Proarrhythmic effects of dynamic atrioventricular delay programming in a patient with cardiac resynchronization therapy and activity-induced atrioventricular node dysfunction

Key Teaching Points•Pacing algorithms that automatically adjust the intervals between paced beats may be proarrhythmic.•Exercise-mediated atrioventricular block or exercise-mediated prolongation of the PR interval needs to be considered prior to use of the SyncAV cardiac resynchronization therapy (CRT) algorithm.•If ventricular tachycardia is induced by the SyncAV CRT algorithm, there are multiple possible programming strategies that can be considered to prevent recurrence. •Pacing algorithms that automatically adjust the intervals between paced beats may be proarrhythmic.•Exercise-mediated atrioventricular block or exercise-mediated prolongation of the PR interval needs to be considered prior to use of the SyncAV cardiac resynchronization therapy (CRT) algorithm.•If ventricular tachycardia is induced by the SyncAV CRT algorithm, there are multiple possible programming strategies that can be considered to prevent recurrence.