Model Status

This is a code and units checked version of the model including two variants - A and B - with different formulations for the transient chloride current r gate. The kinetics for this gate in Model B come from an extensive study by Fozzard and Hiraoka. Results using model A are very dependent on initial conditions. Model B has a notch which is less frequency labile than that of model A. This is model A. The model runs in both OpenCell and COR to replicate the published results. The units have been checked and are consistent.

Model Structure

Following Denis Noble's 1962 model of cardiac action potentials in Purkinje fibres, the next significant development in cardiac membrane modelling occurred when R.E. McAllister, D. Noble and R.W. Tsien (1975) published a paper which formulated new ionic current equations based on new experimental data. The description of the kinetics of the currents is still based on the Hodgkin-Huxley formalism, but the currents themselves incorporate some significant new changes, and the total ionic current is broken down into nine discrete, individual ionic fluxes (see the figure below).

The complete original paper reference is cited below:

Reconstruction of the Electrical Activity of Cardiac Purkinje Fibres, McAllister, R.E. Noble, D. and Tsien, R.W. 1975, Journal of Physiology, 251, 1-59. PubMed ID: 1185607