Was it a heart attack or cardiac arrest? There is a difference. Heart attacks involve muscle damage and cardiac arrests involve the electrical activity in the heart that causes it to suddenly stop. There usually is no associated heart muscle damage involved. I would find out for sure.
You weren't very specific as to what kind of problem you thought you might have. That is a very low heart rate and the BP is pretty low. I feel sleepy when my systolic drops into the 90's. The fact that you do marathons means you're athletic and many athletes have lower heart rates. The heart attack is something all together different. Did your doc explain what caused it or how much damage was done and where?
Very possible, I'd say.
I also think that my runny nose has caused me a problem, as does my sore foot.