Cardiac Ablation with Electroporation-Electrolysis (E2): Feasibility and Workflow Towards Dose Planning Using an In Vivo Model

Abstract

The gold standard in atrial fibrillation ablation relies on thermal cell-kill, which carries limitations in efficacy, speed and risk. Electroporation is emerging in cardiac ablation as a fast, non-thermal and tissue-specific alternative. Successful irreversible electroporation (IRE) ablation in tumours has spurred similar use of kilovolt pulses in cardiac ablation. However, high voltages in the heart would compound clinical, technical and regulatory challenges. A novel ablation technique, “E2”, augments low-voltage electroporation with electrolytic cell-kill. A custom E2 ablation system was developed and tested on the in-vivo thigh muscle tissue model of cardiac ablation. E2 was applied on three sheep – anaesthetised and sedated but not paralysed – as either single or two consecutive monophasic pulses each lasting under 100 ms, with peak voltages 350 V to 490 V and peak currents 4.4A to 9.2A, resulting in total delivered energy of 22 J to 42 J. Electrode placement through a custom jig allowed consistent experimental conditions and accurate tissue extraction following sacrifice one hour after the final ablation. H&E showed continuous lesions of at least 4 mm depth below the electrodes, extending radially. There was no inflammation or pathology away from the ablation site. With tolerable muscle contraction comparable to AICD testing and the absence of acute complications, these findings may be clinically relevant for pulmonary vein isolation. Lesions were mapped onto a numerical model, which can inform prototype development and treatment planning. This study validates E2 ablation, preliminary prototyping and establishes a workflow for parametrising electroporation ablation towards endocardial dose optimisation.