Hi there I am aware for the last hour of having atrial fibriillation I am on betablockers and warfarin for it I have been going into it for short periods and out of it for short periods at a time like 5 minutes it stops and then 10 minutes later comes back my resting heart rate is 90 with palpitations coming and going. I have not had it for a while that I am concious of. the only thing I can think of is I went out for lunch with my parents today and I had 1 pint of diet coke, with macaroni cheese a cup of coffee and I had a diet coke before I went to bed. I am thinking maybe the caffeinne and the cheese every time I eat macaroni twice now I have an episode of AF.