

Heartbeat stopping in the night. Luckily, the heart has mechanisms to restart itself, and the last one finally kicked in. According to the doc, this only took five to ten seconds, but it felt longer than the complete last class on a Friday afternoon.
Somewhere in my mid-twenties. I probably woke up before when my circulation went down. This had happened a few times before, with one occasion where I measured 26BPM with the blood pressure meter.
Luckily, they found that the medication I had to take back then was the issue, and switched me to another one, which I take for 30+ years now without issues.