Glad to hear you are doing better. A lot of seniors die from pneumonia. What I know about A-Fib is that it's very dangerous and does cause strokes which can lead to death. I remember when Arnold Palmer had it pretty bad and now I understand that Abdul-Jabbar has it as does approximately 5% of the population in the U.S.
I was in the hospital for 10 days back in January for back surgery. They put all kinds of junk into my lower lumbar spine and sent me home with a half paralyzed left leg and pneumonia, which also gave me thrush from my inhaler. There are times when you can follow the doctors' orders and still end up with added issues.