The role of L-carnitine in pediatric cardiomyopathy.

Metabolic and genetic factors underlie some forms of cardiomyopathy in childhood. A variety of inborn errors of metabolism can impair mitochondrial energy production, or beta-oxidation, in the heart and lead to myocardial dysfunction. L-Carnitine, an essential element of beta-oxidation, transports fatty acids across the mitochondrial membrane for energy production. L-Carnitine deficiency syndromes are now well described as secondary to a variety of inborn errors of metabolism and often include cardiomyopathy in the clinical picture. Despite traditional therapies for cardiomyopathy, mortality for this disorder remains at well over 50%. Review of reports of L-Carnitine supplementation studies and results from our own trial underscore the importance of its role in cardiac function and demonstrates that there is likely a subpopulation of patients with cardiomyopathy responsive to L-carnitine treatment.