Section: Research Program

Cardiac Electrophysiology at the Microscopic Scale

Numerical models of cardiac physiology are based on the approximation of a perfect muscle using homogenisation method. However, due to the age and due to some cardiomyopathies, the cellular structure of the tissue changes. These modifications give rise to life-threatening arrhythmias. For our research on this subject and with cardiologists of the IHU LIRYC Bordeaux, we aim to design and implement models that describe the strong heterogeneity of the tissue at the cellular level and numerically explore the mechanisms of these diseases.

The problem is that literature on this type of model is still very poor and existing models are bidimensionels or limited to idealised geometries. We propose an approach in opposition with the usual homogenisation way. We want to describe the muscle as a system of three-dimensional cells, whose dynamics is given by the modeling of ion fluxes across cell membranes in equilibrium with the electrostatic potentials in the intracellular and extracellular environments.

The goals are to design, analyse, and explore numerically a model of cardiac electrophysiology at a level of discretisation of about $1\mu m$ (that means 10 to 100 times smaller than the size of cardiomyocytes), develop model and its numerical discretisation, define realistic geometries or actual cells.

Issues are scale simulations for thousands of cores to take into account thousands or tens of thousands cells. For this, a hybrid parallelism approach OpenMP and MPI will be considered.