Simulation of the 1-D cardiac excitation process by varying extracellular potassium concentration and intracellular resistivity

This study deals with the modeling of the spread of excitation along a ventricular cardiac fibre according to the one-dimensional cable theory. The influence of changes of the intracellular axial resistivity R and of the extracellular potassium concentration [K]/sup 0/ on the propagation are investigated. The Luo-Rudy-model is used as membrane model. The intracellular resistivity R consists of the resistivity of the cytoplasm and of the cell-to-cell contact (gap junctions). The phenomenon of the unidirectional block (UDB) can be simulated across an ischemic border zone. The simulation study makes evident, that changes of the R-profile have a more significant effect on the propagation than variations of the [K]/sup 0/-profile.