Speaker
Description
Cardiac ablation is a key procedure for treating arrhythmias, one of the leading causes of death worldwide. While radiofrequency ablation (RFA), based on thermal injury, has long been the clinical standard, pulsed field ablation (PFA) has recently emerged as a promising non-thermal alternative. PFA relies on irreversible electroporation, a microscopic phenomenon in which strong electric fields disrupt the cell membrane, leading to cell death.
Modeling PFA is essential to understand how these microscopic effects translate to the tissue scale and to improve clinical guidance. In this talk, we present a physiologically relevant model specific to cardiac tissue, going beyond the classical Poisson framework with nonlinear conductivity. Our approach is based on the periodic homogenization of a nonlinear microscopic bidomain model, where electroporation is described as a voltage-dependent increase in membrane conductance. The associated two-scale expansion is derived and rigorously justified.
From its leading terms, we obtain an effective macroscopic model and introduce relevant quantities to identify ablated regions. We then investigate clinically relevant scenarios, highlighting the impact of fiber orientation and pulse repetition, and propose an extension accounting for conductivity memory effects between pulses.
