Effect of fish oil on heart rate variability in survivors of myocardial infarction: a double blind randomised controlled trial

Marine n-3 polyunsaturated fatty acids may protect against ischaemic heart disease.1 In the diet and reinfarction trial patients with an acute myocardial infarction advised to eat fish rich in n-3 polyunsaturated fatty acids had a 29% reduction in two year all cause mortality compared with controls.2 The authors hypothesised that dietary n-3 polyunsaturated fatty acids might reduce malignant ventricular arrhythmias and sudden cardiac death, as reported in animals.3 We investigated a possible antiarrhythmic effect of dietary n-3 polyunsaturated fatty acids in survivors of myocardial infarction. Patients were eligible for study if they had been discharged from the department of cardiology at Aalborg Hospital between November 1991 and August 1993 after a myocardial infarction and had a ventricular ejection fraction below 0.40. We excluded patients aged over 75, patients with pacemakers or permanent tachyarrhythmias, and those with serious non-cardiac disease. Eighty one patients fulfilled the inclusion criteria and 55 gave informed consent to a double blind placebo controlled trial. Patients were randomly …