Effects of In Vivo Contact Force on Pulsed-Field Ablation Efficacy in Porcine Ventricles

Background

Pulsed-field ablation (PFA) is an innovative non-thermal method for arrhythmia treatment. The efficacy of various PFA configurations in relation to contact force (CF) has not been well-studied in vivo.

Objectives

This study evaluated the effect of CF on acute bipolar PFA lesions in both a vegetal and an in vivo porcine heart model.

Methods

Bipolar PFA (500 V, 20 μs for 50 pulses) was applied to eight porcine ventricles, with CF categorized as standard (5–15 g), high (16–30 g), or very high (> 30 g) using the CARTO 3 system. PFA lesions were assessed by gross pathology, histology, and post-ablation voltage amplitude. Additionally, a vegetal model using oscillating russet potatoes replicated the motion of a beating heart to compare lesion parameters under dynamic conditions and various PFA configurations (monopolar vs. bipolar).

Results

A total of 61 in vivo bipolar PFA lesions across all groups were analyzed. No significant differences in lesion surface diameter, depth, or volume were found among CF groups. In the vegetal model, monopolar setting had a better correlation between CF and lesion depth compared to bipolar setting. In addition, oscillations and catheter position (perpendicular or parallel) significantly affected lesion dimensions.

Conclusion

Increasing CF has a minimal effect on the size of acute bipolar PFA lesions in the porcine ventricle, suggesting that, for bipolar PFA, adequate CF is more critical than its intensity in a beating heart. For monopolar PFA, greater CF can impact lesion depth.