A detailed history and comprehensive bedside physical examination are the starting point for clinical evaluation and provide information on patient status, ventricular pressures, volumes and contractility, valve function, and cardiac anatomy. Unfortunately, the diagnostic auscultation skills of physicians-in-training is often poor,^1-3 a situation at least in part created by the availability of modern imaging techniques. Ideally, a thorough cardiac physical examination should provide a diagnosis or limited differential diagnosis and form the basis for efficient patient evaluation.

GENERAL OBSERVATION

Several features of the patient’s appearance provide useful clues about the presence of heart disease. Infants with large left-to-right shunts or lesions associated with poor cardiac output can have failure to thrive. Plotting their weight and height measurements on growth curves frequently demonstrates crossing of percentiles in a downward direction. In such infants, weight is usually affected before height.

Cyanosis can be caused by cardiac, pulmonary, hematologic, or central nervous system disorders.⁴ Because of the characteristics of fetal hemoglobin, which produces higher oxygen saturation for a given oxygen tension, identifying subtle cyanosis in neonates is difficult.⁵ Similar challenges are present in patients with darker skin pigmentation.

In patients with congenital heart disease, extracardiac anomalies are present in approximately 20%, and specific syndromes are identified in approximately 8%.⁶ Syndromes that occur relatively frequently are listed in Table 51-1.⁷ Recognition of certain syndromes can lead to early detection of heart disease, which may not produce murmurs in the neonatal period when pulmonary vascular resistance is elevated.

VITAL SIGNS

Analysis of the vital signs provides a description of the patient’s status and information about the likelihood of a cardiac condition.

Pulse

Rate and Rhythm

The average resting heart rate varies with the patient’s age. For an infant, the value is 125; for a child it is 100; and for an adolescent, 85.⁸ Sinus tachycardia occurs in many conditions including fever, anemia, anxiety, pain, myocardial dysfunction, cardiac tamponade, hyperthyroidism, sepsis, dehydration, and pulmonary disease. Bradycardia is associated with eating disorders, hypothyroidism, heart block, well-conditioned athletes, and increased intracranial pressure. Atrial tachyarrhythmias in the pediatric age group are most commonly supraventricular tachycardia; in children this arrhythmia typically has a non-variable rate >220 bpm and is too rapid to count.

One common normal variation in heart rate in pediatrics is sinus arrhythmia, which is characterized by a faster rate during inspiration and a slower rate during expiration. This phasic pattern can sometimes be prominent. The diagnosis is made by identifying the relationship to the respiratory cycle. Premature beats can represent atrial, junctional, or ventricular premature beats. Atrial premature beats that occur during the refractory period are frequent causes of “pauses” in neonates and typically resolve in the first few weeks of life.⁹ Atrial flutter or atrial fibrillation can have a variable rhythm depending on conduction through the atrioventricular node. A specific diagnosis of rhythm abnormality can be made by reviewing an electrocardiogram.

Prominence

Prominent bounding pulses are associated with conditions that have low diastolic pressure and wide pulse pressure. Such conditions include moderate or severe aortic regurgitation, patent ductus arteriosus, aortopulmonary window, truncus arteriosus, or arteriovenous malformations. The pulsatile flow through the capillary bed can be viewed by lightly compressing the nail bed (Quincke’s pulse).¹⁰

Generalized decreased pulses most commonly reflect myocardial dysfunction associated with myocarditis or cardiomyopathy, but also can be present in cardiac tamponade, constrictive pericarditis, or obstructive lesions. Rarely, patients may have Takayasu’s arteritis, a vasculitis that affects large arteries and may result in stenosis or occlusion of the aorta and its branches.¹¹

Differential pulse strength is associated with several conditions. The most common is aortic coarctation, which typically occurs in the aortic isthmus, distal to the origin of the left subclavian artery and proximal to the insertion of the ductus arteriosus. The pulse is more prominent in the arm than the leg. In some patients, the origin of the left subclavian artery can be involved in the coarctation so that there is a differential in pulse strength between the arms. Very rarely in patients with coarctation, the right subclavian artery can arise aberrantly from the descending aorta; in this situation, the carotid pulse will be stronger than the pulses in the extremities. Another condition that can produce differential pulses is supravalvar aortic stenosis. In this condition, blood flow can be preferentially directed to the innominate artery producing asymmetric pulses in the arms (Coanda effect). Takayasu’s aortitis can also produce differential pulses if there is variable stenosis of the subclavian and iliac arteries or their branches.

Variation

Respiratory variation in pulse strength is a feature of pulsus paradoxus, a condition associated with a fall in systolic blood pressure >10 mmHg during exhalation. This pattern is a feature of cardiac tamponade but can also be seen in severe respiratory distress. Variation in pulse strength with every other beat is a feature of left ventricular dysfunction and is termed pulsus alternans. A pulse with two peaks separated by a plateau occurs in patients with obstructive left ventricular cardiomyopathy or large stroke volumes and is termed pulsus bisferiens.¹⁰

Blood Pressure

A cuff of the appropriate size is required for the accurate measurement of blood pressure. The bladder of the inflatable cuff should be wide enough to cover three-quarters of the length of the portion of the extremity where it is placed, and it should be long enough to fully encircle the extremity.¹² Values may be inaccurately elevated if the cuff is either too small or does not fit snugly around the extremity.¹⁰ Falsely elevated values may also occur if the patient is agitated or anxious (white-coat hypertension). If hypertension is detected, it is useful to repeat the measurement at the end of the examination when the patient may be more relaxed.

For assessment of coarctation of the aorta, measurements are necessary in the upper and lower extremities. As noted earlier, since the left subclavian artery can be involved in the coarctation, it is more useful to measure the blood pressure in the right arm and a leg. The systolic pressure in the lower extremity is usually 5 to 10 mmHg greater than that in the upper extremity because of a standing wave effect. If the systolic pressure in the arm is >10 mmHg greater than that in the leg, this suggests coarctation.

In most clinics, the blood pressure is measured by oscillometric methods. When assessing for pulsus paradoxus, however, the auscultation method is required. The cuff is inflated so that the pressure is approximately 20 mmHg above the systolic value. The cuff is then slowly deflated. The pressures at which the Korotkoff sound is initially detected intermittently and then consistently are noted. The difference in these values represents the pulsus paradoxicus, and is normally less than 10 mmHg.

Respiration

Tachypnea can be present in patients with large left-to-right shunts, cardiac dysfunction, or left-sided obstructive lesions, but it can also occur in patients with sepsis, pulmonary disease, or metabolic acidosis. Tachypnea can be accompanied by retractions at the intercostal or subcostal level, flaring of the alae nasi, or wheezing. Orthopnea implies elevated pulmonary venous pressure that can occur with obstructive left-sided lesions, mitral regurgitation, or cardiomyopathy.

CARDIAC EXAMINATION

A thorough examination of the heart requires evaluation of three categories: inspection, palpation, and auscultation.

Inspection

Patients with congenital heart disease associated with cardiomegaly may have a more prominent left chest created by compression of the heart against an elastic rib cage.¹³ Pectus carinatum can be associated with Marfan syndrome, whereas pectus excavatum can be associated with mitral valve prolapse. A visible apical impulse is associated with left ventricular volume overload lesions (aortic or mitral regurgitation, left-to-right shunts at the ventricular or great vessel level). A visible parasternal impulse is seen in conditions with dilated right ventricles including tetralogy of Fallot, absent pulmonary valve associated with severe pulmonary regurgitation, or Ebstein’s anomaly associated with severe tricuspid regurgitation.

Palpation

Palpation provides information about the ventricular impulse, thrills, and occasionally heart sounds. Normal left and right ventricular impulses have different characteristics in infants, children, and adolescents so that experience is required in patients with different chest sizes to appreciate normal and abnormal impulses. The left ventricular apical impulse is usually located between the fourth and fifth intercostal spaces in the left midclavicular line and is assessed by using the tips of the index and middle fingers. The impulse is located laterally and is more prominent in lesions associated with left ventricular volume overload. Patients with mesocardia have the impulse in the mid chest, and those with dextrocardia have the impulse in the right chest. The right ventricular impulse is assessed by placing the heads of the metacarpals parallel to the left side of the sternum. A prominent lift is present in lesions associated with right ventricular pressure or volume overload.

The presence of a thrill indicates a murmur of at least grade 4. By assessing the timing and location of a thrill, a likely diagnosis can be determined. Systolic thrills at the left lower sternal border are usually caused by a ventricular septal defect; this defect may be small and associated with a high-pressure gradient between the ventricles, or it may be large and associated with a significant left-to-right shunt. Occasionally, a thrill in this region is caused by tricuspid regurgitation if right ventricular pressure is elevated. Thrills associated with mitral, aortic, or pulmonary valve disease are located at the apex, right upper sternal border, or left upper sternal border, respectively. Moderate or severe aortic stenosis can also create a thrill in the suprasternal notch or over the course of the carotid artery. This finding helps to distinguish aortic from pulmonary valve stenosis. Thrills can also occur in diastole-associated with mitral stenosis, aortic regurgitation, or pulmonary regurgitation, and are located in the respective valve regions of the precordium.

A palpable S₂ occurs in conditions associated with systemic pressure in the anteriorly positioned great artery. This finding most often indicates the presence of pulmonary artery hypertension, but also can occur in patients with an anteriorly positioned aorta such as occurs in transposition of the great arteries. A palpable S₁ can occur in hyperdynamic states.¹⁰

Auscultation

Thorough auscultation requires a quiet setting without extraneous noises from other individuals, and the use of appropriate equipment. The stethoscope tubing should be no longer than 16 to 18 inches with a bore of 1/8 inch, and should have no leak from the chest piece to the ear piece.¹⁴ There should be both a bell to detect low-frequency sounds and a diaphragm for high-frequency sounds. In infants and children, a pediatric-sized diaphragm helps to localize the point of maximal intensity. Auscultation should be performed with the patient in the supine, sitting, and occasionally standing position since for many diagnoses the murmur changes with different patient posture.