Male 60 yrs old. Diagnosed with SVT in 2009 and recently been given diagnosis of paroxysmal atrial fibullation and put on Bisoprolol 2.5mg tablets daily. This Monday was like any other - started at the gym for 3km row and 2km bike - both at gentle rather than straining pace. Heart rate pretty normal - 70s rising to 120 on the exercise bike and back down quickly. Spent day cutting, splitting and stacking wood. Felt exhausted by 3 and whilst sitting at laptop at 4 going over music for choir that night could feel HR rising - it wasn't that high and I didn't bother with my monitor strap. Went to choir and whilst rehearsing could feel HR rise again - quite severely - and then went into episode where I thought I was going to faint (this is not that unusual for me, and I never have actually fainted).
This developed into an episode the like of which was completely new - I realised I couldn't move - I was shaking and bent over (I had been standing). People nearby were quite concerned. After about 10-15 seconds that passed and I sat down, gathered myself and went outside to the fresh air. I didn't have my HR monitor strap on so don't know the HR but it has been at 220+ on occasions and this might well have been a new record. It was deeply unpleasant and has left me rather shaken. Because I was due to drive other people home after the rehearsal, I made arrangements for someone else to do this and for my wife to come to drive me home.
Since then, my HR has been high-ish (it has certainly NOT gone back to its normal behaviour) fluctuating between 80 - 140 and also going down (if HR monitor is to be believed) to 40s-50s. This has been going on for 48 hours now. Previous periods were never longer than 24 and nearly always 4-5 hours or less.
I saw a doctor the next morning and she suggested upping the dosage if that episode repeats but I am wondering if I should do something else now that 48 hours have elapsed and the HR is still not settled down.
I am new to this forum - apologies if this is not the right place for this post - I have looked around but haven't found a collection of "this is my experience" stories.