Intra-His bundle block in second-degree Mobitz I atrioventricular block with right bundle branch block.

Because second-degree Mobitz I atrioventricular (AV) block is usually associated with a disturbance at the AV nodal level, and rarely at the infra- or intra-His bundle level, it has been considered as mostly benign in character. We report on a patient with intra-His bundle block in second-degree Mobitz I AV block with right bundle branch block.