I was commenting to a different thread here in the forum and it got me thinking.
There is some fairly reliable statistics on heart attack mortality among marathon runners. It's around 1 per 100,000 marathons, counting deaths during the marathon and the first 24 hours after the finish.
As far as the heart is concerned, marathon running isn't all that different from vigorous cycling, except that runners spend less time at high HR than cyclists, during training and during events. If I assume that marathon mortality scales as total time spent in high HR zones, then a cyclist who spends 5 hours/week (one long weekend ride) at comparable intensity would have 1 in 1600 odds of dying of a heart attack in any given year. Which is huge (on par with traffic accident mortality rates among active motorcyclists, or with homicide mortality rates in most violent cities in the United States.)
Then I tried to find statistics on heart attacks in cyclists, and I drew a blank there. All I could find were anecdotal stories of two young pro cyclists dying of heart attacks in 2004 (alluded to be linked to doping), and references to Ed Burke.
Am I wrong in assuming that heart attack mortality scales with time? Or are there predisposing factors that determine whether you're at high risk of having a heart attack eventually? If I get a EKG it says that I don't have hypertrophic cardiomyopathy now, does that say anything about my odds?