BACKGROUND: Programmed long AV delays and intrinsic long first degree AV block may increase risk for competitive atrial pacing (CAP) in devices without CAP avoidance algorithms. METHODS: Patients identified with CAP-induced mode switch episodes were followed clinically from 9/2013 to 08/2019. Attempts to avoid CAP included shortening of post-ventricular atrial refractory period (PVARP) or post ventricular atrial blanking period (PVAB), or change to AAI or DDI modes. After observing associations with sensor-driven pacing, rate-response was inactivated in a subset. RESULTS: Among 23 patients identified with CAP (22 St. Jude Medical [Abbott]; 1 Boston Scientific Corporation devices), atrial fibrillation (AF) was induced in 12 (52%), lasting 10 seconds to 28 hours and 32 minutes. In one patient with an ICD CAP induced AF with rapid ventricular rates that triggered a shock, inducing ventricular fibrillation, syncope and another shock. Changing AV delays and shortening of PVARP failed to resolve CAP. After noting that all had CAP during sensor-driven pacing, rate response was inactivated in 7, resolving further device-induced AF in the 3 of 7 that had prior CAP-induced AF. In 2 patients with intact AV conduction, AAI(R) pacing resolved further documentation of CAP. CONCLUSIONS: CAP predominantly occurs during sensor-driven atrial pacing that competes with intrinsic atrial events falling in PVARP. Inactivation of the activity sensor or change to atrial-based pacing modes (AAI/R) appears to effectively prevent induction of device-induced atrial proarrhythmia. Ultimately a corrective algorithm is needed to avoid CAP-induced proarrhythmia. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
BACKGROUND: Programmed long AV delays and intrinsic long first degree AV block may increase risk for competitive atrial pacing (CAP) in devices without CAP avoidance algorithms. METHODS:Patients identified with CAP-induced mode switch episodes were followed clinically from 9/2013 to 08/2019. Attempts to avoid CAP included shortening of post-ventricular atrial refractory period (PVARP) or post ventricular atrial blanking period (PVAB), or change to AAI or DDI modes. After observing associations with sensor-driven pacing, rate-response was inactivated in a subset. RESULTS: Among 23 patients identified with CAP (22 St. Jude Medical [Abbott]; 1 Boston Scientific Corporation devices), atrial fibrillation (AF) was induced in 12 (52%), lasting 10 seconds to 28 hours and 32 minutes. In one patient with an ICD CAP induced AF with rapid ventricular rates that triggered a shock, inducing ventricular fibrillation, syncope and another shock. Changing AV delays and shortening of PVARP failed to resolve CAP. After noting that all had CAP during sensor-driven pacing, rate response was inactivated in 7, resolving further device-induced AF in the 3 of 7 that had prior CAP-induced AF. In 2 patients with intact AV conduction, AAI(R) pacing resolved further documentation of CAP. CONCLUSIONS: CAP predominantly occurs during sensor-driven atrial pacing that competes with intrinsic atrial events falling in PVARP. Inactivation of the activity sensor or change to atrial-based pacing modes (AAI/R) appears to effectively prevent induction of device-induced atrial proarrhythmia. Ultimately a corrective algorithm is needed to avoid CAP-induced proarrhythmia. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Authors: Leonid Garber; Eric Shulman; Alexander Kushnir; Tajinderpal Saraon; David S Park; Larry A Chinitz Journal: HeartRhythm Case Rep Date: 2022-02-04