Cardiovascular Implantable Electronic Devices -> Monitoring & Outcomes: -> Quality Measures & Complications D-PO05 - Poster Session V (ID 39) Poster

D-PO05-103 - Proarrhythmic Effects From Competitive Atrial Pacing And Potential Programming Solutions (ID 551)


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.
Objective: To report a series of cases with CAP, potential serious clinical consequences of CAP, and identify potential programming solutions.
Methods: Patients identified with CAP-induced mode switch episodes were followed clinically. 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 10 (43%), lasting 6 seconds to 15 hours 45 minutes. 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.
Conclusion: 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.