The Dynamics of Sustained Reentry in a Loop Model with Discrete Gap Junction Resistance.pdfVIP

The Dynamics of Sustained Reentry in a Loop Model with Discrete Gap Junction Resistance Wei Chen,1, ∗ Mark Potse,2, † and Alain Vinet3, ‡ 1Department of Physioloy, Institute of Biomedical Engineering, Universit´e 2Department of Physiology, Institute of Biomedical Engineering, Universit´e de Montr´eal, Canada and Centre de Recherche de l’Hˆopital du Sacr´e-Coeur de Montr´eal 7 3 0 Department of Physiology, Institute of Biomedical Engineering, Universit´e de Montr´eal, 0 Canada and Centre de Recherche de l’Hˆopital du Sacr´e-Coeur de Montr´eal 2 (Dated: February 6, 2008) r Dynamics of reentry are studied in a one dimensional loop of model cardiac cells with discrete a intercellular gap junction resistance (R). Each cell is represented by a continuous cable with ionic M current given by a modified Beeler-Reuter formulation. For R below a limiting value, propagation is found to change from period-1 to quasi-periodic (QP ) at a critical loop length (Lcrit) that decreases 5 with R. Quasi-periodic reentry exists from Lcrit to a minimum length (Lmin ) that is also shortening 2 with R. The decrease of Lcrit (R) is not a simple scaling, but the bifurcation can still be predicted from the slope of the restitution curve giving the duration of the action potential as a function of ] l