In the United States, a young competitive athlete dies suddenly every three days. Young athletes are more than twice as likely to experience Sudden Cardiac Death (SCD) than young non-athletes. Most victims are male (90%), more than half of HCM sudden death victims are black athletes (52%), and the average age when SCD occurs in young athletes is 17.5 years. The risk of SCD increases with age. More than two thirds of young athletes who die suddenly are basketball and football players (67%).

Congenital Coronary Artery Anomalies (CCAAs) reportedly cause SCD in 12% to 33% of athletes.
Cardiomyopathy, most commonly Hypertrophic Cardiomyopathy (HCM), has been consistently demonstrated as the most common cause of exercise-related SCD in young athletes.

HCM is a thickening of the heart muscle walls. The thickened muscle can disrupt the heart’s electrical
system, leading to fast or irregular heartbeats (arrhythmias), which can lead to SCD. HCM is the leading cardiovascular cause of SCD (36%) in young athletes, it often goes undetected, and it affects black
athletes disproportionately (20% death rate for black athletes, 10% for white athletes). Deaths caused
by HCM are common in start-stop sports, such as football and basketball, but rare in endurance sports
such as rowing, long-distance cycling, and running. The diagnosis is made using electrocardiography
(ECG/EKG) and echocardiography.