Influence of Na/Ca exchange stoichiometry on model cardiac action potentials

Cardiac action potential simulations were done with the stoichiometry of the Na/Ca exchanger set a 4: 1. Using the Hilgemann-Noble (1987) model, this stoichiometry reduces the resting potential unless regulation by intracellular calcium is incorporated. The K(d) required for such regulation is consistent with current experimental estimates of this parameter.