Simulations of Optical Mapping During Electroporation

Experiments using optical mapping suggest that electroporation occurs in cardiac tissue when the transmembrane potential, Vm, is observed to be significantly less than ± 400 mV. Our hypothesis, which we test by numerical simulation, is that Vmis greater than ± 400 mV at the tissue surface, but optical mapping underestimates Vmbecause it averages over depth. Results indicate a significant underestimation of Vm. Experimental studies indicate a depolarization of the resting transmembrane potential, V rest, after a strong shock. In a homogeneous model, electroporation only occurs near the tissue surface. Just as Vmduring the stimulus is underestimated due to averaging, we hypothesize that the depolarization of Vrestis also underestimated.