An Unusual Cause of AV Dyssynchrony

Abstract

A 71-year-old male with persistent atrial fibrillation and a dual chamber permanent pacemaker presented complaining of dyspnea on exertion, easy fatiguability, and intermittent cough. A 12-lead electrocardiogram revealed ventricular paced complexes, native QRS complexes, and irregular atrial activity. Herein we present an unusual mechanism of atrioventricular dyssynchrony. (Level of Difficulty: Intermediate.)

Keywords

• atrioventricular dyssynchrony
• decremental conduction
• dual atrioventricular node physiology
• fast pathway
• retrograde conduction
• slow pathway