The role of extracellular potassium transport in computer models of the ischemic zone

Ischemic heart disease is associated with large mortality and morbidity. Understanding of the relations between coronary artery occlusion, geometry of the ischemic region, physiology of ischemia, and the resulting changes in electrocardiogram (ECG) leads and catheter signals is important to support diagnosis and treatment. Computer models play an important role in understanding ischemia, by linking experimental to clinical results. In this paper we argue that the observed transport of extracellular potassium should be represented in such models. We used a diffusion equation to describe the transport mechanism. This model reproduced the measured spatial distribution of potassium, and its temporal development. We discuss the role of potassium transport next to other aspects of ischemia: the mechanism of changes in action potential and ECG, cellular coupling, anisotropic bidomain tissue conductivity, and the geometry of the ischemic zone. Computational resources for this work were provided by the Réseau québécois de calcul de haute performance (RQCHP). M. Potse was supported by a postdoctoral research award from the Groupe de recherche en sciences et technologie biomédicale (GRSTB), école Polytechnique and Université de Montréal; and by the Research Center of Sacré-Coeur Hospital, Montréal, QC, Canada.