Generation and propagation of ectopic beats induced by spatially localized Na–K pump inhibition in atrial network models

Abstract

A biophysically detailed two-dimensional network model of the cardiac atrium has been implemented on the Thinking Machines massively parallel CM-5 supercomputer. The model is used to study the effects of spatially localized inhibition of the Na--K pump. Na overloading produced by pump inhibition can induce spontaneous, propagating ectopic beats within the network. At a cell-to-cell coupling value yielding a realistic plane wave conduction velocity of 0.6 m s$^{-1}$, pump inhibition in roughly 1000 cells can induce propagating ectopic beats in a 512 $\times $ 512 lattice of cells.