Heart Disease in Paediatrics

367 Pages·1989·9.907 MB·English

by  S. C. Jordan and Olive Scott (Auth.)

Heart Disease in Paediatrics
Third Edition
S.C. Jordan, md, frcp
Consultant Cardiologist,
Bristol Royal Infirmary
Olive Scott, MD, FRCP
Consultant Paediatric Cardiologist,
Leeds Regional Thoracic Centre,
Killingbeck Hospital, Leeds
S J U T T E R W O R TH
Ε I Ν Ε Μ Α Ν Ν
Butterworth-Heinemann Ltd
Linacre House, Jordan Hill, Oxford OX2 8DP
PART OF REED INTERNATIONAL BOOKS
OXFORD LONDON BOSTON
MUNICH NEW DELHI SINGAPORE SYDNEY
TOKYO TORONTO WELLINGTON
First published 1973
Second edition 1981
Third edition 1989
Reprinted 1991
© Butterworth-Heinemann 1989
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British Library Cataloguing in Publication Data
Jordan, S. C. (Stephen Christopher)
Heart disease in paediatrics - 3rd ed.
1. Children. Heart. Diseases
I. Title II. Scott, Olive, 1924-
618.92Ί2
ISBN 0 7506 0537 5
Library of Congress Cataloguing in Publication Data
Jordan, S. C. (Stephen Christopher)
Heart disease in paediatrics/S. C. Jordan,
Olive Scott. - 3rd ed.
p. cm.
Includes bibliographies and index.
ISBN 07506 0537 5
1. Heart - Diseases. 2. Paediatric cardiology.
I. Scott, Olive II. Title
[DNLM: 1. Heart diseases - in infancy and childhood.
WS 290 J82h]
RJ421.J67 1989
618.92'12-dcl9 88-39637
Printed and bound in Great Britain at the University Press,
Cambridge
Preface to the third edition
There has been great progress in the diagnosis and management of congenital heart
disease since the second edition of this book eight years ago and the third edition
has been almost completely rewritten.
New non-invasive techniques are described in detail and illustrated. The use of
Doppler echocardiography to provide haemodynamic information and the use of
Doppler colour flow imaging to produce a picture resembling an angiocardiogram
are explained. The lesions in which these techniques have replaced invasive
investigation (with great benefit to the patient) are indicated.
Interestingly, as the number of diagnostic cardiac catheterizations has declined,
the number of therapeutic catheterizations has increased. Interventional cardiology
is now established and the various procedures of balloon valvuloplasty and
angioplasty are described in a special section, as well as being appraised under the
lesions for which they are used.
Up-to-date information is given about the risks, prevention and recurrence of
congenital heart disease and the need for genetic counselling is indicated. This is
particularly important now that patients who have been operated on are having
children of their own. The use of fetal echocardiography to diagnose structural
heart lesions and fetal arrhythmias is described and advised for all mothers whose
babies are particularly at risk.
A new chapter is devoted to the prevention of heart disease in adult life and the
risk factors which operate in childhood. The chapter on social problems has been
expanded to give more information about education, exercise, immunization,
travel, life insurance, psychological problems and the value of Parents'
Associations.
New attitudes to the treatment of heart failure are discussed; the increased use of
prostaglandins is described and their value assessed. New developments in surgery
are described together with heart and heart-lung transplantation.
The authors have been fortunate in obtaining the help of Dr L. M. Gerlis (a
cardiac pathologist) to illustrate this edition. Previous diagrams have been redrawn
to produce greater clarity and new ones have been added. Line drawings help the
reader to interpret the echocardiograms which replace many of the angiocardio-
grams. We thank Dr Neil Wilson and Dr John Gibbs of Killingbeck Hospital for
some of the echocardiograms.
The aim of the book has not changed. It is not intended as a comprehensive
work. The authors have tried to keep the book simple and practical and to give
up-to-date information to paediatricians, cardiologists who occasionally see
children, general practitioners, community paediatricians, nurses and technicians.
V
vi Preface to the third edition
The principles of management remain unchanged - early referral, early
investigation, and, when necessary, early treatment, so that the child grows up with
as few secondary effects from his heart lesion as possible and can enjoy a normal or
near-normal life.
S.C.J.
O.S.
Preface to the first edition
This book does not aim to be a comprehensive work on all aspects of paediatric
cardiology. It is intended for the paediatrician and others who look after children to
use as an introduction to paediatric cardiology and to provide up-to-date
knowledge of the methods of diagnosis and treatment, particularly of congenital
heart disease. The approach is essentially a practical one. It indicates to what extent
the clinical signs and symptoms, assisted by radiological and electrocardiographic
findings, can indicate the diagnosis, and when further investigation by cardiac
catheterization and angiography will be required.
The two authors, one a paediatrician with cardiological training and one a
cardiologist with special experience in paediatric cardiology, have slightly different
views on some of the subjects, so that the text has been a result of the two
approaches. In a book of this size it has not been possible or desirable to discuss in
detail some of the more controversial aspects of paediatric cardiology, and indeed
views on such topics as early corrective surgery in infancy are changing rapidly at
the moment. This should not deter the paediatrician, as the same principles apply
with regard to referral of patients for further investigation and treatment.
Few paediatricians will be directly concerned with cardiac catheterization, but
decisions regarding surgery are frequently influenced by the results of this
investigation and a section has therefore been included on the technique and
interpretation.
One of the most striking changes in paediatric cardiology in recent years has been
the increasing interest in the management of the newborn infant with heart disease
and a special chapter has been included, which presents a scheme to simplify
diagnosis in this difficult group of patients.
S.C.J.
O.S.
vii
Chapter 1
Incidence, aetiology and recurrence of
congenital heart disease
Incidence
Congenital heart disease is the commonest single group of congenital abnormali-
ties, accounting for about 30% of the total. The incidence is at least 8/1000 live
births. There are eight common lesions which account for about 80% of all cases.
They are, in descending order to prevalence, ventricular septal defect, patent
ductus arteriosus, atrial septal defect, tetralogy of Fallot, pulmonary stenosis,
coarctation of the aorta, aortic stenosis and transposition of the great arteries. The
remaining 20% or so is made up of a variety of more rare and complex lesions.
Figures for the prevalence of the various lesions vary in different regions and are
dependent on the time at which they are assessed. Table 1.1 gives the incidence in
Bristol in different years and includes lesions with an incidence of 1% or more of
the total.
Table 1.1 Bristol congenital heart disease register 1966-87. Incidence of lesions comprising more than 1%
of total
Lesion 1966-76 1977-87 1966-87
Ventricular septal defect 29.4 36.1 33.3
Atrial septal defect 9.4 8.2 8.7
Pulmonary stenosis 9.1 6.9 7.8
Patent ductus arteriosus 6.4 7.9 7.3
Coarctation 6.2 5.9 6.0
Aortic stenosis 5.4 5.7 5.6
Tetralogy of Fallot 6.2 4.6 5.3
Transposition 4.5 3.8 4.1
Atrioventricular septal defect 2.7 3.6 3.2
Pulmonary atresia 3.0 2.6 2.8
Primitive ventricle — 2.2 1.9
Tricuspid atresia 1.2 1.5 1.4
Mitral regurgitation 1.3 1.4 1.4
Aortic atresia 1.1 1.4 1.3
Hypertrophic cardiomyopathy 1.2 1.3 1.3
Total anomalous pulmonary venous connection 1.3 1.2 1.2
Ebstein's anomaly 1.2 — 1.0
Total 89.6 94.3 93.6
3
4 Incidence, aetiology and recurrence of congenital heart disease
Aetiology
The first question parents ask when they realize that their child has a heart defect
is, 'What caused it?' Unfortunately, we are still unable to answer this question in
the majority of patients. Only a minority of cases run in families. The most likely
explanation is that there is a genetic susceptibility for the mother to have a baby
with congenital heart disease, but it only actually happens if some environmental
hazard occurs at the appropriate time during her pregnancy. Nora and Nora (1983)
have constructed a timetable for teratogenic activity to occur to produce the various
lesions. This of course depends on the time when the various parts of the heart are
forming. For truncus arteriosus to occur, the most sensitive vulnerable period is
between 18 and 29 days' gestation, for atrioventricular defects between 18 and 33
days, and for ventricular septal defect between 18 and 39 days. The vulnerable
period is longer - 18-50 days - in atrial septal defect and semilunar valve
abnormalities. In patent ductus and coarctation of the aorta it is 18-60 days. This
gives a guide in looking for a possible teratogenic factor at a particular time in
pregnancy. The problem is that the mother may not have realized that she was
pregnant when the teratogenic insult occurred.
Inheritance
Hypertrophic obstructive cardiomyopathy, sometimes atrial septal defect and
supravalvar aortic stenosis all behave as autosomal dominant traits. Marian's
syndrome is an autosomal dominant disorder in which there is cardiac involvement;
Pyeritz, Brinker and Varghese (1979) estimate that nearly all patients have
echocardiographic evidence of aortic dilatation or mitral valve prolapse or both.
Idiopathic mitral valve prolapse appears to be inherited in an autosomal dominant
mode with variable expressivity (Devereux and Brown, 1983). The Holt-Oram
syndrome is caused by an autosomal gene with dominant inheritance but there is
variable expression in the limb anomalies; about one-half of patients have cardiac
anomalies, most commonly atrial and ventricular septal defects. At least 10% of
patients with Noonan's syndrome (a phenocopy of Turner's syndrome) have been
shown to have dominant inheritance and the figure may be higher than that.
One-half of patients with Noonan's syndrome have a heart lesion, most commonly
dysplastic pulmonary valves (see pages 138, 326).
Chromosomal aberrations
About 6-10% of all patients with congenital heart disease have some chromosomal
aberration (Hoffman and Christianson, 1978). On the other hand, about 30% of
newborn infants with various chromosomal aberrations have congenital heart
disease. The incidence in trisomy 13 is as high as 90% and in trisomy 18, 80%. The
commonest heart lesions in chromosomal aberrations are septal defects and patent
ductus arteriosus. About 40% of patients with Down's syndrome have congenital
heart disease (Roussay et al., 1978) and at least 40% of these have atrioventricular
defects (Park et al., 1977). (A quarter of all patients with atrioventricular defects
have Down's syndrome (Greenwood and Nadas, 1976).) Ventricular septal defects,
tetralogy of Fallot and patent ductus (in descending order of prevalence) also occur
in Down's syndrome. Twenty per cent of patients with Turner's syndrome have
coarctation of the aorta or aortic stenosis or both.
Aetiology 5
Environmental factors
There is much more concern now in identifying environmental factors in the hope
of preventing exposures to them during early pregnancy. Drugs, infections and
maternal illnesses have all been implicated.
Drugs
The drugs which may cause cardiovascular anomalies are listed below, together
with the most common lesions produced.
Alcohol Transposition of great arteries;
Ventricular and atrial septal defects;
Patent ductus arteriosus
Amphetamines Transposition of great arteries;
Ventricular and atrial septal defects;
Patent ductus arteriosus
Phenytoin Pulmonary and aortic stenosis;
Coarction of the aorta;
Patent ductus arteriosus
Lithium Particularly Ebstein's abnormality of the tricuspid valve
Sex hormones Transposition of great arteries;
(oestrogens and Tetralogy of Fallot;
progestogens) Ventricular septal defect
Infections
Rubella has been most implicated but other viruses, particularly cytomegalovirus
and herpes virus, have been found to be teratogenic (Blattner et al., 1973). The
association of the mumps virus with endocardial fibroelastosis has not been proven
(Chen, Thompson and Rose, 1971).
Maternal conditions
Diabetes mellitus in the mother carries a 5% risk of structural heart disease in
the fetus (Rowland, Hubbell and Nadas, 1973). A form of hypertrophic car-
diomyopathy also occurs in these infants but this resolves with time and can be seen
to do so on echocardiographic studies. Meticulous control of the diabetes is
thought to reduce the risks of malformations (Miller et al. 1981). Systemic lupus
y
erythematosus carries a risk of complete heart block in the fetus (Scott et al., 1983).
Twin studies
Monozygotic twins have double the incidence of heart defects compared with single
pregnancies (Burn and Corney, 1984). The monozygotic process itself is liable to
cause heart defects, perhaps associated with altered haemodynamics in utero. The
possibility of one twin being affected or both of them is equally common.
Multifactorial inheritance
To summarize, the most readily acceptable theory for the genetic basis of
congenital heart disease is the multifactorial hypothesis. This suggests that the
genetic material concerned with the normal development of the heart is carried on
a number of genes and that abnormalities of these genes may not in themselves be
6 Incidence, aetiology and recurrence of congenital heart disease
enough to cause cardiac abnormalities, but in the presence of other environmental
factors the genes predispose to the occurrence of such defects. In other words there
is a genetic susceptibility to develop congenital heart disease if the appropriate
environmental hazard occurs. Furthermore, the environmental hazard must occur
during a narrow sensitive period of pregnancy between the second and ninth weeks.
Greater effort must be made to find the particular environmental hazards which
may interact with the genetic predisposition to cause cardiac anomalies. There has
already been a fall in the number of patients presenting with the rubella syndrome -
and the thalidomide syndrome no longer occurs. Doctors must be aware of the
effects of alcohol, lithium, amphetamines, anticonvulsants and sex hormone drugs
and try to prevent them being taken during the vulnerable period of pregnancy.
There must be careful records from mothers of babies with heart disease to try to
identify new teratogens. Sometimes there is a brisk rise in the frequency of a
particular heart lesion in the newborn and a possible teratogen operating 7 or 8
months earlier must be sought.
If an uncommon abnormality suddenly increases in frequency it is much more
likely to be noticed (e.g. the increase of cases of Ebstein's malformation associated
with lithium) than if it is a common abnormality such as a ventricular septal defect.
Some agents may not be harmful to the general population but affect certain groups
with some genetic predisposition to cardiovascular malformations. It is well to
remember that substances which are teratogenic in animals are not necessarily so in
man.
Research in identifying genetic risks is progressing and there is hope for better
prevention in the future.
Recurrence in family
If one sibling in a family has congenital heart disease, the risks of another child
being affected varies in individual lesions and is in the region of 1—3%. Nora and
Nora (1978) have combined the data in various series to give a figure for the overall
risk. Table 1.2 summarizes their findings. There is a high degree of concordance in
that two siblings usually have the same lesion or one of its components (e.g.
pulmonary stenosis or ventricular septal defect occurs in siblings of patients with
tetralogy of Fallot).
Now that children with congenital heart disease survive to have children of their
own it is important to know the risks of their children being affected. It is important
first to determine whether any of the known teratogens exist such as phenytoin or
rubella or whether the mother has diabetes, is an alcoholic or smokes heavily, as
these will increase the risks. A family history of heart disease will also increase the
risks as will the presence of known syndromes such as Noonan's and Holt-Oram.
The results of various studies are widely different. Emmanuel et al. (1983) found an
incidence of 10% of heart defects in the offspring of mothers with atrioventricular
defects. Rose et al. (1985) found an overall recurrence risk of affected offspring of
8.8%. Dennis and Warren (1981) studied the recurrence in the offspring of patients
with ventricular septal defects and right ventricular outflow tract obstruction or
combination of the two, and found a recurrence rate of only 3.4%. Czeizel et al.
(1982) found an incidence of 4.9% in the offspring of patients who had had surgery
for congenital heart disease. Whittemore, Hobbins and Engle (1982) found an
incidence in offspring of 16% but there may be a bias because they focused on more
Recurrence in family 7
Table 1.2 Recurrence risks if one child has congenital heart
disease
Anomaly Combined suggested risk (%)
Ventricular septal defect 3.0
Patent ductus arteriosus 3.0
Atrial septal defect 2.5
Tetralogy of Fallot 2.5
Pulmonary stenosis
Coarction of aorta
Aortic stenosis 2.0
Transposition
Atrioventricular defects
Tricuspid atresia
Ebstein's anomaly ^ ^
Truncus arteriosus
Pulmonary atresia
Hypoplastic left heart 2.0
Table 1.3 Recurrence in offspring if one parent has congenital
heart defect (After Nora and Nora, 1983)
Anomaly Combined suggested risk (%)
Ventricular septal defect 4.0
Patent ductus arteriosus 4.0
Atrial septal defect 2.5
Tetralogy of Fallot 4.0
Pulmonary stenosis 3.5
Coarctation of aorta 2.0
Aortic stenosis 4.0
severe cases. Nora and Nora (1978) have combined the various studies and
suggested figures for the risk of recurrence. Table 1.3 summarizes these. More
prospective studies are needed but it seems clear that the risk to the offspring of a
parent with congenital heart disease is greater than the risk to the siblings of an
affected child.
Fetal echocardiography
A service is now becoming available in major centres to provide fetal
echocardiography, particularly for mothers who already have one child with a heart
lesion or have congenital heart disease themselves. Great progress has been made
in this field and by the eighteenth week of fetal life most major heart defects can be
identified. Mothers should therefore be offered this service. Allen (1986) found
that in over 2500 pregnancies studied, no major false positive diagnosis was made.
Some minor defects were overlooked and it may be impossible to avoid this;
nevertheless, the prognosis in all such minor lesions is good. Coarctation of the