"So I'm waiting for a procedure known as an ablation where they burn away the circuits that are causing the problem, although the heart specialist that is dealing with me now wants to fit a pacemaker so that he can get my resting heart rate up first...
"
I can't comment on how this effects your being able to fly or the medical tests involved etc but, fwiw I think that the idea of a pacemaker sounds like a perfectly sound plan. If you already have a non-pathological bradycardia then adding AF to the mix might mean that occasionally you could experience very brief pauses in your conduction that can make you either light-headed or temporarily pass out (known as syncope); very rare, but a possibility.
A pacemaker would not necessarily be inserted to increase your heart rate (I am sure that you have been absolutely fine up until now with your naturally low heart rate) but it would be there to jump in and pick up the rate if it falls to a rate that is too low and to prevent those syncopal episodes; it is precautionary, particularly if they have you on beta blockers.
Ablation can be highly effective, but does not work in some cases, so I think that it could be a good fall back to have the pacemaker. These days, they are small, efficient and can be inserted very easily. Personally, I would have one in a heartbeat (pun intended).
I hope that all works out well for you and that you are flying again soon.
Best wishes
Andrew