I didn't want to make light of the situation, but "abnormalities" doesn't really tell us anything. Some abnormalities are seious, some won't affect his ability to play. All we know is the docs saw something they want to look at further.
I've had numerous EKG's, stress tests (one physical, one chemical), numerous echo-cardiogram tests, I've worn a 24-hour monitor twice, etc. So far I have atrial fibrillation, since my early 20's (controlled by medication). Three of my valves have minor leakage, also not a bar to physical activity. Latest echo shows mildly impaired left ventricular relaxation, apparently not too serious, at least at this time. One test showed a dark area that could have indicated part of my heart was dead tissue from a heart attack. Cardiologist said it was probably a just shadow, because my heart was pumping fine.
So, there can be a lot of "abnormalities" seen. All we can do is wait and see what further testing shows. I'll just say a little prayer that Hayes will be just fine.