Prevention of cardiac sudden death by N-3 fatty acids: a review of the evidence.

The essential n-6 and n-3 polyunsaturated fatty acids can prevent ischaemia-induced ventricular fibrillation in rats, dogs and marmosets. In isolated neonatal rat cardiac myocytes, these have been shown to prevent tachyarrhythmias caused by elevated calcium concentrations, toxic levels of ouabain, a beta-adrenergic agent (isoproterenol), lysophosphatidylcholine and acylcarnitine. The antiarrhythmic effect is caused by a reduction in electrical excitability caused by partitioning of the free polyunsaturated fatty acids into the phospholipid cell membranes of the cardiac myocytes, which modulates membrane ion channels. Two clinical trials suggest they could prevent sudden cardiac death in humans.