Acoustic effects during pulsed field ablation: measurement and control of bubble and void formation

Background Pulsed field ablation (PFA) is an emerging treatment option for arrhythmogenic myocardial tissue and solid tumors. PFA uses high voltage pulses to alter the electric potential across cell membranes, creating pores and eventual cell death. Bubble nucleation due to gas evolution at the electrode/electrolyte interface follows the delivery of current from the power generator to the body. Here, we investigate the acoustic effects induced by PFA to maximize the electroporation effect without pressure-driven damage.Methods Acoustic signals created by a PFA probe in saline were measured with a hydrophone. The lethality of PFA was tested in vitro in a 3D tissue mimic to resolve a ratio of cell death area to pressure. Mechanical damage created by PFA was then evaluated by gross measurements in agarose tissue mimics of different stiffness. Electrical resistance was tested with a plant-tissue model.Results Monophasic pulses create smaller pressure waves (p 2 = 0.9898 vs 0.8772).Conclusions Bubble formation and void formation are generally undesirable when using PFA. This paper presents the first characterization of the pressure waves created by PFA and provides strategies for improving an electrical waveform to maximize the electroporation effect without violent acoustic waves.