Evaluating exponential integrators for Markov chain ion channel models

We evaluate the accuracy and efficiency of an exponential integrator method applied to a cardiac excitation model with numerically stiff Markov chain (MC) description of ionic channels, namely Ryanodine receptor (RyR) and L-type calcium channel ICa(L). If solved by explicit methods such as forward Euler (FE), the stability constraints for these MC models require very small time steps.