Mitral stenosis electrocardiogram


 * Associate Editor-In-Chief: ; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.

Electrocardiographic findings in Mitral stenosis
1. LA enlargement: Left atrial enlargement produces a broad, bifid P wave in lead II (P mitrale) and enlarges the terminal negative portion of the P wave in VI.

In lead II following may be seen:
 * Bifid P wave with > 40 ms between the two peaks
 * Total P wave duration > 110 ms

In lead V1 follwing may be seen:
 * Biphasic P wave with terminal negative portion > 40 ms duration
 * Biphasic P wave with terminal negative portion > 1mm deep



2. Right ventricular hypertrophy: A mean QRS axis in the frontal plane is greater than 80 and an R-to-S ratio of greater than 1 in lead V1.

3. Right axis deviation: mean QRS axis in the frontal plane moves toward the right as pulmonary hypertension worsens.

4. Atrial fibrillation is commonly seen with mitral stenosis: Irregularly irregular rhythm with absence P waves.

Below is an ECG in mitral stenosis