Real-world experience of mapping and pulsed field ablation with a novel multi-electrode variable loop device

Background and aims

Pulsed field ablation (PFA) has emerged as a novel energy modality for catheter ablation of atrial fibrillation (AF) aiming at pulmonary vein isolation (PVI). A novel catheter device with a multi-electrode variable loop (MEVLC device) allowing for cardiac mapping and ablation has recently become available. This study sought to investigate the feasibility of mapping and ablation utilizing the MEVL device in a real-world patient cohort.

Methods

Consecutive patients suffering from symptomatic paroxysmal or persistent AF undergoing first time catheter ablation aiming at PVI between April 2024 and November 2024 at our center were prospectively enrolled. Ablation aiming at PVI were carried out using the MEVLC device. Electroanatomic mapping was performed with the ablation device as well as with a dedicated high-density multipolar mapping catheter to assess feasibility of mapping using the MELVC device.

Results

A total of 33 patients (mean age 67.3±7.1 years, 23 patients (69.7%), 20 females, 23 with paroxysmal AF and 10 with persistent AF) were analyzed. Procedure duration was 68.7±14.1 minutes with fluoroscopy times of 3.5±1.6 minutes. Complete PVI at the end of procedure was achieved in 33 patients (100%) and 132/132 pulmonary veins (PVs). Remapping after the initial 16 ablation pulses demonstrated preserved electrical conduction in 8/132 PVs (6.1% of PVs) in 4 patients (12.1%). Repeat ablation to achieve complete PVI was performed and was successful in all cases with a mean of 3.5±1.7 additional ablations.

Comparison of parameters of mapping attempts with the mapping catheter and the ablation device are shown in Figures 1+2. Successful PV mapping was successful in 132/132 PVs with the mapping catheter and in 120/132 PVs with the MELVC device (P<0.001). In cases with failed PV engagement with the ablation device it was successfully placed at the PV antrum and PFA applications were delivered in two different loop sizes. Failure of PV engagement with the MELVC device did not result in insufficient PVI as demonstrated by remapping using the high-density mapping catheter. Sufficient correlation of post-ablation remapping of low voltage areas and ablation tags inside the electroanatomic mapping system was shown for all 33 cases. There were no periprocedural complications.

Conclusion

Catheter ablation aiming at PVI using a novel multi-electrode loop catheter for PFA was safe and effective. Integration of the ablation device into a 3D electroanatomic mapping system was feasible facilitating sufficient intracardiac mapping during the ablation procedures.

Figure 1

Overlay of electroanatomical maps with a high-density multielectrode catheter (glass mode) and the ablation device (color-coded map) (A). All PVs were successful engaged with the MEVLC device for mapping. Localization of ablation spots is visualized by grid tags (B). Post-ablation remapping with a multielectrode catheter demonstrates good correlation between low-voltage areas and ablation tags (C).