The role of carnitine in myocardial dysfunction.

L-Carnitine (carnitine) may have a role in the treatment of various cardiac disorders because of its actions on cardioprotection from hypoxia and oxidative stress. Studies on the role of carnitine administration to patients with myocardial infarction (MI), angina, and congestive heart failure generally have been positive. In general, treatment with carnitine (1.5 to 6 g/d for up to 1 year) results in a beneficial effect of fewer deaths and less heart failure when administered to patients after MI. Compared with placebo, carnitine use resulted in smaller increases in left ventricular end-systolic and end-diastolic volumes over time. In shorter term studies (1 to 3 months), carnitine therapy may have positive effects on symptoms of heart failure and angina in the post-MI period. Carnitine also seems to improve exercise tolerance and oxygen consumption in moderate to severe heart failure. Only preliminary results are available; results of a long-term (3-year) study should be reported soon. Studies specific to the dialysis population have generally shown that carnitine may have a beneficial effect on a number of cardiac parameters. Because cardiac disease is the most common form of death in patients with end-stage renal disease, these findings may be particularly important for this population. Moreover, because the relationship between conventional cardiac risk factors and cardiac disease is less clear in this population, the role of therapies that address pathological states specific to the dialysis population is worthy of study. Because a dialysis-related carnitine disorder is common among these patients, L-carnitine supplementation would be among these specific therapies.