As has been said, my layman opinion (now that's worth a lot - NOT!) is that it could be a number of things which could include a transient hypoglycemia or hyperglycemic event. E.g. if you'd been drinking alcohol the night before and hadn't yet eaten but you say it occurred on Wednesday and you only drink at the weekend.
Who knows? Sounds like monitor and see doc if it happens again.
I'd an inverted P wave on my ECG. That triggered off a whole series of tests which found yet another possible defect. In the end it was decided that there was nothing wrong and never had been
