I'll take a crack at this one. When something like an enlarged ticker shows up on an X-ray or on an EKG, especially in larger people, it gets overlooked unless the patient is symptomatic. Especially if he's an athlete.
"Well, looks like he has an enlarged heart, but he IS a big 'ol boy, and hell he's statistically outside of the age range to have any issues right now anyway..."
Could this have been prevented? To a degree maybe, but take into account where this particular guy came from, what his family history was, what his occupation was, as well as his obligations to his family.
He grew up in the Dallas area, more than likely eating lots of southern cooking, had bad cardiac genetics to begin with, and was encouraged to "keep on eatin" in order for to him to maintain a roster spot. Now, to come from a College system like Utah, and to only be on the practice squad as well as spend the spring/early summer in Europe one can safely assume that Herion was either slow in speed, slow in picking up the intricacies of being a quality NFL lineman, or just not mean enough. Lord knows it wasn't because he was just too small. So, with that being said, you have to figure that he took especially big risks and put lots of uneccesary strain on his body to achieve his goals.
Can anyone here say that they haven't done that? Put your body through a risky scenario that might have had unsavoury consequences to achieve a goal?
In Mr. Herion's case he was unlucky, the cards werent' in his favor, the stress that he put on his body to achieve his goals ended up killing him.
This story helps me realize that life is really fucking fragile, no matter who you are or what you do...