title: Fast propagation regions cause self-sustained reentry in excitable media.
abstract: Self-sustained waves of electrophysiological activity can cause arrhythmia in the heart. These reentrant excitations have been associated with spiral waves circulating around either an anatomically defined weakly conducting region or a functionally determined core. Recently, an ablation procedure has been clinically introduced that stops atrial fibrillation of the heart by destroying the electrical activity at the spiral core. This is puzzling because the tissue at the anatomically defined spiral core would already be weakly conducting, and a further decrease should not improve the situation. In the case of a functionally determined core, an ablation procedure should even further stabilize the rotating wave. The efficacy of the procedure thus needs explanation. Here, we show theoretically that fundamentally in any excitable medium a region with a propagation velocity faster than its surrounding can act as a nucleation center for reentry and can anchor an induced spiral wave. Our findings demonstrate a mechanistic underpinning for the recently developed ablation procedure. Our theoretical results are based on a very general and widely used two-component model of an excitable medium. Moreover, the important control parameters used to realize conditions for the discovered phenomena are applicable to quite different multicomponent models.
authors.affiliation: Max-Planck-Institute for Dynamics and Self-Organization, 37077 Goettingen, Germany.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zykov
authors.affiliation: Max-Planck-Institute for Dynamics and Self-Organization, 37077 Goettingen, Germany.
authors.forename: Alexei
authors.initials: A
authors.lastname: Krekhov
authors.affiliation: Max-Planck-Institute for Dynamics and Self-Organization, 37077 Goettingen, Germany; eberhard.bodenschatz@ds.mpg.de.|German Center for Cardiovascular Research, partner site Göttingen, 37099 Goettingen, Germany.|Institute for Nonlinear Dynamics, University of Göttingen, 37077 Goettingen, Germany.|Cornell University, Ithaca, NY 14853.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Bodenschatz
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D001921:Brain / Q000502:physiology; D055724:Electrophysiological Phenomena; D006321:Heart / Q000502:physiology; D006801:Humans; D008962:Models, Theoretical
keywords: ablation; cardiology; excitable media; reentry; spirals