Berlin 2012 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 19: Nonlinear Dynamics of the Heart: Contributed talks to focus session
DY 19.2: Vortrag
Mittwoch, 28. März 2012, 15:15–15:30, MA 001
On the possible generation of atrial fibrillation by mutually interacting excitation sources — Claudia Lenk1, Gunnar Seemann2, •Mario Einax3, and Philipp Maass3 — 1Institut für Chemie, Technische Universität Ilmenau, Germany — 2Institut für Biomedizinische Technik, Karlsruhe Institute of Technology, Germany — 3Fachbereich Physik, Universität Osnabrück, Germany
Atrial fibrillation (AF) is the most common arrhythmia of the heart which, amongst others, strongly increases the risk of stroke. As a possible new generating mechanism of AF we study the interaction of two pacemakers located in separate regions connected by a small bridge. In our setup the sinus node is considered as the primary pacemaker, while the secondary pacemaker is representing self-excitatory sources as ectopic foci and microreentrant circuits, which are often observed in the left atrium of AF patients. Our calculations are based on the model of Bueno-Orovio et al. (BO model) with a specific adaption of parameters to the electrophysiology of the atria. The results are compared to solutions of the more generic FitzHugh-Nagumo (FHN) equations in order to get insight how far mechanisms are specific to electrophysiological peculiarities of the atria. Three different types of irregular excitation patterns with similarities to fibrillatory states can be identified in the FHN model for certain frequency ratios of the two pacemakers, but only one of them is present in the BO model. The reason for the higher robustness of the regular states in the BO model is discussed as well as effects of electrophysiological remodelling on the dynamical excitation patterns.