New onset of electrocardiographic abnormalities heralding hypertrophic cardiomyopathy in an adult athlete

A 41-year-old male asymptomatic athlete with unremarkable personal and family history of heart disease underwent annual preparticipation screening. No abnormalities were noted on prior testing. On this occasion, a 12-lead electrocardiogram showed diffused and marked repolarization abnormalities. He was therefore referred for echocardiography, which showed moderate asymmetric hypertrophy localized at the mid-apical portions of the left ventricular anterolateral wall. Cardiac magnetic resonance confirmed the diagnosis of hypertrophic cardiomyopathy. Re-evaluation of the electrocardiogram performed the previous year revealed a completely normal tracing.