AuthorsK. H. Jæger, A. G. Edwards, A. D. McCulloch and A. Tveito
TitleProperties of cardiac conduction in a cell-based computational model
AfilliationScientific Computing
Project(s)Department of Computational Physiology
StatusPublished
Publication TypeJournal Article
Year of Publication2019
JournalPLoS Computational Biology
Volume15
Issue5
Numbere1007042
Date Published05/2019
PublisherPublic Library of Science
Abstract

The conduction of electrical signals through cardiac tissue is essential for maintaining the function of the heart, and conduction abnormalities are known to potentially lead to life-threatening arrhythmias. The properties of cardiac conduction have therefore been the topic of intense study for decades, but a number of questions related to the mechanisms of conduction still remain unresolved. In this paper, we demonstrate how the so-called EMI model may be used to study some of these open questions. In the EMI model, the extracellular space, the cell membrane, the intracellular space and the cell connections are all represented as separate parts of the computational domain, and the model therefore allows for study of local properties that are hard to represent in the classical homogenized bidomain or monodomain models commonly used to study cardiac conduction. We conclude that a non-uniform sodium channel distribution increases the conduction velocity and decreases the time delays over gap junctions of reduced coupling in the EMI model simulations. We also present a theoretical optimal cell length with respect to conduction velocity and consider the possibility of ephaptic coupling (i.e. cell-to-cell coupling through the extracellular potential) acting as an alternative or supporting mechanism to gap junction coupling. We conclude that for a non-uniform distribution of sodium channels and a sufficiently small intercellular distance, ephaptic coupling can influence the dynamics of the sodium channels and potentially provide cell-to-cell coupling when the gap junction connection is absent.

URLhttps://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1007042
DOI10.1371/journal.pcbi.1007042
Citation Key26640