This electrocardiogram shows right ventricular hypertrophy + right axis deviation + left atrial enlargement.

The characteristic features of right ventricular hypertrophy demonstrated here include a taller than normal R wave in lead V1 with an R/S ratio of one or more. Right axis deviation, which is also typical of right ventricular hypertrophy, is reflected by the predominantly negative QRS deflection in lead I. Left atrial enlargement is reflected by the increased width of the P wave in lead II and the prominent negative component of the P wave in lead V1. These electrocardiographic changes are typical of mitral stenosis.