BGO, I'm in the same boat mate.
10 hours so far and failed medical on ectopic heart beat. Had all the tests (ecg, exercise ecg, scan, all successful) but mentioned that I had fainted twice. Both reasonable explanations to do with low blood pressure at the time, virus infection, etc.
I now have an anxious wait for the post to come back with the killer punch. I'm hopeful CAA will see it for what it is, a fluke occurrence, twice! Not sure how much a neurological report would run to, but if it isn't too much, I might consider it.