Which condition is most likely in a young athlete who collapses suddenly during sports?

Hypertrophic cardiomyopathy is often the most likely condition in a young athlete who collapses suddenly during sports. This genetic heart disease is characterized by an abnormal thickening of the heart muscle, particularly affecting the left ventricle. This hypertrophy can lead to outflow obstruction and impaired diastolic function, which significantly increases the risk of life-threatening arrhythmias and sudden cardiac death, particularly during periods of intense physical exertion.

Young athletes may be asymptomatic or present with mild symptoms, which can delay diagnosis. Upon exertion, the thickened heart muscle can cause arrhythmias that result in syncope or collapse. The association of hypertrophic cardiomyopathy with sports is particularly concerning, and it is one of the most common causes of sudden cardiac death in athletes.

Other conditions listed, while potentially serious, may not present with the same epidemiological frequency in the context of young athletes abruptly collapsing during physical activity.