Approximately 40,000 children are born in North America each year with congenital heart disease (CHD). Approximately half of these children require no therapy, because the defect is relatively minor (eg, a bicuspid aortic valve) or spontaneously heals (eg, a small ventricular septal defect). However, in the other half of these children, surgical or catheter intervention is necessary. For some of the children in this group, the CHD does not cause hypoxemia, circulatory insufficiency, or symptoms; these children typically undergo repair on an elective basis in childhood (eg, atrial septal defects or progressive valvar disease). In this group of school-age children, it has been shown that there is little to no impact on the central nervous system from either the unrepaired defect or from the effects of anesthesia, surgery, or postoperative care following the repair.1
In contrast, it is now increasingly recognized that the group of children with CHD severe enough to require surgery shortly after birth (eg, transposition of the great arteries [TGA], hypoplastic left heart syndrome [HLHS], total anomalous pulmonary venous return) or in early infancy (eg, tetralogy of Fallot, atrioventricular canal, large ventricular septal defects) are at increased risk for neurologic, behavioral, and psychological abnormalities as they mature. For the purposes of this chapter, we will discuss the findings on the group of children who require surgery in early infancy—those considered to have "complex congenital heart disease" (cCHD).
With improvements in diagnosis, surgery, and perioperative care, it is estimated that 95% of children born in 2010 with cCHD will survive into childhood and beyond. Current research discussed below suggests that approximately half will have neurologic, behavioral, psychosocial, or cognitive abnormalities. Unless there is a decrease in the prevalence of these problems, over the next 2 decades it is estimated that an additional 130,000 children will enter the U.S. school system at significant risk for educational, interpersonal, and, ultimately, occupational impairment (Figure 11-1).
Scope of the problem. Approximately 14,000 infants born each year are at risk for neurodevelopmental impairment secondary to complex congenital heart disease (CHD) requiring intervention early in life.
Initially, it was presumed that hypoxemia, intraoperative factors, or both were the likely causes of adverse developmental outcome, but current data suggest that the factors are multiple and probably interactive. Children with cCHD have an increased risk for congenital structural central nervous system (CNS) abnormalities and presurgical white matter injury, stroke, hemorrhage, and microcephaly. About 50% have neurologic or neurobehavioral abnormalities before their first surgery, including hyper- or hypotonia, motor asymmetry, micro- or macrocephaly, jitteriness, poor state regulation, and/or a weak suck reflex. The specific cardiac defect also plays a role in subsequent developmental risk. It appears that differences in fetal blood flow and substrate delivery that occur in the presence of cCHD lead to immaturity of brain development and render term infants with cCHD ...