Glad I found this thread.. Over 20 yrs ago, I would smoke all the time, many times a day. This went on for many years. Worst thing would be a little paranoia but never felt rapid heart rate. Took a long of time off smoking, just under 20 yrs, and started smoking again a couple years ago. Only recently have I felt heart racing and palpitations. I have high BP, getting old sucks. I have a BP cuff and both HR and BP went up very high after lighting up. Mentally, was not paranoid or having anxiety. Only fear that kicked in after realizing what was going on. so I reluctantly stopped smoking. Wondering if I can train myself back or not. So far haven't tried cause it's not worth the risk.
while I was going through this, a little while ago, a friend of mine died of a heart attack - lived in a different state, we weren't smoking the same weed. It was completely out of the blue. We are in our early 40's. He wasn't a drinker and his only drug was weed. Overall in good health and his parents are still around so no family concerns of heart attacks. I can't say if the weed caused it but I know he didn't have high BP or know of any medical issues. And he was smoking that night. No other drugs.
Try googling 'heart attack marijuana'. You can't trust everything online but there seems to be enough out there to support the possibility.
My dilemma is I'm trying to kick something else and wanted to use weed to help. But I guess that's off the table.