Excitation Wave Propagation in Narrow Passes
Direct physiological evidence [1-4] exists that occurrences of arrhythmia are commonplace in the presence of infarct scars, where regions of normal and excitable myocardium are interspersed with regions of unexcitable myocardium. These regions form narrow and wide pathways for wave propagation and each of these pathways assumes a configuration that can be categorized into a particular type of border geometry.
The concept of critical curvature of the wavefront (introduced in chapter 9) provides a connection between pathway border geometry and the properties of surviving myocardium within the pathway and the appearance of a unidirectional conduction block. The conduction block facilitates the appearance of reentrant arrhythmias, which can in turn, lead to ventricular fibrillation.
KeywordsExcitable Medium Border Zone Space Unit Critical Width Narrow Path
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- 1.de Bakker, J.M., F.J.L. van Capelle, M.J. Janse, A.A. Wilde, R. Coronel, A.E. Becker, K.P. Dingemans, N.M. van Hemel, and R.N. Hauer, Reentry as a cause of ventricular tachycardia in patients with chronic ischemic heart disease: electrophysiologic and anatomic correlation. Circulation, 1988. 77: 589-606.Google Scholar
- 2.Bolick, D.R., D.B. Hackel, K.A. Reimer, and R.E. Ideker, Quantitative analysis of myocardial infarct structure in patients with ventricular tachycardia. Circulation, 1986. 74: 1266-1279.Google Scholar
- 3.Fenoglio Jr., J.J., T.D. Pham, A.H. Harken, L.N. Horowitz, M.E. Josephson, and A.L. Wit, Recurrent sustained ventricular tachycardia: structure and ultrastructure of subendocardial regions in which tachycardia originates. Circulation, 1983. 68: 518–533.Google Scholar
- 4.de Bakker, J.M., R. Coronel, S. Tasseron, A.A. Wilde, T. Opthof, M.J. Janse, F.J. van Capelle, A.E. Becker, and G. Jambroes, Ventricular tachycardia in the infarcted, Langendorff-perfused human heart: role of the arrangement of surviving cardiac fibers. J Am Coll Cardiol, 1990. 15: 1594-1607.CrossRefGoogle Scholar
- 8.Dillon, S.M., M.A. Allessie, P.C. Ursell, and A.L. Wit, Influences of anisotropic tissue structure on reentrant circuits in the epicardial border zone of subacute canine infarcts. Circ Res, 1988. 63: 182-206.Google Scholar
- 9.Zykov, V.S., Analytic estimate of the dependence of excitation wave velocity in a two dimensional excitable medium on the curvature of its front. Biofizika (USSR), 1980. 25: 888- 892.Google Scholar
- 10.Pang, A.T., On Simulating and Visualizing Nonlinear Distributed Parameter Systems Using Massively Parallel Computers, in Computer Science. 1990, University of California, Los Angeles: Los Angeles. p. 155.Google Scholar
- 12.Zykov, V.S., Simulation of Wave Process in Excitable Media. Nonlinear science: theory and applications, ed. A.V. Holden. 1987, Manchester and New York: Manchester University Press.Google Scholar
- 14.Kogan, B.Y., W.J. Karplus, and M.G. Karpoukhin. The effect of boundary conditions and geometry of 2D excitable media on properties of wave propagation. in International Workshop on Dynamism and Regulation in Non-linear Chemical Systems. 1994. Tsukuba, Japan: National Institute of Materials and Chemical Research (Japan). p. 79-81.Google Scholar
- 15.Kogan, B.Y., W.J. Karplus, and B.S. Billet. Excitation wave propagation through narrow pathways. in Spatio-Temporal Organization in Nonequilibrium Systems. 1992. Berlin, Germany: Project Verlag. p. 122-127.Google Scholar