Modulation of Conduction Velocity by Nonmyocytes in the Low Coupling Regime

This paper explores the conditions under which non myocytes, when electrically coupled to myocytes, act as a passive load during the depolarization phase. Using theoretical arguments and numerical simulations in a tissue incorporating fibroblasts, the passive load approximation is shown to be accurate at low coupling conductances ( <2 nS). In this case, the effect on conduction velocity can be expressed as a function of the elevation in resting potential and the coupling only.