http://www.arvd.com/q_a.html'>http://www.arvd.com/q_a.html
i am not on the site every day so i apologize if this has been covered...but i coach college distance runners and after 15 years with zero incidence of heart problems, i've had 2 athletes sent to the cardiologist this year.
one situation is treatable and the athlete will be back after either meds (hopefully they work, and often they do) or a relatively simple surgical procedure (as "simple" as heart surgery could be!):
http://en.wikipedia.org/wiki/Supraventricular_tachycardia
the other is a chronic, degenerative and potentially fatal condition that is typically the cause of death in healthy people who mysteriously die of heart failure while running, playing soccer, etc. You hear about these incidents fairly often, but ususally the cause is not disclosed:
http://www.arvd.com/q_a.html
the second of my two athletes has arvd and she is done running forever...it is a sad case, she was a state-caliber miler in her junior year of h.s. and started a slow downward spiral from there. her performance got worse and worse, her endurance went to hell...couldn't finish races and usually preformed at a very sub-par level when she did. after 2 years of struggle went to Johns Hopkins and diagnosed with the ARVD and told never to exercise- or risk sudden heart failure. scary stuff for an athletic 19 year old to deal with. she'll eventually have a pacemaker transplanted and hope that she'll stabilize to the point where she can safely tolerate moderate exercise.
anyway, when i heard Easley was put on IR, i immediately feared this was the problem. by contrast, if it was SVT, there would be no reason to put him on IR yet, because there's be a good chance he could safely return after treatment.
so anyway, that is my speculation on what may have happened. i hope i am wrong, because it's a sad and scary thing a young athlete to hear.