title: Direct activation and defibrillation of cardiac tissue.
abstract: It is shown that inhomogeneity due to gap junctional resistance allows an excitable cable to be directly activated or defibrillated by the application of a large amplitude point stimulus of short duration. Multiple-scale analysis is used to derive a model equation describing the response of the excitable medium to stimuli, and this equation is analyzed to give quantitative estimates of the direct stimulus threshold and the defibrillation threshold. These estimates are shown to be in good agreement with experimental findings.
authors.affiliation: Department of Mathematics, University of Utah, Salt Lake City 84112, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Keener
mesh_terms: D004554:Electric Countershock; D017629:Gap Junctions / Q000502:physiology; D006321:Heart / Q000503:physiopathology*; D006323:Heart Arrest / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008433:Mathematics; D008955:Models, Cardiovascular