[maj0rhn]

Almost. I think you're confusing "heart failure" with "myocardial infarction." They are two different diseases. Collapse during exertion can happen in either one, but in Seth's case myocardial infarction is more likely, because people with heart failure generally don't go hiking (their exercise tolerance is too limited).

[GigabyteCoin]

I may very well have confused the two as I am not an expert in the topic. Thank you for the clarification.