title: Cardiac contraction induces discordant alternans and localized block.
abstract: In this paper we use a simplified model of cardiac excitation-contraction coupling to study the effect of tissue deformation on the dynamics of alternans, i.e., alternations in the duration of the cardiac action potential, that occur at fast pacing rates and are known to be proarrhythmic. We show that small stretch-activated currents can produce large effects and cause a transition from in-phase to off-phase alternations (i.e., from concordant to discordant alternans) and to conduction blocks. We demonstrate numerically and analytically that this effect is the result of a generic change in the slope of the conduction velocity restitution curve due to electromechanical coupling. Thus, excitation-contraction coupling can potentially play a relevant role in the transition to reentry and fibrillation.
authors.affiliation: Weierstrass Institute for Applied Analysis and Stochastics Mohrenstrasse 39, 10117 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Radszuweit
authors.affiliation: Departament de Física Aplicada, Universitat Politècnica de Catalunya.BarcelonaTech, Av. Dr. Marañón 44-50, E-08028, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Alvarez-Lacalle
authors.affiliation: Physikalisch-Technische Bundesanstalt, 10587 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bär
authors.affiliation: Departament de Física Aplicada, Universitat Politècnica de Catalunya.BarcelonaTech, Av. Dr. Marañón 44-50, E-08028, Barcelona, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Echebarria
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D003198:Computer Simulation; D056966:Excitation Contraction Coupling / Q000502:physiology; D025461:Feedback, Physiological / Q000502:physiology; D006321:Heart / Q000502:physiology / Q000503:physiopathology; D006329:Heart Conduction System / Q000002:abnormalities / Q000503:physiopathology; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*