ekgA study appearing in the journal Circulation (2009; 120(23): 2315-21) looked at 2,174 male subjects participating in the Kuopio Ischemic Heart Disease Risk Factor Study between the ages of 42 and 60. At the start of the study the subjects were free of atrial fibrillation. The subjects were monitored for just over 17 years and in that time 240 instances of atrial fibrillation occurred. Those subjects with higher levels of EPA , DPA and DHA had a lower incidence of atrial fibrillation.