IRCT2013070713886N1 IRCT 2014-08-30 Tehan University of Medical Sciences Comparing the effect of fish oil on the occurrence of atrial fibrillation with placebo (olive oil) after coronary artery bypass graft surgery in patients who are undergoing CABG surgery in the rajaei heart center in 2013, a randomized clinical trial Comparing the effect of fish oil on the occurrence of atrial fibrillation with placebo (olive oil) after coronary artery bypass graft surgery in patients who are undergoing CABG surgery in the rajaei heart center in 2014, a randomized clinical trial 2014-05-22 anticipated 392 Complete https://irct.ir/trial/13624 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention. 2-3 Post coronary artery bypass graft surgery atrial fibrilation.. Intervention 1: Intervention group: 1 gr fish oil pearls containing 300mg EPA and 200 mg DHA, twice a day , given the patients at least 5 day before surgery until time of discharge. Intervention 2: Control group: 1 gr olive oil pearls , twice a day, given to the patients, at least 5 days before surgery until time of discharge.