This study investigated whether recurrence of atrial fibrillation (AF) is reduced by omega-3 DHA supplementation (6g/day HiDHA in 91 adults with AF, commenced at least one month prior to electrical cardioversion), compared to a control group of 87 adults with AF.

Results: At 90 days, 39% of the patients receiving omega-3 fatty acid supplements had AF recurrence compared with 78% of the controls. Fish oil supplementation resulted in a 6-fold prolongation in median time to AF recurrence.

Omega-3 PUFA supplementation significantly reduced the recurrence of persistent AF, with or without additional antiarrhythmic drugs.d by taking omega-3 DHA supplements.

Kumar S, Sutherland F, Morton JB, Lee G, Morgan J, Wong J, Eccleston DE, Voukelatos J, Garg ML, Sparks PB. Long-term omega-3 polyunsaturated fatty acid supplementation reduces the recurrence of persistent atrial fibrillation after electrical cardioversion. Heart Rhythm. 2012; 9(4):483-91.