Potential pacemaker implantation in an intra-atrial conduction block mimicking a complete atrioventricular block

Intra-atrial conduction dissociations resulting from incisions made during mitral valve surgery or maze procedures reportedly cause pseudo-atrioventricular blocks, in which atrioventricular node function is preserved despite the electrocardiogram indicating an atrioventricular block. We evaluated a 55-year-old man with a pseudo-atrioventricular block for potential pacemaker implantation. The stroke volume was higher without pacing than with simulated pacing mimicking an implanted pacemaker. Additionally, escape beat responsiveness was maintained during an exercise stress test. Based on these results and the absence of symptoms, we decided not to implant a pacemaker in the patient.