Impact of application repetition on Joule heating and lesion formation using a circular-shaped pulsed field catheter.

Introduction: Pulsed field ablation (PFA) is a non-thermal ablation modality, but repeated high-voltage applications can still cause Joule heating at the electrode-tissue interface. We evaluated the effects of application repetition and inter-application intervals on temperature rise and lesion depth using a circular-shaped PFA catheter.

Methods and results: In an in vitro potato model, a circular-shaped PFA catheter was tested under five settings: 1×, 2×, 2× with a 10-s interval, 4×, and 4× with a 10-s interval. Maximum electrode surface temperature was measured using a thermal camera, and lesion depth was assessed by TTC staining (n = 5 per setting). Temperature increased significantly with application repetition and was attenuated by a 10-s interval (overall P < 0.0001). Lesion depth also increased with repetition (overall P < 0.0001), but did not differ significantly between interval and no-interval conditions at equal application numbers.

Conclusion: In this simplified in vitro model, a short inter-application interval was associated with attenuation of temperature rise during repeated PFA delivery, while lesion depth was not significantly reduced.