Sorry to hear it. Crap, heart surgery. Heed the advice more than a couple doctors have given me, there's not an ailment known that exercise will make worse. It can only help. Somebody in here encouraged you to fish more and I whole heartedly concur with the one caveat that you tell us all about it because I love to fish but am physically prevented from doing it.
If you find a cure for A-Fib please let me know, I've got A-Fib nearly all the time. It was 106 when I first got up this morning. I think it was 102 when I measured it yesterday afternoon. In my case my blood pressure goes low from a medicine to control the A-Fib but then the A-Fib goes high from a medicine to raise my blood pressure which goes really low, sometimes into the 60s during dialysis. It's a balancing act for me. I wonder how harmful that kind of mild A-Fib is.