I appreciate that most people here don't follow soccer, but I thought I'd post this in light of the popular notion that only big, strong weightlifters have this sort of thing occur among athletes.
"The player's life was saved thanks to the rapid intervention of the club doctors and the Red Cross because he had a number of cardiac arrests," del Nido was quoted as saying on the club's website after visiting Puerta on Sunday.
There has been a case of several soccer players actually dying (or nearly so) in similar incidents, and their body mass is usually average with low body fat.
Although I'm not a medical professional, I would make the case that this actually does happen to many different athletes and if athletes with very draining and unhealthy lifestyles (stress, collisions, recreational drugs, alcohol) were taken out of the equation, this myth that having a certain amount of muscle mass will bring about death would be dispelled.
Oh, and wishing Antonio a speedy recovery.