I dont know about a week but apparently in the lead up to a heart attack you experience a feeling of dread, among other things.
Probably a case of just knowing your body and knowing something was wrong
Youre right it might not have been the first time this happened to him I didnt think about that until now.
My condolences for your loss
https://en.m.wikipedia.org/wiki/Abraham_de_Moivre
This dude allegedly noticed he was sleeping 15 minutes longer than normal, and predicted that once he slept for a full 24 hours that would be the day he died. Though whatever or not that truly happened is up for debate.
Though sometimes people do make eerily accurate predictions. My grandmother was good for them. Like once she told her husband to get out from behind thus car something was about to happen. He did and suddenly that cars hood flew up causing him to swerve off the road.
More mild but not long ago I saw a bird flying towards my car as I'm driving and my mind said it's gonna shit on my car. And yep dead center of the windshield