A 15-year-old boy collapses during a basketball game. What is the most likely etiology of sudden death in this adolescent?

A 15-year-old boy collapses during a basketball game. What is the most likely etiology of sudden death in this adolescent?

• A. Mitral valve prolapse
• B. Surgically corrected aortic stenosis
• C. Hypertrophic cardiomyopathy
• D. Rheumatic heart disease

Answer: (C)

The situation points to a heart muscle disease that predisposes to dangerous rhythms during strenuous activity. Hypertrophic cardiomyopathy causes abnormal thickening of the heart muscle, especially the interventricular septum, with disorganized heart muscle fibers and often some fibrosis. This combination can create a dynamic obstruction of the left ventricular outflow tract and, more importantly, makes the heart prone to malignant ventricular arrhythmias during exercise when sympathetic tone and demand are high. Those arrhythmias can lead to sudden cardiac arrest in a young athlete, which is why this condition is the most common cause of sudden death in adolescents during sports. Other options are less likely in this context. Mitral valve prolapse can cause arrhythmias but is a less frequent cause of sudden death in teens during athletic activity. A surgically corrected aortic stenosis reduces risk, but residual or intrinsic myocardial factors may still pose danger, and it is not the classic cause of sudden death in this age group. Rheumatic heart disease usually leads to chronic valve problems rather than abrupt collapse during exertion in a previously healthy adolescent.

The situation points to a heart muscle disease that predisposes to dangerous rhythms during strenuous activity. Hypertrophic cardiomyopathy causes abnormal thickening of the heart muscle, especially the interventricular septum, with disorganized heart muscle fibers and often some fibrosis. This combination can create a dynamic obstruction of the left ventricular outflow tract and, more importantly, makes the heart prone to malignant ventricular arrhythmias during exercise when sympathetic tone and demand are high. Those arrhythmias can lead to sudden cardiac arrest in a young athlete, which is why this condition is the most common cause of sudden death in adolescents during sports.

Other options are less likely in this context. Mitral valve prolapse can cause arrhythmias but is a less frequent cause of sudden death in teens during athletic activity. A surgically corrected aortic stenosis reduces risk, but residual or intrinsic myocardial factors may still pose danger, and it is not the classic cause of sudden death in this age group. Rheumatic heart disease usually leads to chronic valve problems rather than abrupt collapse during exertion in a previously healthy adolescent.