n-3 Polyunsaturated fatty acids and their effect on cardiac mortality

Cardiac mortality is mainly caused by fatal cardiac arrhythmias and acute or chronic pump failure. Epidemiological studies and four intervention trials with n-3 polyunsaturated fatty acids (PUFA) clearly show that n-3 PUFA consistently reduce cardiac mortality but not cardiac morbidity, specifically myocardial infarction, indicating that n-3 PUFA may be protective through anti-arrhythmic effects. In support of this notion, in vitro studies in neonatal tat cardiac myocytes as well as animal studies reveal that n-3 PUFA protect from potentially fatal cardiac arrhythmias by reducing cardiac myocyte excitability. Preliminary trials in man further indicate that n-3 PUFA may have anti-arrhythmic effects in humans, although the definite proof for their protection from fatal arrhythmias in high risk patients is still missing. Increased consumption of n-3 PUFA is now recommended by the American Heart Association. Given that further evidence of the anti-arrhythmic effects of n-3 PUFA will accumulate, a way to quickly and safely administer n-3 PUFA to high risk patients such as those suffering from acute myocardial infarction warrants further investigation. (C) 2002, Elsevier Science Ltd. All rights reserved.