Electrocardiographic Pattern of Right Bundle Branch Block

Diagnostic Criteria for Complete Right Bundle Branch Block

The American College of Cardiology defines complete right bundle branch block as a QRS duration ≥120 ms in adults, with a specific pattern in leads V1 or V2, where the R' or r' deflection is generally wider than the initial R wave, accompanied by S waves of longer duration than the R wave or >40 ms in leads I and V6, and a normal R peak time in V5 and V6 but >50 ms in V1 1, 2, 3
The American College of Cardiology recommends a QRS duration ≥120 ms as a diagnostic criterion for complete right bundle branch block in adults 1, 4
A pattern of rsr', rsR', rSR, or rarely qR in leads V1 or V2, where the R' or r' deflection is generally wider than the initial R wave, is a diagnostic criterion for complete right bundle branch block 1, 2
The presence of a wide and frequently notched R wave in V1 and/or V2 is a characteristic finding in some patients with complete right bundle branch block 1, 4
The American College of Cardiology states that an S wave of longer duration than the R wave or >40 ms in leads I and V6 is a diagnostic criterion for complete right bundle branch block 1, 3
A normal R peak time in V5 and V6 but >50 ms in V1 is a diagnostic criterion for complete right bundle branch block 1, 2

The American College of Cardiology defines incomplete right bundle branch block as a QRS duration between 110 and 119 ms, with the same morphological criteria as complete right bundle branch block 1, 4
In children, incomplete right bundle branch block can be diagnosed when the terminal deflection to the right is <40 ms but ≥20 ms 4