I had an isolated instance of rapid atrial fibrillation while playing college volleyball (almost the same age as Marcus). It was incredibly scary. Fortunately, at the hospital, they were able to kick it back to normal with meds. After running a bunch of tests (echocardiogram, stress echo, multiple ekgs, bloodwork) they couldn't find reason why it happened. I'm now 32, haven't changed any aspects of my life, and it hasn't happened again since. Hopefully it'll be the same for Marcus. Having gone on this long I'd probably guess the docs will want to use electric cardioversion to prevent clots from forming. After having the problem I did quite a bit of reading. It sounds like it is typically very fixable and he'll live a healthy life. Whether he can play professional sports will be the question...any MDs with better knowledge?