No, I am not 100% certain it's not heart disease and neither would a doctor be certain without putting the kid through thousands of dollars worth of tests, which at that age, more than likely would be foregone. I believe I said it would be prudent to ask the kid if he's talked to his doctor about this. If that's not enough to appease some of the medical anxieties, sorry, it's the best I'll do. This board is for trumpet talk, and just because some of us would rather focus on the trumpet playing aspect of this discussion, doesn't mean we don't care about the kids health. The trumpet is a physical instrument and playing it wrong CAN cause stress and pain. That was the focus of my response to this thread precisely because I am NOT a doctor.