title: Critical role of inhomogeneities in pacing termination of cardiac reentry.
abstract: Reentry around nonconducting ventricular scar tissue, a cause of lethal arrhythmias, is typically treated by rapid electrical stimulation from an implantable cardioverter defibrillator. However, the dynamical mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we study the dynamics of pacing in one- and two-dimensional models of anatomical reentry. In a crucial realistic difference from previous studies of such systems, we have placed the pacing site away from the reentry circuit. Our model-independent results suggest that with such off-circuit pacing, the existence of inhomogeneity in the reentry circuit is essential for successful termination of tachycardia under certain conditions. Considering the critical role of such inhomogeneities may lead to more effective pacing algorithms. (c) 2002 American Institute of Physics.
authors.affiliation: Division of Cardiology, Weill Medical College of Cornell University, New York, New York 10021Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Sitabhra
authors.initials: S
authors.lastname: Sinha
authors.forename: Kenneth M.
authors.initials: KM
authors.lastname: Stein
authors.forename: David J.
authors.initials: DJ
authors.lastname: Christini