Why do perfectly healthy athletes have cardiac arrest due to over-exhaustion, evolutionarily speaking?

If we look at people losing consciousness due to a lack of oxygen, that makes sense, because its about conserving the energy, and then when oxygen becomes available the brain can return to consciousness (unless there's been damage).

So there's two things:

1. In the case of a person with a perfectly healthy heart, it seems counter-intuitive that evolution would prefer to have the solution be the person dies instead of making the person lose consciousness for a period of time to recover from the over-exhaustion (and yes I know this also happens, but here I'm focusing on the other outcome).
2. When some top-level athlete has a cardiac arrest due to over-exhaustion on the playing field, why didn't the body evolve to reset the heart in the same way that a shocking device does? I know that sometimes shocking devices don't work for people who have heart problems, but here we're talking about people who don't have heart problems, but have had a cardiac arrest due to over-exhaustion.

Or am I tricking myself here by making the wrong assumption that it can actually happen to a perfectly healthy heart, and all the cases where it did happen to health-screened top-level athletes there were some kind of drugs involved?

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