Aberrations in Carnitine Homeostasis in Congenital Heart Disease With Increased Pulmonary Blood Flow

Infants with congenital heart disease and increased pulmonary blood flow have altered carnitine homeostasis that is associated with clinical outcomes; and L-carnitine treatment will attenuate these alterations and improve clinical outcomes. The investigators will pilot a trial assessing the safety and pharmacokinetics of perioperative IV L-carnitine administration in these patients. To this end, a pilot clinical trial is proposed. Infants with ventricular septal defects or atrioventricular septal defects undergoing complete surgical repair will receive L-carnitine (25, 50, or 100 mg/kg, IV) just prior to cardiopulmonary bypass (CPB) and 2hr after CPB. Carnitine levels will be measured before CPB, and before and 0.5, 1.5, 3, 5, 9, 12, and 24h after the second dose. The safety, pharmacokinetic profile, feasibility, and effect of L-carnitine administration on biochemical parameters, as well as clinical outcomes will be determined. The investigators expect this pilot to provide the data needed to proceed with a placebo-based randomized, controlled, trial.