Care of the child with heart disease can be a challenge for the primary care provider. The variety of structural defects is complex, and the effects of such defects on children range from minimal to life threatening. Specialty management techniques are evolving rapidly. More children with complex heart disease survive longer and have a better quality of life than was true even 15 years ago. While the vast majority of congenital cardiac lesions have few effects on the child’s growth and development and require late (if any) intervention, about one third of such lesions have a more significant impact on children and their families. This chapter provides an overview of general clinical problems and management issues that occur in this population, with specific emphasis on the child who requires staged surgical intervention.

The most useful way to characterize congenital heart defects is to divide them into defects that increase pulmonary blood flow, decrease pulmonary blood flow, and obstruct systemic blood flow (Display 56-1). Additionally, it helps to know which defects will support a two-ventricle repair and which will require a staged, single-ventricle approach. This classification is far more helpful than classifying defects as cyanotic or acyanotic, because cyanosis is associated with a variety of defects at different physiologic stages. This categorization also is more helpful to the provider in anticipating symptoms and problems.

Blood flow always takes the path of least resistance. When a communicating opening (shunt) exists, blood flows from areas of higher pressure (usually the left side of the heart or aorta) to areas of lower pressure (usually the right side of the heart or the lungs). Pulmonary vascular resistance (PVR) is highest in fetal life and immediately after birth. Maximal shunting occurs once PVR reaches normal, low levels at about 1 to 3 months of age. Occasionally, increased pulmonary blood flow will impair a child’s growth or lead to an increased incidence of respiratory infections.

A large ventricular septal defect (VSD) or persistent patent ductus arteriosus may cause congestive heart failure (CHF) once PVR falls. Common atrioventricular canal defects always produce large shunts. This anomaly also is known as an endocardial cushion defect, because it involves the endocardial cushion from which the atrioventricular valves form. Increased pulmonary blood flow causes changes in the endothelial lining and muscle wall of pulmonary vessels, thus increasing resistance to flow. By young adulthood, any large shunt will produce irreversible pulmonary vascular obstructive disease (PVOD). It is uncommon to see irreversible damage before 2 years of age.

Dilated cardiomyopathy (DCM) is characterized by ab-normally depressed contractile function that limits cardiac output. As a result, blood pools in the ventricles, causing progressive dilation. There is minimal compensatory myocardial hypertrophy. This volume load increases ventricular wall stress and oxygen consumption and decreases myocardial efficiency. These changes normally progress gradually.

Congenital heart disease (CHD) affects about 30,000 infants annually (8 in 1000 live births). It affects more children than childhood cancers or diabetes. The incidence of individual defects varies greatly; VSDs comprise about 23% of all congenital cardiac defects, while more complex lesions constitute only 1% to 2% (Forbess et al., 1995; Allan, Apfel, & Printz, 1998).

With earlier diagnosis, sometimes in fetal life, and the trend toward early, complete repair, chronic hypoxemia and pulmonary vascular disease have become much less common in children with CHD. For example, the infant with Tetralogy of Fallot (TET or TOF), the most common cyanotic cardiac defect, once underwent placement of a palliative shunt in the first months or years of life. Such a child was then at risk for hypercyanotic spells, delayed growth, and neurologic events until definitive surgical correction could be done, usually after age 5 to 6 years. Today, these infants undergo definitive repair in the second half of their first year—sooner if hypercyanotic spells develop. Classic “TET spells” now are seen rarely.

Children whose atrial septal defects must be closed can now have device occlusion during cardiac catheterization, rather than undergoing open-heart surgery. Many complex defects, such as transposition of the great arteries (TGA), which accounts for 5% to 7% of all CHD, and truncus arteriosus, which accounts for 1.4% of all CHD, now are repaired before the newborn leaves the hospital (Spicer, 1994; Garson et al., 1997).

Of most concern to the clinician are patients who require medical management of CHF before surgery, children with DCM, and the growing population with a variety of defects whose surgical options cannot provide two functioning ventricles.
These children require staged surgical palliation to a single-ventricle physiology or cardiac transplant to survive beyond the neonatal period. The best known of these defects is hypoplastic left heart syndrome (HLHS) (Johnston, Chinnock, Zuppan, et al., 1997; Caplan, Cooper, Garcia-Prats, & Brody, 1996; Bove & Lloyd, 1996; Forbess et al., 1995). HLHS is the fourth most common congenital cardiac defect, occurring in 7.4% of all CHD live births; the incidence is much higher if those who die during fetal development are included. HLHS is the most common form of congenital single ventricle (Allan, 1998; Chang, Hanley, Wernovsky, & Wessel, 1998; Garson et al., 1997; Zahka, 1993).

The exact prevalence of DCM in children is unknown. Hypertrophic cardiomyopathy accounts for 20% to 30% of all pediatric cardiomyopathy. DCM may be a result of structural or electrical cardiac abnormalities or may follow acute myocarditis, but 85% to 90% of DCM seen in the pediatric population is idiopathic. Familial DCM accounts for about one third of these cases. Autosomal dominant transmission is most common (Garson et al., 1997). Acquired DCM is the ultimate complication of single ventricle physiology. Heart transplant is the only “curative” treatment.

Well child visits for the child with a known cardiac disorder should include assessment of common indicators of cardiac compromise. The most strenuous activity for infants is feeding. The infant’s daily average number of ounces of formula or episodes of breastfeeding should be noted. Frequent vomiting or diarrhea may represent decreased gut perfusion. Questions for the parents related to feeding include the following:

Other issues to explore are as follows:

The provider can question the older child and adolescent directly about chest pain, dizziness, or syncope. While uncommon even in this population, these symptoms can indicate serious decompensation. Older children and adolescents should be asked about palpitations and tachycardia (“heart racing”).

The provider should ask about the use of over-the-counter medications and herbal remedies. If the provider is open to alternative therapies, he or she usually can obtain honest information from families. The provider should ask about regular dental visits and the use of subacute bacterial endocarditis (SBE) prophylaxis.

Common physical findings for many defects appear in Table 56-1. Specialized factors in the physical examination of children with large shunts, partially repaired defects, or cardiomyopathy are noted here.

The degree of cyanosis should be observed, as should respiratory rate and work of breathing while the child is undisturbed. Precordial activity is noted; the precordium is palpated for thrill and apical impulse. Heart sounds are auscultated before other physical examination. The characteristics of S₁ and S₂ are noted, as are any murmurs, clicks, or rubs. A gallop rhythm suggests increased failure.

Like all children, those with CHD may have intermittent innocent murmurs. Both physiologic and pathologic murmurs may change in intensity and duration when cardiac output is increased, such as in fever, anxiety, exercise, or agitation.

The lungs should be clear. Rales are rarely heard in infants and young children with pulmonary edema. Tachypnea is a better indicator of increased interstitial lung fluid. Mild to marked intercostal retractions may be seen.

The extremities are examined for clubbing, and peripheral pulses are palpated. Capillary refill and liver size are assessed. A liver that is enlarged because of CHF has a soft edge and cannot be pushed under the rib margin.

Weight and oxygen saturation are obtained. In infants and toddlers, blood pressure is best evaluated after clinical examination. Automated equipment is satisfactory for screening, but accurate pressures require auscultation (Gessner & Victoria, 1993).

The examination of patients with DCM should focus on indicators of decreased cardiac output (skin temperature, pallor, peripheral pulses) and right heart volume overload (liver size, tachypnea, lung sounds, increased work of breathing). Neck vein distention and peripheral edema may be seen in older children and adolescents. As noted earlier, lung auscultation rarely reveals rales in infants and small children, even in frank pulmonary edema, but rales may be heard in older children.

Palpation of the precordium may reveal a displaced apical impulse. Heart sounds may be muffled, or there may be a third heart sound (gallop rhythm). DCM usually does not produce a murmur until the left ventricle is dilated sufficiently to distort the mitral valve annulus, producing mitral regurgitation.

Echocardiography is valuable in confirming and providing a detailed picture of clinical diagnoses. It has virtually eliminated the need for invasive cardiac catheterization as a diagnostic aid. Studies in children between 6 and 36 months of age usually require sedation for adequate imaging. Some lesions (eg, aortic stenosis) require serial evaluation and more frequent studies than lesions that progress more slowly or not at all.

Magnetic resonance imaging (MRI) has become increasingly important in the follow-up of coarctation and other aortic arch problems that are less easily imaged by echocardiography as the child grows. Children with TET, pulmonary atresia, or systemic-pulmonary shunts may need serial lung perfusion scans to assess growth of the branch pulmonary vasculature and to guide interventions.

A 24-hour rhythm recording (Holter monitor) may be done annually or biennially for children whose defects or surgical repairs pose a risk of late arrhythmias. This can be obtained prior to the cardiology visit so that results are available for discussion. The provider should discuss timing with the cardiology team. Someone skilled in pediatric rhythm analysis should provide rhythm interpretation. For children with suspected arrhythmias, a baseline 12-lead electrocardiogram (ECG) and if possible, a 12-lead ECG obtained during any “events” are useful at the cardiology visit. Holter monitoring is less useful as a diagnostic tool for supraventricular tachycardia (SVT) because events usually are infrequent. Event monitors that can be triggered when symptoms appear are more helpful. Holter monitoring is more useful in the evaluation of bradycardia to assess heart rate variability.

Laboratory tests are not required routinely. If anemia is a concern, the clinician should monitor hemoglobin and hematocrit. Children on angiotensin-converting enzyme (ACE) inhibitors should have a complete blood count, electrolytes, blood urea nitrogen, and creatinine done annually to check for evidence of renal failure and electrolyte disturbance. Anemia status also should be assessed. Drug therapy usually is evaluated by clinical response. The clinician should consult with the cardiology team to determine if regular serum drug levels should be obtained.

For children undergoing staged repair, the provider should assess oxygen saturation using pulse oximetry at each well child visit. Determine whether the cardiology team prefers a specific extremity to be used.

Cardiac stress testing has several uses. The cardiologist may clear individuals with minor defects for competitive sports based on their cardiovascular response to exercise. Testing can identify a hypertensive response to exercise or dynamic recoarctation late after coarctation repair. Some defects, such as aortic stenosis, are more hemodynamically significant during exercise. Testing rarely provokes arrhythmias in individuals with SVT and normal hearts and is not useful in the initial diagnostic evaluation of tachycardia. A team familiar with pediatric cardiac stress testing should perform and interpret testing.

Regular follow-up with a pediatric cardiologist is mandatory for virtually all children with heart disease. Of course, children with progressive lesions or who have undergone some type of intervention obviously will require follow-up. More benign lesions, such as small VSDs or pulmonary stenoses, also require specialized follow-up but less frequently. The cardiologist will be most aware of subtle cardiovascular changes, common and uncommon risks of lesions during development, and new management options. The cardiologist is best able to evaluate and manage the child clinically, avoiding extensive and unnecessary testing. A key premise of pediatric cardiology is that intervention should precede the development of clinical symptoms. An overview of common defects and their management is presented in Table 56-1.