The Structural Implications of the Linear Electrical Properties of Cardiac Purkinje Strands

An attempt has been made to decide upon the most reasonable equivalent circuit that will describe the passive linear properties of the Purkinje strands of sheep heart muscle. In order to do this, measurements were made of the phase angle of the characteristic admittance as well as the longitudinal impedance, both as functions of frequency. The results of both types of experiments indicate the presence of a longitudinally oriented capacity with a time constant of about 60–70 µsec. It is suspected that this capacity and time constant represent the connection between the cells, both radially and longitudinally. The plasma membrane contains another capacity with a time constant of about 15 msec.