Before Christmas, I had a cup of quite strong coffee, which set my AF off almost continuously for a few weeks. It made me wonder if the tea I was drinking might have an influence on it (I do drink loads of tea). I changed to decaf and within a couple days had NO AF. Since then, I have stuck to decaf and have only had the odd bit of missed beats since. Feeling so much better, can walk more, climb stairs etc.
I do hope that this post helps some of you.