Hopes, it sounds like you have answered your own question, lol. I also know a night like that would not be funny :(
It seems totally possible that your heart could have gone into any type of arrhythmia that could cause your heart to stop pumping correctly. That might explain the dizziness, and maybe nausea resulting from the run of whatever, due to lack of circulation and pressure.
Then again, could it have been a coronary artery spasm? Theoretically
you could have come close to a myocardial infarction (MI), and that could have caused your nausea and dizziness. Did you have any chest pain when you woke?
These are just about the worse case scenarios that my mind can conjure up, right now. I just always expect the best, from any of my symptoms including abnormal rhythms, but am prepared for the worse.
I think you may have mentioned taking CCB's (calcium channel blockers) for the spasms, but I have forgot.....Anyways, I would see my cardiologist about these events. As Delta says "listen to your body talk". I have my ear to the ground, on my body.... :)
Well, I have talked about enough scary stuff for ya in one post. I guess I am trying to impersonate Erskine today, ha ha ha.
Hopes ya have no more nights like last night :)