Tiny Tots and Tender Hearts

Transcription

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2 Tiny Tots and Tender Hearts i

3 iii Tiny Tots and Tender Hearts An Introduction to Heart Diseases in Children R.V. Kumar Consultant Cardiac Surgeon Professor of Cardiothoracic Surgery Nizam s Institute of Medical Sciences Hyderabad I.K. International Publishing House Pvt. Ltd. NEW DELHI BANGALORE

4 iv Published by I.K. International Pvt. Ltd. S-25, Green Park Extension Uphaar Cinema Market New Delhi (India) ik_in@vsnl.net ISBN I.K. International Publishing House Pvt. Ltd. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission from the publisher. Published by Krishan Makhijani for I.K. International Pvt. Ltd., S-25, Green Park Extension, Uphaar Cinema Market, New Delhi and Printed by Rekha Printers Pvt. Ltd., Okhla Industrial Area, Phase II, New Delhi

5 Dedicated to my father Sri R. Srinadha Rao who was an Ardent Scholar, Reputed Judge, and above all a great humanist

6 vii Foreword It gives me a great pleasure to review this book by Prof. R.V. Kumar and write a few words of introduction. The beauty of this work is the simple and easily understood way of narration about the anatomy of the heart and incidence, etiology, and various techniques used for the diagnosis of congenital heart diseases. This is followed by a detailed description of various commonly encountered lesions. Coloured illustrations of the anatomy and physiological consequences are included in each chapter to simplify the understanding of these complex heart defects. The book also covers the valvular heart diseases, intervention procedures, pericardial diseases, infective endocarditis, conduction problems, end stage heart disease, and heart transplantation. It also discusses the expected quality of life after the correction of congenital heart diseases etc. The book is a valuable contribution by Prof. R.V. Kumar, and focuses on simple and easily understood terms of heart defects in infants and children. This valuable information is lucidly presented as a stand-alone work, instead of being buried in the textbooks of cardiac surgery, which makes it very difficult for vast amount of readership. I hope this work will be helpful for medical students, nurses, and all other preclinical persons dealing with children suffering from heart diseases. It will also prove helpful to cardiologists, pediatricians, and cardiac surgeons. I am sure this work will provide a valuable tool for a large number of people

7 viii Foreword involved in medical care of tiny tots with ailing heart, and should be available in every facility offering such care. We wish the project a success. Prof. I.M. Rao Consultant Pediatric Cardiac Surgeon Al Mafraq Hospital Abhudabi. (Formerly Professor of Cardiothoracic Surgery All India Institute of Medical Sciences New Delhi)

8 ix Preface Children s heart disease is a real multidimensional problem. A number of specialists starting with general practitioners, pediatricians, obstetricians, cardiologists, cardiac surgeons and anesthetists take part in their care from birth onwards, either before, during or afterwards. Further, a host of paramedical personnel like nurses, perfusionists, counseling personnel, who are working in the above specialties, also participate in caring for these children. All these medical and paramedical personnel are expected to have a basic knowledge of disease process, etiology, diagnostic modalities, treatment options, and prognostic implications. Presently, the available information regarding these aspects of heart diseases is from voluminous textbooks of Cardiology, Pediatrics, or Cardiac Surgery. There is no book available in simple language, which is informative and can be useful as an introduction to all those who are interested in these specialties. In the present scenario, a need is felt to introduce the subject in a simple way, which brings out the concept of disease, management options, and outcome predictions, without compromising the accuracy, complicated scientific jargons and mind-boggling statistics. With these daunting goals, a humble attempt has been made in the form of an illustrated book, which is not voluminous, is easy to carry, and can be a guide to the patients and paramedical staff in these fields. I leave it to the readers to judge how much I have succeeded in meeting these targets. The initial chapters cover the common congenital heart defects, their causes, symptoms, how they are diagnosed, what is open heart surgery,

9 x Preface various management strategies and outcomes. The basics of other heart diseases such as valvular heart disease, pericardial, myocardial diseases, infective endocarditis, rhythm disturbances, and heart transplantation are also included in this book. A special chapter is introduced, which deals with the role of catheter intervention, re-operations, and re-interventions in children. I also tried to give answers pertaining to the quality of life after surgery in these children, psychological aspects of heart disease, and chances of the disease recurring in siblings and progeny. At the outset of this book, I would like to express my gratitude to my teachers, Prof. P. Venugopal, Prof. I. M. Rao, Prof. A. Sampath Kumar, Prof. Balram Airan, Dr. K. S. Iyer, Dr. Rajesh Sharma, Dr. Anil Bhan, Department of Cardiac, Thoracic and Vascular Surgery, All India Institute of Medical Sciences, who taught me this subject. My heart felt thanks to Jaroslov Stark, Marc R. Deleval, and Dr. Martin Elliot, who nurtured my interest in this specialty at Great Ormond Street Hospital for sick children, London. I am deeply indebted to Prof. Rajan Tandon, Prof. Savitri Srivastav, Prof. Anitha Saxena, Prof. Kothari, Department of Cardiology, All India Institute of Medical Sciences, who greatly contributed to my knowledge of diseases. I am also grateful to the patients at Nizam s Institute of Medical Sciences and other institutes, where I worked, and also to the Senior and Junior Faculty, who constantly supported me throughout this venture. Last but not the least, I thank my wife, Aruna and children, Srinath and Lalita who sacrificed some of their valuable family time to let me write this book. I specially thank my publisher, I.K. International Pvt. Ltd., who has taken the sacred duty of publishing this work. R.V. Kumar

10 xi Contents Foreword... vii Preface... ix Heart: The Structure... 1 Heart and its Function... 2 Heart and Electrical System... 4 Why do Children get Heart Diseases?... 6 How do the Congenital Heart Defects Develop?... 9 How and when does one come to know that a Child has Heart Disease?...12 How do the Doctors Diagnose that the Child has Heart Disease?...14 What is Open Heart Surgery?...23 Holes in the Heart...27 When is the Child's Heart Operation Considered Successful?...30 Atrial Septal Defect (ASD)...31 Ventricular Septal Defect (VSD)...34 Patent Ductus Arteriosus (PDA)...38 Common Atrioventricular Canal (CAVC)...41 Blue Babies...44

11 xii Contents Tetralogy of Fallot (TOF)...47 Transposition of Great Arteries (TGA)...52 Tricuspid Atresia (TA)...56 Total Anomalous Pulmonary Venous Connection (TAPVC) Truncus Arteriosus (TA)...63 Valvular Heart Diseases...67 Artificial Heart Valves...80 Children Heart Diseases Catheter Interventions...85 Pericardial Diseases...91 Rheumatic Fever Rheumatic Heart Disease...95 Infective Endocarditis...99 Coarctation of Aorta (COA) Reoperations and Reinterventions for Children's Heart Defects Diseases of Heart Rhythm Cardiac Arrhythmia Diseases of the Heart Muscles Cardiomyopathies Heart Transplantation Heart Diseases in Children Psychological Problems What will be the Quality of Life after Heart Operation? Some Figures and Facts about Congenital Heart Diseases What is the Risk of Recurrence of Heart Disease in Family Members Index...137

12 Heart: The Structure 1 The human heart has four chambers. The two upper chambers are called ATRIA (Singular: atrium), one on the right side and another on the left. These chambers receive blood from various parts of the body. They have a wall separating each other, which is called ATRIAL SEPTUM. The two lower chambers that work as pumping chambers are called VENTRICLES. The wall between these two pumping chambers is called VENTRICULAR SEPTUM. The left ventricle pumps out oxygenated blood to the various parts of the body. Whereas the right ventricle pumps out deoxygenated blood into the lungs. The main blood artery, which carries blood from the left ventricle to the various parts of the body, is called AORTA. Pulmonary Artery carries blood from the right ventricle to the lungs. Coronary Arteries supply blood to the muscular tissue of the heart. Deoxygenated blood from the lower parts of the body reaches the heart through INFERIOR VENA CAVA and from the upper parts of the body through the SUPERIOR VENA CAVA (Fig. 1.1). Head and upper extremity Superior vena cava Right atrium Pulmonary valve Tricuspid valve Right ventricle Infererior vena cava Aorta Pulmonary artery Pulmonary vein Left atrium Mitral valve Aortic valve Left ventricle Trunk and lower extremity Fig. 1.1 Normal Human Heart

13 Heart and its Function 2 The heart provides circulation in the entire body. The blood circulation is divided into three main systems (Fig. 2.1): 1. Oxygenated blood going to the various parts of the body and coming back to the heart as deoxygenated blood. This system is called SYSTEMIC BLOOD CIRCULATION. 2. Deoxygenated blood going to the lungs from the heart and coming back as oxygenated blood. This system is called PULMONARY BLOOD CIRCULATION. 3. Oxygenated blood supply to the heart comes by itself through coronary arteries and deoxygenated blood coming back through coronary sinus. This system is called CORONARY CIRCULATION. These three circulations continuously work efficiently as one-way traffic without jams due to the excellent structures present in the heart called VALVES. Let us now see how this machinery works. 1. Deoxygenated blood from various parts of the body reaches the heart through Superior and Inferior Vena Cava, into the right Atrium. 2. From this receiving chamber blood reaches the right pump, the right Ventricle, through the Tricuspid Valve. The Tricuspid Valve prevents backflow of blood into the right Atrium.

14 Heart and its Function 3 3. Right Ventricle pumps the deoxygenated blood through the Pulmonary Arteries across the pulmonary valve into the lungs. The Pulmonary Valve prevents backflow of blood into the right Ventricle. 4. Oxygenated blood from the lungs reaches the left Atrium through Pulmonary Veins. From this receiving chamber blood reaches the left pump Left Ventricle through the Mitral Valve (Bicuspid Valve). The Mitral Valve prevents backflow of blood into the left Atrium. 5. The left Ventricle pumps the oxygenated blood across the Aortic Valve into the Aorta. The Aortic Valve prevents the backflow of blood into the left Ventricle. Thus, the cycle of blood circulation goes on and on in a very systematic fashion to keep all of us alive. Systemic circulation Blood supply to head and upper part of the body Capillaries Lung Lung Pulmonary circulation Pulmonary circulation Blood supply to lower part of the body Systemic circulation Fig. 2.1 Normal Blood Circulation 3

15 Heart and Electrical System 3 We have learnt about the CIVIL and MECHANICAL aspects of the Heart in the previous two chapters. Now, in this chapter, we shall learn about the Electrical System of the heart which is called CONDUCTION SYSTEM of the heart (Fig. 3.1). Sinus node A-V node A-V bundle Internodal pathways Left bundle branch Right bundle branch Fig. 3.1 Electrical System of the Heart The seat of heartbeat is situated near the Superior Vena Cava in the form of specialized excitable tissue known as the Sinoatrial Node. This is responsible for our normal and regular heartbeat called THE NORMAL SINUS RHYTHM. The second station of the heatbeat, similar but slow, in hierarchy is the tissue located in the upper part of the Ventricular Septum

16 Heart and Elecrical System 5 known as ATRIOVENTRICULAR NODE. This transmits the sinus impulses from the sinoatrial node to the ventricles and works as relay station. If, for any reason, the sinoatrial node malfunctions, this takes over the function of heart and sustains the life. From the Atrioventricular node, the conduction tissue continues and the bundle divides into two. The branch which goes to the left ventricle is called left bundle branch and the other branch, which goes to the right ventricle, is called the right bundle branch. As the voltage fluctuations happen in our daily life same is the case of heart. When the heart beats faster, the condition is called Tachycardia and when it beats very slowly, the condition is termed Bradycardia. We will learn more about these in the chapter Cardiac Arrhythmia (Chapter 29). 5

17 Why do Children get Heart Diseases? 4 All of us are bothered by this question at some time or the other. Like all other mysteries in nature this also evades a proper satisfying scientific answer. Though modern science could not solve this, surely it has shown some promises. 1. Some heart diseases are hereditary and transmit from one generation to the other generation through genes. For example, i. Hypertrophic cardiomyopathy ii. Supravalvular Aortic Stenosis iii. Atrial Septal Defect iv. Marfan s Syndrome v. Mitral Valve Prolapse vi. Noonan Syndrome 2. Chromosomal abnormalities Chromosomes are the subcellular structures, which host the genes. The children with heart disease are found to have chromosomal abnormalities in near about 6-10% of cases. Similarly, the children with chromosomal abnormalities are associated with congenital heart disease in about 30% of the cases. For example, i. Trisomy 13 90% Ventricular Septal Defect (VSD) or Patent Ductus Arteriosus (PDA)

18 Why do Children Get Heart Disease 7 ii. Trisomy 18 80% PDA,VSD, Pulmonary Stenosis (PS) iii. Trisomy 21 40% Atrioventricular Defects (AVD), VSD iv. Turner s Syndrome 20% Coarctation of Aorta (CoA), Aortic valve Stenosis (AS), Tetralogy of Fallot (TOF), Patent Ductus Arteriosus (PDA) 3. Maternal illness during pregnancy Sometimes when pregnant mothers develop fever with body rash, early in the pregnancy, the chances of their children to develop congenital heart disease increases. For example, (i) Rubella: Children develop PDA, Pulmonary Artery branch Stenosis. (ii) Mumps: Children develop endocardial fibroelastosis. Other illnesses in pregnant mothers may also give rise to children with congenital heart disease. For example, (i) Diabetes: Hypertrophic cardiomyopathy (ii) Systemic Lupus Erythematosus (SLE): Congenital heart block. (iii) Phenylketonuria: Ventricular Septal Defect, Atrial Septal Defect, and Patent Ductus Arteriosus. 4. Maternal medication during pregnancy Some medicines taken by mothers in early pregnancy are also known to cause some types of heart diseases in the children. For example, (i) Alcohol: Transposition of Great Arteries, Ventricular Septal Defect and Patent Ductus Arteriosus. (ii) Amphetamines (Stimulators): Transposition of Great Arteries, Ventricular Septal Defect, Atrial Septal Defect, Patent Ductus Arteriosus. 7

19 8 Tiny Tots and Tender Hearts (iii) Phenytoin (Used for Fits): Pulmonary Stenosis, Aortic valve Stenosis, Coarctation of Aorta, Patent Ductus Arteriosus. (iv) Lithium (Used for depression): Ebstein s disease. (v) Male and Female hormones: Transposition of Great Arteries, Tetralogy of Fallot, Ventricular Septal Defect. 5. Syndromes Sometimes the children with congenital heart diseases are also born with congenital defects of other body parts. For example, Skin, Bones, Face, Brain, Lungs, Gastrointestinal tract, Kidneys, Eyes and Ears. Some of these defects form into well defined clusters or constellations. In medical term such associations are known as syndromes. Usually the syndromes are named after the doctor who first described it. Syndromes Heart Diseases (i) Ellis-van Creveld syndrome Single Atrium, VSD (ii) Holt-Oram syndrome ASD, VSD (iii) Noonan syndrome PS, ASD (iv) Rubinstein-Taybi syndrome VSD, PDA (v) TORCH syndrome ASD, TOF (vi) Williams syndrome Supravalvular AS (vii) VATER Anomalies VSD, TOF, ASD, PDA (viii) Down s syndrome Atrioventricular Septal Defects (AVSD) 8

20 How do the Congenital Heart Defects Develop? 5 As we have seen in the previous chapter that nobody knows clearly as to why do the heart defects develop at birth. But there is definite scientific evidence about how they are formed based on the embryological studies, both in humans and in other animals. When the embryo is two weeks old in the mother s womb two heart tubes are formed in the region of the chest. In the third week both the tubes unite to form a single tube. In the fourth week of gestation, the heart tube forms five divisions by four constrictions. These parts are (Fig. 5.1): 1. Aortic Arch; 2. Ventricle; 3. Sinus Venosus; 4. Bulbous cordis; 5. Atrium. The heart tube bends to the right and takes the form of the letter 'S'. In the fourth week, superior and inferior vena cava develop from sinus venosus. Pulmonary veins also form at the same time. Between days, the atrial and ventricular septums develop. In the fifth week, the aorta and the pulmonary artery develop from Bulbous cordis. Any deviation in the sequence of this systematic development results in the birth defects in the child's heart. For example, (i) There can be holes in the heart. (ii) One or other chambers may be under or over developed. (iii) Valve may be constricted and become narrow. (iv) Entire heart or one of chambers may form in the other.

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