Further development of a model for electrical transmission between myocardial cells not connected by low-resistance...

We previously described a model for the electrical transfer of excitation from one cell to the next which utilized the electric field generated in the cleft between the cells. This model was analyzed only for the steady-state condition. In the present paper, we calculate the effects of membrane capacitance on the transmission of an action potential between two adjacent cardiac cells; the junction between cells was composed of two high-resistance excitable membranes separated by a narrow cleft. The parameters varied for this study included the threshold potential and capacitance of the junctional membranes. The calculations indicate that it is somewhat easier to achieve transmission when capacitive effects are included. Thus, the electric field model provides an alternative means of cell-to-cell propagation between myocardial cells which is electrical in nature but does not require the presence of low-resistance connections between cells.