Numerical computations of cardiac AP using level set based geometries

This article proposes two avenues to help improve the realism of numerical computations for cardiac electrophysiology while maintaining manageable computational resources. We first propose an asymptotic analysis to adjust the parameters and use a simple two-variable ionic model to reproduce the main characteristics of the cardiac action potential (AP) in various myocardial regions. This ionic model is embedded in the bidomain model that is used to propagate the AP in the heart. Our second contribution is a finite element method that couples the heart with the torso in a single variational formulation and allows non body fitted meshes at the interface between the myocardium and the torso/ventricle cavities. This interface is described through a level-set function obtained from the segmentation of patient medical images. Using a 2D test case, we compare the use of body-fitted and non body-fitted meshes and analyze the impact of both approaches on the accuracy of the solutions, including an anisotropic mesh adaptation strategy.