title: Coexisting chaotic and multi-periodic dynamics in a model of cardiac alternans.
abstract: The spatiotemporal dynamics of cardiac tissue is an active area of research for biologists, physicists, and mathematicians. Of particular interest is the study of period-doubling bifurcations and chaos due to their link with cardiac arrhythmogenesis. In this paper, we study the spatiotemporal dynamics of a recently developed model for calcium-driven alternans in a one dimensional cable of tissue. In particular, we observe in the cable coexistence of regions with chaotic and multi-periodic dynamics over wide ranges of parameters. We study these dynamics using global and local Lyapunov exponents and spatial trajectory correlations. Interestingly, near nodes-or phase reversals-low-periodic dynamics prevail, while away from the nodes, the dynamics tend to be higher-periodic and eventually chaotic. Finally, we show that similar coexisting multi-periodic and chaotic dynamics can also be observed in a detailed ionic model.
authors.affiliation: Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors.forename: Per Sebastian
authors.initials: PS
authors.lastname: Skardal
authors.affiliation: Department of Applied Mathematics, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Juan G
authors.initials: JG
authors.lastname: Restrepo
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D003198:Computer Simulation; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D017711:Nonlinear Dynamics; D009991:Oscillometry / Q000379:methods