This means very little. This is an outlier person, who has drastically altered his bodily function. It is just silly to not know that exposing your body to the extreme conditions of deep diving, without oxygen, for extremely long periods of time, is terrible for your body. It’s just as obvious as the fact the running marathons is extremely harmful to the human body. Of course someone like this would get myocarditis. His entire cardiovascular system is already completely f**ked up from all of the oxygen deprivation and pressure from all the free diving!!!