Blood Pressure as indicator of oncoming problem?

Hi everyone.
Every once in a while, I'll get a rush of dizziness or light-headedness, accompanied by mild nausea and general disorientation. I used to contribute this to a-fib, or the medication I'm taking (beta blocker Bystolic). I'm wondering if that is accurate, though.
My question is this....if it were something else coming on, like (and I know this isn't highly likely right now for me) a heart attack or something like that, would there be a noticeable change in blood pressure at that time? I ask because my bp and heart rate seem pretty normal when these "spells" occur, but I don't want to just write them off if it's possible that something else might be happening besides medication side effects.

pulse rate usually stays in the 60's and 70's.....after a shot of light-headedness, it can get up to high 80's, low 90's. if it's meds, i'm ok with that. just really want to rule out anything else.
it's strange when it happens....like a wave of dizziness, can still breath just fine but can't seem to focus on anything for a minute or so. it feels like i get really exhausted after it happens, too.