Fitting membrane resistance in single cardiac myocytes reduces variability in parameters

Mathematical models of single cardiac myocytes have a valuable role in driving progress in cardiac physiology and in exploring the electrophysiological mechanisms underlying heart function. Most of these models are used to mimic the results of experimentally observed biological phenomena measured in animal models, and can also provide quantitative insights into natural processes. Adjusting parameters in an ionic model to reproduce experimental behaviour is difficult. Mostly, researchers fit the only the net current to reproduce an action potential (AP) shape. However, even with an excellent AP match in the single cell, tissue behaviour can be vastly different. We hypothesize that this uncertainty can be reduced by additionally fitting R_m.