History

A comprehensive cardiac history starts with details of the perinatal period including the presence of cyanosis, respiratory distress, or prematurity. Maternal complications such as gestational diabetes, teratogenic medications, systemic lupus erythematosus, or substance abuse can be associated with cardiac problems. If cardiac symptoms began during infancy, the timing of the initial symptoms should be noted to provide important clues about the specific cardiac condition.

Many of the symptoms of heart failure in infants and children are age specific. In infants, feeding difficulties are common. Inquiry should be made about the frequency of feeding and either the volume of each feeding or the time spent on each breast. An infant with heart failure often takes less volume per feeding and becomes dyspneic or diaphoretic while sucking. After falling asleep exhausted, the baby, inadequately fed, will awaken for the next feeding after a brief time. This cycle continues around the clock and must be carefully differentiated from colic or other feeding disorders. Additional symptoms and signs include those of respiratory distress: rapid breathing, nasal flaring, cyanosis, and chest retractions. In older children, heart failure may be manifested as exercise intolerance, difficulty keeping up with peers during sports or need for a nap after coming home from school, poor growth, or chronic abdominal complaints. Eliciting a history of fatigue in an older child requires questions about age-specific activities, including stair climbing, walking, bicycle riding, physical education class, and competitive sports; information should be obtained regarding more severe manifestations such as orthopnea and nocturnal dyspnea.

Cyanosis at rest is often overlooked by parents; it may be mistaken for a normal individual variation in color. Cyanosis during crying or exercise, however, is more often noted as abnormal by observant parents. Many infants and toddlers turn “blue around the lips” when crying vigorously or during breath-holding spells; this condition must be carefully differentiated from cyanotic heart disease by inquiring about inciting factors, the length of episodes, and whether the tongue and mucous membranes also appear cyanotic. Newborns often have cyanosis of their extremities (acrocyanosis) when undressed and cold; this response to cold must be carefully differentiated from true cyanosis, where the mucous membranes are also blue.

Chest pain is an unusual manifestation of cardiac disease in pediatric patients, although it is a frequent cause for referral to a pediatric cardiologist, especially in adolescents. Nonetheless, a careful history, physical examination, and, if indicated, laboratory or imaging tests will assist in identifying the cause of chest pain (Table 416-1). For patients with some forms of repaired congenital heart disease or those with a history of Kawasaki disease (Chapter 438.1); however, chest pain should be evaluated carefully for a coronary etiology.

Cardiac disease may be a manifestation of a known congenital malformation syndrome with typical physical findings (Table 416-2) or a manifestation of a generalized disorder affecting the heart and other organ systems (Table 416-3). Extracardiac malformations may be noted in 20-45% of infants with congenital heart disease. Between 5 and 10% of patients have a known chromosomal abnormality; the importance of genetic evaluation will increase as our knowledge of specific gene defects linked to congenital heart disease increases.

Table 416-2 CONGENITAL MALFORMATION SYNDROMES ASSOCIATED WITH CONGENITAL HEART DISEASE

ASD, atrial septal defect; AV, aortic valve; PDA, patent ductus arteriosus; PS, pulmonary stenosis; TOF, tetralogy of Fallot; VSD, ventricular septal defect.

* Conotruncal includes TOF, pulmonary atresia, truncus arteriosus, and transposition of great arteries.

Table 416-3 CARDIAC MANIFESTATIONS OF SYSTEMIC DISEASES

LEOPARD, multiple lentigines, electrocardiographic conduction abnormalities, ocular hypertelorism, pulmonary stenosis, abnormal genitals, retardation of growth, sensorineural deafness.

A careful family history may also reveal early (at age less than 50 yr) coronary artery disease or stroke (suggestive of familial hypercholesterolemia or thrombophilia), sudden death (suggestive of cardiomyopathy or familial arrhythmic disorder), generalized muscle disease (suggestive of one of the muscular dystrophies, dermatomyositis, or familial or metabolic cardiomyopathy), or first-degree relatives with congenital heart disease.

General Physical Examination

A general assessment of the patient is always the first part of the examination, with specific attention directed toward the presence of cyanosis, abnormalities in growth, chest wall abnormalities, and any evidence of respiratory distress. Although the murmur may be the most prominent part of the overall examination, any murmur must be placed in context of other physical findings. Frequently, associated findings, such as the quality of the pulses, the presence of a ventricular heave or thrill, or the splitting of the second heart sound, provide important clues to a specific cardiac diagnosis.

Accurate measurement of height and weight and plotting on a standard growth chart are important because both cardiac failure and chronic cyanosis can result in failure to thrive. Growth failure is manifested predominantly by poor weight gain; if length or head circumference is also affected, additional congenital malformations or metabolic disorders should be suspected.

Mild cyanosis may be too subtle for early detection, and clubbing of the fingers and toes is not usually manifested until late in the 1st yr of life, even in the presence of severe arterial oxygen desaturation. Cyanosis is best observed over the nail beds, lips, tongue, and mucous membranes. Differential cyanosis, manifested as blue lower extremities and pink upper extremities (usually the right arm), is seen with right-to-left shunting across a ductus arteriosus in the presence of coarctation or an interrupted aortic arch. Circumoral cyanosis or blueness around the forehead may be the result of prominent venous plexuses in these areas, rather than decreased arterial oxygen saturation. The extremities of infants often turn blue when the infant is unwrapped and cold (acrocyanosis), and this condition can be distinguished from central cyanosis by examination of the tongue and mucous membranes.

Heart failure in infants and children usually results in some degree of hepatomegaly and occasionally splenomegaly. The sites of peripheral edema are age dependent. In infants, edema is usually seen around the eyes and over the flanks, especially on initially waking. Older children and teenagers manifest both periorbital edema and pedal edema. A not uncommon initial complaint in these older patients is that their clothes no longer fit.

The heart rate of newborn infants is rapid and subject to wide fluctuations (Table 416-4). The average rate ranges from 120 to 140 beats/min and may increase to 170+ beats/min during crying and activity or drop to 70-90 beats/min during sleep. As the child grows older, the average pulse rate decreases and may be as low as 40 beats/min at rest in athletic adolescents. Persistent tachycardia (>200 beats/min in neonates, 150 beats/min in infants, or 120 beats/min in older children), bradycardia, or an irregular heartbeat other than sinus arrhythmia requires investigation to exclude pathologic arrhythmias (Chapter 429). Sinus arrhythmia can usually be distinguished by the rhythmic nature of the heart rate variations, occurring in concert with the respiratory cycle, and with a P wave before every QRS complex.

Careful evaluation of the character of the pulses is an important early step in the physical diagnosis of congenital heart disease. A wide pulse pressure with bounding pulses may suggest an aortic runoff lesion such as patent ductus arteriosus, aortic insufficiency, an arterial-venous communication, or increased cardiac output secondary to anemia, anxiety, or conditions associated with increased catecholamine or thyroid hormone secretion. The presence of diminished pulses in all extremities is associated with pericardial tamponade, left ventricular outflow obstruction, or cardiomyopathy. The radial and femoral pulses should always be palpated simultaneously. Normally, the femoral pulse should be appreciated immediately before the radial pulse. In infants with coarctation of the aorta, the femoral pulses may be decreased. However, in older children with coarctation of the aorta, blood flow to the descending aorta may channel through collateral vessels and results in the femoral pulse being palpable but delayed until after the radial pulse (radial-femoral delay).

Blood pressure should be measured in the legs as well as in the arms to be certain that coarctation of the aorta is not overlooked. Palpation of the femoral or dorsalis pedis pulse, or both, is not reliable alone to exclude coarctation. In older children, a mercury sphygmomanometer with a cuff that covers approximately two thirds of the upper part of the arm or leg may be used for blood pressure measurement. A cuff that is too small results in falsely high readings, whereas a cuff that is too large records slightly decreased pressure. Pediatric clinical facilities should be equipped with 3, 5, 7, 12, and 18 cm cuffs to accommodate the large spectrum of pediatric patient sizes. The 1st Korotkoff sounds indicate systolic pressure. As cuff pressure is slowly decreased, the sounds usually become muffled before they disappear. Diastolic pressure may be recorded when the sounds become muffled (preferred) or when they disappear altogether; the former is usually slightly higher and the latter slightly lower than true diastolic pressure. For lower extremity blood pressure determination, the stethoscope is placed over the popliteal artery. Ordinarily, the pressure recorded in the legs with the cuff technique is about 10 mm Hg higher than that in the arms.

In infants, blood pressure can be determined by auscultation, palpation, or an oscillometric (Dinamap) device that, when properly used, provides accurate measurements in infants as well as older children.

Blood pressure varies with the age of the child and is closely related to height and weight. Significant increases occur during adolescence, and many temporary variations take place before the more stable levels of adult life are attained. Exercise, excitement, coughing, crying, and struggling may raise the systolic pressure of infants and children as much as 40-50 mm Hg greater than their usual levels. Variability in blood pressure in children of approximately the same age and body build should be expected, and serial measurements should always be obtained when evaluating a patient with hypertension (Figs. 416-1 and 416-2).

Figure 416-1 A, Age-specific percentiles of blood pressure (BP) measurements in boys from birth to 12 mo of age. B, Age-specific percentiles of BP measurements in girls from birth to 12 mo of age. C, Age-specific percentiles of BP measurements in boys 1-13 yr of age. D, Age-specific percentiles of BP measurements in girls 1-13 yr of age; Korotkoff phase IV (K4) used for diastolic BP. Dias, diastolic; Ht, height; Perc, percentile; Sys, systolic; Wt, weight.

(From [no authors listed]: Report of the Second Task Force on Blood Pressure Control in Children—1987. National Heart, Lung, and Blood Institute, Bethesda, MD, Pediatrics 79:1–25, 1987.

Figure 416-2 A, Age-specific percentiles of blood pressure (BP) measurements in boys 13-18 yr of age. B, Age-specific percentiles of BP measurements in girls 13-18 yr of age; Korotkoff phase V (K5) used for diastolic BP. Dias, diastolic; Ht, height; Perc, percentile; Sys, systolic; Wt, weight.

(From [no authors listed]: Report of the Second Task Force on Blood Pressure Control in Children—1987. National Heart, Lung, and Blood Institute, Bethesda, MD, Pediatrics 79:1–25, 1987.

Though of little use in infants, in cooperative older children, inspection of the jugular venous pulse wave provides information about central venous and right atrial pressure. The neck veins should be inspected with the patient sitting at a 90-degree angle. The external jugular vein should not be visible above the clavicles unless central venous pressure is elevated. Increased venous pressure transmitted to the internal jugular vein may appear as venous pulsations without visible distention; such pulsation is not seen in normal children reclining at an angle of 45 degrees. Because the great veins are in direct communication with the right atrium, changes in pressure and the volume of this chamber are also transmitted to the veins. The one exception occurs in superior vena cava obstruction, in which venous pulsatility is lost.

Cardiac Examination

The heart should be examined in a systematic manner, starting with inspection and palpation. A precordial bulge to the left of the sternum with increased precordial activity suggests cardiac enlargement; such bulges can often best be appreciated by having the child lay supine with the examiner looking up from the child’s feet. A substernal thrust indicates the presence of right ventricular enlargement, whereas an apical heave is noted with left ventricular enlargement. A hyperdynamic precordium suggests a volume load such as that found with a large left-to-right shunt, although it may be normal in a thin patient. A overly silent precordium with a barely detectable apical impulse suggests pericardial effusion or severe cardiomyopathy, but may be normal in an obese patient.

The relationship of the apical impulse to the midclavicular line is also helpful in the estimation of cardiac size: the apical impulse moves laterally and inferiorly with enlargement of the left ventricle. Right-sided apical impulses signify dextrocardia, tension pneumothorax, or left-sided thoracic space-occupying lesions (e.g., diaphragmatic hernia).

Thrills are the palpable equivalent of murmurs and correlate with the area of maximal auscultatory intensity of the murmur. It is important to palpate the suprasternal notch and neck for aortic bruits, which may indicate the presence of aortic stenosis or, when faint, pulmonary stenosis. Right lower sternal border and apical systolic thrills are characteristic of ventricular septal defect and mitral insufficiency, respectively. Diastolic thrills are occasionally palpable in the presence of atrioventricular valve stenosis. The timing and localization of thrills should be carefully noted.

Auscultation is an art that improves with practice. The diaphragm of the stethoscope is placed firmly on the chest for high-pitched sounds; a lightly placed bell is optimal for low-pitched sounds. The physician should initially concentrate on the characteristics of the individual heart sounds and their variation with respirations and later concentrate on murmurs. The patient should be supine, lying quietly, and breathing normally. The 1st heart sound is best heard at the apex, whereas the 2nd heart sound should be evaluated at the upper left and right sternal borders. The 1st heart sound is caused by closure of the atrioventricular valves (mitral and tricuspid); the 2nd sound is caused by closure of the semilunar valves (aortic and pulmonary) (Fig. 416-3). During inspiration, the decrease in intrathoracic pressure results in increased filling of the right side of the heart, which leads to an increased right ventricular ejection time and thus delayed closure of the pulmonary valve; consequently, splitting of the 2nd heart sound increases during inspiration and decreases during expiration.

Figure 416-3 Idealized diagram of the temporal events of a cardiac cycle.

Often, the 2nd heart sound seems to be single during expiration. The presence of a normally split 2nd sound is strong evidence against the diagnosis of atrial septal defect, defects associated with pulmonary arterial hypertension, severe pulmonary valve stenosis, aortic and pulmonary atresia, and truncus arteriosus. Wide splitting is noted in atrial septal defect, pulmonary stenosis, Ebstein anomaly, total anomalous pulmonary venous return, and right bundle branch block. An accentuated pulmonic component of the 2nd sound with narrow splitting is a sign of pulmonary hypertension. A single 2nd sound occurs in pulmonary or aortic atresia or severe stenosis, truncus arteriosus, and, often, transposition of the great arteries.

A 3rd heart sound is best heard with the bell at the apex in mid-diastole. A 4th sound occurring in conjunction with atrial contraction may be heard just before the 1st heart sound in late diastole. The 3rd sound may be normal in an adolescent with a relatively slow heart rate, but in a patient with the clinical signs of heart failure and tachycardia, it may be heard as a gallop rhythm and may merge with a 4th heart sound, a finding known as a summation gallop. A gallop rhythm is attributed to poor compliance of the ventricle, and exaggeration of the normal 3rd sound is associated with ventricular filling.

Ejection clicks, which are heard in early systole, are usually due to a mildly to moderately stenotic aortic or pulmonary valve or to a dilated ascending aorta or pulmonary artery. They are heard so close to the 1st heart sound that they may be mistaken for a split 1st sound. Aortic ejection clicks are best heard at the left middle to right upper sternal border and are constant in intensity. They occur in conditions in which the aortic valve is stenotic or the aorta is dilated (tetralogy of Fallot, truncus arteriosus). Pulmonary ejection clicks, which are associated with mild to moderate pulmonary stenosis, are best heard at the left middle to upper sternal border and vary with respirations, often disappearing with inspiration. Split 1st heart sounds are usually heard best at the lower left sternal border. A midsystolic click heard at the apex, often preceding a late systolic murmur, suggests mitral valve prolapse.

Murmurs should be described according to their intensity, pitch, timing (systolic or diastolic), variation in intensity, time to peak intensity, area of maximal intensity, and radiation to other areas. Auscultation for murmurs should be carried out across the upper precordium, down the left or right sternal border, and out to the apex and left axilla. Auscultation should also always be performed in the right axilla and over both sides of the back. Systolic murmurs are classified as ejection, pansystolic, or late systolic according to the timing of the murmur in relation to the 1st and 2nd heart sounds. The intensity of systolic murmurs is graded from I to VI: I, barely audible; II, medium intensity; III, loud but no thrill; IV, loud with a thrill; V, very loud but still requiring positioning of the stethoscope at least partly on the chest; and VI, so loud that the murmur can be heard with the stethoscope off the chest. In patients who have undergone prior heart surgery, a murmur of grade IV or greater may be heard in the absence of a thrill.

Systolic ejection murmurs start a short time after a well-heard 1st heart sound, increase in intensity, peak, and then decrease in intensity; they usually end before the 2nd sound. In patients with severe pulmonary stenosis, however, the murmur may extend beyond the 1st component of the 2nd sound, thus obscuring it. Pansystolic or holosystolic murmurs begin almost simultaneously with the 1st heart sound and continue throughout systole, on occasion becoming gradually decrescendo. It is helpful to remember that after closure of the atrioventricular valves (the 1st heart sound), a brief period occurs during which ventricular pressure increases but the semilunar valves remain closed (isovolumic contraction; see Fig. 416-3). Thus, pansystolic murmurs (heard during both isovolumic contraction and the ejection phases of systole) cannot be caused by flow across the semilunar valves because these valves are closed during isovolumic contraction. Pansystolic murmurs must therefore be related to blood exiting the contracting ventricle via either an abnormal opening (a ventricular septal defect) or atrioventricular (mitral or tricuspid) valve insufficiency. Systolic ejection murmurs usually imply increased flow or stenosis across one of the ventricular outflow tracts (aortic or pulmonic). In infants with rapid heart rates, it is often difficult to distinguish between ejection and pansystolic murmurs. If a clear and distinct 1st heart sound can be appreciated, the murmur is most likely ejection in nature.

A continuous murmur is a systolic murmur that continues or “spills” into diastole and indicates continuous flow, such as in the presence of a patent ductus arteriosus or other aortopulmonary communication. This murmur should be differentiated from a to-and-fro murmur, where the systolic component of the murmur ends at or before the 2nd sound and the diastolic murmur begins after semilunar valve closure (aortic or pulmonary stenosis combined with insufficiency). A late systolic murmur begins well beyond the 1st heart sound and continues until the end of systole. Such murmurs may be heard after a midsystolic click in patients with mitral valve prolapse and insufficiency.

Several types of diastolic murmurs (graded I-IV) can be identified. A decrescendo diastolic murmur is a blowing murmur along the left sternal border that begins with S₂ and diminishes toward mid-diastole. When high-pitched, this murmur is associated with aortic valve insufficiency or pulmonary insufficiency related to pulmonary hypertension. When low-pitched, this murmur is associated with pulmonary valve insufficiency in the absence of pulmonary hypertension. A low-pitched decrescendo diastolic murmur is typically noted after surgical repair of the pulmonary outflow tract in defects such as tetralogy of Fallot or in patients with absent pulmonary valves. A rumbling mid-diastolic murmur at the left middle and lower sternal border may be due to increased blood flow across the tricuspid valve, such as occurs with an atrial septal defect or, less often, because of actual stenosis of this valve. When this murmur is heard at the apex, it is caused by increased flow across the mitral valve, such as occurs with large left-to-right shunts at the ventricular level (ventricular septal defects), at the great vessel level (patent ductus arteriosus, aortopulmonary shunts), or with increased flow because of mitral insufficiency. When an apical diastolic rumbling murmur is longer and is accentuated at the end of diastole (presystolic), it usually indicates anatomic mitral valve stenosis.

The absence of a precordial murmur does not rule out significant congenital or acquired heart disease. Congenital heart defects, some of which are ductal dependent, may not demonstrate a murmur if the ductus arteriosus closes. These lesions include pulmonary or tricuspid valve atresia and transposition of the great arteries. Murmurs may seem insignificant in patients with severe aortic stenosis, atrial septal defects, anomalous pulmonary venous return, atrioventricular septal defects, coarctation of the aorta, or anomalous insertion of a coronary artery. Careful attention to other components of the physical examination (growth failure, cyanosis, peripheral pulses, precordial impulse, heart sounds) increases the index of suspicion of congenital heart defects in these cases. In contrast, loud murmurs may be present in the absence of structural heart disease, for example, in patients with a large noncardiac arteriovenous malformation, myocarditis, severe anemia, or hypertension.

Many murmurs are not associated with significant hemodynamic abnormalities. These murmurs are referred to as functional, normal, insignificant, or innocent (the preferred term). During routine random auscultation, more than 30% of children may have an innocent murmur at one time in their lives; this percentage increases when auscultation is carried out under nonbasal circumstances (high cardiac output because of fever, infection, anxiety). The most common innocent murmur is a medium-pitched, vibratory or “musical,” relatively short systolic ejection murmur, which is heard best along the left lower and midsternal border and has no significant radiation to the apex, base, or back. It is heard most frequently in children between 3 and 7 yr of age. The intensity of the murmur often changes with respiration and position and may be attenuated in the sitting or prone position. Innocent pulmonic murmurs are also common in children and adolescents and originate from normal turbulence during ejection into the pulmonary artery. They are higher pitched, blowing, brief early systolic murmurs of grade I-II in intensity and are best detected in the 2nd left parasternal space with the patient in the supine position. Features suggestive of heart disease include murmurs that are pansystolic, grade III or higher, harsh, located at the left upper sternal border, and associated with an early or midsystolic click or an abnormal 2nd heart sound.

A venous hum is another example of a common innocent murmur heard during childhood. Such hums are produced by turbulence of blood in the jugular venous system; they have no pathologic significance and may be heard in the neck or anterior portion of the upper part of the chest. A venous hum consists of a soft humming sound heard in both systole and diastole; it can be exaggerated or made to disappear by varying the position of the head, or it can be decreased by lightly compressing the jugular venous system in the neck. These simple maneuvers are sufficient to differentiate a venous hum from the murmurs produced by organic cardiovascular disease, particularly a patent ductus arteriosus.

The lack of significance of an innocent murmur should be discussed with the child’s parents. It is important to offer complete reassurance because lingering doubts about the importance of a cardiac murmur may have profound effects on child-rearing practices, most often in the form of overprotectiveness. An underlying fear that a cardiac abnormality is present may negatively affect a child’s self-image and subtly influence personality development. The physician should explain that an innocent murmur is simply a “noise” and does not indicate the presence of a significant cardiac defect. When asked, “Will it go away?” the best response is to state that because the murmur has no clinical significance, it therefore does not matter whether it “goes away.” Parents should be warned that the intensity of the murmur might increase during febrile illnesses, a time when, typically, another physician examines the child. With growth, however, innocent murmurs are less well heard and often disappear completely. At times, additional studies may be indicated to rule out a congenital heart defect, but “routine” electrocardiographic, chest roentgenographic, and echocardiographic examinations should be avoided in well children with innocent murmurs.