Tried to go to bed after work. I work nights, and was on my phone, laying down. Problem is I fought the drowsiness a bit, and I think that might have triggered it. Heart went completely out of sync and started beating like I was on speed, but it wasn't the right kind of beat. I was at over 150 beats per minute, when the ambulance picked me up. And it was getting progressively worse. Since my heart was struggling to get back to normal, and the strain was giving me chest pain. They put me on a drug to slow down my heart-rate, and eventually I got back to the normal rhythm.
All of that only happened because I am one of the lucky ones who can actually notice it, because I am autistic regarding details like that, because if I didn't? It would have kept trying to fix itself until my heart stopped and just gave.