Models for mechanistic investigations of pacing arrthymogenesis and cardiac tissue structure.

Two-dimensional in silico models have been constructed for investigating electrical dynamics arising due to pacing rates and tissue discontinuities. Discontinuities (structures) are introduced explicitly through flux discontinuities in the intracellular space. These models use isotropic electrophysiological properties with heterogeneity arising solely from tissue structure. Both simplified and tissue-specific structures can be used together with membrane models with varying restitution properties. Stimuli are delivered at increasing pacing rates, and solution restarts enable the investigation of repeat stimulation at any of the rates. Investigations using these models are providing new insights into mechanisms leading to conduction block and arrhythmogenesis in cardiac tissue.