[Anti-arrhythmia treatment using L-carnitine in acute myocardial infarct]

Carnitine, a quaternary amine (3-hydroxy-4-N-trimethylaminobutyric acid), plays an important physiologic role in fatty acid transport and metabolism as well as in energy production of the myocardial cell. L-carnitine in high doses has been postulated to have an antiarrhythmic effect and this has also been clinically proven. We studied 20 patients with acute myocardial infarction (AMI), 4-12 hours after onset of pain. The patients were randomized and treated double-blind with 5 g L-carnitine (n = 12) or placebo (n = 8) at hours 0, 12, 24, 36, and with 2 x 3 g on days 3 to 7 by intravenous infusion over 2 hours. The two groups were similar for age, sex, infarct site, maximum CPK and conventional antiarrhythmic therapy. 24-hour Holter-ECG was performed on days 1, 2 and 7 and showed no significant difference between the two groups with respect to incidence of ventricular premature beats (VPB) per hour. On the second day following AMI, however, only 4 of 12 carnitine-treated patients showed high-grade VPB (Lown IVa and IVb), in comparison with 7 of 8 patients in the placebo group. The difference is significant: p = 0.028 (Fisher's Exact Test). Carnitine was well tolerated and the efficacy demonstrated on the second day following AMI must be interpreted with caution.