Hang in there, DF!

I have some small insight into what you're going through. About 6-7 years ago, I was doing a lot of cardio stuff, in particular a lot on the stair climber. I felt good, but once in a while I got some palpitations where I got that "flutter" going. It probably wasn't a big deal, but the more you start thinking about how vulnerable you are and how your heart has been beating for decades... well, it just starts to cause more anxiety which in turn aggravates the situation. Although my situation was not as severe as yours, I got the same response from the medical establishment - as though I were wasting their time. In my case, because it was intermittent, it would be fine at the doctor's office, then driving home... (the broken TV syndrome). It settled down eventually after a year or two (knock on wood), but "harrowing" wasn't a strong enough word.

Good luck and try to relax!

-Jim