P wave changes suggestive of P mitrale often occur in patients with left ventricular hypertrophy. Indeed, these P wave changes may sometimes be the only ECG manifestation of LVH. This ECG is from a patient with hypertension and left ventricular hypertrophy. Note the prolonged, notched P wave in leads II, V5 and V6 and the negative component of the P wave in leads V1 and V2. The P wave abnormality reflects the diastolic dysfunction often present in patients with hypertensive heart disease. This causes an increase in left ventricular diastolic pressure which, in turn, results in an increase in left atrial pressure and left atrial hypertrophy.