Energy metabolism in infants with congenital heart disease

Failure to thrive is common in children with congenital heart disease and influences the metabolic response to injury and outcome after corrective cardiac surgery. Energy imbalance is a major contributing factor. However, the published literature is difficult to interpret as studies generally involve small patient numbers with a diverse range of types and severity of cardiac lesions and genetic and/or prenatal factors. The age and time of corrective surgery affects the potential for nutritional recovery. Although the immediate postoperative period is characterized by a hypermetabolic state, low total and resting energy expenditure are reported within 24 h of surgery. After 5 d, resting energy expenditure returns to preoperative levels. Significant improvements in weight and growth occur within months after corrective surgery. However, limited postoperative recovery in nutritional status and growth occurs in infants with a low birth weight, intellectual deficit, or residual malformation. Further studies are needed to inform the timing of corrective cardiac surgery to maximize nutritional outcomes and to identify those infants who may benefit from aggressive preoperative nutrition support.