Electrocardiogram of an adolescent with hypertrophic cardiomyopathy

A 15-year-old patient with HCM and a documented disease-causing mutation in the gene MYBP3. The ECG was performed with limb leads at standard voltage calibration (10 mm = 1 mV) and precordial leads at half standard voltage calibration (5 mm = 1 mV). Note the markedly increased voltage consistent with LVH, T wave inversion in inferior and lateral leads, and prolonged QTc interval (measured at 480 msec), which due to marked LVH.