Determinants of acute irreversible electroporation lesion characteristics after pulsed field ablation: the role of voltage, contact, and adipose interference

Aims Pulsed field ablation (PFA) is a non-thermal ablative approach in which cardiomyocyte death is obtained through irreversible electroporation (IRE). Data correlating the biophysical characteristics of IRE and lesion characteristics are limited. The aim of this study was to assess the effect of different procedural parameters [voltage, number of cycles (NoCs), and contact] on lesion characteristics in a vegetal and animal model for IRE. Methods and results Two hundred and four Russet potatoes were used. Pulsed field ablation lesions were delivered on 3 cm cored potato specimens using a multi-electrode circular catheter with its dedicated IRE generator. Different voltage (from 300 to 1200 V) and NoC (from 1 to 5x) protocols were used. The impact of 0.5 and 1 mm catheter-to-specimen distances was tested. A swine animal model was then used to validate the results observed in the vegetable model. The association between voltage, the NoCs, distance, and lesion depth was assessed through linear regression. An almost perfect linear association between lesion depth and voltage was observed (R-2 = 0.95; P < 0.001). A similarly linear relationship was observed between the NoCs and the lesion depth (R-2 = 0.73; P < 0.001). Compared with controls at full contact, a significant dampening on lesion depth was observed at 0.5 mm distance (1000 V 2x: 2.11 +/- 0.12 vs. 0.36 +/- 0.04, P < 0.001; 2.63 +/- 0.10 vs. 0.43 +/- 0.08, P < 0.001). No lesions were observed at 1.0 mm distance. Conclusion In a vegetal and animal model for IRE assessment, PFA lesion characteristics were found to be strongly dependent on voltage settings and the NoCs, with a quasi-linear relationship. The lack of catheter contact was associated with a dampening in lesion depth. [GRAPHICS] .