The risk of sudden unexpected death in otherwise healthy-appearing people has always presented a perplexing paradox for both patients and physicians. 鈥淚 just talked to him 1 hour ago, and he seemed perfectly normal.鈥� 鈥淗ow could this happen?鈥� or 鈥淪he always took great care of herself, exercised regularly and ate healthy. How could this happen?鈥� All physicians in the general practicing community have heard this, and the answers seem to lie largely with the inherent unpredictability of cardiac diseases and our imperfect ability to anticipate and prevent such events.¹ When such a death occurs in a child or young adult, it seems even more counterintuitive and tragic.