A Comparison of Monodomain and Bidomain Reaction-Diffusion Models for Action Potential Propagation in the Human Heart

TLDR

A bidomain reaction‑diffusion model of the human heart was developed and compared with a compatible monodomain model across empty isolated hearts and fluid‑filled ventricles, simulating both sinus rhythm and ectopic activation. The bidomain model required 2 days on 32 processors, propagated activation 2 % faster, and produced electrograms indistinguishable from the monodomain model, showing that monodomain models are adequate for studying action‑potential propagation in the human heart without applied currents.

Abstract

A bidomain reaction-diffusion model of the human heart was developed, and potentials resulting from normal depolarization and repolarization were compared with results from a compatible monodomain model. Comparisons were made for an empty isolated heart and for a heart with fluid-filled ventricles. Both sinus rhythm and ectopic activation were simulated. The bidomain model took 2 days on 32 processors to simulate a complete cardiac cycle. Differences between monodomain and bidomain results were extremely small, even for the extracellular potentials, which in case of the monodomain model were computed with a high-resolution forward model. Propagation of activation was 2% faster in the bidomain model than in the monodomain model. Electrograms computed with monodomain and bidomain models were visually indistinguishable. We conclude that, in the absence of applied currents, propagating action potentials on the scale of a human heart can be studied with a monodomain model.