MICROCARD 2 project

MICROCARD aims to build software that can simulate cardiac electrophysiology using whole-heart models with sub-cellular resolution, on exascale supercomputers. MICROCARD is a Centre of Excellence, funded by by EuroHPC, to consolidate and improve the results of the project.

• Background

Cardiovascular diseases are the most frequent cause of death worldwide and half of these deaths are due to cardiac arrhythmia, disorders of the heart’s electrical synchronization system. Computer models are essential to understand the behaviour of this complex system and its diseases. These models are already very sophisticated and widely used, but currently they are not powerful enough to take the heart’s (2 billion!) individual cells into account. They must therefore assume that hundreds of cells are doing approximately the same thing. Due to this limitation, current models cannot reproduce the events in aging and structurally diseased hearts, in which reduced electrical coupling leads to large differences in behaviour between neigbouring cells, with possibly fatal consequences.

• Aims

The purpose of the MICROCARD project is to develop software that can simulate the electrical and mechanical behaviour of the heart muscle has existed for a long time, but has almost all relied on homogenization of the cardiac tissue. This means that it does not represent individual cells, but rather treats large numbers of cells as a continuum. This is a very efficient approach, but it has limitations when it comes to simulation of structurally diseased heart muscle, where interactions between individual cells can lead to cardiac arrhythmia. To study such interactions so-called intracellular-membrane-extracellular (EMI) models have been developed. These models explicitly discretize the volumes inside and outside the cells, and the electrically active membrane between them. Until now, EMI models have been very limited in size.Then, MICROCARD also aims to develop an EMI model code that can run on exascale supercomputers, allowing to simulate millions or even billions of cells.

To this end, MICROCARD will work on several topics. It will build on the µCARP code developed by the MICROCARD project (2021-2024). µCARP is an EMI model code based on the community code openCARP.