Ensuring stability in models of atrial kinetics

The membrane kinetics of human atrial myocytes as formulated by Courtemanche, Ramirez and Nattel has been studied while focussing on its progression toward stationary solutions during long term repetitive stimulation. An algorithm is presented for finding the initial settings for all state variables on the basis of those assumed for the transmembrane potential V_m and the intracellular concentrations of the ions involved: [Na⁺], [K⁺], and [Ca²⁺]. The algorithm may be used for testing the feasibility of yielding stationarity for any proposed combination of these values, as well as for any perturbation of the model parameters.