As a Kent State University football player, Jason Bitsko was seemingly healthy—until he died after practice on Aug. 20. The coroner determined that the cause of death was HCM, or hypertrophic cardiomyopathy, a condition whose first symptom often is death.

HCM, the most common cause of sudden cardiac death in young American athletes, is usually detectable via a routine EKG, or electrocardiogram. And while most colleges, including Kent State, don’t subject athletes to EKGs, growing numbers of them do, including Louisiana State,...