. The three-dimensional technique is considered the gold standard for assessing the mitral orifice area because, unlike two-dimensional echocardiography, the cropping plane can be positioned exactly parallel to the flow limiting orifice tip. Also, three-dimensional echocardiography easily assesses all three leaflets of the TV en face which is difficult with two-dimensional imaging (Movie clip 78.6). (LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle).

A Figs 78.7A and B

B


C

1893

D

Figs 78.7A to D: Mitral stenosis and regurgitation in a female patient. Transthoracic three-dimensional echocardiography. (A) Apical four-chamber view shows restricted mobility of both mitral valve (MV) leaflets which are thickened; (B) Cropping of the three-dimensional data set was performed to view the mitral orifice (arrow) at its tip. Planimetry was consistent with significant stenosis. Note presence of calcification in the body of the posterior leaflet but the anterior leaflet and both commissures are free of calcium; (C) Mosaic color signals in the left atrium with a prominent flow acceleration point to severe mitral regurgitation; (D) Meticulous cropping of the three-dimensional data set was done to view en face the vena contracta of the mitral regurgitation jet. This was performed practically at the level of the mitral leaflets between the flow acceleration and the regurgitant jet. It measured more than 0.6 cm2 indicative of severe regurgitation (Movie clip 78.7). Other abbreviations as in previous figures.

A

B

Figs 78.8A and B: (A) Rheumatic mitral stenosis and regurgitation in a female patient. Transesophageal two-dimensional echocardiography. Four-chamber view shows thickening of both mitral leaflets with restricted motion. Note thickening of chordal apparatus also; (B) Color Doppler examination demonstrates significant mitral regurgitation (MR) (Movie clips 78.8A and B). Other abbreviations as in previous figures.

conditions: insulin resistance, dyslipidemia [elevated triglycerides, low high-density lipoprotein (HDL)], hypertension, and abdominal obesity. The chest pain symptoms which women experience may be explained by the metabolic alterations which occur. This may result in

shifting energy substrates toward myocardial and peripheral glucose metabolism. Therefore, the traditional stress testing which is based on demand ischemia may fail to detect obstructive CAD in subsets of women without a significant coronary stenosis.13

1894


A

B

Figs 78.9A and B: Rheumatic mitral stenosis and regurgitation in a female patient. Transesophageal three-dimensional echocardiography. (A) En face view of the mitral valve (MV) shows mild narrowing of the thickened MV consistent with mild to moderate stenosis; (B) Systolic view shows noncoaptation of the mitral leaflets indicative of significant mitral regurgitation. (AV: Aortic valve). (Movie clip 78.9).

A

B

Figs 78.10A and B: Rheumatic mitral stenosis in another female patient. Transesophageal three-dimensional echocardiography. (A) The left atrium is viewed from the top and shows a large clot attached to the supero-posterior wall. The mitral valve (MV) is heavily calcified; (B) Three-dimensional two-chamber view demonstrates clots (arrowheads) in the body and appendage of the left atrium (Movie clips 78.10A and B). Abbreviations as in previous figures.

Using Stress Echocardiography in Women In some patients with obstructive CAD, resting echocardiograms may demonstrate tell-tale wall motion abnormalities or an akinetic or dyskinetic area with fibrotic scar formation may reveal the presence of an old myocardial infarction which may have been silent or undiagnosed. However, in most patients the diagnosis of obstructive CAD

is made by stress echocardiography. Treadmill exercise echocardiography is most commonly used because it results in greater patient oxygen consumption and therefore a higher sensitivity in detecting exercise induced wall motion abnormalities and diagnosing CAD as compared to pharmacologic agents such as dobutamine. The usage of pharmacologic agents (dobutamine or dipyridamole) to perform stress echocardiography helps to overcome the challenges of women who are incapable of maximal


1895

A

B

C

Figs 78.11A to C: Mitral annulus calcification in an 80-year-old female. Two-dimensional transthoracic echocardiography. (A to C) Arrowhead points to a heavy mitral annular calcification while the arrows show aortic annular calcification. The aortic valve leaflets are also calcified with restrictive opening and continuous-wave Doppler demonstrated high velocity consistent with significant stenosis (Movie clips 78.11A and B). (AO: Aorta; LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RA: Right atrium; RV: Right ventricle).

exercise. The advantages of stress echocardiography include the lower cost, absent radiation exposure, and the ability to image both ventricular function as well as cardiac structures. However, the utility of echocardiography can be limited if factors such as obesity exist which will limit acoustic windows. Furthermore, it is known that as women progress through menopause, they seem to have a greater loss in physical functioning when compared with men. Thus, if there is reduced exercise tolerance, the utility of stress echocardiography is markedly reduced. Acquisition of peak stress echocardiography images is limited by the experience of the sonographer and the clinician. Even with the limitations, exercise echocardiography is highly accurate at detecting CAD in women. Both the sensitivity and specificity of stress echocardiography are comparable to radionuclide techniques with the added advantage that one does not have to cope with breast shadows which may interfere with accurate interpretation when reading radionuclide studies in women. Stress

echocardiography is very useful in diagnosing 2 and 3 vessel disease with accuracy exceeding 80% to 85% but, like radionuclide testing, is less useful in diagnosing 1 vessel disease especially involving the circumflex artery. Contrast echocardiography serves as a valuable adjunct to stress echocardiography in patients with suboptimal acoustic windows. Intravenous injections of commercially available contrast agents produce full opacification of both right and left ventricular cavities resulting in complete delineation of the endocardial borders facilitating accurate assessment of wall motion abnormalities. Echo contrast agents consist of microbubbles of a nontoxic gas smaller or same size as the red blood cells and they travel with them into the coronary circulation and hence they opacify the ventricular myocardium also. This property has been used to evaluate myocardial perfusion abnormalities developing during stress echocardiography by demonstrating areas of reduced or absent opacification providing corroborative evidence of the presence of

1896


A

Figs 78.12A and B: (A) Aortic atherosclerosis in a 72-year-old female with coronary artery disease, systemic hypertension and type 2 diabetes mellitus presenting with chest pain. Two-dimensional transthoracic echocardiography. Suprasternal examination. Arrowhead points to a mobile plaque in the proximal descending thoracic aorta (DA); (B) Aortic atherosclerosis in the same patient as above. Two-dimensional transesophageal echocardiography performed to rule out aortic dissection. Arrowhead in the left panel points to a large mobile plaque in the anterior portion of the DA, arrowhead in the right panel demonstrates a large ulcer in the plaque posteriorly. Ischemic heart disease in a 75-year-old female. Two-dimensional transthoracic echocardiography. The parasternal long-axis view shows dyskinesis of the proximal left ventricular posterior wall (PW). (Movie clips 78.12A to C). (ACH: Aortic arch; IA: Innominate artery; LA: Left atrium; LCC: Left common carotid artery; PA: Pulmonary artery; AO: Aorta; LA: Left atrium; RV: Right ventricle; SVC: Superior vena cava; VS: Ventricular septum).

B obstructive CAD. More recently, live/real time threedimensional (3D) echocardiography is increasingly used together with contrast echocardiography in an attempt to further enhance the accuracy of stress echocardiography in assessing CAD. With 3D echocardiography, it is possible to capture the whole LV in the pyramidal shaped 3D data set which can then be cropped in a systematic and sequential manner to examine all ventricular walls and segments for stress induced motion abnormalities. This obviates the limitations of the 2D technique which produces only thin slice-like sections of the LV at any given time precluding comprehensive assessment of all segments. Apical foreshortening, common with 2D echocardiography, is avoided or reduced with the 3D approach which also has been shown to have much less intra- and interobserver variability in the assessment of left ventricular function. Another advantage is the 3D data can be stored in the equipment or offline and can

be recropped at will any time by the same or different cardiologist to double check the findings. A significant disadvantage relates to the quality of 3D images which is lower than 2D images and hence the technique is useful only in patients with good acoustic windows and in those in whom the image quality has been enhanced by contrast echocardiography. Although not commonly used, there are reported cases where transesophageal echocardiogram has actually revealed the diagnosis of CAD. It should be standard protocol to interrogate the left and right coronary arteries when they are visualized during a routine transesophageal echocardiogram exam. Figures 78.13A to M nicely demonstrate images of CAD. Notice the utilization of pulsed Doppler interrogation which reveals high diastolic velocities, consistent with severe stenosis. The coronary arteriograms included confirm the severity of the stenosis suspected by TEE.


A

B

C

D

E

F

Figs 78.13A to F

1897

1898


G

H

I

J

K

L

Figs 78.13G to L


1899

Figs 78.13A to M: Coronary stenosis in a 61-year-old female. Transesophageal echocardiographic examination. (A) Top arrow points to dilatation of the proximal left anterior descending coronary artery (LAD), whereas the bottom arrow demonstrates turbulent flow in mid-LAD. Pulsed Doppler interrogation of this area revealed a high diastolic velocity of 1.3 m/s (arrowhead in the inset), consistent with significant stenosis; (B) Top arrow points to turbulent flow in mid-LAD, whereas the bottom arrow shows turbulent flow in the more distal portion of LAD; (C) Arrow demonstrates narrowing in the first diagonal branch (arrowhead) of LAD. Continuous-wave Doppler interrogation reveals a very high diastolic velocity of 3.0 m/s (arrowhead in the inset) indicative of very severe stenosis; (D) Arrows show large segments of proximal, mid and distal segments of LAD visualized in this view; (E) Arrow demonstrates the presence of turbulent flow in the proximal right coronary artery; (F) Pulsed Doppler interrogation (arrowhead) of right coronary artery (RCA) M demonstrates a high velocity of 1.3 m/s (arrowhead in the inset) indicative of significant stenosis; (G) Arrow points to the presence of turbulent flow in the left circumflex coronary artery; (H) Arrow points to the origin of the left circumflex coronary, which appears normal. However, reversed flow (blue) with turbulent flow signals (arrowhead) is noted in the mid and distal portions of the circumflex vessel, consistent with filling from collaterals and significant stenosis. Doppler interrogation of this area shows a high diastolic velocity of 1.0 m/s (arrowheads in the inset); (I) Arrowhead demonstrates turbulent flow signals in the intramyocardial coronary arteries consistent with stenosis; (J) The interventricular vein (V) is imaged next to the dilated LAD (arrow). Note that the flow in the interventricular vein is in the opposite direction of LAD flow; (K) Coronary angiogram. The top arrowhead demonstrates 90% stenosis at the origin of the diagonal branch. The proximal LAD is dilated, and beyond the dilatation, the mid-LAD shows 50% stenosis (just beyond the bottom arrowhead). Note multiple areas of significant stenosis in the more distal segments of LAD; (L) Arrow points to total occlusion of proximal circumflex coronary artery. Retrograde filling of more distal portions of the circumflex vessel from collaterals was noted; (M) Coronary angiogram. The arrow points to significant stenosis in the proximal right coronary artery. Note significant stenosis in the mid and distal portions. (AO: Aorta; LA: Left atrium; LM: Left main coronary artery; LV: Left ventricle; MV: Mitral valve; PA: Pulmonary artery; RVO: Right ventricular outflow tract). Reproduced with permission from Nanda et al. Transesophageal echocardiographic diagnosis of coronary stenosis in a stroke patient. Echocardiography. 1999;16:589–92. In Movie clip 78.13, 1, Left anterior descending coronary artery; 2, Diagonal branch; 3, Proximal right coronary artery; 4, circumflex artery; 5, Intramyocardial coronary arteries (cannot be visualized by angiogram). V, coronary vein. Upper arrow shows proximal LAD. Lower arrow shows distal LAD. Arrowhead points to post-stenotic dilatation of the diagonal branch.

Polycystic Ovarian Syndrome/Syndrome X in Women Women with polycystic ovarian syndrome (PCOS) have been shown to be at higher risk for CAD compared to women without PCOS. Women with PCOS have risk factors which mirror a risk factor profile for that of a man. These risk factors include: anovulation, hyperandrogenism, and insulin resistance. PCOS could be thought of as the best example of syndrome X. If the cluster of risk factors known as the metabolic syndrome/syndrome X are indeed risk factors of atherosclerosis and CAD, then women with PCOS should have more atherosclerosis than women without PCOS, especially at younger ages.14 Therefore, these women with PCOS would need to be followed as the risk of developing obstructive CAD would be higher.

TAKOTSUBO CARDIOMYOPATHY Takotsubo cardiomyopathy is a very common clinical entity which occurs far more often in women than in

men (9:1 female/male ratio). The echocardiographic features include transient dyskinesia/akinesia usually localized to the apex of the LV (see Movie clips 78.26A and 78.26B in chapter on Nonobstructive Cardiomyopathy). Associated involvement of the left atrium has also been reported.11 In some patients only the middle portion of the ventricle is involved. The clinical presentation is very similar to that of acute coronary syndrome. The clinical history often reveals that the person has been under extreme emotional or physical stress which precipitates the abrupt onset of symptoms, including chest pain and shortness of breath. Examples of emotional stressors include grief, fear, anger, relationship conflicts, and financial problems. Examples of physical stressors include acute asthma exacerbation, surgery, chemotherapy, or stroke. This form of cardiomyopathy has a predilection for women, specifically those over the age of 50.15,16 Only 10% of cases have been reported to occur in men. Usually, patients present to the emergency department with concerns of having a myocardial infarction. Initially, both

1900


Takotsubo and acute coronary syndromes share a similar presentation, with abnormalities in the electrocardiogram (ECG) as well as biomarkers. In fact, this syndrome has been reported to represent 1.5% to 2.2% of acute coronary syndrome that presents with ST elevation or Q-waves on EKG.16,17 As a result, most patients are taken to the cardiac catheterization laboratory and are found to have normal coronary arteries in addition to the unique shape of the LV which is seen during the LV gram. This unusual shape of the LV, which resembles a Japanese octopus pot, is what has given Takotsubo its name. The classic case of stress induced cardiomyopathy is characterized by the presence of apical ballooning involving all left ventricular walls with a hyperdynamic base. These abnormalities are not limited to single coronary artery territory. There are theories to explain why the apex is affected and the base remains unaffected. This could be due to the fact that the apex is considered to be more responsive to adrenergic stimulation.11,15–19 This assumes that the catecholamine surge is the mechanism of Takotsubo.15 Echocardiography can prove to be very useful in the early diagnosis of this disease, and could actually prevent patients from undergoing unnecessary cardiac catheterizations given the detection of wall motion abnormalities not confined to typical coronary artery distribution in association with recent emotional or physical stressors. Echocardiography is also useful in assessing complications of Takotsubo such as clot formation in the LV apex and in the follow-up of these patients. Some of these patients show full recovery with complete normalization of wall motion abnormalities while in others residual wall motion abnormalities persist for a long time.

Vector velocity imaging (VVI) has been used to demonstrate that in patients with Takotsubo cardiomyopathy, there is both LV systolic and diastolic longitudinal dysfunction, not just systolic radial dysfunction.11 Traditional 2D echocardiography is typically used to assess radial dysfunction. VVI uses a tracking algorithm which incorporates both velocities of set points (i.e. mitral annulus and tissue-cavity border) as well as speckle tracking. The result is segmental quantitative velocity, strain, and strain rate. VVI has demonstrated that there are definitive reductions in both longitudinal systolic and diastolic dysfunction in Takotsubo cardiomyopathy.11 It has also been shown that there is improvement in the longitudinal function with time. Furthermore, there has been evidence to suggest that the left atrium is also affected in Takotsubo cardiomyopathy.11 Specifically, the left atrium’s systolic strain and strain rate and the diastolic velocity and strain rate are reduced. However, there is some data to suggest that there is improvement in the involved walls of the left atrium.11

A

B

Figs 78.14A and B

CONGENITAL HEART DISEASE Atrial Septal Defects Congenital heart disease seems to have an association with gender. Defects which involve the inflow tract such as the atrial septal defect and Ebstein’s (see Figures 57, 58, and 59 in chapter on Three-Dimensional Echocardiography in Congenital Heart Disease) are seen most commonly in females (Figs 78.14 and 78.15). Of patients with secundum atrial septal defects (ASDs), 65–75% are female. In contrast, there is equal gender distribution for both sinus venosus and ostium primum ASDs.20–24 Outflow tract abnormalities such as aortic stenosis and transposition


C

1901

Figs 78.14A to C: Secundum atrial septal defect in a 53-year-old female. Two-dimensional transthoracic echocardiography. (A and B). Apical four-chamber views show an atrial septal defect (arrows) with flow signals moving from the left atrium (LA) into the right atrium (RA). The right ventricle (RV) is enlarged; (C) is a suprasternal view in the same patient showing continuity of flow signals (arrow) between the pulmonary artery (PA) and the descending thoracic aorta (DA) indicative of an associated patent ductus arteriosus. (ACH: Aortic arch, LV: Left ventricle). Movie clips 78.14A to C.

Fig. 78.15: Secundum atrial septal defect in a 37-year-old female. Two-dimensional transesophageal echocardiography. Arrow points to flow signals moving from the left atrium into the right atrium through a secundum defect. Abbreviations as in previous figure. Movie clip 78.15 is from another female patient demonstrating en face visualization of a secundum atrial septal defect (upper arrow) using live/real three-dimensional tranesophageal echocardiography. Note a large rim in relation to the aorta (AO), tricuspid valve (lower left arrow), and mitral valve (MV). Lower right arrow points to the pulmonary valve. (PA: Pulmonary artery). Other abbreviations as in previous figure.

of the great arteries are more commonly seen in men. Atrial and ventricular septal defects also have a significant association with pulmonary hypertension. There has been some thought that the secundum ASD begins the cascade of vascular injury ultimately resulting in the pulmonary vascular remodeling and finally the development of pulmonary arterial hypertension. This could explain the gender disparities in pulmonary arterial hypertension.23

Pulmonary Hypertension Pulmonary arterial hypertension is typically defined as a measured mean pulmonary artery pressure (mPAP)

greater than 25 mm Hg, in conjunction with a normal cardiac output and normal pulmonary capillary wedge pressure (Figs 78.16 to 78.18).25 The association with the female sex is quite interesting. In fact, women have a 35% higher risk of developing pulmonary hypertension.25,26 Idiopathic pulmonary arterial hypertension is thought to be rare, with an incidence of 2 to 5/million/year. However, it is much more common in women compared to men with a reported ratio of 2.5:1.25,26 Various genetic mutations and polymorphisms have been reported to be associated with idiopathic pulmonary arterial hypertension, and none appear to be sex-linked.

1902


A

B

C

D

Figs 78.16A to D: Severe systemic level pulmonary artery pressure in a 37-year-old female with primary pulmonary hypertension. Two-dimensional transthoracic echocardiography. Apical views. (A) Note the marked enlargement of both the right ventricle (RV) and the right atrium (RA). The atrial septum bulges prominently into the left atrium (LA). Movie clip 78.8A shows diastolic bulging of the ventricular septum into the left ventricle (LV) indicative of right-sided volume overload; (B) Color Doppler examination shows the presence of severe tricuspid regurgitation (TR); (C) Continuous-wave Doppler examination reveals a very high pulmonary artery systolic pressure of 118 mm Hg (arrow); (D) Bubble study shows delayed appearance (after 4 beats) of the micro bubbles (arrowhead) in the left heart consistent with intrapulmonary shunting. This is related to dilatation of the pulmonary arterioles. (LV: Left ventricle; TV: Tricuspid valve). (Movie clips 78.16A to C).

In the included figures, specifically Figure 78.16, there is an excellent example of severe pulmonary hypertension in a young woman. The classic features of pulmonary hypertension include the marked enlargement of both the right ventricle and right atrium. Furthermore, there is diastolic bulging of the interventricular septum from right to left indicating the significant right-sided volume overload. Color Doppler highlights the severe tricuspid regurgitation seen in cases of pulmonary hypertension. A bubble study should always be performed in a case of pulmonary hypertension as it will reveal the presence of

intrapulmonary shunting. Intrapulmonary shunting is seen when there is a delayed appearance of microbubbles in the left side of the heart.

ECHOCARDIOGRAPHY IN PREGNANCY, PERIPARTUM CARDIOMYOPATHY, FETAL ECHOCARDIOGRAPHY Many physiological changes develop in many organ systems during the course of pregnancy. Cardiac output increases by 30% to 40% during the first trimester of


A

1903

B

Figs 78.17A and B: Severe pulmonary hypertension with right-sided involvement. Two-dimensional transthoracic echocardiography. (A and B) The tricuspid valve (TV) annulus is dilated with systolic noncoaptation (arrow) of the leaflets leading to severe tricuspid regurgitation (arrowhead). The pulmonary annulus is also dilated resulting in severe pulmonic valve regurgitation (PR). (CS: Coronary sinus; DA: Descending aorta; PV: Pulmonary valve; RA: Right atrium; RV: Right ventricle). (Movie clips 78.17A and B).

A

B

C

Figs 78.18A to C: Pulmonary artery aneurysm in a 21-year-old female patient with familial primary pulmonary hypertension. Twodimensional transthoracic echocardiography. (A) The pulmonary artery (PA) is markedly enlarged at 4.89 cm; (B) The right ventricle (RV) is larger than the left ventricle (LV) in the apical four-chamber view. Note displacement of the ventricular septum into the LV during systole; (C) Bubble study was negative for intracardiac or intrapulmonary shunting. (LA: Left atrium; MV: Mitral valve; PV: Pulmonary valve; RA: Right atrium; TV: Tricuspid valve). (Movie clips 78.18A to C).

1904


pregnancy. These changes can be seen on Doppler echocardiography with increased blood flow velocities and more prominent color Doppler flow signals in the cardiac cavities. Increased color Doppler flow signals in the region of the atrial septum may mimic an atrial septal defect especially in the presence of septal dropouts common in the apical four-chamber view. In this instance, continuity of color flow signals between the two atria in the region of the septal dropout may result in an erroneous diagnosis of a secundum atrial septal defect. At 8 to 11 weeks, an average cardiac output of 6.7 L/min will increase to 8.7 L/min at 36 to 39 weeks. This increase is mostly due to an increase in stroke volume, but also a more rapid heart rate. Also, there is a reduction in systemic vascular resistance. It is these changes which characterize the hyperdynamic circulation seen in pregnancy. On the echocardiogram, hyperkinetic ventricular wall motion is evident during this period of pregnancy.

Peripartum Cardiomyopathy

A

B

C

D

Figs 78.19A to D

In some women, the extra workload of the heart results in ventricular failure in the peripartum period (Figs 78.19A to G). Peripartum cardiomyopathy is characterized by systolic dysfunction, ventricular dilatation, and secondary mitral regurgitation, all well assessed by echocardiography. Thrombus formation especially in the left ventricular apex may be noted. This is a worrisome complication because of the potential for embolization and anticoagulants are essential. Anticoagulants like warfarin which facilitate the natural clot lytic mechanisms present in the blood stream work by first initiating a small area of liquefaction within the middle portion of a thrombus and this gradually spreads all the way to the periphery eventually resulting in complete resolution of the thrombus. Thus, on serial follow-up of 2D transthoracic echocardiograms the size of a thrombus may appear unchanged and anticoagulant


1905

F

E

G

Figs 78.19A to G: Peripartum cardiomyopathy. Live/real time three-dimensional transthoracic echocardiography in a 29-year-old female. (A) Arrow points to a large clot in the left ventricular (LV) apex. Both ventricles showed poor function; (B to D) A transverse plane (TP) section through the clot (B) shows a large area of echolucency (arrow) consistent with clot lysis (C and D). This indicated that the clot had practically completely dissolved and only a thin rim remained; (E) Schematic showing coagulation cascade and thrombus lysis. Plasminogen-activating factor (PAF) is secreted by endothelialized mesenchymal cells lining the microscopic crypts which develops within the thrombus. PAF activates plasminogen to plasmin which digests fibrin leading to thrombus lysis. (F and G) A TP section taken at the attachment point of the clot shows it to be highly echogenic consistent with collagen. This patient had been on anticoagulant therapy for a long time but on the two-dimensional study the clot did not appear to regress. However, the three-dimensional technique was useful in assuring us the effectiveness of anticoagulant therapy with almost complete clot resolution. The remainder of the clot regressed completely with no clinical or laboratory evidence of embolization (Movie clips 78.19). (vWF: von Willebrand factor; TF: Tissue factor; WBC: White blood cell; RBC: Red blood cell; CF: Clotting factors). Other abbreviations as in previous figures.

therapy ineffective although the thrombus in fact may be undergoing progressive liquefaction and resolution from within. In these cases, it is important to perform live/real time 3D echocardiography which can provide multiple short-axis sections of the thrombus and comprehensively assess the presence and extent of clot lysis. The technique can also assess the cross-sectional size and nature of the area of the attachment of the thrombus to the ventricular wall and this may provide information regarding its potential for embolization. For example, a mobile thro-

mbus with a small tenuous cross-sectional attachment site may be more prone to embolization than one with a much larger attachment area. Also, a bright echogenic attachment area suggests increased collagen content and fibrosis providing a more firm and stable attachment of the clot to the ventricular wall. Women with peripartum cardiomyopathy will usually present shortly after childbirth, but there are some women who will have the clinical presentation consistent with peripartum cardiomyopathy late in the third trimester.

1906


In high risk pregnancies, fetal echocardiography plays a very important role in evaluating normal and abnormal

fetal cardiac anatomy and physiology (Figs 78.20 to 78.22). M-mode studies of the mitral valve and Doppler tracings of mitral and tricuspid inflow have been found useful in evaluating fetal arrhythmias.27 Using both 2D and 3D fetal

A

B

C

D

E

F

Fetal Echocardiography

Figs 78.20A to F


1907

G

Figs 78.20A to G: Normal fetus. Live/real time three-dimensional echocardiographic study. (A) 31-week-old fetus. Arrowhead points to the foramen ovale. Arrowhead in (B) denotes the ductus arteriosus connecting aorta (AO) to pulmonary artery (PA); (C to F) 19-week-old fetus. Arrowhead points to foramen ovale visualized in a four-chamber view (C) and from top (D). Color Doppler image shows physiological right to left shunting (arrowhead, E). Arrowhead in F points to a normal tricuspid valve. Both atrial septum (AS) and ventricular septum (VS) are viewed en face in this image; (G) 22-week-old fetus. Color Doppler image shows ascending aorta (AA), aortic arch (ACH) and descending thoracic aorta (DA). (IVC: Inferior vena cava; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). Source: Reproduced with permission from Maulik et al. Live Three-dimensional echocardiography of the human fetus. Echocardiography. 2003; 20:715–21.

A

B

C

D

Figs 78.21A to D

1908


E

F

G

H

I

J

Figs 78.21E to J


K

L

M

N

1909

Figs 78.21A to N: Complete atrioventricular septal defect in 36-week-old fetus. Live/real time three-dimensional echocardiographic study. (A to D) Four-chamber views cropped to show the common atrioventricular valve (V) and the defect (asterisks). Arrowhead in C points to the atrial septum. (E to F) The pyramidal section has been cropped from the top and rotated toward the examiner to display all five leaflets of V: posterior (P), left lateral (L1), left anterior (A1), right anterior (A2), and right lateral (L2). Small portions of the ventricular septum (S) and atrial septum (AS) have been retained to show their relationship to V. V is open in E and closed in F. (G) Arrowhead demonstrates multiple chordal attachments of V to S; (H to J) En face viewing of the defect (asterisk) from above (H), from the inferior aspect (I) and from the right side (J); (K to M) Five-chamber view shows the aorta (AO) arising from LV. In M, the pyramidal section has been cropped to show regurgitation (R) from the right-sided component of V. (N) Arrowhead shows the ductus arteriosus. (AV: Aortic valve; S: Ventricular septum). (Movie clip 78.21). Source: Reproduced with permission from Maulik et al. Live three-dimensional echocardiography of the human fetus. Echocardiography 2003;20:715–21.

echocardiography allows diagnosis of many congenital cardiac lesions. This information is crucial to the obstetrician and the pediatric cardiologist who can discuss the prognosis with the parents and also aids them in the management of these conditions in the neonatal period. For example, in complete atrioventricular septal defects, valve

attachments to papillary muscles in the opposite ventricle are not amenable to surgical repair and hence these babies carry a dismal prognosis. Also, cyanotic babies with dextro transposition of the great vessels need intervention immediately after birth. In some specialized centers in the country, percutaneous intrauterine interventions

1910


Fig. 78.22: Thickened tricuspid valve in a 20-week-old fetus. Live/real time three-dimensional echocardiographic study. The arrowhead points to a markedly thickened tricuspid valve. (LA: Left atrium; RA: Right atrium). Source: Reproduced with permission from Maulik et al. Live three-dimensional echocardiography of the human fetus. Echocardiography. 2003; 20:715–21.

have been successfully performed to correct aortic and pulmonary valve stenosis.27–30 This is done in an attempt to prevent the development of hypoplastic left and right heart syndromes in the newborn. 3D echocardiography actually provides more information in assessing the severity. Both valves are enclosed in the 3D data sets, and they can be cropped to view the maximum flow limiting orifice area. It is the direct en face visualization coupled with the quantification of the stenotic semilunar valve orifice which makes 3D echocardiography more reliable than 2D.27–30 Furthermore, there is added information obtained from 3D echocardiography due to the ability to view cardiac chambers, valve leaflets, and great vessels in three dimensions. This added information can prove to be useful in guiding catheter based interventions in the intrauterine setting after birth. Other pathologic conditions seen in women are found in Figures 78.23 to 78.37 with corresponding movie clips.

A

B

C

D

Figs 78.23A to D: Systemic hypertension. The patient is a 37-year-old female with very severe hypertension. Two-dimensional transthoracic echocardiography. Parasternal long-axis (A), short-axis (B), and apical four-chamber (C) views. Note the marked concentric hypertrophy of both the ventricular septum (VS) and the posterior wall (PW). The left atrial appendage (LAA) is clearly delineated and is free of any clot. (D) M-mode study shows left ventricular hypertrophy. (AO: Aorta; LA: Left atrium; MV: Mitral valve; RA: Right atrium; RV: Right ventricle). (Movie clips 78.23A to C).


Fig. 78.24: Left ventricular hypertrophy in a 30-year-old patient with chronic renal disease. Two-dimensional transthoracic echocardiography. Both the ventricular septum (VS) and the posterior wall (PW) are hypertrophied and contain echo densities related to fibrosis. (AO: Aorta; LA: Left atrium; RV: Right ventricle). (Movie clip 78.24).

A

1911

Fig. 78.25: Mitral valve vegetations in a 43-year-old female with infective endocarditis. Live/real time three-dimensional transesophageal echocardiography. The black arrow (horizontal arrowhead in the video clip) points to a mitral valve vegetation involving the A1 segment and commissure. Note the presence of central perforation. Two other vegetations are also seen involving A2 and A3 segments of the anterior mitral leaflet. (AO: Aorta; PV: Pulmonary valve; TV: Tricuspid valve). (Movie clip 78.25). Source: Reproduced with permission from Hansalia et al. The value of live/real time three-dimensional transesophageal echocardiography in the assessment of valvular vegetations. Echocardiography. 2009;26:1264–73.

B

Figs 78.26A and B: Mitral valve vegetation in a 32-year-old female with infective endocarditis. Live/real time three-dimensional transesophageal echocardiography. (A) The arrowhead points to a large mitral valve vegetation with a central perforation; (B) The lower arrowhead points to an annular abscess and the upper arrowhead points to the mitral valve. (AO: Aorta; PV: Pulmonary valve). (Movie clips 78.26A and 78.28B). Source: Reproduced with permission from Hansalia et al. The value of live/real time three-dimensional transesophageal echocardiography in the assessment of valvular vegetations. Echocardiography. 2009;26:1264–73.

1912

A


B

Figs 78.27A and B: Right-sided heart failure resulting from severe tricuspid regurgitation due to infective endocarditis. Two-dimensional transthoracic echocardiography. (A) Arrowheads denote vegetations on the tricuspid valve leaflets; (B) Color Doppler examination shows severe tricuspid regurgitation (TR). (AO: Aorta; CS: Coronary sinus; LV: Left ventricle; RA: Right atrium; RV: Right ventricle). (Movie clips 78.27A part 1, 78.27A part 2 and 78.27B).

A

B

Figs 78.28A and B: Systemic lupus erythematosus in a young female patient. Two-dimensional transthoracic echocardiogram. (A and B). Parasternal long-axis view shows the presence of pericardial effusion (PE, A) which resolved during follow-up (B). There are no valvular abnormalities. (AO: Aorta; CS: Coronary sinus; DA: Descending aorta; LA: Left atrium; LV: Left ventricle; PW: Posterior wall; RV: Right ventricle; SVC: Superior vena cava; VS: Ventricular septum). (Movie clips 78.28A and B).


A

1913

B

Figs 78.29A and B: Metastatic left pleural effusion in a 53-year-old female with chronic myeloid leukemia. Two-dimensional transthoracic echocardiography. (A) In the parasternal long-axis view, the pleural effusion (PLE) is diagnosed by noting an echo free-space posteriorly extending beyond the descending thoracic aorta (DA); (B) PLE is readily diagnosed by placing the ultrasound transducer in the posterior intercostal spaces with the patient sitting up. (LA: Left atrium; LB: Left back; LU: Lung; LV: Left ventricle; RV: Right ventricle). (Movie clips 78.29A and B).

A

B

Figs 78.30A and B: Bicuspid aortic valve in a young female. (A and B) Both two-dimensional (A: Left panel, systole; right panel, diastole) and three-dimensional (B) transthoracic echocardiography show the presence of a bicuspid aortic valve with horizontal cusp orientation. (AO: Aorta; LA: Left atrium; PV: Pulmonary valve; RA: Right atrium, RV: Right ventricle). (Movie clips 78.30A and B).

1914


A

B

Figs 78.31A and B: Bicuspid aortic valve. Two-dimensional transesophageal echocardiogram showing a bicuspid aortic valve imaged in long (A) and short (B) axis views. The arrow in A points to valve redundancy and prolapse into the left ventricular (LV) outflow tract. In B, the cusps are vertically oriented and appear to be equal in size. (AO: Aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve). (Movie clips 78.31A and B).

A

B

C

D

Figs 78.32A to D


E

G

1915

F

Figs 78.32A to G: Quadricuspid aortic valve in a 54-year-old female. (A and B) Two-dimensional transthoracic echocardiography. The aortic valve (AV) appears bicuspid. (C to E) Multiplane twodimensional transesophageal echocardiography. (C and D) AV leaflets (numbered in D) are well seen. The arrow in C points to diastolic noncoaptation of AV leaflets which resulted in significant aortic regurgitation. (E) The arrow points to severe aortic regurgitation. (F and G) Live/real time three-dimensional transthoracic echocardiography show a quadricuspid AV with four numbered leaflets clearly visualized. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve). (Movie clips 78.32A to D, 78.32F part 1 and part 2). Source: Reproduced with permission from Burri et al. Live/real time three-dimensional transthoracic echocardiographic identification of quadricuspid aortic valve. Echocardiography. 2007;24:653–5.

Fig. 78.33: Muscular outflow ventricular septal defects. Twodimensional transthoracic echocardiography. Short-axis view at the level of the LV outflow tract demonstrates two adjacent ventricular septal defects (1 and 2). Note the two defects are not related to the tricuspid or pulmonary valve and hence are not in the perimembranous or supracristal location. (AO: Aorta; PV: Pulmonary valve; RA: Right atrium; RV: Right ventricle; TV: Tricuspid valve). (Movie clip 78.33).

1916


A

B

C

D

Figs 78.34A to D: Levo (corrected) transposition of the great vessels with a ventricular septal defect and pulmonary artery banding in a 25-year-old female. Parasternal long-axis views (A and B) show a large ventricular septal defect with flow signals moving from the pulmonary ventricle (morphological LV) into the aorta (AO). The arrow points to a band in the pulmonary artery (PA) surgically placed in an attempt to protect the patient from pulmonary hypertension. Two-dimensional (C) and three-dimensional (D) transthoracic shortaxis views show the aortic valve and the AO located directly anterior to pulmonary valve (PV) and PA indicative of transposition of the great vessels. (CS: Coronary sinus; LV: Left ventricle; MV: Mitral valve; RA: Right atrium). (Movie clips 78.34A to D).

A Figs 78.35A and B

B


1917

C

Figs 78.35A to C: Embolization of a left atrial appendage clot into the systemic circulation in a 67-year-old female undergoing coronary artery bypass surgery. Two-dimensional transesophageal echocardiography. This was initially performed to rule out the presence of mitral regurgitation because an apical systolic murmur was heard pre-operatively. No significant mitral regurgitation was noted but a clot was demonstrated in the left atrial appendage (LAA) (A). The patient had two brief episodes of atrial fibrillation in the past which probably accounted for the formation of the clot. Before the surgeon could make any decision, the clot was noted to embolize from the appendage into the systemic circulation (B and C). In the immediate post bypass period, the left femoral pulsation was found to be absent pointing to the location of the clot which was successfully removed. The patient had an uneventful recovery without any stroke or other complication. (AO: Aorta; LA: Left atrium; LV: Left ventricle). (Movie clip 78.35).

A

B

C

D

Figs 78.36A to D

1918


E

F

Figs 78.36A to F: Combined valvar and supravalvar aortic stenosis. Live/real time three-dimensional transthoracic echocardiography. (A) Horizontal arrowhead points to supravalvar aortic stenosis produced by calcification at the sinotubular junction. The vertical arrowhead shows heavy mitral annular calcification; (B) Supravalvar stenotic orifice viewed in short axis (arrowhead); (C) Short-axis view at the level of the aortic valve (AV) leaflets demonstrating mild valvar stenosis. Live/real time three-dimensional transthoracic echocardiography in a patient with calcification at the aortic sinotubular junction but no stenosis; (D) The arrowheads point to prominent calcifications at the sinotubular junction viewed in long axis; (E) Short-axis view at the sinotubular junction shows a large orifice (arrowhead) that measured 2.5 cm2; (F) Short-axis view at the level of the AV (left) and immediately above it (right). The AV orifice measured 1.7 cm2 by planimetry, consistent with mild aortic stenosis. The arrowhead in the right panel points to sinotubular calcification protruding into the aortic lumen imaged just beyond the AV leaflets. (AO: Ascending aorta; LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery; RA: Right atrium; RV: Right ventricle; RVO: Right ventricular outflow tract; TV: Tricuspid valve). (Movie clip 78.36). Source: Reproduced with permission from Rajdev et al. Live/real time three-dimensional transthoracic echocardiographic assessment of combined valvar and supravalvar aortic stenosis. Am J Geriatr Cardiol. 2006;15:188–90.

A Figs 78.37A and B

B


C

1919

D

Figs 78.37A to D: Paravalvular mitral regurgitation in a 69-year-old female. Paravalvular mitral regurgitation (arrowhead) is noted by transthoracic (A) and transesophageal (B) echocardiography. (C and D) Represent live/real time three-dimensional images showing two plugs (arrowheads) used to successfully close the leak percutaneously in the cardiac catheterization laboratory. Small arrows in D point to intact sutures. (AV: Aortic valve; LA: Left atrium; LV: Left ventricle; MR: Mitral regurgitation; MVR: Mitral valve replacement; RA: Right atrium; RV: Right ventricle). (Movie clips 78.37A to D).

CONCLUSION Echocardiography proves to be a very useful diagnostic tool for women, but it is not without its challenges. There are structural heart diseases that occur more commonly in women, and it is important to remember that women can often have atypical presentations, which sometimes delays the accurate diagnosis. Often, the diagnosis is delayed in women because it is thought that the likelihood of a certain disease process is rather low. Hopefully, this discussion has helped to illustrate and highlight the structural heart disease processes that are actually seen more frequently in women.

REFERENCES 1. Dalen H, Thorstensen A, Vatten LJ, et al. Reference values and distribution of conventional echocardiographic Doppler measures and longitudinal tissue Doppler velocities in a population free from cardiovascular disease. Circ Cardiovasc Imaging. 2010;3;614–22. 2. Lang RM, Bierig M, Devereux RB, et al. Recommendations for Chamber Quantification: A Report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, Developed in Conjunction with the European Association of Echocardiography, a Branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18:1440–63.

3. Lauer MS, Larson MG, Levy DL. Sex-specific reference M-mode values in adults: population-derived values with consideration of the impact of height. J Am Coll Cardiol. 1995;26:1039–46. 4. Sadaniantz A, Hadi BJ, Saint Laurent L. Gender Differences in Mitral Inflow Parameters of Doppler Echocardiography. Echocardiography. 1997;14(5):435–40. 5. Vasan RS, Larson MG, Benjamin EJ, et al. Echocardiographic reference values for aortic root size: the Framingham Heart Study. J Am Soc Echocardiogr. 1995;8(6):793–800. 6. Movahed MR. Impairment of echocardiographic acoustic window caused by breast implants. Eur J Echocardiogr. 2008;9(2):296–7. 7. Avierinos JF, Inamo J, Grigioni F, et al. Sex differences in morphology and outcomes of mitral valve prolapse. Ann Intern Med. 2008;149(11):787–95. 8. St John Sutton M, Weyman AE. Mitral valve prolapse prevalence and complications: an ongoing dialogue. Circulation. 2002;106(11):1305–7. 9. Gaffney FA, Karlsson ES, Campbell W, et al. Autonomic dysfunction in women with mitral valve prolapse syndrome. Circulation. 1979;59(5):894–901. 10. Movahed MR, Ahmadi-Kashani M, Kasravi B, Saito Y. Increased prevalence of mitral stenosis in women. J Am Soc Echocardiogr. 2006;19(7):911–3. 11. Burri MV, Nanda NC, Lloyd SG, et al. Assessment of systolic and diastolic left ventricular and left atrial function using vector velocity imaging in Takotsubo cardiomyopathy. Echocardiography. 2008;25(10):1138–44. 12. Atar S, Jeon DS, Luo H, et al. Mitral annular calcification: a marker of severe coronary artery disease in patients under 65 years old. Heart. 2003;89(2):161–4.

1920


13. Shaw LJ, Bairey Merz CN, Pepine CJ, et al. WISE Investigators. Insights from the NHLBI-Sponsored Women’s Ischemia Syndrome Evaluation (WISE) Study: Part I: gender differences in traditional and novel risk factors, symptom evaluation, and gender-optimized diagnostic strategies. J Am Coll Cardiol. 2006;47(3 Suppl):S4–S20. 14. Talbott E, Guzick D, Clerici A, et al. Coronary heart disease risk factors in women with polycystic ovary syndrome. Arterioscler Thromb Vasc Biol. 1995;15(7): 821–6. 15. Citro R, Caso I, Provenza G, et al. Right ventricular involvement and pulmonary hypertension in an elderly woman with tako-tsubo cardiomyopathy. Chest. 2010;137 (4):973–5. 16. Donohue D, Movahed MR. Clinical characteristics, demographics and prognosis of transient left ventricular apical ballooning syndrome. Heart Fail Rev. 2005;10(4): 311–6. 17. Donohue D, Ahsan C, Sanaei-Ardekani M, et al. Early diagnosis of stress-induced apical ballooning syndrome based on classic echocardiographic findings and correlation with cardiac catheterization, J Am Soc Echocardiogr. 2005; 18:1423. 18. Hurst RT, Prasad A, Askew JW 3rd, et al. Takotsubo cardiomyopathy: a unique cardiomyopathy with variable ventricular morphology. JACC Cardiovasc Imaging. 2010; 3(6):641–9. 19. Haghi D, Athanasiadis A, Papavassiliu T, et al. Right ventricular involvement in Takotsubo cardiomyopathy. Eur Heart J. 2006;27(20):2433–9. 20. Verheugt CL, Uiterwaal CS, van der Velde ET, et al. Gender and outcome in adult congenital heart disease. Circulation. 2008;118(1):26–32.

21. Warnes CA. Sex differences in congenital heart disease: should a woman be more like a man? Circulation. 2008; 118(1):3–5. 22. Webb G, Gatzoulis MA. Atrial septal defects in the adult: recent progress and overview. Circulation. 2006;114(15): 1645–53. 23. Rothman KJ, Fyler DC. Sex, birth order, and maternal age characteristics of infants with congenital heart defects. Am J Epidemiol. 1976;104(5):527–34. 24. Samánek M. Boy:girl ratio in children born with different forms of cardiac malformation: a population-based study. Pediatr Cardiol. 1994;15(2):53–7. 25. McLaughlin VV, McGoon MD. Pulmonary arterial hypertension. Circulation. 2006;114(13):1417–31. 26. Rich S, Dantzker DR, Ayres SM, et al. Primary pulmonary hypertension. A national prospective study. Ann Intern Med. 1987;107(2):216–23. 27. Maulik D, Nanda NC, Hsiung MC, et al. Doppler color flow mapping of the fetal heart. Angiology. 1986;37(9):628–32. 28. Nanda, NC, Sudhakar S, Joshi D, et al. Role of three dimensional echocardiography in prevention and early detection of cardiac diseases. In: Chopra, HK, editor. Heart Protection Book. Delhi, India: ASSOCHAM and Ministry of Health and Family Welfare, Govt. of India, 2011 and ASSOCHAM released on September 2011: 43–7. 29. Singh A, Mehmood F, Romp RL, et al. Live/Real time threedimensional transthoracic echocardiographic assessment of aortopulmonary window. Echocardiography. 2008;25(1): 96–9. 30. Singh A, Romp RL, Nanda NC, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006;23(7):598–608.

1921

CHAPTER 79 Echocardiography in the Elderly Gopal Ghimire, Navin C Nanda, Kunal Bhagatwala, Nidhi M Karia

Snapshot  AorƟc Atherosclerosis and PenetraƟng AorƟc Ulcer  AorƟc Valve Sclerosis  AorƟc Stenosis  AorƟc Aneurysm  AorƟc DissecƟon

INTRODUCTION Aging induces significant alteration in the structure and function of the cardiovascular (CV) system. Although these adaptive changes are physiological and asymptomatic, they are at times difficult to distinguish from preclinical disease. Furthermore, presence of coexisting CV diseases can modulate these adaptive responses and complicate the clinical picture. In this chapter, we aim to discuss the CV peculiarities in elderly patients.

AORTIC ATHEROSCLEROSIS AND PENETRATING AORTIC ULCER (FIGS 79.1A TO C) Atherosclerosis is a systemic disease with a strong predilection to involve the aorta especially in the elderly. A study revealed that the average age of those with large/complex plaques (measuring ≥ 4 mm in size) in the aorta on transesophageal echocardiography (TEE) was 70 years.1 In the Stroke Prevention: Assessment of Risk in a Community (SPARC) study,2 of 588 patients (average age, 66.9 years) undergoing TEE, the overall prevalence of aortic plaque in any location was 43.7%, of which complex plaque (defined as ≥ 4 mm or mobile)

 LeŌ Ventricular Mass, Dimensions and FuncƟon  Echocardiography in Stroke PaƟents: Assessment of

Coronary Stenosis  Mitral Annular CalcificaƟon  ProstheƟc Valves

was 7.6%. The prevalence of aortic plaques increased progressively from 8.4% in the ascending aorta to 31% in aortic arch and 44.9% in the descending aorta. Similarly, the prevalence of the complex plaques in the respective locations was 0.2%, 2.2%, and 6.0%. The atherosclerotic plaque on the aortic arch is now considered as the third leading cause of embolic stroke.1 The prevalence of ≥4 mm aortic plaque in stroke patients (14–21%) is on the same order of magnitude as that of the other two important causes of embolic stroke—carotid artery disease (10–13%) and atrial fibrillation (18–30%).3,4 Although the aortic plaque can be construed as a surrogate marker for generalized atherosclerosis and stroke risk, the French Aortic Plaque in Stroke (FAPS) study established causality between the stroke and complex aortic arch atheroma as the odds ratio (OR) for stroke in patients with plaques in the descending aorta (unlikely to embolize upstream to the cerebral vessels) was only 1.5 for the plaques ≥ 4 mm when compared with an OR of 13.8 for those in the aortic arch.4 Furthermore, this study also established a gradient between increasing plaque thickness and incremental stroke risk with OR significantly greater in those with a plaque thickness ≥ 4 mm: the OR for stroke in patients with submillimeter plaques was 1.0 (no increased risk), in contrast to 3.9 for 1–3.9 mm plaques, and 13.8 for plaques

1922


A

B

C

Figs 79.1A to C: Aortic atherosclerosis in three elderly patients. (A and B) Two-dimensional (2D) transesophageal echocardiography (A) Upper arrow points to a mobile atherosclerotic plaque and the lower to a fixed one in the descending thoracic aorta (AO). Arrowhead shows prominent ulceration in the plaque; (B) Arrow, in another patient, shows a mobile plaque in the ascending aorta (AA); (C) 2D transthoracic echocardiography. Arrow, in a different patient, shows a fixed plaque in the proximal abdominal aorta (AB) imaged using the subcostal approach (Movie clips 79.1A to C). (L: Liver).

≥ 4 mm. Although transthoracic echocardiography (TTE) can visualize the aortic root and proximal ascending aorta, the aortic arch, and the descending thoracic aorta from various windows, the resolution of the TTE is not optimal enough for accurate evaluation of the atherosclerotic plaque. In contrast, the TEE probe is closer to the aorta and can be used at a higher frequency, thus allowing for higher resolution than on TTE. An accurate and detailed evaluation of the aorta, including the origin of the great vessels, is possible,5 and there is excellent interobserver and intraobserver variability.6 Very uncommonly, the atherosclerotic lesion penetrates the internal elastic lamina into the media, leading to formation of a penetrating aortic ulcer (PAU). The natural history of this entity may involve progression to a variable degree of intramural hematoma (IMH) formation, pseudoaneurysm formation, aortic rupture, or late aneurysm.7 Although PAUs can occur throughout the aorta, it

has predilection for the thoracic and abdominal aorta more than in the arch or ascending aorta. PAU typically mimics presentation of the classic aortic dissection with acute chest or back pain, and indeed PAUs constitute up to 2–8% of acute aortic syndrome.7 However, 25% of patients with PAU are asymptomatic and the lesions were identified during axial imaging for other indications.8 The patients are typically older and hypertensive individuals with multiple coronary risk factors and coexisting vascular disease. Imaging techniques for PAU include aortography, computed tomography (CT), magnetic resonance imaging (MRI), and TEE with TEE showing aortic atherosclerotic plaque with focal ulceration of the intima. The management of the patient with PAU must be individualized depending on the location and disease progression. The general consensus is that a large or unstable PAU or a PAU with progression should have surgical intervention. The predictors of disease progression are refractory or recurrent

Chapter 79: Echocardiography in the Elderly

Fig. 79.2: Aortic valve sclerosis. Three-dimensional transesophageal echocardiography. Short axis cropping at the tip of the aortic valve (AV) obtained from a parasternal long-axis data set shows a large aortic orifice (arrowhead in the Movie clip 79.2) with no evidence of stenosis. The AV leaflets are mildly thickened consistent with sclerosis. (LA: Left atrium; TV: Tricuspid valve). (Movie clip 79.2). Source: Reproduced with permission from Nanda NC, Hsiung MC, Miller AP, Hage FG. Live/Real Time 3D Echocardiography. Oxford, UK: Wiley-Blackwell; 2010.

1923

Fig. 79.3: Aortic valve sclerosis. Three-dimensional transesophageal echocardiographic reconstruction. Shows a thickened tricuspid aortic valve (AV) with no significant pressure gradient. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.3).

pain, ulcer craters > 20 mm in diameter or 10 mm in depth, interval worsening of aortic hematoma, periaortic hematoma, expanding pseudoaneurysm, increasing pleural effusion, and rupture. Due to segmental nature of this entity, endovascular intervention is an attractive alternative, especially since these patients tend to be elderly and have multiple comorbidities.9–13

AORTIC VALVE SCLEROSIS (FIGS 79.2 TO 79.4) Murmur A systolic murmur in the aortic area is present in approximately 50% of elderly population.14,15 The reliability of clinical examination alone in the assessment of aortic sclerosis or stenosis (AS) in the elderly is poor.16 In one study, 17% of patients who were deemed to have AS only on physical exam were found to have mitral regurgitation (MR) as the only significant finding.17 Most of the murmurs in the elderly subjects are related to sclerotic aortic valve (AV) leaflets, flow into tortuous, noncompliant great vessels, or a combination of these. Such murmurs must be distinguished from murmurs caused by mild to severe valvular AS, or atrioventricular valve regurgitation, which are prevalent in this age group. The ACC/AHA recommends

Fig. 79.4: Aortic valve sclerosis. Three-dimensional transesophageal echocardiographic reconstruction demonstrates a mildly thickened, obliquely oriented bicuspid aortic valve (AV) with raphe and no significant gradient consistent with AV sclerosis. (LA: Left atrium; RA: Right atrium; RV: Right ventricle). (Movie clip 79.4).

that echocardiography should not be done for patients who have a Grade II or softer midsystolic murmur identified as innocent or functional by an experienced observer.18

Prevalence, Pathophysiology, and Echocardiographic Findings AV sclerosis is focal thickening of the AV leaflets with commissural sparing, normal leaflet mobility, and no evidence of left ventricular outflow tract (LVOT) obstruction with

1924


transaortic gradient of <2.5 m/s. The degenerative process may not be confined to the leaflets alone; it can also extend to the aortic root. Furthermore, 50% of patients with AV sclerosis also have associated mitral valve sclerosis.19 Approximately, one in four subjects more than 65 years may have AV sclerosis and the prevalence increases with advancing age.20 However, AV sclerosis is not an inevitable consequence of aging as 25–45% of octogenarians have no evidence of AV calcification.21,22 The relationship between AV sclerosis and age is nonlinear with a sharp increase in prevalence at age about 65 years in men and at age about 75 years in women. Despite normal hemodynamics, AV sclerosis is not benign; it is independently associated with poor CV outcome, for example, with a relative risk of death of 1.66 [95% confidence interval (CI) 1.23–2.23]23 or of a new coronary event of 1.76 (95% CI 1.52–2.03).24 In LIFE study (Losartan Intervention For End point reduction in hypertension), composite CV outcome occurred in 15% of hypertensive patients with AV sclerosis, compared with 8% patients with normal AV.25 Patients admitted with chest pain and AV sclerosis had a higher incidence of CV events (16.8% vs 7.1%) and worse event-free survival than did those without AV sclerosis.26 In the CV health study, the rate of death from any cause or death from CV cause of patients with AV sclerosis was twice that of patients with a normal AV.23 Two-dimensional (2D) echocardiography is the best noninvasive modality to diagnose AV sclerosis. The mobility of AV leaflets and the severity and extent of calcification on the cusps and in the aortic annulus along with peak and mean pressure gradients across the AV should be measured. The absence of high gradients distinguishes it from significant AS. Three-dimensional (3D) echocardiography can supplement the 2D technique by providing a more comprehensive evaluation of AV anatomy, leaflet motion, and exact sites and degree of calcification. AV sclerosis may progress to AS. Of 2,131 patients with AV sclerosis, 15.9% developed AS over a mean follow-up of 7.4 years with 5.4% developing clinically significant (moderate to severe) AS.27 In another study of 400 patients with AV sclerosis followed for a mean duration of 44 ± 30 months, 32.75% developed some degree of AS with 2.5% developing severe AS defined as a peak jet velocity ≥ 4 m/s, 5.25% of patients progressed to moderate AS, which was defined as a peak jet velocity between ≥3.1 and ≤3.9 m/s, and 25% developed mild AS, which was defined as a peak jet velocity between >2 and ≤3 m/s.28

AORTIC STENOSIS Prevalence and Pathophysiology AS in adults is caused by a calcific process involving a normal trileaflet or congenital bicuspid aortic valve (BAV). This calcific process can progress from the base of the cusps to the leaflets, eventually causing a reduction in leaflet motion and effective valve area without leading to commissural fusion.29 The AV is more likely to be tricuspid in patients in their eighth, ninth, and tenth decades of life, and bicuspid in younger patients.30–32 However, a study revealed that three out of nine nonagenarians undergoing surgical AV replacement had bicuspid valves.33 In the Cardiovascular Health Study, AS was present in 2% of the entire study cohort (adults ≥ 65 years), 2.6% of those 75 years or older, and 4% of those 85 years or older. Changing demographic pattern in the western society and changing epidemiology of rheumatic heart disease have rendered calcific AS as one of the most prevalent valvular diseases. AS currently is considered the most frequent indication for valve replacement surgery, and the second most common indication for cardiac surgery in older adults, which is surpassed only by coronary artery bypass grafting (CABG).34

Two-Dimensional Echocardiography (Figs 79.5 to 79.7; Also see Fig. 78.11 in Chapter 78) Echocardiography is an integral part of the evaluation of AS in order to confirm the diagnosis, and assess its severity and evaluate its upstream consequences on the left ventricle (LV). Clinical signs and symptoms are of limited use in distinguishing critical from noncritical AS due to unsatisfactory sensitivity and specificity in the aged.35 Although cardiac catheterization is regarded as the gold standard for evaluation of valvular dysfunction, it is invasive and is associated with a higher risk of complications in the elderly. In a single center study, 22 of 101 patients with valvular AS who underwent retrograde catheterization of the AV had focal diffusion-imaging abnormalities in cranial MRI, a pattern consistent with acute cerebral embolic events after the procedure; three of these patients (3%) had clinically apparent neurological deficits.36 Thus, cardiac catheterization in the elderly portends substantial risk of clinically apparent cerebral embolism and frequent silent ischemic brain lesions. Cardiac catheterization is


A

B

C

D

1925

Figs 79.5A to D: A 79-year-old man with exertional angina and syncope. Two-dimensional transthoracic echocardiography. On the parasternal long-axis view (A) a calcified aortic valve with restricted opening is shown at the arrow. The maximal velocity across the valve on continuous wave (CW) Doppler is 4.1 m/s (B) with a velocity time integral (VTI) of 84 cm, which correspond to a peak gradient of 67 mm Hg and mean gradient of 35 mm Hg. The PW across the left ventricular outflow tract (LVOT) measured a velocity of 88.4 cm/s across the LVOT (C); (D) The aortic valve area and the dimensionless index are calculated, both corresponding to severe aortic stenosis. Notice that small errors in the measurement of the LVOT diameter will result in large errors in the calculated aortic valve area, while the dimensionless index is unaffected by this measurement. Adapted from Adegunsoye A, et al. Echocardiography. 2011;28:117–29.

currently recommended for assessment of severity of AS only in symptomatic patients when noninvasive tests are inconclusive or when there is a discrepancy between noninvasive tests and clinical findings regarding severity of AS.18 During echocardiography, it is of utmost importance to check for the consistency of different echocardiographic findings and with clinical assessment. In patients with severe AS, two-dimensional transthoracic echocardiography (2D TTE) shows augmented reflectance of the valvular cusps along with significant thickening and deformity. The valve leaflets are domed, less mobile, and with restricted leaflet excursion. In intermediate cases, the

free edge remains mobile despite immobility of the base, and fusion of the commissures does not occur primarily. If a discrete orifice can be demonstrated, then the valve area can be measured with planimetry, but direct planimetric measurements of the aortic orifice are of insufficient sensitivity and specificity as a result of the uncertainty that the plane of imaging is at the leaflet tips (where maximum stenosis commonly occurs) and is exactly parallel to the orifice. The determinants of pressure gradient across a stenotic valve are the valve orifice area and the transvalvular flow.37 Thus, in the presence of depressed cardiac output, relatively low pressure gradients may be obtained in patients with

1926


Fig. 79.6: Schematic. Because a stenotic jet consists of a small central region or “core” of high velocity and a larger outer region of lower velocity, the continuous wave Doppler cursor must be positioned in the jet core in addition to being aligned parallel to the jet direction to measure the maximum jet velocity. The threedimensional structure of the jet may cause the continuous wave cursor to appear to be correctly positioned in the jet while, in reality, the cursor may not be properly placed in the core. Therefore, after the initial alignment of the continuous wave cursor in the visualized jet, minimal transducer angulations are still required to interrogate the jet core, which may be in the azimuthal plane. Failure to interrogate the core results in an underestimation of the peak transvalvular velocity and thus the severity of the stenotic lesion. In this illustration, the aortic stenosis (AS) jet is shown to consist of a central core, which has the highest velocity, and an outer region of lower velocity flow surrounds this central core. The highest velocity is thus obtained if the continuous wave Doppler cursor is aligned parallel to the core of the jet (cursor 2), while lower velocities are recorded if the cursor is positioned outside the core (cursors 1, 3, 4, and 5). Source: Reproduced with permission from Nanda NC. Textbook of Color Doppler Echocardiography. Philadelphia, PA: Lea and Febiger, Inc; 1989:178–90.40

severe AS. Conversely, during exercise or other high-flow states, significant pressure gradients can be measured in minimally stenotic valves. Therefore, comprehensive assessment of AS requires measurement of transvalvular flow, mean transvalvular pressure gradient using Doppler interrogation, and calculation of the effective valve orifice area. Doppler echocardiography utilizes ultrasound reflecting off moving red blood cells to measure the velocity of blood flow and allows the noninvasive assessment of normal and abnormal blood flow patterns. Continuous wave Doppler echocardiography measures the highest velocities along the plane of interrogation, but for reliable velocity measurements, the cursor must be aligned parallel to the flow jet. The accuracy of this task is

facilitated by using color Doppler as a guide that enables easy visual identification of the aortic jet.38 The peak and mean velocities across the AV can be translated into peak and mean pressure gradients by using the modified Bernoulli’s equation.39 An important caveat is that even with color Doppler guidance, optimization in the cursor position is paramount to obtain the maximum velocity. This is because the AS jet has an outer region of relatively low velocity flow and a central core of higher velocity that can be appreciated only when viewed in three dimensions (Fig. 79.6).40 Malalignment of the beam with the flow across the valve will lead to underestimation of the velocity and, therefore, of the severity of AS. In order to minimize this source of error, the velocities have to be measured using several echocardiographic windows, the apical and right parasternal views, and the highest value assumed to correspond to the proper alignment.41 Since transvalvular velocity is squared in the equation, a small change in transvalvular velocity can result in a significant change in the transvalvular gradient. Estimation of the aortic valve area (AVA) can also be performed with the use of the continuity equation, which depends on the principle of the law of continuity of flow.42 This has been shown to be a reliable index of AS severity that correlates highly with cardiac catheterization measurements and surgical findings.43 This calculation entails measuring the LVOT diameter, the time velocity integral at the LVOT using pulsed wave Doppler, and the time velocity integral at the AV (using continuous wave Doppler, Fig. 79.2). LVOT crosssectional area is computed from the diameter assuming that the outflow tract has a circular configuration. The outflow tract diameter is measured immediately proximal to the attachment of the aortic leaflets during systole from the standard parasternal long-axis plane, and the largest inner diameter is selected.44 The peak LVOT velocity is estimated with the pulsed Doppler technique in the apical transducer position, with the sample volume placed 1.0–1.5 cm proximal to the AV to avoid the area of AS jet flow acceleration. The continuity equation is independent of transaortic flow and the presence of aortic or mitral insufficiency, and the equation has been validated in the presence of severe aortic incompetence.45 The continuity equation assumes that the LVOT diameter and the flow across the LVOT are measured at the same level, which is technically difficult since they are assessed in different echocardiographic views. Also, since continuous wave Doppler is used to measure the highest velocity across a straight path, it also assumes that there is no other form of LVOT obstruction other than AS such as supravalvular or subaortic stenosis. Nevertheless, the most frequent


A

B

C

D

E

F

1927

Figs 79.7A to F: Mitral and aortic annular calcification in a 99-year-old patient. Two-dimensional transthoracic echocardiography. (A and B) Parasternal long-axis view (A) and parasternal short-axis view (B) at the level of the aortic valve show heavy calcification involving the aortic valve, and aortic and mitral annuli (1), mitral valve (2), and mitral subvalvular apparatus (3, 4); (C) Parasternal short-axis view at the level of the mitral valve shows calcification involving the posterior mitral leaflet and mitral annulus (2); (D) Apical four-chamber view showing calcification involving the ventricular septal muscle (arrow). Arrowhead points to a pacemaker in the right atrium (RA); (E) Apical two-chamber view showing calcification involving the mitral valve and annulus (2). R represents a reverberatory artifact deep in the left atrium from the calcified mitral valve. (F) Color Doppler-guided continuous wave Doppler interrogation of the aortic valve demonstrates peak and mean gradients of 30 and 18 mm Hg, respectively (arrow), consistent with mild aortic stenosis. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RV: Right ventricle) (Movie clips 79.7A to E).

1928


Table 79.1: Limitations of Two-Dimensional Transthoracic/Color Doppler Echocardiography

The continuity equation provides an indirect rather than direct estimation of the AVA True LVOT velocity can be difficult to determine from the area of increased flow acceleration Accurately measuring LVOT diameter may be difficult (e.g. in patients with aortic or mitral annular calcification) Doppler cursor may not be in the jet core even with color Doppler guidance, resulting in AS severity underestimation Localized high gradients may be present in the region of the aortic valve; these do not reflect the true gradient across the AV, resulting in overestimation of AS severity AS severity cannot be correctly assessed in the presence of coexisting subaortic or supravalvular stenosis Source: Adapted from Vengala et al.52 (AS: Aortic stenosis; AV: Aortic valve; AVA: Aortic valve area; LVOT: Left ventricular outflow tract).

source of error in measuring the AV area is due to the inaccuracy of LVOT diameter measurement. This is especially difficult in older adults with accumulation of calcium at the annulus. Furthermore, since the LVOT is often elliptical rather than circular in nature if measured proximal to the LV–aortic junction, 3D modalities of imaging may be more accurate in measuring the LVOT than 2D TTE.46 The age-related alteration in the LVOT geometry with reduction in the septoaortic angle with advancing age might render the outflow tract narrow in the parasternal long-axis view.47 Since the LVOT diameter is squared in the calculation of AVA, even minor errors in measurement will amplify the inaccuracy of estimation of AVA. This is particularly pertinent during evaluation of the progression of severity of stenosis in an individual patient, since large factitious variations in the calculated valve area can be due to erroneous measurements of the LVOT diameter. This limitation can be obviated by usage of the dimensionless index, which is simply the ratio of the velocity across the LVOT to that across the AV and completely eliminates the area of the LVOT from the equation.42 A ratio of 0.9–1.0 is considered as normal and a ratio of <0.25 is regarded as severe stenosis. Another potential source of error that is particularly relevant in older population is the overestimation of the severity of AS due to the phenomenon of pressure recovery, which leads to the overestimation of AS severity when measured by Doppler due to the conversion of kinetic energy upstream to potential energy downstream across the stenotic valve. This effect is further exaggerated in individuals with domed and tubular stenoses, a narrow ascending aorta (<3 cm), or a narrow LVOT (≤2 cm).48–51 Other situations in which Doppler echocardiography can potentially overestimate the severity of AS includes confounding of the true AS jet with localized high velocity gradients

presumably related to calcific areas in the AV, mistaken identification of a jet (the jet of MR can be mistaken for AS or the smaller velocity aortic jet may be contaminated with the much higher velocity signals from the associated MR jet), concomitant stenotic lesions present in tandem (such as supravalvular stenosis or discrete subaortic stenosis), and nonrepresentative jet selection (e.g. a post extrasystolic beat). Table 79.1 depicts the limitations of the transthoracic/color Doppler echocardiography for evaluation of AS. Multiplane transesophageal echocardiography (2D TEE) permits detailed evaluation of the morphology of the stenosed AV that may provide useful information about the etiology of AS (degenerative, rheumatic, or bicuspid) independent of the transthoracic acoustic window. By gradually advancing the transesophageal probe to detect the flow-limiting tip of the valve that is stenotic allows direct planimetric quantification of the anatomical AVA. The accuracy of this semi-invasive method may be limited by difficulties in obtaining the optimal imaging plane orientation at the level of the tip of the stenosed AV cusps. Prior studies found clinically important overestimation of effective AVA by TEE planimetry compared with flowderived methods with a variable reproducibility and accuracy.53–56 In geriatric population, precise planimetric quantification of AVA by 2D TEE poses unique challenges due to the altered aortoseptal angle with an obliquely placed aorta, prior valve replacement, or severely calcified valvular cusps, which cause acoustic shadowing and interfere with visualization. In clinical echocardiographic practice, AS is considered severe when the AVA is < 1.0 cm2, indexed AVA57 is < 0.6 cm2/m2, and the mean transvalvular gradient is > 40 mm Hg.18,57 Severe AS is unlikely if stroke volume (that translates into transvalvular flow) is normal and there is a mean pressure gradient of < 40 mm Hg.


Low Flow, Low Gradient Aortic Stenosis with Low Ejection Fraction (Fig. 79.8) In the presence of low transvalvular flow, lower pressure gradients may be encountered even in presence of severe AS; since the gradients are a squared function of flow, even a modest decrease in flow may lead to a significant reduction in gradient. A low-flow, low-gradient (LF-LG) state is encountered in 5 to 10% of patients with severe AS.58 Typically, these patients have severely depressed LV systolic function59–62 and portend a dismal prognosis irrespective of modality of treatment with survival rates of 50% at 3-year follow-up if treated medically, and 6 to 33% if treated surgically.58,61–63 LF-LG severe AS is defined as EOA 1.0 cm2 or 0.6 cm2/m2 when indexed for BSA, mean transvalvular gradient < 40 mm Hg, and left ventricular ejection fraction (LVEF) < 40% in the presence of a low-flow state that is defined as a cardiac index < 3.0 L/min/m2 and a stroke volume index < 35 mL/m2.57,64,65 Stroke volume can be measured by Doppler echocardiography,66–68 biplane Simpson method (2D TTE), or cardiac catheterization.69 However, the mere presence mean gradient of <40 mm Hg and small AVA and low LVEF does not definitely confirm LG LF severe AS, since mild-to-moderately diseased valves may not open fully due to low-flow state, resulting in a “functionally small valve area” (pseudosevere AS). In these cases, dobutamine

1929

stress echo (DSE) up to a maximum dosage of 20 μg/kg/min is useful to discriminate severe from pseudosevere AS and evaluate the LV contractile reserve.59,61 This test should be performed with great caution in the elderly because of the increased potential for ventricular arrhythmia especially in the presence of coexisting coronary artery disease (CAD). Typically, pseudosevere AS in the elderly shows a significant increase in AV opening and AVA with relatively little increase in gradient, whereas true severe AS is characterized by no significant increase in AVA even though there is significant change in LV ejection fraction and stroke volume as reflected by an increase in the LVOT velocity time integral (V TI). No change in AVA with <20% change in stroke volume or LVOT V TI points to poor LV contractile reserve. Patients with low-flow reserve constitute approximately 30–40% of patients with low LVEF, LF-LG AS, and its presence portends a higher operative mortality (22–33%) than those with normal flow reserve (5–8%).59–62 However, the postoperative LVEF recovery and the late survival rate in patients who survived surgery were equivalent to those with normal flow reserve70 and much better than in those with no flow reserve treated medically.66 In summary, the assessment of LV flow reserve by DSE is useful to estimate the operative risk but the absence of flow reserve is not predictive of recovery of LV function, improvement in symptomatic status, and late survival after surgery.61,62,70 The absence of LV flow reserve, therefore, should not preclude consideration of AVR in these patients.61,66 However, since the operative risk for surgical AVR is generally very high in the absence of flow reserve, transcatheter aortic valve replacement (TAVR) may be a valuable alternative in these patients.71

Paradoxical Low Flow, Low Gradient Aortic Stenosis with Preserved Ejection Fraction

Fig. 79.8: Dobutamine stress echocardiography to evaluate the left ventricular flow reserve and to distinguish the true severe aortic stenosis from pseudosevere aortic stenosis. (EOA: Effective orifice area (in square centimeters); EOAProj, projected EOA at normal flow rate (in square centimeters); P: Mean transvalvular gradient (in mm Hg); SV: Stroke volume).

As many as one third of patients with severe AS on the basis of AVA calculation have unequivocally low transvalvular gradients (mean gradient < 40 mm Hg) despite a preserved LV ejection fraction of >50%.72 These patients tend to be in the older age group, have small, concentrically hypertrophied LV with a lower LV diastolic volume index (52 ± 12 mL/m2), a higher level of LV global afterload reflected by a higher valvuloarterial impedance, and a lower overall 3-year survival a poor outcome if managed medically.72–74 The diagnosis is suggested on echo/Doppler studies by noting paradoxically low flows with a calculated

1930


stroke volume index of 35 mL/m2 or less in the presence of normal LV ejection fraction as well as decreased LV midwall shortening. Currently, paradoxically low-flow, low-gradient severe AS is considered a distinct clinical entity. The distinctive features of this entity are robust LV concentric remodeling and myocardial fibrosis, both contributing to the restrictive physiology. The fibrosis is mainly subendocardial and is responsible for marked attenuation of intrinsic LV systolic function, not evidenced by the LVEF, but rather by other more sensitive parameters directly measuring LV midwall or longitudinal axis shortening.74–77

Live/real time three-dimensional transthoracic echocardiography (3D TTE) with a full matrix–array transducer has

transformed the complex technique of 3D imaging into an efficient, cost-effective, and clinically viable procedure.78,79 Rotating the 3D data set and cropping from the aorta to the LVOT and stopping at the tips of the trileaflet or BAV allows for the direct planimetry of the stenotic valve and calculates AVA with increased confidence level.80–83 The inherent ability to present data in 2D cut-planes from a 3D data set permits assessment of angulated orifices and domed AVs as well as localizes and evaluates the exact individual sites of obstruction in patients with associated subvalvular, supravalvular, or tandem obstruction (see Figs 79.3 to 79.5).83–86 In low-flow states as in patients with severe AS and low cardiac output, 3D TTE may also supplement 2D TTE; the AVA can be directly inspected and measured following dobutamine infusion, which obviates reliance on 2D TTE/Doppler gradients that provide only indirect estimations of AS severity. Although 3D TTE can be performed in all patients with AS, it is especially important to perform 3D TTE when

A

B

C

Figs 79.9A to C: Aortic valve stenosis. Live/real time threedimensional transthoracic echocardiography. (A to C) Careful cropping of the parasternal long-axis data set at the flow-limiting tips of the aortic valve (AV) leaflets demonstrated a bicuspid morphology and severe stenosis. (LA: Left atrium; LV: Left ventricle). (Movie clips 79.9A to C Parts 1 to 4). Source: Reproduced with permission from Nanda NC, Hsiung MC, Miller AP, Hage FG. Live/Real Time 3D Echocardiography. Oxford, UK: Wiley-Blackwell; 2010.

Live/Real Time Three-Dimensional Transthoracic Echocardiography (Figs 79.9 to 79.16)


1931

A

B

C

Figs 79.10A to C: Another adult patient with bicuspid aortic valve stenosis. Live/real time three-dimensional transthoracic echocardiography. (A and B) The arrowhead in A points to thickened aortic valve (AV) leaflets with restricted opening motion viewed in parasternal long axis. Short-axis cropping at the AV tip demonstrates a severely stenotic bicuspid valve; (C) QLab cropping shows a small orifice consistent with significant AV stenosis. Despite the presence of a motion artifact, it was possible to assess the orifice size in this patient. (LA: Left atrium; LV: Left ventricle). (Movie clips 79.10A to C Parts 1 to 4). Source: Reproduced with permission from Nanda NC, Hsiung MC, Miller AP, Hage FG. Live/Real Time 3D Echocardiography. Oxford, UK: Wiley-Blackwell; 2010.

Fig. 79.11: Mild aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction showing a mildly calcified tricuspid aortic valve (AV) with minimal stenosis. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.11).

Fig. 79.12: Severe aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction. Demonstrates a heavily calcified, vertically oriented bicuspid aortic valve (AV) with a very small orifice indicative of severe stenosis. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.12).

1932


Fig. 79.13: Severe aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction. Demonstrates a heavily calcified, horizontally oriented bicuspid aortic valve (AV) with a very small orifice denoting severe stenosis. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.13).

A

B

Figs 79.14A and B: Severe aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction. (A) Shows a heavily calcified tricuspid aortic valve (AV) with small a very small orifice consistent with severe stenosis; (B) In addition, a perforation (arrowhead) is visualized in diastole in one of the cusps. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.14).

Fig. 79.15: Severe aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction. Demonstrates severe tricuspid aortic valve (AV) stenosis with a very small orifice but only mild calcification. (LA: Left atrium; RA: Right atrium; RV: Right ventricle) (Movie clip 79.15).


1933

Table 79.2: Indications for Performing Three-Dimensional Echocardiography in Older Adults with Suspected Aortic Stenosis

Increased likelihood of significant pressure recovery: • Aortic valve doming on two-dimensional echocardiography (in both bicuspid and tricuspid aortic valves) • Tubular, rather than discrete aortic stenosis • Narrow or borderline-narrow left ventricular outflow tract diameter (≤ 2.0 cm) • Small ascending aortic diameter (< 3.0 cm measured at or just beyond the sinotubular junction) Discrepancy between two-dimensional echocardiography and Doppler findings Discrepancy between two-dimensional echocardiography/Doppler and clinical findings A case can be made for performing three-dimensional echocardiography in all patients with suspected aortic stenosis because of the additional data provided and to avoid the dependence on gradients obtained by technicians; however, this may not be practical or cost-effective

A

B

Figs 79.16A and B: Severe aortic stenosis. Three-dimensional transesophageal echocardiographic reconstruction. (A) Demonstrates a horizontally oriented severely stenotic bicuspid aortic valve (AV) with a valve area of 0.9 cm2; (B) Diastolic frame shows a perforation (arrowhead) in the AV. (LA: Left atrium; RA: Right atrium; RV: Right ventricle; RVO: Right ventricular outflow tract) (Movie clip 79.16).

there is reason to believe that 2D TTE/Doppler may not provide an accurate assessment of AS severity (Table 79.2). However, it is important to recognize that in patients with poor acoustic windows or those with very heavily calcified valves, which are more commonly seen in the elderly, 3D TTE images may not be adequate quality to planimeter the aortic orifice. Some investigators have reported that this may occur in as many as 20% of patients, although in our experience it is possible to measure the AVA by 3D TTE planimetry in a much greater proportion of patients with AS. 3D TEE reconstruction or live/real time 3D TEE may supplement 3D TTE in patients with poor acoustic windows.

Ventricular Response to Aortic Stenosis Concentric hypertrophy is a compensatory response to chronic elevation of afterload and increased intracavitary

pressures due to AS. The increased muscle mass normalizes wall stresses by an increase in left ventricular wall thickness relative to the chamber size by operation of Laplace’s law.87 Unfortunately, this compensatory response is maladaptive because the hypertrophied heart may have reduced coronary blood flow per gram of muscle88 and also exhibit an attenuated coronary vasodilator reserve, even in the absence of epicardial CAD.89 The hemodynamic stress of exercise or tachycardia can elicit a maldistribution of coronary blood flow and subendocardial ischemia, which can contribute to systolic or diastolic dysfunction of the LV. Pressure overload left ventricular hypertrophy (LVH) has been shown to increase sensitivity to ischemic injury, with larger infarcts and higher mortality rates than in the absence of hypertrophy.90,91 In geriatric population especially in the female, an excessive or inappropriate degree of hypertrophy has been observed with wall thickness greater than is necessary to counterbalance

1934


the high intracavitary pressures. This response maintains the systolic wall stress relatively low and ejection fraction relatively high, but has been associated with high perioperative morbidity and mortality.92–94 In the geriatric patient with AS, the hemodynamic load to the LV is summation of the resistance offered by the stenotic AV and the attenuated systemic arterial compliance. Hence, description of the severity of the AS in elderly is rather simplistic if described merely by AVA and transvalvular gradients as it does not take into consideration the influence of altered systemic arterial compliance and systemic vascular resistance. The global LV hemodynamic load can be quantified by “valvuloarterial impedance” (Zva), which incorporates the degree of valve stenosis and the systemic arterial compliance.95,96 Zva has been shown to be superior to the conventional indices of AS severity in predicting LV dysfunction and patient outcome.73,95

Transcatheter Aortic Valve Replacement (Figs 79.17A to E) Standard surgical AV replacement in the elderly carries a high mortality in the immediate postoperative period, but subsequent to this the mortality in the long term approximates that in the younger patients. However, the presence of serious comorbidities and other contraindications often precludes surgery in these patients. In this regard, the advent of TAVR has been a boon for the elderly and is now considered a standard of care for patients with severe symptomatic AS who have a high risk or contraindications to conventional surgical AV replacement. This is a catheter-based procedure in which a prosthetic valve mounted on a catheter tip is implanted inside the preexisting stenosed AV with angiographic and echocardiographic guidance. Based on data from prospective randomized clinical trials, this procedure has been shown to confer improvement in survival in nonoperative candidates when compared to conventional medical treatment97 and confers equivalent survival benefit compared to open heart surgery in high-risk patients.98 During the procedure, accurate measurement of the AV annulus or ring is pivotal to select the most appropriate prosthetic valve size to avoid complications such as prosthesis migration, paravalvular aortic regurgitation,99 or aortic annulus rupture. Some paravalvular regurgitation leading to postoperative aortic insufficiency (AI) is common post TAVR and is known to occur in 22–40% of patients.100,101 Moderate or severe paravalvular aortic

regurgitation (AR) was seen in 12.2% of TAVR patients in the seminal PARTNER (Placement of Aortic Transcatheter Valves) trial, a significantly higher figure than seen in the surgical group (0.9%).98 AR, when more than just trace, has been shown to be a predictor of both in-hospital and long-term mortality.101 One of the important predictors of paravalvular AR and postprocedure AR is prosthesis– annular mismatch. Conventionally, the manufacturers’ recommendations on size selection had been based on 2D echocardiographic measurement of the AV annulus. However, the 2D echocardiographic measurement has been shown to significantly underestimate the AV annular dimensions.102–104 Furthermore, there is significant interobserver and intraobserver variability in measurement because of uncertainty about where in the dense calcium to place the cursor and also the frequent need for guessing where the leaflet hinge point is. 3D echocardiographic measurements may mitigate some of these problems105 but it still underestimates the annular dimension when compared to multidetector computerized tomographic (MDCT) measurements. MDCT is considered as the reference standard for measuring the aortic annulus in most centers. In the majority of patients, the AV ring is an oval structure with sagittal diameter being the minimum diameter and the coronal diameter being the maximum diameter of the annulus. Therefore, averaging the minimum and maximum diameter to get a mean diameter is a pragmatic way of sizing the annulus. However, in one third of the patients, the true minimum and maximum diameter will be at oblique angles and not in the true coronal and sagittal plane, respectively, and this leads to an imperfect and imprecise measurement in up to 33% of the patients.106 These shortcomings have prompted many TAVR centers to use a multimodality imaging approach in which all patients receive MDCT along with 2D TTE, and 2D and 3D TEE. Some of the complications of TAVR in the elderly such as stroke and paravalvular aortic regurgitation may be reduced with further impending improvements in the technique and development of improved valve design.

AORTIC ANEURYSM (FIGS 79.18A AND B) An aortic aneurysm represents a pathologically dilated segment of the aorta that has the propensity to expand and rupture. The Olmsted county study estimated the incidence of thoracic aortic aneurysm (TAA) to be 5.9 per 100,000 person-years compared with 350 cases for abdominal aortic aneurysms (AAA).107 However,


1935

A

B

C

D

E

Figs 79.17A to E: Transcatheter aortic valve replacement (TAVR) in an 85-year-old patient. Two-dimensional (2D) and live/real time three-dimensional (3D) transesophageal echocardiography. (A) Pre procedure. 3D short-axis view shows a calcified aortic valve (arrow) with a very small irregular orifice consistent with severe aortic stenosis; (B) During procedure. Arrow shows a catheter in the region of the aortic root and valve imaged using the 3D approach; (C to E) Post procedure. Arrow in C and D points to a thin aortic valve leaflet seen in both 2D and 3D long-axis views. The upper arrow in E points to significant paravalvular aortic regurgitation clearly seen beyond the confines of the prosthetic elements visualized in the 2D short-axis view. Lower arrow points to mild valvular regurgitation located within the ring. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle) (Movie clips 79.17A to D).

more contemporaneous estimates in the era of CT and echocardiography indicate the incidence to be at least 10 per 100,000.108–110 The increment is largely due to improved diagnostics and case ascertainment.111 Of the TAA, the

ascending aorta is affected in 50 to 60% of cases, the aortic arch in < 10%, and the descending thoracic aorta in 30 to 40%. The mean age of diagnosis is 59–69 years with a male predominance of 2:1 to 4:1.

1936


A

B

Figs 79.18A and B: Aortic arch aneurysm with rupture. Live/real time three-dimensional transesophageal echocardiography. (A) The top arrowhead points to the aneurysm in a 76-year-old male with a bioprosthetic aortic valve, which contains thrombus (T), and the bottom arrowhead denotes the site of rupture of this aneurysm into the mediastinum. Movie clips 79.18A Parts 1 and 2. In Movie clip 79.18A Part 2, arrowheads in the right upper panel and in the left lower panel point to en face views of the aneurysm rupture site and mouth of the aneurysm, respectively. Note the presence of spontaneous echo contrast suggestive of low blood flow state in the aneurysm and aortic arch (ACH); (B) Ascending aortic aneurysm in a 67-year-old male with rupture into the mediastinum. Arrowhead points to a large rupture visualized en face measuring 1.75 × 2.34 cm, area 3.01 cm2. It was not possible to visualize the rupture site en face by twodimensional echocardiography. Movie clip 79.18B. Source: Reproduced with permission from Joshi D, Bicer E, Donmez C, et al. Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of aortic aneurysm and dissection. Echocardiography. 2012;29:620–30.

The etiology of aneurysms can be degenerative, related to cystic medial degeneration (CMD), genetically triggered, atherosclerotic, inflammatory, traumatic, or mycotic. CMD is a common denominator in many genetically triggered TAA including Marfan syndrome (MFS). In addition, normal aging is associated with some degree of CMD and this process is accentuated by hypertension. These changes cause progressive weakening of the aortic wall, leading to dilation and aneurysm formation. The genetically triggered TAA can be syndromic with multisystem manifestations [MFS, Loeys–Dietz syndrome (LDS), vascular Ehlers–Danlos syndrome (vEDS), Turner syndrome (TS)] or nonsyndromic [familial TAA and dissection syndrome (FTAA/D), aortopathy associated with BAV] that manifests with thoracic aortic disease alone. The TAA in MFS involves the sinuses of Valsalva with the ascending aorta above the sinotubular junction usually being normal in dimension. TTE provides excellent imaging of the aortic root and the sinuses of Valsalva and is therefore an adequate imaging tool for evaluation and surveillance of TAA size in MFS. In contrast, in LDS aortic root, involvement is less common, with the descending and abdominal aorta and aortic branch vessels more frequently involved. TTE alone may, therefore, not be sufficient enough for adequate evaluation as well as surveillance

of TAA in LDS. TEE can image almost the entire thoracic aorta well and is an attractive alternative to computerized tomography or MRI. FTAA/D accounts for 20% of TAA and exhibits autosomal dominance inheritance with reduced penetrance, variable age of onset, and variable expression with regards to location of aneurysm112 with the pedigree showing TAAs in 66%, AAAs in 25%, and cerebral aneurysms in 8%. Imaging of the aorta in family members often reveals asymptomatic aneurysms, and the incidence of aortic disease increases with advancing age. BAV affects approximately 1% of the population and the aortopathy associated with BAV is one of the most common causes of ascending aortic aneurysm. The TAA associated with BAV often arises in the proximal to mid-ascending aorta, and is not a mere passive post-stenotic dilation, but a direct consequence of abnormalities of the aortic media. It may be present in absence of AS or AR and may occur late after AVR. Due to its predilection to form an aneurysm in the proximal to the mid-ascending aorta, it is imperative that the entire ascending aorta be visualized to evaluate for aneurysms above the sinotubular junction. This implies that imaging with TTE may not be optimal enough and may require evaluation with TEE or CT or MRI. The atherosclerotic TAA have predilection for the descending aorta and generally originate just distal to the origin of


1937

the left subclavian artery. Morphologically, they are either fusiform or saccular and may extend into the abdominal aorta (thoracoabdominal aneurysm) or coexist with AAA. TEE is excellent for evaluation of the atherosclerotic TAA but may need additional imaging to evaluate the distal end of the thoracoabdominal aneurysm or evaluate the presence of synchronous AAA. Many factors influence the natural history of TAA; the most robust determinants of likelihood of rupture or dissection are the underlying causes of TAA, location of TAA, pre-existing diameter of the TAA, and growth velocity. Intervention is generally recommended when the TAA reaches a certain size threshold in an appropriate candidate. In general, prophylactic surgical intervention is recommended when the ascending TAA reaches 5.5 cm, 5.0 cm in the setting of BAV, 4.5–5 cm in setting of MFS and FTAA/D, or 4 cm in LDS patients, as they are phenotypically more aggressive.113–116 In TS, prophylactic surgery has

been recommended when the ascending aorta is 3.5 cm or larger or 2.5 cm/m2 or larger.117 Other modifiers that determine the timing of intervention include the velocity of aneurysm growth > 0.5 cm/year, coexisting valvular disease and indications for concomitant cardiac surgery, and body size; surgery is recommended if the maximal cross-sectional area (in cm2) of the ascending aorta or root divided by the patient’s height in meters exceeds a ratio of 10.115 Prophylactic intervention is indicated in descending TAAs with a diameter > 5.5 cm or thoracoabdominal aortic aneurysm > 6 cm.115

A

B

C

D

Figs 79.19A to D

AORTIC DISSECTION (FIGS 79.19 TO 79.22) Although aortic dissection may occur in genetically predisposed young adults such as those with MFS, LDS, vEDS, FTAA/D, BAV, or TS, but it is mainly a disorder of the

1938


E

F

G

Figs 79.19A to G: Aortic dissection in an elderly patient. Twodimensional transthoracic and transesophageal echocardiography. (A to G) Transthoracic parasternal long-axis (A) and apical fivechamber (B) views demonstrate irregularly moving linear echoes (arrows) in the aorta (AO), resembling a wiggling worm typical of aortic dissection. Thus, in some cases, a definitive diagnosis of aortic dissection can be made by transthoracic echocardiography precluding a transesophageal study, which can subsequently be done in the operating room. This prevents undue delay in taking the patient for surgery. In this patient, the dissection flap can be clearly seen protruding into the left ventricular outflow tract in diastole and this resulted in severe aortic regurgitation. Transesophageal long(C) and short-axis (D) views of the aortic root and ascending aorta in another elderly patient show the dissection flap (arrow) extending into the right coronary artery (arrowhead). It is also seen in the vicinity of the origin of left main coronary artery (LMCA) but does not extend into it. Examination of the descending thoracic aorta in short- (E and F) and long-axis (G) views show the perfusing lumen (PL) surrounded by the nonperfusing lumen (NPL, arrow). Movie clips 79.19E shows the dissection flap mimicking opening and closing motion of a person’s mouth as if the patient was begging for help, the so-called “Help sign.” (LA: Left atrium; LV: Left ventricle; RV: Rright ventricle). (Movie clips 79.19A to E).

A

B

Figs 79.20A and B


C

D

E

F

G

H

Figs 79.20C to H

1939

1940


I elderly with ascending aortic dissection, most prevalent between 50 and 60 years of age, and descending aortic dissection peaking at 60–70 years of age. Although the classical presentation of the patient to the emergency room is severe tearing chest pain radiating to the back along with symptoms of autonomic activation, this typical presentation may be modified by the location of dissection and coexisting complications including acute coronary syndrome (ACS). Aortic dissection and ACS can present synchronously as the aortic dissection can cause impairment to coronary flow due to a variety of reasons: the dissection flap may mechanically obstruct the orifice of the left or right coronary artery, the dissection process may extend along the walls of a coronary artery significantly narrowing the vessel lumen, subadventitial hematomas (commonly present and alerts the surgeon to the presence of dissection as soon as he opens the chest wall) may compress the coronary arteries, localized pericardial effusion either due to heart failure or partial rupture of the dissected aorta into the pericardium may also compress the coronaries, and finally, hypotension resulting from dissection in an elderly patient with preexisting significant CAD may precipitate severe myocardial ischemia and/or myocardial infarction. It is important that the diagnosis of acute aortic dissection be made emergently and if it involves the ascending aorta and/or aortic arch (DeBakey type I or type II dissection or Stanford type A dissection), urgent surgical intervention is necessary. Any delay in doing this substantially increases the mortality rate, which in acute dissection is very high, up to 1–2% per hour reported in the first several hours after dissection.118 This has led to the recommendation that even a coronary arteriogram should not be performed in an elderly patient

Figs 79.20A to I: Aortic dissection rupture into the right ventricular outflow tract. (A to C) Two-dimensional transthoracic echocardiography. (A) Parasternal long-axis view. The arrowhead points to the site of rupture of the false lumen (FL) into the right ventricular outflow tract (RVOT); (B) Color Doppler examination. The arrowhead on the right points to a communication between the true lumen (TL) and FL. The arrowhead on the left shows flow signals moving from the FL to the RVOT. Moderate aortic regurgitation (AR) is also displayed; (C) Continuous wave spectral Doppler interrogation of the rupture site showing continuous flow throughout the cardiac cycle; (D to G) Live/real time three-dimensional transthoracic echocardiography; (D) The arrowhead points to the en face view of the rupture site upon cropping of the data set. It is roughly elliptical in shape and measured 0.51 cm2 in area (A) by planimetry; (E) QLab image of the same data set with the orifice (arrow head) planimeterized; (F) The arrowhead points to compression of the main pulmonary artery (PA) by the FL; (G) Extension of the dissection (arrowhead) into the left common carotid artery (LCC) is shown; (H and I) Computed tomography angiogram. (H) Left anterior oblique (LAO) view demonstrating the communication (arrowhead) between the FL and RVOT; (I) Cut slab volume rendered image in oblique LAO view demonstrating PA compression by the dilated FL. The arrow in figures H and I points to the dissection flap extending into the aortic arch and the brachiocephalic artery (BR). (A: Anterior; AO: Aaorta; F: Foot; H: Head; L: Left; LA: Left atrium; LV: Left ventricle; P: Posterior; PV: Pulmonary valve; R: Right; RA: Right atrium). (Movie clips 79.20A–I). Source: Reproduced with permission from Hansalia S, Nanda NC, et al. Live/real time three-dimensional transthoracic echocardiographic assessment of aortic dissection rupture into right ventricular outflow tract: a case report and review of literature. Echocardiography. 2009;26(1):100–6.

because that would further incur delay and catheter manipulation in the aorta may aggravate the dissection if the catheter passes into the nonperfusing lumen. It is also important to differentiate aortic dissection from an ACS to avert an immediate disastrous outcome from administration of anticoagulants or antiplatelet agents to the patient. In addition, it is paramount to be aware, as mentioned above, that both may coexist and the ACS may in fact be related to aortic dissection. CT scan is often used to detect or rule out aortic dissection because of its easy availability in the emergency room but occasionally gives false-positive results. In many centers, echo machines are also available in the emergency department and the emergency physicians are trained to perform transthoracic studies. A linear echo moving in an irregular, chaotic manner in the aortic lumen (“a worm wiggling in the aorta”) is highly specific for aortic dissection. However, a transthoracic echo may be negative in many instances and most often one has to resort to TEE to make the diagnosis. In addition to finding an irregular flap-like echo in the aortic lumen,


1941

A

B

C

Figs 79.21A to C: Aortic dissection. Transesophageal threedimensional echocardiographic reconstruction. (A and B) The descending thoracic aorta was examined using multiple cut sections and various viewing angles. Both the true (TL) and the false (FL) lumens are well visualized, and the dissection flap (F) presents as a sheet-like structure along the aortic length. The communication (arrows) between the true and false lumens is viewed en face using a transverse section in C. (H: Mediastinal hematoma that resulted from rupture of dissection). Source: Reproduced with permission from Nanda NC, Khatri G, et al. Three-dimensional echocardiographic assessment of aortic dissection. Echocardiography. 1998;15(8):745–54.

A

B

Figs 79.22A and B: Aortic dissection. Two-dimensional (A) and live/real time three-dimensional (3D) transesophageal; (B) echocardiography. Arrowhead points to a linear echo in ascending aorta (AO) consistent with dissection. However, instrument artifacts may present as linear echoes in aortic lumen mimicking dissection. Therefore, in cases where a doubt exists as to the origin of the linear echo, it is best to do a live/real time 3D study. The dissection flap will then appear as a sheet with finite width when viewed en face reflecting splitting of the aortic wall by the dissection process. Thus, aortic dissection can be confidently diagnosed or ruled out. (RPA: Right pulmonary artery) (Movie clip 79.22).

1942


differential color Doppler flow signals in the nonperfusing and perfusing lumens. and detection of a communication between the perfusing and nonperfusing lumens by color Doppler further add to the confidence level of the diagnosis. Visualization of spontaneous echo contrast signals in the vicinity of the aorta should alert one to the presence of dissection rupture and calls for immediate surgery. In these instances, rupture has occurred but has been temporarily closed by a plug of fibrin preventing exsanguination. Color Doppler is also useful in not only detecting the presence of aortic regurgitation but also assessing its severity. Severe aortic regurgitation resulting from the dissection flap interfering with aortic cusp motion and/or prolapsing into the LVOT can be diagnosed and the surgeon informed sparing the patient concomitant AV replacement. On the other hand, severe aortic regurgitation due to a dilated or distorted aorta in an elderly patient or due to thickened or retracted valve cusps found on the echocardiogram would require AV replacement. Over all, TTE has a sensitivity of 78–100% for type A aortic dissection, but only 31–55% in type B dissection; therefore, a negative TTE does not exclude acute aortic dissection. However, TEE is highly accurate for the evaluation and diagnosis of acute aortic dissection and boasts a sensitivity of >98% and specificity of 94–97%. During a transesophageal study, it is important to examine the proximal coronaries for obstruction produced by the dissection flap impinging on the orifices or narrowing produced by extension of dissection along their walls. In the older patient, coronary lumen narrowing and obstruction produced by atherosclerotic plaques can also be visualized by echocardiography and this is important information for the surgeon, especially if a preoperative coronary angiogram was not performed. Depending on the clinical status of the patient, the surgeon may consider placing bypass grafts. The perfusing lumen (which may occasionally be the false lumen) can be differentiated from the nonperfusing lumen by its expansion during systole. Also, color Doppler flow signals are usually more prominent in the perfusing lumen as compared to the nonperfusing lumen. Artifacts are not uncommonly seen in the aorta during transesophageal examination and have been mistaken for dissection in inexperienced hands with near-disastrous results. These artifacts are linear in nature and their motion tends to be parallel to the movement of the aortic walls. Also, they may extend beyond the aortic wall, which easily identifies them as artifacts and not

dissection. However, some dissections present as virtually nonmobile linear echoes and distinguishing them from an artifact becomes very difficult. In these instances, 3D TTE and TEE are invaluable in making a diagnosis with certainty. Cropping the 3D data set will demonstrate the dissection flap as a sheet of tissue that clearly differentiates it from the linearly presenting artifactual echo. Basically, aortic dissection represents “splitting” of the wall of the aorta and should, therefore, present as a tissue with finite width rather than a linear echo seen on 2D imaging, which provides only thin slice-like sections of the aorta at any given time. Dissection involving only the descending thoracic aorta (DeBakey type III or Stanford type B) may be diagnosed by 2D TTE using the suprasternal approach and by examining the descending thoracic aorta imaged behind the LV/left atrium in the parasternal long-axis view. Dissection may also be visualized in the proximal abdominal aorta using the subcostal approach. The diagnosis is made by noting echocardiographic findings similar to those mentioned above for dissection involving the ascending aorta/aortic arch. Unlike ascending aorta/aortic arch dissection, these patients are generally managed conservatively unless there is evidence of aortic enlargement and other signs of progression or there is compromise of blood supply to a visceral organ or spinal cord with impending paraplegia. In 15–20% of patients, aortic dissection does not communicate with the aortic lumen forming an IMH. This presents as a thickened aortic wall and is considered a precursor of aortic dissection. This is especially common in the hypertensive and older patient and most commonly involves the ascending aorta. Echocardiography is useful to follow its course over time and any increase in size or progression to dissection with communication with the vessel lumen warrants consideration for surgery. IMH has been found to progress to aortic dissection or rupture in up to 45%, regress completely in 34%, or evolve into pseudoaneurysm in 24%.119 Small, localized IMH are generally conservatively managed.

LEFT VENTRICULAR MASS, DIMENSIONS, AND FUNCTION LV mass increased monotonically with age in the whole Framingham study cohort, but not in a subgroup of normal individuals.120 Other studies have also corroborated that after excluding the influence of coexisting disease, LV hypertrophy is not an inevitable consequence of


aging.121,122 However, LV wall remodels with normal aging primarily with an increase in relative wall thickness (ratio of wall thickness to chamber radius) but with little or no increase in overall LV mass.123 This concentric remodeling parallels the age-related stiffening of the arterial tree, while hypertension induces concentric hypertrophy of the myocardium with an increase in LV mass. Aging induces significant alteration in LVOT geometry124 primarily due to reduction in the angle between the aorta and the interventricular septum. The age-related dilation and lengthening of the aorta may push the septum downward and kink its upper portion, accentuating the septoaortic angle. This shifts the position of the interventricular septum relative to the chest wall and leads to systematic errors in echocardiographic M-mode measurements across the LV. This anatomical alteration also induces a “septal bulge” in >10% of the geriatric population but is not associated with higher LVOT velocity or increased LV mass index. LV systolic function remains relatively well preserved and there are no significant alterations in LV ejection fraction with normal aging.125 The Doppler transmitral inflow velocities are used as surrogate indices for echocardiographic assessment of ventricular diastolic function. Both in the Framingham study126 and the Cardiovascular Health study,127 age was the predominant determinant of Doppler indices of LV diastolic function in normal subjects with decrease in peak early velocity (E-wave) and increase in peak late velocity (A-wave) with increasing age. These indices change gradually and progressively128,129 with decrement in E-wave velocity of approximately 50%126,130 together with a 40% increment of A-wave velocity between 30 and 70 years of age.131 The ratio of the peak E and A is shown to range from a mean of 2.08 ± 0.55 for subjects in their third decade to 0.84 ± 0.29 for those in their eighth decade. A peak velocity E/A ratio < 1 is abnormal in subjects aged < 40 years, but occurs in most subjects aged ≥ 70 years.126 These indices are accompanied by a prolongation of the deceleration time of the E-wave,132 and an increase in left atrial size127 and are present in more than 85% of healthy people over the age of 70 years.129 However, mitral inflow velocities profiles are affected by loading conditions,133 left atrial pressure,131 are reflective of flow patterns, and are not synonymous with function. It is therefore desirable to have additional variables to complement mitral inflow Doppler velocity in evaluating diastolic function. Pulsed wave tissue Doppler imaging (TDI) measures low amplitude myocardial velocities with a high sampling rate

1943

and can provide a measurement of the rate of change of longitudinal dimension and volume.134 The mitral annulus velocity profile by TDI during diastole consists of early diastolic movement (E′) that commences simultaneously with the onset of mitral inflow and late diastolic velocity (A′) that corresponds to the late transmitral flow A. The mitral annular TDI velocities are relatively less preloadsensitive and fall progressively with increasing age.134 In addition, significant decrement in the ratio of early to late myocardial velocities, E′/A′ with increasing age is observed mimicking the pattern of normal mitral inflow. However, although reversal of the transmitral E/A ratio occurs in the 60s, reversal of the E′ to A′ ratio occurs in the 40s.134,135

ECHOCARDIOGRAPHY IN STROKE PATIENTS: ASSESSMENT OF CORONARY STENOSIS (FIGS 79.23 TO 79.25; ALSO SEE FIG. 78.13 IN THE CHAPTER 78) Ischemic stroke constitutes 70–80% of all strokes and is caused by embolic or thrombotic occlusions of the cerebral vessels and accounts for major morbidity and mortality in the elderly.136 Embolic occlusions can be of arterial or cardiac origin, with 15–30% attributable to cardioembolism (CE). Identification of the specific etiology is crucial for risk stratification and in order to tailor the most optimal preventive strategy. CE strokes portend a poor prognosis with increased short- and long-term recurrence, higher in-hospital mortality, and a higher index of fatal recurrence versus other causes of stroke.136–138 There is no clear consensus on the indication and the optimal echocardiographic approach in the cardiac evaluation of ischemic stroke. The European Stroke Organization guidelines recommend the use of echocardiography in selected patients, while the American Stroke Association guidelines do not make any clear recommendation on its use..139,140 In real life practice, evaluation for cardiac source for embolism is one of the most common requests for the performance of a TEE (>25% of all studies at most institutions).141 TEE identifies possible sources of CE including the presence of a patent foramen ovale in >50% of patients without clinically known heart disease, in comparison, the diagnostic yield with TTE with agitated saline-injection is only 25%, which drops to 10% without saline-injection.142 However, the diagnostic superiority of TEE does not necessarily translate into altered therapeutic decisions. While the diagnosis of thrombus,

1944


A

B

C

D

Figs 79.23A to D: Ostial left main (LM) and mid-left anterior descending coronary artery (LAD) stenosis in a 72-year-old white male. Two-dimensional transesophageal echocardiography. (A) Shows an area of flow disturbance in the ostium of the LM (1), preceded by prominent flow convergence; (B) Color Doppler-guided continuous wave Doppler interrogation shows a very high diastolic velocity of 2.0 m/s (arrows) indicative of severe LM stenosis. Note also the high systolic flow velocity; (C) Demonstrates an area of aliased flow in the region of mid-LAD (2) with a high diastolic flow velocity indicating significant stenosis; (D) Coronary angiogram showing 95% ostial LM stenosis and 50% mid-LAD stenosis (arrows). (Ao: Aorta; Cx: Left circumflex coronary artery; LA: Left atrium; PA: Pulmonary artery) (Movie clip 79.23). Source: Reproduced with permission from Thakur A, Voros A, Nanda NC, et al. Transesophageal echocardiographic diagnosis of proximal coronary artery stenosis in patients with ischemic stroke. Echocardiography. 1999;16(2):159–66.

infective endocarditis, and cardiac tumors will have major therapeutic implications, entities like patent foramen ovale, atrial septal aneurysm, complex aortic atheroma, and spontaneous echo contrast may not always change patient management despite their robust epidemiological association with stroke recurrence. Although age has been used to select the echocardiographic approach in stroke patients, several studies have concluded that it should not be used as an exclusion criterion in the selection of patients for TEE.143 Presence of preexisting heart disease may

increase the probability of finding the source of CE with TTE alone and may obviate the need for TEE.122 In a study of 441 unselected ischemic stroke patients, TEE detected a source of CE in 56% of the patients. However, in the cohort of patients in sinus rhythm and without apparent heart disease, TEE altered the therapeutic strategy in only 8% of patients.144 In another study, the therapeutic impact of TEE was highest only in the cohort of patients in whom the cause of ischemic stroke remained cryptogenic despite routine diagnostics.145


A

B

C

D

E

F

Figs 79.24A to F

1945

1946


G Figs 79.24A to G: Detection of left main (LM), mid-left anterior descending coronary artery (LAD), and left internal carotid artery stenosis and demonstration of atherosclerotic plaque in the left subclavian artery in a 59-year-old black female. Two-dimensional transesophageal echocardiography. (A) The black arrowheads demonstrate prominent atherosclerotic plaques in the LM, producing 90% stenosis; (B) The arrow shows flow turbulence corresponding to the stenosis seen in A; (C) Color Doppler-guided continuous wave Doppler (arrow) demonstrates a very high diastolic flow velocity of 3 m/s consistent with severe stenosis. The systolic flow velocity is also high at 2 m/s; (D) The lower arrowheads point to a prominent shadowing effect produced by the heavily calcified plaque in the LM viewed in short axis (top arrowhead); (E) Color Doppler-guided pulsed wave Doppler interrogation of the mid-LAD (arrow) demonstrates a high peak diastolic flow velocity exceeding 1 m/s, indicating significant stenosis; (F) Withdrawal of the probe into the upper esophagus and laryngopharynx demonstrates marked narrowing of the proximal left internal carotid artery (LICA, arrow), indicative of severe stenosis; (G) The arrow shows a large soft plaque occupying 50% of the proximal left subclavian artery (LSCA) viewed in an oblique axis. (Ao: Aorta; Cx: Left circumflex coronary artery; LA: Left atrium; LCC: Left common carotid artery; LEC: Left external carotid artery; LV: Left ventricle; PA: Pulmonary artery; RVO: Right ventricular outflow tract). Source: Reproduced with permission from Thakur A, Voros A, Nanda NC, et al. Transesophageal echocardiographic diagnosis of proximal coronary artery stenosis in patients with ischemic stroke. Echocardiography. 1999;16(2):159–66.

The prevalence of asymptomatic CAD in patients with cerebrovascular disease is very high146–148 and predominantly accounts for the morbidity and mortality in patients with stroke or a transient ischemic attack (TIA).149 Although recurrent strokes occur more frequently than cardiac events over the long term after stroke, cardiac events still account for a greater proportionate mortality.150,151 It may, therefore, be pertinent to identify asymptomatic coronary artery stenosis that might benefit from specific additional therapeutic measures to prevent

a first coronary event. The American Heart Association/ American Stroke Association recommends that patients with stroke/TIA who have Framingham Risk Scorepredicted 10-year CHD risk ≥ 20% should be considered for noninvasive testing for asymptomatic CAD.149 TEE evaluation of stroke patients provides a unique opportunity in which the presence of coexisting disease of a major epicardial artery can be evaluated.152 Direct visualization of the origins of the left and right coronary arteries is possible in the transverse imaging plane, basal short-axis view, just above AV leaflets. With anteflexion and slight leftward tilting, the left main ostium and the entire length of the left main coronary artery can be imaged between the 1 and 2 o’clock positions. Continued tracking allows visualization until the left anterior descending (LAD) and left circumflex coronary arteries bifurcate. Further inferior tilting or slight probe angulation allows longer segments of the LAD to be visualized. The ostium of the right coronary artery (RCA) can be imaged in the basal short-axis, transverse image plane, and interrogating between the 6 and 7 o’clock positions.153 Coronary stenosis can be diagnosed by Doppler interrogation of the diastolic flow in the coronary arteries. The TEE pulsed wave Doppler waveform in the normal LAD generally consists of a peak velocity of 40 ± 20 cm/s,154 which is fairly consistent with normal maximal diastolic velocity of 49 ± 20 cm/s and 37 ± 12 cm/s in the LAD and RCA, respectively.155 In patients with significant coronary stenosis, pulsed wave Doppler velocities are significantly increased to >100 cm/s, and the color-flow pattern changes from a low-velocity, laminar pattern to the characteristic mosaic color flow pattern seen with turbulent flow and higher velocities that exceed the Nyquist limit. However, patients with elevated cardiac output, moderate to severe aortic regurgitation, or hypertrophic obstructive cardiomyopathy normally have augmented coronary artery velocities exceeding 100 cm/s.156,157 Conversely, extremely severe luminal narrowing (subtotal or highgrade stenosis) may limit coronary flow so severely that the velocity within the vessel is actually diminished.

MITRAL ANNULAR CALCIFICATION (FIG. 79.7; ALSO SEE FIG. 70.58 IN THE CHAPTER 70) Mitral annular calcification (MAC) is a chronic degenerative process of the mitral valve ring that was first described in 1908 by Bonninger as associated with


A

1947

B

C

D

E

Figs 79.25A to E: Anomalous coronary artery in a 69-year-old black female. Two-dimensional transesophageal echocardiography. The patient presented with pulmonary edema and stroke with left sided residual weakness. (A and B) Show both, left main (right arrowhead) and right coronary arteries (left arrowhead) with color flow in B, arising from a common ostium in the right sinus with the left main coursing between aorta (AO) and right ventricular outflow tract (RVO); (C) The arrowhead points to intramyocardial course of the left anterior descending coronary artery (arrowhead) within the ventricular septum; (D) Demonstrates the course of right coronary artery (arrowhead) in the right atrioventricular groove; (E) Coronary angiogram showing the common origin of the left main (LM) and right coronary (RCA) arteries. The patient underwent percutaneous transluminal coronary angioplasty with stent placement in mid RCA because of 90% stenosis. (Movie clip 79.25) (LVO: Left ventricular outflow tract; MV: Mitral valve; RV: Right ventricle). Source: Reproduced with permission from Nanda NC, Bhambore M, Jindal A, et al. Transesophageal Three-Dimensional Echocardiographic Assessment of Anomalous Coronary Arteries. Echocardiography. 2000;17(1):53–60.

1948


complete heart block.158 In the cardiovascular health study, MAC was found in 42% of patients with a mean age of 76 years.159 In the Atherosclerotic Risk in Communities (ARIC) study,160 MAC was much less common in younger subjects with a mean age of 59 and a prevalence of 4.6% in females and 5.6% in males. The calcific process in MAC initiates at the attachment points of the annulus and the calcification may extend to involve the base and body of both mitral leaflets. Mitral regurgitation (MR) is commonly associated with MAC, with a reported incidence of up to 63%.161 The putative mechanism for MR is accentuated rigidity of the annulus. Typically, MR is mild to moderate by color Doppler and not severe enough to require surgical intervention. However, severe annular calcification may result in poor penetration of the ultrasonic beam resulting in underestimation of the severity of mitral regurgitation. In these cases, it is important to perform a 3D transthoracic study to assess the regurgitant vena contracta, which can provide a more quantitative estimate of the severity of mitral regurgitation. Transesophageal echo may also need to be done in difficult cases. Typically, leaflet tips are spared and this distinguishes it from rheumatic mitral disease, where calcification commonly involves the tips of mitral leaflets and commissures producing a typical “hockey stick” appearance. In the elderly, calcification may occur in the chordae and papillary muscles but, unlike rheumatic disease, does not produce chordal shortening and fusion. MAC in the elderly may occasionally become severe enough to produce significant mitral stenosis requiring mitral valve replacement. Calcification may also involve the aortic annulus and rarely the tricuspid annulus where fatty deposits are more common. The latter may mimic a tumor mass. Occasionally, calcification may involve the whole cardiac skeleton as well as the proximal ventricular walls in the elderly, resulting in various types of heart block and other conduction abnormalities. 2D TTE represents the best noninvasive technique to not only diagnose but also assess the extent and severity of mitral annulus calcification as well as calcification affecting other areas of the heart. The diagnosis is made by noting the presence of highly echogenic areas in and surrounding the mitral annulus best seen in the parasternal and apical planes. A short-axis view at the level of the mitral valve may show crescent-shaped calcification posteriorly similar to fluoroscopy and chest X-ray. One particular abnormality one has to be particularly aware of in the elderly is caseous calcification. With the passage of time, a severely calcified area of the mitral annulus may undergo liquefaction

simulating tumor necrosis and may show some mobility. This is essentially a benign condition and does not need any surgical intervention. However, some of these patients have been referred for surgical resection in the mistaken belief that the lesion is an annular tumor. We have found live/real time 3D TTE useful in these cases to make a more confident diagnosis of caseous calcification.162 Careful cropping of the 3D data set shows the extent and severity of echolucencies and in one particular elderly patient studied by us intraoperatively, a typical telltale tooth paste– like appearance was noted when the mass was sectioned and viewed en face on the 3D data set. This finding was confirmed at surgery. MAC is associated with traditional CV risk factors and calcific aortic disease, coronary atherosclerosis and chronic kidney disease, and is now considered the surrogate marker of atherosclerosis. Several trials have evaluated the association between MAC and CV outcomes. Data from the Framingham study suggested that each 1-mm increment in MAC increased the composite risk of CVD, CVD death, and all-cause death by approximately 10%.163 Similarly, MAC was found to incur a significant risk for coronary events in the ARIC study160 and increased CV morbidity, CV mortality, and all-cause mortality of patients with atrial fibrillation in the Belgrade Atrial Fibrillation Study.164

PROSTHETIC VALVES (FIGS 79.26 AND 79.27) Prosthetic valves are common in geriatric population. A suggested estimate of the prevalence of valve prostheses ranged from 0.2 per 1,000 in those aged 44 and under to 5.3 per 1,000 in those 75 years of age and older.165 3D TTE has been shown to be superior to 2D TTE in the evaluation of prosthetic valves, especially the mechanical prostheses, since it allows for the visualization of both leaflets simultaneously, which increases the confidence in excluding significant abnormalities.166 Although the current guidelines continue to be based on the unreliable Doppler-derived pressure gradients for the assessment of prosthetic valve dysfunction, 3D TTE is emerging as a more robust tool.167,168 In conclusion, echo/Doppler techniques represent the most useful and most cost-effective noninvasive modalities in the assessment of CV disease entities in the geriatric patient. In addition, these techniques are also useful in monitoring various structural and physiological changes that occur in the CV system with aging.


1949

A

B

C

Figs 79.26A to C: St. Jude mitral prosthesis in a 70-year-old female. Live/real time three-dimensional transthoracic echocardiography. (A) Arrow points to a large thrombus on the atrial aspect of mitral valve replacement (MVR); (B) Arrows point to two thrombi on the ventricular aspect; (C) Arrow points to a thrombus in the left atrial appendage (LAA; Movie clips 79.26 Parts 1 to 3). The arrowheads in Part 1 show thrombi on the atrial aspect of the prosthesis. The arrowhead in Part 2 denotes an irregular thrombus with some mobility in the left atrial appendage. Part 3 of the movie clip shows virtually no motion of the prosthetic valve, only ring motion. (AO: aorta; LA: Left atrium; LV: Left ventricle; R: Reverberations from MVR; RV: Right ventricle). Source: Reproduced with permission from Singh P, Inamdar V, Hage FG, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in evaluation of prosthetic valve function. Echocardiography. 2009;26:1236–49.

Fig. 79.27: Tissue mitral prosthesis in a 85-year-old female patient. Live/real time three-dimensional transthoracic echocardiography. Arrow points to a tear in one of the leaflets of mitral valve replacement (MVR) that is prolapsing into left atrium (LA; Movie clips 79.27 Parts 1 to 3). (AV: Aortic valve). Other abbreviations as in previous figure. Source: Reproduced with permission from Singh P, Inamdar V, Hage FG, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in evaluation of prosthetic valve function. Echocardiography. 2009;26:1236–49.

1950


REFERENCES 1. Tunick PA, Rosenzweig BP, Katz ES, et al. High risk for vascular events in patients with protruding aortic atheromas: a prospective study. J Am Coll Cardiol. 1994; 23(5):1085–90. 2. Meissner I, Khandheria BK, Sheps SG, et al. Atherosclerosis of the aorta: risk factor, risk marker, or innocent bystander? A prospective population-based transesophageal echocardiography study. J Am Coll Cardiol. 2004;44(5):1018–24. 3. Jones EF, Kalman JM, Calafiore P, et al. Proximal aortic atheroma. An independent risk factor for cerebral ischemia. Stroke. 1995;26(2):218–24. 4. Amarenco P, Cohen A, Tzourio C, et al. Atherosclerotic disease of the aortic arch and the risk of ischemic stroke. N Engl J Med. 1994;331(22):1474–9. 5. Katz ES, Konecky N, Tunick PA, et al. Visualization and identification of the left common carotid and left subclavian arteries: a transesophageal echocardiographic approach. J Am Soc Echocardiogr. 1996;9(1):58–61. 6. Zaidat OO, Suarez JI, Hedrick D, et al. Reproducibility of transesophageal echocardiography in evaluating aortic atheroma in stroke patients. Echocardiography. 2005;22(4): 326–30. 7. Sundt TM. Intramural hematoma and penetrating atherosclerotic ulcer of the aorta. Ann Thorac Surg. 2007;83(2): S835–41; discussion S846. 8. Cho KR, Stanson AW, Potter DD, et al. Penetrating atherosclerotic ulcer of the descending thoracic aorta and arch. J Thorac Cardiovasc Surg. 2004;127(5):1393–9; discussion 1399. 9. Demers P, Miller DC, Mitchell RS, et al. Stent-graft repair of penetrating atherosclerotic ulcers in the descending thoracic aorta: mid-term results. Ann Thorac Surg. 2004; 77(1):81–6. 10. Eggebrecht H, Baumgart D, Schmermund A, et al. Endovascular stent-graft repair for penetrating atherosclerotic ulcer of the descending aorta. Am J Cardiol. 2003;91(9): 1150–3. 11. Sailer J, Peloschek P, Rand T, et al. Endovascular treatment of aortic type B dissection and penetrating ulcer using commercially available stent-grafts. AJR Am J Roentgenol. 2001;177(6):1365–9. 12. Schoder M, Grabenwöger M, Hölzenbein T, et al. Endovascular stent-graft repair of complicated penetrating atherosclerotic ulcers of the descending thoracic aorta. J Vasc Surg. 2002;36(4):720–6. 13. Pitton MB, Duber C, Neufang A, et al. Endovascular repair of a non-contained aortic rupture caused by a penetrating aortic ulcer. Cardiovasc Intervent Radiol. 2002;25(1):64–7. 14. Bruns DL, Van Der Hauwaert LG. The aortic systolic murmur developing with increasing age. Br Heart J. 1958;20 (3):370–8. 15. Bethel CS, Crow EW. Heart sounds in the aged. Am J Cardiol. 1963;11:763–7. 16. Jaffe WM, Roche AH, Coverdale HA, et al. Clinical evaluation versus Doppler echocardiography in the quantitative assessment of valvular heart disease. Circulation. 1988;78 (2):267–75.

17. McKillop GM, Stewart DA, Burns JM, et al. Doppler echocardiography in elderly patients with ejection systolic murmurs. Postgrad Med J. 1991;67(794):1059–61. 18. Bonow RO, Carabello BA, Chatterjee K, et al. 2006 Writing Committee Members; American College of Cardiology/ American Heart Association Task Force. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients with Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2008;118(15):e523–661. 19. Prasad Y, Bhalodkar NC. Aortic sclerosis–a marker of coronary atherosclerosis. Clin Cardiol. 2004;27(12):671–3. 20. Stewart BF, Siscovick D, Lind BK, et al. Clinical factors associated with calcific aortic valve disease. Cardiovascular Health Study. J Am Coll Cardiol. 1997;29(3):630–4. 21. Lindroos M, Kupari M, Heikkilä J, et al. Prevalence of aortic valve abnormalities in the elderly: an echocardiographic study of a random population sample. J Am Coll Cardiol. 1993;21(5):1220–5. 22. Pomerance A, Darby AJ, Hodkinson HM. Valvular calcification in the elderly: possible pathogenic factors. J Gerontol. 1978;33(5):672–5. 23. Otto CM, Lind BK, Kitzman DW, et al. Association of aorticvalve sclerosis with cardiovascular mortality and morbidity in the elderly. N Engl J Med. 1999;341(3):142–7. 24. Aronow WS, Ahn C, Schoenfeld MR, et al. Association of extracranial carotid arterial disease and chronic atrial fibrillation with the incidence of new thromboembolic stroke in 1,846 older persons. Am J Cardiol. 1999;83(9): 1403–4, A8. 25. Olsen MH, Wachtell K, Bella JN, et al. Effect of losartan versus atenolol on aortic valve sclerosis (a LIFE substudy). Am J Cardiol. 2004;94(8):1076–80. 26. Chandra HR, Goldstein JA, Choudhary N, et al. Adverse outcome in aortic sclerosis is associated with coronary artery disease and inflammation. J Am Coll Cardiol. 2004; 43(2):169–75. 27. Cosmi JE, Kort S, Tunick PA, et al. The risk of the development of aortic stenosis in patients with “benign” aortic valve thickening. Arch Intern Med. 2002;162(20):2345–7. 28. Faggiano P, Antonini-Canterin F, Erlicher A, et al. Progression of aortic valve sclerosis to aortic stenosis. Am J Cardiol. 2003;91(1):99–101. 29. O’Brien KD. Pathogenesis of calcific aortic valve disease: a disease process comes of age (and a good deal more). Arterioscler Thromb Vasc Biol. 2006;26(8):1721–8. 30. Roberts WC, Ko JM. Frequency by decades of unicuspid, bicuspid, and tricuspid aortic valves in adults having isolated aortic valve replacement for aortic stenosis, with or without associated aortic regurgitation. Circulation. 2005;111(7):920–5.


31. Dare AJ, Veinot JP, Edwards WD, et al. New observations on the etiology of aortic valve disease: a surgical pathologic study of 236 cases from 1990. Hum Pathol. 1993;24(12): 1330–8. 32. Stephan PJ, Henry AC 3rd, Hebeler RF Jr, et al. Comparison of age, gender, number of aortic valve cusps, concomitant coronary artery bypass grafting, and magnitude of left ventricular-systemic arterial peak systolic gradient in adults having aortic valve replacement for isolated aortic valve stenosis. Am J Cardiol. 1997;79(2):166–72. 33. Roberts WC, Ko JM, Matter GJ. Aortic valve replacement for aortic stenosis in nonagenarians. Am J Cardiol. 2006; 98(9):1251–3. 34. Rajamannan NM, Bonow RO, Rahimtoola SH. Calcific aortic stenosis: an update. Nat Clin Pract Cardiovasc Med. 2007;4(5):254–62. 35. Aronow WS. Valvular aortic stenosis in the elderly. Cardiol Rev. 2007;15(5):217–25. 36. Omran H, Schmidt H, Hackenbroch M, et al. Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study. Lancet. 2003;361(9365):1241–6. 37. Gorlin R, Gorlin SG. Hydraulic formula for calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. I. Am Heart J. 1951;41(1):1–29. 38. Switzer DF, Nanda NC. Doppler color flow mapping. Ultrasound Med Biol. 1985;11(3):403–16. 39. Eddleman EE Jr, Frommeyer WB Jr, Lyle DP, et al. Critical analysis of clinical factors in estimating severity of aortic valve disease. Am J Cardiol. 1973;31(6):687–95. 40. Nanda NC. Textbook of Color Doppler Echocardiography. Philadelphia, PA: Lea and Febiger, Inc; 1989:178–90. 41. de Monchy CC, Lepage L, Boutron I, et al. Usefulness of the right parasternal view and non-imaging continuouswave Doppler transducer for the evaluation of the severity of aortic stenosis in the modern area. Eur J Echocardiogr. 2009;10(3):420–4. 42. Otto CM. Valvular aortic stenosis: disease severity and timing of intervention. J Am Coll Cardiol. 2006;47(11): 2141–51. 43. Oh JK, Taliercio CP, Holmes DR Jr, et al. Prediction of the severity of aortic stenosis by Doppler aortic valve area determination: prospective Doppler-catheterization correlation in 100 patients. J Am Coll Cardiol. 1988;11(6): 1227–34. 44. Zoghbi WA, Farmer KL, Soto JG, et al. Accurate noninvasive quantification of stenotic aortic valve area by Doppler echocardiography. Circulation. 1986;73(3):452–9. 45. Grayburn PA, Smith MD, Harrison MR, et al. Pivotal role of aortic valve area calculation by the continuity equation for Doppler assessment of aortic stenosis in patients with combined aortic stenosis and regurgitation. Am J Cardiol. 1988;61(4):376–81. 46. Doddamani S, Grushko MJ, Makaryus AN, et al. Demonstration of left ventricular outflow tract eccentricity by 64-slice multi-detector CT. Int J Cardiovasc Imaging. 2009; 25(2):175–81.

1951

47. Swinne CJ, Shapiro EP, Jamart J, et al. Age-associated changes in left ventricular outflow tract geometry in normal subjects. Am J Cardiol. 1996;78(9):1070–3. 48. Baumgartner H, Stefenelli T, Niederberger J, et al. “Overestimation” of catheter gradients by Doppler ultrasound in patients with aortic stenosis: a predictable manifestation of pressure recovery. J Am Coll Cardiol. 1999;33 (6):1655–61. 49. Laskey WK, Kussmaul WG. Pressure recovery in aortic valve stenosis. Circulation. 1994;89(1):116–21. 50. Levine RA, Jimoh A, Cape EG, et al. Pressure recovery distal to a stenosis: potential cause of gradient “overestimation” by Doppler echocardiography. J Am Coll Cardiol. 1989; 13(3):706–15. 51. Garcia D, Dumesnil JG, Durand LG, et al. Discrepancies between catheter and Doppler estimates of valve effective orifice area can be predicted from the pressure recovery phenomenon: practical implications with regard to quantification of aortic stenosis severity. J Am Coll Cardiol. 2003;41(3):435–42. 52. Vengala S, Nanda NC, Dod HS, et al. Images in geriatric cardiology. Usefulness of live three-dimensional transthoracic echocardiography in aortic valve stenosis evaluation. Am J Geriatr Cardiol. 2004;13(5):279–84. 53. Bernard Y, Meneveau N, Vuillemenot A , et al. Planimetry of aortic valve area using multiplane transoesophageal echocardiography is not a reliable method for assessing severity of aortic stenosis. Heart. 1997;78(1):68–73. 54. Gilon D, Cape EG, Handschumacher MD, et al. Effect of three-dimensional valve shape on the hemodynamics of aortic stenosis: three-dimensional echocardiographic stereolithography and patient studies. J Am Coll Cardiol. 2002;40(8):1479–86. 55. Donal E, Novaro GM, Deserrano D, et al. Planimetric assessment of anatomic valve area overestimates effective orifice area in bicuspid aortic stenosis. J Am Soc Echocardiogr. 2005;181:1392–8. 56. Cormier B, Iung B, Porte JM, et al. Value of multiplane transesophageal echocardiography in determining aortic valve area in aortic stenosis. Am J Cardiol. 1996;77(10): 882–5. 57. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012): the Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2012;33:2451–96. 58. Connolly HM, Oh JK, Schaff HV, et al. Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients. Circulation. 2000;101(16):1940–6. 59. deFilippi CR, Willett DL, Brickner ME, et al. Usefulness of dobutamine echocardiography in distinguishing severe from nonsevere valvular aortic stenosis in patients with depressed left ventricular function and low transvalvular gradients. Am J Cardiol. 1995;75(2):191–4.

1952


60. Schwammenthal E, Vered Z, Moshkowitz Y, et al. Dobutamine echocardiography in patients with aortic stenosis and left ventricular dysfunction: predicting outcome as a function of management strategy. Chest. 2001; 119(6):1766–77. 61. Monin JL, Quéré JP, Monchi M, et al. Low-gradient aortic stenosis: operative risk stratification and predictors for long-term outcome: a multicenter study using dobutamine stress hemodynamics. Circulation. 2003;108(3):319–24. 62. Clavel MA, Fuchs C, Burwash IG, et al. Predictors of outcomes in low-flow, low-gradient aortic stenosis: results of the multicenter TOPAS Study. Circulation. 2008;118 (14 Suppl):S234–42. 63. Levy F, Laurent M, Monin JL, et al. Aortic valve replacement for low-flow/low-gradient aortic stenosis operative risk stratification and long-term outcome: a European multicenter study. J Am Coll Cardiol. 2008;51(15):1466–72. 64. Awtry E, Davidoff R. Low-flow/low-gradient aortic stenosis. Circulation. 2011;124(23):e739–41. 65. Baumgartner H, Hung J, Bermejo J, et al. EAE/ASE. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. Eur J Echocardiogr. 2009;10(1):1–25. 66. Tribouilloy C, Lévy F, Rusinaru D, et al. Outcome after aortic valve replacement for low-flow/low-gradient aortic stenosis without contractile reserve on dobutamine stress echocardiography. J Am Coll Cardiol. 2009;53(20):1865–73. 67. Blais C, Burwash IG, Mundigler G, et al. Projected valve area at normal flow rate improves the assessment of stenosis severity in patients with low-flow, low-gradient aortic stenosis: the multicenter TOPAS (Truly or Pseudo-Severe Aortic Stenosis) study. Circulation. 2006;113(5):711–21. 68. Clavel MA, Burwash IG, Mundigler G, et al. Validation of conventional and simplified methods to calculate projected valve area at normal flow rate in patients with low flow, low gradient aortic stenosis: the multicenter TOPAS (True or Pseudo Severe Aortic Stenosis) study. J Am Soc Echocardiogr. 2010;23(4):380–6. 69. Nishimura RA, Grantham JA, Connolly HM, et al. Lowoutput, low-gradient aortic stenosis in patients with depressed left ventricular systolic function: the clinical utility of the dobutamine challenge in the catheterization laboratory. Circulation. 2002;106(7):809–13. 70. Bergler-Klein J, Mundigler G, Pibarot P, et al. B-type natriuretic peptide in low-flow, low-gradient aortic stenosis: relationship to hemodynamics and clinical outcome: results from the Multicenter Truly or Pseudo-Severe Aortic Stenosis (TOPAS) study. Circulation. 2007;115(22):2848–55. 71. Gotzmann M, Lindstaedt M, Bojara W, et al. Clinical outcome of transcatheter aortic valve implantation in patients with low-flow, low gradient aortic stenosis. Catheter Cardiovasc Interv. 2012;79(5):693–701. 72. Hachicha Z, Dumesnil JG, Bogaty P, et al. Paradoxical lowflow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival. Circulation. 2007;115(22):2856–64.

73. Clavel MA, Dumesnil JG, Capoulade R, et al. Outcome of patients with aortic stenosis, small valve area, and low-flow, low-gradient despite preserved left ventricular ejection fraction. J Am Coll Cardiol. 2012;60(14):1259–67. 74. Cramariuc D, Cioffi G, Rieck AE, et al. Low-flow aortic stenosis in asymptomatic patients: valvular-arterial impedance and systolic function from the SEAS Substudy. JACC Cardiovasc Imaging. 2009;2(4):390–9. 75. Herrmann S, Störk S, Niemann M, et al. Low-gradient aortic valve stenosis myocardial fibrosis and its influence on function and outcome. J Am Coll Cardiol. 2011;58(4): 402–12. 76. Adda J, Mielot C, Giorgi R, et al. Low-flow, low-gradient severe aortic stenosis despite normal ejection fraction is associated with severe left ventricular dysfunction as assessed by speckle-tracking echocardiography: a multicenter study. Circ Cardiovasc Imaging. 2012;5(1):27–35. 77. Weidemann F, Herrmann S, Störk S, et al. Impact of myocardial fibrosis in patients with symptomatic severe aortic stenosis. Circulation. 2009;120(7):577–84. 78. Nanda NC, Hsuing MC, Miller AP, et al. Live/Real 3D Echoardiography. Willey Blackwell. August 2010. 79. Hage FG, Nanda NC. Real-time three-dimensional echocardiography: a current view of what echocardiography can provide? Indian Heart J. 2009;61(2):146–55. 80. Nanda NC, Roychoudhury D, Chung SM, et al. Quantitative assessment of normal and stenotic aortic valve using transesophageal three-dimensional echocardiography. Echocardiography. 1994;11(6):617–25. 81. Nanda NC, Sorrell VL. Atlas of Three-Dimensional Echocardiography. Armonk, NY: Futura Publishing Co; 2002:49. 82. Kasprzak JD, Nosir YF, Dall’Agata A, et al. Quantification of the aortic valve area in three-dimensional echocardiographic data sets: analysis of orifice overestimation resulting from suboptimal cut-plane selection. Am Heart J. 1998;135(6 Pt 1):995–1003. 83. Vengala S, Nanda NC, Dod HS, et al. Images in geriatric cardiology. Usefulness of live three-dimensional transthoracic echocardiography in aortic valve stenosis evaluation. Am J Geriatr Cardiol. 2004;13(5):279–84. 84. Agrawal GG, Nanda NC, Htay T, et al. Live three-dimensional transthoracic echocardiographic identification of discrete subaortic membranous stenosis. Echocardiography. 2003; 20(7):617–19. 85. Bandarupalli N, Faulkner M, Nanda NC, et al. Erroneous diagnosis of significant obstruction by Doppler in a patient with discrete subaortic membrane: correct diagnosis by 3D-transthoracic echocardiography. Echocardiography. 2008;25(9):1004–6. 86. Rajdev S, Nanda NC, Patel V, et al. Live/real-time threedimensional transthoracic echocardiographic assessment of combined valvar and supravalvar aortic stenosis. Am J Geriatr Cardiol. 2006;15(3):188–90. 87. Gaasch WH. Left ventricular radius to wall thickness ratio. Am J Cardiol. 1979;43(6):1189–94.


88. Bache RJ, Vrobel TR, Ring WS, et al. Regional myocardial blood flow during exercise in dogs with chronic left ventricular hypertrophy. Circ Res. 1981;48(1):76–87. 89. Marcus ML, Doty DB, Hiratzka LF, et al. Decreased coronary reserve: a mechanism for angina pectoris in patients with aortic stenosis and normal coronary arteries. N Engl J Med. 1982;307(22):1362–6. 90. Gaasch WH, Zile MR, Hoshino PK, et al. Tolerance of the hypertrophic heart to ischemia. Studies in compensated and failing dog hearts with pressure overload hypertrophy. Circulation. 1990;81(5):1644–53. 91. Koyanagi S, Eastham CL, Harrison DG, et al. Increased size of myocardial infarction in dogs with chronic hypertension and left ventricular hypertrophy. Circ Res. 1982;50(1): 55–62. 92. Aurigemma GP, Silver KH, McLaughlin M, et al. Impact of chamber geometry and gender on left ventricular systolic function in patients > 60 years of age with aortic stenosis. Am J Cardiol. 1994;74(8):794–8. 93. Carroll JD, Carroll EP, Feldman T, et al. Sex-associated differences in left ventricular function in aortic stenosis of the elderly. Circulation. 1992;86(4):1099–107. 94. Orsinelli DA, Aurigemma GP, Battista S, et al. Left ventricular hypertrophy and mortality after aortic valve replacement for aortic stenosis. A high risk subgroup identified by preoperative relative wall thickness. J Am Coll Cardiol. 1993;22(6):1679–83. 95. Briand M, Dumesnil JG, Kadem L, et al. Reduced systemic arterial compliance impacts significantly on left ventricular afterload and function in aortic stenosis: implications for diagnosis and treatment. J Am Coll Cardiol. 2005;46(2): 291–8. 96. Kadem L, Dumesnil JG, Rieu R, et al. Impact of systemic hypertension on the assessment of aortic stenosis. Heart. 2005;91(3):354–61. 97. Leon MB, Smith CR, Mack M, et al. Transcatheter aorticvalve implantation for aortic stenosis in patients who cannot undergosurgery. N Engl J Med. 2011;363:1597–607. 98. Smith CR, Leon MB, Mack MJ, et al.; PARTNER Trial Investigators. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364 (23):2187–98. 99. Détaint D, Lepage L, Himbert D, et al. Determinants of significant paravalvular regurgitation after transcatheter aortic valve: implantation impact of device and annulus discongruence. JACC Cardiovasc Interv. 2009;2(9):821–7. 100. Rajani R, Kakad M, Khawaja MZ, et al. Paravalvular regurgitation one year after transcatheter aortic valve implantation. Catheter Cardiovasc Interv. 2010;75(6):868–72. 101. Abdel-Wahab M, Zahn R, Horack M, et al.; German transcatheter aortic valve interventions registry investigators. Aortic regurgitation after transcatheter aortic valve implantation: incidence and early outcome. Results from the German transcatheter aortic valve interventions registry. Heart. 2011;97(11):899–906. 102. Doddamani S, Grushko MJ, Makaryus AN, et al. Demonstration of left ventricular outflow tract eccentricity by 64-slice multi-detector CT. Int J Cardiovasc Imaging. 2009; 25(2):175–81.

1953

103. Doddamani S, Bello R, Friedman MA, et al. Demonstration of left ventricular outflow tract eccentricity by real time 3D echocardiography: implications for the determination of aortic valve area. Echocardiography. 2007;24(8):860–6. 104. Messika-Zeitoun D, Serfaty JM, Brochet E, et al. Multimodal assessment of the aortic annulus diameter: implications for transcatheter aortic valve implantation. J Am Coll Cardiol. 2010;55(3):186–94. 105. Otani K, Takeuchi M, Kaku K, et al. Assessment of the aortic root using real-time 3D transesophageal echocardiography. Circ J. 2010;74(12):2649–57. 106. Kempfert J, Van LInden A, Lehmkuhl L, et al. Aortic annulus sizing: Echocardiographic versus CT derived measurements in comparison with direct aortic sizing. European J Cardio-Thoracic Surgery. 2012;1–7. 107. Bickerstaff LK, Pairolero PC, Hollier LH, et al. Thoracic aortic aneurysms: a population-based study. Surgery. 1982; 92(6):1103–8. 108. Ramanath VS, Oh JK, Sundt TM 3rd, et al. Acute aortic syndromes and thoracic aortic aneurysm. Mayo Clin Proc. 2009;84(5):465–81. 109. Clouse WD, Hallett JW Jr, Schaff HV, et al. Improved prognosis of thoracic aortic aneurysms: a population-based study. JAMA. 1998;280(22):1926–9. 110. Olsson C, Thelin S, Ståhle E, et al. Thoracic aortic aneurysm and dissection: increasing prevalence and improved outcomes reported in a nationwide population-based study of more than 14,000 cases from 1987 to 2002. Circulation. 2006;114(24):2611–18. 111. Wittram C, Meehan MJ, Halpern EF, et al. Trends in thoracic radiology over a decade at a large academic medical center. J Thorac Imaging. 2004;19(3):164–70. 112. Albornoz G, Coady MA, Roberts M, et al. Familial thoracic aortic aneurysms and dissections–incidence, modes of inheritance, and phenotypic patterns. Ann Thorac Surg. 2006;82(4):1400–5. 113. Elefteriades JA, Farkas EA. Thoracic aortic aneurysm clinically pertinent controversies and uncertainties. J Am Coll Cardiol. 2010;55(9):841–57. 114. Davies RR, Kaple RK, Mandapati D, et al. Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve. Ann Thorac Surg. 2007;83(4):1338–44. 115. Hiratzka LF, Bakris GL, Beckman JA, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines; American Association for Thoracic Surgery; American College of Radiology; American Stroke Association; Society of Cardiovascular Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society of Interventional Radiology; Society of Thoracic Surgeons; Society for Vascular Medicine. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/ SIR/STS/SVM guidelines for the diagnosis and management of patients with Thoracic Aortic Disease: a report of the American College of Cardiology Foundation/ American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions,

1954

116.

117. 118.

119.

120.

121.

122.

123.

124.

125.

126.

127.

128.

129.

130. 131.


Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Circulation. 2010;121(13):e266–369. Williams JA, Loeys BL, Nwakanma LU, et al. Early surgical experience with Loeys-Dietz: a new syndrome of aggressive thoracic aortic aneurysm disease. Ann Thorac Surg. 2007;83(2):S757–63; discussion S785. Bondy CA. Aortic dissection in Turner syndrome. Curr Opin Cardiol. 2008;23(6):519–26. Hirst AE Jr, Johns VJ Jr, Kime SW Jr. Dissecting aneurysm of the aorta: a review of 505 cases. Medicine (Baltimore). 1958;37(3):217–79. Ramanath VS, Oh JK, Sundt TM 3rd, et al. Acute aortic syndromes and thoracic aortic aneurysm. Mayo Clin Proc. 2009;84(5):465–81. Dannenberg AL, Levy D, Garrison RJ. Impact of age on echocardiographic left ventricular mass in a healthy population (the Framingham Study). Am J Cardiol. 1989;64(16): 1066–8. Kitzman DW, Scholz DG, Hagen PT, et al. Age-related changes in normal human hearts during the first 10 decades of life. Part II (Maturity): A quantitative anatomic study of 765 specimens from subjects 20 to 99 years old. Mayo Clin Proc. 1988;63(2):137–46. Olivetti G, Melissari M, Capasso JM, et al. Cardiomyopathy of the aging human heart. Myocyte loss and reactive cellular hypertrophy. Circ Res. 1991;68(6):1560–8. Ganau A, Saba PS, Roman MJ, et al. Ageing induces left ventricular concentric remodelling in normotensive subjects. J Hypertens. 1995;13(12 Pt 2):1818–22. Swinne CJ, Shapiro EP, Jamart J, et al. Age-associated changes in left ventricular outflow tract geometry in normal subjects. Am J Cardiol. 1996;78(9):1070–3. Wandt B, Bojö L, Hatle L, et al. Left ventricular contraction pattern changes with age in normal adults. J Am Soc Echocardiogr. 1998;11(9):857–63. Benjamin EJ, Levy D, Anderson KM, et al. Determinants of Doppler indexes of left ventricular diastolic function in normal subjects (the Framingham Heart Study). Am J Cardiol. 1992;70(4):508–15. Gardin JM, Arnold AM, Bild DE, et al. Left ventricular diastolic filling in the elderly: the cardiovascular health study. Am J Cardiol. 1998;82(3):345–51. Schirmer H, Lunde P, Rasmussen K. Mitral flow derived Doppler indices of left ventricular diastolic function in a general population; the Tromso study. Eur Heart J. 2000;21(16):1376–86. Sagie A, Benjamin EJ, Galderisi M, et al. Reference values for Doppler indexes of left ventricular diastolic filling in the elderly. J Am Soc Echocardiogr. 1993;6(6):570–6. Wei JY. Age and the cardiovascular system. N Engl J Med. 1992;327(24):1735–9. Kuo LC, Quinones MA, Rokey R, et al. Quantification of atrial contribution to left ventricular filling by pulsed Doppler echocardiography and the effect of age in normal and diseased hearts. Am J Cardiol. 1987;59(12):1174–8.

132. Pearson AC, Gudipati C, Nagelhout D, et al. Echocardiographic evaluation of cardiac structure and function in elderly subjects with isolated systolic hypertension. J Am Coll Cardiol. 1991;17(2):422–30. 133. Choong CY, Herrmann HC, Weyman AE, et al. Preload dependence of Doppler-derived indexes of left ventricular diastolic function in humans. J Am Coll Cardiol. 1987;10 (4):800–8. 134. Sohn DW, Chai IH, Lee DJ, et al. Assessment of mitral annulus velocity by Doppler tissue imaging in the evaluation of left ventricular diastolic function. J Am Coll Cardiol. 1997;30(2):474–80. 135. Rodriguez L, Garcia M, Ares M, et al. Assessment of mitral annular dynamics during diastole by Doppler tissue imaging: comparison with mitral Doppler inflow in subjects without heart disease and in patients with left ventricular hypertrophy. Am Heart J. 1996;131(5):982–7. 136. Kolominsky-Rabas PL, Weber M, Gefeller O, et al. Epidemiology of ischemic stroke subtypes according to TOAST criteria: incidence, recurrence, and long-term survival in ischemic stroke subtypes: a population-based study. Stroke. 2001;32(12):2735–40. 137. Eriksson SE, Olsson JE. Survival and recurrent strokes in patients with different subtypes of stroke: a fourteen-year follow-up study. Cerebrovasc Dis. 2001;12(3):171–80. 138. Arboix A, García-Eroles L, Massons J, et al. Predictive clinical factors of in-hospital mortality in 231 consecutive patients with cardioembolic cerebral infarction. Cerebrovasc Dis. 1998;8(1):8–13. 139. European Stroke Organisation (ESO) Executive Committee; ESO Writing Committee. Guidelines for the management of ischaemic stroke and transient ischaemic attack 2008. Cerebrovasc Dis. 2008;25:457–507. 140. Adams HP Jr, del Zoppo G, Alberts MJ, et al. American Heart Association; American Stroke Association Stroke Council; Clinical Cardiology Council; Cardiovascular Radiology and Intervention Council; Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups. Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: the American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists. Stroke. 2007;38(5):1655–711. 141. Dressler FA, Labovitz AJ. Arterial emboli and cardiac masses: Role of transesophageal echocardiography. In: Maurer G, editor. Transesophageal Echocardiography. New York, NY: McGraw-Hill; 1994:111. 142. Rahmatullah AF, Rahko PS, Stein JH. Transesophageal echocardiography for the evaluation and management of patients with cerebral ischemia. Clin Cardiol. 1999;22(6): 391–6.


143. de Bruijn SF, Agema WR, Lammers GJ, et al. Transesophageal echocardiography is superior to transthoracic echocardiography in management of patients of any age with transient ischemic attack or stroke. Stroke. 2006;37(10):2531–4. 144. Strandberg M, Marttila RJ, Helenius H, et al. Transoesophageal echocardiography in selecting patients for anticoagulation after ischaemic stroke or transient ischaemic attack. J Neurol Neurosurg Psychiatr. 2002;73(1):29–33. 145. Harloff A, Handke M, Reinhard M, et al. Therapeutic strategies after examination by transesophageal echocardiography in 503 patients with ischemic stroke. Stroke. 2006;37(3):859–64. 146. Touzé E, Varenne O, Calvet D, et al. Coronary risk stratification in patients with ischemic stroke or transient ischemic stroke attack. Int J Stroke. 2007;2(3):177–83. 147. Hertzer NR, Young JR, Beven EG, et al. Coronary angiography in 506 patients with extracranial cerebrovascular disease. Arch Intern Med. 1985;145(5):849–52. 148. Hoshino A, Nakamura T, Enomoto S, et al. Prevalence of coronary artery disease in Japanese patients with cerebral infarction: impact of metabolic syndrome and intracranial large artery atherosclerosis. Circ J. 2008;72(3):404–8. 149. Adams RJ, Chimowitz MI, Alpert JS, et al. American Heart Association/American Stroke Association. Coronary risk evaluation in patients with transient ischemic attack and ischemic stroke: a scientific statement for healthcare professionals from the Stroke Council and the Council on Clinical Cardiology of the American Heart Association/ American Stroke Association. Stroke. 2003;34(9):2310–22. 150. Dhamoon MS, Sciacca RR, Rundek T, et al. Recurrent stroke and cardiac risks after first ischemic stroke: the Northern Manhattan Study. Neurology. 2006;66(5):641–6. 151. Touzé E, Varenne O, Chatellier G, et al. Risk of myocardial infarction and vascular death after transient ischemic attack and ischemic stroke: a systematic review and metaanalysis. Stroke. 2005;36(12):2748–55. 152. Sorrell VL, Nanda NC. Transesophageal echocardiographic evaluation of coronary arteries for stenosis in the elderly patient. Am J Geriatr Cardiol. 2001;10(1):30–41, 49. 153. Samdarshi TE, Nanda NC, Gatewood RP Jr, et al. Usefulness and limitations of transesophageal echocardiography in the assessment of proximal coronary artery stenosis. J Am Coll Cardiol. 1992;19(3):572–80. 154. Yamagishi M, Miyatake K, Beppu S, et al. Assessment of coronary blood flow by transesophageal two-dimensional pulsed Doppler echocardiography. Am J Cardiol. 1988;62 (9):641–4. 155. Ofili EO, Labovitz AJ, Kern MJ. Coronary flow velocity dynamics in normal and diseased arteries. Am J Cardiol. 1993;71(14):3D–9D. 156. Fusejima K. Noninvasive measurement of coronary artery blood flow using combined two-dimensional and Doppler echocardiography. J Am Coll Cardiol. 1987;10(5):1024–31. 157. Kisanuki A, Murayama T, Matsushita R, et al. Transesophageal Doppler echocardiographic assessment of left coronary blood flow velocity in chronic aortic regurgitation. Am Heart J. 1996;131(1):101–6.

1955

158. Bonninger, M. (a) Blut transfusion bei pernizioser anamie: (b) Zwei Falle von Herz block. (34). 1908:2292. 159. Barasch E, Gottdiener JS, Larsen EK, et al. Clinical significance of calcification of the fibrous skeleton of the heart and aortosclerosis in community dwelling elderly. The Cardiovascular Health Study (CHS). Am Heart J. 2006;151 (1):39–47. 160. Fox E, Harkins D, Taylor H, et al. Epidemiology of mitral annular calcification and its predictive value for coronary events in African Americans: the Jackson Cohort of the Atherosclerotic Risk in Communities Study. Am Heart J. 2004;148(6):979–84. 161. Osterberger LE, Goldstein S, Khaja F, et al. Functional mitral stenosis in patients with massive mitral annular calcification. Circulation. 1981;64(3):472–6. 162. Assudani J, Singh B, Samar A , et al. Live/real time threedimensional transesophageal echocardiographic findings in caseous mitral annular calcification. Echocardiography. 2010;27(9):1147–50. 163. Fox CS, Vasan RS, Parise H, et al. Framingham Heart Study. Mitral annular calcification predicts cardiovascular morbidity and mortality: the Framingham Heart Study. Circulation. 2003;107(11):1492–6. 164. Potpara TS, Vasiljevic ZM, Vujisic-Tesic BD, et al. Mitral annular calcification predicts cardiovascular morbidity and mortality in middle-aged patients with atrial fibrillation: the Belgrade Atrial Fibrillation Study. Chest. 2011; 140(4):902–10. 165. Kaczmarek RG, Silverman BG, Gross TP, et al. The epidemiology of prosthetic heart valves in the United States. Tex Heart Inst J. 1995;22:86–91. 166. Singh P, Inamdar V, Hage FG, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in evaluation of prosthetic valve function. Echocardiography. 2009;26(10):1236–49. 167. Hage FG, Nanda NC; American Society of Echocardiography’s Guidelines and Standards Committee; American College of Cardiology; American Heart Association; European Association of Echocardiography; Japanese Society of Echocardiography; Canadian Society of Echocardiography. Guidelines for the evaluation of prosthetic valves with echocardiography and Doppler ultrasound: value and limitations. Echocardiography. 2010;27(1):91–3. 168. Zoghbi WA, Chambers JB, Dumesnil JG, et al. American Society of Echocardiography’s Guidelines and Standards Committee; Task Force on Prosthetic Valves; American College of Cardiology Cardiovascular Imaging Committee; Cardiac Imaging Committee of the American Heart Association; European Association of Echocardiography; European Society of Cardiology; Japanese Society of Echocardiography; Canadian Society of Echocardiography; American College of Cardiology Foundation; American Heart Association; European Association of Echocardiography; European Society of Cardiology; Japanese Society of Echocardiography; Canadian Society of Echocardiography. Recommendations for evaluation of prosthetic valves with echocardiography

1956


and doppler ultrasound: a report From the American Society of Echocardiography’s Guidelines and Standards Committee and the Task Force on Prosthetic Valves, developed in conjunction with the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography and the Canadian Society of Echocardiography, endorsed by the American College of Cardiology Foundation, American Heart Association, European Association of Echocardiography, a

registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography, and Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2009;22(9):975–1014; quiz 1082. 169. Quere JP, Monin JL, Levy F, et al. Influence of preoperative left ventricular contractile reserve on postoperative ejection fraction in low-gradient aortic stenosis. Circulation. 2006; 113(14):1738–44. 170. Doufekias E, Segal AZ, Kizer JR. Cardiogenic and aortogenic brain embolism. J Am Coll Cardiol. 2008;51(11):1049–59. 171. Nanda NC. Textbook of Color Doppler Echocardiography. Philadelphia, PA: Lea and Febiger, Inc; 1989:178–90.

CHAPTER 80 How to do Echo for the Electrophysiologist Chittur A Sivaram

Snapshot ¾¾ Echocardiography in Supraventricular Tachycardia ¾¾ Left Atrium ¾¾ Atrial Septum ¾¾ Pulmonary Veins

INTRODUCTION The sub-subspecialty of cardiac electrophysiology (EP) has made tremendous strides and remarkable progress in the last three decades. Several major therapeutic advances in EP techniques have resulted in new treatment options, capable of providing favorable clinical outcomes in patients with recurrent arrhythmias. Such innovative therapies in EP include ablation treatment of atrioventricular (AV) nodal reentrant tachycardia, accessory pathways, and atrial fibrillation (AF) as well as device therapy for primary and secondary prevention in ventricular tachyarrhythmias. Echocardiography is frequently performed in rhythm disorders for the initial assessment as well as during follow-up. The appropriate use of transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and intracardiac echocardiography (ICE) is an important responsibility of cardiologists involved in the ordering, performance, and interpretation of echocardiographic modalities.1 The following description will attempt at delineating steps for maximizing the yield of echocardiography in patients with rhythm disorders through a focused approach to echo imaging relevant to the EP diagnosis under consideration. This chapter will be predominantly centered on the use of TTE and TEE.

¾¾ Inferior Vena Cava ¾¾ Echocardiography in Ventricular Tachycardia ¾¾ Echocardiography in Cardiac Implantable Electronic

Devices

Discussion of ICE will not be included in this chapter since ICE is by and large limited to the EP laboratory and performed by the electrophysiologist during EP procedures. The reader is also encouraged to cross-reference to other chapters in the book with overlapping information.

ECHOCARDIOGRAPHY IN SUPRA VENTRICULAR TACHYCARDIA Often the typical patient with supraventricular tachycardia (SVT) has a structurally normal heart and consequently, a completely normal echocardiogram. This is particularly true in AV nodal re-entrant tachycardia (AVNRT). However, several aspects of TTE have special relevance to the preablation assessment in SVT. The preablation TTE should carefully document chamber dimensions including left atrial (LA) size and volume. It will be helpful to the electrophysiologist to have the dimensions of coronary sinus (CS) to facilitate catheters placement in the CS during ablation. Dimension of CS may be obtained from the apical four-chamber view of TTE with posterior angulation of the transducer or with TEE in the lower midesophageal location.

1958


Fig. 80.1: Parasternal long-axis view of transthoracic echocardiogram (TTE) showing dilated coronary sinus (CS) in the left AV groove region (arrow). The descending thoracic aorta is seen outside the pericardial layer while CS is intrapericardial. Dilated CS can be the result of raised right heart pressures or persistent superior vena cava (SVC) drainage into CS.

Fig. 80.2: Apical four-chamber view of transthoracic echocardiogram (TTE) with posterior angulation of transducer demonstrates the dilated coronary sinus (CS).

CS imaging during TEE is done by advancing the TEE probe slightly from the midesophageal four-chamber view. This view will demonstrate the ostium of CS, CS–RA junction as well the terminal part of the CS. A slight further advancement of the TEE probe can often reveal the middle cardiac vein as it drains into the CS. Rarely, ablation of accessory pathways in preexcitation is performed in the middle cardiac vein and assessment of the middle cardiac vein becomes highly relevant to the electrophysiologist. Cannulation of CS is routinely performed in all patients during cardiac ablation. As such, the dimension of CS is an important piece of information to the electrophysiologist. Normal size of the CS is approximately 6 mm. Dilatation of the CS should raise the suspicion of persistent left superior vena cava (PLSVC) drainage to CS. The additional volume of blood drained from the left upper limb through PLSVC causes an increase in CS size. CS is easily imaged by TTE in the parasternal longaxis view as well as the apical four-chamber views with posterior angulation of the probe (Figs 80.1 and 80.2). Differentiation from descending thoracic aorta is aided by the fact the CS is within the pericardium, while descending aorta is extrapericardial. Saline contrast injection from the left arm would confirm the diagnosis further since contrast appears in the CS prior to appearance in the right heart chambers (Fig. 80.3). The approach to EP procedures and device implantation from left subclavian route is significantly influenced by presence of PLSVC.

Two important anatomical landmarks in the CS— the Thebesian valve (located at the junction of CS and right atrium) and the valve of Vieussens (located more proximally within the CS)—are visible during TEE (Fig. 80.4). The valve of Vieussens frequently causes difficulty in catheter advancement within CS,2 and as such might be helpful information in the preablation assessment. Imaging in patients with preexcitation requires additional attention to features of Ebstein’s anomaly due to its association with posteroseptal accessory pathways. Careful demonstration of attachment of the septal leaflet of tricuspid valve relative to anterior mitral leaflet is indicated in all patients with pre-excitation. An apparent apical displacement of tricuspid valve leaflet insertion relative to mitral leaflet insertion in excess of 8 mm/m2 Body surface area (BSA) is consistent with Ebstein’s anomaly (Figs 80.5 and 80.6). The posterior leaflet of the tricuspid valve needs special attention and needs to be carefully looked at to exclude Ebstein’s anomaly; this can be done using TTE in the parasternal right atrium–right ventricle (RA–RV) view with additional posterior angulation of the transducer or using TEE in the transgastric long-axis RA–RV view. A rare morphological association between preexcitation and diverticulae of CS has been described (Fig. 80.7). While cardiac CT and contrast angiography of CS are superior to echocardiography in the detection of CS diverticulae, occasionally TTE or TEE might provide clues toward the diagnosis in the preablation patient with pre-excitation.

Chapter 80: How to do Echo for the Electrophysiologist

1959

Fig. 80.3: Apical four-chamber view of transthoracic echocardiogram (TTE). Saline contrast injection from the left arm shows opacification of coronary sinus (CS) and right heart chambers. The appearance of contrast in CS prior to right heart chambers is diagnostic of persistent left superior vena cava (PLSVC) to CS.

Fig. 80.4: Thebesian valve seen with transesophageal echo cardiogram (TEE) at the junction of coronary sinus (CS) to right atrium.

Fig. 80.5: Parasternal long-axis view transthoracic echocardiogram (TTE), showing dilated right heart chambers in a patient with Ebstein’s anomaly. The anterior right heart was composed of right atrium (RA) with its atrialized portion of right ventricle (RV).

Fig. 80.6: Apical four-chamber view of the same patient as before. Marked apparent apical displacement of the septal and anterior leaflets of tricuspid valve is seen, resulting in a severely dilated right atrium (RA); there is a large atrialized part of the right ventricle (RV).

Scanning Tips

leaflets brought to focus by changing the degree of posterior angulation of transducer. 3. Scan carefully to look for CS diverticulae, a rare morphological association in pre-excitation. 4. In presence of dilated CS, perform left arm saline contrast injection to exclude persistent left SVC drainage to CS.

1. TTE is usually completely normal in SVT. 2. Look for evidence of Ebstein’s anomaly; need to demonstrate septal and posterior leaflet insertion to the annulus; RA–RV view from parasternal window should be used to delineate septal and posterior

1960


Fig. 80.7: Coronary sinus contrast angiography showing pre sence of a diverticulum in pre-excitation (photograph courtesy of Dr Sunny Po, University of Oklahoma).

LEFT ATRIUM In patients with arrhythmias, imaging of the left atrium provides very valuable information to the electrophysiologist, particularly if ablation therapies are being considered. Dilatation of left atrium is frequently seen in patients with atrial arrhythmias such as AF, atrial flutter, and atrial tachycardia. Careful assessment of LA size is critical. Traditionally, the anteroposterior dimension of LA in systole measured using M-mode echocardiography from the parasternal long-axis view of TTE is the standard method for reporting LA size. However, in many patients there is an obvious discordance between LA size measured with M-mode and LA dimension in the superior-inferior axis seen in the apical four-chamber view of TTE. Recent studies have demonstrated a strong correlation of both LA volume and LA volume index with cardiovascular outcomes.3,4 Most of the commercially available echocardiography machines have measurement packages that permit calculation of LA volume using the Simpson’s biplane method during TTE. Care should be taken to obtain stop frame images in systole that clearly demonstrates the LA outlines in the apical four-chamber and two-chamber views, as well as exclusion of LA appendage and pulmonary veins (PVs) from the trace contours. In patients in atrial arrhythmias [AF, A flutter and atrial tachycardias], a significant risk of thromboembolic complications exists. Several findings on TEE correlated to increased thromboembolic events have been described.

Presence of spontaneous echo contrast (SEC; “smoke”) in left atrial appendage (LAA) has been well recognized as a precursor for development of LAA thrombus and embolism.4 SEC can be distinguished from high gain artifact based on the swirling appearance seen only in SEC. LAA thrombus is often present in patients with AF and its confirmation is facilitated by demonstration of the mass abnormality in orthogonal views. Prominent ridges in the LAA (pectinate lines) should not be confused with LAA thrombus. Careful Doppler interrogation of LAA during TEE for assessing emptying velocities is required as part of the assessment of LAA function. A pulsed Doppler sample volume should be placed close to the ostium of LAA. Normal LAA Doppler signal is quadriphasic, with an emptying and filling signal seen in mid-diastolic and late diastole. The mid-diastolic signals frequently have small velocity and might not be easily apparent. Normal LAA emptying velocities are above 0.4 m/s. Reduced emptying velocities are seen in patients with AF, atrial stunning, and in low cardiac output states. An under-recognized application of LAA Doppler is the fact that it serves as a surrogate for atrial contraction and atrial activity, and thus could help in analysis of rhythm. In AF and A Flutter, LAA Doppler signal shows characteristic emptying and filling signals at a rapid rate. The rate and frequency (cycle length) of atrial emptying signal can be measured from the LAA Doppler, thus providing clues to rhythm analysis. The nongeometric shape of LAA poses unique challen ges to the echocardiographer in performing a comprehensive scanning that evaluates the entire LAA for thrombotic masses (Fig. 80.8). To overcome this challenge, at least two orthogonal views of LAA are required to ensure adequate visualization. This can be achieved by sequential dialing up of the scan plane angle or by preset simultaneous orthogonal views offered in some of the newer equipment (Figs 80.9A and B). Diagnostic accuracy of combined two-dimensional (2D TTE) and three-dimensional TTE (3D TTE) when compared with TEE in experienced hands has been excellent. The differentiation of pectinate lines in LAA from thrombus is also aided by 3D TTE (Figs 80.10A to D).5,6 LAA exclusion is recommended in conjunction with mitral valve surgery as well as surgical ablation of AF for maximal protection against thromboembolic risk in both valvular and nonvalvular AF. Exclusion of LAA by clips or suturing offers lesser protection against


1961

Fig. 80.8: Transesophageal echocardiogram (TEE) showing a thrombus (arrow) in the left atrial appendage (LAA) in a patient with atrial fibrillation.

A

B

Figs 80.9A and B: (A) Transesophageal echocardiogram (TEE) showing left atrial appendage (LAA; midesophageal probe position, scan plane angle 54°). Left upper pulmonary vein is seen adjacent to LAA, and it appears that a good demonstration of LAA has been obtained; (B) With additional scan plane angle without any change in probe position, a large additional segment of LAA is now visualized. This underscores the importance of careful scanning of LAA with different scan plane angles to assess the complex shape of LAA.

thromboembolism compared to excision of LAA. Two well-known complications after LAA exclusion are recanalization of LAA and persistence of a LAA remnant. The presence of LAA remnant is accompanied by a greater risk of thromboembolism compared to LAA excision.7 Recanalized LAA often is associated with presence of an emptying and a filling signal seen with color flow Doppler as well as pulsed Doppler (Figs 80.11A and B). Rarely other abnormalities of the LAA might be present, for example, nonobstructive valves, masses such as lipoma.

In patients with AF and A Flutter, worsening of pre-existing SEC might be seen immediately after cardioversion. This is caused by atrial stunning, which results in a reduced atrial transport function even after sinus rhythm has been re-established. Atrial stunning has been known to persist for several weeks postcardioversion.

Scanning Tips 1. Obtain M-mode measurements of LA size. 2. Obtain LA volumes from apical four- and twochamber views.

1962


A

B

C

D

Figs 80.10A to D: (A) Two-dimensional transesophageal echocardiogram. Arrowhead points to an echodense mass within the left atrial appendage (LAA) consistent with a thrombus; (B to D) Three-dimensional transthoracic echocardiogram. Within the LAA there are two echo densities noted. Sequential cropping shows both to be parts of pectinate muscles, which traverse the LAA. The upper echo density (upper arrowhead) is larger because it represents a short-axis cut through two pectinate muscles virtually in contact with each other. This most likely represents the “thrombus” seen on the transesophageal echocardiogram. The second echo density (bottom arrowhead) is smaller because only one pectinate muscle is involved. (LUPV: Left upper pulmonary vein). Source: Reproduced with permission from Karakus G, Kodali V, Inamdar V, Nanda NC, Suwanjutah T, Pothineni KR. Comparative assessment of left atrial appendage by transesophageal and combined two and three-dimensional transthoracic echocardiography. Echocardiography. 2008;25:918–24.

3. Scan LAA in multiple views to demonstrate all areas of the nongeometric LAA. 4. Emptying velocity signal of LAA is a surrogate for atrial activity. 5. Adjust gain appropriately to optimal level for demonstration of SEC.

ATRIAL SEPTUM Abnormalities of atrial septum are occasionally seen in patients undergoing ablation. Preprocedural assessment

of the atrial septum provides important information for procedures requiring trans-septal puncture. The fossa ovalis region is the thinnest part of the atrial septum. The septum secundum is slightly thicker and is seen to the right of the thinner septum primum. Presence of a patent foramen ovale is confirmed by demonstration of a space between the septum primum and secundum along the superior aspect and presence of flow between the two layers of atrial septum using color flow Doppler and saline contrast study.


A

1963

B

Figs 80.11A and B: (A) Transesophageal echocardiogram (TEE) showing a recanalized left atrial appendage (LAA) after surgical exclusion; (B) Peak velocity by continuous wave (CW) Doppler was 3.4 m/s with a peak gradient of 46 mm Hg across the recanalized LAA.

Procedures requiring trans-septal puncture (e.g. PV isolation for AF) often produce a left-to-right shunt at the fossa ovalis region immediately postprocedure. These shunts are invariably small and the defects close spontaneously over time. ICE guidance is used in most ablation laboratories for trans-septal puncture. If the puncture enters the upper part of atrial septum, significant hematoma might result due to entry into the Waterston’s groove (an extracardiac space between the two atria due to in-folding of the atrial walls). A frequent abnormality of the atrial septum in patients undergoing AF ablation is lipomatous atrial septum. Significant thickening of the atrial septum can occur due to deposition of fat and this might be mistaken for an atrial tumor. Typically lipomatous atrial septum spares the fossa ovalis region. Lipomatous atrial septum is more often seen in patients with obesity.

Scanning Tip • Immediately after AF ablation, there is often a left-toright shunt at the site of trans-septal puncture.

PULMONARY VEINS The critical role played by firing from PV in the genesis of AF has now conclusively been recognized. This mechanism is the basis for ablative therapies in AF (PV isolation). Many patients undergoing PV isolation for AF require additional procedures including additional ablation for AF, A Flutter,

and macro-reentrant tachycardia. Thus, the importance of morphological features of PV for the ablation planning has been recognized in such patients undergoing preand postablation assessment. TTE has limited ability to demonstrate PV anatomy. Occasionally, one might be able to see the ostia of right and left upper PV in the apical four-chamber view of TTE. Rarely the left inferior PV might be seen in the parasternal long-axis view. Other imaging techniques are therefore needed for PV imaging. While CT angiography and cardiac MR imaging have been well recognized for their ability in delineating PV anatomy, the role of TEE has been less well recognized. Experience from centers with high volume of TEE have shown that all four PVs can be imaged in an overwhelming number of patients; ostial size, Doppler velocity profile, and other abnormalities can be easily demonstrated.8 A systematic review of published studies shows a diagnostic accuracy rate of TEE for PV abnormalities comparable to CT angiography and cardiac MR imaging.9 PV imaging during TEE is generally performed at the midesophageal level. Left upper PV is adjacent to LAA, while right upper PV is adjacent to SVC. Left lower PV is anatomically close to the descending thoracic aorta. These adjacent anatomical landmarks are helpful in locating PVs. Each PV ostium has an oval shape with a larger and a smaller orthogonal dimension. From the midesophageal probe position during TEE, progressive scan plane angulation combined with counterclockwise torque of the scope will bring up both left upper and lower PVs in a single

1964


Fig. 80.12: Transesophageal echocardiogram (TEE) from midesophageal level, employing 120° scan plane angle as well as torque shows left upper and lower pulmonary veins (PVs).

Fig. 80.13: Transesophageal echocardiogram (TEE) from midesophageal level showing right upper, middle, and lower pulmonary veins (PVs). Right upper PV is adjacent to superior vena cava.

view (Fig. 80.12). Right upper PV can be demonstrated in the caval view by additional dialing of scan plane angle or clockwise torque of the scope. Right lower PV can be imaged by slight additional downward movement of the TEE probe (Fig. 80.13). The ostial dimensions of both lower PVs are smaller compared to upper PVs. The lower PVs are more difficult to image by and large. PV flow should be imaged using pulsed Doppler with the sample volume placed about 1 cm from the ostial site. Occasionally, the localization of PV ostium can be difficult due to a degree of flaring of the PV as they enter LA with the resultant absence of a distinct PV–LA junction. The typical PV flow pattern consists of a systolic forward flow, a diastolic forward flow, and atrial reversal. These patterns are influenced by diastolic dysfunction, LA pressures, and presence of significant mitral regurgitation (MR). It will be essential to have careful assessment of PV velocities preablation for accurate assessment of PV stenosis development. PV stenosis has become a rare complication of ablation therapy for AF since focal ablation within PV is not currently used for AF ablation, but PV isolation by ablation within LA is employed. However, PV stenosis still does occur after AF ablation and it can be readily diagnosed by TEE through assessment of PV dimensions post procedure as well as increased PV velocities (Figs 80.14 and 80.15). Often color flow Doppler shows characteristic focal aliasing within PVs; sampling pulsed Doppler at the point of aliasing reveals increased velocity (usually >1 m/s) and loss of the typical spectral pattern

of low velocity flow signals. Localized stenosis involving only one PV is frequently asymptomatic while stenosis of all four PVs will lead to development of symptomatic pulmonary hypertension.10 The presence of high velocities in PVs immediately after ablative therapies is explained by edema caused by the procedure; this frequently resolves over time. Persistent elevation of PV velocities would be consistent with development of actual scarring and stenosis of PV.

INFERIOR VENA CAVA Postablation complications involving inferior vena cava (IVC) have been described. Routine scanning of IVC is indicated pre- and postablation. IVC can be easily visualized by TTE from the subcostal window. More angulation to bring right-sided structures in view will often demonstrate long segments of the IVC easily. Size and inspiratory collapse of IVC allow prediction of right heart filling pressures. IVC can also be demonstrated using TEE; this requires advancing the TEE probe from the midesophageal four-chamber view to close to the transgastric level. With clockwise torque of the scope, the IVC–RA junction is brought into view. With additional advancement of probe and dialing about 20° to 40° of scan plane angle, both the IVC and hepatic vein are demonstrated. Ablation might be complicated by development of mobile masses in the IVC, close to the IVC–RA junction (Fig. 80.16), very likely representing the development of thrombi from the


A

1965

B

Figs 80.14A and B: (A) Stenosis of the right middle pulmonary vein (PV) after atrial tachycardia ablation. Significant aliasing of color flow is seen at the ostial site of right middle PV; (B) Pulsed Doppler sampling from right middle PV shows marked increase in velocities at the site of aliasing (peak diastolic velocity 1.3 m/s).

A

B

Figs 80.15A and B: (A) Transesophageal echocardiogram (TEE) showing focal aliasing of the left upper pulmonary vein (PV) ostium after atrial fibrillation (AF) ablation; (B) Pulsed Doppler from the left upper PV shows a peak velocity of approximately 1.5 m/s in diastole consistent with PV stenosis.

Fig. 80.16: Transthoracic echocardiogram (TTE) subcostal view showing a floating thrombus in the inferior vena cava (IVC) after an ablative procedure. Patient did not manifest pulmonary embolism.

1966


procedure. Clinically significant pulmonary embolism is infrequent in these patients. No correlation between number of sheaths used and duration of procedure have been demonstrated in patients developing IVC thrombi after ablation.

ECHOCARDIOGRAPHY IN VENTRICULAR TACHYCARDIA Echo imaging with TTE provides highly meaningful information in patients with ventricular tachyarrhythmias. As such, imaging with specific diagnostic possibilities in mind is called for in a patient with ventricular ectopy. Most patients with ventricular arrhythmias have an anatomical substrate (i.e. underlying structural heart disease). Common substrates of ventricular arrhythmias include:11 • Coronary artery disease with scar from prior myoc ardial infarction

• Dilated cardiomyopathy a. Noncompaction • Hypertrophic cardiomyopathy • Infiltrative diseases a. Sarcoid heart disease • Arrhythmogenic RV dysplasia (ARVD) Since ventricular tachycardia (VT) ablations require placement of catheters in left ventricle (LV), the presence of LV apical thrombi should be evaluated. Off-axis scanning of the LV apex and the use of Definity contrast are very helpful techniques for the demonstration of LV apical thrombi. Some EP laboratories are also interested in obtaining information about the degree of aortic arch atherosclerotic burden since ablation of VT requires manipulation of catheters across the arch of aorta. The Table 80.1 lists the common conditions associated with ventricular ectopy and the potential findings that should be carefully looked at during echo imaging.

Table 80.1: Common Conditions Associated with Ventricular Arrhythmias and Associated Echocardiographic Findings

Disease

Characteristic Findings

Coronary artery disease

Increased LV dimensions Reduced fractional shortening Reduced left ventricular ejection fraction (LVEF; Simpson’s biplane) Localized scar (thinning, abnormal wall motion) LV mural thrombi

Dilated cardiomyopathy

Increased LV dimension Reduced fractional shortening Reduced LVEF (Simpson’s biplane) Diffuse hypokinesis LV mural thrombi

Noncompaction12

Increased LV trabeculations Ratio of noncompacted to compacted segments > 2

Hypertrophic cardiomyopathy

Small LV cavity Hyperdynamic LV function Asymmetrical septal hypertrophy Systolic anterior motion of mitral valve Mitral regurgitation Aortic valve midsystolic closure LV outflow gradient (at rest and/or during provocation, e.g. Valsalva maneuver)

Sarcoid heart disease Arrhythmogenic RV dysplasia13

Localized basal septal scars

Contd... Increased right ventricular outflow tract (RVOT) dimensions (≥ 32 mm in the parasternal long-axis view, ≥ 36 mm in the basal short-axis view) Increased echogenicity of moderator band Prominent branching pattern Focal outpouching of RV free wall


1967

Contd... Disease

Characteristic Findings

Sarcoid heart disease

Localized basal septal scars

Arrhythmogenic RV dysplasia

13

Increased right ventricular outflow tract (RVOT) dimensions (≥ 32 mm in the parasternal long-axis view, ≥ 36 mm in the basal short-axis view) Increased echogenicity of moderator band Prominent branching pattern Focal outpouching of RV free wall

The presence of fibromuscular bands in LV has been reported in patients with idiopathic LV ventricular tachycardia (Belhassen VT). Fibromuscular bands in this disease typically run across the LV cavity from the posterolateral free wall to the basal part of the septum.14

ECHOCARDIOGRAPHY IN CARDIAC IMPLANTABLE ELECTRONIC DEVICES Cardiac implantable electronic devices (CIEDs) are indi cated in a broad array of conditions including symptomatic bradycardia (pacing), ventricular arrhy thmias and sudden cardiac arrest (defibrillators for primary and secondary prevention), and severe heart failure [cardiac resynchronization therapy (CRT)]. Echocardiography provides significant information in patients undergoing evaluation for CIEDs as well as when infection and bacteremia complicate CIED therapy. In the preprocedural selection of CIEDs, the task for the echocardiographer is to demonstrate the major features of the underlying structural heart disease and to provide relevant quantitative measurements dictated by the guidelines applicable in CIED therapy. Patients in need of CIED therapy for primary or secondary prevention of VT have underlying structural heart disease (coronary artery disease, hypertrophic cardiomyopathy, or dilated cardiomyopathy) and reduced ejection fraction (EF). Thus, the preprocedural assessment should include careful estimation of EF by Simpson’s method. Selection of patients for CRT is based on symptom level of heart failure and QRS duration. The role of echocardiography in patient selection for CRT is highly controversial and not supported by strong evidence. All patients with CIED infections require echo cardiography to rule out infective endocarditis.15 This is due to the fact that infection in CIED patients may be restricted to the device pocket in which case the duration of antibiotic therapy is shorter. Thus, TEE is required

in patients with CIED and bacteremia prior to device explantation. The presence of “ghosts”—casts comprising inflammatory masses over the leads persisting after lead extraction—has been demonstrated to be associated with worse prognosis in CIED infections.16 Lead extraction is required in CIED infections and one of the complications of this procedure is hemopericardium and cardiac tamponade. In summary, in patients undergoing EP procedures, a unique set of knowledge and skills is required for us to provide the relevant information required by the EP team. Close collaboration between the EP and echocardiography teams along with a process of continuing learning through clinical correlation is required.

REFERENCES 1. Douglas PS, Garcia MJ, Haines DE, et al. ACCF/ASE/ AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011. Appropriate Use Criteria for Echocardiography. J Am Coll Cardiol. 2011;57(9):1126–66. 2. Corcoran SJ, Lawrence C, McGuire MA. The valve of Vieussens: an important cause of difficulty in advancing catheters into the cardiac veins. J Cardiovasc Electrophysiol. 1999;10(6):804–8. 3. Abhayaratna WP, Seward JB, Appleton CP, et al. Left atrial size: physiologic determinants and clinical applications. J Am Coll Cardiol. 2006;47(12):2357–63. 4. Gabriel RS, Klein AL. Managing catheter ablation for atrial fibrillation: the role of echocardiography. Europace. 2008;10 Suppl 3:iii8–13. 5. Karakus G, Kodali V, Inamdar V, et al. Comparative assessment of left atrial appendage by transesophageal and combined two- and three-dimensional transthoracic echocardiography. Echocardiography. 2008;25(8):918–24. 6. Kumar V, Nanda NC. Is it time to move on from twodimensional transesophageal to three-dimensional transthoracic echocardiography for assessment of left atrial appendage? Review of existing literature. Echocardiography. 2012;29(1):112–16.

1968


7. Kanderian AS, Gillinov AM, Pettersson GB, et al. Success of surgical left atrial appendage closure: assessment by transesophageal echocardiography. J Am Coll Cardiol. 2008;52(11):924–9. 8. Stavrakis S, Madden G, Pokharel D, et al. Transesophageal echocardiographic assessment of pulmonary veins and left atrium in patients undergoing atrial fibrillation ablation. Echocardiography. 2011;28(7):775–81. 9. Stavrakis S, Madden GW, Stoner JA, et al. Transesophageal echocardiography for the diagnosis of pulmonary vein stenosis after catheter ablation of atrial fibrillation: a systematic review. Echocardiography. 2010; 27(9):1141–6. 10. Saad EB, Marrouche NF, Saad CP, et al. Pulmonary vein stenosis after catheter ablation of atrial fibrillation: emergence of a new clinical syndrome. Ann Intern Med. 2003;138(8):634–8. 11. Stevenson WG, Soejima K. Catheter ablation for ventricular tachycardia. Circulation. 2007;115(21):2750–60.

12. Stanton C, Bruce C, Connolly H, et al. Isolated left ventricular noncompaction syndrome. Am J Cardiol. 2009; 104(8):1135–8. 13. Marcus FI, McKenna WJ, Sherrill D, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/ dysplasia: proposed modification of the task force criteria. Circulation. 2010;121(13):1533–41. 14. Thakur RK, Klein GJ, Sivaram CA, et al. Anatomic substrate for idiopathic left ventricular tachycardia. Circulation. 1996;93(3):497–501. 15. Sohail MR, Uslan DZ, Khan AH, et al. Management and outcome of permanent pacemaker and implantable cardioverter-defibrillator infections. J Am Coll Cardiol. 2007;49(18):1851–9. 16. Le Dolley Y, Thuny F, Mancini J, et al. Diagnosis of cardiac device-related infective endocarditis after device removal. JACC Cardiovasc Imaging. 2010;3(7):673–81.

CHAPTER 81 Echocardiography in Life-Threatening Conditions Rachel Harris, Elizabeth Ofili

Snapshot  Chest Trauma  Blunt Chest Trauma  PenetraƟng Chest Trauma  Acute Mitral RegurgitaƟon  Acute Severe AorƟc RegurgitaƟon  AorƟc DissecƟon

INTRODUCTION The uses of two-dimensional transthoracic and transesophageal echocardiography have proven vital in risk stratification of patients who present with life-threatening conditions.1 In evaluating patients with hemodynamic instability, new or worsening heart murmur, or a recent history of blunt or penetrating trauma, echocardiography has become the mainstay in identifying those with critical injuries in need of surgical or immediate invasive intervention. Transthoracic echocardiography is both sensitive and specific for identification of pericardial effusion, pericardial injury, and peritoneal fluid in the setting of anterior chest trauma.2 The advantages of transthoracic echo are its bedside availability, noninvasive characteristics, and ability to provide rapid information regarding cardiac structure and function. Transesophageal echo has greater sensitivity and specificity in evaluating valvular and aortic pathology, prosthetic valves, interatrial shunts, and cardiac sources of emboli but is more invasive (Table 81.1).3

 Debakey ClassificaƟon  The Stanford ClassificaƟon  Pulmonary Thromboembolic Disease  Air Embolism  Hypovolemia  Large Intracardiac Thrombus

CHEST TRAUMA In 2010, among US persons aged 1–44, unintentional injury was the number one cause of death.5 Cardiac injuries are among the most lethal of thoracic trauma patients, especially in penetrating injuries.6,7 In this same age group, the majority of nonfatal hospital injury visits were secondary to blunt force trauma.8 Although the majority of these patients die in the field from their injuries, among the survivors who present to the emergency department, meticulous detail and a high index of suspicion must be held for the hemodynamically stable patient who may rapidly deteriorate post presentation.

BLUNT CHEST TRAUMA This type of injury is more commonly the direct result of assault, motor vehicle collisions, falls, or fallen objects more commonly. There are numerous injuries that should be suspected depending on the mode of injury. In the case of blunt objects whose force may decrease the chest wall’s

1970


Table 81.1: Perioperative Indications for use of Transesophageal Echocardiogram in Trauma Patients

Category 1

Acute hemodynamic instability in which ventricular function and its determinants are uncertain and have not responded to treatment Unstable patient with unexplained hemodynamic disturbances, suspected valvular pathology, or thromboembolism Immediate evaluation of patient with suspected thoracic aortic pathology: aneurysm, dissection, or disruption Pericardial window procedures

Category 2

At risk for myocardial ischemia or infarction or hemodynamic disturbances Detection of air embolism or foreign body Suspected cardiac trauma Evaluation of pericardial effusion

Category 3

Evaluation of thoracic trauma in patient with low-suspicion of injury Intraoperative assessment of repair of thoracic aortic injury

Category 1: Supported by the strongest evidence or expert opinion Category 2: Supported by weaker evidence and expert consensus Category 3: Little current scientific or expert support Source: Adapted from the 1999 ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography examination: recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography.3,4

anteroposterior diameter, puncture injuries from ribs may result. Moreover, right atrial and ventricular free wall rupture, massive hemothorax, and cardiac tamponade have also been documented.9

Cardiac Tamponade Echocardiography results in the diagnosis of cardiac tamponade as well as assists in rapid management and treatment, that is, echocardiographically guided pericardiocentesis with catheter drainage.10 Patients presenting with hemodynamic instability post penetrating or blunt force chest trauma should be emergently evaluated for cardiac involvement, namely, myocardial contusion or pericardial effusion.11,12 The clinical presentation of diaphoresis, dyspnea, muffled heart sounds, and hypotension should warrant further evaluation for pericardial effusion.11,13,14 Careful evaluation using parasternal long- and short-axis, apical four-chamber, and subcostal windows should be undertaken as well as the use of M-mode.15 Evaluation of diastolic right ventricular collapse can be demonstrated as well as right atrial collapse/inversion. Diastolic right ventricular collapse is more specific but less sensitive than right atrial diastolic collapse. While most cases of cardiac tamponade are immediate, there are rare reported cases of delayed tamponade up to 70 days post injury (Figs 81.1 to 81.4).16

Fig. 81.1: Parasternal long-axis with large circumferential pericardial effusion (PE). (AO: Aorta; DA: Descending aorta; IVS: Interventricular septum; LA: Left atrium; PW: Posterior wall) (Movie clip 81.1).

With Doppler, there may be evidence of exaggerated respiratory variation in inflow velocity. The transtricuspid and transmitral inflow velocities should not vary by more than 25% or 15%, respectively (Fig. 81.5).10 When evaluating the pulmonary and aortic inflow velocities, these should not vary by >10%.10 There may also be evidence of phasic variation in the right and left ventricular outflow tract (LVOT) and exaggerated

Chapter 81: Echocardiography in Life-Threatening Conditions

1971

Fig. 81.2: Subcostal view of anterior pericardial fluid. Arrowhead points to diastolic right ventricular collapse. (L: Liver; LV: Left ventricle; PE: Pericardial effusion) (Movie clip 81.2).

Fig. 81.3: Parasternal short-axis of right ventricular (RV) diastolic collapse (arrowhead) and pericardial effusion (PE). (LV: Left ventricle) (Movie clip 81.3).

Fig. 81.4: M-mode demonstrating right ventricular wall (RVW) diastolic collapse (arrow). (CW: Chest wall).

Fig. 81.5: Tricuspid valve (TV) respiratory flow variation. (LV: Left ventricle; RV: Right ventricle).

respiratory variation in inferior vena cava (IVC) flow.17 The operator will also likely see a plethoric (distended) IVC (in the absence of hypovolemia).

biochemical cardiac markers.18 Cardiac contusion can occur as a direct result of pressure on the myocardium caused by deceleration forces that affect the chest wall or indirectly secondary to shear stresses and increased intrathoracic pressures.19–21 Noninvasive attempts to characterize cardiac contusion have aimed at evaluating the combination of ECG, cardiac enzymes, use of telemetry, and echocardiogram (notably transthoracic echo). ECG changes may be associated with ST depression, but

Cardiac Contusion The definition of cardiac contusion is a histological diagnosis. However, the clinical diagnosis relies on the sum of echo findings, electrocardiogram (ECG), and

1972


these findings are not specific for myocardial ischemia. However, should a patient have ECG changes, they should be monitored at least 24 hours for arrhythmias.20,21 Both CPK Mb and troponin levels have been evaluated in terms of their sensitivity and specificity, and troponin is more specific. Post trauma, the CPK Mb has been shown to be elevated in noncardiac injuries.20,21 Using bedside transthoracic echocardiogram (TTE), the operator can examine for possible focal wall motion abnormalities, valvular involvement, focal wall rupture, pericardial effusion, or great vessel injury (Figs 81.6A and B).

PENETRATING CHEST TRAUMA Penetrating chest injury may be caused by a knife, gun, rifle, or any sharp or impaling object through the skin. The path of entry to exit should be closely examined with consideration of possible cardiac structures and/or vessels involved. Wounds to the inferolateral left parasternal regions call for close evaluation of the LV, whereas lower right and left parasternal wounds call for right ventricular evaluation.22 Involvement of the interventricular septum is also common as well as free wall rupture.47 Doppler evaluation of suspected areas of involvement should also be performed.23 If intracardiac missiles are visualized, they may distally embolize and their location should be reported.24 In the setting of chest wall emphysema or hemothorax, the sensitivity of transthoracic echo is decreased and transesophageal echocardiogram (TEE) should be considered if the patient remains clinically stable and passage of the TEE probe can be safely conducted (Figs 81.7A to D).

A

ACUTE MITRAL REGURGITATION Postpenetrating or blunt injury, myocardial infarction or endocarditis, acute mitral regurgitation (MR) from possible valve, chord or papillary muscle involvement must be considered. Careful evaluation of the plane of the penetrating injury should be performed. Standard parasternal long-axis, parasternal short-axis, apical fourand two-chamber as well as subcostal images should be obtained during transthoracic echo. For transesophageal echocardiography, transgastric short- and long-axis and midesophageal four- and two-chamber, and long-axis views are optimal. M-mode assessment can assist in further evaluation of the possible mechanism of the regurgitation as well as give useful information regarding volume status (i.e. M-mode evidence of B-bump on the AC shoulder in increased LV end-diastolic pressure states). If possible, a determination of the mechanism (i.e. perforation of valve leaflet, pap muscle dysfunction vs. rupture, chordal involvement), severity and repairability of the MR should be performed. This may involve transesophageal echo evaluation if the patient remains hemodynamically stable (Figs 81.8 to 81.10 and Table 81.2).

ACUTE SEVERE AORTIC REGURGITATION Acute aortic regurgitation can occur commonly with trauma, aortic dissection, and infective endocarditis. Close attention must be paid to several clinical factors in considering a patient with acute aortic regurgitation. The

B

Figs 81.6A and B: Parasternal short-axis view (apical level) in end diastole (A) and end-systole (B). Note the focal inferior wall akinesis (arrows) and small pericardial effusion (PE) in a patient post trauma. (LV: Left ventricle) (Movie clip 81.6A and B).


1973

Table 81.2: Classification of Severe Mitral Regurgitation

Color Doppler jet area

Vena contracta width > 0.7 cm with large central mitral regurgitation (MR) jet [area > 40% of left atrium (LA) area] or with a wall-impinging jet of any size, swirling in LA

Doppler vena contracta width (cm)

≥ 0.70

Regurgitant volume (mL/beat)

≥ 60

Regurgitant fraction (%)

≥ 50

Regurgitant orifice area (cm2)

≥ 0.40

Source: Adapted from Bonow RO, Carabello BA, Chatterjee K, et al. ACC/AHA 2006 Practice Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary. J Am Coll Cardiol. 2006;48(3):598–675.25

A

B

C

D

Figs 81.7A to D: Short-axis at the level of the mitral valve showing a small ventricular septal defect (VSD) without (A) and with (B) color (arrow). Three months later, the VSD was noted to be significantly larger, measuring 1.5 cm in diameter shown without (C) and with (D) color (arrows). (LV: Left ventricle; RV: Right ventricle). Courtesy of Dr Robert Chisholm, St Michael’s Hospital, Toronto, ON, with permission.47

1974


Fig. 81.8: Color Doppler evidence of severe mitral regurgitation (MR). (LA: Left atrium; LV: Left ventricle; PA: Pulmonary artery) (Movie clip 81.8).

Fig. 81.9: Prolapse of P3 scallop (arrow in Movie clip 81.9A). (LA: Left atrium; LV: Left ventricle; MR: Mitral regurgitation) (Movie clips 81.9A and 81.9B).

M-mode is also useful in assessing for premature closure of the mitral valve (prior to QRS onset) and diastolic fluttering of the anterior mitral valve leaflet (specific but not sensitive).25 Doppler may also reveal evidence of diastolic MR (Figs 81.11 to 81.14 and Table 81.3).

AORTIC DISSECTION TTE and TEE are both are indicated (Class I) in diagnostic imaging of suspected aortic dissection.26 The type and extent of the dissection should be determined.

DEBAKEY CLASSIFICATION Fig. 81.10: Doppler evidence of severe mitral regurgitation (arrow; Vmax, 4.67 m/s). (LA: Left atrium; LV: Left ventricle).

pulse pressure in acute regurgitation may be normal to only mildly increased, given rapid equalization of pressures versus in a chronic, compensated state [LV dilatation, eccentric left ventricular hypertrophy (LVH), and a large stroke volume] the pulse pressure can be very wide. The LV and left atrial dimensions should be assessed with normal values indicating an acute decompensation. The standard transthoracic views to assess regurgitation severity are the apical three- and five-chamber, suprasternal notch, and right parasternal windows. For assessment of the LVOT diameter, the parasternal long-axis view is optimal.

Type I: Originates in ascending aorta, propagates at least to the aortic arch, and often beyond it distally. Type II: Originates in and is confined to the ascending aorta. Type III: Originates in descending aorta, rarely extends proximally but will extend distally.

THE STANFORD CLASSIFICATION Type A: All dissections involving the ascending aorta, regardless of the site of origin (DeBakey types I and II). Type B: All dissection not involving the ascending aorta (DeBakey type III; Table 81.4). The diagnosis of aortic dissection is visualization of two wall lumina separated by an intimal flap


1975

Table 81.3: Classification of Severe Aortic Regurgitation

Color Doppler jet width

Central jet, width > 65% left ventricular outflow tract (LVOT)

Doppler vena contracta width (cm) Regurgitant volume (mL/beat) Regurgitant fraction (%)

> 0.60 ≥ 60 ≥ 50

Regurgitant orifice area (cm2)

≥ 0.30

Pressure Half-time (ms)

< 200

Color M-mode propagation velocity (cm/sec)

≥ 80

Source: Adapted from Bonow RO, Carabello BA, Chatterjee K, et al. ACC/AHA 2006 Practice Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary. J Am Coll Cardiol. 2006;48(3):598–675.25

Fig. 81.11: Aortic valve rupture. Long-axis view reveals flail right coronary cusp (arrow) resulting in severe acute aortic regurgitation. (AO: Aorta; LA: Left atrium; LV: Left ventricle) (Movie clip 81.11).

Fig. 81.12: Color Doppler examination showing severe aortic regurgitation (AR). (AO: Aorta; LA: Left atrium; RV: Right ventricle) (Movie clip 81.12).

Fig. 81.13: M-mode of mitral valve (MV) revealing early diastolic closure (arrow) due to severe aortic regurgitation. (AO: Aorta; LA: Left atrium; LV: Left ventricle).

Fig. 81.14: Color Doppler superimposed on M-mode tracing. Evidence of pan-diastolic regurgitation (arrow). (LVO: Left ventricle outflow).

1976


Table 81.4: Standard Two-Dimensional Transthoracic Views in Evaluating Aortic Dissection27–29

Left Parasternal

Ascending aorta

Apical

Ascending aorta

Subcostal

Ascending aorta

Right parasternal

Ascending aorta

Suprasternal Notch

Aortic arch

Paraspinal

Descending aorta

causes difficulty in visualizing small dissection areas in the distal ascending aorta and anterior aortic arch that may be encountered if not using a multiplane transesophageal probe.31,32

PULMONARY THROMBOEMBOLIC DISEASE

(Figs 81.15A and B).30 Evidence of tears may lead to propagation of the dissection either proximally or distally. Characteristics of the true lumen are systolic expansion and diastolic collapse, the absence or low intensity of spontaneous echocardiographic contrast, systolic jets directed away from the lumen, and systolic forward flow. Characteristics of the false lumen are diastolic diameter increase, spontaneous echocardiographic contrast, and reversed, delayed, or absent flow and thrombus formation.27,29,30 Flow signals within the false lumen represent signs of communication (Figs 81.16 and 81.17). There are a few special considerations when performing transesophageal imaging. The number of tears should be documented as well as the location of each (distance from teeth to tip of probe).26 Moreover, there is a “blind” zone caused by overlap of the trachea and the left main stem bronchus between the esophagus and the aorta, which

Right ventricular dysfunction and dilatation may be evident in massive or submassive pulmonary thrombo-embolic (PTE) disease. Not all patients presenting with PTE need urgent echocardiographic evaluation but it may be useful in determining prognosis as well as the need for thrombolysis (Fig. 81.18). Mortality rates for acute PTE can exceed 15% in the first 3 months post diagnosis.33–35 A common specific finding on echo is evidence of pressure overload, (Figs 81.19A to D) described by Nazeyrollas et al. as right ventricle/left ventricle End-diastolic dimension (RV/LVEDD) > 0.5 (parasternal M-mode echo) and tricuspid insufficiency (TI) with a jet velocity > 2.5 m/s.36 Furthermore, a RV/LVEDD ratio of 0.9 or greater (left parasternal long-axis or subcostal view) is an independent predictor of hospital mortality.37 The findings of akinesia of the mid right ventricular free wall but normal motion of the apex are referred to as the McConnell’s Sign.38 This phenomenon has a reported 77% sensitivity and a 94% specificity for the diagnosis of acute pulmonary thromboembolism in the setting of right ventricular dysfunction.36,38

A

B

Two-dimensional echo Doppler and M-mode standard views reveal key portions of the aorta

Figs 81.15A and B: Descending aortic dissection with intimal flap (arrows). (FL: False lumen; TL: True lumen). Courtesy of Dr Anekwe Onwuanyi, Morehouse School of Medicine, Atlanta, GA (Movie clip 81.15).


Fig. 81.16: Color Doppler with evidence of flow signals in the false lumen (FL) consistent with communication. (TL: True lumen) (Movie clip 81.16).

Fig. 81.18: Echogenic structure (arrowhead) in right atrium (RA) consistent with thrombus in transit in a patient subsequently diagnosed with acute pulmonary thromboembolism. (LA: Left atrium; LV: Left ventricle; MV: Mitral valve; RV: Right ventricle) (Movie clip 81.18).

AIR EMBOLISM Air embolism can result post multiple injuries including blunt and penetrating chest trauma (Fig. 81.20). It may result in air in the coronary arteries and Doppler findings on echo consistent with air in cardiac chambers or major arteries.39 When a patent foramen ovale is present, a very small amount of air can result in paradoxical emboli. Patients may present with hemodynamic instability, respiratory distress, or postcardiac arrest. Physical exam findings may be the appearance of cutaneous petechiae.

1977

Fig. 81.17: Spontaneous contrast in false lumen (FL). (TL: True lumen) (Movie clip 81.17).

A

B

C

D

Figs 81.19A to D: (A) Patient who presented with submassive acute pulmonary thromboembolism and right heart strain. Interatrial septum bows into the left atrium (LA) consistent with elevated right atrial (RA) pressures. (B) “D” sign (arrow) revealing right ventricular (RV) pressure overload and pulmonary hypertension. (C) Tricuspid regurgitant (TR) velocity > 4 m/s; (D) Dilated inferior vena cava (IVC) with no inspiratory collapse. (LV: Left ventricle) (Movie clip 81.19B).

Prompt identification is needed to assist in definitive treatment.

HYPOVOLEMIA Consideration of hypovolemia should be part of the differential in patients with hypotension. The size of the left and right ventricles are not reliable indicators of hypo-volemia;

1978


Fig. 81.20: Air (small echogenic shructures) noted in left atrium (LA) and left atrial appendage (LAA; Arrows) (Movie clip 81.20).

A

B

Figs 81.21A and B: Normal sized left ventricle (LV) with hyperdynamic state in hypotensive patient. End diastole (A) and end systole (B). (Movie clip 81.21).

however, in severe hypovolemia, the left and right ventricles are small and hyperkinetic, with evidence of systolic collapse of the LV (Figs 81.21 and 81.22).40–42 A small IVC (< 1.2 cm) has a 100% specificity (low sensitivity) for a RA pressure of <10 mm Hg.43

LARGE INTRACARDIAC THROMBUS Thrombus is defined as a discrete echodense mass with defined margins that are distinct from the endocardium and seen throughout systole and diastole. They can occur in the setting of low flow or stasis. Cardiac thrombi may predispose the patient to significant morbidity and mortality. They may be formed de novo or identified as right heart embolism while in transit. There are several causes including atrial fibrillation, atrial flutter, atrial appendage, LV aneurysm formation,

Fig. 81.22: Transesophageal echocardiogram (TEE). Parasternal long-axis view reveals small left ventricular (LV) diastolic dimensions indicating severe hypovolemia. (AO: Aorta; LA: Left atrium; RV: Right ventricle) (Movie clip 81.22).


A

1979

B

Figs 81.23A and B: Apical views. Left ventricular (LV) apical mobile thrombus (arrow) in newly diagnosed congestive heart failure (CHF) in a patient who suffered a stroke 2 weeks later on anticoagulation therapy. (MV: Mitral valve; RV: Right ventricle) (Movie clips 81.23A and B)

make a formal diagnosis. Transesophageal images are not superior over transthoracic images for identification of LV thrombi as the apex is usually foreshortened but is 100% sensitive and 99% specific in identifying left atrial and left atrial appendage thrombus (Fig. 81.24).44 The appearance of thrombi can vary from a heterogeneous, echolucent, protruding masses (in newly formed thrombus) to a homogenous, smooth mass in chronic states.46

SUMMARY In life-threatening conditions, both two-dimensional TTE and TEE are essential in rapid risk stratification, via evaluation of cardiac structures and function, as well as Fig. 81.24: Left atrial thrombus (LA: arrow) extending into left atrial remain a current noninvasive and more cost-effective appendage (not shown) in a patient with severe mitral stenosis. mainstay in diagnosis and treatment strategies. (AV: Aortic valve) (Movie clip 81.24).

REFERENCES valvular disease, intracardiac devices, postmyocardial infarction, deep venous thrombosis, and malignancy more commonly. Transthoracic echo has a sensitivity of 90–95% and a specificity of 85–90% for detection of LV thrombi where the presence of thrombus was confirmed at surgery or autopsy (Figs 81.23A and B).43,44 LV mural thrombi are more difficult to diagnose when contrast agents are not used.45 Optimal views for imaging LV thrombi are apical images that position the ventricular apex in the near field. The mass should be visualized in at least two views to

1. Reid CL, Kawanishi DT, Rahimtoola SH, et al. Chest trauma: evaluation by two-dimensional echocardiography. Am Heart J. 1987;113(4):971–6. 2. Tayal VS, Beatty MA, Marx JA, et al. FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma. J Ultrasound Med. 2004;23(4):467–72. 3. Marciniak D, Smith CE. Pros and cons of transesophageal echocardiography in trauma care. Internet J Anesth. 2010;23(2). DOI: 10.5580/81. 4. Shanewise JS, Cheung AT, Aronson S, et al. ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography

1980

5.

6.

7.

8.

9.

10.

11.

12.

13.

14. 15.

16.

17.

18.

19.

20. 21.


examination: recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography. Anesth Analg. 1999; 89(4):870–84. National Vital Statistics System, National Center for Health Statistics, CDC; [online] CDC Website; Available from http://web.appa.cdc.gov [Accessed January 2013]. Körner M, Krötz MM, Degenhart C, et al. Current Role of Emergency US in Patients with Major Trauma. Radiographics. 2008;28(1):225–42. Adams A, Fotiadis N, Chin JY, et al. A pictorial review of traumatic pericardial injuries. Insights Imaging. 2012; 3(4):307–11. The National Electronic Injury Surveillance System. NEISS All Injury Program operated by the Consumer Product Safety Commission (CPSC), CDC; [online] CDC Website; Available from http://www.cdc.gov/ncipc/wisqars/nonfatal/datasources.htm [Accessed January 2013]. Griffith GL, Zeok JV, Mattingly WT Jr, et al. Right atrial rupture due to blunt chest trauma. South Med J. 1984;77(6):715–16. Tsang TS, Oh JK, Seward JB, et al. Diagnostic value of echocardiography in cardiac tamponade. Herz. 2000; 25(8):734–40. Thakur RK, Aufderheide TP, Boughner DR. Emergency echocardiographic evaluation of penetrating chest trauma. Can J Cardiol. 1994;10(3):374–6. Jimenez E, Martin M, Krukenkamp I, et al. Subxiphoid pericardiotomy versus echocardiography: a prospective evaluation of the diagnosis of occult penetrating cardiac injury. Surgery. 1990;108(4):676–9; discussion 679. Porter JM, Page R, Wood AE, et al. Ventricular perforation associated with central venous introducer-dilator systems. Can J Anaesth. 1997;44(3):317–20. Rogers FB, Leavitt BJ. Upper torso cyanosis: a marker for blunt cardiac rupture. Am J Emerg Med. 1997;15(3):275–6. Martin M, et al. 2-D echocardiography: emergent use in the evaluation of penetrating precordial trauma. J Trauma. 1991;31(7):902–5. Rendón F, Gómez Danés LH, Castro M. Delayed cardiac tamponade after penetrating thoracic trauma. Asian Cardiovasc Thorac Ann. 2004;12(2):139–42. Feigenbaum H, Amstrong WF, et al. Feigenbaum’s Echocardiography. 6th ed. Lippincott Williams & Wilkins; 2005: 256. Sybrandy KC, Cramer MJ, Burgersdijk C. Diagnosing cardiac contusion: old wisdom and new insights. Heart. 2003;89(5):485–9. Wisner DH, Reed WH, Riddick RS. Suspected myocardial contusion. Triage and indications for monitoring. Ann Surg. 1990;212(1):82–6. Tenzer ML. The spectrum of myocardial contusion: a review. J Trauma. 1985;25(7):620–7. Kaye P, O’Sullivan I. Myocardial contusion: emergency investigation and diagnosis. Emerg Med J. 2002;19:8–10.

22. Wilson RF, Bassett JS. Penetrating wounds of the pericardium or its contents. JAMA. 1966;195(7):513–18. 23. Moore EE. Traumatic ventricular septal defect. Surgery. 2007;142(5):776–7. 24. Nguyen R, Ouedraogo A, Deneuville M. Gunshot wounds to the chest with arterial bullet embolization. Ann Vasc Surg. 2006;20(6):780–3. 25. Bonow RO, Carabello BA, Chatterjee K, et al. ACC/AHA 2006 Practice Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary. J Am Coll Cardiol. 2006;48(3):598–675. 26. Clouse WD, Hallett JW Jr, Schaff HV, et al. Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture. Mayo Clin Proc. 2004;79(2):176–80. 27. Mintz GS, Kotler MN, Segal BL, et al. Two dimensional echocardiographic recognition of the descending thoracic aorta. Am J Cardiol. 1979;44(2):232–8. 28. Khandheria BK, Tajik AJ, Taylor CL, et al. Aortic dissection: review of value and limitations of two-dimensional echocardiography in a six-year experience. J Am Soc Echocardiogr. 1989;2(1):17–24. 29. Erbel R, Alfanso F, Boileau C, et al. Diagnosis and management of aortic dissection. Recommendations of the Task Force on Aortic Dissection, European Society of Cardiology. Eur. Heart J. 2001;22:1642–81. 30. Erbel R, Oelert H, Meyer J, et al. Influence of medical and surgical therapy on aortic dissection evaluated by transesophageal echocardiography. Circulation. 1993; 87:1604–15. 31. Erbel R, Engberding R, Daniel W, et al. Echocardiography in diagnosis of aortic dissection. Lancet. 1989;1(8636): 457–61. 32. Kanojia A, Kasliwal RR. Recent advances in echocardiography of aortic disorders. Asian Cardiovasc Thorac Ann. 1998;6:153–7. 33. Lankeit M, Jiménez D, Kostrubiec M, et al. Predictive value of the high-sensitivity troponin T assay and the simplified Pulmonary Embolism Severity Index in hemodynamically stable patients with acute pulmonary embolism: a prospective validation study. Circulation. 2011;124(24):2716–24. 34. Torbicki A. Echocardiographic diagnosis of pulmonary embolism: a rise and fall of McConnell sign? Eur J Echocardiogr. 2005;6(1):2–3. 35. Goldhaber SZ, Visani L, De Rosa M. Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER). Lancet. 1999;353(9162):1386–9. 36. Nazeyrollas P, Metz D, Jolly D, et al. Use of transthoracic Doppler echocardiography combined with clinical and electrocardiographic data to predict acute pulmonary embolism. Eur Heart J. 1996;17(5):779–86. 37. Frémont B, Pacouret G, Jacobi D, et al. Prognostic value of echocardiographic right/left ventricular end-diastolic diameter ratio in patients with acute pulmonary embolism:


38.

39.

40.

41.

42.

43.

results from a monocenter registry of 1,416 patients. Chest. 2008;133(2):358–62. McConnell MV, Solomon SD, Rayan ME, et al. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism. Am J Cardiol. 1996;78(4): 469–73. Yee ES, Verrier ED, Thomas AN. Management of air embolism in blunt and penetrating thoracic trauma. J Thorac Cardiovasc Surg. 1983;85(5):661–8. Charron C, Caille V, Jardin F, et al. Echocardiographic measurement of fluid responsiveness. Curr Opin Crit Care. 2006;12(3):249–54. Feissel M, Michard F, Faller JP, et al. The respiratory variation in inferior vena cava diameter as a guide to fluid therapy. Intensive Care Med. 2004;30(9):1834–7. Barbier C, Loubières Y, Schmit C, et al. Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients. Intensive Care Med. 2004;30(9):1740–6. Jue J, Chung W, Schiller NB. Does inferior vena cava size predict right atrial pressures in patients receiving

44.

45.

46.

47.

1981

mechanical ventilation? J Am Soc Echocardiogr. 1992; 5(6):613–19. Weinsaft JW, Kim RJ, Ross M, et al. Contrast-enhanced anatomic imaging as compared to contrast-enhanced tissue characterization for detection of left ventricular thrombus. JACC Cardiovasc Imaging. 2009;2:969–79. Weinsaft JW, Kim HW, Crowley AL, et al. LV Thrombus Detection by Routine Echocardiography. Insights Into Performance Characteristics Using Delayed Enhancement CMR. JACC: Cardiovascular Imaging. July 2011;4(7): 702–12. Pepi M, Evangelista A, Nihoyannopoulos P, et al.; European Association of Echocardiography. Recommendations for echocardiography use in the diagnosis and management of cardiac sources of embolism: European Association of Echocardiography (EAE) (a registered branch of the ESC). Eur J Echocardiogr. 2010;11(6):461–76. Dehghani P, Ibrahim R, Collins N, et al. Post-traumatic ventricular septal defects–review of the literature and a novel technique for percutaneous closure. J Invasive Cardiol. 2009;21(9):483–7.

CHAPTER 82 Lung Ultrasound in Cardiology Luna Gargani, Eugenio Picano

Snapshot ¾¾ Physical and Physiological Basis of Lung Ultrasound ¾¾ Methodology ¾¾ Pulmonary Interstitial Edema ¾¾ Pleural Effusion ¾¾ Pulmonary Embolism

INTRODUCTION Assessment of the lung has always been considered off-limits for ultrasound, since it is standard textbook knowledge that “because ultrasound energy is rapidly dissipated by air, ultrasound imaging is not useful for the evaluation of the pulmonary parenchyma.”1 However, in recent years, lung ultrasound scan (LUS) has proved to be a useful tool for evaluating many different acute and chronic heart and lung disease conditions.2 It is especially valuable because it is a very easy application of echography, far less technically demanding than echocardiography,3 rapid to perform and interpret, portable, repeatable, non-ionizing, and independent of the cardiac acoustic window. Thus, it is suitable for a quick but meaningful evaluation for both in-patients and out-patients.

PHYSICAL AND PHYSIOLOGICAL BASIS OF LUNG ULTRASOUND All diagnostic ultrasound methods are based on the principle that ultrasound is reflected by an interface between media with different acoustic impedance. In normal conditions, with aerated lungs, the ultrasound beam finds the lung air and no image can be depicted because the ultrasound beam is rapidly dissipated by the air.4 The only detectable structure is the pleura, visualized

¾¾ Acute Respiratory Distress Syndrome ¾¾ Pneumothorax ¾¾ Cardiopulmonary Ultrasound: An Integrated Approach ¾¾ Limitations

as a hyperechoic horizontal line, moving synchronously with respiration (Fig. 82.1, Movie clip 82.1). This dynamic horizontal movement synchronized with respiration is called lung sliding. In an aerated lung, several hyperechoic horizontal lines, arising at regular intervals from the pleural line, can be seen—these are called A-lines and are not pathological. When the air content decreases, the acoustic mismatch needed to reflect the ultrasound beam is created, and some images appear. In the presence of extravascular lung water (EVLW), the ultrasound beam finds subpleural interlobular septa thickened by edema. The reflection of the beam creates some comet-tail reverberation artifacts, called B-lines or ultrasound lung comets (Fig. 82.2; Movie clip 82.2). B-lines are defined as discrete laser-like vertical hyperechoic reverberation artifacts that arise from the pleural line, extend to the bottom of the screen without fading, and move synchronously with lung sliding.5 The physical basis of the cardiogenic watery B-lines also explains the source of pneumogenic fibrotic B-lines, which are found in the presence of interstitial pulmonary fibrosis.6 The physical scatterer is represented by waterthickened interlobular septa with cardiogenic B-lines, and by connective tissue-thickened interlobular septa with pneumogenic B-lines. The two types of B-lines can pose a challenge to differential diagnosis, although several clues may help distinguish the two entities. Cardiogenic

Chapter 82: Lung Ultrasound in Cardiology

Fig. 82.1: Sonographic appearance of a normal lung.

1983

Fig. 82.2: Sonographic appearance of multiple B-lines (indicated by the white arrows).

extravascular lung water very early in the course of lung injury in pigs, even at a stage when no changes in hemoga sanalytic parameters can be observed.9

METHODOLOGY

Fig. 82.3: Sonographic appearance of a consolidated lung. The echotexture becomes similar to that of the liver.

B-lines are always bilateral and are generally more diffuse in the right lung than the left lung, with a “hot zone” of higher density along the axillary lines (in lying patients, as decubitant regions).7 Moreover, cardiogenic B-lines can be dissolved in a few hours by an acute diuretic load.8 For a further reduction in the air content, when the lung is consolidated, it is possible to visualize the pulmonary parenchyma as a solid parenchyma, just like the liver or the spleen (Fig. 82.3). B-lines are a very early event in the cascade, leading to pulmonary edema, as has been shown in an experimental model of oleic acid-induced lung injury, which mimics human acute respiratory distress syndrome (ARDS). B-lines unmasked accumulation of histologically verified

The lung ultrasound examination can be performed using any commercially available two-dimensional (2D) scanner (cardiac, convex, microconvex, or linear probe), also portable, with any transducer frequency. Higher frequencies, as in linear probes, are useful for the evaluation of the pleura, but provide a worse definition of the pulmonary parenchyma. There is no need for a second harmonic or Doppler imaging mode. The examinations are performed with patients in a near-supine, supine, sitting, or even standing position, as clinically indicated. Two main approaches to LUS should be considered—one for diagnosis and one for semiquantification and follow-up. In patients admitted to the emergency department, for a prompt diagnosis, LUS can be focused on eight areas, two anterior and two lateral per side.5 When the assessment is focused on the evaluation of pulmonary congestion, in order to achieve a semiquantification that may help for follow-up and prognostic stratification, it would be appropriate to use the scheme shown in Figure 82.4.7 Ultrasound scanning of the anterior and lateral chest is obtained on the right and left hemithorax, from the second to the fourth (on the right side to the fifth) intercostal spaces, and from the parasternal line to the axillary line. The sum of the B-lines found on each scanning site yields a score denoting the extent of extravascular fluid in the

1984


Fig. 82.4: Thoracic scanning areas for semiquantitative assessment of B-lines. Source: Modified from Jambrik et al. 2004.

lung. Zero is defined as a complete absence of B-lines in the investigated area. For clinical purposes, B-lines may be semiquantified from mild to severe degree, similar to what is done for most echocardiographic parameters.10 B-lines have a very satisfactory intraobserver and interobserver variability, consistently < 10%.7

PULMONARY INTERSTITIAL EDEMA Diagnosis The possibility of detecting pulmonary edema before it becomes clinically apparent is so inherently attractive that the effort to develop and validate such a technique still continues after many years of tireless and relatively unrewarding attempts.11 Chest X-ray remains by far the best and most frequently used screening test for the detection of pulmonary edema, but is difficult to interpret and is imprecise, with high interobserver variability.12 The absence of chest X-ray findings does not exclude the presence of a high pulmonary capillary wedge pressure (PCWP) > 30 mm Hg. According to American Heart Association/American College of Cardiology guidelines, serial chest radiographs are not recommended in the assessment of pulmonary congestion in chronic heart failure (HF), since they are too insensitive to detect all but the most extreme changes in the fluid status. Direct measurement of PCWP via catheterization is the “gold standard” to evaluate hemodynamic congestion, but its invasive nature limits clinical utility. Thus, because current

technology for measuring lung edema can be inaccurate (chest X-ray), cumbersome (nuclear medicine and radio logy techniques), or invasive (indicator dilution), there is great potential for a technology that could quantify lung edema noninvasively in real time with a radiation-free and portable method. Being a sign of pulmonary congestion, B-lines are useful for the identification of cardiogenic versus noncar diogenic dyspnea in an acute setting,13 with an accuracy comparable to that of natriuretic peptides.14–16 B-lines could be a plausible alternative, especially in emergency depart ments where natriuretic peptide analysis is not available, and could aid diagnosis in cases where natriuretic peptide levels are in the “gray zone,” and positive predictive value is not very high, especially in patients with renal failure.

Treatment The recognition, quantification, and monitoring of pulm onary congestion is important for clinicians at all stages of care of the HF patient. Accurate assessment of effectiveness of medical treatment in reducing pulmonary congestion is mandatory in these patients. Chest X-ray remains by far the best and most frequently used screening test for the detection and in-hospital follow-up of pulmonary congestion, although showing the previously mentioned limitations. Another way to monitor congestion is through monitoring body weight. However, this has limited reliability as a predictor of congestion status, since body


weight does not take into account systemic water, weight gain may reflect normal fluctuations in time, and weight loss due to loss of muscle/fat (cardiac cachexia) may obscure increased fluid retention.17 B-lines have already been proposed as a bedside, easyto-use alternative diagnostic tool for clinically monitoring pulmonary congestion in patients with HF.18 The sign is very dynamic, as shown by rapid increase after exercise, in patients with and without left ventricular dysfunction.19 B-lines are well-related to the degree of dyspnea: the number of B-lines increases, as the degree of dyspnea worsens.20 Since B-lines can be dissolved in a few minutes by an acute diuretic load, they may be a useful bedside tool for monitoring diuretic therapy response, in a real time fashion.8,18 The simplicity and low-tech nature of this examination also makes it appealing for out-of-hospital office monit oring of HF patients; there would be the possibility of tailoring pharmacological therapy as soon as the patient, although asymptomatic, shows echographic signs of pulmonary congestion, in order to avoid new hospita lizations for worsening dyspnea, which would likely appear with some days of delay.21 The possibility of assessing B-lines with light, portable, hand-held devices could also allow a cardiologist to evaluate the degree of decompensation directly at the patient’s home.3

Prognosis Persistent hemodynamic congestion that is not adequately recognized and treated before discharge is associated with adverse clinical outcome in HF patients; on the other hand, postdischarge freedom from pulmonary congestion is associated with a better prognosis.22 It has been shown that in patients admitted to the hospital with dyspnea and/ or chest pain, the presence of B-lines identifies a subgroup at a higher risk of experiencing events—the higher the number of B-lines, the worse the outcome. The 16-month event-free survival showed a significantly better outcome for those patients without B-lines, whereas a worse outcome was observed in patients with a severe grade of B-lines (total number > 30). In regard to future HF hospitalization alone, and not as part of the combined endpoint, the rate of new hospitalization for progression of HF was higher in patients with a severe B-line score and lower in patients with no B-lines (log rank = 24.4, P < 0.0001).23 These data have also been confirmed in a multicentric study on a large number of patients on hemodialysis.24

1985

PLEURAL EFFUSION Detection of pleural effusion (PE) is the more established application of LUS.1 PE can be easily detected directly through the intercostal spaces with either a cardiac or convex probe. The effusion should first be sought in dependent zones, that is, lateral and posterior chest. It rules out other etiologies such as atelectasis, consolidation, mass, or an elevated hemidiaphragm. It takes less time than radiographic methods and can be repeated serially at the bedside. Ultrasound images PE as an anechoic or hypoechoic space between two pleural layers. The lung behind a PE appears either aerated or consolidated in the case of large PE. In critically ill patients, LUS is especially valuable, showing better sensitivity and reliability than bedside chest X-ray for the diagnosis of PE.25,26 Bedside chest X-ray rarely detects small effusions and can also miss effusions of up to 500 mL.27 For the detection of PE, with computed tomography (CT) as a gold standard, sensitivity and specificity of ultrasound are 93%.27 Minimal effusions can be detected using ultrasound, provided the probe is applied over an adequate area of the chest. Ultrasound can detect the effusion, evaluate its volume, provide information on its nature, and indicate the appropriate area for an eventual thoracocentesis. Ultrasound is acknowledged as the method of choice for detecting an effusion in a supine patient.

PULMONARY EMBOLISM The diagnosis of pulmonary embolism has always been a considerable challenge and requires a high index of clinical suspicion from the emergency physician. In addition, diagnosing pulmonary embolism may require the use of one or more direct and indirect diagnostic methods. Most lesions related to pulmonary embolism are localized in the lower lobes of the lung and are often associated with an area of pleuritic chest pain. These processes essentially involve the terminal air spaces and result in the evacuation of air from the affected parenchymal area, creating an “ultrasonic window” and allowing ultrasound waves to travel further into the lung. The characteristic sonographic findings in pulmonary embolism are multiple, hypoechoic, pleural-based parenchymal lesions which adopt a wedge shape.28 These lesions can be visualized at least in three fourths of cases.29 The accuracy of LUS for the detection of pulmonary embolism was found to be 84% at a prevalence of 55% in a large multicenter study series comprising 352 patients with suspected pulmonary embolism.30

1986


Fig. 82.5: Small subpleural consolidations and multiple B-lines in a typical sonographic pattern of ALI/ARDS.

In combination with echocardiography and leg vein compression sonography, the accuracy of LUS is >90%.31 In order to be detectable by LUS, the lesions need to extend to the pleural surface, which is usually the case. In addition, mechanical alterations associated with consolidated lung tissue, increased capillary pressure, and permeability, due to the release of inflammatory mediators, also cause increased exudation of fluid,28 leading to localized pleural fluid collection adjacent to the affected pulmonary region or presence of localized multiple B-lines. Exploration of the lesions by color Doppler imaging may provide addi tional diagnostic information. In pulmonary infarction, areas of pulmonary arterial flow cannot be detected on color Doppler ultrasound, a phenomenon referred to as “consolidation with little perfusion.”31 On the other hand, recanalization of incomplete infarction resulting from anticoagulation treatment or intrinsic lysis can be demonstrated by the reappearance of a blood flow signal on follow-up. It is important to note that a normal LUS does not exclude the presence of PE.29

ACUTE RESPIRATORY DISTRESS SYNDROME ARDS is a common syndrome of diffuse lung injury and has a high mortality rate.32 In ARDS, LUS provides a sensitivity of 98% and a specificity of 88% in diagnosing the presence of the alveolar-interstitial syndrome as seen at CT, performing better than either auscultation or chest

X-ray.33 Differential diagnosis between acute cardiogenic pulmonary edema and ARDS may often be difficult. The sonographic pattern of multiple diffuse B-lines is present in both conditions. However, there are some clues that may help in the differential diagnosis—pleural line abnormalities, presence of small subpleural consolidations or coarse appearance of the pleural line (Fig. 82.5), “spared areas” defined as areas of normal lung pattern surrounded by areas of multiple B-lines, and lung consolidations are often found in ARDS, but are not present in cardiogenic pulmonary edema.34 B-lines can also identify subclinical pulmonary edema in situations of extreme physiology such as strenuous effort in ordinary conditions (elite apnea divers or triathletes)35,36 or ordinary effort in extreme conditions such as high altitude pulmonary edema in recreational climbers,37 again suggesting that clinical symptoms are only the tip of the iceberg of pulmonary edema, even outside the acute HF syndrome.

PNEUMOTHORAX Pneumothorax (PTX) is a frequent, life-threatening complication in patients who have been admitted to the emergency department. Bedside chest X-ray may mis diagnose up to 30% of cases.38 Radiographically “occult” PTX may rapidly progress to tension PTX if its diagnosis is missed or delayed, especially in patients receiving mechanical ventilation.39 Being a “nondependent” condition, PTX should be sought at first on the anterior and lower areas. Absence of lung sliding is a basic and initial step for the diagnosis, and a striking absence of motion arising from the pleural line is observed instead of the lung sliding.40,41 The presence of lung sliding allows PTX to be confidently discounted because the negative predictive value is 100%.40 The abolition of lung sliding can be objectified in M-mode, which gives a characteristic pattern, the stratosphere sign. However, absent lung sliding does not necessarily mean PTX. Many other situations yield abolished lung sliding, such as high-frequency ventilation, massive atelectasis, pleural adherences, severe fibrosis, and so on.5 The other conditions needed to diagnose PTX by LUS are absence of B-lines—the slightest B-line allows prompt ruling out of PTX.40 The pathognomonic LUS sign of PTX is the lung point, which allows PTX to be confirmed, with a specificity of 100% and sensitivity of about 65%, a percentage that falls with major PTX with complete lung retraction.42


1987

Table 82.1: The Three B-Line Scenarios: Heart Failure, ALI/ARDS, and Interstitial Lung Disease

Clinical Examples

Heart Failure

ALI/ARDS

Pulmonary Fibrosis

EF

Abnormal (decreased)

Normal

Normal

PASP

Abnormal (increased)

Normal

Normal/Increased

Effect of diuresis/dialysis on B-lines

Reduction in minutes–hours

No effect

No effect

Other LUS sign

Pleural effusion

Subpleural alterations

Pleural thickening

Theater

ER/Cardiology/Internal Medicine

Intensive Care

Pulmonology/Internal Medicine

(ALI: Acute lung injury; ARDS: Acute respiratory distress syndrome; EF: Ejection fraction; LUS: Lung ultrasound scan; PASP: Pulmonary artery systolic pressure).

CARDIOPULMONARY ULTRASOUND: AN INTEGRATED APPROACH Echocardiography is an essential tool for the management of patients with heart disease, providing an enormous amount of information on both acute and chronic condi tions. The addition of LUS to echocardiography provides an additive insight into the presence of EVLW or any other pulmonary involvement. Presence of multiple, diffuse, bilateral B-lines associated with left ventricular systolic and/or diastolic dysfunction or valvular heart disease is highly suggestive of cardiogenic pulmonary congestion. Moreover, for any given level of cardiac dysfunction, the response of the pulmonary vascular bed may be variable. LUS helps identify those patients who, although asymptomatic, are going to decompensate and require more aggressive treatment.43,44 Presence of multiple, diffuse, bilateral B-lines, associated with a normal heart, indicates a noncardiac cause of pulmonary edema such as acute lung injury (ALI)/ARDS or interstitial pneumonia. Alternatively, especially in a chronic setting, it should prompt the suspicion of pulmonary fibrosis. It is important to distinguish the multiple, diffuse, bilateral B-line pattern from focal multiple B-lines, which can be present in normal lungs or may be seen in the context of many pathological conditions such as lobar pneumonia, pulmo nary contusion, pulmonary infarction, pleural disease, and neoplasia. This further underlines the importance of integrating LUS findings with the patients’ history, clinical presentation, and other instrumental data. An example of the integration between clinical, echocardiography, and lung ultrasound information for the differentiation of the three main scenarios of B-lines in HF, ALI/ARDS, and interstitial lung disease is reported in Table 82.1.

LUS is one of the easiest applications of echography, much easier than echocardiography. Image patterns are readily teachable, and minimal didactic and image recognition skill sessions are needed.3,45 The learning curve for B-line evaluation and grading is very short. The complement of LUS to echocardiography would require only a few minutes in addition to the time needed for a resting echocardiogram.

LIMITATIONS LUS limitations are essentially patient-dependent. Obese patients may be more difficult to examine due to the thickness of their rib cage and soft tissues. The presence of subcutaneous emphysema or large thoracic dressings alters or precludes the propagation of the ultrasound beams to the subpleural lung parenchyma. The main limitation of B-line interpretation is the lack of specificity. As previously mentioned, they are a sign of interstitial syndrome; therefore, they are a very sensitive but not specific sign of cardiogenic pulmonary edema. How to distinguish the different etiologies of B-lines has been discussed in this chapter. However, it must be emphasized that LUS does not rule out pulmonary abnormalities (especially consolidations) that do not reach the pleura. In the next few years, LUS is likely to become an extension of physical examination in many different clinical settings, from the emergency department to the intensive care unit, from cardiology to pulmonology, and nephrology wards and dialysis units.

REFERENCES 1. Longo D, Fauci AS, Kasper DL, et al. Harrison’s Principles of Internal Medicine. 18th ed. New York: McGraw-Hill; 2011.

1988


2. Moore CL, Copel JA. Point-of-care ultrasonography. N Engl J Med. 2011;364(8):749–57. 3. Bedetti G, Gargani L, Corbisiero A, et al. Evaluation of ultrasound lung comets by hand-held echocardiography. Cardiovasc Ultrasound. 2006;4:34. 4. Soldati G, Copetti R, Sher S. Sonographic interstitial syndrome: the sound of lung water. J Ultrasound Med. 2009; 28(2):163–74. 5. Volpicelli G, Elbarbary M, Blaivas M, et al; International Liaison Committee on Lung Ultrasound (ILC-LUS) for International Consensus Conference on Lung Ultrasound (ICC-LUS). International evidence-based recomme ndations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577–91. 6. Gargani L, Doveri M, D’Errico L, et al. Ultrasound lung comets in systemic sclerosis: a chest sonography hallmark of pulmonary interstitial fibrosis. Rheumatology (Oxford). 2009;48(11):1382–7. 7. Jambrik Z, Monti S, Coppola V, et al. Usefulness of ultrasound lung comets as a nonradiologic sign of extravascular lung water. Am J Cardiol. 2004;93(10):1265–70. 8. Picano E, Gargani L. Ultrasound lung comets: the shape of lung water. Eur J Heart Fail. 2012;14(11):1194–6. 9. Gargani L, Lionetti V, Di Cristofano C, et al. Early detection of acute lung injury uncoupled to hypoxemia in pigs using ultrasound lung comets. Crit Care Med. 2007;35(12): 2769–74. 10. Picano E, Frassi F, Agricola E, et al. Ultrasound lung comets: a clinically useful sign of extravascular lung water. J Am Soc Echocardiogr. 2006;19(3):356–63. 11. Lange NR, Schuster DP. The measurement of lung water. Crit Care. 1999;3(2):R19–24. 12. Nieminen MS, Böhm M, Cowie MR, et al; ESC Committee for Practice Guideline (CPG). Executive summary of the guidelines on the diagnosis and treatment of acute heart failure: the Task Force on Acute Heart Failure of the European Society of Cardiology. Eur Heart J. 2005;26(4):384–416. 13. Lichtenstein D, Mezière G. A lung ultrasound sign allo wing bedside distinction between pulmonary edema and COPD: the comet-tail artifact. Intensive Care Med. 1998;24(12):1331–4. 14. Gargani L, Frassi F, Soldati G, et al. Ultrasound lung comets for the differential diagnosis of acute cardiogenic dyspnoea: a comparison with natriuretic peptides. Eur J Heart Fail. 2008;10(1):70–7. 15. Liteplo AS, Marill KA, Villen T, et al. Emergency thoracic ultrasound in the differentiation of the etiology of shortness of breath (ETUDES): sonographic B-lines and N-terminal pro-brain-type natriuretic peptide in diagnosing congestive heart failure. Acad Emerg Med. 2009;16(3):201–10. 16. Prosen G, Klemen P, Štrnad M, et al. Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting. Crit Care. 2011;15(2):R114.

17. Chaudhry SI, Wang Y, Concato J, et al. Patterns of weight change preceding hospitalization for heart failure. Circulation. 2007;116(14):1549–54. 18. Volpicelli G, Mussa A, Garofalo G, et al. Bedside lung ultrasound in the assessment of alveolar-interstitial syndrome. Am J Emerg Med. 2006;24(6):689–96. 19. Agricola E, Picano E, Oppizzi M, et al. Assessment of stressinduced pulmonary interstitial edema by chest ultrasound during exercise echocardiography and its correlation with left ventricular function. J Am Soc Echocardiogr. 2006;19(4):457–63. 20. Frassi F, Gargani L, Gligorova S, et al. Clinical and echocar diographic determinants of ultrasound lung comets. Eur J Echocardiogr. 2007;8(6):474–9. 21. Yu CM, Wang L, Chau E, et al. Intrathoracic impedance monitoring in patients with heart failure: correlation with fluid status and feasibility of early warning preceding hospitalization. Circulation. 2005;112(6):841–8. 22. Gheorghiade M, Filippatos G, De Luca L, et al. Congestion in acute heart failure syndromes: an essential target of evaluation and treatment. Am J Med. 2006;119(12 Suppl 1): S3–10. 23. Frassi F, Gargani L, Tesorio P, et al. Prognostic value of extravascular lung water assessed with ultrasound lung comets by chest sonography in patients with dyspnea and/ or chest pain. J Card Fail. 2007;13(10):830–5. 24. Zoccali C, Torino C, Tripepi R, et al.; Lung US in CKD Working Group. Pulmonary congestion predicts cardiac events and mortality in ESRD. J Am Soc Nephrol. 2013; 24(4):639–46. 25. Eibenberger KL, Dock WI, Ammann ME, et al. Quantification of pleural effusions: sonography versus radiography. Radiology. 1994;191(3):681–4. 26. Balik M, Plasil P, Waldauf P, et al. Ultrasound estimation of volume of pleural fluid in mechanically ventilated patients. Intensive Care Med. 2006;32(2):318–21. 27. Roch A, Bojan M, Michelet P, et al. Usefulness of ultrasono graphy in predicting pleural effusions > 500 mL in patients receiving mechanical ventilation. Chest. 2005;127(1): 224–32. 28. Reissig A, Heyne JP, Kroegel C. Sonography of lung and pleura in pulmonary embolism: sonomorphologic characterization and comparison with spiral CT scanning. Chest. 2001;120(6):1977–83. 29. Mathis G. Chest Sonography. 2nd ed. Berlin: Springer Verlag; 2008. 30. Mathis G, Blank W, Reissig A, et al. Thoracic ultrasound for diagnosing pulmonary embolism: a prospective multi center study of 352 patients. Chest. 2005;128(3):1531–38. 31. Yang PC. Color Doppler ultrasound of pulmonary consoli dation. Eur J Ultrasound. 1996;3:169–78. 32. Ware LB, Matthay MA. The acute respiratory distress synd rome. N Engl J Med. 2000;342(18):1334–49. 33. Lichtenstein D, Goldstein I, Mourgeon E, et al. Comparative diagnostic performances of auscultation, chest radiography, and lung ultrasonography in acute respiratory distress syndrome. Anesthesiology. 2004;100(1):9–15.


34. Copetti R, Soldati G, Copetti P. Chest sonography: a useful tool to differentiate acute cardiogenic pulmonary edema from acute respiratory distress syndrome. Cardiovasc Ultrasound. 2008;6:16. 35. Frassi F, Pingitore A, Cialoni D, et al. Chest sonography detects lung water accumulation in healthy elite apnea divers. J Am Soc Echocardiogr. 2008;21(10):1150–5. 36. Pingitore A, Garbella E, Piaggi P, et al. Early subclinical increase in pulmonary water content in athletes performing sustained heavy exercise at sea level: ultrasound lung comet-tail evidence. Am J Physiol Heart Circ Physiol. 2011;301(5):H2161–7. 37. Pratali L, Cavana M, Sicari R, et al. Frequent subclinical high-altitude pulmonary edema detected by chest sonography as ultrasound lung comets in recreational climbers. Crit Care Med. 2010;38(9):1818–23. 38. Chiles C, Ravin CE. Radiographic recognition of pneum othorax in the intensive care unit. Crit Care Med. 1986;14(8):677–80. 39. Bridges KG, Welch G, Silver M, et al. CT detection of occult pneumothorax in multiple trauma patients. J Emerg Med. 1993;11(2):179–86.

1989

40. Lichtenstein DA, Menu Y. A bedside ultrasound sign ruling out pneumothorax in the critically ill. Lung sliding. Chest. 1995;108(5):1345–8. 41. Kirkpatrick AW, Sirois M, Laupland KB, et al. Hand-held thoracic sonography for detecting post-traumatic pne umothoraces: the Extended Focused Assessment with Sono graphy for Trauma (EFAST). J Trauma. 2004;57(2):288–95. 42. Lichtenstein D, Mezière G, Biderman P, et al. The “lung point”: an ultrasound sign specific to pneumothorax. Inte nsive Care Med. 2000;26(10):1434–40. 43. Picano E, Gargani L, Gheorghiade M. Why, when, and how to assess pulmonary congestion in heart failure: pathophy siological, clinical, and methodological implications. Heart Fail Rev. 2010;15(1):63–72. 44. Gargani L. Lung ultrasound: a new tool for the cardiologist. Cardiovasc Ultrasound. 2011;9:6. 45. Noble VE, Lamhaut L, Capp R, et al. Evaluation of a tho racic ultrasound training module for the detection of pneumothorax and pulmonary edema by prehospital physician care providers. BMC Med Educ. 2009;9:3.

CHAPTER 83 The Future of Echocardiography and Ultrasound David Cosgrove

Snapshot ¾¾ Plane Wave Ultrafast Imaging ¾¾ Trends in Scanners ¾¾ Doppler ¾¾ Microbubbles

¾¾ Elastography ¾¾ Light and Sound ¾¾ Therapeutic Applications of Ultrasound

INTRODUCTION Ultrasound has shown a remarkable ability to evolve and even revolutionize, thanks to the efforts of research laboratories and commercial companies around the world. Unlike some industries, ideas developed in one quarter find their way into clinical scanners surprisingly rapidly, to the benefit of our patients. Here, some of the more exciting and intriguing developments and prospects are briefly covered, but it should be borne in mind that the most important innovations may well be unpredictable: expect the unexpected!

PLANE WAVE ULTRAFAST IMAGING A major trend in ultrasound imaging is likely to be the implementation of plane wave imaging1 (Fig. 83.1). This approach, first mooted in the 1980s, radically changed the way scanning is performed.2 Instead of transmitting a series of focused ultrasound beams one by one, the transmitted ultrasound is unfocused, all the elements being activated at once. All the focusing is performed on receive, ideally using software-driven systems. The potential penalty in spatial resolution is more than made for by the huge increase in frame rate (up to 20,000 fps, depending on the required depth) so that multiple pulses can be sent, for example, for compounding, while still retaining very

Fig. 83.1: Ultrafast plane wave imaging. The left image shows a transverse section of a rat brain, measuring about 1 cm across, imaged with the conventional pulse-echo technique. Spatial resolution is greatly increased by using plane wave imaging, shown on the right, in which multiple interrogation at a different angle of insonation (compounding) has been used. Source: Redrawn with permission from Mace E, Montaldo G, Cohen I, et al. Functional ultrasound imaging of the brain. Nat Methods. 2011;8(8):662–4.

high frame rates. The images are crisper because the transmission is so rapid that any motion-induced blurring is “frozen”; this is likely to be especially important in cardiology and particularly for the fetal heart. Doppler

Chapter 83: The Future of Echocardiography and Ultrasound

1991

Fig. 83.2: Ultrafast Doppler. A series of transverse sections of a rat brain using directional power Doppler at an acquisition rate of 20,000/s. The method allows changes in cerebral blood flow to be displayed after brain stimulation in the same way as functional MRI. Source: Redrawn with permission from Tanter M.

Fig. 83.3: Smartphone ultrasound system. This USB-based scanner from Mobisante uses a Smartphone to create ultrasound images. The implications for usage and training are major. http:// www.mobisante.com/product-overview/

could also benefit3 (Fig. 83.2) as could elastography4 and contrast studies could take advantage of the overall lower peak power (since there is no transmit focusing) which could reduce bubble destruction. In addition, the possibility of using extended multipulse methods could improve tissue suppression. The reason for the slow implementation of what seems like an obvious way to exploit one of the strengths of ultrasound, its speed, has been computing limitations. Handling the huge amount of data and capturing and processing the radio frequency (RF) data from over 100 elements at such high data rates was impossible when the approach was first suggested. With the startling speed bumps that the industry has experienced and with the addition of fast graphics chips (stimulated by the computer gaming industry), this limitation has been rolled back and partial implementations have appeared in clinical scanners. Much further development can be expected.

training and embodies a cruel conundrum: less skilled users need the best image quality, and this is denied them. They raise concerns for the quality of diagnoses and possible legal consequences. They could also exacerbate the great harm that ultrasound has delivered in some developing countries: informing on the gender of the fetus so that females can be selectively aborted, a human disaster of unprecedented scale. Indeed, it could be argued that, on account of this, ultrasound has done more harm than good worldwide.6 Increasingly, software-driven scanners can be expected to predominate, at least at the mid- and high end, with fast computing and graphics cards replacing fixed function chips for greater flexibility, upgradability and advantages in servicing. This could result in price reductions, though there has been no sign of this to date. They are also expected to form the platform for plane wave (ultrafast) imaging. Always the key component of an ultrasound system, transducers are being improved, chiefly with the intro duction of single crystal piezoelectric materials.7 These are grown rather like a silicon chip, rather than being a ceramic that requires firing, as is used in conventional piezo materials. Single crystals have better sensitivity on both transmit and receive, and wider bandwidths, so that they can operate over wider frequency ranges, meaning that one probe can work over a wider range of applications. This could be especially important in contrast-enhanced

TRENDS IN SCANNERS Miniaturization is well under way, with laptops and even smart phones being used, if only for display5 (Fig. 83.3). These devices are likely to find their way into every clinician’s white coat pocket, supplementing or even replacing their stethoscopes. This degree of miniatu rization comes at a cost: their image quality cannot rival that of high-end systems. This puts an extra burden on

1992


Fig. 83.4: Live/real time three- and four-dimensional transesophageal echocardiography. En face view of paravalvular mitral prosthetic regurgitation, oriented to be identical to the surgical view. The paravalvular (P) defect is localized at 5 o’clock position in this patient with a metallic prosthesis. (AO: Aorta; LAA: Left atrial appendage; MVR: Mitral valve replacement). Source: Reproduced with permission from Singh P, Manda J, Hsiung MC, et al. Live/real time three-dimensional transesophageal echocardiographic evaluation of mitral and aortic valve prosthetic paravalvular regurgitation. Echocardiography 2009;8:980–7.

Fig. 83.5: Acoustic structure quantification of the liver. This form of tissue characterization looks at the B-mode structure, working in the radio frequency (RF) domain, to assess the image texture. The result is a moving image in which uniform structures are displayed in blue or green, and heterogeneous structures, here exemplified by the walls of blood vessels, are depicted as orange and red. It is likely to be of most value in the liver for assessing steatosis (very uniform) or severe fibrosis and cirrhosis.

ultrasound (CEUS) where higher harmonics need to be detected. Their efficiency is also key to the development of cable-free transducer systems: adequate battery life depends on highly efficient transduction. There is also a move to replace the lead in Lead zirconate titrate (PZT) transducers by less toxic elements such as barium, driven by concerns over the potential toxicity of lead in discarded transducers.8 One transducer trend that, sadly, seems to have stalled is the capacitance micro-machined ultrasound transducer (cMUT); these tiny electrostatic transducers are formed by silicon etching using a photographic mask, just as for a semiconductor chip, but are built with an air gap between two electrodes.9 When an electric charge is placed across the gap, the plates are attracted (or repelled, depending on the charge direction) and the plates move closer together (or further apart), exactly as in an electrostatic loudspeaker. The symmetrical effect on receipt of an acoustic signal allows them to act as both receivers and transmitters. Each element is only a millimeter or so in size and so a matrix of many thousands is needed. An advantage is that once the photo mask has been created, they can be made in large numbers in the same way as silicon chips, and they could therefore become cheap and even disposable (of interest for intravascular ultrasound). It is also possible to build

semiconductors onto the back of the cMUT, operating as preamplifiers, for example. Prototypes have been built, but the field seems to have gone into abeyance. Ways to cut conventional PZT arrays into two-dimen sional matrices containing thousands of elements have been developed.10 These engineering wonders pose a major challenge in cabling and in handling the huge amount of data they generate, but they make possible threedimensional (3D) and four-dimensional (4D) transducers that have been especially promising in echocardiography (Fig. 83.4) and may eventually develop into the standard way to perform ultrasound examinations by replacing the bulky hybrid electromechanical probes that are widely available. Analysis of the B-mode signal content historically formed the basis for ultrasound tissue characterization, a subject that had a vogue but lost its momentum. Interest has now been rekindled because the capacity to work with RF or raw data has arisen with continuing improvements in computing power and data storage and the annual Tissue Characterization Conference has regained popularity.11 There are also commercial implementations that either map tissue texture [e.g. Toshiba’s Acoustic Structure Quantification, ASQ12 (Fig. 83.5)] or look at aspects of the frequency spectrum of the echoes (e.g. Histoscanning).13


1993

interrogated from several angles. The computer can then correct the result for the beam-to-vessel angle. This approach can be done with ultrafast imaging, the rapidly acquired data being reviewed in slow motion so that spectral measurements can be made postacquisition.16 In a smart innovation, another approach is to make use of the lateral modulation that is conventionally ignored to gather data about both inline and across-line Doppler shifts.17 The resulting color Doppler real time display is direction independent, with vector arrows to indicate the flow direction. It is particularly useful for tortuous vasculature, though the method works less well for deeper vessels.

MICROBUBBLES Fig. 83.6: Fusion imaging. In order to biopsy this liver lesion, a previously acquired computed tomography (CT) scan has been entered into the scanner’s memory and the two image sets aligned using a position sensor attached to the ultrasound probe. The lesion is highlighted in a green circle. This allows the complete cross-sectional images of CT to be synchronized with the ultrasound images and the latter used for improved targeting of needles for biopsy and interstitial therapy.

An important trend, especially for interventional work, is fusion imaging, which combines the advantages of the complete cross-sectional display of computed tomography (CT) and magnetic resonance (MR) with the real time interactiveness of ultrasound14 (see Fig. 83.6). In this approach, a 3D data set from a CT or MR scan is imported into the ultrasound system; the probe is attached to an electromagnetic position sensor and its position in space is linked to the cross-sectional imaging, which is then resliced and adjusted to match the ultrasound images. This allows a needle or ablation antenna to be positioned using ultrasound together with the CT or MR data. A redesign of the scanner user interfaces to improve cleanliness by replacing the current button and knobdriven panels with flat wipe-down control surface would be especially important in sensitive environments where microbial contamination is to be avoided (e.g. intrao perative ultrasound).15 It would necessitate a radical rethink but the benefits could be wide ranging.

DOPPLER Doppler has lagged behind until recently. However, the development of methods to mitigate its angle depen dence should simplify its routine use. One method uses compounding, so that each pixel or range gate is

The available microbubbles for ultrasound contrast have excellent properties and, with microbubble-specific multipulse techniques at low mechanical index (MI), give good enhancement of both the macro- and microvascular systems; it has become routine for characterization of focal liver lesions (Figs. 83.7A to C), for endocardial border detection, and is also widely used for assessing myocardial perfusion.18–20 Many innovative applications are being developed, including administration into other body cavities and even intradermal injection for ultrasound lymphangiography (Fig. 83.8). However, there remains a huge potential for further development, both for diagnostic and for therapeutic purposes. There is much preclinical work on targeted microbubbles, mainly directed to the endothelium, the first cell membrane encountered after intravenous injection.21 Three main directions have emerged: targeting activated endothelium as a means to image acute inflammation, targeting neovascularization as a means to image the new vessels in tumors, atheroma and chronic inflammation and targeting thrombus, all forms of molecular imaging.22 The first human studies with a microbubble targeted to VEG-F2 have begun addressing the need for better imaging of prostate cancer, with promising results.23 One of the difficulties has been the choice of ligand: the conventional streptavidin-biotin linker is highly effective but is antigenic, so not suitable for human use. For the VEG-F2 study, Bracco developed a peptide linker that seems to be well tolerated, and there are also maleamide linkers that may prove clinically useful. This target is restricted to the vascular space and the endothelium because microbubbles are too large to penetrate into the interstitium, even when it is leaky, as occurs in tumors. So there has been much interest in

1994


A

C

B

Figs 83.7A to C: Liver metastasis. This lesion in the inferior border of the liver is indeterminate on B-mode ultrasound (arrow in A) despite the presence of scanty power Doppler signals. Following intravenous (IV) administration of a 1.2-mL dose of the microbubble SonoVue, there is enhancement in the arterial phase at 39 s (B) followed shortly by washout in the late phase at 1 min 07 s (C), seen as an increase and then a reduction in the goldcolored signals in the left pane. These hemodynamic features are characteristic of malignancy, in this case, metastatic disease.

Fig. 83.8: Sentinel lymph node—microbubble lymphangiography. In this patient with an invasive breast carcinoma, a small amount (0.4 mL) of SonoVue was injected intradermally in the periareaolar tissue and the draining lymphatic (seen here as a green curved line in the left-hand panel) traced to the sentinel lymph node (arrow), which was then biopsied. The method could improve preoperative staging in these patients and avoid the need for frozen section microscopy in theater, thus reducing the need for repeat surgery when this is falsely negative, as occurs in up to 25% of cases.

developing particles24 (actually condensed microbubbles with no gas) that are both small enough to do so and can be re-activated to form microbubbles by sonication once they have reached the desired tissue space or target.

ELASTOGRAPHY A special opportunity to examine the mechanical properties of human tissue has been the development


1995

Fig. 83.9: Strain elastography. This breast carcinoma shows as a predominantly blue (indicating hard) region in the elastogram, shown in the left panel. Regions of interest can be placed over the surrounding fat and over the lesion to derive a strain ratio, here calculated at 3.37, indicating a stiff lesion.

Fig. 83.10: Shear wave elastography. A scirrhous breast cancer shows as a shadowing mass on B-mode in the lower panel. The shear wave elastogram in the upper panel shows it to be very stiff (red colors) especially in the periphery where values of 225 kPa were measured. This system uses ultrafast plane wave imaging to capture the shear wave at sufficient speed that real time imaging is possible.

of elastography.25–27 Tissue stiffness derives from the interlinks between tissue structures, especially connective tissues (and ultimately, bone, though this is not amenable to ultrasonic interrogation), and this is quite different to the structures that support the longitudinal waves of conventional ultrasound. The attraction of elastography is the huge range of tissue stiffness and the marked changes that occur with pathology, malignancies, for example, being stiffer than the host tissue. Two ways to image the elastic properties of tissue have been developed: strain and shear wave approaches. In strain elastography, the longer established of the two, the tissue is displaced, usually by gentle probe pressure, and the way it deforms is measured by tracking the changes in the speckle pattern using conventional ultrasound (Fig. 83.9). Softer tissues displace more, harder tissues less, and a color overlay indicating their relative stiffness can be created. Shear waves are transverse, slow-moving waves that are generated by any body movements. Their speed is proportional to the tissue’s stiffness. The commonest way to generate shear waves is to use acoustic radiation force impulses (ARFIs) with high MI ultrasound push pulses that are akin to those used in Doppler. The resulting shear waves travel at right angles to the push beam and their speed can be measured using conventional or plane wave ultrasound (Fig. 83.10). The shear wave method has advantages of being applicable in any organ that is ultrasound-accessible (strain elastography is hard

to use for the heart or abdominal organs) and of being quantitative, with readouts in meters per second (m/s) that can be converted to kilopascals (kPa), the standard unit for elasticity. Much work has been done in refining the classification of malignancies in the breast, thyroid, and prostate and for assessing liver fibrosis; in this application, it is beginning to reduce the need for liver biopsies. The mechanical properties of body tissues are extre mely complex and elasticity also includes a viscosity component (tissue is stiffer when distorted rapidly) as well as porosity (exemplified by pitting edema). Some of these might be amenable to elastography approaches. The viscosity component results in a spread of the frequencies of shear waves and measuring this is feasible and could provide a key to evaluating steatosis of the liver.28

LIGHT AND SOUND If a laser pulse is focused into soft tissue, the local heating causes expansion which releases an ultrasound pulse that can be detected at the body surface, a process known as photoacoustic imaging.29 Tissue strongly attenuates most light wavelengths (it is opaque to most colors of light) but infrared and near-infrared light can penetrate for a centimeter or so. It is strongly absorbed by hemoglobin and melanin (endogenous absorbers), and injected dyes can extend these effects. The precision of the laser

1996


pulses gives excellent spatial resolution and both single ultrasound transducers (with CT-like repositioning) and arrays have been used to image blood vessels, melanomas, and myocardial infarctions in small animals. Extension to superficial tissues in man seems possible. The complementary approach, acousto-optical ima ging, relies on the fact that the beam of a laser light passing through a semi-opaque medium such as tissue is diffracted when the material is agitated by a traversing ultrasound beam. A classic implementation is the Schlieren tank used to visualize the beam from an ultrasound transducer and the same principle can be used to image tissues and has been applied to small animals.30 In an extension of this method, the arrival time of a shear wave can be measured, and if this is performed at more than one location (e.g. using an array to generate shear waves from different locations), the shear wave speed can be measured with great precision.31

THERAPEUTIC APPLICATIONS OF ULTRASOUND Diagnostic ultrasound is used at low powers, partly with the intention of avoiding heating tissue, but if the power is increased, heating occurs and this has been exploited in physiotherapy. It is also effective for promoting healing of bone fractures and skin ulcers.32 If much higher powers are used, tissue temperatures can be raised to above 55°C and the tissue coagulated.33,34 In this approach, a large transducer with tight focusing concentrates the beam into a volume of about 2 × 10 mm; heating takes a few seconds and then the beam is repositioned to the neighboring location and the steps repeated across the desired volume that needs to be ablated. The process is known as highly focused ultrasound (HIFU) and is widely used, especially in China, to ablate tumors, both benign and malignant as well as for pain control in cancer of the pancreas.35 In many countries, HIFU is officially recommended for prostate disease, both benign hypertrophy and localized cancer. It has the advantage of being noninvasive and very precise: the heat coagulation completely spares tissue only a few cells away from the coagulated region. Its disadvantage is that it is slow, though ways to speed it up are being investigated. Ultrasound is being developed as a means to allow drugs to cross the skin barrier for transdermal drug delivery.36 Low-frequency ultrasound transiently loosens the squamous layer of the epidermis (probably by cavitation) so that even large molecules such as insulin

and heparin can be delivered. This has the potential for continuous administration of these drugs that otherwise must be injected, with the expectation of a bettercontrolled therapeutic effect. The process also works in the opposite direction such that interstitial fluid samples can be obtained for analysis, for example, of glucose levels. Ultimately, the combination could facilitate a feedback loop to maintain excellent round-the-clock blood sugar control. Microbubbles and nanodroplets can have ligands attached and can carry payloads such as nucleic acids37 and chemotherapeutic drugs for targeted delivery, with the expectation that tissue side effects would be minimized. Short of this development, the coadministration of conventional microbubbles and thrombolytic drugs such as tissue plasminogen activator (tPA) and plasmin has been used with sonication of the relevant cerebral artery (usually the middle cerebral, but alternatively the coronaries). Diagnostic ultrasound alone accelerates thrombolysis, but the combination is more effective and clinical trials are underway.38 Remaining problems are the risk of hemorrhagic stroke and the persistence of ischemic damage to the downstream microvasculature. In myocardial infarction, this manifests itself as poor myocardial perfusion at the microvascular level despite restoration of flow in the main coronary arteries. The therapeutic uses of microbubbles and derivatives seem likely to become more important clinically than their diagnostic value.

CONCLUSION The prospects for continued clinically significant develo pments in ultrasonography are strong with many inno vations in the offing. The area continues to surprise us with innovations in diagnostics while therapeutic opportunities are also on the horizon.

REFERENCES 1. Montaldo G, Tanter M, Bercoff J, et al. Coherent plane-wave compounding for very high frame rate ultrasonography and transient elastography. IEEE Trans Ultrason Ferroelectr Freq Control. 2009;56(3):489–506. 2. Shattuck DP, Weinshenker MD, Smith SW, et al. Explo soscan: a parallel processing technique for high speed ultrasound imaging with linear phased arrays. J Acoust Soc Am. 1984;75(4):1273–82. 3. Tanter M, Bercoff J, Sandrin L, et al. Ultrafast compound imaging for 2-D motion vector estimation: application to transient elastography. IEEE Trans Ultrason Ferroelectr Freq Control. 2002;49(10):1363–74.


4. Tanter M, Bercoff J, Athanasiou A, et al. Quantitative assessment of breast lesion viscoelasticity: initial clinical results using supersonic shear imaging. Ultrasound Med Biol. 2008;34(9):1373–86. 5. Kawai J, Tanabe K, Matsuzaki M, et al. [Validation of a new hand-carried ultrasound device equipped with directional color power Doppler and continuous wave Doppler]. J Cardiol. 2003;42(4):173–82. 6. Boughton, J. Female feticide: The ethical issues of ultrasound in India and China. 2013 [cited 2013 06/05.2013]; Available from: http://www.kevinmd.com/blog/2013/05/female-feti cide-ethical-issues-ultrasound-india-china.html. 7. Chen, J, R Panda, and B Savord. PureWave crystal techno logy. 2006; Available from: http://www.healthcare.phi lips.com/pwc_hc/main/shared/Assets/Documents/ Ultrasound/Solutions/technologies/Philips_PureWave_ crystal_technology.pdf. 8. Shrout T, Zhang S. Lead-free piezoelectric ceramics: alter natives for PZT? J Electroceramics. 2007;19(1):113–26. 9. Oralkan O, Ergun AS, Johnson JA, et al. Capacitive micro machined ultrasonic transducers: next-generation arrays for acoustic imaging? IEEE Trans Ultrason Ferroelectr Freq Control. 2002;49(11):1596–610. 10. Yu Z, Blaak S, Chang ZY, et al. Front-end receiver electr onics for a matrix transducer for 3-D transesophageal echocardiography. IEEE Trans Ultrason Ferroelectr Freq Control. 2012;59(7):1500–12. 11. Linzer, M. UITC Symposium. 2013; Available from: http:// uitc-symposium.org/index.html. 12. Kuroda H, Kakisaka K, Kamiyama N, et al. Non-invasive determination of hepatic steatosis by acoustic structure quantification from ultrasound echo amplitude. World J Gastroenterol. 2012;18(29):3889–95. 13. Braeckman J, Autier P, Garbar C. Computer-aided ultraso nography (HistoScanning): a novel technology for locating and characterizing prostate cancer. BJU Int. 2007. 14. Sandulescu DL, Dumitrescu D, Rogoveanu I, et al. Hybrid ultrasound imaging techniques (fusion imaging). World J Gastroenterol. 2011;17(1):49–52. 15. Sykes A, Appleby M, Perry J, et al. An investigation of the bacteriological contamination of ultrasound equipment. Br L Infect Control. 2006;7(4):16–20. 16. Osmanski BF, Pernot M, Montaldo G, Bel A, Messas E, Tanter M. Ultrafast Doppler imaging of blood flow dyna mics in the myocardium. IEEE Trans Med Imaging. 2012; 31(8):1661–8. 17. Evans DH, Jensen JA, Nielsen MB. Ultrasonic colour Doppler imaging. Interface Focus. 2011;1(4):490–502. 18. Piscaglia F, Nolsøe C, Dietrich CF, et al. The EFSUMB Guidelines and Recommendations on the Clinical Practice of Contrast Enhanced Ultrasound (CEUS): update 2011 on non-hepatic applications. Ultraschall Med. 2012;33(1): 33–59. 19. Claudon M, Dietrich CF, Choi BI, et al; World Federation for Ultrasound in Medicine; European Federation of Societies for Ultrasound. Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver—update 2012: A WFUMB-EFSUMB

1997

initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS. Ultrasound Med Biol. 2013;39(2):187–210. 20. NICE, dg. SonoVue (sulphur hexafluoride microbubbles)— contrast agent for contrast- enhanced ultrasound imaging of the liver. 2012. 21. Pochon S, Tardy I, Bussat P, et al. BR55: a lipopeptide-based VEGFR2-targeted ultrasound contrast agent for molecular imaging of angiogenesis. Invest Radiol. 2010;45(2):89–95. 22. Kiessling F. Science to practice: exploring new indications for molecular US imaging. Radiology. 2013;267(3):661–2. 23. Smeenge M, Mischi M, Laguna Pes MP, et al. Novel contrast-enhanced ultrasound imaging in prostate cancer. World J Urol. 2011;29(5):581–7. 24. Dayton PA, Zhao S, Bloch SH, et al. Application of ultrasound to selectively localize nanodroplets for targeted imaging and therapy. Mol Imaging. 2006;5(3):160–74. 25. Bamber J, Cosgrove D, Dietrich CF, et al. EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 1: Basic principles and technology. Ultraschall Med. 2013;34(2):169–84. 26. Cosgrove D, Piscaglia F, Bamber J, et al. EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 2: Clinical applications. Ultraschall Med. 2013;34(3):238–53. 27. Gennisson JL, Deffieux T, Fink M, et al. Ultrasound elasto graphy: principles and techniques. Diagn Interv Imaging. 2013;94(5):487–95. 28. Song P, Urban M, Manduca A, et al. Comb-push ultrasound shear elastography (CUSE) with various ultrasound push beams. IEEE Trans Med Imaging. 2013.;32(8):1435–47. 29. Lai P, Xu X, Wang LV. Ultrasound-modulated optical tomo graphy at new depth. J Biomed Opt. 2012;17(6):066006. 30. Lerosey G, Fink M. Acousto-optic imaging: merging the best of two worlds. Nature Photonics. 2013;7:265–7. 31. Cheng Y, Li R, Li S, et al. Shear wave elasticity imaging based on acoustic radiation force and optical detection. Ultrasound Med Biol. 2012;38(9):1637–45. 32. Patrick MK. Ultrasound in physiotherapy. Ultrasonics. 1966;4:10–14. 33. Barkin J. HIFU: Definitely ready for prime time. Can Urol Assoc J. 2011;5(6):422–3. 34. Dubinsky TJ, Cuevas C, Dighe MK, et al. High-intensity focused ultrasound: current potential and oncologic applications. AJR Am J Roentgenol. 2008;190(1):191–9. 35. Jang HJ, Lee JY, Lee DH, et al. Current and Future Clinical Applications of High-Intensity Focused Ultrasound (HIFU) for Pancreatic Cancer. Gut Liver. 2010;4 Suppl 1:S57–61. 36. Polat BE, Hart D, Langer R, et al. Ultrasound-mediated transdermal drug delivery: mechanisms, scope, and emerging trends. J Control Release. 2011;152(3):330–48. 37. Koike H, Tomita N, Azuma H, et al. An efficient gene transfer method mediated by ultrasound and microbubbles into the kidney. J Gene Med. 2005;7(1):108–16. 38. Barlinn K, Barreto AD, Sisson A, et al. CLOTBUST-hands free: initial safety testing of a novel operator-independent ultrasound device in stroke-free volunteers. Stroke. 2013;44(6):1641–6.

CHAPTER 84 A Primer on Cardiac MRI for the Echocardiographer Madhavi Kadiyala, Aasha S Gopal

Snapshot  QuanƟtaƟve LeŌ and Right Ventricular Assessment  Strain Assessment  LeŌ Ventricular Structure  MyocardiƟs and Sarcoidosis  Cardiac Hypertrophy  Cardiomyopathies

INTRODUCTION Significant progress has been made in the area of cardiac imaging since the days of M-mode and B-mode echocardiography. Advances in computed tomography (CT) and magnetic resonance imaging (MRI) technology, along with three-dimensional (3D) echocardiography enable the modern cardiologist to make clinical diagnoses with high accuracy and precision. Until recently, myocarditis was a presumptive diagnosis in a patient presenting with elevated cardiac troponins and normal coronary arteries. Today, accurate diagnosis of myocarditis and the extent of myocardial involvement can be made without invasive procedures using cardiac MRI. This chapter discusses the practical applications and limitations of cardiac MRI in various cardiac conditions. A glossary of common cardiac MRI terms is included at the end of this chapter. While echocardiographic imaging is the first line of diagnostic testing for most cardiac conditions, cardiac MRI is valuable, when it is important to assess: 1. Tissue characterization: myocardial infarction, inflammation, and fibrosis 2. Accurate quantitation of cardiac chambers

 Velocity Mapping, Flow and Shunt Assessment  Valvular Heart Disease and ProstheƟc Valves  Pericardial Disease  Normal Variants and Masses  LimitaƟons of Cardiac MRI and CT

3. Cardiac masses and normal structural variants 4. Intracardiac shunts 5. Pericardial pathology. While cardiac MRI can be very useful in many conditions, its value is limited in some situations, for example, patent foramen ovale, small mobile masses such as vegetations, calcium, etc. Flow quantitation in valvular heart disease is also possible. However, only imagers with expertise in this area should interpret this useful technique due to the many limitations of the methodology. Additionally, there are technical and patient-related factors that influence the image quality, thus affecting the overall utility of cardiac MRI. In most situations, since it is the echocardiographer who recommends MRI imaging, it is important to understand the advantages and limitations of cardiac MRI.

QUANTITATIVE LEFT AND RIGHT VENTRICULAR ASSESSMENT Accuracy of echocardiographic quantitation of the left ventricle is highly dependent on the image quality and can be highly variable due to uncertainty of the location of

Chapter 84: A Primer on Cardiac MRI for the Echocardiographer

the imaging plane in 3D space. Cardiac MRI is considered the gold standard for quantitative assessment of the ventricles due to high accuracy and reproducibility in measuring ventricular volumes and ejection fraction. The most common method uses a stack of short-axis images acquired through the body of the ventricles (Fig. 84.1). Analysis is performed using the Simpson’s method, where the endocardial area from each slice is measured and multiplied by the interslice distance. The volumes are traced in end-diastole and end-systole, and ejection fraction is calculated. Automated software packages are available that assist the image analyst in computing accurate volumes and function in 10 to 15 minutes. Recent advances in 3D echocardiographic methods enable quantitative assessment with less variability compared to two-dimensional (2D)-based methods. However, the accuracy of 3D echo quantitation is highly dependent on the image quality. In one study, only 22% of clinical patients had the image quality required for accurate analysis.1 When compared to MRI, 3D echocardiographic methods can significantly underestimate left ventricular volumes, as much as by 67 ± 45 mL in end-diastole and 41 ± 46 mL in end-systole.2 Technical advances continue to improve the spatial and temporal resolution of 3D echo. However at the present time, resolving trabeculations by 3D echo is challenging and can lead to inaccuracies, particularly when image quality is not optimal. Additionally, most MRI labs trace the endocardial borders including the papillary muscles in the left ventricular pool, exacerbating the difference with 3D echo methods. In evaluation of patients, it is important to use the same method of quantitation and not use the different imaging methods interchangeably.

1999

Quantitative assessment of the right ventricle continues to be a challenge with echocardiographic methods. Due to the complex morphology of the right ventricle, no single view or imaging plane can provide adequate information for accurate assessment of the right ventricle. Although quantitative assessment by 3D echocardiography is better that 2D-based methods,3 it is not widely available and the technique needs further refinement before routine use. Accurate right ventricular quantitation is particularly important in arrhythmogenic right ventricular dysplasia, atrial septal defects, anomalous pulmonary veins, etc. It is standard practice to quantitatively determine RV volumetrics by cardiac MRI. The inter- and intraobserver variability by cardiac magnetic resonance (CMR) are very low4 and allows for serial monitoring of chamber volumes. Similar to the left ventricle, a short-axis stack of the right ventricle is used for analysis (Fig. 84.1).

STRAIN ASSESSMENT The complex myofiber arrangement in the heart allows it to be a highly efficient pump, such that only 10% to 15% single fiber shortening is required to generate an ejection fraction of 65% to 70%. In the midwall, the myocardial fibers generally have a circumferential layout. The myofibers become obliquely oriented in the endocardium and epicardium, but in opposite directions, resulting in a perpendicular arrangement of the endocardial and epicardial fibers. This arrangement leads to a finely orchestrated deformation sequence in circumferential, longitudinal, and radial directions. Circumferential shortening is primarily due to midwall fiber shortening. Longitudinal left ventricular shortening is the result of contraction of the

Fig. 84.1: Epicardial and endocardial contours are semiautomatically traced on a stack of short-axis slices of the left ventricle in end-diastole (shown) and end-systole. Endocardial area from each slice is measured and multiplied by the interslice distance. Thus, accurate end-diastolic and end-systolic volumes are computed and ejection fraction is calculated (EDV – ESV/EDV) and expressed as a percentage. To obtain a time volume curve of the cardiac cycle, the endocardial contours need to be traced in all phases of cardiac cycle.

2000


oblique epicardial and endocardial fibers. In general, the epicardial fiber contraction is the dominant force and the endocardial fibers shorten passively in the same direction as the epicardial fibers. Even though the greatest amount of myocardial deformation occurs in the subendocardium, this is driven by the subepicardial fibers. In the setting of ischemia, which initially affects the subendocardium, longitudinal shortening would be affected before circumferential shortening and radial thickening and therefore be a more sensitive marker.5,6 Accurate assessment of myocardial deformation has potential for clinical use; however, reliable measurements and standardization of the various echocardiographic methods has been challenging.7 MRI-based tagging was the first noninvasive technique to reliably assess myocardial strain8,9 and is considered the gold standard. Tagging involves selective destruction of magnetization in vertical, horizontal, or grid patterns along the myocardium and assessing the deformation between these tag lines (Movie clip 84.1). In general, tag lines do not persist through the entire cardiac cycle and assessment of strain in late diastole can be difficult. The most common method of tagging is spatial modulation of magnetization (SPAMM) and software packages are available for semiquantitative analysis. The technique can be time consuming and requires acquisition of

specialized sequences, making it difficult to implement in routine clinical practice. More recently, techniques such as “feature tracking” have been developed (Fig. 84.2) that can assess strain on routine cine MRI images.10 Other MRI techniques such as strain-encoded (SENC) MRI and displacement-encoded (DENSE) MRI are being evaluated, and discussion of these techniques is beyond the scope of this chapter.

LEFT VENTRICULAR STRUCTURE When compared to echocardiography, cardiac MRI provides higher definition images of the left ventricular cavity and its structure. The papillary muscles, chordal attachments, and apical anatomy are better appreciated. This has resulted in increased diagnosis of conditions like left ventricular noncompaction (LVNC).

Left Ventricular Noncompaction LVNC is an unclassified cardiomyopathy characterized by abnormal myocardium with two distinct layers: noncompacted and compacted layers. The natural history and the prognosis of this condition are not well established. Several echocardiographic criteria have been proposed to diagnose LVNC. Commonly used echocardiographic methods involve assessing the end-

Fig. 84.2: Strain imaging by CMR. The left panel depicts regional myocardial deformation by harmonic phase analysis (HARP) of tagged images. The green curve corresponds to the septum. The red curve corresponds to the lateral wall. The right panel depicts regional myocardial deformation by feature tracking analysis of steady-state free precession (SSFP) cine images. Strain analysis of seven segments in the four-chamber view is shown.


2001

Fig. 84.3: Left ventricular noncompaction (LVNC) in a young patient with recurrent episodes of syncope and history of atrial septal defect repair as a child. 2D echocardiogram showed mildly reduced left ventricular function but missed the increased trabeculation, due to suboptimal endocardial resolution. Contrast echocardiography was able to identify the abnormal myocardium, although in less detail than CT or MRI. CT angiography demonstrated normal coronary arteries and increased trabeculations. Cardiac MRI was diagnostic of LVNC. Pathological LVNC is often associated with congenital heart disease as in this patient; (CT: Computed tomography; MRI: Magnetic resonance imaging).

systolic ratio of noncompacted to compacted myocardium (ratio > 2:1 is significant), and presence of color flow in the deep intertrabecular recesses.11 The number and location of the trabeculations are taken into account in other echocardiographic criteria.12 These criteria are considered too sensitive by some,13,14 and others suggest that the echocardiographic criteria may be too strict. The sensitivity of cardiac MRI is higher than echocardiography15–17 (Fig. 84.3). The cardiac MRI criteria for LVNC use end-

diastolic ratio > 2.3:1 rather than the systolic ratio, as the myocardium is relaxed in diastole and it is easier to discern noncompacted myocardium from compacted myocardium (Figs 84.4A to C).18 MRI studies reveal that some degree of noncompaction in the left ventricular apex is very common and does not necessarily indicate pathology. Due to higher contrast resolution and better apical resolution of cardiac MRI, it is not uncommon to find apical trabeculation(Fig. 84.4C). Care should be taken

2002

A


B

C

Figs 84.4A to C: LVNC: in addition to prominent trabeculations (A), deep recesses (B) are often seen in LVNC; (C) Physiological hypertrabeculation: note the prominent apical trabeculation in C, which can be seen in healthy subjects. This does not indicate pathology.

to avoid over diagnosis. Petersen et al. found that up to 6 ± 3 myocardial segments can be noncompacted in normal subjects.19 Patients with pathological noncompaction (10 ± 3) and dilated cardiomyopathy (DCM) (7 ± 3) often have a greater number of noncompacted segments, compared to patients with hypertension, aortic stenosis, or hypertrophic cardiomyopathy (HCM).

Tissue Characterization The ability to characterize tissues by using different imaging sequences is a feature unique to MR imaging. The sequences that are most commonly used are T1 weighted, T2 weighted, fat suppression, and gadolinium-enhanced sequences. Using various MRI sequences (Table 84.1), it


2003

Table 84.1: Signal Intensity (Brightness on the Images) of Various Tissues in the Common Tissue Characterization Sequences Used in Cardiac MRI

SSFP

T1w

T2w

Fat Suppression First Pass Gadolinium (Perfusion)

Gadolinium Enhancement PSIR

Adipose







Suppressed



Fluid transudate







No Δ



Fluid exudate

Int

Int

Int

No Δ



Hemorrhagic (acute) extra cellular methemoglobin





Hemorrhagic chronic (deoxyhemoglobin, intracellular methemoglobin)







(low in sub acute)



on early and late imaging

Thrombus (chronic)









Patchy fibrosis





Multiple patchy foci in hypertrophic segments (HCM > AS)

T1 mapping techniques



Diffusely increased SI irrelative to normal myocardium

T1 mapping techniques

Thrombus acute/ subacute



Diffuse myocardial fibrosis Edema (inflammation/ ischemia)





Infarction/ necrosis





None

Patchy Midmyocardial Subepicardial Non coronary

No Δ

 Subendocardial/ Transmural Coronary distribution 

Collagen/amyloid Calcification

 



TI scout



No Δ



Iron Vascularity



Other Sequences

T2* sequence 



(AS: Aortic stenosis HCM: Hypertrophic cardiomyopathy; PSIR: Phase sensitive inversion recovery; SSFP: Steady-state free precession). Arrows indicate the signal intensity (SI) relative to myocardium. Details of the sequences are found in the text and the glossary.

is possible to reliably identify fat, fluid, thrombus, edema, infarction, and inflammation in most situations. First pass gadolinium imaging is used to assess vascularity and perfusion. Late gadolinium enhancement (LGE) is perhaps the most useful sequence for tissue characterization. The location, pattern, and intensity of LGE are helpful in assessing inflammation, fibrosis, infarction, and infiltrative patterns.

Myocardial Infarction and Viability Assessment MRI with late gadolinium imaging is the gold standard in the diagnosis and characterization of myocardial infarction. Increased interstitial space due to myocardial necrosis and fibrosis in the infarcted segment results in delayed gadolinium uptake and slow wash out compared

2004


to the healthy myocardium.18 This results in increased signal intensity of infarcted segments on late gadolinium images (10–20 min postgadolinium contrast). MRI is highly sensitive and small subendocardial infarcts (Fig. 84.5) can be easily detected on MRI due to the higher spatial and contrast resolution, even when echocardiography and SPECT imaging are normal. Histologically confirmed subendocardial infarcts were detected by LGE-MRI in 92%, whereas SPECT imaging detected only 28%.20 Infarction typically begins in the endocardium and progresses toward the epicardium. Subendocardial or transmural involvement in a coronary artery distribution is characteristic of myocardial infarction (Fig. 84.5). Microvascular obstruction (Fig. 84.6) in acute myocardial infarction (MI) is an exception, where there are areas of hypoenhancement in the subendocardium surrounded by hyperenhancement. This is due to inadequate penetration of contrast into the center of the infarction from plugging of small vessels by thrombus and debris. The transmural extent of enhancement correlates with the thickness of the nonviable scar tissue and is related to the extent of functional recovery after revascularization. In general, when there is less than 50% transmural enhancement, the myocardial segment is considered viable suggesting high likelihood of functional recovery.21 There is excellent

correlation of quantitative assessment of infarct mass by LGE with positron emission tomography (PET) infarct size.22

Fig. 84.5: Small recent subendocardial infarction in the circumflex territory (day 3). Increased signal on T2w images is consistent with edema. Edema is more extensive than the areas of necrosis seen on LGE. Echocardiography shows normal regional wall motion. (LGE; Late gadolinium enhancement).

Fig. 84.6: Anteroseptal myocardial infarction (blue arrows) on late gadolinium imaging. The red arrowheads point to a large area of microvascular obstruction.

MYOCARDITIS AND SARCOIDOSIS Cardiac MRI is considered the gold standard for the diagnosis of myocarditis (Fig. 84.7). Tissue characterization is useful in determining the presence and duration of myocardial inflammation. The location is generally in a noncoronary distribution and can be patchy or diffuse. The pattern is often mid-myocardial or subepicardial and can involve the basal lateral wall or septum. In contrast, ischemic pathology usually begins in subendocardium and progresses to the epicardium. Presence of edema and increased capillary permeability is consistent with the acute inflammatory process.23 Myocardial edema associated with inflammation can be seen as global or regional increase in signal intensity (SI) on T2w images. The sensitivity of detecting edema in acute phase of myocarditis is high (84%) with a specificity of 75%.24 Increased capillary permeability is recognized by increased contrast uptake on early gadolinium enhancement (EGE) imaging, which is quantified as at least 45% increase in signal intensity on postcontrast


2005

Fig. 84.7: Tissue characterization in acute myocarditis. Bright areas in T2w image indicate edema. Increased signal intensity in postcontrast T1 images (>45% relative to precontrast) and EGE images indicate increased capillary permeability. The area of enhancement in LGE indicates necrosis/ fibrosis (less extensive than extent of edema). (EGE: Early gadolinium enhancement; LGE: late gadolinium enhancement).

Fig. 84.8: Myopericarditis: early and late gadolinium enhancement images both show multiple foci of hyperenhancement (green arrows) in the myocardium, consistent with myocarditis. There is evidence of pericardial enhancement (blue arrows) indicating pericarditis. This appears to be limited to the basal pericardium. The pericardium in the mid-sax images does not show enhancement. A moderate sized pericardial effusion is present (star).

T1 images compared to the precontrast images. Higher signal intensity in myocardium relative to skeletal muscle, postcontrast (ratio > 4) is also indicative of increased capillary permeability. Abnormal enhancement on delayed gadolinium imaging is indicative of irreversible myocardial damage due to either necrosis or fibrosis. Delayed gadolinium enhancement occurs when there is expansion of interstitial space, due to necrosis of myocardial cells or infiltration. Small areas of necrosis seen in the acute phase of myocarditis may no longer

be seen over time due to fibrosis and scar contraction that is smaller than the threshold of the MRI sequences. Pericardial effusion and associated pericarditis can also be present (Fig. 84.8). In sarcoidosis, myocardial inflammation is characterized by noncaseating granulomas. Cardiac involvement can be seen in up to 30% of patients25 with pulmonary sarcoidosis and when present, requires aggressive treatment. The presence of multiple foci of intense hyperenhancement (Fig. 84.9) in a noncoronary distribution

2006


Fig. 84.9: Cardiac sarcoidosis: intense hyperenhancement in the basal inferolateral wall on late gadolinium enhancement images in this patient with history of pulmonary sarcoidosis and arrhythmias is suggestive of cardiac sarcoidosis.

(midwall, subepicardial, or transmural) in a patient with sarcoidosis is consistent with cardiac involvement. It is, however, difficult to differentiate sarcoid granulomas from other forms of myocarditis and definitive diagnosis requires tissue biopsy.

CARDIAC HYPERTROPHY Cardiac amyloidosis, hypertensive cardiomyopathy, HCM, storage diseases such as Fabry’s disease can all cause cardiac hypertrophy and may be indistinguishable from one another by echocardiography. Tissue characterization by MRI is useful in further evaluation of these conditions. Echocardiography is usually the reason to suspect HCM with or without obstruction. Morphological features of HCM, particularly the distribution of hypertrophy (septal, midwall, or apical) are well characterized on routine cine MRI images. Apical HCM may be missed on echocardiography due to limited apical resolution. Contrast-enhanced cardiac MRI images often, but not always, show patchy hyperenhancement in areas of

hypertrophy (Figs 84.10 and 84.11), indicating areas of fibrosis.26 Myocardial fibrosis or scarring detected by cardiac MRI occurs in up to 33% to 86% of patients with HCM. It is suggested that these abnormal areas of enhancement increase the risk for arrhythmias and sudden cardiac death.27 Whether patients with extensive areas of enhancement need prophylactic defibrillators is an area of active investigation. Abnormal myocardial deformation in the hypertrophied myocardium can be detected on tagged imaging (Movie clip 84.2). While there is no specific pattern of hyperenhancement in Fabry’s disease, midwall hyperenhancement in the basal inferolateral wall has been described in some series.28 It is uncommon to find areas of intense hyperenhancement in hypertrophy from pressure overload. A mildly increased heterogeneous signal on LGE imaging is often noted in hypertensive heart disease, aortic stenosis, etc. Pressure overload hypertrophy in these conditions generally results in diffuse myocardial fibrosis, which is difficult to detect visually. Quantitative methods such as T1 mapping are being investigated to quantitate diffuse fibrosis in these conditions.


2007

Fig. 84.10: Hypertrophic cardiomyopathy: severe hypertrophy of the septal myocardium with markedly abnormal LGE. Patchy areas of enhancement with multiple foci in the thickened septum are indicative of extensive fibrosis. (LGE: Late gadolinium enhancement).

Fig. 84.11: Apical variant of hypertrophic cardiomyopathy: focal bright enhancement (blue arrows) in the apex on contrast-enhanced image in a patient with apical HCM. Apical infarctions are also frequently observed due to coexisting microvascular disease. (HCM: Hypertrophic cardiomyopathy).

2008


Amyloid heart disease has certain unique features by cardiac MRI, allowing for a noninvasive diagnosis without biopsy. There is marked expansion of the interstitial space due to amyloid deposition resulting in hyperenhancement especially on early gadolinium imaging. The pattern is frequently diffuse subendocardial, as amyloid deposits tends to be endocardial initially, but can be more diffuse as the disease progresses (Fig. 84.12). Biventricular and atrial involvement are often present. The kinetics of gadolinium in amyloidosis is unusual due to early wash out of gadolinium from the blood pool, as a result of its binding with the amyloid protein in the blood. Anatomic features such as biatrial enlargement, thickened valves, and pericardial effusion are evident on the cine MRI images. Amyloid patients have restrictive diastolic filling, which is best detected by pulsed wave and tissue Doppler echocardiography. Echocardiography and tissue characterization by MRI are usually adequate to make a reliable diagnosis or to exclude cardiac amyloidosis in most patients.

CARDIOMYOPATHIES MRI offers additional information in the diagnosis of cardiomyopathy beyond size and systolic function. The role of MRI in dilated and other forms of cardiomyopathies is discussed below. DCM may occur in many conditions including viral myocarditis, alcoholic cardiomyopathy, hemochromatosis, thyroid disease, familial cardiomyopathy, etc. Most commonly, DCM is idiopathic and is a diagnosis of exclusion. It is believed that mechanisms specific to viral

myocarditis and chronic inflammation can eventually lead to DCM.29 Accurate chamber quantitation is useful in the initial diagnosis and monitoring of the progression of DCM. Late gadolinium images can have a variable appearance in DCM, and in general, is helpful in excluding ischemic cardiomyopathy. A frequently observed finding in DCM is a mid-myocardial “stripe” pattern30 (Figs 84.13A and B) of enhancement, which is not specific for a particular etiology. A subepicardial enhancement pattern may also be present in patients with DCM and myocarditis.31 LGE is noted in half of patients with biopsy proven myocarditis; however, an absence of LGE does not indicate absence of previous myocarditis.32 Cardiac MRI can be helpful in guiding the endomyocardial biopsy,33 by directing it toward the pathological segments. Myocarditis associated with eosinophilia can occur in a variety of conditions such as eosinophilic myocardial fibrosis, Loeffler’s syndrome, Churg-Strauss syndrome, etc. The pathophysiology involves eosinophilic infiltration of the endomyocardium, followed by necrosis and fibrosis along with thrombus formation. Any form of eosinophilic myocarditis can eventually result in fibrotic contraction and restrictive cardiomyopathy. Normal ventricular and apical contraction with characteristic subendocardial enhancement pattern and apical thrombus on late gadolinium imaging are the hallmarks of this condition34 (Fig. 84.14). While restrictive diastolic filling of the ventricles can be appreciated on cine imaging in advanced cases, diastolic abnormalities are best detected on pulsed wave and tissue Doppler echocardiography. Myocardial iron overload is an occasional cause of cardiomyopathy and can occur in conditions such as thalassemia, myelodysplasia, and hemochromatosis. Iron overload-induced cardiomyopathy is reversible if intensive chelation therapy is instituted in time. T2* imaging is a specialized gradient echo sequence that can be used to estimate myocardial and hepatic iron load.35 MRI T2* times correlate well with myocardial iron levels.

VELOCITY MAPPING, FLOW AND SHUNT ASSESSMENT

Fig. 84.12: Cardiac amyloidosis: diffuse enhancement in both the ventricles and atria (blue arrows) in a patient with cardiac amyloidosis. Also present are pericardial and pleural effusions (orange arrows).

Phase velocity imaging or velocity mapping is an MRI sequence that is used to assess velocity and flow. In this sequence, each point of the imaging plane is encoded with a phase shift, which is directly related to the velocity in that pixel. Velocity encoding can be applied in plane (in the direction of flow) or through plane to the flow (perpendicular to the flow). Through plane images are


A

2009

B

Figs 84.13A and B: “Mid myocardial stripe” pattern of enhancement on late gadolinium images is seen in this patient with dilated cardiomyopathy.

Fig. 84.14: Diffuse subendocardial enhancement (green arrows) in the left and right ventricles along with a thrombus (yellow arrow) in the left ventricular apex in a patient with Loeffler’s syndrome.

typically used for quantitative analysis. Similar to the Nyquist limit, a velocity-encoding window is specified, which determines when aliasing will occur. Generally, the velocity-encoding window is set as close as possible to the estimated peak velocity. This allows for accurate flow analysis while avoiding aliasing. Instantaneous flow volume can be calculated by measuring the velocity of all pixels in an area of interest. Integrating the flow of all phases of the cardiac cycle yields the flow volume per beat. Pulmonic (Qp) and systemic flow (Qs) can be calculated by measuring through plane flow in the proximal pulmonary artery and the ascending aorta (Fig. 84.15). Echocardiographic estimation of Qp/Qs is often prone to error due to errors in measuring the diameter of pulmonary

outflow. Error due to inaccurate estimation of area is unlikely with MRI as the through plane area is mapped and traced in each frame of the cardiac cycle. Pulmonic and systemic flow should be equal in the absence of a shunt and are generally within 10% of each other. In general, the measurement of Qp/Qs by MRI is accurate and reliable.36,37 When estimating flow, it is important that velocity mapping is performed as close to the center of the magnetic field as possible. The great vessels can almost always be positioned in the center. Any errors in flow calculation tend to cancel out when deriving a ratio; therefore, the estimation of Qp/Qs is generally very accurate. This is, however, not the case when using velocity mapping to assess valvular flow. There are several technical issues that may limit the accuracy of flow quantitation across the valves. Some of these technical issues can be addressed by paying attention to proper positioning of imaging planes, applying background correction techniques, and rigorous internal validation with flow phantoms. It is however important to realize that there are limitations of phase-velocity imaging at the present time and the data should be interpreted only by experienced users, who understand the limitations of the method. Technical improvements in velocity mapping methods are underway which will allow for reliable routine assessment flow quantitation.

VALVULAR HEART DISEASE AND PROSTHETIC VALVES Cardiac MRI allows for comprehensive assessment of valve disease, including valvular anatomy, function, flow

2010


Fig. 84.15: Forward flow through the aorta (Qs) and pulmonary artery (Qp). In velocity- mapped images, pixels with velocity in either direction are represented in grades of black or white (note the opposing colors in the ascending and descending aorta), whereas stationary objects are represented in gray. The area under the curve is integrated to obtain the flow in either direction.

quantitation, as well as provides accurate quantitative analysis of the left and right ventricles. The assessment of the ventricles is important to understand the effect of the valvular pathology on the heart and to detect progression of pathology in serial evaluation of a patient. The role of MRI in the more common valvular conditions is discussed below.

Aortic Stenosis In general, direct planimetry of stenotic valve area is the preferred method of assessing severity of aortic stenosis by MRI. Valve area can be measured in either cine images or in through plane velocity-mapped images and has been shown to correlate well with Doppler echocardiography and catheterization measures of severity.38,39 A crosssectional image through the leaflet tips in systole obtained by carefully aligning two perpendicular left ventricular outflow tract (LVOT) views is used to calculate the valve area (Fig. 84.16). Peak and mean velocities can be obtained by velocity mapping. Through planes that are perfectly perpendicular to the stenotic jet at the tips of aortic leaflets can be obtained, even in the setting of angulated aortic roots. It is also feasible to calculate aortic valve area by MRI using the continuity method similar to echocardiography. Through plane velocity maps of the LVOT and planimetered area of LVOT are obtained by obtaining a perpendicular plane through the LVOT and peak velocity obtained at the leaflet tips is used to calculate the aortic valve area.

It has to be noted that the temporal resolution of velocity mapping sequences (25–45 ms) is much lower than that of Doppler echocardiography (10-fold higher temporal resolution) and generally results in underestimation of peak velocities. In addition, magnetic field inhomogeneities and eddy currents can result in variability in measurements. For this reason, direct planimetry of aortic valve area by is preferred over the continuity method by MRI.

Aortic Regurgitation Regurgitant jets are seen as flow void on steady-state free precession (SSFP) images due to turbulence. There is a modest correlation between the width of the jet and the size of flow void with severity of regurgitation. However, severity is often underestimated when using SSFP sequences. It is often difficult to detect small amounts of aortic regurgitation and may be missed by SSFP imaging. Quantitative assessment by velocity mapping is recommended for assessment of significant aortic regurgitation. Quantitative echocardiographic assessment of aortic regurgitation (AR) can be challenging due to difficulty in visualizing the vena contracta and proximal convergence of AR jet. Assumptions involving mitral annular area calculation limit the use of the continuity equation in assessing AR. In contrast quantitative analysis by cardiac MRI, velocity mapping is relatively straightforward. Through plane flow is measured (Fig. 84.17) above the


2011

Fig. 84.16: Systolic frames of the aortic valve in long- and short-axis images are represented. The flow is in plane in long axis and through plane in short axis. Aortic valve area can be traced by planimetry in either standard cine (SSFP) images or phase image (as shown). In this example, it is easier to trace the contours on the phase image compared to the SSFP image. Respiratory artifacts and dark signal from calcification render the SSFP image technically difficult to trace. (SSFP: Steady-state free precession).

aortic valve and below the level of the coronary artery ostia, after carefully selecting the plane using two perpendicular longitudinal views of the ascending aorta. Forward and reverse flows are quantitated and regurgitant fraction is calculated as follows. Regurgitant fraction (%) = Aortic retrograde flow (mL/beat) × 100 Aortic forward flow (mL/beat). The regurgitant volume may be underestimated by velocity mapping due to the motion of the valve plane during the cardiac cycle; however, interstudy reproducibility is high and the method is useful for long-term patient follow-up.40 Quantitative assessment of left ventricular volumes and function are equally important in long-term follow-up. In the absence of other valvular regurgitation, the difference between left and right ventricular stroke volumes should equal the amount of aortic regurgitation and this can be used to quickly corroborate the velocity mapping analysis.

Fig. 84.17: Quantitation of aortic regurgitation: flow below the baseline is forward flow in systole. Flow above the baseline represents reverse flow. In this example, there is holodiastolic reverse flow consistent with significant aortic regurgitation. The calculated regurgitant fraction is 39%.

2012


Mitral Valve When assessing mitral valve with cardiac MRI, standard long-axis SSFP views are generally adequate for assessing the motion and function of mitral valve. Systematic evaluation of individual segments of mitral valve can be done to identify prolapsed segments, when there is a specific question of an anatomical abnormality (Fig. 84.18). The resolution is, however, inferior to transesophageal echocardiography, such that the anatomic detail is less well appreciated. This is generally true with cardiac MRI sequences, when assessing any thin structures that move rapidly like valve leaflets.

Mitral Regurgitation The major contribution of cardiac MRI in the setting of mitral regurgitation is quantitative assessment of regur-

gitation, ventricular volumes, and function. Quantitative analysis of mitral regurgitation is performed as follows: In the presence of single valve regurgitation: Regurgitant volume is the extra stroke volume (SV) the affected ventricle has to pump.41 Stroke volumes are calculated by quantitative analysis of the left and right ventricles at end-diastole and end-systole (SV = EDV – ESV) Mitral regurgitant volume = LVSV – RVSV (LVSV: Left ventricular stroke volume; RVSV: Right ventricular stroke volume) In the setting of mitral regurgitation, the left ventricle has to eject a higher stroke volume as it is now pumping into both the aorta and the left atrium in systole. In the setting of other coexisting valve regurgitation: Mitral regurgitant volume = LVSV – Aortic forward flow

Fig. 84.18: Multiplane cine MRI images in a patient with posterior mitral valve prolapse and anterior regurgitant jet. By prescribing multiple planes through a short-axis image of the mitral valve (last frame), it is possible to accurately localize the pathology. (MRI: Magnetic resonance imaging).


In systole, the left ventricle ejects into the aorta and the left atrium. Aortic forward flow is calculated by the velocity mapping method. Subtracting this forward volume from the left ventricular stroke volume yields the mitral regurgitant volume. This method holds true even in the setting of coexisting aortic and tricuspid regurgitation. It is also possible to directly measure the mitral inflow by through plane velocity mapping of the mitral annulus (Fig. 84.19). Subtracting the aortic forward volume from the mitral inflow volume yields the mitral regurgitant volume. However, the excessive motion of the mitral annulus during the cardiac cycle results in variable inflow quantitation and is not the preferred method of quantitation. Although not routinely performed, it is feasible to evaluate the pulmonary venous flow pattern to further assess severity of MR. As each additional sequence adds to the imaging time, this is not routinely performed.

Mitral Stenosis In general, echocardiography is the preferred method of assessing the anatomy and function of the mitral valve in mitral stenosis. By prescribing through planes perpendicular to the mitral leaflets it is possible to perform direct planimetry of the mitral valve orifice. While velocity

2013

and flow calculations are technically feasible, they are routinely not performed.

Tricuspid Regurgitation Tricuspid valve anatomy can be assessed in the standard long-axis views. Qualitative assessment of the tricuspid regurgitant (TR) jet can be difficult because of less prominent signal void in the setting of lower velocity in the right ventricle (Figs 84.20A and B). Quantitative analysis is useful and is performed using the same principles as that of mitral regurgitation. The most common method is Tricuspid regurgitant volume = RV stroke volume – Pulmonary forward flow (mL/beat). Quantitation of right ventricular volumes and function is important in the evaluation of the severity of TR and for long-term follow-up.

Prosthetic Valves Despite the prevalent misconception that prosthetic valves are a contraindication to cardiac MR imaging, almost all prosthetic valves can be safely imaged at strengths of 1.5 tesla. It should be remembered that the mechanical

Fig. 84.19: Top panel demonstrates estimation of mitral inflow at the level of the mitral annulus. The area under the curve in diastole yields the mitral inflow. Bottom panel depicts the flow pattern in the left pulmonary vein. The flow is systolic dominant.

2014


A

B

Figs 84.20A and B: Tricuspid regurgitation. The severity of valvular regurgitation is usually underestimated by SSFP sequences, particularly in the case of right ventricle, where the regurgitant jets are of lower velocity. (SSFP: Steady-state free precession).

forces of the cardiac pump have a much stronger effect on the prosthetic valve compared to the weak magnetic forces generated by MRI. Visualization of the actual prosthesis is often limited by the metallic artifact (Fig. 84.21); however, this is variable and sometimes excellent imaging is possible. Evaluation of the prosthetic valves is otherwise similar to native valves and quantitative flow using velocity mapping and volumetric analysis of the ventricle is valid in assessing prosthetic valve function.

PERICARDIAL DISEASE Echocardiography is the primary imaging modality to evaluate pericardial disease; however, MR imaging offers additional information that can help in clarification of pathology and management. Cardiac MRI methods allow for excellent tissue characterization, understanding pericardial function, as well as presence of adhesions. Normal pericardium is 1 to 2 mm thick (Figs 84.22A and B) and is generally visualized as a layer of low signal intensity on dark blood and SSFP images and is often better visualized along the right ventricle, where there is usually adipose between right ventricular free wall and the pericardium. Tagged imaging can be helpful in assessing “slippage” of the pericardium. In normal subjects, as the myocardium contracts and relaxes, it slides past the adjacent pericardium and slippage is clearly visualized (Movie clip 84.3). In the setting of adherent pericardium, the “slippage” sign is absent (Movie clip 84.4). Differentiation of pericardial effusion from epicardial fat can be difficult at times on echocardiography, particularly if the adipose is extensive and has an atypical

Fig. 84.21: Normally functioning bioprosthetic aortic valve. Artifacts from the bioprosthetic struts are noted. The bioprosthetic valve is noted to open normally in systole. Phase velocity images can be done in plane (three-chamber) and through plane (sax) to assess flow. Peak velocity can be calculated from through plane phase velocity images.

distribution. Clear distinction is possible by MR imaging owing to the different signal characteristics of fat and fluid (Fig. 84.23). Additionally, when assessing for pericardial effusion, MR imaging allows accurate determination of the size and extent of the effusion. The type of effusion can be reasonably determined by assessing the signal intensity of


A

2015

B

Figs 84.22A and B: Normal pericardium is identified by a layer of low signal between the layers of epicardial fat which has bright signal on cine and LGE images. Pericardium along the right ventricle is better visualized.

Fig. 84.23: Pericardial cyst is noted adjacent to the left ventricle (). Fluid has bright signal on SSFP images and has a higher signal on T2w (T2 > T1) images and short tau-inversion recovery (STIR) sequences. On phase sensitive inversion recovery LGE sequence, fluid appears dark. In contrast, pericardial fat (blue arrows) has bright signal on SSFP, T1 weighted, and LGE images. Additionally, signal from fat is suppressed on fat suppression and STIR sequences. (LGE: Late gadolinium enhancement; SSFP: Steady-state free precession).

2016


the effusion in various sequences. Moreover, tagged images may be helpful in assessing the fluidity and composition. For example, in the setting of free-flowing fluid, tag lines fade away quickly within the effusion (Movie clip 84.5). On the other hand, when the effusion is organized or is less fluid, the tag lines tend to persist longer. The effects of the effusion on the cardiac chambers such as chamber collapse and abnormal septal motion can be appreciated on cine images similar to echocardiography. Importantly, the presence or absence of pericardial inflammation can be determined (see Fig. 84.8) using cardiac MRI sequences. In the setting of active inflammation, there is increased signal on T2w images and hyperenhancement on gadolinium-enhanced images. The presence of any concurrent myocarditis can also be assessed. Pericardial thickening may or may not be present in pericarditis and if thickened, may have an irregular appearance. Chronic inflammation of the pericardium results in pericardial fibrosis, thickening, and occasional calcification eventually leading to constriction and impaired diastolic filling of the left ventricle (Figs 84.24A and B, Movie clip 84.6). Typical features of constrictive pericarditis such as tubular elongated appearance of the left ventricle and diastolic flattening of the septum can be easily appreciated on SSFP imaging. Paradoxical septal motion and variation with respiration can be visualized on real time imaging sequences. However, it should be kept in mind that diastolic function and respiratory variation of inflow are easier to determine with Doppler and tissue Doppler echocardiography than with cardiac MRI. Echocardiographic assessment is essential to confirm constrictive physiology and it is not advised to make a

definitive diagnosis of constrictive pericarditis based on cardiac MRI findings alone. However, the demonstration of thickened irregular pericardium and/or adhesions on tagged imaging by cardiac MRI can corroborate the clinical and echocardiographic findings to make an accurate diagnosis. It should be remembered that constriction can also occur in the absence of pericardial thickening. In this situation, cardiac MRI is of little value.

A

B

NORMAL VARIANTS AND MASSES Due to its superior spatial resolution and tissue characterization, cardiac MRI is often used to evaluate cardiac masses. A full description of cardiac tumors and their tissue characteristics is beyond the scope of this chapter. Besides tumors, normal cardiac structures can also produce “mass” like appearance on echocardiographic images. Cardiac MRI is helpful in these situations to confirm the benign nature of these “masses” avoiding further invasive procedures. Extracardiac adipose tissue is a frequent cause of a cardiac mass on echocardiography and is clearly discerned by cardiac MRI (Fig. 84.25). Epicardial fat can be difficult to differentiate from pericardial effusion by echocardiography, particularly in postoperative setting. Using tissue characterization techniques such as “fat suppression,” the true nature of the masses can be identified. Occasionally, right atrial masses seen on echocardiography are due to hypertrophic Eustachian valves and crista terminalis and their benign nature can be readily identified with MR imaging (Fig. 84.25 and 84.26). In addition to “fat suppression” sequences, which can detect the presence of adipose tissue, perfusion sequences are helpful to determine the vascularity of a mass.

Figs 84.24A and B: Pericardial thickening can be clearly seen on dark blood images along the left ventricle in this patient who had features of constrictive pericarditis (Movie clip 84.6).


2017

Fig. 84.25: This patient was referred for cardiac MRI for evaluation of multiple right atrial masses on an echocardiogram. There is extensive amount of epicardial fat that wraps around the right atrium along with lipomatous hypertrophy (blue arrows). Epicardial fat in the tricuspid annulus often appears as right atrial mass. In addition, there is a prominent eustachian valve (orange arrows). The eustachian valve is a normal atrial structure, but can be mistaken for a mass, when it is enlarged. A clue for identifying this correctly is its location at the ostium of the inferior vena cava.

Cardiac thrombi occur more commonly than tumors. Contrast cardiac MRI is particularly useful in identifying thrombus. Thrombi are characterized by lack of enhancement on first pass imaging, early, and LGE (Fig. 84.27). Intracardiac thrombi generally occur in relation to infarcted segments and atrial appendages (atrial fibrillation patients). The morphological features, location, presence of adipose tissue, vascularity, and appearance on LGE images are helpful in characterizing cardiac masses (Fig. 84.28). While there are no specific diagnostic features of malignancy, the presence of multiple lesions in multiple chambers, pericardial involvement, signal heterogeneity, areas of hemorrhage, necrosis, hemorrhagic pericardial effusion, or infiltration into other tissue layers indicate

a higher likelihood of malignancy. There is significant overlap of tissue characteristics of the various types of tumors, such that specific tissue diagnosis is not made based on cardiac MRI findings alone. Cardiac MRI is extremely helpful to evaluate the initial tumor burden and extent, as well as in the follow-up of tumors.

LIMITATIONS OF CARDIAC MRI AND CT Cardiac MRI is a powerful diagnostic tool in the cardiologist’s armamentarium. However, it is important to recognize the limitations of this modality. Patients with pacemakers and defibrillators cannot generally have an MRI. Cardiac MRI studies are usually long studies requiring patients to be supine and hold their breath. It is difficult to

2018


Fig. 84.26: The mass noted in the right atrium on the echocardiographic images was demonstrated to be hypertrophic crista-terminalis (blue arrows) and eustachian valve (orange arrows). Notice the thickened crista along the posterior wall of the right atrium that extends from the inferior to the superior vena cava. This is well characterized on the serial cine planes through the atria.

Fig. 84.27: An unusually large thrombus seen in a young female patient with diabetes, peripheral vasculopathy, nephrotic syndrome admitted with sepsis. Echocardiographic images in the upper panel demonstrate a large mass attached to the anterior wall, suspicious for thrombus. There was severe biventricular dilation and systolic dysfunction. The absence of enhancement on perfusion and late gadolinium enhancement is consistent with thrombus. Additionally, there was diffuse hyperenhancement of the myocardium and abnormal gadolinium kinetics consistent with cardiac amyloidosis.


2019

Fig. 84.28: Papillary fibroelastoma on the tricuspid valve. Note the low signal of the mass on the cine MRI (SSFP) images due to partial volume effects. There is no evidence of fat suppression or perfusion. (MRI: Magnetic resonance imaging; SSFP: Steady-state free precession).

obtain satisfactory studies in patients who are unable to lie supine, are claustrophobic, or uncooperative. While it is possible to sedate patients, the images are generally less than optimal in this situation. Most cardiac MRI images are segmented, that is, averaged over a few cardiac cycles. In the setting of arrhythmias with irregular heart rhythms (e.g. atrial fibrillation, frequent ectopy), the image quality is suboptimal. While the image contrast and tissue characterization of MR imaging is better than echocardiography, the temporal resolution is much lower (most MR sequences have 20–40 frames/s compared to echocardiography, which can image in the range of 30–100 frames/s). The slice thickness of MR images is usually 5 to 8 mm and the images have partial volume effects (Fig. 84.28). Generally, slices thinner than 5 mm do not have adequate signal and are not used. These limitations may be overcome by improvement in MR technology and development of newer sequences. Cardiac MRI is extremely helpful in many conditions; however, technical considerations may limit its value in some situations. For instance, neither SSFP nor flow sequences are sensitive or specific enough for detecting

low-velocity flow across a small patent foramen ovale (PFO) and cardiac MRI should not be used for the diagnosis of PFO. Color Doppler and agitated saline contrast echocardiography is the preferred diagnostic test. Similarly, when imaging valvular vegetations and small mobile masses by cardiac MRI, it should be kept in mind that highly mobile small masses are not well imaged due to the lower temporal resolution and partial volume effects. Transesophageal echocardiography is the preferred method. Another consideration is imaging calcific structures. In general, calcium has no signal on MR sequences due to lack of water content and is always dark on all sequences. Calcification is best imaged on X-ray or CT imaging.

CONCLUSION Cardiac MRI has become a standard diagnostic modality in today’s cardiology practice, although availability of this technique is still limited to a few major centers. It is the gold standard in the determination of cardiac volumes and evaluation of right ventricle, particularly when

2020


echocardiographic visualization is not adequate. Tissue characterization by cardiac MRI is extremely useful in the diagnosis of myocardial infarction, myocarditis, cardiomyopathies, and cardiac masses. It is important for the cardiologist and the cardiac imager to understand the unique advantages and limitations of cardiac MR imaging.

Flow Imaging (Phase Velocity/Velocity Mapping) This sequence is used to assess velocity and flow. Each point of the imaging plane is encoded with a phase shift, which is directly related to the velocity in that pixel. Velocity encoding can be applied in plane (in the direction of flow) or through plane to the flow (perpendicular to the flow). This is helpful in determining Qp/Qs and also in assessing valvular function.

GLOSSARY OF CARDIAC MRI SEQUENCES Cine Imaging Steady-State Free Precession (SSFP) This is the work horse cardiac MRI sequence. Images have a very high signal-to-noise ratio and excellent contrast between the myocardium and blood. This is a gated sequence acquired over several cardiac cycles with final display being an average of the collected data. Respiratory motion and arrhythmia can degrade the image quality.

Real Time imaging This is a nongated imaging technique used in the setting of arrhythmia or respiratory artifacts; however, image quality is inferior compared to SSFP images.

Dark Blood Imaging (Spin Echo) Spin echo sequences yield high quality images at a given time point in cardiac cycle and are generally obtained as dark blood images. These sequences are very useful for tissue characterization. T1 weighted: In this sequence, tissues with short T1 relaxation time appear bright: Example: adipose tissue (TI ~ 200 ms). Signal from tissues with long T1 (water > 2000 ms) is suppressed. T2 weighted: Tissues with long T2 have higher signal in this sequence. Example: free water has long T2 and therefore will have high signal. Fat suppression: In this sequence, signal from fat is suppressed by applying an additional excitation pulse at the frequency of fat resonance. This sequence is helpful in tissue characterization. Short-tau-inversion-recovery (STIR): This is another tissue characterization sequence with an inversion recovery prepulse that suppresses signal from fat and has higher signal from water.

T2* (Star) Imaging This is a special sequence based on signal decay, which is influenced by the tissue iron content. Tissues with high iron content have short T2*. This sequence is useful for assessing iron overload.

Contrast CMR (Gadolinium) First pass imaging (perfusion): Images are acquired in rapid succession during the first pass of intravenously injected gadolinium. This sequence can be used to assess qualitative and quantitative myocardial perfusion. First pass imaging is also useful in assessing vascularity of cardiac masses. Late gadolinium enhancement (LGE)/phase sensitive inversion recovery (PSIR): This is a T1-dependent inversion recovery sequence that highlights increased interstitial space, where gadolinium accumulates and has a delayed washout. Gadolinium decreases T1 relaxation time and when delayed images are obtained 10 to 20 minutes after gadolinium, the contrast between the healthy myocardium and abnormal myocardium (e.g. infarction, inflammation, fibrosis, infiltration) is at its maximum. The PSIR sequence further increases the contrast of the LGE sequence. Early gadolinium enhancement (EGE): EGE is performed using the same T1 inversion recovery sequence as in LGE, but performed earlier (<10 min after gadolinium). It is useful for imaging increased capillary permeability in myocarditis, amyloidosis, and thrombus imaging.

REFERENCES 1. Miller CA, Pearce K, Jordan P, et al. Comparison of real-time three-dimensional echocardiography with cardiovascular magnetic resonance for left ventricular volumetric assessment in unselected patients. Eur Heart J Cardiovasc Imaging. 2012;13(2):87–195. 2. Mor-Avi V, Jenkins C, Kühl HP, et al. Real-time 3-dimensional echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error. JACC Cardiovasc Imaging. 2008;1(4):413–23. 3. Gopal AS, Chukwu EO, Iwuchukwu CJ, et al. Normal values of right ventricular size and function by real-time 3-dimensional echocardiography: comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr. 2007;20(5):445–55. 4. Hudsmith LE, Petersen SE, Francis JM, et al. Normal human left and right ventricular and left atrial dimensions using steady state free precession magnetic resonance imaging. J Cardiovasc Magn Reson. 2005;7(5):775–82.


5. Bogaert J, Rademakers FE. Regional nonuniformity of normal adult human left ventricle. Am J Physiol Heart Circ Physiol. 2001;280(2):610–20. 6. Brecker SJ. The importance of long axis ventricular function. Heart. 2000;84(6):577–9. 7. Marwick TH. Application of 3D Echocardiography to Everyday Practice: Development of Normal Ranges Is Step 1. JACC Cardiovasc Imaging. 2012;5(12):1198–200. 8. Zerhouni EA, Parish DM, Rogers WJ, et al. Human heart: tagging with MR imaging—a method for noninvasive assessment of myocardial motion. Radiology. 1988; 169(1): 59–63. 9. Axel L, Dougherty L. MR imaging of motion with spatial modulation of magnetization. Radiology. 1989;171(3): 841–5. 10. Kadiyala M, Toole R, Reichek N, et al. Feature Tracking. A novel method to analyze myocardial strain. Results from the cardiac magnetic resonance strain study in healthy volunteers. Presented SCMR scientific sessions, Nice 2011. 11. Jenni R, Oechslin E, Schneider J, et al. Echocardiographic and pathoanatomical characteristics of isolated left ventricular non-compaction: a step towards classification as a distinct cardiomyopathy. Heart. 2001;86(6):666–71. 12. Stöllberger C, Gerecke B, Finsterer J, et al. Refinement of echocardiographic criteria for left ventricular noncompaction. Int J Cardiol. 2013;165(3):463–7 13. Kohli SK, Pantazis AA, Shah JS, et al. Diagnosis of leftventricular non-compaction in patients with left-ventricular systolic dysfunction: time for a reappraisal of diagnostic criteria? Eur Heart J. 2008;29(1):89–95. 14. Anderson RH. Ventricular non-compaction—a frequently ignored finding? Eur Heart J. 2008;29(1):10–11. 15. McCrohon JA, Richmond DR, Pennell DJ, et al. Images in cardiovascular medicine. Isolated noncompaction of the myocardium: a rarity or missed diagnosis? Circulation. 2002;106(6):e22–3. 16. Borreguero LJ, Corti R, de Soria RF, et al. Images in cardiovascular medicine. Diagnosis of isolated noncompaction of the myocardium by magnetic resonance imaging. Circulation. 2002;105(21):E177–8. 17. Pignatelli RH, McMahon CJ, Chung T, Vick GW 3rd. Role of echocardiography versus MRI for the diagnosis of congenital heart disease. Curr Opin Cardiol. 2003;18(5):357–65. 18. Petersen SE, Selvanayagam JB, Wiesmann F, et al. Left ventricular non-compaction: insights from cardiovascular magnetic resonance imaging. J Am Coll Cardiol. 2005;46 (1):101–5. 19. Kim RJ, Fieno DS, Parrish TB, et al. Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function. Circulation. 1999; 100 (19):1992–2002. 20. Wagner A, Mahrholdt H, Holly TA, et al. Contrast-enhanced MRI and routine single photon emission computed tomography (SPECT) perfusion imaging for detection of subendocardial myocardial infarcts: an imaging study. Lancet. 2003;361(9355):374–9.

2021

21. Kim RJ, Hillenbrand HB, Judd RM. Evaluation of myocardial viability by MRI. Herz. 2000;25(4):417–30. 22. Klein C, Nekolla SG, Bengel FM, et al. Assessment of myocardial viability with contrast-enhanced magnetic resonance imaging: comparison with positron emission tomography. Circulation. 2002;105(2):162–7. 23. Friedrich MG, Sechtem U, Schulz-Menger J, et al. International Consensus Group on Cardiovascular Magnetic Resonance in Myocarditis. Cardiovascular magnetic resonance in myocarditis: A JACC White Paper. J Am Coll Cardiol. 2009;53(17):1475–87. 24. Abdel-Aty H, Boyé P, Zagrosek A, et al. Diagnostic performance of cardiovascular magnetic resonance in patients with suspected acute myocarditis: comparison of different approaches. J Am Coll Cardiol. 2005;45(11): 1815–22. 25. Virmani R, Bures JC, Roberts WC. Cardiac sarcoidosis; a major cause of sudden death in young individuals. Chest. 1980;77(3):423–8. 26. Choudhury L, Mahrholdt H, Wagner A, et al. Myocardial scarring in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy. J Am Coll Cardiol. 2002;40(12):2156–64. 27. Moon JC, McKenna WJ, McCrohon JA, et al. Toward clinical risk assessment in hypertrophic cardiomyopathy with gadolinium cardiovascular magnetic resonance. J Am Coll Cardiol. 2003;41(9):1561–7. 28. Moon JC, Sachdev B, Elkington AG, et al. Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium. Eur Heart J. 2003;24(23):2151–5. 29. Liu PP, Mason JW. Advances in the understanding of myocarditis. Circulation. 2001;104(9):1076–82. 30. Mc Crohon JA et al. Differentiation of heart failure related to dilated cardiomyopathy and coronary artery disease using gadolinium-enhanced cardiovascular magnetic resonance. Circulation 2003;108:54–9. 31. De Cobelli F, Pieroni M, Esposito A, et al. Delayed gadolinium-enhanced cardiac magnetic resonance in patients with chronic myocarditis presenting with heart failure or recurrent arrhythmias. J Am Coll Cardiol. 2006; 47(8):1649–54. 32. Yilmaz A, Kindermann I, Kindermann M, et al. Comparative evaluation of left and right ventricular endomyocardial biopsy: differences in complication rate and diagnostic performance. Circulation. 2010;122(9):900–9. 33. Mahrholdt H, Goedecke C, Wagner A, et al. Cardiovascular magnetic resonance assessment of human myocarditis: a comparison to histology and molecular pathology. Circulation. 2004;109(10):1250–8. 34. Gupta D, Odie-Okon E, Kadiyala M, et al. Secondary endocardial fibroelastosis in an adult. Tex Heart Inst J. 2012;39(5):761–3.

2022


35. Anderson LJ, et al. Magnetic resonance for the early diagnosis of myocardial iron overload. Eur Heart J. 2001; 22:2140–1. 36. Firmin DN, Nayler GL, Klipstein RH, Underwood SR, Rees RS, Longmore DB. In vivo validation of MR velocity imaging. J Comput Assist Tomogr. 1987;11(5):751–6. 37. Meier D, Maier S, Bösiger P. Quantitative flow measurements on phantoms and on blood vessels with MR. Magn Reson Med. 1988;8(1):25–34. 38. Søndergaard L, Hildebrandt P, Lindvig K, et al. Valve area and cardiac output in aortic stenosis: quantification by magnetic resonance velocity mapping. Am Heart J. 1993;126(5):1156–64.

39. Friedrich MG, Schulz-Menger J, Poetsch T, Pilz B, Uhlich F, Dietz R. Quantification of valvular aortic stenosis by magnetic resonance imaging. Am Heart J. 2002;144(2): 329–34. 40. Dulce MC, Mostbeck GH, O’Sullivan M, Cheitlin M, Caputo GR, Higgins CB. Severity of aortic regurgitation: interstudy reproducibility of measurements with velocity-encoded cine MR imaging. Radiology. 1992;185(1): 235–40. 41. Hundley WG, Li HF, Willard JE, et al. Magnetic resonance imaging assessment of the severity of mitral regurgitation. Comparison with invasive techniques. Circulation. 1995; 92(5):1151–8.

CHAPTER 85 Cardiac CT Imaging Satinder P Singh, Sushilkumar K Sonavane

Snapshot  Challenges for Cardiac Computed Tomography  RadiaƟon Dose  PaƟent SelecƟon  Technique  Image Postprocessing  Image Analysis  Piƞalls and ArƟfacts  DiagnosƟc Accuracy of Coronary Computed

 Coronary Plaque  PrognosƟc InformaƟon from Coronary Computed

Tomography Angiogram  Cardiac FuncƟon  Myocardial Perfusion  How to Improve Accuracy of Computed Tomography

Angiogram in Determining Flow LimiƟng Disease  Clinical IndicaƟons

Tomography Angiogram

INTRODUCTION In the 1980s, the electron beam computed tomography (EBCT) was introduced and was able to freeze cardiac motion with a temporal resolution (TR) of 50 ms. EBCT was used extensively for early coronary artery calcium (CAC) evaluation. However, its role for CT angiography was limited due to excessive noise and poor spatial resolution (SR) from 3 mm to 4 mm thick images. Multidetector computed tomography (MDCT), which was introduced in the late 1990s, has rapidly evolved over the past few years. A 64-MDCT is capable of providing TR of 165 ms (85 ms with dual source scanner), SR of 0.4, slice thickness of 0.6, and gantry rotation time of 330 ms or even less (Table 85.1). MDCT can provide information about coronary artery patency, coronary calcium, left ventricular (LV) function, and to some extent even myocardial perfusion. In addition, extracardiac sources of chest pain

such as esophagitis, pneumonia, pulmonary embolism, aortic dissection, as well as chest wall abnormalities can also be evaluated in the same setting. In the last 4–5 years, we have also seen dramatic improvement in postprocessing and segmentation capabilities due to the availability of powerful computers and their supercomputing powers. Coronary artery disease (CAD) is a leading cause of mortality and morbidity in industrialized nations. The management decisions often depend upon accurate evaluation of coronary artery lumen. Catheter coronary angiography is considered the gold standard for coronary arterial evaluation due to its superior temporal and SR. Although not insignificant, there is a complication rate of about 3.6% and a mortality of 0.1% associated with this procedure.1 It gives accurate luminal information but lacks information about vessel wall and presence and type of plaque. Coronary computed tomography (CCT) angiography not only provides anatomical information

2024


Table 85.1: Comparison of Spatial Resolution (SR) and Temporal Resolution (TR) for Different Modalities

Modality

Spatial Resolution (SR) [mm]

Electron beam computed tomography (EBCT)

Temporal Resolution (TR) [ms]

> 0.6

50–100

16-Multidetector computed tomography (MDCT)

0.5

250–400

64-MDCT

0.4

165–250

Dual Source

0.4

83

Catheter Angio

0.2

5–20

Cardiac magnetic resonance imaging (CMRI)

0.7

20

regarding the coronary artery lumen and presence of stenosis but also information regarding the vessel wall and remodeling not seen on conventional catheter angiography. Due to its near-isotropic image resolution, cardiac CT is well suited to evaluate complex congenital heart diseases (CHDs). It provides information about cardiac chambers, valves, pulmonary and coronary veins, and any extracardiac pathology in the mediastinum/hilum or visualized lungs. Advantages of cardiac CT include its noninvasive nature, excellent SR, good TR, excellent patient acceptance, wide availability, simple and fast technique, and no contraindication to existing hardware.

CHALLENGES FOR CARDIAC COMPUTED TOMOGRAPHY Small size of coronary arteries, complex cardiac anatomy, and cardiac motion are the three main challenges for CT evaluation of heart and coronary arteries. Several factors defining CT performance include: (a) Volume coverage per second, defined by detector coverage, pitch, and gantry rotation time; (b) SR defined by detector size in longitudinal direction, scan field of view (FOV) and image matrix in axial plane, and slice reconstruction increment; (c) TR defined by gantry rotation time and reconstruction method.

Spatial Resolution It refers to the ability to resolve as separate forms, small objects that are very close together. Submillimeter SR with isotropic imaging (i.e. equal resolution in all three planes) is desirable to delineate small coronary artery branches. The SR in CT depends on the size of the three-dimensional pixels (voxel) in the image as seen on the monitor. The smaller the size of voxel the less partial volume averaging and better SR. The voxel size depends on the resolution of the X-ray sensors and the focal spot size. It may also depend

on the type of material used in the detectors. The SR of CT is excellent at around 0.4–0.5 mm and is the primary strength of CT (Table 85.1). For most practical purposes, this resolution currently is good enough to evaluate larger epicardial coronary arteries and their branches. However, to optimally evaluate calcified smaller coronary artery branches or patency of coronary artery stents, a SR of 0.2 mm or less is required. Higher SR also increases image noise and to maintain sufficient signal to noice ratio (SNR), radiation exposure needs to be increased. Flat panel volume CT scanners have much higher SR but their contrast and TR are much inferior to current MDCT.

Temporal Resolution TR of a CT scanner is determined by the speed of rotation of the gantry. Since images may be reconstructed from a 180° rotation rather 360° rotation, the TR is equal to half the gantry rotation speed. The current generation of scanners has a very fast gantry rotation time of 0.27–0.30 ms. Excessive mechanical forces and G forces are the limiting factors in further increasing the gantry rotation. Two possible ways to improve TR are multisegment reconstruction and use of dual source CT scanner. Multisegment reconstruction selects small portions of projection data from various heart cycles and combines all projections to obtain sufficient data for image reconstruction (TRmax = TR/2 × M). However, variable heart rhythm can cause image degradation due to misregistration. Dual source CT design uses two X-ray tubes and two detectors mounted on the gantry with a 90° angular offset and leads to high TR of 83 ms (one-fourth rotation time; Table 85.1).

Cardiac Gating Electrocardiography (ECG) gating of the tomographic images is commonly performed in cardiac CT. Gating not only minimizes cardiac motion artifacts and allows

Chapter 85: Cardiac CT Imaging

2025

localization of an image to a particular phase of cardiac cycle but also improves visualization of smaller structures (Figs 85.1A and B). Both prospective and retrospective electrocardiography (ECG) gating are available. In prospective gating, imaging is done in axial scan mode at a predetermined interval from the preceding R-wave, and usually image acquisition occurs in late diastole when the cardiac motion is minimal. Images are obtained every other heart beat with table moves in between; therefore, such an acquisition is also known as step and shoot mode. Since radiation exposure occurs only for a short period in diastole, this reduces the radiation exposure to the patient. Prospective gating can only be done in patients with low and regular heart rates, and since no systolic information is gathered, cardiac functional analysis cannot be performed. In retrospective gating, imaging is done in helical mode and continues throughout the cardiac cycle. Therefore, the radiation exposure to the patient is significantly higher. Since both diastolic and systolic data are captured, functional analysis of the CT data can be performed to determine ejection fraction (EF), stroke volume, and ventricular volumes. The accuracy of left and right ventricular function by MDCT has been validated with echocardiography and magnetic resonance (MR).2–4 In addition, qualitative assessment of regional LV function is performed by visualizing changes in wall thickness using a cine loop display of multiple cardiac phases (10–90%). Regional wall-motion abnormalities are also shown to correlate with MR and echocardiography.5–8

X-Rays have been classified as carcinogens by WHO and CDC. Per-capita radiation dose from clinical imaging exams in the United States increased almost 600% from 1980 to 2006. Globally, 93 million CTs per year are done at 16/1,000 persons rate, which includes 58 million CTs yearly in the United States and 3 million CTs performed annually in children < 15 years. CT scans deliver almost half of the estimated collective radiation dose in the United States.9,10 In an article published in the New England Journal of Medicine, the authors Brenner and Hall predicted that in a few decades, 1.5–2% of all cancers in the United States may be due to the radiation exposure from CT scans being done now.11 They used dose-response information from the atomic bomb survivors to calculate the risk for patients undergoing CT procedures. This claim has been disputed by American College of Radiology (ACR) using the following arguments: (a) CT exams result in limited radiation exposure to the body parts, whereas the atomic bomb survivors experienced instantaneous radiation exposure to the whole body; (b) CT exams expose patients solely to X-rays, while atomic blast survivors were exposed to X-rays, particulate radiations, neutrons, and other radioactive nuclei. Therefore, the known biological effects are very different for these two scenarios. Nonetheless, ACR supports the “as low as reasonably achievable” (ALARA) concept and urges providers to use the minimum level of radiation needed in such exams to achieve the

A

B

RADIATION DOSE

Figs 85.1A and B: (A) Nongated versus (B) Gated axial computed tomography (CT) image. Gated image showed minimal cardiac motion related artifact, which helps in visualization of small size structures such as coronary arteries. (AO: Aorta; LAA: Left atrial appendage; PA: Pulmonary artery).

2026


necessary results. The typical radiation dose exposure from commonly performed procedures is show in Table 85.2. Two radiation parameters are available from the CT study—the CT dose index volume (CTDIvol) and the dose length product (DLP). The DLP is obtained by CTDIvol multiplied by the total scan length. Effective dose, measured in milliSieverts (mSv), is calculated by the DLP multiplied by tissue weighing factor (k) that takes into account the relative sensitivity of a particular body region. For cardiac imaging, the most commonly used k-factor is 0.014. It reflects the relative risk from exposure to ionizing radiation and accounts for the characteristics of exposed tissues. The effective radiation dose in mSv allows us to compare different forms of radiation such as X-rays and isotope exposures in nuclear medicine studies (Table 85.3).

Methods to Reduce Radiation Exposure (Table 85.4) •

Individualized protocols: The technique of computed tomography coronary angiography (CTCA) is particularly amenable to “dose optimization” by tailoring the scan protocol to the individual patient. Adjustments are made to the tube current (mAs) and tube voltage (kVp) according to patient size and anatomical shape. The range of mAs (400–800) and kVp (80–120) are utilized in our practice. – The CT radiation dose changes in proportion of square of the tube voltage. Thus, small changes in tube voltage have more impact on the radiation dose. In the PROTECTION I study, the use of the 100-kV tube voltage protocol was associated with 53% reduction in radiation dose, when compared

Table 85.2: Typical Effective Doses of Common Examinations

Modality

Effective Radiation Dose (mSv)

Chest radiograph (CxR) PA/Lateral

0.02–0.04

Mammogram

0.4

Head computed tomography (CT)

1–3

Chest computed tomography angiogram (CTA) for (pulmonary thromboembolism (PTE)

8–10

Abdomen CT routine

10–12

Multiphase abdomen/pelvis CT

22–34

Catheter Angio

3–7

SPECT

(7–9) Rest or Stress only (18–23) Rest and Stress

Coronary CTA

6–13 (retrospective) 1–5 (prospective), < 1 (High Pitch)

Thallium 201

21–23

Trans Atlantic Flight

3.0

Average US background

3.6–4.5

Table 85.3: Computed Tomography Radiation Dose Descriptors

Volume computed tomography (CT) dose index

CT dose index volume (CTDIvol) [mGy] Average dose within the scan volume (CTDI/Slice)

Dose length product

Dose length product (DLP) [mGy.cm] Integrates CTDI vol over the scan length (DLP/Scan) Reflect biological effects attributable to a complete scan acquisition

Effective dose

E (mSv)


Table 85.4: Methods to Reduce Radiation Dose in Cardiac Computed Tomography

Choose correct protocol for a given question kVp: 80, 100, 120, 140 mA: Lower the better Dose modulation Iterative reconstruction (ASIR, iDose, SAPHIRE, VEO) High pitch computed tomography angiogram (CTA; only applicable with dual source scanners)

•

•

•

with the conventional 120-kV scan protocol.12 It is important to reduce both tube current and more so the tube voltage whenever possible while maintaining the image quality. At our institution we try to apply 100 kVp to patients with body mass index (BMI) < 26. FOV: Since the radiation dose is directly proportional to the scan length, restriction of FOV in Z-axis to the heart, just above origin of coronary arteries to just below the inferior wall of the left ventricle is of vital importance. Preceding calcium scan if done can be used as a reference to optimize FOV for computed tomography angiogram (CTA). In cases where there are no calcium scans done, we start just below the carina. This limits excessive exposure and further application of proper filters limit X-ray scatter toward detectors. Hausleiter demonstrated that a 1% increase in scan length was associated with 5% increase in radiation.13 Prospective versus retrospective gating: The current trend is more in favor of using prospective gating due to tremendous radiation dose savings. PROTECTION I, a large international multicenter study in 2009 involving more than 50 sites reported a mean effective dose of 12 mSv where only 6% of studies were prospectively gated.13 Whereas a study by Freeman et al. showed a mean effective radiation dose of 3.39 mSv using prospective gating.14 High pitch protocols: Several recent studies done on a dual source scanner using a high pitch of 3.4 (compared to standard 0.2 in conventional scanners) have reported coronary computed tomography angiogram (CCTA) acquisition with extermely low radiation dose of around 1 mSv.15–19 This technique is only applicable for dual source scanners and requires a low heart rate of < 60 bpm to avoid motion artifacts.

2027

PATIENT SELECTION The revised 2010 appropriate use criteria for cardiac CT were published in 2010.20 Use of noncontrast CCT for calcium scoring is rated as appropriate in intermediate and selected low-risk patients. CCTA is considered appropriate in: (a) Patients with suspected anomalous coronary artery, symptomatic patients with low to intermediate pretest probability for CAD who have normal ECG and cardiac biomarkers, uninterpretable or nondiagnostic ECG or equivocal biomarkers; (b) New onset heart failure with reduced left ventricular ejection fraction (LVEF) in low to intermediate probability for CAD and preoperative coronary assessment prior to noncoronary cardiac surgery and intermediate pretest probability; (c) Patients with prior equivocal stress testing or when there is discordance between the stress test and clinical suspicion for CAD; (d) Evaluation for bypass patency after coronary artery bypass graft (CABG) and prior left main (LM) coronary stenting in asymptomatic patients; (e) Cardiac structure and function category, with appropriate indications including coronary anomalies, CHD, evaluation of right ventricle (RV) function, evaluation of LV function when imaging from other modalities is inadequate or evaluation of prosthetic heart valves; (f ) Preablation pulmonary valve (PV) mapping or prior to redo sternotomy in reoperative cardiac surgery.

Contraindication for Computed Tomography Angiogram Some of the contraindications for CCTA include: (a) renal insufficiency; (b) IV contrast allergy; (c) inability to hold breath or follow verbal commands; (d) persistently elevated heart rate, frequent premature ventricular contractions (PVCs) or premature atrial contractions (PACs). Presence of atrial fibrillation (AF) is a relative contraindication depending on the ventricular rate (VR).

TECHNIQUE Important steps to prepare patients for cardiac CT/ CTE are listed in Table 85.5. A radiologist or cardiologist should monitor and supervise all CCTA studies for optimization of protocol and best results. The type of gating and technical parameters should be chosen based on the clinical question asked, patient BMI, and heart rate (Tables 85.6 to 85.11).

2028


Table 85.5: Patient Prep for Computed Tomography Angiogram

Labs and screening

For any C/I (renal failure, contrast allergy), note any pacemakers, details of bypass surgery

Oral -blockade

3 days preferred

Patient education and instructions

Explain what to expect No solid food × 4 hours No coffee or stimulants Arrive at least 30–60 minutes before exam

IV access

Prefer anticubital fossa, at least 20 ga, test flush with saline

Electrocardiography (ECG) electrodes Proper placement Heart rate

If > 70 bpm, give oral or iv -blocker; ideal close to 60 bpm

Practice breath hold

When patient is on the table

Table 85.6: Coronary Calcium Score Protocol

Scanning Mode

Axial

kV

120

mAs

140–240

Rotation time

0.5

Collimation

Table 85.7: Coronary Computed Tomography Angiogram Protocol on 64 Detector Scanner

Scanning Mode

Helical

kV

80–120

mAs

>600

Rotation time

0.4

64 × .65

Collimation

64 × .625

Pitch

0.2

Pitch

0.2

Field of view (FOV)

220

Field of view (FOV)

220

Filter

CB (standard cardiac)

Filter

CB (standard cardiac), sharper (stent)

Slice thickness

2.5 mm

Slice thickness

0.67 mm

Increment

2.5 mm

Increment

0.33 mm

Acquisition

Helical

Acquisition

Axial

IV contrast

yes, 80–100 cc, 4–5 cc/s

Gating

Prospective

Saline chaser

40 cc at 4–5 cc/s

IV contrast

none

Gating

Retrospective

Effective Dose

1–3 mSv

Effective Dose

10–15 mSv

Table 85.8: Preablation Pulmonary Valve Mapping (Prospective Gating)

Slice Thickness

1.4 mm

Increment

0.7 mm

Region of interest (ROI)

Left atrium

Contrast

40–80 cc at 4 cc/s*

*Depends on body mass index (BMI) and if patient is getting ablation the same day.

necessitate evaluation of CCTA on a workstation capable of two- and three-dimensional (2D and 3D) display. The interpreting physician must know how to do the postprocessing and not just rely on processed images by the technologist. The common reformation methods used are: multiplanar reformation (MPR), maximum-intensity projection (MIP), shaded surface display (SSD), and direct volume rendering (DVR).

Transaxial Images IMAGE POSTPROCESSING Complexity of coronary anatomy, cardiac motion, calciumrelated artifacts, and the subtle nature of coronary lesions

Series of 2D images stacked in the longitudinal (Z-axis) direction in which they are acquired provide minimum distortion or errors and maximum resolution and gray-scale rendering. Since tortuous vessels will move


2029

Table 85.9: Transcatheter Aortic Valve Replacement (Retrospective Gated Chest and Nongated Abdominal/Pelvis Using Same Contrast Bolus)

Contrast

60–100 cc at 3–3.8 cc/s [depending on renal function and body mass index (BMI)]

Saline chaser

70 cc at same rate as contrast

Bolus technique

With threshold set for 100 H.U. in the ascending aorta

Table 85.10: Contrast Media and Injection

Concentration

300, 320, 370

Flow rate 4–7 cc/s

Weight/ body mass index (BMI) based verus fixed rate

Phases

Two phase (contrast + saline) Three phase (contrast + contrast/saline + saline)

Bolus technique

Based on predetermined threshold (usually 150 H.U.) ROI in ascending or descending aorta

Time bolus

Inject a 15- to 20-cc test bolus and calculate time to peak

Table 85.11: Optimization of Cardiac Computed Tomography Angiogram

Before

Decrease heart rate (most crucial)

During

Tailor exam according to indication Breath hold Do not use dose modulation if large patient or variable heart rate Optimum contrast opacification

After

Electrocardiography (ECG) editing Use optimal W/L Proper phase selection and postprocessing method

in and out of plane as the slice thickness is not variable, it requires the reader to mentally reconstruct the 3D anatomical relationships of the vessels and other structures (Movie clip 85.1).

Multiplanar Reconstruction A plane is defined inside the 3D volume, and only data in this plane is displayed. It is performed by using either straight or curved planes; thickness is set to zero as a default to optimize image quality, but can be changed (slab MPR). Its advantages include ease of use and speed, provision of images containing all available information (all Hounsfield unit values retained), usefulness in delineating the morphology of the plaque, and its effect on the lumen and adjacent vessel wall. Several disadvantages include its operator dependence, prone to introduce false-

positive and -negative stenosis, viewing from multiple different view points is required (double oblique method), and only one branch of a vessel is displayed at a given time (Figs 85.2A and B).

Curved Multiplanar Reformation This allows to follow the course of a tortuous vessel for longer distances as it changes direction. It requires the centerline to be tracked correctly (done manually or automatically) and, therefore, allows visualization of the entire course of the vessel in one image (Fig. 85.3). However, inaccurate centerline tracking may lead to pseudo lesions (Figs 85.4A and B)

Maximum-Intensity Projection This involves projection of highest-attenuation voxels within volumetric data (all points below this value are ignored). It uses thicker sections to include vessel lumen and its wall (usually 4–5 mm for coronary), optimizes visualization and tracking of contrasted structures and is especially useful for blood vessel depiction (Fig. 85.5). The advantages include: visualization of a longer segment of a vessel’s course, reducing perceived image noise, good differentiation between vessels and background, and finally is useful when metal is present because of decreased artifacts with this rendering. Loss of lesion information within the slab volume (as MIP does not provide in-depth information) and interference from overlapping structures are its main limitations.

2030


A

B

Figs 85.2A and B: Double oblique method. A 54-year-old male with chest pain and abnormal stress MPT: Mixed plaque is seen in the proximal left anterior descending (LAD) and more noncalcified plaque in mid-LAD after the origin of D1 (red arrow). Using the double oblique method, the area of narrowing can be validated in three different planes.

Volume Rendering This used to be a very tedious and time-consuming process, but now with advanced fast computing powers of modern processors this process is done with one or few clicks. Due to its capacity to display multiple tissues and their relationships to one another, VR is useful for visualizing spatial relationships such as defining the course of coronary anomalies, presence and course of the bypass grafts as well as in the analysis of thoracic CV structures and complex CHD (Figs 85.6A and B). VR images are impressive and often used for teaching and

illustrations for patients (Movie clip 85.2). VR images still are somewhat operator-dependent and should not be used for assessing vessel narrowing, which can be misleading (Movie clip 85.3).

Virtual Endoscopy In this technique, the dense contrast within the vessel is made transparent while the wall of the vessel is opaque, viewed from the point of view of an observer positioned within the vessel. It creates dramatic images but its clinical utility is limited at this time.


2031

Fig. 85.3: Curved multiplanar reformation (MPR). Centerline tracking allows visualization of the entire opacified vessel in one image. Most current vendors provide semiautomatic centerline placement with one or two points of seeding.

A

B

Figs 85.4A and B: The centerline point shown in green is outside the vessel in image (A) causing an area of false stenosis on the curved multiplanar reformation (MPR). After correctly placing the seed in the lumen of the coronary artery, the pseudostenosis disappears.

2032


Fig. 85.5: Maximum-intensity projection (MIP) images optimize visualization and tracking of contrasted structures such as coronary arteries and aorta. (AO: Aorta).

A

B

Figs 85.6A and B: (A) Normal coronary artery. The frontal view demonstrates the most anterior chamber as the right ventricle and right coronary artery coursing in the right artrioventricular (AV) groove (arrow). The broad pyramidal-shaped right atrial appendage (RAA) is nicely seen. The aorta (AO) is to the right of the pulmonary artery (PA), which is more anterior and to the left of the aorta. (AO: Aorta; PA: Pulmonary artery; RA: Right atrium; RV: Right ventricle); (B) The axial volume rendered image shows the anomalous origin of the right coronary artery from the left cusp (red arrow) with interarterial course (yellow arrow). (L: Left cusp; LA: Left atrium; NC: Noncoronary; PA: Pulmonary artery; R: Right cusp).

IMAGE ANALYSIS Coronary artery evaluation should be done using the standard AHA 17-segment evaluation. The coronary arteries originate from superior portions of the sinuses just below the sinotubular junction (Fig. 85.7). The normal coronary artery origin is often situated at a right angle to the aortic root wall, whereas anomalous coronary artery origins are often at acute angles. The left coronary artery originates from the left sinus of Valsalva and courses between the right ventricular outflow tract (RVOT) and the left atrial appendage (LAA). It typically divides into

two major branches, the left anterior descending (LAD) and the left circumflex (Cx) artery (Fig. 85.8). Sometimes there is an additional third branch known as ramus intermedius, which courses between the diagonals and the obtuse marginal (OM) branches and supply a territory of the LV that might otherwise be supplied by a diagonal or OM branch. When the ramus branch is a large branch, the corresponding diagonal or OM branches are often small in size. LAD courses in the epicardial space along the anterior interventricular groove between the right and left ventricles and supplies blood flow to the interventricular septum via perforators and to the


2033

Fig. 85.7: Normal coronary artery origin volume rendering (VR). Normal coronary arteries originate from coronary sinuses just below the sinotubular junction at near-right angle. (L: Left cusp; R: Right cusp).

Fig. 85.8: Volume rendered computed tomography (CT) image of aortic root and coronary arteries in left anterior oblique (LAO) projection view show the RCA, (LM: Left anterior descending (LAD), and Cx arteries with their major branches. (AO: Aorta; LV: Left ventricle).

anterior and anterolateral walls of the LV through diagonal branches. The branching pattern of LAD is quite variable. The left circumflex (LCx) courses in the left atrioventricular groove between the left atrium (LA) and LV, and provides flow to the lateral and posterior lateral walls of the LV through OM branches. The right coronary artery (RCA) arises from the right sinus and courses within the right atrioventricular groove between the right atrium (RA) and RV. It supplies acute marginal branches to the free RV wall. The conus artery typically arises as a first branch from the proximal RCA and courses around the RVOT and terminates on the anterior aspect of the heart. In 50–60% of patients, the sinonodal artery arises from the RCA and courses posteriorly between the aortic root and RA toward the cavoatrial junction. The RCA continues to the crux of the heart and gives rise to the posterior descending artery (PDA), which supplies the posterior aspect of the interventricular septum. RCA then continues to supply the posterior LV via Posterolateral (PL) LV branches. Coronary dominance refers to the supply of the PDA and PL LV branches. The most common coronary system is right dominance (> 85%) where both PDA and PL LV branches are supplied by RCA (Fig. 85.9A). In a left dominant system (8–10%), the LCx supplies the posterior LV branches (Fig. 85.9B). In a codominant or balanced system (5–10%), the RCA supplies the PDA and LCx supplies the PL LV branches (Fig. 85.9C). Myocardial bridging is a congenital variation where a segment of the epicardial coronary artery is tunneled through the myocardium (Fig. 85.10).

This is most commonly seen in the LAD and is more often visualized on CTA studies in comparison to catheter angiograms. The clinical significance of this variation is not clear but according to some it may have a protective effect on the tunneled portion.21 Coronary artery stenosis should be described in detail and should include its location, degree, number, quantification, factors affecting evaluation, any positive (Figs 85.11A and B) or negative (Figs 85.12A and B) remodeling, and features of plaque including its size, density, and presence of ulceration.

Proper Phase Selection In retrospective gated studies, it is important to always scroll through all phases to select the best phase with the least motion. All coronary vessels are usually best seen in diastolic phase image (60–80% of R–R interval), whereas RCA sometimes is better seen in the systolic phase especially in patients with higher heart rates (Figs 85.13 and 85.14).

Extracardiac Findings It is important for the imager to look at the entire FOV for any given patient. In our experience we have found unexpected lung nodules, lymph nodes, pulmonary embolism, pneumonia, esophagitis, and aortic dissection (Figs 85.15 to 85.18). In a study of 6,920 patients who underwent diagnostic CCTA, the authors found presence of extracardiac findings in almost one fourth of all patients.

2034


A

B

C

Figs 85.9A to C: Coronary dominance (A) Right dominance. Right dominance, seen in the majority of the population is shown in the axial maximum-intensity projection (MIP) image. Both posterior descending artery (PDA) and PL LV branches are arising from RCA; (B) Leftsided dominance. Left-sided dominant circulation, where the PDA and PL LV branches arise from the left circulation; (C) Codominance pattern of coronary circulation. Inferior volume–rendered view of the heart shows the codominance pattern of coronary circulation. The PDA (yellow arrow) is supplied by the RCA while the PL LV (white arrow) territory is supplied by the Cx. The codominance pattern is the second most common circulation pattern after the most common right circulation pattern.

In their study, several serious diagnosis were missed when reviewing only the limited FOV images and use of broad FOV led to more workup and follow-up.22

PITFALLS AND ARTIFACTS Cardiac Motion Artifact Lower and steady heart rate is very critical for obtaining a good quality CTA. Even with the newer 256, 320 detector as well as dual source scanners, the emerging consensus is to have heart rate as low as possible preferably close to 60 bpm to optimize image quality. The RCA shows maximum motion during the cardiac cycle followed by LAD and Cx (Movie clips 85.4A and B). The TR of current Fig. 85.10: Myocardial bridge. The proximal left anterior descend- scanners is getting better but is not closer to 50 ms required ing (LAD) courses through the myocardium (red arrow) for a short to achieve motion-free coronary artery imaging. Misalidistance and then follows the normal epicardial course. gnment or slab artifact results from a high heart rate,


A

2035

B

Figs 85.11A and B: Coronary computed tomography angiogram (CCTA) 4 mm thick axial maximum-intensity projection (MIP) image shows tight narrowing in the mid-left anterior descending (LAD; red circle), which was confirmed at catheter angiography. The outer wall to outer wall size of the vessel at the site of noncalcified plaque is larger as compared to vessel proximal to stenosis suggesting positive remodeling, which is one of the features of vulnerable plaque.

A

B

Figs 85.12A and B: In this young 47-year-old male with acute chest pain, the coronary computed tomography angiogram (CCTA) demonstrates significant stenosis of the mid-left anterior descending (LAD) near the origin of the septal branch. The outer to outer size of the vessel in this region is actually decreased in comparison to the proximal vessel suggesting the presence of negative remodeling. Catheter angiogram confirmed the presence of fibrotic narrowing in the LAD.

2036


A

B

Figs 85.13A and B: Proper phase selection. In studies done using retrospective gating, the entire cardiac cycle images are available from 0% to 90% RR intervals and can be reconstructed at 5–10% increment. Since cardiac motion is minimal in the mid to late diastole, the left coronary circulation is best visualized during the diastolic phase as shown in these images. The right coronary artery is also seen best in diastole except in a few instances where it is actually better seen at end-systole.

A

B

C

Figs 85.14A to C: Proper phase selection. RCA in 30%, 40%, and 80% phase. The last image also shows misregistration artifact (arrow).

irregular heart rate, or presence of arrhythmia and is often best seen on coronal or sagittal reconstructed images (Figs 85.19A and B).

preferably exercised to hold her/his breath before image acquisition. Unlike ECG editing, which can improve image quality in patients with mild arrhythmia, one cannot do much with respiratory motion artifacts (Figs 85.20A and B).

Respiration Motion Artifact With the current scanners, very short 4–10 seconds breath hold is required and is easily tolerated by majority of patients. The patient still needs to be instructed and

Blooming Artifacts These occur with high attenuating structures such as coronary stents or calcification due to partial volume


A

2037

B

Figs 85.15A and B: Extracardiac findings. In limited field of view (FOV) computed tomography angiogram (CTA), the right hilar and subcarinal nodes (arrows) are barely visible at the edge, but become obvious with wide FOV image (B).

A

B

Figs 85.16A and B: The right lower lobe pulmonary embolisms (arrow) seen in wide field of view (FOV) image (B) can be missed altogether if only limited FOV images (A) are reviewed.

A

B

Figs 85.17A and B: The nodule in the left upper lobe is difficult to appreciate in image (A) and can mimic an end on vessel. It is easy to find on the wide field of view (FOV) image (B). The nodule in this patient was proven to be metastasis from renal cell carcinoma.

2038


A

B

Figs 85.18A and B: Extracardiac findings. A 45-year-old female presented with severe chest pain. A gated cardiac computed tomography (CT) was performed and showed normal coronary arteries but there was severe thickening of the entire thoracic esophagus (arrows), which is better appreciated in wide field of view (FOV) image (B).

A

B

Figs 85.19A and B: Misregistration artifact due to variability in heart rate is better appreciated on coronal image (B, arrow) than the axial image (A).

averaging and cause excessive blooming and overestimation of coronary luminal narrowing (Figs 85.21A to C). A dual energy technique can provide images without calcifications and may prove to be useful in better assessment of coronary luminal narrowing by enhancing vessel visualization. Similarly, monochromatic imaging at different keV has been shown to decrease blooming from calcium at 140 keV in comparison to lower keV.23 Coronary stent-related artifacts can be improved by using a sharper kernel for reconstruction as well as with thinner images, although at the cost of slightly increased image noise (Figs 85.22A and B).

Beam-Hardening Artifacts An X-ray beam passing through a high-density structure gets attenuated with most of its low energy photons absorbed. In locations near such high attenuating material, the X-ray beam maintains its low as well as high energy photons, resulting in an area of low density in the image. A common location for such an artifact is LV apex and posterolateral wall of LV near the descending thoracic aorta. It is important to recognize this artifact to avoid misinterpretation (Figs 85.23A and B). Few vendors now provide beam-hardening correction algorithms.


A

2039

B

Figs 85.20A and B: Respiration artifact. Breathing-related artifacts can degrade computed tomography angiogram (CTA) studies and cannot be reversed with editing. These images are from the first patient scanned as gated computed tomography (CT) study on 40 detector scanner at our facility. The first image (A) showed a sudden cutoff of the mid-left anterior descending (LAD) which, of course, was not seen at the subsequent cath. When you look at the lung window images at the same level, respiration motion-related artifact is clearly visible as a ghost shadow in the pulmonary vasculature (arrow).

A

B

C

Figs 85.21A to C: Blooming artifacts. Calcium-related blooming artifact (A) remains a problem and is the common cause for calling overstenosis on computed tomography angiogram (CTA). Some newer scanners have different detector material, which helps in suppressing this artifact as shown in image (B). It is not possible to determine stent patency due to severe metal blooming artifact in image (A).

2040


A

B

Figs 85.22A and B: Stent evaluation. Sharper filter or kernel (B) often are very useful to look at the stent lumen and restenosis. The images are very sharp and show the lumen, although at the cost of slightly increased noise in comparison to standard smooth filter use (A).

A

B

Figs 85.23A and B: Beam-hardening artifact. The hypodensity noted near the LV apex (arrow) in this patient was not visualized on the coronal images. This artifact can easily be misinterpreted for myocardial hypoperfusion.

DIAGNOSTIC ACCURACY OF CORONARY COMPUTED TOMOGRAPHY ANGIOGRAM CCTA has become a robust and accurate clinical tool for the noninvasive evaluation of the coronary arteries due

to the high spatial and TR of the current MDCT scanners. The overall performance of the 64-detector CCTA for detecting coronary artery stenosis in comparison to catheter angiography on a patient-based analysis results in sensitivity, specificity, positive predictive values, and negative predictive values of 85–100%, 64–100%, 64–100%,


and 83–100%, respectively.24–31 Improved TR of the dual source scanners has increased the number of evaluable coronary artery segments even in patients with high heart rates.32–38

2041

An acute coronary event often results from plaque rupture and subsequent luminal thrombosis. It is also now suggested that most acute myocardial infarctions result from rupture of nonstenotic vulnerable plaques.41 A vulnerable plaque is often large in size, is lipid rich, has an ulcerated irregular surface with areas of spotty calcifications, and often shows positive remodeling and active inflammation. Many of the features of vulnerable plaque can be determined from CCTA (Figs 85.24A and B). Sato et al. evaluated plaques with CTA in patients with acute coronary syndrome (ACS) and those with stable

angina, and found that in the ACS group the mean density of the plaque was 25 ± 15 H.U. whereas it was 71 ± 16 H.U. in patients with stable angina.42 In their study of plaque evaluation with CT attenuation values, Sun et al. showed clear accurate characterization of calcified plaques, but there was a significant overlap between CT attenuation values of lipid rich and fibrous plaques.43 The authors concluded that at this time, the CT attenuation value is not able to accurately distinguish between lipid-rich and fibrous plaques. The relationship between coronary artery remodeling and plaque composition has been studied and reported by Varnava et al.44 These authors studied 88 male subjects who died with CAD and examined 108 plaques postmortem; 59% had no or positive remodeling and 41% had negative remodeling. They found that there was higher lipid content and macrophage count in plaques with positive remodeling (a marker of plaque vulnerability). In another study, Reilly et al. looked at the effect of statins on human coronary atherosclerotic plaque morphology.45 The authors retrospectively reviewed the arterial sections from native hearts of patients with end-stage ischemic heart disease who received cardiac transplantation (Tx). Thirty-three of 44 study group patients received pre-Tx statins, and 11 did not (which served as control). Both groups were similar in total and low-density lipid (LDL) cholesterol levels, and available number of arterial sections per patient. The prevalence of low-grade fibrous

A

B

CORONARY PLAQUE CCTA is excellent at detecting the presence of atherosclerotic plaques and shows good correlation with intravascular ultrasound (IVUS).39 However, CTs tend to underestimate the volume of a plaque. Leber et al. compared plaque assessment by CTA to IVUS and found that the vessel plaque volume is underestimated by 64-MDCT and its correlation with IVUS was only moderate.40

Plaque Characterization

Figs 85.24A and B: Plaque characterization. Plaque characterization has been investigated and although lower computed tomography (CT) attenuation plaques are presumed to be lipid rich and those with CT attenuation between 40 and 120 are fibrous, there is considerable overlap. At this time it is best to use terms calcified, noncalcified, or mixed plaque for CT descriptions. The CT images in this Figure. belong to two different patients; (A) one with a positive remodeling has noncalcified plaque of CT values of 43, and (B) the other has noncalcified plaque of CT value of 157 and associated negative remodeling.

2042


plaques was much higher (45.7%) in patients receiving statins than those who were not on statins (11.3%). The high-grade lesions were found more frequently in the control group (66.3%) than the study group (34.6%). The authors concluded that statin therapy substantially enhances plaque stabilization due to reduction in plaque inflammation.

PROGNOSTIC INFORMATION FROM CORONARY COMPUTED TOMOGRAPHY ANGIOGRAM The prognostic value of coronary calcification by CT has been well described but the prognostic value of CCTA is less well reported and remains a hot topic.46 Several smaller studies have reported variable outcome from CTA data.47–56 In a recent meta-analysis of 18 studies evaluating 9,592 patients with a mean follow-up of 20 months, the authors concluded that major adverse cardiovascular events (MACE) among patients with normal CTA are rare and there is incrementally increasing future MACE with increasing CAD by CTA.46 In another study, Russo et al. compared the prognostic value of CCTA with that of coronary calcium scoring and clinical risk factors.57 The authors evaluated hard cardiac events in 441 patients who underwent CCTA and calcium scoring for about 32 months. Patients with normal CCTA had a very low hard annualized event rate of < 0.89%, in comparison to 3.89% in patients with any CAD. Obstructive CAD (P < 0.003) and presence of noncalcified or mixed plaque (P < 0.0001) were independent predictors of hard events on multivariate analysis. In another study of 432 patients followed for 24 months, van Werkhoven et al. looked at the incremental prognostic value of CCTA compared with coronary calcium score alone.58 In this study, multivariate analysis demonstrated that the extent of disease and plaque characterization were predictive of cardiac events, specifically plaque burden and plaque composition provided incremental prognostic value over clinical variables and coronary calcium scoring. They also found that 20% of patients with a zero coronary calcium score had noncalcified plaques and 4% patients with no coronary calcium had significant CAD stenosis (> 50%) by CTA, therefore suggesting that coronary calcification alone may not be adequate to accurately assess prognosis. James Min et al. looked at the prognostic value of CCTA for prediction of all-cause mortality in more than 1,127 patients older than 45 years.55 The patient

population included symptomatic patients, those with abnormal stress or rest test as well as asymptomatic ones with peripheral vascular disease (PVD) or multiple risk factors for CAD. The authors identified several prognostically valuable CCTA indices based on visual estimate, modified Duke prognostic CA score, and clinical coronary plaque score.

CARDIAC FUNCTION LV function as reflected by the EF is one of the most important prognostic parameters in patients with CAD. In patients getting retrospective gating, LV assessment can be easily performed with CT data available throughout the cardiac cycle (Fig. 85.25). In a study comparing cardiac function analysis from MDCT with echo, single-photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI), the authors found that there was agreement and similar correlation between CT and MR for EF, enddiastolic volume (EDV), ESV, and LV mass parameters.59 The standard deviation of EF difference between CT and MR was significantly less than that between echo and MR or between SPECT and MR. The evaluation of RV function is more challenging not only because of the shape of RV but also often less than optimal contrast enhancement of the RV when using CCTA protocol.

MYOCARDIAL PERFUSION Although CT is currently not the method of choice to evaluate myocardial perfusion, one can sometimes see perfusion abnormalities in the myocardium in the resting state (Figs 85.26A and B).

Stress Myocardial Imaging Using Computed Tomography In standard current clinical practice, patients with significant coronary artery stenosis detected on MDCT often require additional functional assessment to determine the significance of coronary stenosis, thereby adding more tests, cost, radiation, and patient inconvenience. With improved spatial and TR along with decreased scan time and less radiation exposure, the role of MDCT in evaluating myocardial perfusion is emerging. Several research cardiac CT perfusion studies in animals and human subjects have been published and are proposing MDCT as a useful alternative modality in the evaluation of myocardial


2043

Fig. 85.25: Cardiac functions. In retrospective gated CTA, cardiac function can be derived using CT threshold method and can be displayed in bulls-eye or graphic representation.

perfusion.60–65 Since X-rays are attenuated proportional to contrast concentration in the area of interest, in the absence of beam-hardening artifacts the hypoattenuated myocardial area on CT represents decreased perfusion. Similar to SPECT, one can also use stress induced by adenosine, ragadenoson, or dipyridamole to accentuate the differential myocardial blood flow (MBF) between normal and ischemic areas. Computed tomographic perfusion (CTP) imaging can be performed qualitatively with the more widely available 64-detector scanners or more quantitative dynamic imaging can be done now with 256- and 320-detector scanners. With the latter, time attenuation curves (TACs) of the aorta, LV, and myocardium can be constructed to provide information regarding MBF and myocardial blood volume (MBV) using mathematical models.63 The second generation dual source scanners can also be used

in shuttle and high-pitch mode to derive myocardial perfusion imaging (MPI).64 In a study of 35 patients with a high suspicion of CAD, Rocha-Filho and his group evaluated CTA alone and in combination with adenosine stress perfusion CT for the diagnosis of obstructive CAD on catheter angiography.66 The initial diagnostic performance of CCTA to detect 50% stenosis had a sensitivity of 83%, specificity of 71%, a positive predictive value of 66%, and a negative predictive value of 87%. After including the CTP information, each of these indices improved to 91%, 91%, 86%, and 93%, respectively. Findings were also similar in the 70% coronary stenosis group. The same group also compared the CTP data to SPECT after including a delayed 7-minute prospective CT to determine delayed enhancement and found similar comparative diagnostic accuracy for 70% stenotic lesions.67

2044


A

B

Figs 85.26A and B: (A) Resting myocardial perfusion abnormality. This 45-year-old-male came to the emergency department after being involved in a motor vehicle collision. He had a routine chest/abdominal/pelvis computed tomography (CT). The representative image of the chest CT shows a clear area of hypodensity in the mid to distal septum and apex with CT attenuation values of 33 in comparison to remote lateral wall LV myocardium with a CT value of 68. The wall thickness was maintained. These findings are suggestive of acute myocardial ischemia/infarction and follow-up serial cardiac biomarkers and the electrocardiography (ECG) showed STEMI in the left anterior descending (LAD) distribution; (B) In chronic myocardial infarction there is a subendocardial hypodense defect (arrows) in a vascular territory associated with wall thinning and remodeling as shown in image (B).

HOW TO IMPROVE ACCURACY OF COMPUTED TOMOGRAPHY ANGIOGRAM IN DETERMINING FLOW LIMITING DISEASE In a recent study done in 381 patients using a 320-detector scanner, Lima et al. have shown the added value of CT perfusion data to routine CCTA to increase the diagnostic accuracy of the CTA to define flow-limiting CAD at a lower radiation dose when compared with conventional invasive angiogram and MPI combined.68 CT-based fractional flow reserve (FFR-CT) calculation is another upcoming promising method to determine noninvasively the significance of any coronary artery stenosis. Computational fluid dynamics (CFDs) is used to calculate pressure gradients across stenotic areas on standard CCTA studies. In a multicenter DeFACTO study, the authors compared FFR-CT with invasive FFR in 252 patients and found that there was improved diagnostic accuracy and ability to determine functionally significant stenosis by using FFR-CT in conjunction with CCTA over CTA alone (AUC: 0.81 vs 0.68 respectively, P < 0.001).69 This promising method is currently limited by the long time (up to several days) taken to compute huge data but hopefully will be available one day soon for it to be applicable in clinical practice.

CLINICAL INDICATIONS Coronary Calcium Scoring Quantification of CAC burden on CT is shown to be an independent, noninvasive marker and predictor of adverse cardiovascular (CV) events in asymptomatic individuals.70 The risk assessment on CT CAC extends beyond that provided by the Framingham risk score to a population with a wide ethnic background.70 Thus, CAC has the potential to restratify intermediate risk groups into lower or higher groups. Prospective ECG-gated cardiac images are acquired with a slice thickness of 2.5–3 mm without intravenous contrast. The FOV extends from just below the carina to cardiac apex. Coronary calcium is defined as an area of at least three adjacent pixels in the axial plane in the course of a coronary artery, with an attenuation threshold value of 130 H.U. or greater. Three in-axial-plane face-connected pixels correspond to a minimum lesion area > 1 mm2, which is used as a reference value in calcium scoring.71 There are currently two CT calcium scoring systems widely used: the original Agatston method and the volume scoring method developed by Callister et al.71,72 These images are postprocessed on a dedicated 3D workstation with appropriate software that automatically detects calcium on all CT slices (Fig. 85.27).


2045

consensus regarding the calcium score beyond which CCTA should not be performed. Some authors suggest a value of 600 while others, 1,000. In our opinion what is more important is the distribution of the coronary calcium, since a CCTA can still be useful if the calcium is concentrated in a few coronary segments leaving many other segments evaluable as shown in Figure 85.28.

Acute Chest Pain Evaluation with Multidetector Computed Tomography in the Emergency Department Setting Fig. 85.27: Coronary calcium score. Calcium scores are calculated by the computer based on selected H.U. threshold calcifications and the numbers tabulated in different vascular distribution as shown here.

In Agatston’s scoring method, the calcium area is multiplied by a number related to CT attenuation. Partial volume effects lead to higher peak values for small calcific lesions but not for large ones. Whereas, the volume scoring method appears to somewhat resolve the issue of a section dependent on minor changes in section thickness. However, excellent correlation has been demonstrated between the two scoring methods.73 Both methods calculate lesion-specific scores within the left main, LAD, left circumflex, and right coronary arteries and provide total scores for an individual artery as well as total score across all four arteries. When CAC scan is performed just preceding the CCTA, it can serve as a gatekeeper to exclude cases with heavy calcification because of low diagnostic yield. However, there is no established absolute number of CAC score above which CCTA should not be performed. Secondly, it also serves as a reference scan to tighten the CCTA FOV in craniocaudal direction. The expert consensus document by the American College of Cardiology Foundation and the American Heart Association regarding the current role of CAC testing in clinical practice among asymptomatic individuals states, “It may be reasonable to consider use of CAC measurement in asymptomatic individuals who are at intermediate risk.”74 However, the committee did not find enough evidence regarding the utility of CAC testing in further risk-stratifying in those considered at high risk of developing CAD in the next 10 years.74 There is no

Despite recent advances in medical sciences, the evaluation of acute chest pain presenting in the emergency department (ED) is difficult and remains a diagnostic challenge. In a study of more than 10,000 chest pain ED patients, 2.1% with acute MI and 2.3% with acute unstable angina were inappropriately discharged.75 Due to medicolegal issues, many of these patients with chest pain get admitted unnecessarily for further tests and investigations leading to billions of dollars of excessive cost each year.76 In this scenario, a test with a very high negative predictive value, such as CCT angiography, can be very useful in effectively triaging this cohort of patients. A major limitation, especially in acutely ill patients, is the quality of the images especially if the patients have tachycardia. Administration of -blockers, which is a standard practice for CCT angiography, is time consuming, is limited by contraindications, and may not be effective in many acutely ill patients. Initial studies of dual source CT have shown a very good diagnostic accuracy of CCTA, even with a high heart rate.33,77 Improved assessment of coronary arteries with CT and easy accessibility and close proximity of ED to such scanners has increased the interest in MDCT evaluation of chest pain. With 64-detector CT, sensitivity and specificity rates of > 90% have been reported with few nonevaluable segments than with earlier generation MDCT scanners.28,30,78 A recent blinded prospective study of 103 patients with chest pain who presented to the ED showed absence of significant coronary stenosis and presence of nonsignificant atherosclerotic plaque by MDCT, suggesting absence of ACS, giving a negative predictive value of 100%.79 In another study, MDCT compared favorably with radionuclide perfusion imaging for detecting ACS in 92 low-risk patients with chest pain in the ED.75

2046


Fig. 85.28: Coronary calcification. The cutoff coronary calcium is reported to be between 600 and 1,200. However, computed tomography angiogram (CTA) still could be useful if the calcification score for not performing CTA is limited to a few segments and it can also show noncalcified lesions elsewhere as in these images. This patient had a calcium score of 1,060 causing mostly nonobstructive disease, but there was additional more significant stenosis in the distal RCA due to mostly noncalcified plaque (red circle).

Meijboom et al. evaluated the role of 64-MDCT in 254 symptomatic patients with an estimated pre-test probability of CAD to be high (N = 105) in 87%, intermediate (N = 83) in 53%, and low (N = 66) in 13%, using the Duke Clinical Scoring System.80 The estimated posttest probability of the presence of significant CAD after a negative CT scan was 17%, 0%, and 0%, respectively, and after a positive CT scan was 96%, 88%, and 68%, respectively. Based on these findings, the authors suggested the usefulness of MDCT in symptomatic patients with low or intermediate estimated pre-test probability of having significant CAD. CT did not provide additional relevant diagnostic information in high pre-test probability symptomatic patients. In a prospective randomized trial of 197 patients with acute chest pain at low risk for ACS presenting to the ED,

Goldstein et al. compared the safety, diagnostic efficiency, and cost effectiveness of 64-detector CT with standardof-care diagnostic evaluation.81 In 75% of patients, physicians were able to rapidly triage by immediately excluding or identifying coronary disease using MDCT. In the remaining 25% of patients, further nuclear stress testing was performed due to either nondiagnostic MDCT scans or the presence of intermediate severity lesions. No adverse coronary events were identified for 6 months in patients who underwent MDCT comparable to the other group with the standard-of-care approach. The average time in the diagnostic evaluation of patients was 3.4 hours in the MDCT group compared to 15 hours in the standardof-care evaluation group. The average cost of patients was modestly lowered $1,872 to $1,586, when the MDCT algorithm was used.


Several authors recently have investigated the value of calcium scoring, especially with EBCT to triage ED chest pain patients.82–84 In one such study of 105 patients with possible ACS with normal cardiac enzymes and a nondiagnostic ECG result, Laudon et al. found the overall sensitivity, specificity, and negative predictive value for a positive finding (non-zero calcium score) at EBCT to be 100%, 63%, and 100%, respectively.82 No patient with a negative EBCT had any cardiac event at 4-month follow-up.

Techniques of Multidetector Computed Tomography for Acute Chest Pain Evaluation in Emergency Department Two different protocols are described. First is a dedicated standard CCT angiography protocol, which includes prospecitve gating and small FOV. The advantage of this protocol is improved SR to evaluate coronary arteries with less contrast and radiation dose. The disadvantages include nonvisualization of other potential causes of chest pain in the lungs and mediastinum not included in the FOV. In the second “triple rule out” protocol, the entire chest is scanned using a gated technique, but with a large FOV leading to increased contrast dose, and increased scan time. The advantage of this protocol is evaluation of other potential causes of chest pain as described above. There is no consensus regarding use of these protocols or regarding a preference to use these protocols. However, in a given patient, if there is a strong suspicion for CAD or the main issue is excluding CAD, a dedicated CTA protocol is preferred. On the other hand, in patients with atypical chest pain, without definitive CAD suspicion, a “triple rule out” may suffice. Two recently published large trials ACRIN-PA and ROMICAT II collectively recruited 2,370 low- to intermediate-risk patients presenting with suspected ACS to the ED in the United States and compared protocols including an early CT with traditional care group.85,86 The authors concluded that there was a significant reduction in the length of stay and increased discharge rate from the ED in the CT group without any adverse outcome. In CT-STAT trial, 699 patients at 16 EDs were randomized to either CCTA or MPI.87 All of the patients had symptoms of ischemia but a normal or nondiagnostic rest ECG, no previous known coronary disease, a low

2047

TIMI score, and no other obvious indicators of ACS such as elevated biomarkers or arrhythmia. Over 6 months of follow-up, the patients imaged with CCTA were diagnosed 54% faster than those imaged with MPI (median 2.9 hours vs 6.3 hours, P < 0.0001). The total costs of care were 38% lower with the CCTA group (median $2,137 vs $3,458, P < 0.0001), even though the cost of each MPI test itself was only a little more than the cost of each CCTA ($538 vs $507). The diagnostic strategies made no difference in MACE rate (0.8% in the CCTA arm vs. 0.4% in the MPI arm, P = 0.29). The CCTA patients were also exposed to less radiation than the MPI patients (11.5 mSv vs 12.8 mSv, P = 0.02).

Anomalous Coronary Artery Evaluation Coronary artery anomalies are rare (0.3–1%) and are often asymptomatic. Malignant form of anomalies can be symptomatic presenting with syncope, arrhythmia, chest pain, or sudden death. MDCT is now considered the gold standard method to evaluate patients with suspected coronary artery anomalies with an appropriate use criteria score of A 9.20 Anomalies of coronary arteries can be classified as anomalous origin, anomalous proximal course, or anomalous termination (Figs 85.29 to 85.32). Among the abnormal courses, the interarterial course is most dangerous and has been implicated as one of the causes of sudden death in young

Fig. 85.29: Coronary artery anomaly. The most common anomaly is high origin of the right coronary artery above the sinotubular junction as shown in this image (arrow). (L: Left cusp; R: Right cusp).

2048


Fig. 85.30: Single coronary artery. In this patient presenting with atypical chest pain, coronary computed tomography angiogram (CCTA) showed a large single coronary artery (arrow) arising from the right cusp and supplying all territories of right and left circulation. Whenever one of the coronary artery is significantly larger than normal, one should look for obstructive disease in other vessels, coronary artery fistula, or anomalous coronary artery origin from a low pressure system such as a pulmonary artery.

Fig. 85.31: RCA from left cusp. Sagittal oblique CT image shows anomalous origin of the right coronary artery from the left cusp and has interarterial course between aorta and pulmonary artery (arrows). (L: Left cusp; NC: Noncoronary; PA: Pulmonary artery; R: Right cusp).

Fig. 85.32: Volume rendering (VR) image clearly shows the empty right cusp and anomalous origin of the right coronary artery from left cusp. Due to the proximity of the anomalous vessel to commissure and proximal intramural course unroofing procedure can be done in such cases with good results. (L: Left cusp; NC: Noncoronary; R: Right cusp).

Fig. 85.33: Anomalous origin of left coronary artery from pulmonary artery (ALCAPA). A 25-year-old female with increasing shortness of breath. Oblique volume–rendered image demonstrates the anomalous origin of the left coronary artery from the pulmonary artery (red arrow). The RCA (white arrow) is much larger.

patients. The prepulmonic course is often seen in patients with tetralogy of Fallot (TOF) and should be identified preoperatively so as to avoid directly cutting into it on the operating table. Anomalous origin of left main coronary artery from the pulmonary artery (ALCAPA) is a rare anomaly and often

presents early in life with chest pain or dilated ischemic cardiomyopathy (Fig. 85.33). Table 85.12 describes the methods to optimize evaluation of a suspected coronary artery anomaly. Coronary artery fistula is rare, commonly congenital, and can be coronary-cameral fistulas (between coronary


2049

Table 85.12: Optimization of Anomalous Coronary Artery Computed Tomography Angiogram Protocol

In a younger age, restrict field of view (FOV) For interarterial course, show pulmonary valve relation (good to have some contrast in right circulation) Volume rendering (VR) images show spatial relationship nicely Multiplanar reformation (MPR)/thin maximum-intensity projection (MIP) images needed to document intramural course and oblique narrow takeoff of the anomalous vessel

artery and cardiac chambers), coronary arteriovenous (AV) malformation (between coronary artery and low pressure veins), drainage often to RV, RA, or pulmonary arteries, and less frequently to superior vena cava (SVC), coronary sinus, or LA (Fig. 85.34). Rarely, coronary artery fistula develops from acquired causes such as trauma or invasive procedures (pacemaker placement, endomyocardial biopsy) or CABG. Most are small and the patient, asymptomatic. On examination, a continuous murmur can be heard at the left lower sternal border and the CA branches proximal to the shunt become enlarged. Smaller fistulas in children tend to grow with age. If left untreated, they can cause symptoms in 19% of patients under the age of 20 years and in over 60% of older patients. Small fistulas in an asymptomatic patient should be followed clinically for signs of growth and increasing flow. The larger hemodynamically significant fistulas should be closed either surgically or via transcatheter occlusion techniques especially if the fistula is short and less tortuous. Sequelae of coronary artery fistula may include chronic angina, congestive heart failure (CHF), cardiomyopathy, myocardial infarction (MI), hypertension (HTN), endocarditis, and rarely fistula rupture.

Preoperative Computed Tomography Angiogram When catheter angiography is considered dangerous, difficult, or contraindicated, such as patients with aortic vegetations, ascending aortic dissection and those with massive aortic dilatation making it very challenging to canulate coronary ostia (Figs 85.35A to C).

Re-do Coronary Artery Bypass Graft This is another common indication and can be performed with or without intravenous contrast depending on the clinical question (Figs 85.36A and B).

Fig. 85.34: Coronary artery (CA) fistula. LV to OM branch fistula in a patient after MI is seen on the axial computed tomography angiogram (CTA) image. (LV: Left ventricle; RV: Right ventricle).

Role in Asymptomatic Intermediate Risk Patient Currently, CTA is not indicated for asymptomatic individuals and this is a topic of hot debate. One school of thought leans toward getting CTA in patients with significant risk factors including family history of premature atherosclerosis. In a large multicenter registry study, Chinnaiyan et al. presented their research data from the advanced CV imaging consortium (ACIC) in Michigan looking at the CCTA in asymptomatic individuals.88 A total of 21,573 patients without known CAD participating in ACIC at 43 institutions in Michigan were included and of these 11.8% were asymptomatic and 88.2% were symptomatic.89 The asymptomatic group patients were older, had more males with higher Framingham risk scores, and higher frequency of abnormal stress tests (38% vs 21%). CCTA in these patients showed a lower frequency of normal coronary arteries (38% vs 51.2%) and higher frequency of both < 50% and > 50% luminal stenosis. The authors concluded that the asymptomatic patients had worse risk profiles and a higher CAD burden on CCTA. These findings have broad implication on identification of candidates for aggressive secondary prevention. The main hurdle in our view has been the issue of radiation exposure, which is understandable. But with the recent advances and availability of very low dose CTA protocols it seems logical and appropriate to use CTA selectively in such high-risk populations with radiation exposure close to or < 1 mSv. In fact, with such low-dose scanning capability, it is possible that in the near future

2050


A

B

C

Figs 85.35A to C: Preoperative computed tomography angiogram (CTA). Preoperative CTA is done when catheter angio is difficult or dangerous; (A) ascending aortic aneurysm and dissection in a patient with previous coronary artery bypass graft (CABG); (B) ascending aortic dissection narrowing the LM ostium (arrow); (C) aortic valve endocarditis as seen on echo and computed tomography (CT) images (arrow).

CTA might play an important role as a screening modality for CAD somewhat similar to where we stand now for screening of lung cancer using low-dose CT.

Coronary Artery Bypass Graft Gated cardiac CT is well suited to evaluate patency of bypass grafts noninvasively, since these grafts are usually larger diameter structures and there is less cardiac motionrelated artifacts. The reported sensitivity and specificity for detecting stenosis or occlusion is 95–100%.90 With the newer scanners, the anastomosis can be well evaluated with less motion, less metal clip hardware artifact, and better vascular opacification (Figs 85.37A to C). The CTA protocol needs to include the entire chest, especially the subclavian arteries if the patient has had internal mammary grafts. More contrast is often needed and the breath hold is slightly longer (Figs 85.38A and B).

Coronary Stent Evaluation The population needing follow-up of PCI is growing and follow-up of stents with catheter angio is expensive and carries risks. Currently, clinical symptoms and/or provocative tests are noninvasive tools with no direct stent imaging capability available. In a study comparing the diagnostic accuracy of coronary in-stent stenosis using a 64-detector CT with invasive coronary angiography, the authors reported high sensitivity, specificity, and negative predictive values of 92% and 90%, 81% and 79%, and 98% and 96% per segment/per patient basis, respectively.91 The positive predictive value, however, was only modest at 54% and 58%, respectively. Several steps that can be taken to improve in-stent visualization are the use of higher mAs to improve contrast resolution, use of high intravascular attenuation, use of sharper kernel, and lowering of the heart rate (Figs 85.39A to C).


A

2051

B

Figs 85.36A and B: Redo sternotomy. Performing computed tomography (CT) is an appropriate indication for a patient being evaluated for redo CABG or noncoronary cardiac surgery. CT can accurately detect the distance of vital structures near the sternum as well as the presence of any adhesions. In the images here, this patient had developed a pseudoaneurysm (PSA) at the site of aortic cannulation (arrows) done for cardiopulmonary bypass. Computed tomography angiogram (CTA) clearly showed the close proximity of the PSA to the sternum, which is useful information for the surgeons in planning a safe surgical approach.

Cardiac Masses Primary cardiac tumors are rare but metastases to the heart from other locations are much more common. Primary benign tumors are much more common than primary malignant neoplasms. Myxoma is the most common primary benign cardiac neoplasm in adults. Most myxomas arise in the LA near the fossa ovalis and less commonly from the atrial free wall or atrioventricular valve. Less commonly they can arise in the RA or RV. On CT, myxomas are round, smooth, and lobulated masses often with a pedicle and demonstrate patchy postcontrast enhancement. Often these masses have areas of calcifications as well as low attenuation (Fig. 85.40). On a retrospective gated CT, the pedunculated myxoma can be seen to prolapse through the mitral valve. Symptoms from myxoma are usually due to hemodynamic obstruction, embolism, or rarely constitutional symptoms. Multiple cardiac myxomas can be associated with pigmented skin lesions, extracardiac tumors (schwannoma, pituitary adenomas), and endocrine abnormalities (Carney’s complex). Lipoma is the second most common primary benign cardiac tumor. It can either arise from the subendocardial layer or subepicardial/myocardial layer. The endocardial

lipomas are usually small and most commonly seen in the LV or along the septal wall or roof of the RA. Usually, these are asymptomatic and detected incidentally on cross-sectional imaging or rarely can cause symptoms if large in size, usually by obstructing a cavity, extrinsic mass effect, or causing arrhythmia. On CT, these tumors are well defined, noncalcified, and nonenhancing masses with fat CT attenuation values (Figs 85.41A and B). Fibroma is the second most common primary benign tumor of the heart in children after rhabdomyoma. These tumors are less commonly seen in adults and more commonly arise from LV than RV in the interventricular septum or anterior ventricular wall. On CT, they are homogenous intramyocardial masses, often calcified with little or minimal enhancement after contrast administration (Fig. 85.42). Patients can present with dysarrhthymia, chest pain, or sudden death. Several syndromes are associated with cardiac fibromas including Gardner, Gorlin, and familial adenomatous polyposis. Fibroelastomas account for approximately 10% of cardiac tumors and 75% of valvular neoplasms.92 Most arise from the endocardium of aortic, mitral, tricuspid, and pulmonary valves (in decreasing order) and are often solitary, small nodular masses, mimicking vegetation,

2052


A

B

C

Figs 85.37A to C: Coronary artery bypass graft (CABG) volumerendering (VR) image. (A and B) Proximal and distal anastomosis (circle) with good distal flow from LIMA to posterior descending artery (PDA) graft; (C) Multiple grafts are seen including left internal mammary artery (LIMA) and two venous grafts. Metal clips are actually not causing much metal streak artifact. (LSC: Left subclavian artery).

A

B

Figs 85.38A and B: Coronal oblique computed tomography angiogram (CTA) image (A) shows the opacified LIMA with patent distal anastomosis with diagonal branch (circle) and distal flow. The corresponding cath angio view (B) confirms these findings.


2053

A

B

C

Figs 85.39A to C: (A) Mild in-stent narrowing in mid-left anterior descending (LAD) stent (arrows); (B and C) Stent occlusion in saphenous venous graft (SVG) graft as shown in two orthogonal images.

thrombus, and myxoma on imaging. Due to their small size, these tumors are difficult to visualize on CT. In comparison to a vegetation, fibroelastoma usually spares the valve-free margin. They can be detected incidentally in an asymptomatic patient or rarely can cause symptoms due to embolization or rarely coronary ostial obstruction. Metastasis is the most common malignancy of the heart occurring in approximately 10–12% of patients with extracardiac malignancy.93 Several tumors have the propensity to metastasize to the heart including melanoma, lung, breast, thyroid, renal, and esophageal cancers (Figs 85.43A and B). Tumors can spread to heart via hematogenous, direct, transvenous, or translymphatic invasion. Direct invasion occurs usually with lung, breast, Fig. 85.40: Left atrium (LA) myxoma. Axial computed tomography or other mediastinal tumors and usually manifests as (CT) image shows a homogenous noncalcified mass (arrow) in pericardial effusion and thickening. Venous extension of the left atrium attached to the interventricular septum. (AO: Aorta; the renal and adrenal carcinoma occurs via the inferior LV: Left ventricle RV: Right ventricle). vena cava (IVC), whereas lung cancer can extend into the

2054

A


B

Figs 85.41A and B: Lipoma. A large fat-computed tomography (CT) density mass (arrow) is seen in the right atrium extending up to the superior vena cava (SVC) to right atrium (RA) junction superiorly as seen in image (B). (AO: Aorta; LV: Left ventricle; PA: Pulmonary artery).

sarcoma occurring more commonly in females between 20 and 50 years of age. The most common site of cardiac angiosarcoma is RA, while other sarcoma types tend to occur more on the left side (Figs 85.44A and B). These tumors appear as irregular nodular soft tissue masses with infiltration into the pericardium with postcontrast heterogenous enhancement. They also tend to involve more than one chamber by direct infiltration. Often there is associated pulmonary metastasis in approximately two-thirds of patients. Pericardial cysts are the result of blind-ended ventral parietal pericardial recesses. Most patients are asymptomatic and only rarely cause chest pain or dyspnea. The most common location is cardiophrenic angle, 80% on the right side. On CT, they appear as well-defined fluid Fig. 85.42: Cardiac fibroma. There is a calcified intramyocardial mass arising in the left ventricular lateral wall (arrow). Cardiac density smooth masses, which show no enhancement after contrast (Figs 85.45A and B). fibromas are common in pediatric age groups. Lipomatous hypertrophy of interatrial septum occurs usually in older obese patients and are mostly heart via pulmonary veins. Solitary cardiac metastasis asymptomatic. On CT, the interatrial septum is thickened is rare and hematogenous metastasis often is associated > 20 mm with fat and is dumbbell-shaped with sparing of with other organ metastasis. The masses are often irregular the FOV (Figs 85.46A and B). and demonstrate heterogenous enhancement. Lymphoma of the heart is often secondary rather than a primary cardiac tumor. Primary cardiac lymphoma is Pulmonary Vein Ablation often the more aggressive non-Hodgkin B-cell, tends to Atrial fibrillation (AF), the most common sustained occur at an older age and in patients with HIV infection. cardiac arrhythmia, is a major cause of stroke and the most Common sites of involvement include pericardium, RA, common cardiac arrhythmia requiring hospitalization. and AV groove. AF usually begins as paroxysmal AF, with approximately Sarcoma is the most common primary cardiac 60% of patients converting spontaneously to normal sinus malignancy. Angiosarcoma is the most common type of rhythm. Approximately 40% of patients develop persistent


A

2055

B

Figs 85.43A and B: Metastasis. Metastasis from melanoma involving the pericardium (star) aortic root and interventricular septum (arrow).

A

B

Figs 85.44A and B: Angiosarcoma. Angiosarcoma of the heart (star) involving right ventricle (RV) and extending across the right atrioventricular (AV) to involve the right atrium (RA).

A

B

Figs 85.45A and B: Pericardial cyst. A well-circumscribed water density nonenhancing mass is seen along the right atrium (RA).

2056


A

B

Figs 85.46A and B: Lipomatous hypertrophy of the interatrial septum. Lipomatous hypertrophy of the interatrial septum often spares the fossa ovalis and produces a dumbbell-shaped appearance as shown in image (red circle). The fatty component can extend into the right atrial wall to a variable degree and can sometimes encroach on the cavoatrial junction (arrow), although usually without any hemodynamic consequences. (AO: Aorta; LA: Left atrium; LV: Left ventricle; RA: Right atrium: RV: Right ventricle; RVOT: Right ventricle outflow tract).

AF requiring medical or procedural intervention to restore normal sinus rhythm. Up to 50% of patients develop recurrent AF within the first year of initial onset. Radiofrequency catheter ablation of the pulmonary vein ostia has become the procedure of choice for treating AF. CT plays an important role in the evaluation of these patients including pulmonary venous anatomy and any variation before the procedure, and detecting postablation complications. Prospective gating is suitable for the majority of patients except those with a very high heart rate or obese patients, where either retrospective gating with tube current modulation or a nongated chest CTA is an option since motion-related artifacts are not an issue for pulmonary veins and LA. The most common normal pulmonary venous pattern (75–80%) is two right and two left pulmonary veins (superior and inferior) with a separate ostia for each vein. The pulmonary ostium is defined as the junction point of the pulmonary vein and LA at the point of parietal pericardium reflection over the LA. The pulmonary vein segment from the ostia to its first branch is called pulmonary vein trunk and the region of left atrial wall in between the two separate ipsilateral pulmonary veins is called the intervenous saddle. The pulmonary vein ostia and the intervenous saddle together are known as pulmonary venous vestibule. Pulmonary venous branching is more variable than pulmonary artery (PA) branching variations and includes variation in number, branching pattern, and

length of the pulmonary trunk. MDCT is useful in detecting these pulmonary vein variations, knowledge of which is vital for successful and complete ablation procedure. Paroxysms of AF are initiated by trains of spontaneous activity originating from the pulmonary veins (90–96%), with almost half arising in the left superior pulmonary vein. In most individuals, sleeves of the left atrial myocardium extend into the pulmonary veins for a distance of 2–17 mm. The myocardial sleeve of the LA surrounding the proximal pulmonary venous segment and venoatrial junction are believed to be the source of initiation and maintenance of AF.94 Since the myocardial sleeve is longest around the left superior pulmonary vein, this vein alone contributes to > 50% of all ectopic beats for AF. Radiofrequency ablation is performed at or within 5 mm of the pulmonary vein ostia; therefore, it is important to know the number of pulmonary veins and branching pattern to ensure ablation of all ostia. Successful ablation of all electric connections to these veins can eliminate paroxysmal AF. Because radiofrequency energy is preferably applied at the venoatrial junction of all the pulmonary veins to avoid stenoses and eliminate ostial remnants that may contribute to recurrent AF, knowledge of how many pulmonary veins are present, and their ostial locations, is important to ensure that all the ostia are ablated. However,


it is difficult and time-consuming to locate the ostia with conventional angiography at the time of ablation. It is important to know ostial orientation and the distance from each ostium to the bifurcation of each pulmonary vein, because pulmonary vein narrowing seems to be critically dependent on catheter position and not on duration of radiofrequency energy application. Planning CT is done to determine the number of PVs and ostia, PV diameter and length to its first order branch, accessory veins and the presence of any LAA thrombus (Figs 85.47 to 85.49).

Fig. 85.47: Segmented left atrium posterior view shows the draining pulmonary veins. (LLL: Left lower lobe; LUL: Left upper lobe; RLL: Right lower lobe; RUL: Right upper lobe).

A

2057

Transcatheter Aortic Valve Replacement Transcatheter aortic valve replacement (TAVR) is rapidly becoming a popular alternative procedure for older patients with severe symptomatic aortic stenosis, who are at high risk for open surgical repair. Several prosthetic valves are available including the balloon expandable Edwards Sapien Valve (Edwards Lifesciences Inc, Irvine, CA, USA) in 23, 26, and 28 mm sizes and self-expanding CoreValve (Medtronics Inc, Minneapolis, MN, USA) available in 23, 26, 29, and 31 mm sizes. In the United States, only the 23- and 26-mm Edwards valves are currently approved. The most common implantation route is transfemoral. If this is not feasible, the Edwards Sapien valve can be implanted via direct transapical approach or rarely via a transaortic approach. Currently, this system is not approved for subclavian artery approach. Imaging is necessary before the procedure to determine annulus size, annulus area, degree of aortic calcification, access route, and suitable fluoroscopic projection angles that permit exact orthogonal views onto the valve. Preprocedural assessment of the aortic root for TAVR requires knowledge of the orientation of the aortic root relative to the body axis. For correct deployment of a percutanous valve prosthesis, the root orientation is usually assessed by repeated X-ray aortograms in one or two orthogonal planes. To simplify the procedure, 3D data sets obtained by MDCT may allow the prediction of angiographic projections orthogonal to the valve plane (Figs 85.50A to C).

B

Figs 85.48A and B: PV ablation. Computed tomography angiogram (CTA) images are loaded into PV ablation software in the cath lab and are fused with cath images to show the catheter location in relation to the left atrium (LA) and its veins. The electrical map is then generated and shows as red dots (B), which need to be ablated. (LIPV: Left inferior pulmonary vein; LSPV: Left superior pulmonary vein; RIPV: Right inferior pulmonary vein; RSPV: Right superior pulmonary vein).

2058


Fig. 85.49: Left atrial appendage (LAA) thrombus. This image shows a patient with LAA thrombus (*) with chronic atrial fibrillation. Presence of thrombus is a contraindication for an ablation procedure. (AO: Aorta; PA: Pulmonary artery).

A

B

C

Figs 85.50A to C: Computed tomography angiogram (CTA) for transcatheter aortic valve replacement (TAVR). CT plays an important role in preoperative planning of TAVR patients, annulus size (A) and area can be determined along with distance of LM and right upper lobe (RUL) to annulus (B) and (C).


CT imaging is the preferred method to evaluate the aortic root, entire aorta, and iliac as well as common femoral arteries preferably with single contrast injection. Since most such patients are older and have some renal impairment, it is preferable to do complete analysis with a single contrast bolus. At our institution, we use 70–100 cc of contrast for a retrospective gated chest from arch till diaphragm and then a nongated CTA of the abdomen and pelvis, (Table 85.9). Given the advanced age of the patient, radiation exposure is of lesser concern after some modifications for minimum recommended vessel lumen size for different delivery systems.95 Accurate annulus size measurement is very important in choosing the correct size of the prosthetic valve. A valve that is too large can cause rupture of the annulus, which is often fatal and if the valve is too small, there is a risk of embolization and paravalvular leak.96–98

Congenital Heart Disease CT plays an important role in the evaluation of patients with known or suspected CHD. With the advances in surgical techniques and CV anesthesia along with perioperative care, many patients with complex CHD now survive into adulthood. Majority of these patients need lifelong care including reoperations from underlying anatomy or previous surgical palliative procedures. Careful preparation is important for CT evaluation of pediatric and adult CHD. The CT protocol should be selected on a case by case basis depending on the suspected anomaly. In neonates/infants, cardiac gating is a challenge due to higher heart rates. To minimize other artifacts, we routinely intubate them and suspend their respiration during the few seconds of nongated CT scanning. To avoid physical movement, the child is also given some form of sedation or muscle paralytics. We use approximately 1 cc/lb of contrast and dilute it with 50% saline, and the injection is made with hand. A central umbilical venous catheter (UVC) catheter positioned just below the cavoatrial junction is preferred, although a peripheral access also suffices the need for vascular opacification. In adults, the protocol includes a gated CTA preferably with controlled heart rate. A systematic segmental approach is the best method to evaluate complex CHD by CTA as follows: (a) determine atrial situs derived from bronchial branching pattern (b) locate the three segments (the atrial chambers, ventricular chambers, and the great arteries), (c) identify the cardiac connections (venoatrial, atrioventricular, and ventriculoarterial), (d) assess associated malformations,

2059

and (e) determine the cardiac position (position of the heart within the chest, orientation of the apex). Due to complexity of CHD, CT images often require evaluation on a dedicated 3D workstation.

Atrial Septal Defect Atrial septal defect (ASD) accounts for about one-third of cases of CHD detected in adults.99 Ostium secundum atrial septal defects are the most common type of interatrial communication located at the fossa ovalis (Figs 85.51A to D) and ostium primum atrial septal defects are the next most common type, the least common type of interatrial communication is a sinus venosus defect, which is located at the junction of either the superior or the inferior vena cava with the RA. In patients with a superior sinus venosus defect, there is frequently an abnormal connection of one or all of the right pulmonary veins (Figs 85.52A and B).100

Anomalous Pulmonary Venous Connection Patients with total anomalous pulmonary venous connection are often evaluated in early childhood, especially the infracardiac variety, which is often associated with obstruction of the vertical vein at the diaphragm leading to pulmonary venous HTN and edema. In partial anomalous pulmonary venous connection, one or more (but not all) pulmonary veins are connected to the vena cava or RA (Fig. 85.53). Abnormal connection of the right upper pulmonary vein to the SVC occurs frequently in the presence of a sinus venosus defect. Anomalous connection of the right pulmonary vein or veins to the IVC, often seen in association with hypoplasia of the right lung and anomalous systemic arterial supply through aortopulmonary collateral vessels, is called scimitar syndrome.

Transposition of Great Arteries The majority of adult patients with this condition have undergone corrective surgery either atrial or arterial switch operations. In the atrial switch procedure, an atrial baffle redirects systemic venous blood to the anatomical left pulmonary ventricle and pulmonary venous blood to the anatomical right systemic ventricle, with a resultant functional atrial switch. The Mustard operation usually is performed with pericardial tissue or a tissue graft used for the baffle, whereas in the Senning procedure, the atrial septum is reconstructed to form the baffle (Figs 85.54A to D).101 In the arterial switch operation, the aorta and the

2060


A

B

C

D

Figs 85.51A to D: Atrial septal defect (ASD) and Eisenmenger syndrome. Chest radiograph (A) shows an enlarged heart, dilated pulmonary arteries, and shunt vascularity. Axial computed tomography (CT) image (B) shows a large septum secundum defect (circle) along with a dilated right atrium. The main pulmonary artery is dilated (C) and there is mosaic perfusion in both lungs (D). Findings are suggestive of secondary pulmonary HTN. (LA: Left atrium; LV: Left ventricle; RA: Left atrium; RV: Right ventricle; MPA: Main pulmonary artery).

A

B

Figs 85.52A and B: Sinus venosus atrial septal defect (ASD). A connection is seen between distal superior vena cava (SVC) and roof of the left atrium (A, red arrow) along with anomalous right upper lobe (RUL) pulmonary vein drainage into the SVC (B, yellow arrow). (AO: Aorta; LA: Left atrium; RA: Right atrium; RV: Right ventricle; RAA: Right atrial appendage; PA: Pulmonary artery; PV: Pumonary valve).


2061

Fig. 85.53: Coronal computed tomography (CT) angio view. Partial anomalous pulmonary venous return (PAPVR) of right lung into inferior vena cava (IVC; arrow) is responsible for secondary pulmonary artery hypertension (PAHTN) in this 48-year-old female presenting with progressive shortness of breath and was responsible for secondary pulmonary HTN. This patient was operated successfully. (RA: Right atrium).

A

B

C

D

Figs 85.54A to D: Transposition of great arteries (TGA) status post (s/p) Senning operation. The pulmonary artery (PA) is to the left and slightly posterior to the aorta (AO). It is connected to the morphological left ventricle (LV). An intra-atrial baffle (B) is connected to the LV. The aorta is connected to the morphological right ventricle (RV), which is hypertrophied and dilated. The morphological left atrium is surgically connected to the RV, thereby correcting the blood flow: systemic venous blood flows via the baffle (star) into the LV then into PA and lungs. The oxygenated blood returns via the pulmonary veins into the LA and is directed into the RV and then into the aorta.

2062


PA are transected above the semilunar valves and moved to the correct circulatory position. The coronary arteries are excised from the right side with a button-like margin of tissue around each artery and are implanted just above the valve on the left side of the heart; the areas from which the coronary arteries were excised are then patched with pericardium. Postoperative evaluation after an atrial switch procedure may be difficult with echocardiography because of the retrosternal position of the pulmonary trunk and pulmonary arteries.

Congenitally Corrected Transposition of the Great Arteries In this condition, there is discordant atrioventricular and ventriculoarterial connections, such that the morphological RA is connected via the mitral valve to the morphological right-sided LV and then to the PA. The morphological LA is connected via the tricuspid valve to the morphological left-sided RV and then to aorta (Figs 85.55A and B). In patients with congenitally corrected transposition, the great arteries are parallel (side-by-side arrangement). In the absence of associated anomalies (e.g. ventricular septal defect, pulmonary outflow tract obstruction), congenitally corrected transposition of the great arteries is often asymptomatic until adulthood.

A

Tetralogy of Fallot Because the surgical repair is usually performed during early childhood, the role of CT in diagnosing TOF is minimal. In postsurgical evaluation, the main purpose of CT is to visualize extracardiac complications, to depict the morphological characteristics of the main PA and its branches (to identify any obstruction, distortion after previous palliative shunt creation, or aneurysm), and to detect any right ventricular enlargement due to chronic volume overload in the presence of severe pulmonary regurgitation (Figs 85.56A and B).

Coarctation of the Aorta Congenital Heart Disease The most common type of coarctation seen in adults is postductal, where the narrowing is located just distal to the left subclavian artery. The aorta just distal to the coarctation is typically dilated and there is often dilatation of the left subclavian artery (Fig. 85.57). There is slightly higher incidence of associated bicuspid AVs in patients with Turner syndrome. Preoperatively, CT can easily establish the diagnosis of coarctation and provide additional information about collateral flow. Postoperatively, CT can be used to evaluate restenosis, patch dilatation, or patency of endo-stent depending on the type of treatment used.

B

Figs 85.55A and B: Corrected transposition. In congenitally corrected transposition, there is atrioventricular and ventriculoarterial discordance such that the left atrium (LA) is connected to right ventricle (RV), which is connected to the aorta. The right atrium (RA) is connected to left ventricle (LV) and is then connected to the pulmonary artery (PA). The circulation circuit in these patients is: systemic blood return morphological RA morphological LV pulmonary arteries. Oxygenated blood from lungs return via pulmonary veins morphological LA morphological R V aorta.


A

2063

B

Figs 85.56A and B: Tetralogy of Fallot (TOF) after palliation treatment. A 64-year-old female with prior Blalock–Taussig palliation for tetralogy of Fallot. Oblique coronal three-dimensional (3D) volume-rendered reconstruction demonstrating right ventricular (RV) hypertrophy, overriding aorta (AO): and subaortic ventricular septal defect (VSD; asterisk). 3D volume-rendered slab reconstruction illustrating the right ventricular outflow tract obstruction (arrow). (PA: Pulmonary artery).

Fig. 85.57: Coarctation of aorta. Volume-rendered sagittal oblique view of the thoracic aorta demonstrates focal narrowing of the descending aorta (circle) beyond the origin of the left subclavian artery (LSA). A few of the dilated collateral vessels are also seen in this image (arrows).

Fig. 85.58: Left ventricular assist device (LVAD). Typical location of inflow cannula (A) in left ventricle (LV) midcavity, pointed forward the mitral valve. The outflow cannula (B) is connected to the ascending aorta.

Left Ventricular Assist Device

worsening right heart failure, arrhythmias, hypotension, and hemolysis can be indicators of suboptimal LVAD function or related complications such as tamponade or aortic regurgitation. Accurate early recognition and management of these symptoms is important. CT has been used successfully to diagnose several common LVAD complications. CTA can delineate inflow and outflow cannula position, abnormal angulation, cannula thrombi, pericannula fluid collection, pericardial effusion, and driveline position (Figs 85.58 to 85.60). 3D reconstruction, a wide

There has been a steady increase in the number of continuous flow left ventricular assist devices (LVAD) implanted annually, since the Heartmate II LVAD was approved for bridge to transplant in 2008 and destination therapy in 2010. Given the persistent donor shortage and improvements in LVAD technology, patients are increasingly likely to undergo LVAD placement and remain on LVAD therapy for prolonged periods of time. Persistent left heart failure,

2064


A

B

Figs 85.59A and B: Outflow cannula thrombosis (B) in this patient with chronic heart failure and post-left ventricular assist device (LVAD) complication. This was also seen in the aortic root injection angiogram done in an attempt to remove the thrombus.

contains 15–35 mL of serous fluid.105 The normal pericardial thickness on CT/MR is < 2 mm.106,107 On CT, it is a linear isodense structure between the epicardial and pericardial fat.

Pericardial Duplication Cyst

Fig. 85.60: Left ventricular assist device (LVAD) obstruction. Abnormal position of inflow cannula (A), which is abutting the left ventricle (LV) lateral (arrow) wall causing obstruction. (RV: Right ventricle).

FOV, and reproducibility of measurements are advantages of CTA over echocardiographic techniques. In addition, gated and dynamic CTA can provide functional information, including right ventricular function and cardiac output.102–104

Pericardial Diseases Pericardium is a dual layer fibrous sac surrounding the heart with inner visceral layer adherent to the epicardium and the outer parietal layer. The potential space between these two layers is called the pericardial cavity that

These are congenital encapsulated cysts in close proximity to the pericardium that usually do not communicate with the parent cavity. The incidence is rare, about 1 in 100,000.108 They can occur anywhere around the heart, but the right cardiophrenic angle is the commonest site.109 On imaging, these are seen as round or elliptical, thin-walled cystic lesions with low-density fluid within (H.U. 0–10; Figs 85.45A and B). However, higher attenuation contents could be seen with infection or hemorrhage.

Pericardial Defect It is a rare anomaly with the spectrum ranging from a small defect to complete absence of the pericardium.110 It is commonly seen along the left side of the heart and may have associated congenital abnormalities such as ASD, PDA, or a bicuspid AV.111 The lack of visualization of normal pericardium is a direct sign. However, it is difficult to visualize the normal pericardium along the left side of the heart. The indirect signs include levorotation of the heart, and interposition of lung tissue between the aorta and main PA or between inferior border of heart and diaphragm. Excessive motion of the cardiac apex is seen on cine MR images.112 Complete


absence of pericardium is usually asymptomatic. Partial absence may cause complications such as herniation with entrapment of a cardiac chamber or structure.

2065

further assessment with clinical history, echocardiography, or cardiac MR is indicated.

Constrictive Pericarditis Pericardial Effusion Pericardial effusion may be transudate, exudates, or hemorrhage. The role of imaging is to determine its presence, pericardial thickening, and mediastinal or thoracic abnormalities to explain the cause. There are no specific criteria for distinguishing physiological versus pathological pericardial fluid. Visual evaluation and categorization as mild, moderate, or severe is routinely performed (Fig. 85.61). Pericardial thickness of > 4 mm is considered abnormal.113 Mediastinal lymphadenopathy or presence of thoracic malignancy may raise the suspicion for malignant effusion. Hemorrhagic effusions are seen in the setting of trauma, dissection, postsurgery, and will show CT attenuation value between 40 and 80 H.U. (Fig. 85.62).

Pericardial Calcification Calcification of pericardium is secondary to a prior insult. Postcardiac surgery, hemopericardium, exudative effusions such as tuberculous, postradiation are some of the common causes of pericardial calcifications (Fig. 85.63). Pericardial calcification may result in constrictive physiology and

Fig. 85.61: Pericardial effusion and tamponade. Large amount of pericardial effusion (stars) producing a mass effect leading to compression of right ventricle (RV) and dilation of inferior vena cava (IVC), hepatic veins, and coronary sinus (CS) (not shown), supports the presence of tamponade physiology. (LA: Left atrium; LV: Left ventricle; RA: Right atrium).

Thickening and fibrosis of pericardium from inflammatory conditions mentioned above can lead to constrictive pericarditis. Pericardial calcification may be seen in up to 50% of these cases.114 Physiologically, there is impaired diastolic filling of the ventricles that leads to equalization of right and left ventricular diastolic pressures.115 The patient may present with right heart failure. The treatment is surgical stripping of the pericardium. It is important to distinguish this from restrictive cardiomyopathy, since they may have the same physiology although the treatment is completely different. Flattening of the RV free wall and tubular configuration of ventricles are other features that may be seen.

Pericardial Tumors Primary pericardial tumors are extremely rare and metastases are far more common (see Fig. 85.43).116 Focal or generalized pericardial thickening, enhancement, nodularity, and hemorrhagic pericardial effusions are some of the features that may be seen on CT. The common primary malignancies that metastasize to the pericardium are lung, breast, melanoma, and lymphoma.117

Fig. 85.62: Hemopericardium. High attenuating fluid (45 H.U.) in pericardial space is suggestive of blood. The cause of hemopericardium in this patient was uremia.

2066


Fig. 85.63: Pericardial calcification. The pericardium is thickened measuring 4 mm and shows areas of spotty calcification (arrows). This patient did not have constrictive physiology.

Primary pericardial tumors include sarcoma (see Fig. 85.44), mesothelioma, and lymphoma. Lipoma is the most common benign tumor of the pericardium. Fibroma and teratoma may also occur in relation to the pericardium. Both lipoma and teratoma have a low malignant potential.

CONCLUSION MDCT has evolved rapidly over the last decade into a powerful cardiac imaging tool that allows the physician to visualize the coronary artery anatomy along with cardiac morphology and function in a single noninvasive study. Advances in technology now enable us to scan patients with higher heart rates, decreased radiation dose, and ability to overcome calcium artifacts. CTA compares well to catheter angiography in detecting stenosis and, in addition is superior in detecting regional wall-motion abnormalities. Myocardial perfusion information can be derived from rest and stress MDCT, although its wider practical application is limited at this time. CT-FFR is in early investigational state but could become a game changer once it can be performed easily and quickly.

REFERENCES 1. Chandrasekar B, Doucet S, Bilodeau L, et al. Complications of cardiac catheterization in the current era: a single-center experience. Catheter Cardiovasc Interv. 2001;52(3):289–95. 2. Lessick J, Mutlak D, Rispler S, et al. Comparison of multidetector computed tomography versus echocardiography for assessing regional left ventricular function. Am J Cardiol. 2005;96(7):1011–15.

3. Schlosser T, Pagonidis K, Herborn CU, et al. Assessment of left ventricular parameters using 16-MDCT and new software for endocardial and epicardial border delineation. AJR Am J Roentgenol. 2005;184(3):765–73. 4. Mahnken AH, Muhlenbruch G, Gunther RW, et al. coronary arteries and beyond. Eur Radiol. 2007;17(4):994–1008. PMID:17066290. 5. Dirksen MS, Bax JJ, de Roos A, et al. Usefulness of dynamic multislice computed tomography of left ventricular function in unstable angina pectoris and comparison with echocardiography. Am J Cardiol. 2002;90(10):1157–60. 6. Fischbach R, Juergens KU, Ozgun M, et al. Assessment of regional left ventricular function with multidetectorrow computed tomography versus magnetic resonance imaging. Eur Radiol. 2007;17(4):1009–17. 7. Mahnken AH, Spuentrup E, Niethammer M, et al. Quantitative and qualitative assessment of left ventricular volume with ECG-gated multislice spiral CT: value of different image reconstruction algorithms in comparison to MRI. Acta Radiol. 2003;44(6):604–11. PMID:14616204. 8. Salm LP, Schuijf JD, de Roos A, et al. Global and regional left ventricular function assessment with 16-detector row CT: comparison with echocardiography and cardiovascular magnetic resonance. Eur J Echocardiogr. 2006;7(4):308–14. 9. Kalra MK, Maher MM, Rizzo S, et al. Radiation exposure and projected risks with multidetector-row computed tomography scanning: clinical strategies and technologic developments for dose reduction. J Comput Assist Tomogr. 2004;28(Suppl 1):S46–9. PMID:15258493. 10. Hall EJ. Lessons we have learned from our children: cancer risks from diagnostic radiology. Pediatr Radiol. 2002;32(10):700–06. 11. Brenner DJ, Hall EJ. Computed tomography–an increasing source of radiation exposure. N Engl J Med. 2007; 357(22):2277–84. 12. Bischoff B, Hein F, Meyer T, et al. Impact of a reduced tube voltage on CT angiography and radiation dose: results of the PROTECTION I study. JACC Cardiovasc Imaging. 2009;2(8):940–6. 13. Hausleiter J, Meyer T, Hermann F, et al. Estimated radiation dose associated with cardiac CT angiography. JAMA. 2009;301(5):500–7. 14. Freeman A, Learner R, Eggleton S, et al. Marked reduction of effective radiation dose in patients undergoing CT coronary angiography using prospective ECG gating. Heart Lung Circ. 2011;20(8):512–16. 15. Achenbach S, Marwan M, Schepis T, et al. High-pitch spiral acquisition: a new scan mode for coronary CT angiography. J Cardiovasc Comput Tomogr. 2009;3(2):117–21. PMID:19332343. 16. Achenbach S, Marwan M, Ropers D, et al. Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogramtriggered high-pitch spiral acquisition. Eur Heart J. 2010;31(3):340–6. PMID:19897497. 17. Alkadhi H, Stolzmann P, Desbiolles L, et al. Low-dose, 128slice, dual-source CT coronary angiography: accuracy and radiation dose of the high-pitch and the step-and-shoot mode. Heart. 2010;96(12):933–8.


18. Flohr TG, Leng S, Yu L, et al. Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: image reconstruction and assessment of image quality. Med Phys. 2009;36(12):5641–53. 19. Hausleiter J, Bischoff B, Hein F, et al. Feasibility of dualsource cardiac CT angiography with high-pitch scan protocols. J Cardiovasc Comput Tomogr. 2009;3(4):236–42. 20. Taylor AJ, Cerqueira M, Hodgson JM, et al. ACCF/ S C C T / AC R / A H A / A S E / A S N C / NA S C I / S C A I / S C M R 2010 Appropriate Use Criteria for Cardiac Computed Tomography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. J Cardiovasc Comput Tomogr. 2010;4(6):407.e1–407.33. 21. Alegria JR, Herrmann J, Holmes DR et a.. Myocardial bridging. Eur Heart J. 2005;26(12):1159–68. 22. Johnson KM, Dennis JM, Dowe DA. Extracardiac findings on coronary CT angiograms: Limited versus complete image review. AJR Am J Roentgenol. 2010;195(1):143–8. 23. Vlahos I, Chung R, Nair A, et al. Dual-energy CT: vascular applications. AJR Am J Roentgenol. 2012;199(5 Suppl): S87–97. 24. Budoff MJ, Dowe D, Jollis JG, et al. Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial. J Am Coll Cardiol. 2008;52(21):1724–32. 25. Ehara M, Surmely JF, Kawai M, et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population: comparison with conventional invasive angiography. Circ J. 2006;70(5):564–71. 26. Meijboom WB, Meijs MF, Schuijf JD, et al. Diagnostic accuracy of 64-slice computed tomography coronary angiography: a prospective, multicenter, multivendor study. J Am Coll Cardiol. 2008;52(25):2135–44. 27. Miller JM, Rochitte CE, Dewey M, et al. Diagnostic performance of coronary angiography by 64-row CT. N Engl J Med. 2008;359(22):2324–36. 28. Mollet NR, Cademartiri F, van Mieghem CA, et al. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography. Circulation. 2005;112(15):2318–23. 29. Oncel D, Oncel G, Tastan A, et al. Detection of significant coronary artery stenosis with 64-section MDCT angiography. Eur J Radiol. 2007;62(3):394–405. 30. Raff GL, Gallagher MJ, O’Neill WW, et al. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. J Am Coll Cardiol. 2005;46(3):552–7.

2067

31. Ropers D, Rixe J, Anders K, et al. Usefulness of multidetector row spiral computed tomography with 64- x 0.6-mm collimation and 330-ms rotation for the noninvasive detection of significant coronary artery stenoses. Am J Cardiol. 2006;97(3):343–8. 32. Brodoefel H, Burgstahler C, Tsiflikas I, et al. Dualsource CT: effect of heart rate, heart rate variability, and calcification on image quality and diagnostic accuracy. Radiology. 2008;247(2):346–55. 33. Johnson TR, Nikolaou K, Wintersperger BJ, et al. Dualsource CT cardiac imaging: initial experience. Eur Radiol. 2006;16(7):1409–15. 34. Leber AW, Johnson T, Becker A, et al. Diagnostic accuracy of dual-source multi-slice CT-coronary angiography in patients with an intermediate pretest likelihood for coronary artery disease. Eur Heart J. 2007;28(19):2354–60. 35. Rixe J, Rolf A, Conradi G, et al. Detection of relevant coronary artery disease using dual-source computed tomography in a high probability patient series: comparison with invasive angiography. Circ J. 2009;73(2):316–22. 36. Ropers U, Ropers D, Pflederer T, et al. Influence of heart rate on the diagnostic accuracy of dual-source computed tomography coronary angiography. J Am Coll Cardiol. 2007;50(25):2393–8. 37. Tsiflikas I, Brodoefel H, Reimann AJ, et al. Coronary CT angiography with dual source computed tomography in 170 patients. Eur J Radiol. 2010;74(1):161–5. 38. Weustink AC, Meijboom WB, Mollet NR, et al. Reliable highspeed coronary computed tomography in symptomatic patients. J Am Coll Cardiol. 2007;50(8):786–94. 39. Voros S, Rinehart S, Qian Z, et al. Prospective validation of standardized, 3-dimensional, quantitative coronary computed tomographic plaque measurements using radiofrequency backscatter intravascular ultrasound as reference standard in intermediate coronary arterial lesions: results from the ATLANTA I study. JACC Cardiovasc Interv. 2011;4(2):198–208. 40. Leber AW, Becker A, Knez A, et al. Accuracy of 64-slice computed tomography to classify and quantify plaque volumes in the proximal coronary system: a comparative study using intravascular ultrasound. J Amer Coll Cardiol. 2006;47(3):672–7. PMID:16458154. 41. Naghavi M, Libby P, Falk E, et al. From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I. Circulation. 2003;108(14):1664–72. PMID:14530185. 42. Inoue F, Sato Y, Matsumoto N, et al. Evaluation of plaque texture by means of multislice computed tomography in patients with acute coronary syndrome and stable angina. Circ J. 2004;68(9):840–4. 43. Sun Z, Ng KH. Prospective versus retrospective ECG-gated multislice CT coronary angiography: a systematic review of radiation dose and diagnostic accuracy. Eur J Radiol. 2012;81(2):e94–100. PMID:21316887. 44. Varnava AM, Mills PG, Davies MJ. Relationship between coronary artery remodeling and plaque vulnerability. Circulation. 2002;105(8):939–43. 45. Reilly SD, Litovsky SH, Steinkampf MP, et al. Statins improve human coronary atherosclerotic plaque morphology. Tex Heart Inst J. 2008;35(2):99–103.

2068


46. Hulten EA, Carbonaro S, Petrillo SP, et al. Prognostic value of cardiac computed tomography angiography: a systematic review and meta-analysis. J Am Coll Cardiol. 2011;57(10):1237–47. 47. Abidov A, Gallagher MJ, Chinnaiyan KM, et al. Clinical effectiveness of coronary computed tomographic angiography in the triage of patients to cardiac catheterization and revascularization after inconclusive stress testing: results of a 2-year prospective trial. J Nucl Cardiol. 2009; 16(5):701–13. 48. Cademartiri F, Seitun S, Romano M, et al. Prognostic value of 64-slice coronary angiography in diabetes mellitus patients with known or suspected coronary artery disease compared with a nondiabetic population. La Radiologia Medica. 2008;113(5):627–43. PMID:18478189. 49. Carrigan TP, Nair D, Schoenhagen P, et al. Prognostic utility of 64-slice computed tomography in patients with suspected but no documented coronary artery disease. Eur Heart J. 2009;30(3):362–71. 50. Danciu SC, Herrera CJ, Stecy PJ, et al. Usefulness of multislice computed tomographic coronary angiography to identify patients with abnormal myocardial perfusion stress in whom diagnostic catheterization may be safely avoided. Am J Cardiol. 2007;100(11):1605–8. 51. Gilard M, Le Gal G, Cornily JC, et al. Midterm prognosis of patients with suspected coronary artery disease and normal multislice computed tomographic findings: a prospective management outcome study. Arch Intern Med. 2007;167(15):1686–9. 52. Gopal A, Nasir K, Ahmadi N, et al. Cardiac computed tomographic angiography in an outpatient setting: an analysis of clinical outcomes over a 40-month period. J Cardiovasc Comput Tomogr. 2009;3(2):90–5. 53. Lesser JR, Flygenring B, Knickelbine T, et al. Clinical utility of coronary CT angiography: coronary stenosis detection and prognosis in ambulatory patients. Catheter Cardiovasc Interv. 2007;69(1):64–72. 54. Matsumoto N, Sato Y, Yoda S, et al. Prognostic value of non-obstructive CT low-dense coronary artery plaques detected by multislice computed tomography. Circ J. 2007;71(12):1898–903. 55. Min JK, Shaw LJ, Devereux RB, et al. Prognostic value of multidetector coronary computed tomographic angiography for prediction of all-cause mortality. J Am Coll Cardiol. 2007;50(12):1161–70. 56. Shaw LJ, Berman DS, Hendel RC, et al. Prognosis by coronary computed tomographic angiography: matched comparison with myocardial perfusion single-photon emission computed tomography. J Cardiovasc Comput Tomogr. 2008;2(2):93–101. 57. Russo V, Zavalloni A, Bacchi Reggiani ML, et al. Incremental prognostic value of coronary CT angiography in patients with suspected coronary artery disease. Circ Cardiovasc Imaging. 2010;3(4):351–9. 58. van Werkhoven JM, Schuijf JD, Gaemperli O, et al. Incremental prognostic value of multi-slice computed tomography coronary angiography over coronary artery calcium scoring in patients with suspected coronary artery disease. Eur Heart J. 2009;30(21):2622–9.

59. Yamamuro M, Tadamura E, Kubo S, et al. Cardiac functional analysis with multi-detector row CT and segmental reconstruction algorithm: comparison with echocardiography, SPECT, and MR imaging. Radiology. 2005;234(2):381–90. 60. Bastarrika G, Ramos-Duran L, Rosenblum MA, et al. Adenosine-stress dynamic myocardial CT perfusion imaging: initial clinical experience. Invest Radiol. 2010; 45(6):306–13. 61. George RT, Arbab-Zadeh A, Miller JM, et al. Adenosine stress 64- and 256-row detector computed tomography angiography and perfusion imaging: a pilot study evaluating the transmural extent of perfusion abnormalities to predict atherosclerosis causing myocardial ischemia. Circ Cardiovasc Imaging. 2009;2(3):174–82. 62. George RT, Jerosch-Herold M, Silva C, et al. Quantification of myocardial perfusion using dynamic 64-detector computed tomography. Invest Radiol. 2007;42(12):815–22. 63. George RT, Silva C, Cordeiro MA, et al. Multidetector computed tomography myocardial perfusion imaging during adenosine stress. J Am Coll Cardiol. 2006;48(1): 153–60. 64. Ko BS, Cameron JD, Defrance T, et al. CT stress myocardial perfusion imaging using multidetector CT–A review. J Cardiovasc Comput Tomogr. 2011;5(6):345–56. 65. Ruzsics B, Surányi P, Kiss P, et al. Automated multidetector computed tomography evaluation of subacutely infarcted myocardium. J Cardiovasc Comput Tomogr. 2008;2(1): 26–32. 66. Rocha-Filho JA, Blankstein R, Shturman LD, et al. Incremental value of adenosine-induced stress myocardial perfusion imaging with dual-source CT at cardiac CT angiography. Radiology. 2010;254(2):410–19. 67. Blankstein R, Shturman LD, Rogers IS, et al. Adenosineinduced stress myocardial perfusion imaging using dualsource cardiac computed tomography. J Am Coll Cardiol. 2009;54(12):1072–84. 68. Lima JA. CORE320: Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320-row detector computed tomography: The CORE320 Multicenter, Multinational Study 2012. 69. Min JK, Leipsic J, Pencina MJ, et al. Diagnostic accuracy of fractional flow reserve from anatomic CT angiography. JAMA. 2012;308(12):1237–45. 70. Greenland P, LaBree L, Azen SP, et al. Coronary artery calcium score combined with Framingham score for risk prediction in asymptomatic individuals. JAMA. 2004; 291(2):210–15. 71. Agatston AS, Janowitz WR, Hildner FJ, et al. Quantification of coronary artery calcium using ultrafast computed tomography. J Am Coll Cardiol. 1990;15(4):827–32. 72. Callister TQ, Cooil B, Raya SP, et al. Coronary artery disease: improved reproducibility of calcium scoring with an electron-beam CT volumetric method. Radiology. 1998; 208(3):807–14. PMID:9722864. 73. Nasir K, Raggi P, Rumberger JA, et al. Coronary artery calcium volume scores on electron beam tomography in 12,936 asymptomatic adults. Am J Cardiol. 2004;93(9):1146– 9. PMID:15110208.


74. Greenland P, Bonow RO, Brundage BH, et al. ACCF/AHA 2007 clinical expert consensus document on coronary artery calcium scoring by computed tomography in global cardiovascular risk assessment and in evaluation of patients with chest pain: a report of the American College of Cardiology Foundation Clinical Expert Consensus Task Force (ACCF/AHA Writing Committee to Update the 2000 Expert Consensus Document on Electron Beam Computed Tomography) developed in collaboration with the Society of Atherosclerosis Imaging and Prevention and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol. 2007;49(3):378–402. 75. Pope JH, Aufderheide TP, Ruthazer R, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med. 2000;342(16):1163–70. 76. Swap CJ, Nagurney JT. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes. JAMA. 2005;294(20):2623–9. 77. Scheffel H, Alkadhi H, Plass A, et al. Accuracy of dualsource CT coronary angiography: First experience in a high pre-test probability population without heart rate control. Eur Radiol. 2006;16(12):2739–47. 78. Leschka S, Alkadhi H, Plass A, et al. Accuracy of MSCT coronary angiography with 64-slice technology: first experience. Eur Heart J. 2005;26(15):1482–7. 79. Hoffmann U, Nagurney JT, Moselewski F, et al. Coronary multidetector computed tomography in the assessment of patients with acute chest pain. Circulation. 2006;114(21): 2251–60. 80. Meijboom WB, van Mieghem CA, Mollet NR, et al. 64-slice computed tomography coronary angiography in patients with high, intermediate, or low pretest probability of significant coronary artery disease. J Am Coll Cardiol. 2007;50(15):1469–75. 81. Goldstein JA, Gallagher MJ, O’Neill WW, et al. A randomized controlled trial of multi-slice coronary computed tomography for evaluation of acute chest pain. J Am Coll Cardiol. 2007;49(8):863–71. 82. Laudon DA, Vukov LF, Breen JF, et al. Use of electron-beam computed tomography in the evaluation of chest pain patients in the emergency department. Ann Emerg Med. 1999;33(1):15–21. 83. Georgiou D, Budoff MJ, Kaufer E, et al. Screening patients with chest pain in the emergency department using electron beam tomography: a follow-up study. J Am Coll Cardiol. 2001;38(1):105–10. 84. McLaughlin VV, Balogh T, Rich S. Utility of electron beam computed tomography to stratify patients presenting to the emergency room with chest pain. Am J Cardiol. 1999;84(3):327–8, A8. 85. Hoffmann U, Truong QA, Schoenfeld DA, et al. ROMICAT-II Investigators. Coronary CT angiography versus standard evaluation in acute chest pain. N Engl J Med. 2012;367(4):299–308. 86. Litt HI, Gatsonis C, Snyder B, et al. CT angiography for safe discharge of patients with possible acute coronary syndromes. N Engl J Med. 2012;366(15):1393–403.

2069

87. Goldstein JA, Chinnaiyan KM, Abidov A, et al. CT-STAT Investigators. The CT-STAT (Coronary Computed Tomographic Angiography for Systematic Triage of Acute Chest Pain Patients to Treatment) trial. J Am Coll Cardiol. 2011;58(14):1414–22. 88. Chinnaiyan KM, Raff GL, Goraya T, et al. Coronary computed tomography angiography after stress testing: results from a multicenter, statewide registry, ACIC (Advanced Cardiovascular Imaging Consortium). J Am Coll Cardiol. 2012;59(7):688–95. 89. Chinnaiyan KM, Depetris AM, Al-Mallah M, et al. Rationale, design, and goals of the Advanced Cardiovascular Imaging Consortium (ACIC): A Blue Cross Blue Shield of Michigan collaborative quality improvement project. Am Heart J. 2012;163(3):346–53. 90. Hamon M, Lepage O, Malagutti P, et al. Diagnostic performance of 16- and 64-section spiral CT for coronary artery bypass graft assessment: meta-analysis. Radiology. 2008;247(3):679–86. 91. Ehara M, Kawai M, Surmely JF, et al. Diagnostic accuracy of coronary in-stent restenosis using 64-slice computed tomography: comparison with invasive coronary angiography. J Am Coll Cardiol. 2007;49(9):951–9. 92. Araoz PA, Mulvagh SL, Tazelaar HD, et al. CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation. Radiographics. 2000;20(5): 1303–19. 93. Sparrow PJ, Kurian JB, Jones TR, et al. MR imaging of cardiac tumors. Radiographics. 2005;25(5):1255–76. 94. Shah DC, Haïssaguerre M, Jaïs P. Toward a mechanismbased understanding of atrial fibrillation. J Cardiovasc Electrophysiol. 2001;12(5):600–1. 95. Achenbach S, Delgado V, Hausleiter J, et al. SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/ transcatheter aortic valve replacement (TAVR). J Cardiovasc Comput Tomogr. 2012;6(6):366–80. 96. Gilard M, Eltchaninoff H, Iung B, et al. FRANCE 2 Investigators. Registry of transcatheter aortic-valve implantation in high-risk patients. N Engl J Med. 2012; 366(18): 1705–15. 97. Kodali SK, Williams MR, Smith CR, et al. PARTNER Trial Investigators. Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med. 2012; 366(18):1686–95. 98. Sinning JM, Hammerstingl C, Vasa-Nicotera M, et al. Aortic regurgitation index defines severity of peri-prosthetic regurgitation and predicts outcome in patients after transcatheter aortic valve implantation. J Am Coll Cardiol. 2012;59(13):1134–41. 99. Brickner ME, Hillis LD, Lange RA. Congenital heart disease in adults. First of two parts. New Engl J Med. 2000;342(4):256–63. PMID:10648769. 100. Otsuka M, Itoh A, Haze K. Sinus venosus type of atrial septal defect with partial anomalous pulmonary venous return evaluated by multislice CT. Heart. 2004;90(8):901.

2070


101. Siegel MJ, Bhalla S, Gutierrez FR, et al. MDCT of postoperative anatomy and complications in adults with cyanotic heart disease. AJR Am J Roentgenol. 2005;184(1): 241–7. 102. Acharya D, Singh S, Tallaj JA, et al. Use of gated cardiac computed tomography angiography in the assessment of left ventricular assist device dysfunction. ASAIO J (American Society for Artificial Internal Organs: 1992). 2011;57(1):32–7. PMID:20966744. 103. Raman SV, Sahu A, Merchant AZ, et al. Noninvasive assessment of left ventricular assist devices with cardiovascular computed tomography and impact on management. J Heart Lung Transplant. 2010;29(1):79–85. 104. Raman SV, Tran T, Simonetti OP, et al. Dynamic computed tomography to determine cardiac output in patients with left ventricular assist devices. J Thorac Cardiovasc Surg. 2009;137(5):1213–17. 105. Little WC, Freeman GL. Pericardial disease. Circulation. 2006;113(12):1622–32. 106. Bull RK, Edwards PD, Dixon AK. CT dimensions of the normal pericardium. Br J Radiol. 1998;71(849):923–5. 107. Sechtem U, Tscholakoff D, Higgins CB. MRI of the abnormal pericardium. AJR Am J Roentgenol. 1986;147(2): 245–52. 108. Hynes JK, Tajik AJ, Osborn MJ, et al. Two-dimensional echocardiographic diagnosis of pericardial cyst. Mayo Clin Proc. 1983;58(1):60–3.

109. Wang ZJ, Reddy GP, Gotway MB, et al. CT and MR imaging of pericardial disease. Radiographics: a review publication of the Radiological Society of North America, Inc. 2003;23 Spec No:S167-80. PMID:14557510. 110. Nasser WK. Congenital diseases of the pericardium. Cardiovasc Clin. 1976;7(3):271–86. 111. M. LW. Pericardial Diseases. In: Libby P BR, Zipes D, Mann D, editors. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, PA: WB Saunders & Co; 2008. 112. Psychidis-Papakyritsis P, de Roos A, Kroft LJ. Functional MRI of congenital absence of the pericardium. AJR Am J Roentgenol. 2007;189(6):W312–14. 113. Gopalan D, Raj V, Hoey ET. Cardiac CT: non-coronary applications. Postgrad Med J. 2010;86(1013):165–73. 114. O’Leary SM, Williams PL, Williams MP, et al. Imaging the pericardium: appearances on ECG-gated 64-detector row cardiac computed tomography. Br J Radiol. 2010;83(987): 194–205. 115. Sengupta PP, Eleid MF, Khandheria BK. Constrictive pericarditis. Circ J. 2008;72(10):1555–62. 116. Syed IS, Feng D, Harris SR, et al. MR imaging of cardiac masses. Magn Reson Imaging Clin N Am. 2008;16(2): 137–64, vii. 117. Klatt EC, Heitz DR. Cardiac metastases. Cancer. 1990;65(6): 1456–9.

Index Page number followed by f and t indicate figure and table respectively.

A Abdominal aortic aneurysm, ultrasound stethoscope for screening of, 294– 295 Aberration, 81 Abiomed Impella, 1224f Abnormal mitral arcade, 1613–1614 Absorption, 56–57 ACC. See American College of Cardiology (ACC) Accessory mitral orifice, 1615 ACCF. See American College of Cardiology Foundation (ACCF) Accreditation Council of Graduate Medical Education (ACGME), 754 Acetylcholine (Ach), 450, 451–452, 451f, 455 Ach. See Acetylcholine (Ach) ACM. See Alcohol-induced cardiomyopathy (ACM) Acoustic energy safety, 111 Acoustic enhancement, 734, 734f Acoustic radiation force impulses (ARFI), 1995 Acoustic shadowing, 61, 62f, 733–734 Acquired heart diseases, in childhood, 1856–1864 aortic insufficiency, 1860f complications of, 1859 coronary ectasia and aneurysms, 1861–1863 Duke criteria for, 1857 echocardiographic findings, 1857– 1859 infective endocarditis, 1856–1857 infective endocarditis prophylaxis, 1859 Jones criteria for, 1859–1861 acute valvulitis, 1860 chronic RHD, 1860–1861 minor criteria, 1860 Kawasaki disease, 1861, 1862t mitral valve insufficiency, 1860f

overview, 1856 rheumatic heart disease, 1859 vegetations in, 1858–1859 location for, 1958 size and embolic risk, 1958–1959 ACS. See Acute coronary syndromes (ACS) AcuNav Diagnostic Ultrasound Catheter, 644, 645f. See also Intracardiac echocardiography (ICE) Acute aortic regurgitation, 1972 acute decompensation, 1974 acute regurgitation, 1974 aortic dissection, 1972 diastolic fluttering, 1974 infective endocarditis, 1972 left ventricular hypertrophy, 1974 post trauma, 1972t suprasternal notch, 1974 transthoracic views, 1974 ventricular septal defect, 1973f Acute chest pain, CT scan for, 2045–2047 Acute coronary syndromes (ACS) contrast echocardiography for, 443 echocardiography role in, 1292–1294 evaluation of, by CONTISCAN transducer, 226 Acute heart failure syndrome, 1986 Acute LV remodeling (ALVRM), 1325 Acute myocardial infarction, three dimensional speckle tracking and, 376t Acute pericarditis, 1436 Acute respiratory distress syndrome (ARDS), 1983, 1986 acute heart failure syndrome, 1986 chest X-ray, 1986 differential diagnosis, 1986 diffuse lung injury, 1986 lung ultrasound scan, 1986 sonographic pattern multiple diffuse B-lines, 1986, 1986f small subpleural consolidations, 1986, 1986f

spared areas, 1986 subclinical pulmonary edema, 1986 Acute rheumatic fever (ARF), 931 diagnosis of carditis in, 765–775 echo and Doppler studies, 768–770 echocardiography vs. clinical examination, 767–768 echo interrogation, 767, 769t–770t M-mode echo in, 770 myocarditis, 766 pericarditis, 766 pitfalls in Jones criteria, 766–767 regurgitation, 766 rheumatic vs. nonrheumatic regurgitation, 768 secondary prophylaxis, fidelity of, 775 two-dimensional echo, 770–772 overview, 765 physiological vs pathological regurgitation, 772–773 Vijaya's echo criteria, 771, 771t Adenosine stress test, 1333–1334 ADMA (asymmetrical dimethyl arginine), 454 Adriamycin-induced cardiomyopathy, 1397f Adult congenital heart disease (ACHD), 1791–1855 aortic root in, 1797, 1797f complex congenital heart defects, 1826–1848 echocardiography, key concepts of, 1793–1797 abdominal situs, 1795 assessment of shunts, 1795–1796 atrial situs solitus, 1794 atrioventricular relationship, 1795 position of apex, 1794 pregnancy and, 1796–1797 simplified segmental approach, 1793–1795 VA connections, 1795 indications for TEE, 1792t overview of, 1791–1793

I-II


simple congenital heart defects, 1798–1813 surgical terms in, 1794t terminology in, 1793t valvular disease, 1813–1826 Aging, effect of on HV Doppler, 303 on pulmonary venous flow, 329–330, 330f Air embolism, 1977 coronary arteries, 1977 hemodynamic instability, 1977 paradoxical emboli, 1977 postcardiac arrest, 1977 post multiple injuries, 1977 respiratory distress, 1977 Air microbubble contrast, 436 AIUM. See American Institute of Ultrasound in Medicine (AIUM) ALa. See Anterior leaflet angle (ALa) Alcohol-induced cardiomyopathy (ACM), 1397 Alcohol-induced necrosis, 1364f Alcohol septal ablation in HCM, 1362–1363 for hypertrophic obstructive cardiomyopathy, 571 Alfieri stitch, 539 Aliasing, 70, 137, 736. See also Artifacts Alveolar-interstitial syndrome, 1986 ALVRM. See Acute LV remodeling (ALVRM) Ambulatory echocardiography, 227–229, 229t American College of Cardiology (ACC), 750, 751–752, 757, 758 American College of Cardiology Foundation (ACCF), 758, 2045 “American correction,” 580 American Heart Association (AHA), 6, 758 American Institute of Ultrasound in Medicine (AIUM), 110 American Registry of Diagnostic Medical Sonography (ARDMS), 754 American Society of Anesthesiologists (ASA), 638 American Society of Echocardiography, 907 American Society of Echocardiography (ASE), 91, 132, 296, 516, 638, 753, 1115, 1323 A-mode echocardiography, 57, 58f Amplatzer PFO Occluder, 557 AmplatzerTM atrial septal occluder, 552–553, 554f

AmplatzerTM multifenestrated septal occluder, 553, 554f AmplatzerTM ventricular septal occluder, 558 Amplifier, 60 Amplitude Doppler. See Power Doppler Amptazer duct occlude II (ADO II) series, 1598 AMVL. See Anterior mitral valve leaflet (AMVL) Amyloid cardiomyopathy, 1398–1401, 1399f–1400f Amyloidosis, 1872–1874, 1873f–1874f velocity vector imaging in, 399 Analogue-to-digital converter, 67 Angiosarcomas, 1485–1486, 2055f Angle of insonation, 66 Annuloaortic ectasia, 974, 1695 Annuloplasty ring dehiscence, 608 “Annulus paradoxus,” 1446–1447 Anomalous coronary artery (ACA), 1763–1766 computed tomography for, 2047– 2049, 2047f in elderly, 1947f Anomalous origin of left main coronary artery from pulmonary artery (ALCAPA), 2048, 2048f Anomalous papillary muscle, 1354f Anomalous pulmonary venous drainage, 1676 Antegrade velocity of mitral inflow, 869 Anterior circulation, 665–668, 667f–669f Anterior leaflet angle (ALa), 1423 Anterior mitral valve leaflet (AMVL), 777 Anterior pericardial effusion, 170 Anthracycline exposure, 395 Aorta echocardiographic evaluation, 945–951 basic principles, 945 normal aortic size, 951 PLAX view, 945 PSAX view, 946 transesophageal echocardiography, 949–950, 950f, 951f transthoracic echocardiography, 945–949, 946f, 947f–949f and esophagus, 969 genetic syndromes affecting, 958–959 bicuspid aortopathy, 959 Marfan syndrome, 958–959 transesophageal imaging of, 967–982, 969f–970f

Index

acute aortic diseases, 976–982 aortic aneurysm, 974–976 aortography, 980 atherosclerotic disease, 971–974 celiac artery, 970 descending thoracic aorta, 970 human anatomic cross-section, 968f intramural hematoma, 978 left carotid and subclavian artery, 970, 971f magnetic resonance imaging and, 979 orientation, 968–970 real time 3D, 981 transgastric level, 969 Aortic abscess in native valve, 1045f transesophageal approach, 1053f Aortic aneurysms, 951–954, 1695–1696, 1797 anomalous origin of PA from ascending aorta, 1695–1696, 1696f echocardiographic evaluation of, 951–954, 952f–954f in elderly, 1934–1937 cystic medial degeneration and, 1936 etiology of, 1936 natural history of, 1937 with rupture, 1936f epidemiology of, 951 pathophysiology of, 951 pulmonary artery sling, 1696 transesophageal imaging of, 974–976 Aortic arch (AoA), 664–665, 665f, 666f, 1538f, 1795f abnormities, 1690–1692 cervical aortic arch, 1691 right aortic arch, 1690–1691 vascular rings, 1691 anomalies, 665 coarctation of aorta, 1692–1694 interruption of, 1694–1695, 1695t types of, 664–665, 665f Aortic arch anomalies, 1770–1773 aortic arch to pulmonary artery fistula, 1773 coarctation of aorta, 1770–1773 Aortic arch scanning protocol, carotid ultrasound, 676f Aortic atheroma, 959–961 appearance on TTE and TEE, 959, 960f grading, 961t

penetrating aortic ulceration, 961, 962f TEE characterization of, 960–961 Aortic atherosclerosis in elderly, 1921–1923, 1922f epiaortic ultrasonography in, 640–641, 641f in female, 1896f Aortic balloon valvuloplasty (ABV), 541 Aortic coarctation. See Coarctation of aorta (CoA) Aortic dissection, 954–958, 1974 aorta distal to left subclavian artery, 954 in ascending aorta, 954 diagnostic imaging, 1974 dissection, 1974 in elderly, 1937–1942, 1937f–1938f, 1941f acute coronary syndrome and, 1940 color Doppler flow in, 1942 descending thoracic aorta, 1942 perfusing lumen, 1942 rupture, 1938f–1940f epidemiology, 954 intramural hematoma, 957–958 TEE diagnosis of, 955–957 TTE evaluation, 955 Type A dissection, 954, 955–957 Type B dissection, 954 Aortic dissection, epiaortic ultrasonography for detection of, 641 Aortic insufficiency, 1860f and carotid ultrasound findings, 693 Aortic isthmus, 1538f Aortic leiomyosarcoma, 1489f–1490f Aortic lumen to pulmonary artery fistulas (APAF), 1773 Aortico-left ventricular tunnel, 1632 Aortico-right atrial tunnel, 1632 Aortico-right ventricle tunnel, 1632 Aortic override, 1633–1644 aortic arch, 1638–1639 aortopulmonary collaterals, 1639– 1640 coronary artery anomalies, 1640 patent arterial duct, 1639–1640 pulmonary arteries, 1637–1638, 1638f pulmonary stenosis, 1634–1637 tetralogy of Fallot with absent pulmonary valve, 1637, 1637f cardiac catheterization, indications for, 1641

echocardiographic measurements in, 1640–1641, 1640f postoperative evaluation of, 1641– 1644, 1642f ventricular septal defect, 1633–1634, 1633f–1634f Aortic regurgitation (AR), 806–812, 930–944, 1628–1630, 1630f in adults, 1824 aortic root dilatation, 1629–1630 aortic valve surgery, timing of, 941–942 cardiac MRI for, 2010–2011, 2011f causes of, 1628–1629, 1629t continuous wave Doppler, 810–811 signal of, 1279 3DE VCA measurement of, 280 diastolic fluttering of AML, 807–808 echocardiography exercise, 811 indications for, 807t role of transthoracic, 811 three-dimensional, 812 etiology of, 930–935 acute rheumatic fever, 931 aortic root and aortic annulus, diseases of, 935, 936f aortic valve cusps, diseases of, 930–935, 932f–935f Behçet's disease, 935 congenital cardiac defects and aorta abnormalities, 930–931 infective endocarditis, 931 systemic illnesses, 931 flow convergence, 809 follow-up in, 812 grading of, 810f left ventricle adaptation to, 941 left ventricular outflow abnormality, 1628–1629 pulsed wave Doppler, 810 regurgitant jet size, 808–809 severity, quantification of, 936–941 color Doppler methods, 936–939 continuous wave Doppler methods, 940–941, 941f mitral valve findings, 941 M-mode and 2D findings, 936, 937f parameters to grade, 937t pulsed wave Doppler methods, 939–940, 940f severity of, 808, 808t, 812, 1630 sinus of Valsalva aneurysm and, 1631 vena contracta imaging in, 938 Aortic root, 1621

I-III

ACHD and, 1797 anatomy of, 897 echocardiographic assessment of dimension, 1797 parasternal long-axis view of, 1797f Aortic sclerosis, echocardiography of, 899–900 Aortic stenosis, 802–806, 896–918 in adults, 1824 aortic jet velocity, 803–804 aortic valve Doppler examination, 904–912 appropriate examination, 904–905 mean and peak gradients, 906 pressure recovery, 912 valve area measurement, 906–907 aortic valve replacement for, 540–546 associated conditions, 806 asymptomatic patients with normal LV function, 912–923 cardiac MRI for, 2010, 2011f and carotid ultrasound findings, 693 with coexistent subvalvular stenosis, 903–904 critical neonatal, 1622–1623 3DE assessment of, 279 echocardiography in, 898–904 aortic measurements, 902–903 aortic sclerosis, 899–900 bicuspid aortic valve, 902 criteria for, 914t–916t indications and appropriateness for, 913, 914t M-mode, 898–899, 899f recommendations for, 802t stress, 805–806, 912–913 three-dimensional, 806, 900–902 two-dimensional, 899 in elderly, 1924–1934 aortic valve area, estimation of, 1926 2D echocardiography, 1924–1928, 1925f, 1927f 3D echocardiography, indications for, 1933t LFLG-AS with low EF, 1929f live/real time 3D TTE, 1930–1933 mild, 1921f PLFLG-AS with preserved EF, 1929–1930 prevalence and pathophysiology, 1924 severe, 1931f–1932f, 1933f transcatheter aortic valve replacement, 1934, 1935f ventricular response to, 1933–1934

I-IV


etiology of, 897–898 low-gradient, low stroke volume, severe, 908–911 aortic valve calcium score, 911 dobutamine infusion, 910 hypertension and, 911 low transvalvular gradients and, 913 mean transaortic pressure gradient, 804–805 normal aortic valve anatomy, 896–897 aortic root, 897 aortic valve, 896–897 oveview, 896 “pseudosevere group” of, 911 sclerosis to stenosis, 897–898 severity, estimation of, 803, 907–908, 907t definition of, 907, 907t methodological limitations in, 908, 908t, 909t pitfalls in estimation of, 908 technical errors in, 908 strain in evaluation of, 913 subvalvular, 1624–1626 supravalvular, 1626–1628 valve area, 805 valvular, 1618–1624 vs. hypoplastic left ventricle, 1623 Aortic trauma, and free rupture, 961–963 Aortic valve (AV), 582–584 anatomy of, 896–897 3DE assessment of, 278f, 279, 279f 3D echo of, 520–522, 520f intermittent opening of, 1242f short axis of, 1536f ventricular assist devices, 1231, 1231f Aortic valve, in adults, 1821–1826 aortic regurgitation, 1824 aortic stenosis, 1824 bicuspid, 1821–1824 cardiac catheterization, 1822–1823 echocardiography, 1821–1822 MRI/CT for, 1823 postoperative adult, 1824 stress testing, 1823–1824 subaortic stenosis, 1824–1825 supravalvular aortic stenosis, 1825–1826 Aortic valve annulus, 1621 Aortic valve area (AVA), 279, 1622 calculation of, 543, 585–586 Aortic valve calcium score:, 911 Aortic valve diseases, 802–816, 1318 aortic regurgitation, 806–812 continuous wave Doppler, 810–811

3D echocardiography, 812 diastolic fluttering of AML, 807–808 exercise echocardiography, 811 flow convergence, 809 follow-up in, 812 grading of, 810f pulsed wave Doppler, 810 regurgitant jet size, 808–809 role of TEE in, 811 severity of, 808, 808t, 812 aortic stenosis, 802–806 aortic jet velocity, 803–804 associated conditions, 806 3D echocardiography, 806 mean transaortic pressure gradient, 804–805 severity of, 803 stress echocardiography in, 805–806 valve area, 805 role of 3D TEE in operating room in, 582–588, 594f–600f stress echocardiography in, 1318 Aortic valve Doppler examination, 904–912 Aortic valve fibroelastoma, 1479f Aortic valve pseudoaneurysm, 1046f Aortic valve sclerosis, 1923f in elderly, 1923–1924, 1923f bicuspid, 1931f echocardiographic findings for, 1923–1924, 1930f normal hemodynamics in, 1924 pathophysiology of, 1923–1924 prevalence of, 1923–1924 systolic murmur, 1923 Aortic valve stenosis (AS) in adults, 919 calcific, 919 dobutamine stress echocardiography, response to, 921 invasive evaluation of, 923 invasive vs. noninvasive evaluation of, 922–924 SAVR role in, 926–927 severity grade, 919 three main entities of severe, 926t Aortocameral communications, 1632 aortico-left ventricular tunnel and, 1632 aortico-right atrial tunnel and, 1632 aortico-right ventricle tunnel and, 1632 Aortopulmonary window (APW), 1751, 1753f–1754f

Index

color flow mapping, 1603 types of, 1602 APAF. See Aortic lumen to pulmonary artery fistulas (APAF) Aperture 3D ultrasound imaging and, 80 and TEE image quality, 104, 106f Apical approach, of three-dimensional echocardiography, 244, 254f, 255f Apical hypertrophic cardiomyopathy, 1356 Apical window, TTE, 146, 148 five-chamber plane, 153–154, 153f, 154f, 154t Doppler imaging, 153–154, 154f, 154t technique, 153, 153f four-chamber plane, 148–153, 148f–153f, 149t chamber quantification, 150–151, 151f, 152f diastolic function assessment, 149–150, 150ff, 151f Doppler imaging, 149, 150f intracardiac shunts assessment, 153, 153f right heart assessment, 151–152, 152f technique, 148, 148f, 149t two-dimensional anatomic imaging, 148–149, 149f long-axis or three-chamber plane, 155, 156f two-chamber plane, 154–155, 154f, 155f chamber quantification, 154–155 Doppler imaging, 155 technique, 154, 154f two-dimensional anatomic imaging, 154, 154f, 155f Application specific integrated circuits (ASICs), 77, 77f, 78 ARDMS. See American Registry of Diagnostic Medical Sonography (ARDMS) Area under the curve (AUC), 452, 452f ARFI. See Acoustic radiation force impulses (ARFI) ARIC. See Atherosclerotic Risk in Communities (ARIC) study Arrhythmogenic right ventricular cardiomyopathy (ARVC), 1395– 1396 Arrhythmogenic right ventricular dysplasia (ARVD), 395–396, 1395– 1396, 1396f

Arterial–ventricular coupling, 1121–1122 Artifacts, 61, 732–749 acoustic shadowing and enhancement, 61, 62f, 733–734, 734f aliasing, 736 from assumptions made by ultrasound equipment software, 749t attenuation and enhancement, 61 categorization of, 733 double image, 736 3D ultrasound imaging and, 80–81 effects of tissues in ultrasonic beam, 732, 733f encountered in day-to-day clinical practice, 738f–748f identification and elimination of, 737 mirror image, 735–736 on pulmonary venous Doppler, 343–345, 344f–345f range ambiguity, 736 recognition and interpretation of, 732 reflection, 62, 62f reverberation, 62, 62f, 734–735, 735f side lobe artifacts, 62–63, 63f in three-dimensional echocardiography, 736–737 transesophageal echocardiography and, 107–110, 113–116, 114f ASD. See Atrial septal defect (ASD) ASE. See American Society of Echocardiography (ASE) Asymptomatic patients, with normal LV function, 912–923 Atherosclerosis, 959–961 grading, 961t transesophageal imaging of, 971–974 Atherosclerotic plaque, mild, 960f Atherosclerotic Risk in Communities (ARIC) study, 1948 Atresia, of left main coronary artery, 1689 Atretic coronary sinus ostium, 1683 Atrial and atrioventricular valve abnormalities, 1773–1776 cor triatriatum sinister, 1773–1775 Ebstein’s anomaly, 1775–1776 isolated mitral valve cleft, 1775 Atrial balloon septostomy, 531 Atrial ball valve thrombus, 845 Atrial fibrillation (AF), 1259–1260 computed tomography for, 2054–2057 myocardial sleeve of LA, 2056 paroxysms of, 2056 planning CT, 2057

radiofrequency catheter ablation, 2056 and HV Doppler, 309, 309f and PV Doppler, 333, 333f TD imaging in, 353 Atrial flutter, and PV Doppler, 333, 333f Atrial myxoma, 1468 Atrial septal defects (ASD), 1134, 1279, 1585–1591, 1734 in adults, 1799–1802, 1801t cardiac catheterization, 1802 closure of, 1802 contrast echocardiography, 1801– 1802 echocardiography, 1799 exercise testing, 1802 MRI/CTA for, 1802 postoperative adult in, 1802 transesophageal echocardiography, 1800–1801, 1800f types of, 1799–1800, 1799f atrial septum, evaluation of, 1590 basal long-axis or bicaval view, 1590–1591 basal short-axis view, 1590 four-chamber view, 1591 cardiac catheterization in, 1590 closure of Amplatzer ASD occluder, 557f ASD closure using intracardiac echocardiography, 559f ASD sizing ballon, 556f closure devices, 552–553, 555f 3D TEE diagnosis of ASD, 551, 553, 553f 3D TEE monitoring of, 554–555, 557f, 558f 3D TEE sizing of ASDs, 556f 3D TEE visualization of ASD rim, 557f ICE imaging during, 648, 650, 650f indications for, 551 secundum ASDs, 552, 554f computed tomography for, 2059, 2060f coronary sinus, 1586 degree of left-to-right shunt in, 1590 direction of shunt, 1588–1589 3D TEE for, 513 echocardiographic imaging in, 1586–1588 fossa ovalis, 1586 for percutaneous device closure, 1591 objectives, 1585 ostium primum, 1586 patent foramen ovale, 1585–1586

I-V

and PV Doppler, 342, 342f Qp/Qs ratios in, 1589–1590 secundum, 1734–1742 sinus venosus, 1586, 1742–1743 stepwise evaluation for, 1586t three-dimensional speckle tracking and, 376t types of, 1585–1586 in women, 1900–1901, 1900f–1901f Atrial septum, 1248, 1962 ablation,patients, 1962 abnormalities, 1962 frequent, 1963 atrial tumor, 1963 fossa ovalis region, 1962 lipomatous, 1963 obesity, patients, 1963 saline contrast study, 1962 septum primum, 1962 septum secundum, 1962 trans-septal puncture, 1962 Waterston’s groove, 1963 Atrioventricular and ventricoarterial discordance, 1664–1670 abnormalities of RVOT, 1669 associated defects, 1664 associated malformations, 1667–1669 tricuspid value abnormalities, 1667–1669, 1668f ventricular septal defect, 1667, 1668f coarctation of aorta, 1669 coronary artery anatomy in, 1664– 1667, 1665f–1666f four-chamber views, 1665–1666 PLAX view, 1667 segmental analysis, 1664–1665 subcostal sagittal view, 1666–1667 left ventricular outflow tract obstruction, 1669 Atrioventricular canal defect (AVCD), 1535, 1544f, 1546f Atrioventricular connection, echocardiography of, 1558t, 1577–1579, 1578f concordant, 1579 discordant, 1579 isomeric, 1580 and loop rule, 1580 uniatrial and biventricular connection, 1580 univentricular, 1579–1580 Atrioventricular dissociation and HV Doppler, 308, 308f and PV Doppler, 331–332, 332f

I-VI


Atrioventricular septal defects (AVSD), 1604–1610, 1746–1747 in adults, 1809–1810 echocardiography, 1809–1810 postoperative adult, 1810 AV valve regurgitation, 1610 with common valvular orifice, 1606–1610 complete, 1606–1610 complex, 1608 3D TTE for, 1746–1747 echocardiography in, features of, 1605t hemodynamic assessment of, 1610 LAVV regurgitation and, 1747 LVOT obstruction in, 1608, 1609t needs for evaluation of, 1607 overview, 1604 partial, 1604–1606, 1610 pulmonary stenosis and, 1610 right ventricular outflow tract obstruction in, 1608 types of, 1604–1610, 1747–1751 Atrium, identification of, 1576–1577 aorta-IVC and abdomen, 1577 atrial appendage, 1576 atrial septum, 1576 coronary sinus, 1577 venous drainage, 1576 Attenuation artifacts, 56, 61, 431–433, 432f, 433f Auenbrugger, Leopold, 4 Augmentation index (AIx), 465, 467, 467f Aureus Staphylococci, 1043 Autocorrelation detector, 71 AVCD. See Atrioventricular canal defect (AVCD) AV fistulas, 699–700 Axial resolution, 59, 59f, 733, 733f

B Balloon mitral valvotomy, in mitral stenosis, 839t, 842f complications of, 840–841 echocardiography in patients for, 838–840 evaluation of patient, 838–840, 839t mitral regurgitation in, 840–841 post, 841f, 843f, 844f Balloon valvuloplasty, monitoring of, by CONTISCAN transducer, 233, 233f, 234f Barlow’s syndrome, 1860

BART (blue away red toward), 64 Basilar artery, 668 Battery-powered ultrasound imagers, 291–292, 292f Beam width artifact, 733, 734f Behçet's disease, 935 Benign cardiac fibromas, 1480 Berlin Heart INCOR Assist Device, 1228 Bernoulli equation, limitations of, 1574 Biatrial myxoma, 1470f Bicuspid aortic valve (BAV), 898, 1766– 1770. See also Aortic valve in adults, 1821–1824 cardiac catheterization, 1822–1823 echocardiography, 1821–1822 MRI/CT for, 1823 postoperative adult, 1824 stress testing, 1823–1824 “aortopathy” or aortic enlargement in, 902 echocardiography of, 902 in female, 1913f–1914f M-mode echo for, 7, 7f progressive degenerative changes in, 902 Bicuspid aortopathy, 959 Bicycle stress echocardiography, 269 Bilateral superior vena cava (BLSVC), 1543f, 1683 Bioprosthetic aortic valve with anterior paravalvular aortic regurgitation, 1088f flow velocity across, 1091f with posterior mass, 1089f severe stenosis and, 1090f Bioprosthetic mitral valve transesophageal echocardiogram of, 1088f vegetations on leaflets, 1089f Bioprosthetic tricuspid valve with severe stenosis, 1091f struts and, 1085f transesophageal echocardiogram of, 1089f Bioprosthetic valves, 1081–1082 aortic, 1088f mitral, 1088f stented porcine, 1081t unstented porcine, 1082t Biplane method of discs, 1118–1119 Biplane transesophageal echo (TEE) probe, 100f Biventricular apical hypertrophy, 1554f Biventricular pacing, 234, 1378f–1379f

Index

Block matching, 275 Blood velocity, and Doppler signal, 66 Blooming, 433, 434f BLSVC. See Bilateral superior vena cava (BLSVC) Blunt chest trauma, 1969 assault, 1969 blunt objects, 1969 cardiac trauma, 1970t hemodynamic disturbances, 1970t hemodynamic instability, 1970t infarction, 1970t myocardial ischemia, 1970t intraoperative assessment, 1970t massive hemothorax, 1970 pericardial effusion, 1970t puncture injuries, 1970 thoracic aortic pathology, 1970t thoracic trauma, 1970t vehicle collisions, 1969 B-mode echocardiography, 57, 58f BNP. See Brain natriuretic peptide (BNP) Bolus infusions, 421 Bom, Nicolaas, 8 Bovine arch, 665, 666f Bovis Streptococci, 1043 Brachial/radial artery occlusion and release, 453 Bradykinin, 455 Brain natriuretic peptide (BNP), 295, 1422 British Society of Echocardiography, 750 Brockenbrough needle, 533 Budd-Chiari syndrome, 319

C Calcific aortic stenosis. See also Aortic stenosis 2D echocardiography in, 900 effective orifice area in, 900 geometric orifice area in, 900 Calcium channel blockers (CCB), 1073t Calcium-related factors, in cardiac motion, 1202 Cannon wave, 308, 308f Cannula flow velocities, 1248 Capacitance micro-machined ultrasound transducer (cMUT), 1992 Capacitive micromachined ultrasonic transducer (CMUT), 115f, 116, 116f Capillary blood volume (CBV), 421–422 Capillary wedge pressure (CWP), 1063 Carcinoid heart disease, 1006, 1407–1413, 1500

with carcinoid syndrome, 1408 cardiac involvement in, 1408 2D transthoracic echocardiography, 1007f echocardiographic features, 1409– 1413 endocardial deposits, 1409, 1410f–1412f left-sided valvular involvement, 1409, 1410f pulmonary valve cusps, 1409 tricuspid regurgitation, 1412 Carcinoid tumors, 1874–1875, 1876f Cardiac amyloidosis, 352, 373, 1261 Cardiac MRI for, 2008f Cardiac calcified amorphous tumor (CAT), 1512–1514 Cardiac catheterization in atrial septal defects, 1590 of bicuspid aortic valve in adults, 1822–1823 in CCTGA, 1841 in coarctation of aorta, 1829 double outlet right ventricle, 1845 in D-transposition of great arteries, 1838 echo gradients during, 1574, 1575f indications for, tetralogy of Fallot and, 1641 truncus arteriosus, 1844 univentricular hearts, 1847–1848 Cardiac computed tomography, 2023– 2070 advantages of, 2024 anomalous pulmonary venous connection, 2059 aorta congenital heart disease, coarctation of, 2062, 2063f atrial septal defect, 2059, 2060f cardiac function, 2042, 2043f CCTA, contraindications for, 2027 challenges for, 2024–2025 cardiac gating, 2024–2025 spatial resolution, 2024, 2024t temporal resolution, 2024, 2024t clinical indications for, 2044–2066 acute chest pain, 2045–2047 anomalous coronary artery, 2047– 2049, 2047f asymptomatic intermediate risk patient, 2049–2050 cardiac masses, 2051–2054 congenital heart disease, 2059–2063 coronary artery bypass graft, 2050, 2052f

coronary calcium scoring, 2044–2045, 2045f, 2046f coronary stent evaluation, 2050 left ventricular assist device, 2063– 2064 pericardial diseases, 2064–2066 pulmonary vein ablation, 2054–2057 re-do coronary artery bypass graft, 2049 constrictive pericarditis, 2065 contrast media and injection and, 2029t coronary calcium score protocol, 2028t FOV for, 2027 image analysis, 2032–2034 extracardiac findings in, 2033–2034, 2037f proper phase selection, 2033 image postprocessing, 2028–2032 curved multiplanar reformation, 2029 maximum-intensity projection, 2029, 2032f multiplanar reconstruction, 2029, 2301f transaxial images, 2028–2029 virtual endoscopy, 2030 volume rendering, 2030 major adverse cardiovascular events in, 2042 in myocardial perfusion, 2042–2043 overview, 2023–2024 patient preparation for, 2028t patient selection for, 2027 pericardial calcification, 2065, 2066f pericardial defects, 2064–2065 pericardial duplication cyst, 2064 pericardial effusion, 2065, 2065f pericardial tumors, 2065–2066 pitfalls and artifacts, 2034–2040 beam-hardening artifact, 2038, 2040f blooming artifacts, 2036–2038, 2039f cardiac motion artifact, 2034–2036 misregistration artifact, 2038f respiration motion artifact, 2036, 2039f plaque characterization, 2041–2042, 2041f preablation pulmonary valve mapping, 2028t radiation dose, 2025–2027 of common examinations, 2026t descriptors, 2026t methods to reduce, 2026–2027, 2027t

I-VII

stress myocardial imaging using, 2042–2043 technique, 2027, 2028t, 2029t tetralogy of fallot, 2062, 2063f transcatheter aortic valve replacement, 2029t, 2057–2059 transposition of great arteries, 2059–2062, 2061f congenitally corrected, 2062, 2062f Cardiac contusion, 1971 biochemical cardiac markers, 1971 echocardiogram, 1971 echo findings sum, 1971 electrocardiogram, 1971 myocardium, 1971 post trauma, 1972 Cardiac fibroma, 2054f Cardiac hemangiomas, 1482–1484 Cardiac hypertrophy, cardiac MRI in, 2006–2008 Cardiac imaging, 3–4. See also Echocardiography Cardiac implantable electronic devices (CIED), 1967 cardiac arrest, 1967 cardiac resynchronization therapy, 1967 echocardiography, 1967 infective endocarditis, 1967 heart disease, 1967 coronary artery disease, 1967 dilated cardiomyopathy, 1967 hypertrophic cardiomyopathy, 1967 lead extraction, 1967 preprocedural selection, 1967 symptomatic bradycardia, pacing, 1967 ventricular arrhythmias, 1967 Cardiac lipomas, 1481–1482, 1483f Cardiac magnetic resonance imaging, in ICM/NICM, 1427–1428 Cardiac masses, role of 3D TEE in operating room in, 617–627, 625f–634f Cardiac motion, 1176–1209 calcium-related factors in, 1202 clinical implications, 1201 definitions, 1183–1184 diastolic dysfunction, 1201–1202 dilated cardiomyopathy and, 1202–1203 heart function, basic, 1177–1180, 1177f–1180f MRI phase contrast velocity mapping of, 1179f

I-VIII


myocardial fiber organization, 1180f time frames of systole and diastole, 1177f–1178f during isovolumic contraction, 1185f myocyte factors in, 1202 of normal heart, 1185–1194 overview, 1176–1177 pacing factors in, 1203–1204 right heart failure and, 1204 right ventricle, 1198 rotation, 1183 state-of-the-art, 1180–1181 composite of, 1181–1183 HVMB model, 1181 muscle contraction, asynchronous, 1181 subendocardial muscle, 1198–1200, 1199f, 1200f torsion, 1183–1184 twisting, 1183 untwisting, 1183 mitral valve opening and, 1200–1201 torsion and, 1184–1185, 1200 ventricular septum, 1194–1198 ventricular structure, function of, 1177f–1178f Cardiac MRI (CMR), 381 cardiac amyloidosis, 2008f for cardiac hypertrophy, 2006–2008, 2007f cardiomyopathies, 2008 for left and right ventricle, 1998–1999, 1999f for left ventricular structure, 2000– 2004 LVNC, 2000–2002, 2001f, 2002f tissue characterization, 2002–2003, 2003t limitations of, 2017–2019 for mitral valve, 2012 for myocardial infarction, 2003–2004, 2004f for myocarditis and sarcoidosis, 2004–2006, 2005f, 2006f for normal variants and masses, 2016–2017 overview, 1998 pericardial disease, 2014–2016, 2015f of prosthetic valves, 2013–2014 strain assessment, 1999–2000, 2000f for valvular heart disease, 2009–2013 aortic regurgitation, 2010–2011, 2011f aortic stenosis, 2010, 2011f mitral regurgitation, 2012–2013 mitral stenosis, 2013

tricuspid regurgitation, 2013, 2014f velocity mapping, flow and shunt assessment, 2008–2009 viability assessment, 2003–2004 Cardiac myxoma, 1464–1475 Cardiac output (CO), 230, 231f, 1280, 1281 Cardiac Performance Analysis (CPA), 380 Cardiac plasmacytoma, 1490–1491, 1492f Cardiac resynchronization therapy (CRT), 233–234, 365, 1372 for heart failure, 369, 370f LBBB and, 1377 Cardiac rhabdomyoma, 1480–1481 Cardiac sarcoidosis, 3D speckle tracking and, 376t Cardiac shunts, 171 Cardiac situs, 1531f Cardiac tamponade, 1438–1440, 1970 blunt force, 1970 cardiac involvement, 1970 clinical presentation, 1970 and HV Doppler, 317, 317f left ventricular outflow tract diameter, 1974 myocardial contusion, 1970 pericardial effusion, 1970 pulsed wave Doppler, 1443f and PV Doppler, 341 right heart chamber collapses in, 1442t right ventricular wall, 1971t transmitral inflow velocities, 1970 transtricuspid velocities, 1970 tricuspid valve, 1971t Cardiac transplantation 2D STE and, 371 velocity vector imaging in, 399–400, 399f Cardiac tumors and masses, 1462–1523 atrial thrombus, 1504 cardiac thrombi, 1504 cardiac vegetation, 1506–1511 Chiari network, 1503 computed tomography for, 2051–2054 Coumadin ridge, 1503–1504 crista terminalis, 1503 differential diagnosis of, 1462–1463 echocardiographic assessment of, 1462–1464 3D TTE, 1464 full-volume acquisitions, 1463 limitation of, 1463 papillary fibroelastomas, 1463, 1476f–1477f Eustachian valve, 1503

Index

left ventricular thrombus, 1504–1506 malignant primary cardiac tumors, 1484–1511 angiosarcoma, 1485–1486 cardiac plasmacytoma, 1490–1491, 1492f fibrosarcomas, 1488 hydatid cyst, 1491, 1493f–1498f pericardial mesotheliomas, 1491 primary cardiac lymphoma, 1490 rhabdomyosarcoma, 1486–1488 sarcomas, 1484–1488 mesothelial/macrophage incidental cardiac excrescences, 1511– 1518 cardiac calcified amorphous tumor, 1512–1514 extracardiac masses, 1514, 1514f intracardiac hardware, 1514–1517 mitral annular calcification, 1512, 1512f moderator band, 1503 perivalvular abscess, 1511 primary benign cardiac tumors, 1464–1484 benign cardiac fibromas, 1480 cardiac hemangiomas, 1482–1484 cardiac lipomas, 1481–1482, 1483f cardiac myxoma, 1464–1475 cardiac rhabdomyoma, 1480–1481 papillary fibroelastomas, 1475–1480 secondary cardiac tumors, 1492–1500 carcinoid heart disease, 1500 malignant melanoma, 1500 thebesian valve, 1503 Cardiomyopathies. See also specific Cardiomyopathy diabetic, 1407, 1408 dilated. See Dilated cardiomyopathy (DCM) 2D STE and, 369–371 hemochromatosis, 1405 infectious, 1405–1407 HIV-associated cardiomyopathy, 1407 septic cardiomyopathy, 1405–1407 infiltrative, 1405 left ventricular noncompaction, 1384–1388 echocardiographic features of, 1385–1388, 1386f–1387f isolated, 1387f normal fetal ontogenesis, 1385 metabolic, 1407

in neuromuscular disorders, 396 peripartum, 1381–1384, 1381f–1384f primary, 1370 sarcoidosis, 1405, 1405f secondary, 1370 tachycardia-induced, 1388, 1395f Takotsubo cardiomyopathy, 1388, 1394f toxic, 1396–1397 adriamycin-induced cardiomyopathy, 1397f alcohol-induced cardiomyopathy, 1397 chemotherapy-induced cardiomyopathy, 1396–1397 two-dimensional echo, 1407 Cardiopulmonary bypass, and HV Doppler, 317, 318f Cardiopulmonary ultrasound, 1987 acute lung injury/ARDS, 1987 B-lines, 1987 evaluation, 1987 cardiogenic pulmonary congestion, 1987 echocardiography, 1987 echography, 1987 lung ultrasound scan, 1987 addition of, 1987 findings, 1987 helps in, 1987 pathological conditions, 1987 pulmonary fibrosis, 1987 three B-line scenarios, 1987, 1987t valvular heart disease, 1987 Cardiothoracic ratio, 1531f Cardiovascular Credentialing International (CCI), 754 Carditis, diagnosis of, 765–775 autopsy, 771f echo and Doppler studies, 768–770 echocardiography superiority of, 773–774 two-dimensional, 770–772 vs. clinical examination, 767–768 echo interrogation, 767, 769t–770t M-mode in, 770 myocarditis, 766 pericarditis, 766 pitfalls in Jones criteria, 766–767 regurgitation, 766 rheumatic vs. nonrheumatic regurgitation, 768 secondary prophylaxis, fidelity of, 775 Carotid artery, 673f Carotid bulb, 667, 668f

Carotid intima-media thickness (CIMT), 471, 676–677, 678f Carotid ultrasound examination. See Peripheral vascular ultrasound Carpentier, Alain, 580 Catheter-based LAA closure, 512 Catheter-based transcutaneous interventional procedures, 531–532 for device closure of cardiac shunts, 548 atrial septal defects (ASDs), 550–555 closure of PFOs, 555, 557 patent ductus arteriosus (PDA), 548–550 ventricular septal defects (VSDs), 557–559 fluoroscopy versus echocardiography in, 532 guidance of electrophysiology ablation procedures, 566, 568–569 miscellaneous procedures, 569 alcohol septal ablation, 571 left ventricular pseudoaneurysm closure, 569, 571, 571f right ventricular endomyocardial biopsy, 571 occlusion of left atrial appendage (LAA), 559–561 epicardial suturing of LAA, 563, 566 intracardiac device closure of LAA, 561, 563 transseptal puncture, 532–533 for valvular disease aortic stenosis, 540–546 mitral regurgitation, 538–540, 541f, 542f mitral stenosis, 533–537, 537f–539f paravalvular prosthetic leaks, closure of, 546–548, 550f, 551f CCAM. See Congenital cystic adenomatoid malformation (CCAM) CCB. See Calcium channel blockers (CCB) CCTA. See Coronary computed tomographic angiogram (CCTA) CCTGA. See Congenitally corrected transposition of great arteries (CCTGA) CDG. See Congenital disorders of glycosylation (CDG) CDH. See Congenital diaphragmatic hernia (CDH)

I-IX

Celiac artery, transesophageal imaging of, 970 Central processing unit (CPU), 60 Certified Cardiographic Technician (CCT), 754 Cervical aortic arch, 1691 Cervical arteries Doppler spectral waveforms, 674f CFR. See Coronary flow reserve (CFR) CFVR. See Coronary flow velocity reserve (CFVR) Chagas disease, 1875–1876, 1877f–1878f Chemotherapy cardiotoxicity, 2D STE and, 371–372 Chemotherapy-induced cardiomyopathy, 1396–1397 Chest trauma, 1969 cardiac injuries, 1969 penetrating injuries, 1969 perioperative indications, 1970t unintentional injury, 1969 Chiari network, 1503, 1776–1779 Chordae rupture, 1015 2D transthoracic echocardiography, 1012f, 1013f Chordal rupture, 857f Chordoma, in right ventricle, 1502f Chorionic villus biopsy (CVS), 1528 Christian Doppler’s principle, 26, 26f Chronic aortic stenosis, myocardial response to, 920 Chronic effusive pericarditis, 1437 Chronic irreversible verus dynamics, 1356–1358 Chronic ischemic heart disease echocardiography role in, 1298– 1301 ventricular function in, 1300–1301 diastolic function assessment, 1300–1301 systolic function assessment, 1300 Chronic kidney disease (CKD). See Renal disease Chronic obstructive pulmonary disease (COPD) and HV Doppler, 306, 307f squatting stress echocardiography in, 1323 Chronic thromboembolic pulmonary hypertension (CTEPH), 1073t, 1074 Circle of Willis, 669, 670f Circulation, 13 Circumferential strain, 362, 363f, 389 Cleft mitral leaflet, 1613

I-X


Clinical cardiac ultrasound, development of, 4–7 Clipping, 89 Clutter, 81 CoA. See Coarctation of aorta (CoA) Coaptation depth, 1423, 1424 Coarctation of aorta (CoA), 963, 964f, 1692–1694, 1770–1773 in adults, 1826–1829 cardiac catheterization, 1829 echocardiography, 1827–1828 MRI/CT for, 1828–1829 postoperative adult, 1829 surgical intervention for, 1829 treadmill stress testing, 1828 Doppler feature of, 1694 Coherent contrast imaging (CCI), 420 Collateral pathways, 669–671, 670f Color Doppler, 64, 113, 113ff, 114f Color Doppler imaging, three- dimensional echocardiography and, 248, 254–255, 266f Color Doppler ultrasound history of development of, 11 Color flow Doppler advantages and disadvantages of, 71 methodology, 71, 71f transthoracic echocardiogram, 137 Color maps, 71. See also Color flow Doppler Color processor, 71 Combined biventricular output (CVVO), 1529 Comet tail artifact, 734 Common atrium, 1747–1751, 1751f–1752f atrial septum and, 1800 Common carotid artery (CCA), 665 Complex congenital heart defects, 1826–1848 Complex congenital heart defects, in adults, 1826–1848 CCTGA, 1840–1842, 1842t cardiac catheterization, 1841 echocardiography, 1840–1841 exercise testing with stress echocardiography, 1841 magnetic resonance imaging, 1841 postoperative adult, 1842 surgery for, 1841–1842 coarctation of aorta, 1826–1829, 1828t cardiac catheterization, 1829 echocardiography, 1827 MRI/CT for, 1828–1829

postoperative adult, 1829 stress echocardiography, 1828 surgical intervention for, 1829 transesophageal echocardiography, 1827–1828 treadmill stress testing, 1828 double outlet right ventricle, 1824, 1825 D-transposition of great arteries, 1835–1840, 1837t cardiac catheterization, 1838 echocardiography, 1836–1838 MRI/CT for, 1838 postarterial switch repair, 1838 postatrial switch repair, 1836 reoperation for, 1838–1840 stress echocardiography, 1838 tetralogy of Fallot, 1829–1835, 1833t cardiac catheterization, 1834–1835 echocardiography, 1830–1832 MRI/CT for, 1835 postoperative adult, 1835 postoperative adult, surgery in, 1835 stress echocardiography, 1832–1834 truncus arteriosus, 1842–1844, 1843t cardiac catheterization, 1844 echocardiography, 1843 MRI/CT for, 1844 postoperative adult, 1844 surgery for, 1844 univentricular hearts, 1845–1848 cardiac catheterization, 1847–1848 echocardiography, 1846–1847 MRI /CTA for, 1847 transesophageal echocardiography, 1847 tricupsid atresia and post-fontan adult, 1845, 1846f Computational fluid mechanics, 67 Computed tomography angiogram (CTA) flow limiting disease, accuracy in, 2044 preoperative, 2049, 2050f retrospective gated, 2043f Congenital anomalies of coronary arteries, 1343–1344 of mitral valve, 1610–1615 individual mitral lesions, evaluation of, 1611–1615 mitral valve lesions, echocardiographic views, 1610–1611 types of, 1611t of tricuspid valve, 1616–1618

Index

congenitally unguarded tricuspid orifice, 1617–1618, 1617f Ebstein’s anomaly of, 1616–1617, 1616f tricuspid valve prolapse, 1617 Congenital aortic stenosis, 1766–1770 Congenital bicuspid aortic valve, 1619–1620, 1619f Congenital complete heart block (CCHB) fetal, 1529, 1545 Congenital cystic adenomatoid malformation (CCAM), 1530 Congenital diaphragmatic hernia (CDH), 1530 Congenital disorders of glycosylation (CDG), 1407 Congenital double orifice mitral valve, in mitral stenosis, 844–845 Congenital heart defects, simple, in adults, 1798–1813 shunt lesions, 1798–1813 atrial septal defects, 1799–1802, 1801t atrioventricular septal defect, 1809–1811 coronary artery fistula, 1812–1813 patent ductus arteriosus, 1805–1809 patent foramen ovale, 1798–1799 persistent left superior vena cava, 1810–1811 sinus of Valsalva aneurysm, 1811– 1812 ventricular septal defects, 1802–1805 Congenital heart disease (CHD), 1733– 1790, 1900–1902 aortic arch anomalies, 1770–1773 aortic arch to pulmonary artery fistula, 1773 coarctation of aorta, 1770–1773 aortopulmonary window, 1751 atrial and atrioventricular valve abnormalities, 1773–1776 cor triatriatum sinister, 1773–1775 Ebstein’s anomaly, 1775–1776 isolated mitral valve cleft, 1775 atrial septal defects, 1900–1901 Chiari network, 1776–1779 common atrium, 1747–1751, 1751f–1752f computed tomography for, 2059–2063 conotruncal anomalies, 1754–1766 anomalous coronary artery, 1763– 1766 tetralogy of fallot, 1763 transposition of great arteries, 1754–1763

dextrocardia, 1570–1575, 1570f Bernoulli equation, limitations of, 1574 color flow Doppler, 1570–1572 color flow information, 1572 continuous wave Doppler, 1572 Doppler gain and filter settings, inappropriate, 1571f, 1572f, 1573 Doppler scales, inappropriate, 1573, 1573f echo gradients during cardiac catheterization, 1574, 1575f nonimaging continuous wave Doppler probe, pitfalls of, 1573 poor echo windows, 1572 pulsed Doppler, 1572 signal alignment, inappropriate, 1573, 1574f transducer frequency, inappropriate, 1573 trivial lesions, pressure gradients across, 1574 double outlet right ventricle, 1779– 1783 left ventricular-RA communication, 1779–1782 right coronary artery fistula, 1782– 1783 echocardiography (imaging) of, 1563–1570 apical view, 1566–1567, 1566f conventional views of, 1563t high parasternal or ductal view, 1569, 1569f long-axis view, 1569, 1569f parasternal long-axis view, 1567, 1567f parasternal short-axis view, 1568– 1569, 1568f, 1569f pitfalls in, 1571–1572, 1571t short-axis view, 1570, 1570f subcostal window, 1563–1566, 1564f–1565f suprasternal views, 1569, 1569f, 1570f and HV Doppler, 317–318, 318f other abnormalities, 1776–1779 outflow tract obstruction, 1766–1770 congenital aortic stenosis/bicuspid aortic valve, 1766–1770 subaortic stenosis, 1770 overview, 1733 patent ductus arteriosus, 1751–1754, 1755f–1757f

patient preparation, 1562–1563, 1562f pulmonary hypertension, 1901–1902 RT 3DE approach to, 1170 sequential chamber analysis, principle of, 1575–1582 atrial arrangement, identification of, 1575–1577 atrioventricular connection, 1577– 1579 ventricular arterial connection, 1579–1582 shunt lesions/septal defects, 1733– 1747 atrial septal defects, 1734 atrioventricular septal defectsts 1746–1747 secundum ASD, 1734–1742 sinus venosus ASD, 1742–1743 unroofed coronary sinus, 1743 ventricular septal defects, 1743–1746 sinus of Valsalva aneurysm, 1784 hypoplastic left heart syndrome, 1784 right ventricular outflow obstruction and, 1784 Congenitally corrected transposition of great arteries (CCTGA), 1840–1842 cardiac catheterization, 1841 echocardiography, 1840–1841 exercise testing with stress echocardiography, 1841 magnetic resonance imaging, 1841 postoperative adult, 1842 surgery for, 1841–1842 velocity vector imaging in, 392 Congenitally corrected transposition of great vessels (CTGA), 1664, 1664f Congenitally stenotic tricuspid aortic valve, 1620 Congenitally unguarded tricuspid orifice, 1617–1618, 1617f Congenital mitral stenosis, 844 Congenital parachute mitral valve, 845, 846f Congenital subaortic membrane, 1359 Conotruncal anomalies, 1754–1766 anomalous coronary artery, 1763– 1766 tetralogy of fallot, 1763 transposition of great arteries, 1754–1763 Constrictive pericarditis (CP), 1444–1448 Doppler flow velocity records, 1446–1448, 1447f 3D TTE vs. 2D TTE, 1456–1457

I-XI

echocardiographic findings in, 1445t effusive, 1448f hepatic vein and, 1447f and HV Doppler, 315–317, 316f, 317f M-mode and 2D echo, 1444, 1445f, 1446f and PV Doppler, 340–341, 340f, 341f Continuity equation, 923 for aortic valve area, 906–907 for MVOA, 789 Continuous infusions, 421 Continuous wave Doppler, 63–64. See also Spectral Doppler disadvantage of, 68–69 methodology, 68–69, 69f Continuous-wave jet intensity, MR and, 869 CONTISCAN transducer, 224–237 use of, 224–225, 225f acute coronary syndromes, evaluation of, 226 ambulatory echocardiography, 227–229 balloon valvuloplasty, monitoring of, 233 cannulation of coronary sinus, monitoring of, 233–236 exercise echocardiography, 226–227 intraoperative monitoring, 236–237 noninvasive hemodynamic monitoring, 229–230 pericardiocentesis, monitoring of, 230–233 Contractile reserve, assessment of, 276 Contrast CMR (gadolinium), 2020 Contrast defect area (CDA), 423 Contrast defect length (CDL), 423–424 Contrast echocardiography, 416–436, 737, 1308. See also Myocardial contrast echocardiography (MCE) contrast administration bolus injection, 421 continuous infusion, 421 contrast agents, 416–417, 417f commercially available, 417, 418t idle, properties of, 417 safety of, 434–435, 435t ultrasound and, interaction between, 418–419, 419f use of, 428–431 contrast imaging, physics of, 417–418, 418f history of development of, 11–13 imaging modalities, 420, 420f

I-XII


intermittent/triggered imaging, 420–421 real time imaging, 420 indications for, 426 enhanced endocardial border delineation (EBD), 426, 426f left ventricular opacification (LVO), 426–427, 427f–429f myocardial perfusion, evaluation of, 427–428, 429f myocardial perfusion, principles of assessment of, 421–422, 422f contrast modality during MCE, 422–423 qualitative MCE, 423, 424f, 425f quantitative MCE, 424, 426 semiquantitative MCE, 423–424, 425f and problems, 431 attenuation artifacts, 431–433, 432f, 433f blooming, 433, 434f swirling, 433, 434f thoracic cage artifacts, 433–434, 434f saline, 435, 436f training in, 757 Contrast microbubbles, 416–417 Contrast score index, 441 COPD. See Chronic obstructive pulmonary disease (COPD) CoreValve, self-expandable, 541–542, 543 Coronary aneurysms, 1688–1689 atresia of left main coronary artery, 1689 Kawasaki disease, 1688–1689 Coronary anomaly, 1344f Coronary arteries, 1337–1347 anatomy and physiology, 1337 congenital abnormalities of, 1343– 1344 coronary flow reserve, 1340–1343 coronary ostia, 1338 coronary stenosis, 1338 distal coronary flow, 1340–1343 normal left main, 1339f overview, 1337 parasternal short-axis view for, 1569, 1569f proximal, 1338f, 1339f, 1341f, 1341t visualization of, 1337–1340 transesophageal echocardiography, 1338–1340 transthoracic echocardiography, 1337–1338 Coronary arteriovenous fistulas, 1688, 1689f

Coronary artery anomalies, 1684–1688 anomalous pulmonary origin of coronary artery, 1685–1687 of right coronary artery, 1687 tangential origin of coronary artery, 1687–1688 Coronary artery disease (CAD) ALVRM on squatting and, 1325 2D STE and, 367 evaluation of, 226 squatting SE vs. dobutamine SE for, 1325 squatting stress echocardiography in, 1323 three-dimensional vs. two dimensional in, 1332t velocity vector imaging in, 396–398 Coronary artery distribution, 1116f Coronary artery fistula, 2048–2049 in adults, 1812–1813 sequelae of, 2049 Coronary calcium scoringm, in computed tomography, 2044–2045, 2045f, 2046f Coronary computed tomography angiogram (CCTA), 2035f. See also Cardiac computed tomography contraindications for, 2027 coronary plaque, 2041–2042 diagnostic accuracy of, 2040–2041 flow limiting disease, accuracy in, 2044 in ICM/NICM, 1427 optimization of, 2029t optimization of anomalous, 2049t prognostic information from, 2042 protocol on 64 detector scanner, 2028t Coronary fistulas, 1343–1344 pediatric type, 1345f Coronary flow reserve (CFR), 1340–1343 conditions decreasing, 1342t impairment of, 1343 Coronary flow velocity reserve (CFVR), 446, 1337, 1341–1343, 1344 conditions impairing, 1342t noninvasive evaluation of, 1341–1342 normal, 1343f Coronary ostia, 1338 Coronary sinus defect in wall of, 1679–1680 partial or completely unroofed, 1683 Coronary sinus aneurysm/diverticulum, 1683

Index

Coronary sinus atrial septal defect, 1586 Coronary sinus cannulation, monitoring of, by CONTISCAN transducer, 233–236, 235f, 236f, 236t Coronary stenosis, 1338, 1340f cut-off values for, 1341t in elderly, 1943–1946, 1944f, 1946f in elderly female, 1897f–1899f Cor triatriatum sinister, 1773–1775 Cosine correction, 67f Coumadin ridge, 1503–1504 Crab view, 184, 185f Crista terminalis, 188, 1503 Critical neonatal aortic stenosis, 1622– 1623 Cropping, 241 Cropping, 3D echocardiography and, 269–270, 269f CRT. See Cardiac resynchronization therapy (CRT) CT-based fractional flow reserve (FFR CT), 2044 CT dose index volume (CTDIvol), 2026 CTEPH. See Chronic thromboembolic pulmonary hypertension (CTEPH) Curie, Pierre, 4 Curvilinear probe, 58, 58f CVS. See Chorionic villus biopsy (CVS) CVVO. See Combined biventricular output (CVVO) CWP. See Capillary wedge pressure (CWP) Cystic medial degeneration (CMD), 1936

D Dark blood imaging (spin echo), 2020 Data acquisition methods, 3D echocardiography cropping, 269–270, 269f 3DE color flow Doppler imaging, 269 image display, 269–270 multiplane mode, 268–269 multiple-beat 3DE imaging, 269 real time 3DE, 269 tomographic slices, 270, 270f 3D beamformer, 77–78 DDD pacing, for obstructive HCM, 1363 Debakey classification, 1974 aortic arch, 1974 ascending aorta, 1974 proximally, 1974 Deceleration time (DT), 313

Decompressive venous channels, 1684 Definity, 417, 418t. See also Contrast echocardiography Degenerative disease, 882f Degenerative mitral regurgitation, 863 Degenerative mitral valve stenosis, 844 DENSE. See Displacement encoding with stimulated echoes (DENSE) Depth, and frame rate, 59, 60f, 61 Dextro Transposition of great arteries (dTGA), 1528, 1549f, 1759f–1763f Dextrotransposition of great vessels, 6 DHF. See Diastolic heart failure (DHF) Diabetes, velocity vector imaging in, 398 Diabetic cardiomyopathy, 1407, 1408 Diastolic dysfunction cardiac motion and, 1201–1202 grade I, 1128 grade II, 1128 HCM and, 1356 identification of, 1126–1130 left ventricular hypertrophy patient with, 1125f Diastolic heart failure (DHF), 1124–1125 Diastolic pulmonary artery pressure (DPAP), 1065t, 1066, 1270–1272, 1272f DICOM format, 90, 95 Diet drug-induced valvulopathy, 1006 Digital Imaging and Communication (DICOM), 391 Dilated cardiomyopathy (DCM), 394–395, 445–446, 447f, 1202–1203, 1370– 1372, 1371f cardiac MRI for, 2008f chamber enlargement in, 1370 decompensated, 1374 etiology of, 1370, 1379–1397 familial, 1379–1381 ischemic cardiomyopathy, 1388– 1395, 1395f left ventricular contractility, 1370– 1372 mitral inflow filling pattern, 1376 mitral regurgitation, 1376 optimizing heart failure, echocardiography role in, 1376–1379 secondary findings in, 1372–1376 atrial fibrillation, 1376 cardiac dimensions, 1372–1374, 1373f Doppler echocardiography, 1375–1376 pericardial and pleural effusion, 1374 two-dimensional and M-mode findings, 1375, 1375f

systolic function in, 1371 ventricular remodeling, 1379 wall motion abnormalities in, 1371–1372 Dilated pulmonary valve, 1555f Dipyridamole stress test, 1334 Discrete subaortic membrane, 1771f–1772f Displacement encoding with stimulated echoes (DENSE), 1144 Distal coronary flow, 1340–1343 D-malposition of aorta, 1548f of great arteries, 1548f Dobutamine stress echocardiography (DSE), 274, 1307 Dobutamine stress test, 1331–1333 “Dominance,” 1181 Doppler, 1993 across-line Doppler shifts, 1993 beam-to-vessel angle, 1993 color Doppler, 1993 postacquisition, 1993 Doppler, Christian, 9 Doppler angiography. See Power Doppler Doppler equation, 65, 66 Doppler hemodynamics, with stress echocardiography, 1318–1319 aortic valve disease, 1318 dynamic pulmonary hypertension, 1318–1319, 1319f hypertrophic cardiomyopathy, 1318 latent diastolic dysfunction, 1318 mitral valve disease, 1318 Doppler principle, 349 Doppler shift, 65 Doppler spectral display, 67–68 Doppler tissue imaging. See Tissue Doppler Doppler ultrasound, 9–11, 63–64, 65–73 color Doppler, 64, 71 continuous wave Doppler, 63–64, 68–69 Doppler velocity determination, 72–73 history of development of, 9–11 information from, 73 instrumentation, 66–68 physical principles, 63 power Doppler, 71–72 pulsed wave Doppler, 63–64, 69–70 tissue Doppler, 64, 72 Doppler velocity determination, 72–73 errors in, 72 DORV. See Double outlet right ventricle (DORV)

I-XIII

Dose length product (DLP), 2026 Double-balloon catheter commissurotomy (CBC), 233 Double image artifacts, 736. See also Artifacts Double orifice mitral valve, 1614–1615, 1614f Double outlet right ventricle, 1779–1783, 1844–1845 cardiac catheterization, 1845 echocardiography, 1844 left ventricular-RA communication, 1779–1782 MRI/CT for, 1845 postoperative adult, 1845 right coronary artery fistula, 1782– 1783 stress echocardiography, 1845 surgery for, 1845 Double outlet right ventricle (DORV), 1580, 1644–1650 definition, 1645 echocardiography of, 1647 planning surgical strategy, role in, 1648–1650 great arteries and, 1645–1646 preoperative assessment of, checklist for, 1648t stenosis of pulmonary outflow, 1647–1648 aortic outflow obstruction, 1647 remote ventricular septal defect, 1648 ventricular septal defect, restriction of, 1647f, 1648 subaortic ventricular septal defect in, 1647 subpulmonary ventricular septal defect in, 1647 Taussig–Bing anomaly, 1647 ventricular septal defect, location of, 1645–1646 doubly committed, 1645 remote, 1645–1646, 1646f subaortic, 1645, 1645f subpulmonic, 1645, 1646f Doubly committed ventricular septal defect, TGA and, 1659 DPAP. See Diastolic pulmonary artery pressure (DPAP) 3DSTE. See Three-dimensional speckle tracking echocardiography (3DSTE) dTGA. See dextro Transposition of great arteries (dTGA) D-transposition of great arteries, 1835–1840

I-XIV


cardiac catheterization, 1838 echocardiography, 1836–1838 MRI/CT for, 1838 postarterial switch repair, 1838 postatrial switch repair, 1836 stress echocardiography, 1838 velocity vector imaging in, 392 Dual plane transesophageal echo (TEE) probe, 99–100, 100f Duchenne muscular dystrophy (DMD), 396 Ductal arch (DuAr), 1537f Ductus arteriosus, 548 Ductus venosus (DV), 1532f, 1538f Duplex scanning protocol, carotid ultrasound, 672f DuraHeart magnetically levitated centrifugal assist system, 1228 Dynamic pulmonary hypertension, stress echocardiography in, 1318–1319, 1319f Dysplasia of mitral valve, 1613 Dysplastic pulmonary valve, 1554f

E Early cardiac flow Doppler era, 24–49 color Doppler, development of, 37–38, 41f–44f diastology, 47–48 directional Doppler flowmetry, 29–30 Doppler presentation, controversy on, 30–31 flow concept, emergence of, 27–28 heart cavities, exploring of, 33, 34f intracardiac Doppler flow velocity traces changes, interpretation from, 33–34 mature flow Doppler era, 44, 46–47 nondirectional flow Doppler technique, 28–29 peripheral artery recordings, lessons from, 31, 33 preflow Doppler era invasive procedures in, 25 noninvasive procedures in, 25–26, 26f, 27f pulsed Doppler with 2D echocardiography, combination of, 36–37, 38f–40f transcutaneous approaches, return to, 34–36 Early gadolinium enhancement (EGE), 2020

EBCT. See Electron-beam computed tomography (EBCT) Ebstein’s anomaly, 986f, 1775–1776 associated with transposition of great vessels, 1777f 2D transesophageal echocardiography, 1025f–1028f of mitral valve, 1615 M-mode echocardiography, 986f RT 3DTTE for, 1777f–1779f transthoracic echocardiography three-dimensional, 1029f two-dimensional, 1024f–1025f tricuspid valve, 1616–1617, 1616f Echocardiography, 1957, 1969 ablation treatment, 1957 accessory pathways, 1957 angiography, 1958 coronary sinus contrast, 1958 arrhythmias, 1957 atrial fibrillation, 1957 atrioventricular, 1957 body surface area, 1958 cannulation, 1958 cardiac ablation, 1958 coronary sinus, 1957 Doppler in, 65–66. See also Doppler ultrasound echocardiogram, 1957 transthoracic, 1962f echocardiographic modalities, 1957 electrophysiologist, 1957 electrophysiology, 1957 history of, 3–19 clinical cardiac ultrasound, 4–7 color Doppler ultrasound, 11 contrast echocardiography, 11–13 2D echocardiography, 8–9 3D echocardiography, 14–18 Doppler ultrasound, 9–11 perspective on, 19 tissue Doppler and speckle tracking imaging, 14 transesophageal echocardiography, 13 ultrasound, 4 immediate invasive intervention, 1969 intracardiac echocardiography, 1957 midesophageal location, 1957 nodal re-entrant tachycardia, 1957 one-dimensional, 3f ostium, CS,CS-RA, 1958 parasternal, 1958f

Index

pediatric, 6 persistent left superior vena cava, 1958 progress in, 5f right atrium–right ventricle, 1958 risk stratification, 1969 superior vena cava, 1958f supraventricular tachycardia, 1957 supraventricular tachycardia, 1957 Thebesian valve, 1958 therapeutic, 1957 thoracic aorta, 1958f transesophageal echocardiogram, 1957 transthoracic, 1969 transthoracic echocardiogram, 1957 tricuspid valve, 1958 valve of Vieussens, 1958 Echocardiography, in elderly, 1921–1956 aortic aneurysm, 1934–1937 cystic medial degeneration and, 1936 etiology of, 1936 natural history of, 1937 with rupture, 1936f aortic atherosclerosis, 1921–1923, 1922f aortic dissection, 1937–1942, 1937f–1938f, 1941f acute coronary syndrome and, 1940 color Doppler flow in, 1942 descending thoracic aorta, 1942 perfusing lumen, 1942 rupture, 1938f–1940f aortic stenosis, 1924–1934 aortic valve area, estimation of, 1926 2D echocardiography, 1924–1928, 1925f, 1927f LFLG-AS with low EF, 1929f live/real time 3D TTE, 1930–1933 mild, 1921f PLFLG-AS with preserved EF, 1929–1930 prevalence and pathophysiology, 1924 severe, 1931f–1932f transcatheter aortic valve replacement, 1934, 1935f ventricular response to, 1933–1934 aortic valve sclerosis, 1923–1924, 1923f bicuspid, 1931f echocardiographic findings for, 1923–1924, 1930f normal hemodynamics in, 1924

pathophysiology of, 1923–1924 prevalence of, 1923–1924 systolic murmur, 1923 coronary stenosis, 1943–1946, 1944f, 1946f left ventricular mass, 1942–1943 mitral annular calcification, 1946– 1948 overview, 1921 penetrating aortic ulcer, 1921–1923 prosthetic valves, 1948–1949, 1949f Echocardiography, in women, 1886–1920 breast implant, 1887f congenital heart disease, 1900–1902 atrial septal defects, 1900–1901, 1900f–1901f pulmonary hypertension, 1901–1092 echocardiographic measurements vs. technical considerations, 1886– 1888 ischemic heart disease, 1889–1893 overview, 1886 polycystic ovarian syndrome, 1899 stress echocardiography, 1894–1899 structural heart disease, 1888–1889 mitral valve calcification, 1889, 1895f mitral valve prolapse, 1888, 1888f–1889f mitral valve stenosis, 1888–1889 Takotsubo cardiomyopathy, 1899– 1900 Echocardiography training, 750–760. See also Training, in echocardiography Echocardiography transducer, 55 Echo-clear space, 1440f Echo-guided pericardiocentesis, 1443– 1444 EchoPAC, 385 ECMO circuit. See Extracorporeal membrane oxygenator (ECMO) circuit Edge-to-edge repair, 539 Edler, Inge, 4–5 Edwards Sapien Valve, 2057 Effective orifice area (EOA) in calcific aortic stenosis, 900 patient prosthetic mismatch and, 1091–1092 of prosthetic valves, 1084–1087 Effective regurgitant orifice area (EROA), 518–519, 992, 1038 Effusive-constrictive pericarditis, 1448 Eisenmenger syndrome, 1597f Ejection fraction postamyocardial infarction, 1165t

Elastography, 1994, 1995 acoustic radiation force impulses, 1995 attraction of, 1995 breast malignancies, 1995 human tissue, 1994 mechanical properties, 1994 shear wave, 1995, 1995f advantage, 1995 strain elastography, 1995 tissues elastic properties two ways to image, 1995 tissue stiffness, 1995 Electric safety, TEE probe equipment and, 110–111, 111f, 111t Electromagnetic compatibility (EMC), 110 Electromagnetic interference (EMI), 112 Electron-beam computed tomography (EBCT), 2023 in ICM/NICM, 1427 Emergency department setting, MDCT in, 2045–2047 EMF. See Endomyocardial fibrosis (EMF) End-diastolic volume (EDV), 1156–1157 Endocardial border delineation (EBD), 421, 426 Endocardial cushion defect, 1535 Endocardial trabecular contouring algorithms, 1156–1157 Endocarditis pacemaker associated, 1214 of prosthetic valves, 1099–1100 Endocarditis prophylaxis, HCM and, 1363–1364 Endomyocardial fibrosis (EMF), 1402– 1404 Endothelial cells, 449–450, 449f dysfunction, 451. See also Endothelial dysfunction function of, 450, 450ff, 451t Endothelial dysfunction, 449–474. See also Flow-mediated dilatation (FMD) assessment of, methods for, 455–457, 456f, 456t and carotid intimal medial thickness, 471, 474f concept of FMD case studies on, 459–462 limitations of, 458–459, 663 conduit arteries, ultrasound imaging of, 456 cuff inflation pressure, 457 duration of occlusion, 457

I-XV

measurement of flow-mediated dilatation, 457, 457f proximal and distal occlusions, 456–457 quantification of shear stress, 457 technique of FMD in brachial artery, 458t factors affecting, 451, 451t future directions, 471, 474 NO release and, 455, 455f other methods for endothelial function assessment, 465 laser Doppler flowmetry, 469–470 low flow-mediated vasoconstriction, 470–471, 470f–474f peripheral arterial tonometry, 467–469, 468f, 469f pulse wave velocity analysis, 466–467, 466f, 467f shear stress and flow-mediated dilatation, 452–454, 452f shear stress and FMD response, analysis of, 457–458, 457f vasoactive molecules in vasoregulation, 454 endothelins, 454 endothelium-dependent hyperpolarizing factor, 454 nitric oxide, 454 prostacyclin, 454 Endothelial progenitor cells (EPCs), 450, 450f Endothelin (ET), 454 Endothelium-dependent hyperpolarizing factor (EDHF), 454 Endovascular Valve Edge-to-Edge Repair Study (EVEREST II) trial, 539 End-stage renal disease (ESRD), 1871– 1872, 1872f End-systolic volume index (ESVI), 180, 1379 ICM/NICM and, 1421–1422 Energy Doppler. See Power Doppler Enhancement, 61 eNOS (type-III NO-synthase), 454 EOA. See Effective orifice area (EOA) Epiaortic ultrasonography (EAU), 638–641 in aortic pathology aortic atherosclerosis, 640–641, 641f aortic dissection, 641 epiaortic probe and preparation, 638–639, 639f, 640f imaging views/planes, 639–640, 640f indications for, 638 three-dimensional, 641

I-XVI


Epicardial fat pad, 1518f E-point septal separation (EPSS), 169, 1117, 1375, 1375f EPSS. See E-point septal separation (EPSS) EROA. See Effective regurgitant orifice area (EROA) Esophagus, 967 ESVI. See End-systolic volume index (ESVI) Eulerian strain, 389 European Association of Cardiovascular Imaging (EACI), 91, 750, 751, 757, 758 European Association of Echocardiography (EAE), 132, 296, 907 European Society of Cardiology (ESC), 751 European Union (EU), 110 Eustachian valve, 1503 EvaHeart left ventricular system, 1228– 1129, 1228–1229 Exercise echocardiography, 226–227, 227f, 228f, 1307 External carotid artery (ECA), 665–666 Extracardiac masses, 1514, 1514f Extracorporeal membrane oxygenator (ECMO) circuit, 1127 Extravascular lung water (EVLW), 1982

F Fabry disease, 352, 1401–1402, 1401f False lumen (FL), 1977f FAPS. See French Aortic Plaque in Stroke (FAPS) study Fast Fourier transform (FFT), 67, 113 Fat pad, 170 Fatty infiltration of liver, 318 FDA 510 (K) Track 3 regulations, 111 Feigenbaum, Harvey, 6 Feinstein, Steve, 13 Fetal bradycardia, 1545 Fetal cardiac function, assessment of, by velocity vector imaging, 390–391 Fetal cardiac imaging, 1527–1560 congenital heart disease, family history of, 1529 fetal bradycardia, 1545 fetal cardiac evaluation, indications for, 1528 fetal cardiology, scope of, 1527–1528 fetal echocardiography, indications for, 1529

fetal heart disease, 1529–1530 congenital cystic adenomatoid malformation, 1530 congenital diaphragmatic hernia, 1530 sacrococcygeal teratoma, 1530 twin reverse arterial perfusion, 1530 twin–twin transfusion syndrome, 1529–1530 fundamentals of, 1530–1531 caval long-axis view, 1541 core and cord Dopplers, 1542 ductal and aortic arch views, 1541 fetal cardiac function, 1541–1542 fetal ultrasound, safety of, 1546–1547 four-chamber view, 1531–1541 rhythm assessment, 1542–1545 short-axis views, 1540–1541 three-dimensional imaging, 1549– 1553 ventricular long-axis view, 1541 overview, 1527–1560 physiology, 1528–1529 prenatal counseling in, 1528 reasons and associations for, 1529– 1530 Fetal echocardiography, in women, 1906–1919, 1906f–1909f Fetal heart abnormality, 1529 Fetal heart disease, fetal imaging, 1529–1530 congenital cystic adenomatoid malformation, 1530 congenital diaphragmatic hernia, 1530 sacrococcygeal teratoma, 1530 twin reverse arterial perfusion, 1530 twin–twin transfusion syndrome, 1529–1530 FFT analyzer, 67 Fibrinous adhesions, 1456–1457 Fibroma, 2051 Fibromuscular collar, 1625 Fibrosarcomas, 1488 First pass imaging (perfusion), 2020 Fixed anatomical obstruction, TGA and, 1660–1661 Fixed subaortic obstruction, 1624–1625 Flail tricuspid valve, 1007–1029 3d transthoracic echocardiography, 1012f in male with dyspnea, 1012f Flial posterior mitral valve leaflet, 853f Flow convergence method, MR severity and, 870–871

Index

Flow image, 71 Flow-mediated dilatation (FMD), 452–454, 452f–454f. See also Endothelial dysfunction clinical utility of, 465, 466t factors affecting ACE-inhibitors, 465 age and sex, 463 coronary risk factors, 463–464 diet, antioxidants, and supplements, 465 exercise, 465, 465f hyperglycemia, 464 infections, 465 smoking, 464, 464f sympathetic over activity, 465 unstable angina, 464–465, 465f weight loss, 465 FMD response, 452 Focus, and TEE image quality, 106, 106f Fontan procedure, and HV Doppler, 318, 318f Food and Drug Administration (FDA), 13, 110 Fossa ovalis anatomy of, 533, 535f 2D transesophageal examination, 988f Fossa ovalis atrial septal defect, 1586 for percutaneous device closure, 1591 Four-chamber asymmetry, 1548f Fourier, Joseph, 68 Fractional area change (FAC), 1166 Frame, 59 Frame rate, 59 depth and, 59, 60f image line density and, 59 sector angle and, 59, 60f Framingham Heart Study, 1161 French Aortic Plaque in Stroke (FAPS) study, 1921 Frequency, 55 in clinical use, 57 and TEE image quality, 104–105, 105f Fully sampled matrix-array transducers, 77, 268 Functional mitral regurgitation (FMR), 1372 DCM and, 1376, 1376f Fundamental imaging, 57 apical four-chamber view, 57f

G Gall stones, 220 Gating, 80

Gelatin-encapsulated nitrogen bubbles, 13 Gender,effect of, on HV Doppler, 303 Geometric orifice area (GOA), 900 Gerbode defect, 1603, 1603f, 1604f Geroulakos classification, of ultrasonic plaque, 678–679, 681f Ghost image, 61 Global circumferential peak systolic strain (GCS), 1728 Global circumferential strain (GCS), 91–92 Global longitudinal peak systolic strain (GLS), 1728 Global longitudinal strain (GLS), 91, 91f, 273, 1165 Global radial peak systolic strain (GRS), 1728 Global strain, 712–714, 712f–715f GLS. See Global longitudinal strain (GLS) “Goose neck” deformity, 1746 Gore-Helex atrial septal occluder, 553, 554f Gorlin equation, 923 Great vessels, identification of, 1579–1580 apical view, 1579 connection of, 1579–1580 PLAX view, 1579 GSPECT. See 99mTc-sestamibi gated single-photon computed emission tomography (GSPECT)

H Haemophylus influenzae, 1043 Hand-carried ultrasound device (HCD), 752 Harmonic imaging, 57 apical four-chamber view, 57f HeartAssist system, 1228 Heart chamber segmentation algorithms, 706–707, 707f Heart defects, in fetus, 1527–1528 Heart failure with preserved ejection fraction (HFnlEF), 1122 HeartMate II, 694, 1228 HeartWare ventricular system, 1224f, 1228 Heating safety, TEE probe equipment and, 111 Hemangioma involving mitral valve, 1485f left atrial, 1487f right ventricular, 1486f

Hematoma, 1517f after femoral artery access, 696, 697f Hemochromatosis, 1405 Hemodynamometer, 67 Hepatic veins (Hep V), 1532f anatomy of, 299–300, 300f versus biliary ducts, 305, 305f blood flow in, 300, 301f aging and, 303 Doppler V wave, 300, 302f exercise and, 303 factors affecting, 302–303, 303f gender and, 303 HV Doppler measurements, 302, 302f normal, 300, 301f physiology of, 300–302, 301f, 302f pregnancy and, 303 respiration and, 302–303, 303f two components of systolic flow, 300, 301f challenge to use of HV Doppler, 319–321, 320f disease states, and HV flow pattern, 305 atrial fibrillation, 309, 309f atrioventricular dissociation, 308, 308f cardiac tamponade, 317, 317f cardiopulmonary bypass, 317, 318f chronic obstructive lung disease, 306, 307f congenital heart disease, 317–318, 318f constrictive pericarditis, 315–317, 316f, 317f liver disease, 318–319, 319f premature ventricular contractions, 309, 309f prolonged PR interval, 308, 308f pulmonary hypertension, 311, 313, 313f restrictive cardiomyopathy, 315, 315f right ventricular diastolic dysfunction, 313–315, 315f right ventricular end-diastolic pressure, assessment of, 309–310, 310f right ventricular systolic dysfunction, 313, 314f short PR interval, 307, 308f sinus bradycardia, 306, 307f sinus tachycardia, 306, 307f tricuspid regurgitation, 310–311, 311f, 312f

I-XVII

tricuspid stenosis, 311, 312f heterotaxy syndrome and, 1706 HV Doppler flow patterns, schematic drawing of, 321f imaging of, 299–302 pulse Doppler across, 1539f spectral Doppler of, 319–321 versus superior vena cava, Doppler pattern of, 304, 304f transesophageal echocardiography, 305 transthoracic echocardiography, 304, 305f visualization and recording of HV Doppler, technical considerations in, 305, 305f, 306t Hepatic vein systolic filling fraction (HVFF), 1268 Hertz, Hellmuth, 4–5 Heterotaxy syndrome, 1704–1709 anatomy, 1704 cardiac and extracardiac anomalies in, 1705t initial echocardiogram of, 1704–1709 abdominal situs and cardiac position, 1704–1705 aortic arch and branches, 1709 atria and appendages, 1707 atrial septum, 1707 atrioventricular junction, 1707–1708 branch pulmonary arteries, 1708– 1709 pulmonary blood flow, sources of, 1708–1709 venoatrial connections, 1705–1707 ventricles and ventricular septum, 1708 ventriculoarterial connections, 1708 overview, 1704 venoatrial connections in, 1706t Hewlett Packard SONOS 5500, 227 HFnlEF. See Heart failure with preserved ejection fraction (HFnlEF) High-flow, high-gradient aortic stenosis, 920. See also Aortic stenosis Highly focused ultrasound (HIFU), 1996 High MI imaging, 420–421 High-pass filtering, 66–67 High pulse repetition frequency (HPRF), 64 HIV-associated cardiomyopathy, 1407 HLHS. See Hypoplastic left heart syndrome (HLHS) HOCM. See Hypertrophic obstructive cardiomyopathy (HOCM) Hodgkin lymphoma, 1491

I-XVIII


Homograft aortic prosthesis, 1100f Human hearing, 55 HVFF. See Hepatic vein systolic filling fraction (HVFF); HV systolic filling fraction (HVFF) HV systolic filling fraction (HVFF), 1144 Hydatid cyst, 1491, 1493f–1497f, 1493f–1498f pericardial, 1497f–1498f Hypereosinophilic cardiomyopathy, 1402 Hypereosinophilic syndrome, 1868–1869, 1870f Hypertension, three-dimensional speckle tracking and, 376t Hyperthyroidism, 1879, 1880f Hypertrophic cardiomyopathy, 395 three-dimensional speckle tracking and, 376t Hypertrophic cardiomyopathy (HCM), 1348–1368 alcohol septal ablation, 1362–1363 apical, 1356 definitions and types of, 1349–1356 diastolic dysfunction, 1356 differential diagnosis, 1359–1360 athlete’s heart, 1359–1360, 1361f LV noncompaction, 1359 dual chamber pacing for, 1363 endocarditis prophylaxis, 1363–1364 hypertrophied heart in, 1363f and latent obstruction, 1355f with mid–left ventricle (LV) obstruction, 1357f mid-left ventricular, 1356–1358 mitral apparatus and regurgitation, 1354–1356 obstructive, 1355f, 1360f overview, 1348 patterns of hypertrophy in, 1349f risk of SCD and, 1350 stress echocardiography in, 1318 sub-basal, 1349f systolic anterior motion of mitral valve, 1350–1354, 1350f systolic dysfunction and, 1356– 1358 treatment of, 1361–1362 pharmacologic therapy, 1361 “resect-plicate-release” operation, 1362 surgical myectomy, 1361–1362, 1362f Hypertrophic cardiomyopathy (HCM) mutations, TD imaging in, 351 Hypertrophic obstructive cardiomyopathy (HOCM), 1260

Hypertrophied heart, in HCM, 1363f Hypertrophy definition, 1349 patterns in HCM, 1349f Hypoplastic left heart syndrome (HLHS), 1540, 1549f, 1550f–1551f, 1701, 1784 velocity vector imaging in, 393–394 Hypoplastic mitral valve, 1613 Hypovolemia, 1977, 1978f hyperkinetic, 1978 hypotension, 1977 hypotensive, patient, 1978f hypo-volemia, 1977

I ICE. See Intracardiac echocardiography (ICE) ICM. See Ischemic cardiomyopathy (ICM) IEC 60601-1 document, on safety of medical electronic devices, 110 Image line density, and frame rate, 59 Image optimization and equipment, 60 depth and, 61 focus and, 61 gain and, 61 sector width and, 61 zoom and, 61 Image rendering, in 3D echocardiography 2D tomographic slices, 79–80 surface rendering, 79 volume rendering, 78–79, 79f Imaging artifact, 3D reconstruction imaging and, 17 IMH. See Intramural hematoma (IMH) Impella catheter-based assist device, 1227 Impella device, 1250, 1251f Individual mitral lesions, evaluation of, 1611–1615 abnormal mitral arcade, 1613–1614 accessory mitral orifice, 1615 cleft mitral leaflet, 1613 double orifice mitral valve, 1614– 1615, 1614f dysplasia of mitral valve, 1613 Ebstein’s anomaly of mitral valve, 1615 hypoplastic mitral valve, 1613 mitral valve prolapse, 1615 parachute mitral valve, 1613 supramitral ring or membrane, 1611–1613 Indocyanine green, 11

Index

Infectious cardiomyopathy, 1405–1407 HIV-associated cardiomyopathy, 1407 septic cardiomyopathy, 1405–1407 Infective endocarditis aortic abscess in native valve, 1045f transesophageal approach, 1053f aortic insufficiency, massive, 1046f Candida albicans, 1044f in childhood, 1856–1857 diagnosis of, 1059 Duke criteria for, 1042, 1043t false-positive results in, 1045t echocardiography in findings, 1043–1047 goals of, 1042–1043 indications of, 1058–1059, 1059f metallic aortic valve prosthesis, infected, 1057f prognostic stratification, role in, 1050–1058 sequential transesophageal, 1051f–1052f three-dimensional, 1049–1050, 1050f–1058f overview, 1042–1043 periannular extension of, 1044–1045 pericardial effusion, 1045–1047 prosthetic valve, 1047 abscess in patient with mechanical, 1047f dehiscence, 1047 “prosthetic pitch,” 1047 pseudoaneurysm in aortic annulus, 1046f aortic valve, 1046f right-sided, 1047–1049 transesophageal approach, 1048f type of patient with, 1048–1049 special considerations in, 1047–1050 tricuspid valve endocarditis, 1058f valve perforation, 1045, 1046f bicuspid aortic, 1046f native mitral, 1046f, 1056f vegetations, 1043–1044, 1044f on bicuspid aortic valve, 1044f fungus infection, 1054f large aortic, 1044f, 1053f on mitral native valve, 1046f, 1050f transesophageal approach, 1053f Infective endocarditis prophylaxis, 1859 Inferior vena cava (IVC), 1063, 1143–1144, 1532f, 1964

abnormalities of, 1682–1683 bilateral, 1683 inferior vena cava interruption, 1682–1683 inferior vena cava to left atrium, 1683 cannula position in, 1252f dilated, 1066f in dilated cardiomyopathy, 1373– 1374, 1374f hepatic vein, 1964 heterotaxy syndrome and, 1705–1706 inspiratory collapse, 1964 plethora (dilation) of, 1441f pulse Doppler across, 1539f for RAP, 1264–1266, 1266f size, 1964 subcostal window, 1964 thrombi, 1966 transgastric level, 1964 ventricular assist devices and, 1233 Inferior vena cava interruption, 1682– 1683 Ingenious balloon, 535 Inkjet technology, 6 Inlet VSD, 1659 Instrumentation, Doppler, 66–68 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS), 1224, 1226 Interatrial communication, TGA and, 1657 Interatrial membrane, color Doppler across, 1532f INTERMACS. See Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Internal carotid artery (ICA), 665–668 International Electrotechnical Commission (IEC), 110 International Registry of Acute Aortic Dissection study, 980 International Society of Cardiovascular Ultrasound (ISCU), 753, 758 Interrupted aortic arch, 1694–1695, 1695f classification of, 1695t type B arch interruption, 1694 Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL), 132 Interventricular septum (IVS), 1534f Intra-aortic balloon pump, and carotid ultrasound findings, 693 Intracardiac echocardiography (ICE), 643–653 advantages of, 652

clinical applications, 644 during electrophysiology intervention atrial septal puncture, 644–645, 646f EP procedures and, 647–648 pulmonary vein isolation for atrial fibrillation ablation, 645, 647, 647f right ventricular outflow tract tachycardia, 647, 648f ventricular tachycardia from left ventricle, 647, 649f VT foci from great vessels, 647, 648f–649f equipment and catheters, 643 mechanical system, 643 phased array ultrasound system, 644, 644t extracardiac use of, 651, 652f imaging specifications, 644, 645f limitations of, 652 during structural intervention Melody valves, 651 patent foramen ovale/atrial septal defect closure, 648, 650, 650f periprosthetic valve, 650–651, 651f ventricular septal defect closure, 650, 651f three-dimensional, 652, 653f Intracardiac hardware, 1514–1517 Intramural hematoma (IMH), 957–958, 958f transesophageal imaging of, 978 Intrauterine growth retardation (IUGR), 1528 Intravascular ultrasound (IVUS), 643, 655–661 examination procedure, 656–657 future perspectives, 661 image acquisition, 655–656 electronically switched multielement array system, 656 mechanically rotating transducer, 655–656 image interpretation, 657–659, 658f, 659f safety of, 661 technology, 655 utility of, 659–660, 660f Ischemic and nonischemic cardiomyopathy cardiac magnetic resonance imaging, 1427–1428 cronary computed tomographic angiogram, 1427

I-XIX

doppler echocardiography, 1421– 1424 coronary echocardiography, 1424 left atrial size, 1422 left ventricular diastolic dysfunction, 1422 left ventricular end-systolic volume index, 1421–1422 left ventricular volumes, 1421 mitral regurgitation, mechanism, 1422–1424, 1423f myocardial contrast echocardiography, 1424 right ventricle dysfunction, 1422 stress echocardiography, 1424 tenting area, 1422, 1423f echocardiographic assessment, 1419 echocardiographic differentiation of, 1418–1434 large mitral–septal separation, 1419 M-mode echocardiography, 1419– 1421 overview, 1418 positron emission tomography, 1428 severely dilated left ventricular cavity, 1419 single-photon emission computed tomography, 1425–1427 Ischemic cardiomyopathy (ICM), 1388– 1395, 1395f, 1418, 1420ff–1421f vs. NICM, 1425, 1426t Ischemic cascade, 1307f Ischemic handgrip, 453 Ischemic heart disease, 1289–1305 central mitral regurgitation and, 1298f chronic. See Chronic ischemic heart disease detection of, 1289–1292 pharmacological stress testing, 1290 stress echocardiography for, 1289– 1291, 1290f vasodilator stress testing, 1290 echocardiography in myocardial contrast stress, 1291–1292 speckle-tracking, 1301–1303, 1303f three-dimensional, 1301–1302 overview, 1289 Ischemic LV dysfunction, 3D speckle tracking and, 376t Ischemic mitral regurgitation, 858–863 Isolated carditis, 774–775 Isolated mitral valve cleft, 1775 Isomerism, echocardiography of, 1577 Isomerism syndromes. See also Heterotaxy syndrome

I-XX


cardiac and extracardiac anomalies in, 1705f venoatrial connections in, 1706t Isovolumic contraction (IVC), 1185–1186 Isovolumic contraction time (IVCT), 1140 Isovolumic relaxation time (IVRT), 313, 1069t, 1140 IUGR. See Intrauterine growth retardation (IUGR) IVC. See Inferior vena cava (IVC) IVCCI. See IVC collapsibility index (IVCCI) IVC collapsibility index (IVCCI), 1265 IVCT. See Isovolumic contraction time (IVCT) IVRT. See Isovolumic relaxation time (IVRT) IVUS. See Intravascular ultrasound (IVUS) IVUS with virtual histology (IVUS-VH), 657

J Jarvik-2000 Flowmaker, 1228, 1228f Joyner, Claude, 6 Junctional rhythm, and PV Doppler, 333, 334f

K Kaul, Sanjiv, 13 Kawasaki disease (KD), 1688–1689 in childhood, 1861 coronary arteries with, 1862t velocity vector imaging in, 398

L LAD. See Left anterior descending (LAD) LaGrangian strain, 389 Lambl’s excrescences, 1015, 1480f LAP. See Left atrial pressure (LAP) Large intracardiac thrombus, 1978 atrial appendage, 1978 atrial fibrillation, 1978 atrial flutter, 1978 autopsy, 1979 deep venous thrombosis, 1979 disystole, 1978 echolucent, 1979 endocardium, 1978 heart embolism, 1978 intracardiac devices, 1979 systole, 1978

transthoracic echo, 1979 transthoracic images, 1979 ventricular apex, 1979 Lariat procedure, 563, 566, 566f–568f Laser Doppler flowmetry (LDF), 469–470 Laser Doppler perfusion monitoring (LDPM). See Laser Doppler flowmetry (LDF) Late gadolinium enhancement (LGE), 2003, 2020 Latent diastolic dysfunction, stress echocardiography in, 1318 Lateral resolution, 59, 59f, 733, 734f Lavengin, Paul, 4 LBBB. See Left bundle branch block (LBBB) Lead infection, associated with pacemaker, 1114–1115 Lead perforation, 1215–1217 chest CT for, 1216 echocardiography in, 1216f reported cases of, 1217t Lead zirconate titrate (PZT), 1992 Leakage current., 110–111, 111f, 111t Left anterior descending (LAD), 1337 artery disease, 1328 distal post-stenotic diastolic-to systolic velocity ratio, 1340–1341 Left atrial appendage (LAA), 1960 abnormalities, 1960 adequate visualization, 1960 clot detection 3D TEE for, 512, 619 continuous wave, 1963f 3DE assessment of, 277, 277f doppler interrogation, 1960 embolism, 1960 endocardial device closure of, 561–563, 562f–565f epicardial suturing of. See Lariat procedure exclusion, 1961 percutaneous, 561 surgical, 560–561 mid-diastolic signals, 1960 mitral valve, surgery, 1960 orthogonal mass abnormality, 1960 pectinate lines, 1960 persistence, 1961 prominent ridges, 1960 recanalized, 1963f thrombus, 1960 traverse, 1962f Left atrial appendage clot, embolization of, 1917f Left atrial appendage thrombus, 2058f

Index

Left atrial function, 1255–1263 anatomy of, 1255 cardiac cycle and, 1256f functional assessment, 1257–1259 LA volume, 1257, 1258f speckle tracking, 1259, 1259f spectral Doppler, 1257–1259 left atrial size, 1257, 1258f overview, 1255 overview of, 1255 pathophysiology, 1259–1261, 1260f atrial fibrillation, 1259–1260 cardiac amyloidosis, 1261f cardiomyopathies, 1260, 1260f hypertension, 1259 physiology of, 1256 phasic left atrial function, 1256 physiological effects on, 1257 pressure-volume relationship of, 1256f Left atrial hemangioma, 1487f Left atrial leiomyosarcoma, 1488f Left atrial myxomas, 845, 1467f, 1472, 1474f, 1475f Left atrial pressure (LAP), 1279, 1281f Left atrial septal myxoma, 1469f Left atrium, 1960 ablation therapies, 1960 anteroposterior dimension, 1960 arrhythmias patients, 1960 atrial arrhythmias patients, 1960 atrial flutter, 1960 doppler, 1961 color flow, 1961 pulsed, 1961 echocardiographer, 1960 echodense mass, 1962f index, 1960 latrial tachycardia, 1960 left atrial appendage, 1960 abnormalities, 1960 adequate visualization, 1960 continuous wave, 1963f doppler interrogation, 1960 embolism, 1960 exclusion, 1961 mid-diastolic signals, 1960 mitral valve, surgery, 1960 orthogonal mass abnormality, 1960 pectinate lines, 1960 persistence, 1961 prominent ridges, 1960 recanalized, 1963f thrombus, 1960 traverse, 1962f

left upper pulmonary vein, 1962f M-mode echocardiography, 1960 pectinate muscles, 1962f pulmonary veins, 1960, 1961f rhythm analysis clues, 1960 spontaneous echo contrast, 1960 swirling appearance, 1960 thromboembolic, 1960 complications, 1960 event, 1960 nonvalvular, 1960 risk, 1960 valvular, 1960 transesophageal echocardiogram, 1961f volume, 1960 Simpson’s biplane method, 1960 Left atrium myxoma, 2053f Left bundle branch block (LBBB), 1217, 1377 Left heart hemodynamics, age groups for, 1275t Left isomerism, 1577 Left lower pulmonary vein (LLPV), 327, 328f Left main coronary artery (LMCA) flow in distal, detection of, 1340 transesophageal echocardiography, 1338–1340, 1339f transthoracic echocardiography, 1337–1338, 1339f Left main coronary artery ostium, 647 Left main coronary artery stenosis (LMCAS), 1325 Left parasternal approach, of three dimensional echocardiography, 244, 245f–254f Left-sided filling pressures, 1273–1279 color M-mode flow propagation velocity, 1278 echocardiographic methods for, 1273t–1274t evaluation of, 1277f variables used for, 1278t left atrial dimensions, 1278–1279 mitral inflow parameters in, 1274– 1276, 1275f, 1275t pulmonary venous flow and, 1276, 1276f tissue Doppler annular diastolic velocities, 1277–1278 Left-sided superior vena cava (LSVC), 1535, 1545f Left upper pulmonary vein (LUPV), 327, 328f, 1962f

Left ventricle, 1185–1194, 1246–1248 apical velocity rotation and timing for, 1202f isovolumic contraction, 1185–1186 lengthening, 1189 postejection isovolumic phase, 1188–1193, 1192f rapid filling, 1193–1194, 1193f recoiling, 1189 torsion, 1186–1188 ventricular assist devices and, 1229–1230 Left ventricle, 3D quantitation of, 1149–1165 2D echocardiography, limitations of, 1149–1152 apical foreshortening, 1152 boundary recognition, 1152 3D spatial coordinates, lack of, 1149–1151 geometric assumptions, 1151 3D reconstruction, 1152f limitations of, 1152 freehand scanning, 1150f real time 3D ecocardiography, 1152–1156, 1152f data acquisition, 1153–1155, 1154f, 1155f first-generation matrix array transducer, 1153 left ventricular strain, 1157–1161, 1159f, 1160f left volumes and EF, validation of, 1156–1157 peak filling rate from, 1158f for postmyocardial infarct risk stratification, 1165 third-generation systems in, 1155– 1156 regional segments of, 1162f, 1163f serial evaluation of patients with 3DE, 1164–1165 Left ventricle apical ballooning syndrome, 1388 Left ventricle twist, 276 Left ventricle underfilling, 1246f causes, 1247t evidence of, 1246–1248 Left ventricular aneurysm, 1295f, 1298 Left ventricular apical thrombus, 1299f Left ventricular assist devices (LVAD), 1204 and carotid ultrasound findings, 693–694 complications of, 1240–1246

I-XXI

computed tomography and, 2063– 2064 left ventricular overfilling, 1240–1246 causes, 1245t mitral flow prior to placement of, 1243f net forward cardiac output and, 1247–1248 optimizing settings, 1248–1249, 1250f placement response of, factors affect, 1235f power failure of, 1244f structures in patient with, 1239f transesophageal echo, postoperative, 1237f Left ventricular diastolic dysfunction grades of, 1127f ICM/NICM and, 1422 left atrial dilation in patient with, 1125f Left ventricular diastolic function 2D echocardiography, 1124–1125 flow propagation velocity, 1127 color Doppler, 1129f future directions for, 1131–1132 imaging techniques for, 1131–1132 integrating echocardiographic variables, 1130–1131, 1130f–1131f left atrial size, 1124–1125 left ventricular mass, 1124–1125 in nonsinus rhythm, 1129–1130 overview, 1124 pulmonary artery pressure, 1129 pulmonary artery systolic pressure and, 1130f pulmonary venous flow, 1127–1128 tissue Doppler imaging for, 1127, 1128f Valsalva maneuver, 1126–1127 wall function, 1124–1125 Left ventricular dimensions, 1942–1943 Left ventricular dysfunction, ultrasound stethoscope for screening of, 295 Left ventricular dyssynchrony, 1218 three-dimensional speckle tracking and, 376t Left ventricular ejection fraction (LVEF), 381, 1116, 1117, 1124–1125 in LFLG-AS, 1929 pacemaker and, 1218f systolic myocardial dysfunction and, 1131f Left ventricular end-diastolic diameter (LVEDD), 1886

I-XXII


Left ventricular end diastolic pressure (LVEDP), 1277, 1279, 1280f, 1375, 1375f Left ventricular end-diastolic pressure (LVEDP) assessment of, 334–335, 334f, 335f Left ventricular end-diastolic volume (LVEDV), 271 Left ventricular end-systolic diameter (LVESD), 1886 Left ventricular end-systolic volume (LVESV), 271 Left ventricular filling pressure demonstration of elevated, 1126– 1130 restrictive transmitral filling pattern, 1126f transmitral diastolic inflow for, 1126f Left ventricular free wall, rupture of, 1294 Left ventricular geometry, partitions value of, 1887f Left ventricular hypertrophy (LVH), 294, 351, 352, 1125f, 1871, 1933–1934, 1974 in female, 1911f Left ventricular internal dimension in diastole (LVIDd), 1118 Left ventricular internal dimension in systole (LVIDs), 1118 Left ventricular intracardiac metastasis, 1499f Left ventricular lipoma, 1482f Left ventricular mass, 1124–1125, 1942–1943 Bland–Altman analysis, 1162 3D echocardiography, 1161–1162 epicardial and endocardial borders, 1161f partitions value of, 1887t RT 3DE for, 1162 Left ventricular myxomas, 1474 Left ventricular noncompaction (LVNC), 395–396, 1384–1388, 1385f, 1389f–1391f, 1394f cardiac MRI for, 2000–2002, 2001f, 2002f echocardiographic features of, 1385–1388, 1386f–1387f isolated, 1387f, 1393f normal fetal ontogenesis, 1385 Left ventricular opacification (LVO), 421, 426 Left ventricular outflow tract (LVOT) forms of, 897t in prosthetic valves, 1084

Left ventricular outflow tract (LVOT) obstruction, 1350–1354 anomalous papillary muscle and, 1354f aortic regurgitation, 1628–1630 aortocameral communications, 1632 conversely, dynamic, 1353–1354 echocardiographic evaluation of, 1351–1352, 1352f sinus of Valsalva aneurysm, 1630– 1632 subvalvular aortic stenosis and, 1624–1626 supravalvular aortic stenosis and, 1626–1628 systolic anterior motion and, 1350 TGA and, 1659–1661 valvular aortic stenosis and, 1618– 1624 vs. mitral regurgitation, 1353f Left ventricular overfilling, 1240–1246 Left ventricular pseudoaneurysm, 569, 1294–1295 closure of, 571, 571f Left ventricular quantification, 3D echocardiography and, 82–85, 84f Left ventricular-RA communication, 1779–1782 Left ventricular remodeling, 3D echocardiography, 1162–1164 Left ventricular systolic function, 1115–1123 arterial–ventricular coupling, 1121–1122 assessment of, 1116–1119 biplane method of discs, 1118–1119 blood supply from particular coronary artery, 1116 contrast echocardiography of, 1121, 1121f Doppler echocardiography of, 1119 2D speckle tracking echocardiography, 1120 fractional shortening at endocardium, 1118 longitudinal fiber shortening, 1119 M-mode echocardiography, 1116– 1119 E point septal separation, 1117 left ventricular ejection fraction, 1116, 1117 parasternal long-axis, 1116 modified cylinder-ellipse formula, 1118f myocardial contractile velocity and, 1119

Index

myocardial performance index, 1120 overview, 1115 Quinones method, 1117 seventeen-segment model, 1116f sphericity index, calculation of, 1119 Tei's index, 1120, 1120f tissue Doppler imaging, 1119 transthoracic echocardiography three-dimensional, 1122 two-dimensional, 1116–1119 velocity vector imaging, 1120 visual estimation of, 1115–1116 Left ventricular thrombus, 1504–1506 Left ventricular volumes assessment of, 81 in ICM/NICM, 1421 Leiomyosarcoma, 627 aortic, 1489f–1490f left atrial, 1488f Levacor ventricular assist device, 1228 Levo-transposition of great arterie, 1759f Levo transposition of great vessels, in female, 1916f LFLG-AS. See Low-flow, low-gradient aortic stenosis (LFLG-AS) Libman–Sacks endocarditis, 1867–1868, 1868f Libman-Sacks vegetations, 931 Lidocaine, 508 Light and sound, 1995, 1996 acousto-optical imaging, 1996 complementary approach, 1996 endogenous absorbers, 1995 laser pulses, 1995, 1996 precision, 1995 photoacoustic imaging, 1995 Schlieren tank, 1996 classic implementation, 1996 Linear array system, 8 Linear/phase array transducers, 76, 76f Linear probe, 58, 58f Line density, 60 Lipoma, 2054f Lipomatous hypertrophy of atrial septum, 1484f of interatrial septum, 182, 182f, 533, 536f, 2054, 2056f Live 3DE, 269 Liver cirrhosis, and HV Doppler, 318, 319f Liver disease, and HV Doppler, 318–319, 319f LMCA. See Left main coronary artery (LMCA) LMCAS. See Left main coronary artery stenosis (LMCAS)

Lobster claw abnormality, 1352f, 1358, 1358f Loeffler endocarditis, 1403f–1404f Loeffler’s syndrome, 1006–1007, 2009f 2d transthoracic echocardiography, 1008f, 1009f Loeys-Dietz syndrome, 958 LOLIPOP. See London Life Sciences Prospective Population (LOLIPOP) study London Life Sciences Prospective Population (LOLIPOP) study, 272, 1157 Longitudinal fiber shortening, 1119 Longitudinal peak systolic strain (LPSS), 1069t Longitudinal strain, 362, 363f, 389 Long-term axial flow devices, 1227–1228 Berlin heart incor assist device, 1228 HeartAssist system, 1228 HeartMate II continuous flow LV assist device, 1228 Jarvik-2000 Flowmaker, 1228, 1228f Long-term third generation centrifugal flow systems, 1228–1229 DuraHeart magnetically levitated centrifugal assist system, 1228 EvaHeart left ventricular system, 1228–1129, 1228–1229 HeartWare ventricular system, 1224f, 1228 Levacor ventricular assist device, 1228 Lower bound velocity (LBV), 88 Low-flow, low-gradient aortic stenosis (LFLG-AS) with ejection fraction, 1929 with low ejection fraction, 920–921 SAVR in, 927 with normal ejection fraction, 921–924 Low flow-mediated vasoconstriction (LFMC), 470–471, 470f–474f Low MI imaging, 420 Low transvalvular gradients, aortic stenosis with, 913 LPSS. See Longitudinal peak systolic strain (LPSS) LSVC. See Left-sided superior vena cava (LSVC) Lung artifact, 227 Lung carcinoma, 1459f Lung ultrasound scan (LUS), 1982, 1983 aerated lung, 1982

cardiogenic watery B-lines, 1982, 1983 differential diagnosis challenge, 1982 extravascular lung water, 1982 human acute respiratory distress syndrome, 1983 limitations, 1987 B-line interpretation, 1987 obese patients, 1987 patient-dependent, 1987 lung sliding, 1982 main approaches, 1983 methodology, 1983, 1984 pulmonary parenchyma, 1983 thoracic scanning areas, B-lines semiquantitative assessment, 1983, 1984f two-dimensional scanner, 1983 physical basis, 1982, 1983 physical scatterer, 1982 physiological basis, 1982, 1983 pulmonary edema, 1983 sonographic appearance, 1982, 1983f consolidated lung, 1983f multiple B-lines, 1982, 1983f normal lung, 1983f LUPV. See Left upper pulmonary vein (LUPV) LVAD. See Left ventricular assist device (LVAD) LV concentric hypertrophy, 920 LV contractility, reduction in, 920 LV diastolic function, assessment of, by TD imaging, 352–353, 355f, 356f LV dyssynchrony, TD Imaging for, 353, 354f LVEDD. See Left ventricular end-diastolic diameter (LVEDD) LVEDP. See Left ventricular end diastolic pressure (LVEDP) LVEDV index, 1157 LVEF. See Left ventricular ejection fraction (LVEF) LV ejection fraction (LVEF), 270 in acute coronary syndromes, 1293–1294 LVESD. See Left ventricular end-systolic diameter (LVESD) LVESV index, 1157 LV filling pressures, estimation of, by TD imaging, 352–353 LVIDd. See Left ventricular internal dimension in diastole (LVIDd)

I-XXIII

LVIDs. See Left ventricular internal dimension in systole (LVIDs) LV noncompaction, three-dimensional speckle tracking and, 376t LVOT. See Left ventricular outflow tract (LVOT) LVOT geometry, aging and, 1943 LVOT velocity time integral, in LFLG-AS, 1929 LV regional function, 3DE assessment of, 271–272, 276 aortic stenosis, 279 aortic valve assessment, 278f, 279, 279f contractile reserve, 276 left and right atria, 276–277, 277f left ventricle twist, 276 right ventricle, 277–278 valvular assessment, 278, 278f LV systolic dysfunction, 3D speckle tracking and, 376t LV volume assessment, 3D speckle tracking and, 376t LV wall motion abnormalities three-dimensional speckle tracking and, 376t Lymphomas, 1500f, 2054 primary cardiac, 1490

M MAIN-COMPARE trial, 659 Major adverse cardiovascular events (MACE), 2042 Malignant melanoma, 1500 Malignant primary cardiac tumors, 1484–1511 angiosarcoma, 1485–1486 cardiac plasmacytoma, 1490–1491, 1492f fibrosarcomas, 1488 hydatid cyst, 1491, 1493f–1498f pericardial mesotheliomas, 1491 primary cardiac lymphoma, 1490 rhabdomyosarcoma, 1486–1488 sarcomas, 1484–1488 Manometers, 27 Marfan syndrome (MFS), 958–959 TAA and, 1936 Matrix biplane transesophageal echo (TEE) probe, 99–100, 100f MDCT. See Multidetector computed tomography (MDCT)

I-XXIV


Mean left atrial pressure, assessment of, 335, 335f Mean pulmonary artery pressure (MPAP), 1063, 1064t, 1065t, 1066, 1272, 1272f, 1901 Mechanical index (MI), 57, 111, 418–419 high, 422–423 low, 423 Mechanical safety, TEE probe examination and, 111–112 Mechanical valves, 1082 bileaflet, 1083t, 1085f single disc, 1083t Melody valves, 651 Membranous subaortic stenosis, 1625 Mesothelial/macrophage incidental cardiac excrescences, 1511–1518 cardiac calcified amorphous tumor, 1512–1514 extracardiac masses, 1514, 1514f intracardiac hardware, 1514–1517 mitral annular calcification, 1512, 1512f Metabolic cardiomyopathy, 1407 Metastasis, 2053–2054 from melanoma, 2055f Metastatic left pleural effusion, in female, 1913f Metastatic melanoma, 1499f involving right ventricle, 1499f Micro-beam forming, 78 Microbubbles, 1993, 1994 first human studies, 1993 future potential, 1993 liver metastasis, 1993, 1994f macro/microvascular systems, 1993 mechanical index, 1993 microbubble lymphangiography sentinel lymph node, 1993, 1994f preclinical work, 1993 ultrasound contrast, 1993 VEG-F2 study, 1993 Mid-left ventricular hypertrophic cardiomyopathy, 1356–1358 Midmuscular ventricular septal defect, 1544f Midwall fractional shortening (MWFS), 1118 Miniaturization technology, 102–103, 103f, 104f MinivisorTM, 291, 292f Mirror image artifacts, 735–736. See also Artifacts MitraClip® device, 539 Mitral annular calcification (MAC), 1512, 1512f, 1895f, 1946–1948 in elderly, 1946–1948

Mitral atresia, 1552f, 1701–1704 associated systemic venous anomalies, 1702–1703 apical four-chamber view, 1703 parasternal views, 1703 subcostal view, 1702–1703 suprasternal notch view, 1703 echocardiography after stage 1 palliation, 1703–1704 Mitral prosthetic regurgitation, 1106f, 1107f–1108f paravalvular, 1102f–1104f Mitral regurgitation (MR), 791–801, 880–895, 1972, 1974f acute, 1972 acute vs. chronic, 885 cardiac MRI for, 2012–2013 chronic asymptomatic, sequential evaluation of, 890–892 BNP levels, 891 Doppler echocardiography, 891–892 follow-up in, 890–891 chronic functional, 884f classifications, 1973t color Doppler, 1973t, 1974f, 1975f, 1975t Doppler vena contracta, 1973t, 1975t regurgitant fraction, 1973t, 1975t regurgitant orifice area, 1973t regurgitant volume, 1973t, 1975t color flow imaging, 885 continuous wave Doppler, 886 continuous wave Doppler signal of, 1279 3DE assessment of, 282–283, 282f, 283f echocardiographic criteria for, 889t endocarditis, 1972 etiology of, 880–884 exercise echocardiography, role of, 892–893 hemodynamically stable, 1972 hemodynamic consequences of, 889–890 left atrium, 890 left ventricle, 889–890 pulmonary arterial pressure, 890 right ventricle, 890 ICM/NICM and, 1422–1424, 1423f mechanism of, 884–885 functional classification, 884 jet direction, 884–885 mitral valve repair, feasibility of, 892 overview, 880 papillary muscle, 1972

Index

pap muscle dysfunction, 1972 primary, 880–883 leaflets, 880–883 mitral annulus, 883 subvalvular apparatus, 883 pulmonary venous flow, 886 and PV Doppler, 336–338, 337f, 338f rupture, 1972 secondary, 883–884 left ventricular remodeling, 883–884 mitral annulus, 883 mitral valve distortion, 883–884 severity of, 885–889 grading of, 888 qualitative assessment of, 885–886 quantitative assessment of, 886–888, 888f semiquantitative assessment of, 886 surgical correction of, 538–540, 541f, 542f transesophageal echocardiography, 1972 vena contracta, 886 Mitral regurgitation, echocardiographic assessment of, 847–863 causes of, 848t echocardiography, role of, 848t etiology and mechanism of, 848–849 hemodynamic consequences, 874–876 left atrial size and pulmonary pressures, 876 left ventricle size and function, 874–876 key notes, 847–849 mitral valve prolapse, 849 severity of, 863–876 antegrade velocity of mitral inflow, 869 color Doppler jet area, 863–868 continuous-wave jet intensity, 869 echocardiographic assessment of, 864t PISA method, 870–871 pulmonary venous flow, 869 quantitative echo/Doppler methods, 869–874 semiquantitative echo/Doppler methods, 863–869 vena contracta width, 868–869 surgical considerations in, 876 Mitral stenosis, 776–791 anterior mitral valve leaflet, 777, 780f associated lesions, 783–784 cardiac MRI for, 2013

continuity equation, 789 3DE assessment of, 280, 281f, 282 echocardiography exercise, 790 pitfalls of using, 790–791 recommendations for, 778t three-dimensional, 791 two-dimensional, 778–779, 779f mitral valve, assessment of, 779–783 abnormal motion of leaflets, 779–781 commissural fusion, 781–783 PISA method, 789 planimetry, 785 pressure gradient, 785–787 pressure half-time, 787–789 and PV Doppler, 338–339, 339f severity classification of, 784t determination of, 784–785 indices of, 789–790 methods for quantification of, 785t Mitral stenosis, echocardiographic assessment, 826–847, 827f anatomic considerations, 826–827 atrial septal defects, 842 balloon mitral valvotomy, 839t, 842f complications of, 840–841 echocardiography in patients for, 838–840 evaluation of patient, 838–840, 839t mitral regurgitation in, 840–841 post, 841f, 843f, 844f cardiac perforation, 841–842 causes of, 846–847 conditions clinically mimicking rheumatic, 844–846 atrial ball valve thrombus, 845 congenital double orifice mitral valve, 844–845 congenital mitral stenosis, 844 congenital parachute mitral valve, 845, 846f degenerative mitral valve stenosis, 844 left atrial myxoma, 845 diseases of other valves, 834–836 echocardiography in balloon mitral valvotomy, 838–840, 839t exercise, 844 role of three-dimensional, 844 two-dimensional, parameters of, 827 indices of severity, 829–834 continuity equation, 833 diastolic pressure gradient, 829–831

mitral valve area planimetry, 831 PISA method, 834 pressure half-time, 831–833, 832t, 833f Wilkins Score, 830t left atrium, 834 left atrium appendage, 834 long-term outcome, 842–843 mitral regurgitation and, 834–836 mitral valve morphology, 827–829 leaflet motion, 828 subvalvular pathology, 828 valve calcification, 828–829 valve thickening, 827–828 normal mitral valve area, 827 pulmonary hypertension, 836–838 mitral valve echocardiographic scoring system, 836 Wilkins scoring system, 836–837 rheumatic, 827 RT 3DE scoring system, 838t Mitral valve (MV), 577–579, 578f, 579f in adults, 1818–1820 cleft, 1818–1819 cor triatriatum, 1818 double orifice mitral valve, 1819–1820 echocardiography, 1818 mitral regurgitation, 1820 parachute, 1820 anatomy, assessment of Cormier score, 782t Wilkins score, 782t anatomy of, Cormier Score, 837t 3DE assessment of, 278, 278f, 280, 281f 3D echo of, 516–520, 517f, 518f pulsed wave Doppler across, 1533f real time 3D echocardiographic score of, 783t short-axis, 1533f Mitral valve, congenital anomalies of, 1610–1615 individual mitral lesions, evaluation of, 1611–1615 abnormal mitral arcade, 1613–1614 accessory mitral orifice, 1615 cleft mitral leaflet, 1613 double orifice mitral valve, 1614– 1615, 1614f dysplasia of mitral valve, 1613 Ebstein’s anomaly of mitral valve, 1615 hypoplastic mitral valve, 1613 mitral valve prolapse, 1615 parachute mitral valve, 1613

I-XXV

supramitral ring or membrane, 1611–1613 mitral valve lesions, echocardiographic views, 1610–1611 types of, 1611t Mitral valve area (MVA), 282 Mitral valve calcification, 1889 in women, 1889 Mitral valve diseases, 775–776, 826–879, 1318 anatomy of mitral valve, 775–776 mitral regurgitation, 791–801 assessment of, 793 color Doppler flow, 793–796 continuous wave Doppler, 796–797 exercise echocardiography, 800 follow-up in, 801 pulmonary vein flow, 798 pulsed Doppler, 797–798 severity of, 793 integrative approach for, 800–801 organic, 801t role of TEE in assessing, 788–800, 799t supportive signs, 798 three-dimensional echocardiography, 800 two-dimensional echocardiography, 792–793 mitral stenosis, 776–791 overview of, 826 role of 3D TEE in operating room in, 577–582, 578f–593f stress echocardiography in, 1318 Mitral valve insufficiency, 1860f Mitral valve lesions, echocardiographic views, 1610–1611 Mitral valve morphology, 827–829 leaflet motion, 828 subvalvular pathology, 828 valve calcification, 828–829 valve thickening, 827–828 Mitral valve opening, and untwisting, 1200–1201 Mitral valve orifice area (MVOA), 777, 790–791 continuity equation, 789 mitral PHT and, 787–789 Mitral valve performance, 1249 Mitral valve prolapse, 169 3D TTE and, 282, 282f ultrasound stethoscope for screening of, 295 Mitral valve prolapse (MVP), 849–863, 1615

I-XXVI


echocardiographic assessment of, 850–855 M-mode, 850 three-dimensional, 851–855 two-dimensional transesophageal, 851, 855f, 856f two-dimensional transthoracic, 851, 852f–855f surgical methods and indicators in, 855–863 degenerative mitral regurgitation, 863 functional mitral regurgitation, 857–858 infective endocarditis, 863 ischemic mitral regurgitation, 858–863 rheumatic mitral regurgitation, 863 tricuspid and pulmonary valve prolapse with, 855f in women, 1888, 1888f–1889f Mitral valve quantification three-dimensional echocardiography and, 81–82, 82f, 83f Mitral valve segmentation analysis, 881f Mitral valve stenosis, in female, 1888– 1889 Mitral valve vegetation, in female, 1911f Mitral valvular verrucous nodules, 773f M-mode echocardiography, 3, 3f, 58, 58f, 119–130 development of, 4–7 in left ventricular systolic function, 1116–1119 E point septal separation, 1117 left ventricular ejection fraction, 1116, 1117 parasternal long-axis, 1116 in right ventricle, 1136–1138 transthoracic echocardiogram, 136, 136f of tricuspid valve, 984–986 Ebstein’s anomaly, 986f functional events, demonstrating, 984f septal leaflet, identification, 985f systolic abnormalities, 986f using contrast injections, identification, 985f Moderator band, 1503 MPAP. See Mean pulmonary artery pressure (MPAP) mPAP. See mean pulmonary artery pressure (mPAP) MSCT. See Multislice computed tomography (MSCT)

99mTc-sestamibi gated single photon computed emission tomography (GSPECT), 1157, 1159f Mucopolysaccharidosis, 931 MullinsTM catheter, 533 Multi-beat acquisition, in 3D echocardiography, 74–75, 75f Multicenter Aneurysm Screen Study (MASS), 294 Multidetector computed tomography (MDCT), 2023 acute chest pain evaluation with, 2045–2047 for coronary artery anomalies, 2047–2049 techniques of, 2047 Multigate pulsed Doppler, 70 Multipath reflection, 81 Multiplane mode, 268–269 Multiple-beat 3DE imaging, 269 Multiple thrombi, with poor ventricular function, 1377f Multislice computed tomography (MSCT), 1427 Muscular inlet defect, 1593 Muscular outlet defect, 1593 Muscular trabecular defect, 1594 Muscular ventricular septal defects, 557–558, 1593–1594, 1593f, 1594f. See also Ventricular septal defects (VSDs), closure of muscular inlet defect, 1593 muscular outlet defect, 1593 muscular trabecular defect, 1594 MV clipping, 538–540, 541f, 542f 3D TEE guidance of, 540 MitraClip device for, 539 patient selection for, 540 MVOA. See Mitral valve orifice area (MVOA) MVP syndrome (MVPS), 1888 MWFS. See Midwall fractional shortening (MWFS) Myocardial blood flow (MBF), 442 Myocardial blood volume (MBV), 422 Myocardial contractile motion, 1159– 1160 Myocardial contractile velocity, 1119 Myocardial contrast echocardiography (MCE), 416, 422, 430. See also Contrast echocardiography for CAD detection, 430–431 coronary flow reserve by, 431 for myocardial perfusion assessment, 427–428, 429f

Index

for myocardial viability detection, 431 Myocardial contrast stress echocardiography, 1291–1292 Myocardial deformation imaging, 360. See also Strain imaging Myocardial disease, detection of, by TD imaging, 350–352 Myocardial fiber organization, 1180f Myocardial infarction mechanical complications of, 1294–1298 left ventricular aneurysm, 1298–1300 left ventricular free wall, rupture of, 1294 left ventricular pseudoaneurysm, 1294–1295 papillary muscle rupture, 1297, 1297f ventricular septal rupture, 1295– 1297, 1296f speckle-tracking echocardiography, 1302 vs. cardiac death, 1311–1315 Myocardial ischemia, speckle-tracking echocardiography, 1302 Myocardial perforation, pacemaker associated, 1215–1217 2D transesophageal echocardiography in, 1216, 1216f reported cases of, 1217t RT3DE in, 1216f Myocardial performance index (MPI), 1120 ICM/NICM and, 1419 in rheumatoid arthritis, 1868 Myocardial perfusion echocardiography, 441–447 acute coronary syndromes, 443 chronic coronary artery disease, 443–445 myocardial perfusion evaluation, by CE, 441–443 nonischemic dilated cardiomyopathy, assessment of, 445–446, 447f and stress echocardiography, 1319 Myocardial tagging, 405 Myocardial viability, speckle-tracking echocardiography, 1302–1303 Myocardial viability assessment, contrast echocardiography for, 443 Myocardial wall motion abnormality, 1311 Myocarditis, velocity vector imaging in, 398–399

Myofiber structural orientation, 1183f Myxomas, 622–623, 1474f, 2051 atrial, 1468 attached to atrial septum, 1471 biatrial, 1470f left atrial, 1467f left atrial septal, 1469f right atrial, 1470f right ventricular, 1471f–1472f, 1473f ventricular, 1468–1470

N Narrow-angled display, 241 National Board of Echocardiography (NBE), 754 National Electrical Manufacturers Association (NEMA), 110 National Institutes of Health, 8 Native valve endocarditis, role of 3D TEE in operating room in, 597–604, 609f–612f Nitric oxide (NO), 454 and endothelial function, 450, 451 Nodal re-entrant tachycardia (NRT), 1957 Noninvasive hemodynamic monitoring, 229–230, 230f, 231f Nonischemic dilated cardiomyopathy (NICM), 1418 mitral–septal separation in, 1419f vs. ICM, 1425, 1426t Nonsinus rhythm, 1129–1130 Nonstandard echocardiographic examination, 188–223 abdominal examination, 220 examination from back, 216, 218, 220 two-dimensional transthoracic echocardiography, 221f left atrial appendage examination, 212, 214, 216, 217f–219f live/real-time three-dimensional transthoracic echocardiography, 217f–219f two-dimensional transesophageal echocardiogram, 219f two-dimensional transthoracic echocardiography, 217f left parasternal and apical planes for coronary arteries, 190, 204, 207, 213f–216f live/real-time three-dimensional transthoracic echocardio graphy, 214f–216f two-dimensional transthoracic echocardiography, 213f–214f

right and left supraclavicular examination, 189–190, 205f–212f live/real-time three-dimensional transthoracic echocardio graphy, 209f–212f two-dimensional transthoracic echocardiography, 205f–209f right parasternal examination planes, 188–189, 189f–204f live/real-time, three-dimensional transthoracic echocardio graphy, 196f–204f two-dimensional transthoracic echocardiography, 189f–196f Non-ST elevation myocardial infarction (NSTEMI), evaluation of, 226 No-reflow phenomenon, 443 Normal heart, 1185–1194 left ventricle, 1185–1194 isovolumic contraction, 1185–1186 lengthening, 1189 postejection isovolumic phase, 1188–1193, 1192f rapid filling, 1193–1194, 1193f recoiling, 1189 torsion, 1186–1188 sonomicrometer crystal tracings, 1203f ventricular narrowing, 1187f Nutritional deficiency, 1880 Nyquist, Harry, 70 Nyquist limit, 69, 70, 736

O Obesity, and HV Doppler, 318–319, 319f Off-axis imaging, 164 One-dimensional (1D) echocardiography, 3f, 25, 25f Optigo, 291, 292f Optison, 417, 418t. See also Contrast echocardiography Ostium primum atrial septal defect, 1586 Outflow tract obstruction, 1766–1770 congenital aortic stenosis/bicuspid aortic valve, 1766–1770 subaortic stenosis, 1770

P Paced rhythm, and PV Doppler, 334, 334f PAcT. See Pulmonary flow acceleration time (PAcT) PA diastolic pressure (PADP), 230, 231f

I-XXVII

PAH. See Pulmonary arterial hypertension (PAH) Papillary fibroelastoma, 624,1023f–1024f, 1476f–1477f on tricuspid valve, 2019f Papillary muscle rupture, 862f, 1297, 1297f PAPS. See Pulmonary hypertension (PAPS) PAPVC. See Partial anomalous pulmonary venous connection (PAPVC) Parachute mitral valve, 1613 Paradoxical low-flow, low-gradient aortic stenosis (PLFLG-AS), 921–922 cardiac catheterization and, 923 diagnosis of, 924 invasive vs. noninvasive evaluation of AS, 922–924 LVEF and, 921–922 mechanisms for, 924–925 cardiac output, 924 impaired myocardial function, 924 pseudostenosis, 925 with preserved ejection fraction, 1929–1930 SAVR in, 927 Parametric display, 708–711, 709f–711f Parasternal long-axis (PLAX) view, 1116, 1117 of aortic root, 1797f Parasternal window, TTE linear measurements, 139–141, 139f–141f ascending aorta, 140, 141f Doppler imaging, 141, 141f parasternal long-axis (PLAX) plane, 137–139, 138f, 139f, 139t M-mode imaging, 138–139, 139f technique, 137–138 two-dimensional anatomic imaging, 138, 138f, 139f, 139t parasternal short-axis plane, 144–146, 145f–147f, 145t aortic valve level, 145, 146f coronary artery imaging, 145 Doppler imaging, 146, 147f left ventricular apex level, 146, 147f linear measurements, 146 mitral valve level, 145, 146f papillary muscle level, 145, 146f technique, 144–145, 145f, 145t right parasternal long axis view, 141–142 Doppler imaging, 142 technique, 141–142

I-XXVIII


two-dimensional anatomic imaging, 142 right ventricle inflow view, 142, 142f, 142t, 143f Doppler imaging, 142, 143f technique, 142, 142f two-dimensional anatomic imaging, 142, 143f right ventricular outflow tract view, 142–144, 143f, 143t, 144f Doppler imaging, 143–144, 144f technique, 142, 143f, 143t two-dimensional anatomic imaging, 143, 144f Paravalvular aortic prosthetic regurgitation, 1105f Paravalvular mitral prosthetic regurgitation, 1102f–1104f Paravalvular mitral regurgitation, in female, 1918f–1919f Paravalvular prosthetic leaks closure of, 546–548, 549f, 550f 3D TEE monitoring of, 548, 550f, 551f 3D TEE and, 512, 513f Paravalvular regurgitation (PVR), 608–612 of prosthetic valves, 1099 vs. transvalvular regurgitation, 1106 Partial anomalous pulmonary venous connection (PAPVC), 1672 PASP. See Pulmonary artery systolic pressure (PASP) Patches, 78 Patent ductus arteriosus (PDA), 1599– 1602, 1751–1754, 1755f–1757f, 1805–1809, 1808t anatomy, 1599 aortic runoff, 1601 cardiac catheterization, 1808 chamber dimensions, 1601 closure of, 548–550, 551f–552f, 1809 direction of shunt, 1601 duct morphology, 1600–1601 subclavian origin, 1601 usual ductus, 1600 vertical duct, 1600–1601 ductus, characteristics of, 1600 echocardiography, 1599–1600 ductal view, 1599 echocardiographic views, 1599–1600 objectives, 1599 suprasternal view, 1599–1600 echocardiography for, 1805–1807 hemodynamic significance of, 1601 with left-to-right shunt, 1807

MRI/CTA, 1809 postoperative adult, 1809 pulmonary arterial pressure, 1601 stepwise evaluation for, 1599t TGA and, 1659 transesophageal echocardiography, 1808 Patent foramen ovale, 1585–1586 Patent foramen ovale (PFO), 7 closure of, 555, 557, 558f ICE imaging during, 648, 650, 650f color contrast in, 1552f Patient prosthetic mismatch (PPM), 1091–1092 Pattern correlation (PC), 88 PAU. See Penetrating aortic ulceration (PAU) PA wedge pressure (PAW), 230, 231f PCWP. See Pulmonary capillary wedge pressure (PCWP) Peak filling rate (PFR), 1157–1158 RT 3DE in, 1158f Pediatric echocardiography, birth and development of, 6 Pediatric hearts, imaging of, 285–286 Penetrating aortic ulcer (PAU), 961, 962f in elderly, 1921–1923 Penetrating chest trauma, 1972 close evaluation, 1972 hemothorax, 1972 impaling object, 1972 transesophageal echocardiogram (TEE), 1972 wounds, 1972 lower left parasternal, 1972 lower right parasternal, 1972 Percutaneous continuous flow devices, 1250–1252 Impella device, 1250, 1251f TandemHeart, 1250–1251 Percutaneous mitral balloon valvuloplasty (PMBV), 533–537, 537f–539f Percutaneous transvenous mitral commissurotomy (PTMC), 777, 790 Perfluorocarbon gases, 13 Perfusion Score Index (PSI), 423 Pericardial cysts, 1460f, 2054, 2055f Pericardial diseases, 1435–1451 acute pericarditis, 1436 anatomy of, 1435–1436 computed tomography for, 2064– 2066

Index

congenital anomalies, 1448–1449 constrictive pericarditis, 1444 Doppler flow velocity records, 1444–1448 M-mode and 2D echo, 1444 3D echocardiography, 1452–1461 echocardiographic appearance, 1435–1436 effusive-constrictive pericarditis, 1448 fibrin deposits and, 1456 M-mode and 2D echocardiography, 1437–1438 multimodality imaging of pericardium, 1450 overview, 1435 pathophysiology of, 1436 pericardial effusion, 1436–1437 pericardial tamponade, 1438–1440 Doppler flow velocity recordings, 1442–1443 echo-guided pericardiocentesis, 1443–1444 two-dimensional echo, 1440–1442 physiology of, 1436 Pericardial duplication cyst, computed tomography for, 2064 Pericardial effusion, 1045–1047, 1436– 1437 circumferential, 1500f computed tomography for, 2065, 2065f 3D transthoracic echocardiography advantages of, 1453t–1454t live/real-time, 1454f, 1455f–1456f vs. 2D transthoracic echocardiography, 1453–1456 echocardiography of M-mode, 1439f two-dimensional, 1438f epicardial fat and, 1438 exudative, 1439f tuberculous, 1458f Pericardial hydatid cyst, 1497f–1498f Pericardial masses, 1458–1461 Pericardial mesotheliomas, 1491 Pericardial metastasis, 1500f from malignant thymoma, 1459f Pericardial tamponade, 1438–1440 Doppler flow velocity records, 1442–1443 echo-guided pericardiocentesis, 1443–1444 two-dimensional echo, 1440–1442

Pericardial tumors, computed tomography for, 2065–2066 Pericardiocentesis, monitoring of, by CONTISCAN transducer, 230–233, 232f Pericarditis. See also Pericardial disease acute, 1436 chronic effusive, 1437 constrictive. See Constrictive pericarditis (CP) effusive-constrictive, 1448 etiology of, 1437t Pericardium. See also Pericardial disease functions of, 1436t multimodality imaging of, 1450 normal, 1435 Perimembranous, 1592–1593, 1592f, 1595f, 1596f inlet defect, 1592–1593 outlet defect, 1592 trabecular defect, 1593 Perimembranous inlet defect, 1592–1593 Perimembranous outlet defect, 1592 Perimembranous trabecular defect, 1593 Perimembranous ventricular septal defect, 1747f Perimembranous VSDs, 557. See also Ventricular septal defects (VSDs), closure of Peripartum cardiomyopathy, 1381–1384, 1381f–1384f definition, 1381 dobutamine echocardiography in, 1381–1384 TAPSE and, 1381 vs. DCM, 1381 in women, 1904–1905, 1904f–1905f Peripheral arterial tonometry (PAT), 467–469, 468f, 469f Peripheral artery/intra-coronary infusion of Ach, 453 Peripheral hand warming, 453 Peripheral vascular ultrasound, 663–701 carotid artery diseases and, 663–664 anterior circulation, 665–668, 667f–669f aortic arch, 664–665, 665f, 666f assessment after carotid artery endarterectomy and stenting, 688–691, 692f cardiac pathology and ultrasound findings, 693–694 2003 carotid duplex SRU consensus criteria, 684–685

cerebrovascular anatomy, 664 collateral pathways, 669–671, 670f grading carotid stenosis, 679, 682–683, 683f grading internal carotid artery stenosis, 683–684, 684t, 685f–688f intima-media thickness and carotid plaque assessment, 676–679, 678f–681f near occlusion and total occlusion of ICA, 685–688, 690f posterior circulation, 668–669, 670f scanning protocol, 671–676, 672f–675f technical aspects of carotid studies, 671 vertebral arteries, assessment of, 691–693, 694f femoral access complications by, 694–701 arterial dissection, 700 AV fistula, 699–700, 701f bleeding and hematoma, 696, 697f patient-related risk factors, 696 procedure-related risk factors, 696 pseudoaneurysm, 696–699, 698f retroperitoneal bleeding, 696 Perivalvular abscess, 1511 Permanent pacemakers/implantable cardioverter-defibrillators complications in, 1212 deleterious effects of, 1217–1218 echocardiographic findings in, 1210–1212 endocarditis and, 1214 myocardial perforation, 1215–1217 2D transesophageal echocardiography in, 1216, 1216f reported cases of, 1217t RT3DE in, 1216f overview, 1210 RV apical pacing with LV dyssynchrony, 1217–1218 thrombosis and stenosis associated with, 1215 tricuspid regurgitation, 1212–1214 lead infection associated with, 1114–1115 time course for, 1213 transthoracic echocardiography for, 1213–1214, 1213f Persistent left superior vena cava (PLSVC), 1958

I-XXIX

PET. See Positron emission tomography (PET) PFRa. See PFR difference (PFRa) PFR difference (PFRa), 1158 Phantom tumors, 737 Phased array technology, 58 Phase sensitive inversion recovery (PSIR), 2020 Phonocardiography, 25, 26f Physio ring, 582, 591f–593f Piezoelectric crystal, 55–56 PISA. See Proximal isovelocity surface area (PISA); Proximal isovelocity surface area (PISA) method PISA method, 282–283 PISA (proximal isovelocity surface area) method, 70 PLAATO device, 561–563 Plane wave ultrafast imaging, 1990, 1990f, 1991 elastography, 1991 fast graphic chips, 1991 radio frequency data, 1991 software-driven systems, 1990 spatial resolution, 1990 potential penalty, 1990 ultrafast doppler, 1990, 1991, 1991f ultrasound imaging, 1990 Plaques, 677–678, 680f, 681f Plasmacytoma, 1492f cardiac, 1490–1491, 1492f PLAX. See Parasternal long-axis (PLAX) Pleural effusion (PE), 1985 chest X-ray, 1985 computed tomography, 1985 detection, 1985 effusion, 1985 etiologies, 1985 lung appearance, 1985 minimal effusions detection, 1985 ultrasound, 1985 ultrasound images, 1985 PLFLG-AS. See Paradoxical low-flow, low-gradient aortic stenosis (PLFLG-AS) Pneumothorax (PTX), 1986 diagnosis, 1986 conditions needed, 1986 lung sliding abolition, 1986 absence, 1986 presence, 1986 nondependent condition, 1986

I-XXX


pathognomonic LUS sign, 1986 radiography, 1986 Point-of-care diagnosis, 291–296 acute care environment and, 294 battery-powered ultrasound imagers and, 291–292, 292f cardiac disorders, screening and identification of, 294 abdominal aortic aneurysm, 294–295 left ventricular dysfunction, 295 mitral valve prolapse, 295 and future directions, 296 new physical examination follow-up echocardiography, 293–294 ultrasound stethoscope, applications of, 293, 293f preparticipation screening of athletes, 295 remote areas and developing countries, imaging in, 295 traditional physical examination, 292–293, 292f training requirements, 295–296 Poiseuille, Jean, 67 Poiseuille’s law, 66, 67 Polycystic ovarian syndrome, in women, 1899 Positron emission tomography (PET), 1429 Posterior circulation, 668–669, 670f Posterior displacement of outlet septum, 1625 Posterior wall thickness (PWTd), 1118 Postsystolic contraction (PSC), 367 Posttreadmill exercise echocardiography, 8 Power Doppler, 113, 114f advantages and disadvantages of, 72 methodology, 71–72 Power Doppler harmonic imaging (PDHI), 421 Power modulation, 420 Power pulse inversion, 421 PPM. See Patient prosthetic mismatch (PPM) Pregnancy echocardiography in, 1902–1904 effect of, on HV Doppler, 303 Pre-left ventricular assist device echocardiogram, 1236t Premature ventricular contractions, and HV Doppler, 309, 309f Primary benign cardiac tumors, 1464– 1484

benign cardiac fibromas, 1480 cardiac hemangiomas, 1482–1484 cardiac lipomas, 1481–1482, 1483f cardiac myxoma, 1464–1475 cardiac rhabdomyoma, 1480–1481 Primary cardiac lymphoma, 1490 Private tags, 95 Processing technology, TEE, 103, 104f, 105f Prolonged PR interval and HV Doppler, 308, 308f and PV Doppler, 331, 331f Propagation velocity, 55, 63 in different materials, 56 PROSPECT trial, 369 Prostacyclin (PGI-2), 454 Prosthetic aortic valve abscess, 1109f–1110f, 1111f Prosthetic dehiscence, 1108f–1109f “Prosthetic pitch,” 1047 Prosthetic regurgitation paravalvular aortic, 1105f paravalvular mitral, 1102f–1104f Prosthetic valve dysfunction, 1087–1092 endocarditis, 1088–1090 obstruction, 1090–1092 patient prosthetic mismatch, 1091–1092 role of 3D TEE in operating room in, 605–617, 613f–624f regurgitation, 1087 Prosthetic valve infective endocarditis, 1047 abscess in patient with mechanical, 1047f dehiscence, 1047 “prosthetic pitch,” 1047 Prosthetic valves, 1015, 1021f–1022f, 1080–1093, 1092–1093, 1094–1112, 1948–1949 aortic position, failed homograft in, 1087f aortic prosthetic valve stenosis, 1100 aortic valve and ascending aorta, 1096 assessment of, 1082–1087 cardiac catheterization, 1092–1093 cardiac magnetic resonance imaging, 1093, 1093f cinefluoroscopy, 1092 clinical data for, 1083t computed tomography scan, 1092, 1092f 3D transesophageal echocardiography, 1100–1107

Index

color Doppler reconstruction, 1106f, 1107f–1108f paravalvular aortic prosthetic regurgitation, 1105f paravalvular mitral prosthetic regurgitation, 1102f–1104f prosthetic dehiscence, 1108f–1109f right atrial lipoma, 1096f 3D transthoracic echocardiography, 1095–1100 of homograft aortic prosthesis, 1100f, 1101f of St. Jude aortic prosthesis, 1097f, 1101f of St. Jude mitral prosthesis, 1097f, 1098f–1099f of tissue mitral prosthesis, 1100f 3D visualization, 1094–1095 2D visualization, 1111t echocardiographic evaluation of, 1084t effective orifice area of, 1084–1087 in elderly, 1948–1949, 1949f endocarditis of, 1099–1100 identification of thrombus, 1098 mitral, 1095 overview, 1080, 1094 paravalvular regurgitation, 1099 prosthetic valve dysfunction, 1087–1092 endocarditis, 1088–1090, 1089f obstruction, 1090–1092 patient prosthetic mismatch, 1091–1092 regurgitation, 1087, 1088f Ross procedure, 1086f, 1090f surgical mitral and aortic clocks, 1096 types of, 1080–1082 bioprosthetic valves, 1081–1082, 1081t, 1082t, 1088f mechanical valves, 1082, 1083t true biological valves, 1080–1081 valved canduit, 1085f–1086f Proximal isovelocity surface area (PISA) method, 82, 785, 992 for AR severity, 938–939 in mitral regurgitation, 887–888 MR severity and, 870–871 Proximal transverse aortic arch, pulse Doppler across, 1536f Pseudoaneurysms in aortic annulus, 1046f aortic valve, 1046f femoral, 696–699, 698f

Pseudosevere aortic valve stenosis, 910f PTMC. See Percutaneous transvenous mitral commissurotomy (PTMC) Pulmonary arterial hypertension (PAH), 1063, 1129 2D STE and, 372 echocardiographic prognostic predictors in, 1073t–1074t idiopathic, 1068f–1069f, 1070f pressure response to exercise, 1071t–1072t Pulmonary artery (PA) bifurcation, 1537f bifurcation and smaller, 1547f catheterization, 229–230 Pulmonary artery aneurysm, in women, 1903 Pulmonary artery hemodynamics, 1269–1273 diastolic pulmonary artery pressure, 1270–1272, 1272f mean pulmonary artery pressure, 1272, 1272f pulmonary vascular resistance, 1272–1273 systolic pulmonary artery pressure, 1270, 1270f, 1271f Pulmonary artery pressure (PAP), 1129 echocardiographic methods for, 1266t–1267t Pulmonary artery sling, 1696 Pulmonary artery systolic pressure (PASP), 1034, 1129, 1130f, 1987t Pulmonary atresia, 1033, 1581f Pulmonary capillary wedge pressure (PCWP), 1064t, 1065t, 1984 Pulmonary embolism (PE), 1067, 1985, 1986 anticoagulation treatment, 1986 color Doppler imaging, 1986 consolidated lung tissue, 1986 associated mechanical alterations, 1986 disgnosis, 1985 localization, 1985 localized multiple B-lines, 1986 lung ultrasound scan accuracy, 1985 echocardiography, 1986 leg vein compression sonography, 1986 pleuritic chest pain, 1985 pulmonary arterial flow area, 1986 sonographic findings, 1985

characteristics, 1985 ultrasonic window, 1985 Pulmonary flow acceleration time (PAcT), 1270 Pulmonary hypertension (PH), 171, 890, 1063–1079 clinical classification of, 1064t–1065t conventional echocardiography, 1063–1070 2d echocardiographic features, 1067 pulmonary hemodynamics, 1063– 1067 stress echocardiography, 1067–1070 transesophageal echocardiography, 1067 2d echocardiographic signs, indirect, 1069t diagnosis of echocardiography role in, 1075f ESC guidelines for, 1067 diagnostic algorithm in, 1073–1074 Doppler echocardiographic indices of, 1065t hemodynamic definitions of, 1064t and HV Doppler, 311, 313, 313f mitral stenosis and, 836–838 mitral valve echocardiographic scoring system, 836 M-mode echo for, 7, 7f nonconventional echocardiography, 1070–1073 real time, 3d echocardiography, 1073 strain imaging, 1072–1073 tissue Doppler imaging, 1070–1072 overview, 1063 RT 3DE of, 1170 RV systolic function in, impaired, 1069t, 1070f velocity vector imaging in, 399 Wilkins scoring system, 836–837 in women, 1901–1092 severe, 1903f Pulmonary interstitial edema, 1984, 1985 diagnosis, 1984 American College of Cardiology guidelines, 1984 B-lines, 1984 chest X-ray, 1984 chronic heart failure (HF), 1984 gray zone, 1984 limitations, 1984 pulmonary capillary wedge pressure, 1984 prognosis, 1985

I-XXXI

B-lines significance, 1985 heart failure hospitalization, 1985 persistent hemodynamic congestion, 1985 treatment, 1984, 1985 B-lines, 1985 degree of dyspnea, related to, 1985 pharmacological therapy, 1985 tailoring, 1985 pulmonary congestion, reducing of, 1984 medicines effectiveness assessment, 1984 monitoring body weight, 1984 ventricular dysfunction, 1985 Pulmonary regurgitation, 1036, 1038f, 1039f causes of, 1037f severe, 1037f Pulmonary stenosis, 171, 1032–1036 acquired causes of, 1033f congenital causes of, 1032f echocardiographic assessment of, 1034–1036, 1034f, 1035f–1036f continuous wave Doppler signal in, 1034f enlarged systolic frame, 1036f midtransesophageal view, 1036f patient with tetralogy of fallout, 1035f transpulmonary valve velocity, 1035f etiology, 1032 grades of, 1034 normal pulmonary valve area in, 1034 pathology, 1032 pulmonary atresia, 1033 secondary anatomic changes in, 1033 types of, 1033 Pulmonary thrombo disease, 1976 arotic dissection, 1976f dilatation, 1976 echocardiographic evaluation, 1976 Echogenic structure, 1977f false lumen, 1977f post diagnosis, 1976 pulmonary hypertension, 1977f pulmonary thrombo-embolic, 1976 pulmonary thromboembolism, 1976, 1976f right ventricle/left ventricle end diastolic dimension, 1976 true lumen, 1977f ventricular dysfunction, 1976 Pulmonary valve, 1031–1041

I-XXXII


in adults, 1816–1818 cardiac catheterization, 1817 MRI/CTA for, 1817 postoperative adult, 1818 surgical treatment for, 1817–1818 cardiac CT scans, 1040 cardiac MRI, 1040 catheterization, 1040 congenital diseases in newborns, incidence of, 1032t echocardiographic evaluation, 1037–1038 effective regurgitant orifice area, 1038 epidemiology, 1031–1032 parasternal short-axis view of, 1034f postpulmonary valve surgery, 1039–1040 allograft replacement, 1040 pulmonary regurgitation, 1036, 1038f causes of, 1037f severe, 1037f pulmonary stenosis, 1032–1036 acquired causes of, 1033f congenital causes of, 1032f echocardiographic assessment of, 1034–1036, 1034f, 1035f–1036f etiology, 1032 grades of, 1034 normal pulmonary valve area in, 1034 pathology, 1032 pulmonary atresia, 1033 secondary anatomic changes in, 1033 types of, 1033 pulse Doppler across, 1536f Ross procedure, 1038–1039 artificial conduits in, 1039 pulmonary homograft, 1038, 1039f right ventricular outflow tract, 1038 Pulmonary valve fibroelastoma, 1478f Pulmonary vascular resistance (PVR), 1063, 1065t, 1066, 1272–1273 Pulmonary vein ablation cardiac computed tomography for, 2054–2057 computed tomography for, 2054– 2057 Pulmonary vein isolation, for atrial fibrillation, 566, 568–569, 569f, 570f Pulmonary veins (PV), 1670–1684, 1963 ablative therapies, 1963 abnormalities, 1963 additional ablation, 1963

anatomy, 1963 delineating, 1963 anatomy of, 325 anomalies of, 1672–1673 abnormal number of pulmonary veins, 1672 anomalous pulmonary venous return, 1672–1673 blood flow in aging and, 329–330, 330f factors affecting, 329–331 loading conditions and, 330–331 physiology of, 325–327, 326, 328f respiration and, 329 cardiac MR, 1963 color contrast in, 1552f color Doppler of, 1533f CT angiography, 1963 disease states, and PV blood flow atrial fibrillation, 333, 333f atrial flutter, 333, 333f atrial septal defect (ASD), 342, 342f atrioventricular dissociation, 331–332, 332f cardiac tamponade, 341 conduction disorders, 331 constrictive pericarditis, 340–341, 340f, 341f junctional rhythm, 333, 334f left ventricular end-diastolic pressure, assessment of, 334–335, 334f, 335f mean left atrial pressure, assessment of, 335, 335f mitral regurgitation, 336–338, 337f, 338f mitral stenosis, 338–339, 339f myocardial relaxation pattern, impaired, 335–336 paced rhythm, 334, 334f premature ventricular contractions, 332, 332f prolonged PR interval, 331, 331f pseudonormal filling pattern, 336 pulmonary vein stenosis, 342, 342f rate and rhythm disorders, 332–334 restrictive cardiomyopathy, 339–340, 340f restrictive filling pattern, 336, 337f short PR interval, 331, 331f sinus bradycardia, 332, 333f sinus tachycardia, 332, 332f flaring degree, 1964 floating thrombus, 1965f

Index

flow pattern, 1964 atrial reversal, 1964 diastolic dysfunction, 1964 diastolic forward flow, 1964 mitral regurgitation, 1964 systolic forward flow, 1964 A Flutter, 1963 imaging, 1963 imaging of, 325–329 technical considerations in, 327, 329, 329t transesophageal echocardiography, 327 transthoracic echocardiography, 327 isolation, 1963 left inferior, 1963 left upper, 1963f limitations and technical pitfalls, 342, 342f localization, 1964 lower, 1963f macro-reentrant tachycardia, 1963 midesophageal, 1963 level, 1963f probe, 1963 morphological features, 1963 normal flow pattern of, 1670–1672 ostium, 1964 peak diastolic velocity, 1965f pulmonary hypertension, 1964 pulse Doppler of, 1533f right middle, 1965f to right-sided left atrium, 1546f right upper, 1963f caval view, 1964 spectral Doppler of, 325–345 artifacts, 343–345, 344f–345f differential diagnosis for abnormal PV flow patterns, 345, 345f limitations and technical pitfalls, 342–343, 344f stenosis, 1965f development, 1964 systemic venous anomalies, 1678– 1684 systolic forward flow, 1964 thoracic aorta,descending, 1963 total anomalous pulmonary venous connection, 1673–1678, 1673f, 1674f–1675f anomalous drainage of, 1676 diagnosis steps in, 1673–1676 echocardiographic goals, 1673 features of, 1673

pulmonary vein stenosis and, 1678 pulmonary venous confluence, 1673–1675 septum primum malposition defect and, 1676–1678, 1677f Pulmonary vein stenosis and PV Doppler, 342, 342f with TAPVC, 1678 Pulmonary venous confluence (PVC), 1673–1675, 1674f orientation and site of drainage of, 1674–1675 Pulmonary venous flow, MR severity and, 869 Pulmonic valve 3D echo of, 522–523, 522f, 523f ventricular assist devices and, 1232 Pulmonic valve disease, 3DE assessment of, 284, 284f, 285f Pulsed Doppler, 63–64. See also Spectral Doppler Pulsed wave Doppler advantages and disadvantages of, 69 and aliasing, 70, 70f methodology, 69–70, 69f Pulse inversion, 420 Pulse pressure (PP), 467 Pulse repetition frequency (PRF), 63, 69, 736 Pulse wave velocity (PWV) analysis, 466–467, 466f, 467f PVR. See Pulmonary vascular resistance (PVR) PWTd. See Posterior wall thickness (PWTd) Pyramidal imaging, 241 PZT (lead zirconate titanate) ceramics, 102, 103f

Q QLab, 385,514 Quadrature detector, 66 Quadricuspid aortic valve, 1620, 1620f in female, 1915f Quantification techniques in echocardiography, noninvasive, 705–729 aortic valve assessment, 727–728, 728f 3DE quantification tools, clinical applications of, 721–723 left ventricle global and regional function, 722

left ventricle mass, 722, 722f left ventricle shape analysis, 722–723, 723f fluid mechanics algorithms and particle imaging, 720–721, 721f future outlook, 728–729, 729f global strain, 712–714, 712f–715f goal of, 706 heart chamber segmentation algorithms, 706–707, 707f limitations of speckle tracking echocardiography, 720 mitral valve assessment, 725–727, 726f–728f parametric display, 708–711, 709f–711f regional strain, 714–715, 715f, 716f right ventricular quantification, 723–725, 723f–726f rotation, twist, and torsion, 717–720, 719f segmental/regional analysis of left ventricle, 707–708, 708f, 709f strain quantification and speckle tracking algorithms, 711–712 three-dimensional speckle tracking and strain, 715, 717, 717f–719f Quantitative gated single-photon emission computed tomography (QGSPECT), 271

R RABT (red away blue toward), 64 Radial strain, 362, 363f, 389 Range ambiguity, 736. See also Artifacts RAP. See Right atrial pressure (RAP) Rashkind procedure, 531 RBBB. See Right bundle branch block (RBBB) RCM. See Restrictive cardiomyopathy (RCM) Reactive hyperemic index (RHI), 467–468 Reactive oxygen species (ROS), 454 Real time, three-dimensional TEE (RT3DTEE) probe, 101–102, 101f, 102f Real time 3D echo (RT3DE), 1142–1143 Real time (RT) 3D mode, 269 Real time (RT) 3D TTE, 74 Real time/live 3D echocardiography, 241 Real time myocardial perfusion echocardiography (RTMPE), 444–445

I-XXXIII

Real time three-dimensional echocardiography (RT3DE) future perspectives of, 1728 left ventricular ejection fraction, 1722–1723 analysis in children, 1723, 1724t meta-analysis, 1723 for left ventricular mass, 1723 left ventricular volumes, 1722–1723 in adults with congenital heart disease, 1722 analysis in children, 1723, 1724t correlation with CMR, 1722 meta-analysis, 1723 overview, 1721–1722 regional wall motion and synchrony, 1726–1727 right ventricular ejection fraction, 1723–1725 analysis in children, 1724–1725 meta-analysis of, 1725 right ventricular volumes, 1723–1725 analysis in children, 1724–1725 meta-analysis of, 1725 single ventricular ejection fraction, 1725–1726 single ventricular mass, 1725–1726 single ventricular volumes, 1725– 1726 strain analysis by, 1727–1728 Receiver, 60 Red blood cells (RBCs), 416 Reflection artifacts, 62, 62f Regional strain, 714–715, 715f, 716f Regional wall motion and synchrony, RT3DE of, 1726–1727 Region of interest, 71 Registered Cardiac Sonographer (RCS), 754 Registered Cardiovascular Invasive Specialist (RCIS), 754 Registered Diagnostic Cardiac Sonographer (RDCS), 754 Registered Vascular Specialist (RVS), 754 Registered Vascular Technologist (RVT), 754 Regurgitant jet, spectral strength of, 811t Regurgitant volume (RV), 1376 Reid, John, 6 Remote ventricular septal defect, 1648 Renal disease, 1870–1872 Reperfusion, speckle-tracking echocardiography, 1302 Resolution, 58, 655

I-XXXIV Comprehensive Textbook of Echocardiography axial, 59, 59f frame rate, 59, 60f lateral, 59, 59f line density, 60 Respiration, effect of on hepatic venous flow, 302–303, 303f, 306, 307f on pulmonary venous flow, 329 Resting myocardial perfusion abnormality, 2044f Restrictive cardiomyopathy (RCM), 395, 1369, 1397–1404 amyloid cardiomyopathy, 1398–1401, 1399f–1400f contrast echocardiography, 1402 Doppler echocardiography, 1398 endomyocardial fibrosis, 1402–1404, 1404f Fabry disease, 1401–1402, 1401f and HV Doppler, 315, 315f hypereosinophilic cardiomyopathy, 1402 and PV Doppler, 339–340, 340f transesophageal echocardiography, 1402 transthoracic echocardiography, 1402 Retroaortic innominate vein, 1682, 1682f Retrograde aortic arch flow, 1551f Retrograde ductal arch (DuAr), 1554f Retroperitoneal bleeding, 696 Reverberation artifacts, 62, 62f, 734–735, 735f. See also Artifacts transesophageal echocardiography and, 107, 109–110, 109f Reynolds, Osborne, 67 Reynold’s number, 66, 67 Rhabdomyosarcomas, 1486–1488 Rheumatic heart disease (RHD), 1859 ARF and, 774 chronic, 775 morphological features of, 777t tricuspid stenosis and, 1006f WHF echocardiographic criteria for, 775, 776t Rheumatic mitral regurgitation, 863 Rheumatic mitral stenosis, 533–537, 537f–539f in female, 1890f–1891f, 1893f–1984f Rheumatic valvular heart disease, 898 Rheumatoid arthritis (RA), 1868 Right aortic arch, 1690–1691 Right atrial lipoma, 1096f Right atrial myxomas, 1470f, 1473

Right atrial pressure (RAP), 1063, 1065t, 1143–1144, 1264–1269 Doppler and tissue Doppler imaging, 1268–1269, 1269f echocardiographic methods for, 1265t estimation of, 1066t IVC parameters, 1264–1266, 1266f size and collapsibility, 1266 RA dimensions, 1269, 1269f systemic venous flow, 1268, 1268f Right atrial thrombus, 1504f Right atrium–right ventricle (RA–RV), 1958 Right atrium thrombus, 1505f Right bundle branch block (RBBB), 1726 Right coronary artery fistula, 1782–1783 Right heart failure, and cardiac motion, 1204 Right isomerism, 1577 Right parasternal approach, of three dimensional echocardiography, 246, 248, 259f–266f Right pulmonary artery (RPA), short axis of, 1536f Right-sided infective endocarditis, 1047–1049 transesophageal approach, 1048f type of patient with, 1048–1049 Right upper pulmonary vein (RUPV), 327, 328f Right ventricle, 1198 cardiac motion and, 1198 double outlet, 1547f evaluation of, 1235t failure, 1247f ventricular assist devices and, 1233–1234 Right ventricle, 3D quantitation of, 1165–1170 anatomic considerations, 1165–1166 conventional approaches, 1165–1166 2D echocardiography, 1166f 3D reconstruction approaches, previous, 1167 global function, 1166 longitudinal contraction, 1166 retrosternal location of, 1166 RT 3DE approach to, 1167–1170 apical rotation method, 1168f automatic boundary tracking algorithm, 1169f of congenital heart disease, 1170 data acquisition, 1167f

Index

disc summation method, 1169f of pulmonary hypertension, 1170 second-generation, 1167–1168 transverse shortening and, 1166 Right ventricle, evaluation of, 1134–1148 “apex-forming,” 1136 cardiac magnetic resonance imaging, 1136f, 1144–1145, 1144f cardiovascular computed tomography, 1145 contractile function, 1140–1141 Doppler echocardiography, 1139– 1141 continuous wave Doppler spectral display, 1139 conventional doppler, 1139–1140 pulsed wave Doppler spectral display, 1140, 1142f tissue doppler, 1140–1141, 1141f echocardiography, 1136 M-mode, 1136–1138 three-dimensional, 1142–1143 transesophageal, 1143 two-dimensional, 1138–1139, 1139f, 1140f, 1141f echo windows for, 1137f gadolinium contrast in, 1145 geometry of, 1135f hemodynamics, 1143–1144 HV systolic filling fraction, 1144 right atrial pressure, 1143–1144 morphology, 1135–1136 regional RV wall motion, 1136 right ventricular outflow tract, 1135 RV systolic function, 1135–1136 myofibrillar arrangement of, 1136– 1137 overview, 1134–1135 evaluation of, 1134–1148 real time 3D echo, 1142–1143 Simpson’s method of discs for, 1140f “triangle of dysplasia,” 1135, 1135f two-dimensional strain (speckle tracking), 1141–1142, 1142f volume/body surface area, 1143t Right ventricle fractional area change (RVFAC), 1071f Right ventricular diastolic dysfunction, 1644f and HV Doppler, 313–315, 315f Right ventricular dysfunction ICM/NICM and, 1422 mild residual, 1242f

Right ventricular ejection fraction (RVEF), 381, 1137–1138 global function of RV, 1166 Right ventricular end-diastolic pressure (RVEDP), 309–310, 310f Right ventricular end-diastolic volume (RVEDV), 1168 Right ventricular endomyocardial biopsy, 571 Right ventricular fibroma, 1481f Right ventricular function, TD assessment of, 354, 356f–357f Right ventricular hemangioma, 1486f Right ventricular lipoma, 1483f Right ventricular myxomas, 1471f–1472f, 1473–1474, 1473f Right ventricular noncompaction, 1389f–1391f isolated, 1392f Right ventricular outflow tract (RVOT), 1135, 1138 flow velocity envelope, 1068f outcomes of allograft conduits for, 1039 pulmonary hypertension and, 1066–1067, 1067f Ross procedure and, 1038 Right ventricular quantification, 723–725, 723f–726f Right ventricular sarcoma, 1487f Right ventricular stroke volume (RVSV), 1167 Right ventricular systolic dysfunction, 313, 314f Right ventricular thrombus, 1506f Right ventricular wall (RVW), 1971t RIMP. See RV index of myocardial performance (RIMP) Ring dehiscence, 605–606 Rotatable transesophageal echo (TEE) probe, 100, 100f, 101f Rotation (cardiac motion), 1183 RSOV. See Ruptured sinus of Valsalva (RSOV) RT3DE. See Real time 3D echo (RT3DE) Ruptured sinus of Valsalva (RSOV), 1632 RVEDV. See Right ventricular end diastolic volume (RVEDV) RVEF. See Right ventricular ejection fraction (RVEF) RVFAC. See Right ventricle fractional area change (RVFAC) RV FAC. See RV fractional area change (RV FAC)

RV fractional area change (RV FAC), 1139 RVFS. See RVOT fractional shortening (RVFS) RV index of myocardial performance (RIMP), 1141 RVOT. See Right ventricular outflow tract (RVOT) RVOT fractional shortening (RVFS), 1138 RV regional isovolumic relaxation time (RVrIVRT), 1268 RVrIVRT. See RV regional isovolumic relaxation time (RVrIVRT) RVSV. See Right ventricular stroke volume (RVSV)

S Sacrococcygeal teratoma, 1530 Saline contrast, 12–13 Saline contrast chocardiography, 435, 436f SAM. See Systolic anterior motion (SAM) Sapien valve, balloon expandable, 541–543 Sarcoidosis, 1405, 1405f, 1876–1879 Sarcomas, 1484–1488, 2054 right ventricular, 1487f SAVR. See Surgical aortic valve replacement (SAVR) Scan line, 77 Scanners, trends, 1991–1993 acoustic structure quantification, liver, 1992, 1992f advantage, 1992 B-mode signal analysis, 1992 cable-free transducer systems, 1992 development of, 1992 capacitance micro-machined ultrasound transducer, 1992 complete cross-sectional display computed tomography, 1993 magnetic resonance, advantages of, 1993 contrast-enhanced ultrasound, 1991, 1992 crystal piezoelectric materials, 1991 electrostatic loudspeaker, 1992 fusion imaging, 1993f Lead zirconate titrate, 1992 miniaturization, 1991 scanner user interfaces, 1993 semiconductors, 1992 smartphone ultrasound system, 1991, 1991f

I-XXXV

software-driven scanners, 1991 symmetrical effect, 1992 tissue characterization conference, 1992 transesophageal echocardiography live/real time three/four dimensional, 1992, 1992f ultrasound system, 1991 SCD. See Sudden cardiac death (SCD) Sclerosing mediastinitis, 1515f–1517f Screen, 60 Secondary cardiac tumors, 1492–1500 carcinoid heart disease, 1500 malignant melanoma, 1500 Sector angle, and frame rate, 59, 60f Sector probe, 58, 58f Secundum ASD, 1734–1742 device embolization in, 1739 3D TEE in, 1738–1739, 1739f, 1740f–1742f repair of, 1734–1736 Semilunar valves, short axis of, 1536f Septal aneurysms, 182 Septal wall thickness at diastole (SWTd), 1118 Septic cardiomyopathy, 1405–1407, 1406f echocardiographic features of, 11406–407 Septum (ventricular), 1194–1198, 1205f echocardiographic pattern of, 1196f endocardial and epicardial fibers, 1195f fiber orientation of, 1195f “septal line,” 1194 ultrasonic crystal tracings, 1197f Septum primum malposition defect TAPVC and, 1676–1678, 1677f Serial evaluation, of patients with 3DE, 1164–1165 Shah, Pravin, 11 Shear rate, 452 Shear stress, 452–454, 452f–454f, 455. See also Endothelial dysfunction Short PR interval and HV Doppler, 307, 308f and PV Doppler, 331, 331f Short-tau-inversion-recovery (STIR), 2020 Short-term circulatory support devices, 1226–1227 Abiomed AB5000, 1227 Impella catheter-based assist device, 1227 TandemHeart system, 1227

I-XXXVI Comprehensive Textbook of Echocardiography Thoratec CentriMag system, 1227 Thoratec paracorporeal ventricular assist device, 1227 Shunt lesions aortopulmonary window, 1602–1603 atrial septal defects, 1585–1591 features of, 1582–1585 Gerbode defect, 1603, 1603f, 1604f ventricular septal defect, 1591–1599 Shunt lesions, in adults, 1798–1813 atrial septal defects, 1799–1802, 1801t cardiac catheterization, 1802 closure of, 1802 contrast echocardiography, 1801– 1802 echocardiography, 1799 exercise testing, 1802 MRI/CTA for, 1802 postoperative adult in, 1802 transesophageal echocardiography, 1800–1801, 1800f types of, 1799–1800, 1799f atrioventricular septal defect, 1809–1810 echocardiography, 1809–1810 postoperative adult, 1810 coronary artery fistula, 1812–1813 patent ductus arteriosus, 1805–1809, 1808t cardiac catheterization, 1808 closure of, 1809 echocardiography for, 1805–1807 with left-to-right shunt, 1807 MRI/CTA, 1809 postoperative adult, 1809 transesophageal echocardiography, 1808 patent foramen ovale, 1798–1799 persistent left superior vena cava, 1810–1811 echocardiography, 1810 MRI/CTA, 1810–1811 postoperative adult, 1811 sinus of Valsalva aneurysm, 1811– 1812 ventricular septal defects, 1802–1805, 1806t cardiac catheterization, 1805 closure of, 1805 echocardiography, 1804–1805 inlet, 1804 locations of, 1804f membranous, 1803 MRI/CTA for, 1805

muscular, 1804 postoperative adult, 1805 supracristal, 1803 “venturi effect,” 1803f Shunt lesions/septal defects, 1733–1747 atrial septal defects, 1734 atrioventricular septal defectsts, 1746–1747 secundum ASD, 1734–1742 sinus venosus ASD, 1742–1743 unroofed coronary sinus, 1743 ventricular septal defects, 1743–1746 Sickle cell disease, three-dimensional speckle tracking and, 376t Side lobe artifacts, 62–63, 63f, 736. See also Artifacts transesophageal echocardiography and, 107, 108f Sigmoid septum, of elderly, 167 Single element transducers, 76, 76f Single-photon emission computed tomography (SPECT), 1425–1427 Single plane transesophageal echo (TEE) probe, 99, 99f Single ventricle, velocity vector imaging in, 392–394 Sinotubular (ST) junction, 168, 1621 Sinus bradycardia and HV Doppler, 306, 307f and PV Doppler, 332, 333f Sinus of Valsalva aneurysm, 1630–1632, 1631f, 1784 in adults, 1811–1812 aortic regurgitation and, 1631 associated anomalies, 1631–1632 echocardiographic evaluation of, 1630–1631 hypoplastic left heart syndrome, 1784 right ventricular outflow obstruction and, 1784 ruptured right, 1784f–1785f VSD and, 1631 Sinus tachycardia and HV Doppler, 306, 307f and PV Doppler, 332, 332f Sinus venosus ASD (SVASD), 1586, 1742–1743, 1743f Sinus venous defect, 1800 Sjogren’s syndrome, 1545 SLE. See Systemic lupus erythematosus (SLE) Slicing methods, 79 Smearing, 59 Society of Cardiovascular Anesthesiologists (SCA), 638

Index

Sonar system, development of, 4 Sonic reflector, good, properties of, 65 SonoHeart, 292f Sonovue, 417, 418t. See also Contrast echocardiography Sound velocity, effect of, 107, 107f, 107t, 108t Sound waves, 55–56, 56f SPAMM. See Spatial modulation of magnetization (SPAMM) SPAP. See Systolic pulmonary arterial pressure (SPAP); Systolic pulmonary artery pressure (SPAP) SPARC. See Stroke Prevention: Assessment of Risk in a Community (SPARC) study Spark gap position-locating approach, 14 Spatial and temporal resolution, 3D imaging and, 80, 80f Spatial modulation of magnetization (SPAMM), 2000 Spatial resolution, 55 Spatiotemporal image correlation (STIC), 285–286, 1550 Speckle tracking acquisition, 87–98 arrhythmias and, 98 2D speckle tracking, limitation of, 92 gain setting, 97 M-mode, 87–88, 88f multiview monitoring during live acquisition, 97, 97f multiview orientation, 97, 98f patient breath-hold, 98 R–R interval, 91 standardization, 91–92 standard views, 91 three-dimensional acquisition, 92, 94f–95f frequency, 95 modes, 96, 97f one-beat acquisition, 96 raw data storage, 95 scan range/volume width, 96 triggered full volume, 96, 97f volume rate, 96 wall motion tracking, 92, 95 versus tissue doppler imaging, 92 two-dimensional speckle tracking, 88, 88f acquisition considerations, 88 depth, 89 dynamic range, 90 frame rate, 88–89, 89f gain level, 89, 89f

high frame rate, 89 imaging mode, 90, 90f lateral gain, 89–90 raw data format, 90 scan range, 89 two-dimensional frequency, 90 Speckle-tracking echocardiography (STE), 360–376, 382, 1302–1304. See also Velocity vector imaging (VVI) cardiac muscular anatomy, 360–361, 361f image acquisition and processing, 367 limitations of, 374– 375 myocardial infarction, 1302 myocardial ischemia, 1302 myocardial viability, 1302–1303 reperfusion, 1302 strain and, 362–365, 362t, 363f three-dimensional, 372–373, 373f, 374f area strain measurement and, 373, 375, 375f, 375t clinical applications of, 373–374, 376t and tissue Doppler imaging, 360, 361t two-dimensional, 365–367, 365t, 366t cardiac transplantation and, 371 cardiomyopathies and, 369–371 chemotherapy cardiotoxicity and, 371–372 clinical application of, 367–372, 368t congenital heart disease and, 372 coronary artery disease and, 367 CRT for heart failure and, 369 right ventricular function and, 372 rotational dynamics, role of, 372, 372f valvular heart diseases and, 371 SPECT. See Single-photon emission computed tomography (SPECT) Spectral broadening, 68 Spectral Doppler, 66, 112–113, 113f transthoracic echocardiogram, 136–137, 137f “Splenic syndromes,” 1704 Squatting stress echocardiography, 1323–1327, 1324–1326 acute LV remodeling on, 1325 advantages of, 1326 chronic obstructive pulmonary disease, 1323 coronary artery disease, 1323 electrocardiography (ECG), 1323 end-systolic frames in, 1324f

limitations of, 1326 LV function and, 1324f mechanism of, 1325 overview, 1323 protocol, 1324 results/observations, 1324–1325 vs. dobutamine stress echocardiography, 1325, 1326t wall motion abnormalities, 1323 left ventricular, 1324–1325 mechanism of, 1325 St. Jude aortic valve, 1085f St. Jude bileaflet mitral valve, 1092f Stanfard classification, 1974 apical, 1976t ascending aorta, 1974 diastolic collapse, 1976 dissections, 1974 esophagus, 1976 left parasternal, 1976t lumen, 1976 mitral valve, 1975f pressure Half-time, 1975t systolic expansion, 1976 transesophageal probe, 1976 transthoracic views, 1976t visualization, 1974 Stanford type A aortic dissection, 935, 936f Staphylococcus aureus, 1048 STARFlex occluder, 557 Starr–Edward valve, 1085f State Food and Drug Administration (SFDA),China, 110 State-of-the-art, 1180–1181 composite of, 1181–1183 HVMB model, 1181 muscle contraction, asynchronous, 1181 Statins, 450 Steady-state free precession (SSFP), 2020 for aortic regurgitation, 2010 Stenosis of pulmonary outflow, 1647– 1648 aortic outflow obstruction, 1647 remote ventricular septal defect, 1648 ventricular septal defect, restriction of, 1647f, 1648 Stenotic aortic valve, morphology, 1619–1620 STIC. See Spatiotemporal image correlation (STIC) Stiffness index (SI), 465, 467

I-XXXVII

Strain calculation of, 362 imaging, 360 normal, 385, 389 normal rotation and torsion values, 364t normal values for, in normal adults, 364t peak, 365 physics of, 385, 389, 389f rate, 362 shear, 385, 389 types of, 362, 362t, 363f Streptococcus viridans, 1054 Stress (Takotsubo) cardiomyopathy three-dimensional speckle tracking and, 376t Stress echocardiography, 226–227, 1306–1322 cardiac event rate as function of, 1315f cost-effectiveness of, 1317–1318 Doppler hemodynamics with, 1318–1319 aortic valve disease, 1318 dynamic pulmonary hypertension, 1318–1319, 1319f hypertrophic cardiomyopathy, 1318 latent diastolic dysfunction, 1318 mitral valve disease, 1318 fundamentals of, 1306–1307 future directions for, 1319 impact on patient outcome, 1317 interpretation of, 1309–1319 diagnostic accuracy to detect CAD, 1310, 1313t transient ischemic LV cavity dilatation, 1315 “warranty time,” 1317 myocardial infarction vs. cardiac death by, prediction of, 1311–1315 myocardial perfusion and, 1319 overview, 1306 predictors of risk, 1314t prognostic value of, 1316t risk stratification and prognosis, 1310–1315, 1314f left atrial size in, role of, 1317 myocardial wall motion abnormality, 1311 RV wall motion abnormalities in, role of, 1315 safety of, 1308–1309

I-XXXVIII Comprehensive Textbook of Echocardiography three dimensional, 1319 training in, 757 types of, 1307–1309 contrast echocardiography, 1308 dobutamine stress echocardiography, 1307, 1308f exercise echocardiography, 1307, 1308f vasodilator stress echocardiography, 1307–1308 vs. nuclear SPECT imaging, 1313t Stress testing, three-dimensional echocardiography for, 274, 274f Stroke distance (SD), 1280, 1281f Stroke Prevention: Assessment of Risk in a Community (SPARC) study, 1921 Stroke volume (SV), 1280, 1281f in DCM, 1375 in dilated cardiomyopathy, 1375 Structural heart disease, in women, 1888–1889 mitral valve calcification, 1889 mitral valve prolapse, 1888, 1888f–1889f mitral valve stenosis, 1888–1889 Subaortic stenosis, 1770 in adults, 1824–1825 Subcostal approach, of three dimensional echocardiography, 244, 256f–255f Subcostal window, TTE color and spectral Doppler imaging, 158–159 four-chamber view, 155, 156f, 156t, 157f great vessel imaging, 157–158, 158f, 159f abdominal aorta, 158, 159f hepatic vein, 158, 158f inferior vena cava, 158, 158f short-axis views, 157, 157f Subendocardial muscle, 1198–1200, 1199f, 1200f Subvalvular aortic stenosis, 1624–1626, 1624f aortic insufficiency and, 1626 cause of, 1624 diffuse tunnel obstruction and, 1626 discrete subvalvular, 1626 echocardiographic evaluation of, 1624 fibromuscular collar in, 1625 fixed subaortic obstruction, 1624– 1625

membranous subaortic stenosis, 1625 posterior displacement of outlet septum in, 1625 Subvalvular infundibular stenosis, 1033, 1035f, 1036f Sudden cardiac death (SCD), 1348 Summed difference score (SDS), 1158 vs. WMS difference, 1159f, 1159t Summing, 77 Superior vena cava (SVC), 1140 anomalies of, 1678–1682 absent right, 1680 aneurysm of, 1682 clinical significance of, 1680–1681 defect in wall of coronary sinus, 1679–1680 left superior vena cava to coronary sinus, 1679–1680 left superior vena cava to left atrium, 1680 persistent left, 1678–1679 right superior vena cava to left atrium, 1681, 1681f heterotaxy syndrome and, 1705 normal spectral Doppler of, 304, 304f Supraclavicular approach, of three dimensional echocardiography, 244, 258f–259f Suprasternal approach, of three dimensional echocardiography, 244, 257f Supravalvular aortic stenosis, 1626–1628, 1626f in adults, 1825–1826 aortic valve anomalies, 1627 branch pulmonary arteries in, 1628, 1628f coronary artery abnormalities, 1628 morphology, 1627 Supravalvular stenosis, 1033 Supraventricular tachycardia (SVT), 1542, 1957 Surface rendering, 79, 79f Surgical aortic valve replacement (SAVR), 540–541 in aortic stenosis, 926–927 in LFLG-AS with low ejection fraction, 927 PLFLG-AS and, 922 in PLFLG-AS with normal ejection fraction, 927 Suture-less valves, 606 SVC. See Superior vena cava (SVC)

Index

Swirling, 433, 434f Swiss cheese defects, 1594 SWTd. See Septal wall thickness at diastole (SWTd) Systemic diseases, 1867–1885 amyloidosis, 1872–1874, 1873f–1874f carcinoid tumors, 1874–1875 Chagas disease, 1875–1876, 1877f–1878f echocardiography in, 1867–1885 hypereosinophilic syndrome, 1868–1869, 1870 nutritional deficiency, 1880 overview, 1867 renal disease, 1870–1872 rheumatoid arthritis, 1868 sarcoidosis, 1876–1879 systemic lupus erythematosus, 1867–1868 systemic sclerosis, 1869–1870 thyroid disorders, 1879–1880 Systemic hypertension, in female, 1910f Systemic lupus erythematosus (SLE), 1545, 1867–1868 in female, 1912f Systemic pulmonary shunts (QP/QS), 1280 Systemic sclerosis, 1869–1870 Systemic veins, anomalies of, 1678–1684 classification of, 1678 coronary sinus, abnormalities of, 1683 decompressive venous channels, 1684 inferior vena cava, abnormalities of, 1682–1683 bilateral, 1683 inferior vena cava interruption, 1682–1683 inferior vena cava to left atrium, 1683 retroaortic innominate vein, 1682, 1682f superior vena cava, 1678–1682 absent right, 1680 aneurysm of, 1682 clinical significance of, 1680–1681 defect in wall of coronary sinus, 1679–1680 left superior vena cava to coronary sinus, 1679–1680 left superior vena cava to left atrium, 1680 persistent left, 1678–1679 right superior vena cava to left atrium, 1681, 1681f

total anomalous systemic venous drainage, 1684 venous valves, 1683–1684 Systolic abnormalities, of tricuspid valve, 986 Systolic anterior motion (SAM), 1348 echocardiographic evaluation of, 1351–1352, 1352f mitral-septal contact, 1359f of mitral valve, 1350–1354, 1350f, 1359f pathophysiology of, 1353 Systolic blood pressure (BP), pseudonormalization of, 911 Systolic dysfunction, and HCM, 1356– 1358 Systolic dyssynchrony index (SDI), 373, 1726 Systolic function in dilated cardiomyopathy, 1371 in ICM/NICM, 1419 Systolic myocardial dysfunction, 1131f Systolic pulmonary artery pressure (SPAP), 1063, 1065t, 1066, 1067, 1270, 1270f, 1271f

T TAA. See Thoracic aortic aneurysm (TAA) Tachycardia-induced cardiomyopathy, 1388, 1395f Takotsubo cardiomyopathy, 1388, 1394f in women, 1899–1900 vector velocity imaging, 1900 TandemHeart device, 1225f, 1227, 1250–1251 TAPSE. See Tricuspid annular plane systolic excursion (TAPSE) in peripartum cardiomyopathy, 1381 TAPVC. See Total anomalous pulmonary venous connection (TAPVC) TAPVR. See Total anomalous pulmonary venous return (TAPVR) Taussig–Bing anomaly, 1647 Tei's index, 1120, 1120f, 1419 Temporal tap, 674, 675f Tenting area, 1422, 1423f Tetralogy of fallot (TOF), 1763 with absent pulmonary valve, 1637, 1637f in adults, 1829–1835 cardiac catheterization, 1834–1835 echocardiography, 1830–1832 MRI/CT for, 1835

postoperative adult, 1835 postoperative adult, surgery in, 1835 stress echocardiography, 1832–1834 aortic regurgitation in, 1641, 1641f cardiac catheterization, indications for, 1641 computed tomography for, 2062, 2063f echocardiographic measurements in, 1640–1641, 1640f Hoffman's variant, 1635f, 1636f postoperative evaluation of, 1641– 1644, 1642f with pulmonary stenosis, 1633 velocity vector imaging in, 391–392 Thebesian valve, 1503 Thermal index (TI), 111 Thoracic aortic aneurysm (TAA), 1934–1937 in Marfan syndrome, 1936 natural history of, factors impacts, 1937 Thoracic cage artifacts, 433–434, 434f Thoratec CentriMag system, 1127 Thoratec HeartMate II, 1223f Thoratec paracorporeal ventricular assist device, 1227 Three-dimensional echocardiographic guidance of percutaneous procedures, 531–571. See also Catheter-based transcutaneous interventional procedures Three-dimensional echocardiography (3DE), 14–18, 240–267, 705 advantages/disadvantages of, 262, 267 apical approach, 244, 254f, 255f artifacts in, 736–737. See also Artifacts basics of, 74–85 beam forming, 77–78 color Doppler imaging, 248, 254–255, 266f evolution of, 74–75, 75f examination protocol, 241–244, 242f–243f image quality, limitations in aperture, 80 artifacts, 80–81 gating, 80 spatial and temporal resolution, 80, 80f left parasternal approach, 244, 245f–254f

I-XXXIX

multibeat acquisition in, 74–75, 75f in operating room, 577–634 aortic valve disease, 582–588 cardiac masses, 617–627 limitations of 3D TEE and future directions, 628–629 mitral valve disease, 577–582 native valve endocarditis, 597–604 prosthetic valve dysfunction, 605–617 tricuspid valve disease, 589–590, 593–597 quantification, 81–85 left ventricular, 82–85, 84f mitral valve, 81–82, 82f, 83f rendering in, 78, 79f 2D tomographic slices, 79–80 surface rendering, 79 volume rendering, 78–79, 79f right parasternal approach, 246, 248, 259f–266f strengths of, 81 subcostal approach, 244, 256f–255f supraclavicular approach, 244, 258f–259f suprasternal approach, 244, 257f technology related to, 240–241, 240f–241f transducer technology and, 76 3D matrix array transducers, 76–77, 77f–78f linear/phase array transducers, 76, 76f single element transducers, 76, 76f for valvular heart disease, 515–528 aortic valve, 520–522, 520f case examples of, 525–528 data acquisition, 515–516, 516f, 517f image optimization, 516 mitral valve, 516–520, 517f, 518f pulmonic valve, 522–523, 522f, 523f tricuspid valve, 523–525, 524f Three-dimensional epiaortic ultrasonography, 641 Three-dimensional intracardiac echocardiography, 652, 653f Three-dimensional matrix array transducers, 76–77 Three-dimensional (3D) speckle tracking, 92, 94f–95f frequency, 95 modes, 96, 97f for morphological study, 94f one-beat acquisition, 96 raw data storage, 95

I-XL


scan range/volume width, 96 triggered full volume, 96, 97f volume rate, 96 wall motion tracking, 92, 95, 97f Three-dimensional speckle tracking and strain, 715, 717, 717f–719f Three-dimensional speckle tracking echocardiography (3DSTE), 372–373, 373f, 374f, 1727–1728, 1727f area strain measurement and, 373, 375, 375f, 375T clinical applications of, 373–374, 376t use of, 404–405, 405f Three-dimensional stress echocardiography, 1328–1336 advantages of, 1329–1330, 1330t contraction front mapping in, role of, 1334–1335 contrast in, 1335 current standards vs., 1331–1334 adenosine stress test, 1333–1334 dipyridamole stress test, 1334 dobutamine stress test, 1331–1333 treadmill exercise stress test, 1333 future directions, 1335 image acquisition in, 1330–1331 overview, 1328 parametric imaging in, 1334 postacquisition analysis, 1331 stress protocol in, 1331 three-dimensional transducers, 1329, 1329f vs. 2DSE, in wall visualization, 1334 Three-dimensional transducers, 1329 Three-dimensional transesophageal echocardiography (3D TEE), 18, 507–514 aortic valve display in short-axis view by, 511f–512f biplane (X-plane) image of left atrial appendage, 509f image display recommendations, 511, 511t image optimization, 510 colors, 510 compression, 510 cropping and rotation, 510 gain, 510 smoothing, 510 imaging modalities in, 509t full volume, 509 full-volume and live 3D color flow, 509

real time (RT) 3D, 508 simultaneous biplane mode, 509 zoom view, 508 imaging protocol for, 510t indications for, 508t procedure for image acquisition, 508–509 imaging sequence, 509–510 preprocedural planning, 508 RT3D TEE imaging, advances in, 511–512 technology for, 507 uses of, 512 catheter-based LAA closure, 512 congenital heart disease, 513 LAA clot, detection of, 512 left ventricular function and dyssynchrony assessment, 514 mitral prosthesis paravalvular leak closure, 512 mitral stenosis and balloon valvotomy, 513–514 mitral valve assessment, 513 transcatheter aortic valve replacement, 512–513 trans-septal puncture, 512 Three-dimensional transthoracic echocardiography examination, 268–286 aortic annulus, 280 aortic regurgitation, 280 data acquisition, methods for cropping, 269–270 3DE color flow Doppler imaging, 269 image display, 269–270 multiplane mode, 268–269 multiple-beat 3DE imaging, 269 real time 3DE, 269 tomographic slices, 270, 270f left ventricular assessment image acquisition methods, 270, 270f LV regional function, 271–272 normal values, 272 volume and systolic function assessment, 271 mitral regurgitation, 282–283, 282f, 283f mitral stenosis, 280–282, 281f mitral valve assessment, 280, 281f pediatric and fetal cardiac pathologies and, 285–286 pulmonic valve disease, 284, 284f, 285f regional LV function, 276

Index

aortic stenosis, 279 aortic valve assessment, 278f, 279, 279f contractile reserve, 276 left and right atria, 276–277, 277f left ventricle twist, 276 right ventricle, 277–278 valvular assessment, 278, 278f reproducibility, 272–273 3D speckle-tracking applications, 275, 275f 3D stress echocardiography, 274–275, 274f global LV function, evaluation of, 276 LV mass, 273–274, 273f methods of validation, 275–276 tricuspid valve disease, 283–284, 283f, 284f Three-dimensional TTE, 159–161, 161f Thyroid disorders, 1879–1880 T2* (star) imaging, 2020 Time–acoustic intensity curve, 442 Time gain compensation (TGC), 61 Tissue Doppler (TD) imaging, 14, 64, 72, 349–357, 360, 382 in atrial fibrillation, 353 color TD imaging, 349 development of, 350 diastolic function, assessment of, 352–353, 355f, 356f for LV dyssynchrony, 353, 354f LV filling pressures, estimation of, 352–353 myocardial disease and, 350–352 and prognosis, 354–355 RV function, assessment of, 354, 356f–357f spectral TD imaging, 349 and technical considerations, 349–350, 350f transthoracic echocardiogram, 137 uses of, 350–357 Tissue plasminogen activator (tPA), 1996 Tissue velocity imaging. See Tissue Doppler TomTec Cardiac Performance Analysis, 380 Torsion (cardiac motion) with co-contraction of base and helix, 1190f compression, 1188 definitions, 1183–1184 during ejection, 1191f left ventricle, 1186–1188, 1186f

longitudinal shortening, 1188 structural reasons for, 1184f and untwisting, 1200 Total anomalous pulmonary venous connection (TAPVC), 1577, 1672, 1673–1678, 1673f, 1674f–1675f. See also Pulmonary veins anomalous drainage of, 1676 diagnosis steps in, 1673–1676 echocardiographic goals, 1673 features of, 1673 infracardiac, 1674 pulmonary vein stenosis and, 1678 pulmonary venous confluence, 1673–1675 septum primum malposition defect and, 1676–1678, 1677f Total anomalous pulmonary venous return (TAPVR), 1743 Toxic cardiomyopathies, 1396–1397 adriamycin-induced cardiomyopathy, 1397f alcohol-induced cardiomyopathy, 1397 chemotherapy-induced cardiomyopathy, 1396–1397 Training, in echocardiography, 750–751, 759f, 760f appropriate use criteria, 758 cardiac sonographers, training of, 753–754 certification and maintenance of proficiency, 758, 759f, 760f contrast echocardiography and, 757 CT and MRI, training in, 755 duration and sites, 755 fellowship training, 751–752, 752t content of, 754–755 level 1 training, 751 level 2 training, 751 level 3 training, 752 intraoperative TEE and, 756–757 intravascular and intracardiac ultrasound and, 757 noncardiologists, training of, 752–753 in pediatric echocardiography and congenital heart disease, 753 special echocardiographic procedures and, 755 stress echocardiography and, 757 three- and four-dimensional TTE and TEE and, 757 tissue Doppler and speckle tracking echocardiography, 757–758

training requirements, 751t transesophageal echocardiography and, 755, 756t Transcatheter aortic valve implantation (TAVI). See Transcatheter aortic valve replacement (TAVR) Transcatheter aortic valve replacement (TAVR), 512–513, 540–546 AVA calculation, 543 CTA for, 2058f CT and, 2029t, 2057–2059 in elderly, 1935f intra- and postprocedural monitoring by 2D/3D TEE, 543, 546, 546f patient seletion for, 543 TAVR valves, 541–543, 543f three-dimensional speckle tracking and, 376t Transducer probe, 60 Transducers, 58 Transducer technology, 102, 103f Transesophageal echocardiography (TEE), 13, 99–116, 487 acoustic shadowing, 61, 62f artifacts reverberation, 107, 109–110, 109f side lobes, 107, 108f sound velocity, effect of, 107, 107f, 107t, 108t of coronary arteries, 1338–1340 current/future technologies, 112–116 and artifacts, 113–116, 114f CMUT technique, 115f, 116, 116f color Doppler, 113, 113f, 114f power Doppler, 113, 114f spectral Doppler, 112–113, 113f image quality aperture and, 104, 106f focus and, 106, 106f frequency and, 104–105, 105f kinds of dual plane probe, 99–100, 100f matrix array probe, 101–102, 101f miniaturization technology, 102–103, 103f, 104f processing technology, 103, 104f, 105f real time, three-dimensional TEE, 102 rotary plane probe, 100, 100f, 101f single plane probe, 99, 99f transducer technology, 102, 103f variable plane probe, 100, 100f pulmonary veins, imaging of, 327 safety considerations, 110

I-XLI

acoustic energy safety, 111 electric safety, 110–111 electromagnetic compatibility, 112 heating safety, 111 mechanical safety, 111–112 three-chamber view, 60f training in, 755, 756t Transesophageal echocardiography, tricuspid valve in inferior myocardial infarction, 1014f three-dimensional, 988–990 two-dimensional, 988, 988f, 989f–990f bicaval view, 988f longitudinal plane examination, 989f mid-esophageal four-chamber view, 988f normal tricuspid valve anatomy, 989f–990f Transjugular intrahepatic portosystemic shunt (TIPS), 319 Transmitral diastolic inflow, 1126f Transmitter, 60 Transposition of great arteries (TGA), 1653–1663, 1754–1763 anatomy, 1653–1654, 1653f associated defects, 1657–1661 coronary arteries, 1661 fixed anatomical obstruction, 1660–1661 inlet VSD, 1659 left ventricular outflow obstruction, 1659–1661 septal defects, 1657–1659 VSD, 1658–1659 associated lesions, 1653 computed tomography for, 2059– 2062, 2061f coronary artery patterns in, 1661– 1663 intramural coronary, 1662–1663 inverted origin of coronaries, 1662 single left coronary artery, 1662, 1662f–1663f single right coronary artery, 1661 echocardiographic evaluation, 1654–1656 chamber size, 1655–1656, 1656f two-dimensional, 1654–1655, 1654f, 1655f Transseptal cardiac catheterization, 233 Transseptal puncture, 512, 532–533, 534f Transthoracic echocardiography (TTE), 132–162

I-XLII


apical window, 146, 148 five-chamber plane, 153–154, 153f, 154f, 154t four-chamber plane, 148–153, 148f–153f, 149t long-axis or three-chamber plane, 155, 156f two-chamber plane, 154–155, 154f, 155f beginning of, 132, 135 cardiac structures assessed in, 133t–134t apical window, 133t–134t parasternal window, 133t of coronary arteries, 1337–1338 four-chamber view, 60f imaging modalities color flow Doppler, 137 M-mode echocardiography, 136, 136f spectral Doppler, 136–137, 137f tissue Doppler imaging, 137 two-dimensional echocardiography, 135–136, 135f imaging windows and planes, 135 left ventricle and wall motion determination, 161–162, 162f parasternal window linear measurements, 139–141, 139f–141f parasternal long-axis plane, 137–139, 138f, 139f, 139t parasternal short-axis plane, 144–146, 145f–147f, 145t right parasternal long axis view, 141–142 right ventricle inflow view, 142, 142f, 142t, 143f right ventricular outflow tract view, 142–144, 143f, 143t, 144f patient positioning for, 135 pulmonary veins, imaging of, 327, 328f subcostal window color and spectral Doppler imaging, 158–159 four-chamber view, 155, 156f, 156t, 157f great vessel imaging, 157–158, 158f, 159f short-axis views, 157, 157f suprasternal notch window, 159, 160f three-dimensional, 159–161, 161f of tricuspid valve three-dimensional, 988–990 two-dimensional, 986–988, 987f

Transthoracic examination, 164–186 apical views color and spectral Doppler, 176–177, 176f five-chamber view, 178–179, 178f, 179f four-chamber view, 175, 175f–178f left ventricle, 175 long-axis view, 180, 181f, 182 LV and atrium quantitation, 180, 180f, 181f mitral and tricuspid valves, 175–176 two-chamber view, 179, 179f variations on four-chamber view, 176 parasternal long-axis view, 166–171, 167f aortic valve, aortic root and ascending aorta, 167–168, 168f calcification, 170 chamber size and function, 167, 168f Doppler imaging, 170 extracardiac structures, 170 mitral valve, 168–169, 169f M-mode measurements, 169–170, 169f, 170f pulmonary artery long axis, 171 right ventricular inflow view, 171, 171f parasternal short axis, 172–175 aortic valve, 172, 172f atria, 172–173 left ventricle, 174–175, 174f mitral valve, 174, 174f right ventricular outflow tract, 173–174, 173f, 174f set-up and patient positioning, 164, 166 standard recommended protocol, 165t–166t subcostal views abdominal aorta and inferior vena cava, 183, 183f, 184f four-chamber view, 182, 182f short-axis views, 182, 183f suprasternal views, 184–185, 185f, 186f Transvalvular pressure gradients, 1622 Transvalvular regurgitation, 1106 Transverse aortic arch, 1537f Transverse strain, 362, 363f TRAP. See Twin reverse arterial perfusion (TRAP) Traumatic tricuspid papillary muscle 2d transthoracic echocardiography, 1012f, 1013f

Index

Treadmill exercise stress test, 1333 Treadmill stress echocardiography equipment and set-up for, 1308f hyperdynamic response to stress, 1310f in ischemia, 1311f vs. coronary angiography, 1312t “Triangle of dysplasia,” 1135, 1135f Tricuspid annular plane systolic excursion (TAPSE), 177, 178f, 381–382, 1069t longitudinal contraction of RV, 1166 right ventricular ejection fraction and, 1137–1138, 1138f RV systolic function and, 1137–1138 Tricuspid atresia, 1700–1701 classification of, 1701t type I, 1700 type II, 1701 Tricuspid regurgitation (TR), 813–816, 990–1004 cardiac MRI for, 2013, 2014f color flow imaging, 814 continuous wave Doppler, 815, 815f 2d transthoracic echocardiography, 992f, 993f–996f, 1002f effect of Nyquist limit, 997f echocardiography in three-dimensional, 816 transesophageal, 816 two-dimensional, 814 flow convergence method, 814–815 hepatic veins in, 999f and HV Doppler, 310–311, 311f, 312f measurement of VC, 814 pacemaker associated, 1212–1214 lead infection associated with, 1114–1115 time course for, 1213 transthoracic echocardiography for, 1213–1214, 1213f parasternal approach for, 999f–1000f PISA method for, 992 pulmonary artery pressure, 815 pulmonary hypertension, systemic level, 995f pulsed wave Doppler, 815 rheumatic, 1002f right heart failure and, 1204 RV dimensions and function, 815–816 severity, echocardiography criteria, 993t severity of, 816, 816t

torrential, 996f transesophageal echocardiography, 1000f–1002f before and after annuloplasty, 1001f coronary sinus, 1000f two jets of, 1001f Tricuspid regurgitation velocity (TRV), 1063, 1066, 1066f, 1067 Tricuspid stenosis, 812–813, 1004–1007 carcinoid heart disease and, 1006 diet drug-induced valvulopathy, 1006 in elderly female with rheumatic heart disease, 1006f grading scales, 1004t hemodynamically significant, findings, 1004t and HV Doppler, 311, 312f Loeffler’s syndrome, 1006–1007 severity of, 813 transthoracic echocardiography three-dimensional, 1006f two-dimensional, 1005f–1006f Tricuspid valve (TV), 589–590, 1233 in adults cardiac catheterization, 1815 Ebstein’s anomaly, 1813–1814, 1815t echocardiography, 1814 MRI/CT for, 1814–1815 postoperative adult, 1815–1816 stress echocardiography, 1814 tricuspid valve surgery, 1815 anatomy of, 984, 989f–990f congenital anomalies of, 1022,1616– 1618 congenital lesions of, 1616t congenitally unguarded tricuspid orifice, 1617–1618, 1617f Ebstein’s anomaly of, 1616–1617, 1616f tricuspid valve prolapse, 1617 3DE assessment of, 278, 278f 3D echo of, 523–525, 524f and dilated cardiomyopathy, 1376 dilated cardiomyopathy and, 1376 flail, 1007–1029 M-mode echocardiography, 984–986 Ebstein’s anomaly, 986f functional events, demonstrating, 984f septal leaflet, identification, 985f systolic abnormalities, 986f using contrast injections, identification, 985f pacer and, 1215f

pulsed wave Doppler across, 1533f three leaflets of, 991f transesophageal examination three-dimensional, 988–990 two-dimensional, 988, 988f, 989f–990f transthoracic examination three-dimensional, 988–990 two-dimensional, 986–988, 987f ventricular assist devices and, 1232, 1233f Tricuspid valve annulus, 1474f Tricuspid valve diseases anatomy of tricuspid valve, 812 3DE assessment of, 283–284, 283f, 284f tricuspid regurgitation, 813–816 color flow imaging, 814 continuous wave Doppler, 815, 815f 3D echocardiography, 816 flow convergence method, 814–815 measurement of VC, 814 pulmonary artery pressure, 815 pulsed wave Doppler, 815 role of 3D TEE in operating room in, 589–590, 593–597, 601f–608f RV dimensions and function, 815–816 severity of, 816, 816t transesophageal echocardiography in, 816 two-dimensional echocardiography, 814 tricuspid stenosis, 812–813 severity of, 813 Tricuspid valve endocarditis, 1008–1015, 1058f in adult female, 1017f MRSA positive, 1020f Tricuspid valve fibroelastoma, 1023f, 1477f, 1479f Tricuspid valve myxoma, 1465f Tricuspid valve prolapse, 1007–1029, 1617 2d transesophageal echocardiography, 1010f–1011f in elderly male with dyspnea, 1011f myxomatous degeneration, 1011f prosthetic valves and, 1015, 1021f–1022f transthoracic echocardiography three-dimensional, 1011f two-dimensional, 1009f–1010f TV endocarditis, 1008–1015 TV tumors, 1015

I-XLIII

Tricuspid valve prosthesis bovine pericardial, 1022f normal functioning porcine, 1021f Tricuspid valve vegetation 2d transthoracic echocardiography, 1016f, 1018f–1019f in intravenous drug abuser adult female, 1017f–1018f adult male, 1020f–1021f transesophageal echocardiography three-dimensional, 1019f two-dimensional, 1017f–1018f, 1019f Trivial lesions, pressure gradients across, 1574 True biological valves, 1080–1081 True lumen (TL), 1977f Truncus arteriosus, 1650–1653, 1650f–1652f in adults, 1842–1844 cardiac catheterization, 1844 echocardiography, 1843 MRI/CT for, 1844 postoperative adult, 1844 surgery for, 1844 classification of, 1650–1652 Doppler imaging, 1653 echocardiography in, 1651f–1652f, 1652 two-dimensional, 1653 infant with, 1582f TRV. See Tricuspid regurgitation velocity (TRV) Trypanosoma cruzi, 1875 TTTS. See Twin–twin transfusion syndrome (TTTS) TUPLE maneuver, 551, 553f Turbulence, detection of, 66 Twin reverse arterial perfusion (TRAP), 1530 Twin–twin transfusion syndrome (TTTS), 1529–1530 Twisting (cardiac motion), 1183 Two-dimensional echocardiography (2DE), 8–9, 705 transthoracic echocardiogram, 135–136, 135f weaknesses of, 81 Two-dimensional (2D) scanning concept, 4f Two-dimensional (2D) speckle tracking, 88, 88f acquisition considerations, 88 depth, 89 dynamic range, 90

I-XLIV


frame rate, 88–89, 89f frequency, 90 gain level, 89, 89f high frame rate, 89 imaging mode, 90, 90f lateral gain, 89–90 raw data format, 90 scan range, 89 Two-dimensional speckle tracking echocardiography (2D STE), 365–367, 365f, 366f clinical application of, 367, 368t cardiac transplantation, 371 cardiomyopathies, 369–371 chemotherapy cardiotoxicity, 371–372 congenital heart disease, 372 coronary artery disease, 367 CRT for heart failure, 369 right ventricular function, 372 rotational dynamics, role of, 372, 372f valvular heart diseases, 371 Two-dimensional stress echocardiography, 1328–1329 vs. 2DSE, in wall visualization, 1334 Two-dimensional subcostal echocardiography, abdominal aorta, 222f Two-dimensional (2D) TEE examination, 480–485 esophageal intubation, 481 informed consent for, 480 patient selection for, 480 preparation and conscious sedation, 480 procedure, 481–485, 481f–485f bicaval view, 482f color Doppler interrogation of aortic valve in long axis, 483f color Doppler interrogation of aortic valve in short axis, 484f color Doppler interrogation of atrial septum, 482f color Doppler interrogation of LAA, 482f color Doppler interrogation of mitral valve, 483f color Doppler interrogation of tricuspid valve, 484f continuous wave Doppler interrogation of tricuspid valve, 484f descending aorta (DA) imaged at 0° and 90°, 485f

left atrial appendage, 481f left ventricular outflow tract view and aortic valve, 483f lower esophageal four-chamber view, 484f mid-esophagus four-chamber view at 0°, 481f mitral valve view at 0° and 90°, 483f mitral valve view at 45° and 135°, 483f pulmonic valve and right ventricular outflow tract, 484f pulsed wave Doppler interrogation of LAA, 482f pulsed wave Doppler interrogation of pulmonary vein, 482f short-axis view of aortic valve, 483f transgastric long-axis view of left ventricle, 485f transgastric short-axis view of left ventricle, 485f transgastric short-axis view of right ventricle, 485f Two-dimensional tomographic slices, 79–80 Two-dimensional transthoracic echocardiography subcostal approach abdominal aorta, 222f–223f Type B arch interruption, 1694 Type II tricuspid atresia, 1701 Type I tricuspid atresia, 1700

U UCAs. See Ultrasound contrast agents (UCAs) Uhl’s anomaly, 1618, 1618f Ultraharmonics, 421 Ultrasound artifacts, 61–63 basics of, 55–64 definition of, 4 highly focused ultrasound, 1996 history of, 4 imaging by, 57–60 A-mode, 57, 58f B-mode, 57, 58f M-mode, 58, 58f resolution, 58–60, 60f transducers and probes, 58, 58f 2D ultrasound, 58, 58f low-frequency ultrasound, 1996 microbubbles, 1996 nanodroplets, 1996

Index

problems, 1996 therapeutic applications, 1996 diagnostic ultrasound, 1996 tissue plasminogen activator, 1996 Ultrasound contrast agents (UCAs), 416–417, 417f, 441. See also Contrast echocardiography commercially available, 417, 418t idle, properties of, 417 safety of, 434–435, 435t ultrasound and, interaction between, 418–419, 419f use of, 428–431 Ultrasound frequency, and Doppler signal, 66 Ultrasound-guided compression therapy of pseudoaneurysms, 699, 700f Ultrasound-guided thrombin injection, 699 Ultrasound image, 87 Ultrasound stethoscope, 291. See also Point-of-care diagnosis Umbilical artery, pulse Doppler across, 1539f Umbilical cord vessels, 1539f Umbilical vein, pulse Doppler across, 1539f Unicuspid aortic valve, 1619 Univentricular atrioventricular connections, 1697–1700 Univentricular heart, in adults, 1845–1848 cardiac catheterization, 1847–1848 echocardiography, 1846–1847 transesophageal, 1847 MRI /CTA for, 1847 tricupsid atresia and post-fontan adult, 1845, 1846f Univentricular heart post-fontan tricuspid atresia, 1848t Unroofed coronary sinus, 1743 Unscrolled myocardial band model, 1182f Untwisting (cardiac motion), 1183 during elongation, 1193 mitral valve opening and, 1200–1201 during postejection isovolumic phase mirrors torsion, 1189 prominent left-sided vectors in, 1191–1193 torsion and, 1184–1185, 1200 Upper transesophageal and transpharyngeal examination, 487–506 arch vessels, identifications of, 488f

bilateral ostial vertebral artery stenosis, 501f–502f carotid body paraganglioma, detection of, 500f Doppler signal of vessels on transpharyngeal ultrasound, 488t internal carotid artery stent, detection of, 499f left- and right-sided carotid arteries, 494f left carotid artery stent, detection of, 498f left carotid bulb and internal carotid artery stenosis, 496f–497f left internal mammary artery, 493f left-sided carotid arteries, 489f–490f left subclavian artery, 491f–492f left subclavian artery stenosis and steal syndrome, 502f–503f left vertebral artery, 490f–491f left vertebral artery origin stenosis, 501f pan-diastolic backflow in aortic arch branches and neck vessels, 504f–505f right-sided carotid arteries, 495f, 496f right subclavian artery, 494f

V Valsalva aneurysm, sinus of, 1630–1632 Valsalva maneuver, 1126–1127 Valve perforation, 1045, 1046f bicuspid aortic, 1046f native mitral, 1046f, 1056f Valvular aortic stenosis, 1618–1624 aortic root, 1621 aortic valve annulus, 1621 aortic valve area, 1622 associated anomalies in, 1624 critical neonatal aortic stenosis, 1622–1623 hemodynamics, 1623 severity of, 1621–1622 sinotubular junction, 1621 stenotic aortic valve, morphology, 1619–1620 transvalvular pressure gradients, 1622 vs. hypoplastic left ventricle, 1623 Valvular disease, in adults, 1813–1826 aortic valve, 1821–1826 mitral valve, 1818–1820 pulmonary valve, 1816–1818 tricuspid valve, 1813–1816

Valvular heart disease, cardiac MRI, 2009–2013 aortic regurgitation, 2010–2011, 2011f aortic stenosis, 2010, 2011f mitral regurgitation, 2012–2013 mitral stenosis, 2013 tricuspid regurgitation, 2013, 2014f Valvular heart disease, 3D echo in, 515–528 aortic valve, 520–522, 520f case examples of, 525–528 data acquisition, 515–516, 516f, 517f image optimization, 516 mitral valve, 516–520, 517f, 518f pulmonic valve, 522–523, 522f, 523f tricuspid valve, 523–525, 524f Valvular heart diseases, 2D STE and, 371 Valvular regurgitation, 278 Valvular stenosis, 1033 “Valvuloarterial impedance” (Zva), 1934 Valvuloarterial impedance formula, 911 Variable plane probe, 100, 100f Vasa vasorum, 450 Vascular rings, 1691 Vasoconstrictors, 451 Vasodilators, 451 Vasodilator stress echocardiography, 1307–1308 Velocity vector imaging (VVI), 365, 365f, 380–406 analysis, 400 for cardiac resynchronization therapy response, 400–401 dyssynchrony in pediatric and congenital heart disease and, 401 application of amyloidosis, 399 cardiomyopathy, 394–396 congenital heart disease, 391–394 congenitally corrected transposition of great arteries, 392 coronary artery disease, 396–398 D transposition of great arteries, 392 exercise and, 400 fetal cardiac function, 390–391 heart transplantation, 399–400, 399f Kawasaki disease (KD), 398 myocarditis and, 398–399 in patients with diabetes, 398 pulmonary artery hypertension, 399 single ventricle, 392–394 systemic right ventricle and, 392 tetralogy of fallot, 391–392 cardiac anatomy and, 380–381

I-XLV

future directions LV twist, evaluation of, 406 MRI tagging versus MRI velocity vector imaging, 405–406 three-dimensional STE, 404–405, 405f physics of strain and, 385, 389 and reproducibility and correlation between vendors, 401–404 Vena contracta area (VCA), 278 MR severity and, 869–870 Vena contracta technique, 82 Vena contracta width, MR and, 868–869 Ventricular arterial connection, identification of, 1579–1582 concordant, 1580–1581 spatial relationship, 1582 Ventricular assist devices, 1222–1254 apical thrombi, 1230f cardiac structure and function, changes in, 1234–1240 clinical uses of, 1224–1226 dilated cardiomyopathy baseline study, 1230f with small secundum atrial septal defect, 1232f echocardiographic evaluation of, 1222–1254 explantation, 1249–1250 implantation by device strategy, 1226t left ventricular over-filling, evidence of, 1240–1246 levels of severity, 1225t list of, 1229t overview, 1222–1224 percutaneous continuous flow devices, 1250–1252 Impella device, 1250, 1251f TandemHeart, 1250–1251 postsurgical evaluation, immediate, 1234 preoperative echocardiographic evaluation, 1229–1234 aorta, 1232 aortic valve, 1231, 1231f atrial septum, 1231–1232 inferior vena cava, 1233 left atrium, 1231 left ventricle, 1229–1230 mitral valve, 1231 pericardium, 1231 pulmonic valve, 1232 right ventricle, 1233–1234 tricuspid valve, 1232, 1233f

I-XLVI


reverse remodeling, 1226 septal contour preleft, 1230f Thoratec HeartMate II, 1223f types of, 1226–1229 long-term axial flow devices, 1227– 1228 long-term third generation centrifugal flow systems, 1228–1229 short-term circulatory support, 1226–1227 ventricular size and function, 1234–1240 diastolic performance of ventricle, 1238–1240 inlet cannula, 1237, 1240f left ventricle size and function, 1234–1237 motion of aortic valve, 1238 right ventricle size and function, 1237f, 1238 Ventricular deptal defect, 1581f Ventricular morphology, echocardiography of, 1579 Ventricular myxomas, 1468–1470 Ventricular papillary muscle rupture, right in female with dyspnea, 1014f–1015f transesophageal echocardiogram, 1013f–1014f Ventricular septal contour position, 1248 Ventricular septal defect (VSD), 1361, 1543f, 1591–1599, 1743–1746, 1802–1805 closure of, 557–559, 560f direction of shunt, 1597 Doppler evaluation of, 1596–1597 color Doppler, 1596–1597 pulsed and continuous wave Doppler examination, 1597 3D TEE for, 513 midmuscular, 1544f M-mode echocardiography, 1598 morphological location, 1591–1596 doubly committed subarterial defects, 1594–1595, 1594f, 1596f inlet ventricular septal defect, 1595–1596, 1595f muscular ventricular septal defects, 1593–1594, 1593f, 1594f perimembranous, 1592–1593, 1592f, 1595f, 1596f objectives, 1591

pressure gradient across, 1597–1598 Qp/Qs ratios in, 1598 regurgitation and stenosis, 1598 restriction of, 1647f, 1648 stepwise evaluation for, 1591t suitability for device closure, 1598 TGA and, 1658 transesophageal echocardiography in, 1599 Ventricular septal defect closure, ICE imaging during, 650, 651f Ventricular septal defects, in adults, 1802–1805, 1806t cardiac catheterization, 1805 closure of, 1805 echocardiography, 1804–1805 inlet, 1804 locations of, 1804f membranous, 1803 MRI/CTA for, 1805 muscular, 1804 postoperative adult, 1805 supracristal, 1803 “venturi effect,” 1803f Ventricular septal dropout, 1543f Ventricular septal muscle rupture, 1295–1297 postmyocardial infarction, 1296f transesophageal echocardiogram, 1013f–1014f Ventricular systolic function, assessment of, traditional echocardiographic limitations in, 381–382, 381f Ventricular tachycardia (VT), 1966 apical thrombi, 1966 coronary artery disease, 1966t dilated cardiomyopathy, 1966t echocardiography, 1966 hypertrophic cardiomyopathy, 1966t left ventricle (LV), 1966 noncompaction, 1966t sarcoid heart disease, 1966t ventricular arrhythmias, 1966t arrhythmogenic RV dysplasia (ARVD), 1966 coronary artery disease, 1966 dilated cardiomyopathy, 1966 hypertrophic cardiomyopathy, 1966 infiltrative diseases, 1966 substrates, 1966

ventricular ectopy, 1966 common conditions, 1966t Ventriculoarterial discordance, 1580f Vertebral arteries, assessment of, 691–693, 694f Vijaya's echo criteria, 771, 771t Visualization ,of received ultrasound energy, 56, 56f Volume rendering, of 3DE data set, 78–79, 79f V-ScanTM, 292, 292f VSD. See Ventricular septal defect (VSD) VVI. See Velocity vector imaging (VVI)

W Wall motion abnormalities (WMA) in DCM, 1371–1372 detection of, on echocardiogram, 226 in dilated cardiomyopathy, 1371– 1372 ischemic, 1291–1292, 1292f–1293f squatting stress echocardiography in left ventricular, 1324–1325 mechanism of, 1325 Wall motion score index (WMSI), 1313f, 1343 Wall motion scores (WMS), 1158 Wall visualization, 3DSE vs. 2DSE in, 1334 Watchman, 563 Wavelength, 55 Wide-angled display, 241 Wilkins’s score, 536 William's syndrome, 1628f WMA. See Wall motion abnormalities (WMA) WMS. See Wall motion scores (WMS) WMSa. See WMS difference (WMSa) WMS difference (WMSa), 1158 vs. summed difference score, 1159f, 1159t WMSI. See Wall motion score index (WMSI) World Health Organization–International Society of Hypertension (WHO ISH), 294

Z Zoom mode, 269

Comprehensive Textbook of Echocardiography Volume 2

Recommend Documents