5.4 Cardiovascular assessment and murmurs

Introduction

Approximately 1% of infants and children in developed countries have congenital cardiac problems. The majority are from congenital cardiac abnormalities (see Chapter 5.5). Acquired diseases include myocarditis, pericarditis, cardiomyopathies and coronary vascular disease such as Kawasaki disease (see Chapters 5.6–5.8)

History

The onset of the symptoms caused by a cardiac problem will depend on the severity of the haemodynamic disturbance. A child with congenital heart disease may present at birth with cyanosis, with symptoms related to cardiac failure at days to months of age or with a murmur heard incidentally during examination. A child with an acquired cardiac problem may present at any age.

The timing and onset of symptoms should be carefully noted. Babies with cardiac failure may present with breathlessness, feeding difficulties, inability to complete feeds and poor weight gain. If cyanosis is described, it is important to determine whether it is persistent or intermittent and its relationship to crying, feeding and activity. Normal infants may appear peripherally cyanosed when cold or febrile.

Details about the pregnancy are relevant for infants with cardiac problems. There are associations with maternal diabetes (structural heart disease, transient cardiomyopathy) and with maternal lupus (congenital heart block). Teratogenic drugs during pregnancy may cause heart disease, for instance alcohol (atrial septal defect (ASD), ventricular septal defect (VSD)), amphetamines (VSD, persistent ductus arteriosus (PDA), ASD, transposition of the great arteries (TGA)) lithium (Ebstein’s abnormality), retinoic acid (conotruncal abnormalities) and valproic acid (ASD, VSD, aortic stenosis (AS), coarctation of the aorta (CoA)). Infections during pregnancy may also be implicated. Rubella is associated with PDA and peripheral pulmonary artery stenosis. Perinatal events such as fetal distress and asphyxia may cause an ischaemic insult and cardiomyopathy.

A family history of congenital heart disease or a sibling who died suddenly without clear cause found at post-mortem (e.g. undiagnosed QT syndrome), may be important. Most congenital cardiac defects are multifactorial and the risk of another sibling being affected is around 1–3%. Several diseases have an autosomal dominant pattern of inheritance, including hypertrophic obstructive cardiomyopathy (HOCM), supravalvular aortic stenosis, Marfan’s syndrome, idiopathic mitral valve prolapse and some cases of ASD and long QT.

The onset of features of cardiac disease varies with the type of lesion. Most neonates with congenital heart disease are asymptomatic at birth. Infants with duct-dependent left-sided obstructive lesions usually present in the first 2 weeks of life as the ductus arteriosus closes. Cardiac output falls and shock develops. Infants with left-to-right shunting usually present after 4 weeks of age when pulmonary resistance has decreased and heart failure develops.

The pattern of breathing may provide clues. Increased work of breathing and grunting suggest left-sided obstructive lesions or respiratory illness. Effortless tachypnoea may be found with cyanotic heart disease (see Chapter 1.1).

Other features in history which suggest a cardiac cause, include recurrent respiratory infections, exercise tolerance, chest pain and episodes of palpitations or syncope.

Physical examination

Examining a child’s cardiovascular system is similar to examining that of an adult, but particular attention should be paid to palpation of the peripheral pulses and careful auscultation of the heart. As with most paediatric examinations, tact and patience are often required to maintain co-operation and elicit the signs accurately. Infants and young children may be most settled in a parent’s lap and occupied with a quiet toy or feeding. One may have to be flexible about the order of examination, taking the opportunity to auscultate during quieter moments.

A general assessment of the child comes first. Note whether the child appears well, has any dysmorphic features and assess whether growth is appropriate for age. Look at the tongue and mucous membranes for cyanosis. Central cyanosis is generalised; peripheral cyanosis occurs in areas of poor tissue perfusion, which are usually cold to touch. Examine the fingers for clubbing.

The peripheral pulses should be examined. Assess the rate, rhythm and character of the pulse. Compare the resting pulse rate to normal ranges for age (see Chapter 1.1). Variation of the heart rate with respiration (sinus arrhythmia) in children is more marked than in adults. The character of the pulse may change with a cardiac defect, surgical treatment or cardiac failure. Bounding pulses are often found in febrile children without heart disease but may be associated with patent ductus arteriosus or a systemic-pulmonary shunt for palliative treatment of cyanotic heart disease with decreased pulmonary blood flow. Reduced volume or delay of the femoral pulses compared with the right brachial pulse suggests coarctation of the aorta. Diffusely small pulses are associated with low-output cardiac failure or shock.

Blood pressure is a routine part of the cardiovascular examination in children. A cuff of the correct size should be wide enough to cover two-thirds of the length of the upper arm, be centred over the artery and have a bladder encircling at least two-thirds of the circumference of the upper arm. In general, fit the biggest cuff possible without covering the cubital fossa.

Chest examination starts with looking at the rate and work of breathing and comparing the respiratory rate to normal ranges. Evidence of previous surgery includes a sternotomy scar or less visible thoracotomy scar (from repair of coarctation, patent ductus arteriosus, pulmonary artery banding or insertion of systemic-pulmonary shunt).

The apex beat should be located and palpated for thrills. The presence of a thrill indicates that the murmur is pathological.

Auscultation of the heart starts with listening for the heart sounds, especially splitting of the second heart sound. In children, splitting is usually only audible during inspiration at the upper left border of the sternum. The absence of variation between inspiration and expiration (fixed splitting) occurs in atrial septal defects. Third heart sounds are heard in 20% of normal children. Listen for clicks in early systole (in aortic and pulmonary stenosis).

Murmurs should be assessed with regard to their:

• timing – systolic, diastolic or continuous;

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