[The "big heart" of carnitine].

Fat is the primary energy source for heart muscle. In the heart, carnitine is essential for normal fatty acid beta-oxidation and even partial deficiency could lead to organ dysfunction. Dilated cardiomyopathy is one of the cardinal manifestations of carnitine deficiency in children. We report the case of a female infant referred to our hospital at the age of 15 months with a 2-week history of dyspnea. She presented signs and symptoms of congestive heart failure. Severe cardiomegaly was seen on chest radiographs, while the echocardiogram showed a dilated and hypokinetic left ventricle with depressed systolic function, decreased fractional shortening and ejection fraction, and left atrial enlargement. Laboratory investigations showed carnitine deficiency. She needed intravenous inotropic support in association with conventional heart failure therapy. Treatment with L-carnitine was started as soon as the samples for laboratory testing were taken. Cardiac function clearly and rapidly improved while on treatment.