Bifurcations, chaos, and sensitivity to parameter variations in the Sato cardiac cell model

•Detailed evaluation of dynamical features of an ionic cardiac cell model focusing on chaotic action potentials, bifurcation scenarios, and coexistence of attractors.•Evaluation of the model’s robustness with respect to (small) parameter change (deviations from standard values).•Classification of all 177 model parameters in four categories with respect to their impact on the model dynamics.•Critical discussion of model robustness and parameter selection. The dynamics of a detailed ionic cardiac cell model proposed by Sato et al. (2009) is investigated in terms of periodic and chaotic action potentials, bifurcation scenarios, and coexistence of attractors. Starting from the model’s standard parameter values bifurcation diagrams are computed to evaluate the model’s robustness with respect to (small) parameter changes. While for some parameters the dynamics turns out to be practically independent from their values, even minor changes of other parameters have a very strong impact and cause qualitative changes due to bifurcations or transitions to coexisting attractors. Implications of this lack of robustness are discussed.