Dr.-Ing. Cristian Barrios

Shaavina Ryvi

Anisotropy in cardiac tissue is often overlooked in research and diagnostic tools, including Pulsed Field Ablation (PFA) simulations, despite its crucial role in how electric fields interact with cells. Cardiomyocytes are not randomly oriented; their alignment strongly influences their electroporation response, meaning that the angle of bipolar electrodes can significantly affect treatment outcomes. Neglecting this factor can lead to oversimplified models and less effective therapies. Previous in vitro and in silico studies have examined the impact of cell orientation for monophasic pulses across a wide range of durations, from nanoseconds to milliseconds. Interestingly, the preferential orientation of electroporation changes with pulse duration: nanosecond pulses predominantly affect cells oriented perpendicular to the electric field, whereas millisecond pulses preferentially affect parallel cells. For intermediate pulse durations, the orientation dependence appears to shift polarity multiple times, rather than following a single clear transition point. Surprisingly the orientation dependence does not follow a simple monotonic trend; instead, the preferentially affected orientation alternates with pulse duration, resembling a switching or oscillatory pattern. Scuderi et al. used a computer model of subcellular resolution to investigate these phenomena. The present work extends these studies to high-resolution simulations of multiple coupled cells where cardiomyocytes are explicitly represented in the discretised space, providing new insights into the role of anisotropy in pulsed field ablation at the tissue level.