Pixie, I'm amazed that doctors would downgrade a-fib by said it's "just" anything. I have had it, and it is considered serious and occasionally life threatening. Mine is under control with Propanalol, a low dose of 5 mg 3 times a day. Many people take more but that is enough for me. Most of my ER visits before getting it under control, for a few years, were for a-fib. The medics would always find it (verify it) but sometimes it left before I got to the ER. The first two times I had it, however, it lasted for many hours, and they said it was due to low potassium. I always test low in potassium unless I take 20 MEQ a day. Prior to getting A-fib, I had tachycardia attacks due to having Porphyria, another disease which is not auto-immune but is genetic. These were a big problem most of my life, starting at age 17. Not dx'd as anything but emotional strain for decades, finally got several dx's as I reached menopause and the poor old bod just about gave up trying.