I have only once had serious arrythmia. It was after an operation on my nose. When I came round after the operation, my heart was beating very hard and irregular, so much that I could hear it clearly. I was also totally unable to move or speak, and I was gasping uncontrollably. For a few minutes I was put on O2 and I felt a bit better, but then they took it away and things got worse again. The whole thing lasted an hour, then I was sent home.
For the rest of the day I didn't feel so bad, but at night the trouble came back with a vengeance. The main problem was that I couldn't breathe in normally because I hadn't got much control of my diaphragm (or at least that's what I think it was) so every time I wanted to breathe, I had to gulp air deliberately. This lasted for 12 hours. If only I'd known about packing.
The pain in my nose was also driving me mad, as was the fact that it was completely blocked and bleeding constantly. It was easily the worst thing I've ever experienced. All the other bad things, such as having a broken arm, being trapped underwater, etc seem like nothing next to this monumental ordeal.
Afterwards I was left with many problems, such as shaky hands, weak voice and uncontrolled breathing. Most of these are gone by now. The only things that are left are a slight shaky loss of coordination which is brought on by physical effort or stress, and a slight weakness which means that I can't take a full breath if I am standing up to my neck in water, so I have to pack to get to normal volume. I'm OK though...
Lucia