Hi. I had an episode of a.f when I was on holiday in Wales I was on 5mg bisoprolol at the time. My heart rate was 217bpm. After 12 hours my heart went back to normal rhythm. And I haven’t had a problem until now. I’ve recently lost nearly 4 stone. And now my heart rate is going as low as 48bpm just before I sleep which scares the crap out of me as I feel I can’t breathe. I went to see the doctor yesterday as I’ve been getting bad panic attacks and anxiety because of this. My usual resting rate is in the 60’s during the day. She thinks the 10mg is too much and has dropped it to 7.5mg. Now I’m scared to take that incase I get another a.fib. I feel I can’t win. Has anybody else experienced this?