title: Spiral-wave dynamics in a mathematical model of human ventricular tissue with myocytes and Purkinje fibers.
abstract: We present systematic numerical studies of the possible effects of the coupling of human endocardial and Purkinje cells at cellular and two-dimensional tissue levels. We find that the autorhythmic-activity frequency of the Purkinje cell in a composite decreases with an increase in the coupling strength; this can even eliminate the autorhythmicity. We observe a delay between the beginning of the action potentials of endocardial and Purkinje cells in a composite; such a delay increases as we decrease the diffusive coupling, and eventually a failure of transmission occurs. An increase in the diffusive coupling decreases the slope of the action-potential-duration-restitution curve of an endocardial cell in a composite. By using a minimal model for the Purkinje network, in which we have a two-dimensional, bilayer tissue, with a layer of Purkinje cells on top of a layer of endocardial cells, we can stabilize spiral-wave turbulence; however, for a sparse distribution of Purkinje-ventricular junctions, at which these two layers are coupled, we can also obtain additional focal activity and many complex transient regimes. We also present additional effects resulting from the coupling of Purkinje and endocardial layers and discuss the relation of our results to the studies performed in anatomically accurate models of the Purkinje network.
authors.affiliation: International Institute of Information Technology (IIIT-Bhubaneswar), Gothapatna, Po: Malipada, Bhubaneswar 751003, India.
authors.forename: Alok Ranjan
authors.initials: AR
authors.lastname: Nayak
authors.affiliation: Department of Physics and Astronomy, Gent University, Krijgslaan 281, S9, 9000 Gent, Belgium.|Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Panfilov
authors.affiliation: Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Pandit
mesh_terms: D000200:Action Potentials; D003198:Computer Simulation; D006352:Heart Ventricles / Q000166:cytology; D006801:Humans; D008955:Models, Cardiovascular; D032383:Myocytes, Cardiac / Q000166:cytology / Q000502:physiology*; D010507:Periodicity; D011690:Purkinje Fibers / Q000166:cytology / Q000502:physiology*; D016276:Ventricular Function