title: A 2D Electromechanical Model of Human Atrial Tissue Using the Discrete Element Method.
abstract: Cardiac tissue is a syncytium of coupled cells with pronounced intrinsic discrete nature. Previous models of cardiac electromechanics often ignore such discrete properties and treat cardiac tissue as a continuous medium, which has fundamental limitations. In the present study, we introduce a 2D electromechanical model for human atrial tissue based on the discrete element method (DEM). In the model, single-cell dynamics are governed by strongly coupling the electrophysiological model of Courtemanche et al. to the myofilament model of Rice et al. with two-way feedbacks. Each cell is treated as a viscoelastic body, which is physically represented by a clump of nine particles. Cell aggregations are arranged so that the anisotropic nature of cardiac tissue due to fibre orientations can be modelled. Each cell is electrically coupled to neighbouring cells, allowing excitation waves to propagate through the tissue. Cell-to-cell mechanical interactions are modelled using a linear contact bond model in DEM. By coupling cardiac electrophysiology with mechanics via the intracellular Ca(2+) concentration, the DEM model successfully simulates the conduction of cardiac electrical waves and the tissue's corresponding mechanical contractions. The developed DEM model is numerically stable and provides a powerful method for studying the electromechanical coupling problem in the heart.
authors.affiliation: Engineering Department, Lancaster University, Lancaster LA1 4YR, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Brocklehurst
authors.affiliation: Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Ismail
authors.initials: I
authors.lastname: Adeniran
authors.affiliation: School of Civil Engineering, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Dongmin
authors.initials: D
authors.lastname: Yang
authors.affiliation: School of Civil Engineering, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Yong
authors.initials: Y
authors.lastname: Sheng
authors.affiliation: Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Henggui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Engineering Department, Lancaster University, Lancaster LA1 4YR, UK.
authors.forename: Jianqiao
authors.initials: J
authors.lastname: Ye
mesh_terms: D000200:Action Potentials; D016275:Atrial Function / Q000502:physiology*; D055724:Electrophysiological Phenomena; D006325:Heart Atria; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology; D009210:Myofibrils / Q000502:physiology