Ventricular tachycardia (VT) and ventricular fibrillation (VF) are common causes of the 300,000 sudden deaths occurring in the United States each year. Most of these victims have associated heart disease, most commonly coronary artery disease. Populations consuming considerable quantities of fish and marine mammals have lower than expected mortality rates from coronary disease. Interventional and observational trials have indicated that fatty fish consumption decreases the death rate from coronary artery disease, in part by reducing the number of sudden deaths. Animal and tissue culture studies both support the hypothesis that these beneficial effects are from the antiarrhythmic properties of n-3 long chained polyunsaturated fatty acids (eicosapentaenoic and docosahexaenoic acids).