Right bundle branch block and right ventricular hypertrophy

ECG: Atrial sinus activity, normal PR interval (190 ms), complete right bundle branch block pattern (QRS duration 180 ms, rsR’ pattern in V1) with right ventricular hypertrophy (high amplitude R’ wave in V1, very deep and wide S wave in leads I, V5, V6, markedly delayed intrinsicoid deflection in V1, repolarization disorders from V1 to V3);

Comments: The electrical diagnosis of right ventricular hypertrophy is difficult in the presence of a right bundle branch block and is expressed only if the hypertrophy is anatomically significant.

In the presence of a complete right bundle branch block, the following signs are typical for hypertrophy:

• A high amplitude R’ wave exceeding 15 mm in V1
• A very wide S wave in lead I
• A significant delay in intrinsicoid deflection in the right precordial leads

These various parameters are observed in this patient, with right ventricular hypertrophy frequently occurring in patients with chronic cor pulmonale.

Take-home message: A major right axis deviation in a patient with a right bundle branch block can reflect the presence of right ventricular hypertrophy or an associated left posterior fascicular block. The presence of a high-amplitude R’ wave is particularly suggestive of a right ventricular hypertrophy.