Concurrent Micra Leadless Pacemaker Implantation and AVN Ablation: Computer Modeling of Novel Risk Mitigation Strategy.

Background: Concurrent Micra leadless pacemaker (Medtronic, Minneapolis, Minnesota) implantation and atrioventricular node (AVN) ablation has been shown to be feasible and safe in patients with symptomatic, drug-refractory atrial fibrillation (AF). However, major complications within the 30 days after concurrent Micra implantation and AVN ablation have been reported. We evaluated the efficacy and safety of the concurrent procedure at our institution.

Methods: We conducted a single-center, retrospective case series of patients who underwent concurrent Micra implantation and radiofrequency (RF) AVN ablation from January 2019 to May 2023. A simulated computer model was created to characterize the interaction between the dissipated power at the Micra cathodal electrode as a function of the distance between the RF ablation catheter and the location of the return electrode.

Results: Fifteen patients were included. Most were elderly, White, female, and had persistent AF. One had transient, acute loss of ventricular capture that resulted in asystole and required emergent pacing from the ablation catheter. A proposed strategy of moving the RF return electrode to a cranial position from a caudal position was shown by computer modeling to direct more RF current away from the Micra and lower the dissipated power at the Micra cathodal electrode.

Conclusion: Concurrent Micra implantation and AVN ablation is feasible and safe and has high procedural success. An acute rise in pacing threshold can occur from RF energy, resulting in asystole. Computer modeling showed that placing the RF return electrode in the cranial position resulted in lower dissipated power at the Micra cathodal electrode.