This electrocardiogram shows left ventricular hypertrophy and left atrial enlargement. The characteristic features of left ventricular hypertrophy demonstrated here include: increased voltage, reflected by the S wave in V1 plus the R wave in V5 exceeding 35 mm. Associated tall R waves in leads I and V4 and V6; and ST-T abnormalities in the same leads. Left atrial enlargement is reflected by the notched P wave in lead II and the large negative component of the P wave in lead V1.

Evidence for left ventricular hypertrophy on the electrocardiogram occurs relatively late in the course patients with hypertension. It is an independent predictor of increased morbidity and mortality.