I don't know whether anyone can help with this or offer some insight... I've been a keen runner for about 12 years and consider myself to be reasonably fit, though overweight. 3 years ago at the age of 42, I had a minor NSTEMI heart attack - the angiogram showed a partial blockage of just one artery so it was treated medically with no stents. I've not had any angina or problems since then.
When I was discharged I was given the same advise as is given everyone I suspect, with or without stents, which is to keep effort levels of exercise to a level where you could hold a conversation. With the beta blockers, this usually correlated to a heart rate of about 130bpm for me. As time has gone on though, given that I've not had problems, I started to push myself again with the running and a good effort run (once a week, often a parkrun) took my heart rate to about 145 bpm. Recently though, my watch has started telling me that my pulse is not dipping below 150 during an decent run and can go up to 180. My resting heart rate seems unchanged. Given that my heart attack was relatively minor, do you think I should be worried about this? Will it increase my risk of further problems? I don't have much confidence that my regular GP will know the answers, so they will just give the standard advice again I'm sure. Any thoughts?