A good buddy had to get ablations, it worked out with the FAA but IIRC he had to do it twice.
That was a wake-up call for me... his condition was due to too much sustained hard cardio exercise while not being young. I got a heart rate monitor and lo and behold my moderately hard routine runs had me pegged above the max heart rate for my age... not good.
I apparently slow-boiled myself by doing the same running I had been doing for decades, without regard for aging. Didn't really notice that it was getting harder on my body but my heart did. Backed off and now reference the fitbit to keep heart rate in the recommended range. Actually feel better with the slower runs.
Turns out you can still do max effort interval work without over-developing the heart, just keep it to short intervals.
So too much isn't good either, all things in moderation.