I am truly very sorry to hear this news.
As some of you know, my own son lost his best friend last February to SADS. Sudden Arrhythmia Death Syndrome. He simply went to sleep in his dorm room and never woke up. He had annual physicals each year, was an athlete, and never displayed any symptoms. SADS is totally treatable, but it must be diagnosed. Some simple tests can be performed, to identify it, but you must ask for them. Please go the the website provided and educate yourself and pass the word.
SADSThanks,
Iheartbb