Is there a body of research that shows fish oil causes arrythmias? I found the June study from 2005 that showed people with ICDs should probably avoid Fish Oil Supplements because it seems to cause arrythmias in those with Internal Cardioverter Defibrillators. My husband has been taking Fish Oil supplements at the suggestion of his cardiologist for more than six months after a mild heart attack in which no discernable damage was done to his heart, and two stents were placed to the LAD. 10 days ago he went into v-tach and v-fib and eventual cardiac arrest while in a hospital ER, thank God. He was defibrillated once and normal sinus rhythm returned. He now has a new third stent and an ICD implanted. While researching ICDs I found the study from last Summer about avoiding fish oil supplements if you have one. WEll, what about them bringing on arrythmias in people who don't have an ICD?