A theoretical study of synchronizations of two myocardial cells

Synchronizations of two myocardial cells with electrical coupling are studied based on the model proposed by McAllister, Noble & Tsien (1975) for the electical activity of cardiac Purkinje fibers. Characteristic features of the synchronizations are predicted against physiological parameters by means of a quasi linear approximation and numerical integrations. There exists a critical value for synchronization regarding the phase difference between paired cells, which depends on the size of the junction resistance and the membrane capacitance. After synchronization the steady value of the phase difference proportionally increases as the junction resistance is increased. The synchronized frequency appears between the initial frequencies of paired cells. These fundamental characteristics can be applied to two aggregates of heart cells as well as heart cells other than those from Purkinje fibers. General discussion comparing with experimental data is given.