Alignment of estimated electric field tags with low-voltage borders using a new EAM-integrated pentaspline pulsed field ablation system

Background

A novel pentaspline pulsed field ablation (PFA) catheter integrated with an electroanatomical mapping (EAM) system combines magnetic sensor localization, real-time visualization of catheter deployment shape, and preview of estimated electric field tags. However, data assessing the spatial accuracy of this technology compared with high-density mapping systems in clinical practice are limited.

Purpose

To evaluate the concordance between the estimated shape and position of the pentaspline PFA field tags and the low-voltage border identified by a 64-pole high-density mapping catheter following pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF).

Methods

Protocol-guided PVI was performed using a magnetically tracked, EAM-integrated pentaspline PFA catheter. Energy was delivered at 2 kV with eight applications per vein, with additional applications at the operator’s discretion to ensure isolation. Estimated electric field tags were automatically generated with each application by Faraview software. After PVI, a high-density three-dimensional left atrial voltage map was acquired using a 64-pole Orion basket catheter and the Opal mapping system (Boston Scientific). Bipolar voltage <0.5 mV was defined as low voltage, representing acute lesion formation or chronic scarring.

Results

A total of 420 field tags from 10 procedures were analyzed. The mean ablated area measured by the Orion catheter was 63.7 ± 10 cm² (28.2 ± 6 cm² for the left pulmonary veins [LPVs], 35.6 ± 5 cm² for the right pulmonary veins [RPVs]). High-density mapping confirmed complete electrical isolation of all PVs. The ablation footprint, as visualized by the integrated Faraview software, measured 65.2 ± 8 cm² and correlated closely with the post-ablation low-voltage area (p = 0.557), with a mean absolute difference of 1.5 ± 6 cm² (median 1.3 [–4.4 to 6.2] cm²) and a mean percentage difference of 2.1 ± 9% (median 2.1 [–7 to 8]%).

The ablation footprint marking line delineated the border zone (0.2–0.5 mV) with a mean area of 4.4 ± 0.7 cm² (7 ± 1%). The average distance between field tags and the low-voltage border was 1.1 ± 4 mm (median 1.5 [–1.2 to 4.2] mm), measuring 0.7 ± 4 mm in RPVs and 1.6 ± 4 mm in LPVs, and ranging from –0.3 ± 3 mm in inferior to 2 ± 5 mm in superior PV segments. Figure 1 and 2.

Conclusion

The region of acute electrical isolation demonstrated close alignment with the estimated electric field generated by the novel EAM-integrated PFA catheter. The ablation footprint marking line accurately delineated the lesion boundary, suggesting that this visualization tool may provide reliable procedural guidance for real-time lesion assessment in clinical practice.