A complete cardiovascular examination should start with careful inspection of the child asking fi ve questions.
1. Is the child breathless? If a child is breathless as a result of a cardiac abnormality, it suggests pulmonary vascular engorgement, usually caused by heart failure (Table 8.3). This may result from increased pulmonary blood fl ow as in the case of a left to right intracardiac shunt—VSD, patent ductus arteriosus (PDA) and AVSD—or due to pulmonary venous engorgement—mitral regurgitation, dilated cardiomyopathy, obstructed total anomalous pulmonary venous return and pericardial effusion.
Table 8.1: Conditions associated with congenital heart disease
Association Defect(s)
Chromosomal abnormality:
Trisomy 21 VSD, AVSD (in 50%)
Trisomy 18 VSD, PDA, pulmonary stenosis (in 99%)
Trisomy 13 VSD, PDA, dextrocardia (in 90%)
5p−/Cri-du-chat VSD, PDA, ASD (in 25%)
XO (Turner) Coarctation, aortic stenosis, ASD (in 35%) XXXXY (Klinefelters) PDA, ASD (in 15%)
Syndrome:
Noonan Dysplastic pulmonary stenosis
Williams Supravalve aortic stenosis, branch
pulmonary stenosis
DiGeorge VSD, tetralogy, truncus, aortic arch
abnormality
CHARGE VSD, tetralogy
VACTERL VSD, tetralogy
Holt-Oram ASD
Friedreich’s ataxia Hypertrophic cardiomyopathy, heart block
Apert VSD, tetralogy
Ellis-van Creveld Common atrium
Pompe’s (GSD II) Hypertrophic cardiomyopathy
Leopard Pulmonary stenosis, cardiomyopathy, long
PR interval
Muscular dystrophy Dilated cardiomyopathy Tuberous sclerosis Cardiac rhabdomyomata
Pierre Robin VSD, PDA, ASD, coarctation, tetralogy Long QT syndrome Long QT interval and torsades de pointes Maternal conditions:
Rubella PDA, branch pulmonary stenosis
Diabetes VSD, hypertrophic cardiomyopathy
(transient) SLE (anti-Ro/La
positive)
Congenital heart block
Phenylketonuria VSD
Lithium Ebstein’s anomaly
Sodium valproate Coarctation, HLHS
Phenytoin VSD, coarctation, mitral stenosis
Alcohol VSD
Table 8.2: Classifi cation of congenital heart disease in childhood
Acyanotic defects
Increased pulmonary blood fl ow: Atrial septal defect
Ventricular septal defect Atrioventricular septal defect Patent arterial duct Normal pulmonary blood fl ow:
Pulmonary stenosis Aortic stenosis Coarctation of the aorta Cyanotic defects
Normal or reduced pulmonary blood fl ow: Tetralogy of Fallot
Transposition of the great arteries Critical pulmonary stenosis Ebstein’s anomaly Pulmonary atresia Tricuspid atresia
Single ventricle with pulmonary stenosis Increased pulmonary blood fl ow:
Total anomalous pulmonary venous drainage Hypoplastic left heart syndrome
Truncus arteriosus
Single ventricle without pulmonary stenosis
Table 8.3: Causes of heart failure by age
First week – Left heart obstruction (HLHS, aortic stenosis, coarctation), arrhythmia
First month – Left to right shunt (VSD, AVSD, PDA, truncus arteriosus), arrhythmia
Thereafter – Rheumatic fever, dilated cardiomyopathy, myocarditis, endocarditis, arrhythmia
2. Is the child cyanotic? Although the absence of clinical cyanosis does not exclude cyanotic congenital heart disease, if it is present, it limits the potential diagnoses to a relatively small group of abnormalities. In the newborn, most commonly it would suggest TGA or severely obstructed pulmonary blood fl ow (tetralogy of Fallot, critical pulmonary stenosis, PAt and tricuspid
atresia). In infancy, tetralogy is the most common cause, although transposition with VSD and other rare forms of complex congenital heart disease can also present at this age. In older children, a presentation with cyanosis would suggest pulmonary vascular disease complicating a VSD or PDA. Untreated, the high pulmonary pressures ultimately irreversibly damage the pulmonary vasculature resulting in high pulmonary resistance and a reversal of the intracardiac shunt (right to left) with subsequent cyanosis. This is known as Eisenmenger’s syndrome. Rarely tetralogy and other complex forms of congenital heart disease can present in later life. 3. Is the child dysmorphic? Many children with congenital
of which are outlined in Table 8.1. Prompt recognition of a syndrome may alert the clinician to search for a particular abnormality.
4. Is the child failing to thrive? There are many causes of failure to thrive in infancy of which heart disease is a relatively minor one. The predominant groups of cardiac disorders causing poor weight gain are those resulting in breathlessness and poor feeding. These include VSD, AVSD and PDA. Whilst some children with cyanotic abnormalities also fail to grow this is far less common.
5. Does the child have any thoracic scars? If the child has had previous heart surgery, the type of scar may give clues to its nature. A median sternotomy scar suggests an open-heart procedure during which the heart would have been stopped and opened. All major intracardiac abnormalities requiring a surgical repair are corrected in this manner. A right lateral thoracotomy scar is usually only used for a right modifi ed Blalock-Taussig shunt. During this procedure a tube is interposed between the right subclavian artery and the right pulmonary artery, providing an alternative source of pulmonary blood fl ow in children who have an obstructed native pulmonary blood fl ow (tetralogy of Fallot, PAt, tricuspid atresia). A left thoracotomy scar is used in the repair of aortic coarctation, ligation of patent arterial ducts, a left Blalock-Taussig shunt and occasionally a pulmonary artery band (a ligature placed around the main pulmonary artery to protect the lungs from high pressures in children with large VSDs).
Palpation
Always start the examination by feeling the femoral and brachial pulses simultaneously. A reduction in volume or absence of the femoral pulse is strongly suggestive of coarctation of the aorta and should prompt closer examination and investigation. Although classically textbooks talk of radiofemoral delay this really only becomes appreciable as the child reaches adult size. Some children who have had previous procedures have an absent femoral pulse on one side only. It is, therefore, advisable to examine both femoral pulses.
Palpation for an enlarged liver should then be undertaken. The liver enlarges in heart failure and can reach below the
umbilicus in some children. The liver is often quite soft and diffi cult to feel in infants, particularly if the child is struggling so great care must be taken.
The heart enlarges in response to any chronic volume load. This may arise because of a right to left shunt—ASD, VSD, PDA and AVSD—because of valve dysfunction— mitral regurgitation, aortic regurgitation and pulmonary regurgitation—or because of a primary myocardial abnormality—viral myocarditis and dilated cardiomyopathy. In younger children, this can be felt as a sub-xyphoid heave by palpating just below the inferior end of the sternum. Children of all ages with a volume loaded heart may have a parasternal heave felt with the palm of the hand on the left side.
Finish off palpation by carefully placing your index fi nger in the suprasternal notch feeling for a thrill. If one is present, it is strongly suggestive of aortic stenosis, although rarely pulmonary stenosis and a PDA can produce this sign.
Auscultation
Auscultation is often diffi cult in children. The combination of fast heart rate, noisy breathing and a poorly cooperative child make it the most challenging part of the examination. To ensure nothing is missed you should follow a fi xed pattern when listening to a child’s heart. I would suggest listening with the diaphragm at all points over the left side of the praecordium, followed by the right upper sternal edge and at the back. At each point, it is important to listen to systole, diastole and the heart sounds in turn. All can provide vital diagnostic information that is easy to miss when distracted by a loud, obvious systolic murmur. Murmurs are classically graded to permit easy comparison, systolic murmurs out of 6 and diastolic out of 4 (Table 8.4).
A full discussion of the auscultatory fi ndings associated with different abnormalities will follow under the specifi c conditions.
Innocent Murmurs
By defi nition an innocent murmur has no associated with heart disease; however, it is an extremely common fi nding, reason for referral and some clarifi cation is needed. Innocent murmurs can be heard in up to 80% of children at some point. They can cause considerable diagnostic confusion so if you are in doubt get a more experienced opinion. Innocent
Table 8.4: Grading of heart murmurs
Murmur 1 2 3 4 5 6
Systolic Barely audible Quiet Easily audible Associated with
thrill
Audible without stethoscope
Audible from end of bed
Diastolic Quiet Easily audible Associated with
thrill
Audible without stethoscope
murmurs, all have an otherwise normal cardiovascular examination, are always systolic, often vary with posture and usually have a characteristic quality. Some murmurs are soft, short and heard only at the left sternal edge, others have a typical vibratory quality much like humming and can be quite loud. These are known as Still’s murmurs. A venous hum is also common, particularly when a child is examined standing up. It is heard beneath either clavicle and extends through systole into diastole sometimes sounding like an arterial duct. Unlike a duct, however, a venous hum disappears as a child rotates his head or is supine.
A positive diagnosis of an innocent murmur enables the examining doctor to be very reassuring with the family that the heart is structurally normal.
Investigations
Many heart conditions result in failure to thrive in infancy; therefore, height and weight should always be measured and plotted on a centile chart. Where possible, to complete the examination the child’s saturation should be measured using a pulse oximeter. When using this equipment care should be taken to ensure the child’s peripheries are warm, well perfused and the oximeter should be left in place on the child for at least 30 seconds to allow stabilisation of the reading. Measurement of the right brachial blood pressure should be made using the correctly sized cuff for the child. If coarctation is a possibility, many advocate the comparison of blood pressure measurements between arm and leg. In author’s experience he has found this comparison misleading and do not place great emphasis on its importance. If there is any suspicion of endocarditis, a urine sample should be analysed for haemolysed blood and proteinuria.
Electrocardiography
Electrocardiography is a simple noninvasive tool that records the electrical activity of the heart. A study is performed by attaching recording electrodes to specifi c sites on the skin to obtain raw recordings of cardiac electrical activity. These recordings are then processed to produce recognised “leads” that are printed out for examination. The electrical activity associated with each heart beat can be seen as a sequence of waves denoted P, Q, R, S and T (Fig. 8.1). These different leads look at the heart from different aspects allowing information to be obtained from most areas. By analysing the electrical activity of the heart, the precise heart rate and rhythm can be identifi ed, the electrical axis can be measured, as can the heights and durations of the various waves. These measurements give information about the size and thickness of the various heart chambers, areas of ischaemic or infarction, and about abnormalities of conduction that might predispose the child to arrhythmias.
Chest X-Ray
Where echo is available, a chest X-ray is not needed to make a diagnosis. However, it remains useful in assessing the severity of an abnormality and monitoring response to treatment. From a cardiac point of view, a chest X-ray provides information about the size of the heart, the pulmonary blood fl ow and about associated lung abnormalities.
An increased cardiothoracic ratio (over 0.6 in infancy and 0.55 in childhood) suggests enlargement of one or more chambers of the heart indicating volume loading or reduced function. Serial assessments of the cardiothoracic ratio may, therefore, provide information regarding change in severity of the problem over time or the effect of treatment.
Assessment of the pulmonary vasculature may provide information on the volume of pulmonary blood fl ow. This may be useful when assessing the signifi cance of a moderate sized left to right cardiac shunt in a child; plethoric lung fi elds would indicate excessive pulmonary blood fl ow and, therefore, a haemodynamically signifi cant abnormality. In a cyanosed newborn infant, oligaemic lung fi elds might suggest a cardiac lesion resulting in reduced pulmonary blood fl ow such as tetralogy of Fallot or PAt.
The fi nding of associated lung abnormalities can give useful information about the signifi cance of the heart lesion or otherwise. Collapse of the left lower lobe is particularly common in children with left atrial enlargement, aspiration due to gastro-oesophageal refl ux disease is more common in breathless infants with cardiac problems and the fi nding of vertebral or rib abnormalities may suggest a generalised syndromic abnormality rather than an isolated cardiac problem.
Echocardiography
Echocardiography is essentially ultrasound of the heart. The differences compared with conventional ultrasound are the
hardware and software settings that are confi gured to view the rapidly moving structures within the heart. Four main types of imaging are used that look at various aspects of cardiac function.
1. Two-dimensional or cross-sectional echo produces conventional ultrasound-type images of the heart structures moving in real time (Fig. 8.2). This modality facilitates accurate anatomical diagnosis of heart conditions by imaging how the various structures relate to each other.
2. M-mode echo takes a single line through the heart and plots all the information obtained against a time axis (Fig. 8.3). This mode is used for measurements and calculations particularly concerning ventricular function. 3. Doppler ultrasound measures the velocity of blood moving
through the heart and great vessels. Using this data, it is possible to estimate pressure differences at various points in the heart such as across the aortic, pulmonary, mitral and tricuspid valves, a VSD or PDA and thus measure
the severity of any narrowing or estimate the absolute pressure in a particular chamber.
4. Colour Doppler imaging superimposes Doppler infor- mation on blood fl ow on the moving 2-dimensional image of the heart. The technique uses different colours to represent both the direction of blood fl ow and its velocity (Fig. 8.4). This mode allows identifi cation of valve leaks or heart defects that might not be seen on 2-dimensional imaging alone.
Echocardiography is now the mainstay of paediatric cardiac diagnosis. The availability of high quality machines at relatively low cost has expanded the routine use of this valuable technique such that it is now often undertaken by specialists in neonatology and general paediatrics as well as paediatric cardiologists.
Cardiac Catheter
Cardiac catheterisation is both a diagnostic and treatment tool. Long thin plastic tubes (catheters) are introduced into a vein or artery and threaded though the various chambers of the heart. Direct pressure and oxygen saturation measurements are taken and radio-opaque contrast is injected into the heart to outline various structures and abnormalities. This technique has evolved over recent years to permit many common cardiac anomalies to be treated using this minimally invasive approach. Suitable ASDs, patent arterial ducts, VSDs, stenotic pulmonary and aortic valves as well as aortic coarctation can all be treated by the transcatheter route using specialised techniques.
Fig. 8.2: Normal parasternal long-axis echocardiogram
Fig. 8.3: Normal M mode echocardiogram through left ventricle
Fig. 8.4: Colour fl ow Doppler echocardiogram demonstrating small