Electrocardiographic and electrophysiological characteristics of ventricular arrhythmias from right bundle branch of the moderator band.

QRS morphology of MB-RBB VAs is characterized by a typical left bundle branch block pattern with a relatively narrow QRS complex, short r wave and rS durations, and a sharp S wave downstroke without notching in leads V1 and V2. Mapping and ablation of the leading RBB potential are effective for eliminating VAs.