Virtual electrode effects in a bidomain model with electroporating membrane

This study examines the effects of electroporation in a computer simulation of the response of a two-dimensional slice of myocardium to electrical stimulation. The multicellular, syncytial cardiac tissue is represented by the bidomain model. Electroporation is incorporated in the membrane behavior through changes in the membrane conductance. The conductance increases at a rate that depends exponentially on the square of the transmembrane potential. The time course of the shock-induced transmembrane potential distribution in a slice of myocardium with electroporating membrane is compared to one without electroporation. The differences in magnitude and spatial extent of the regions of direct membrane polarization (the virtual electrodes) are identified