Biophysical Journal 65: 1775-1787 (1993)
© 1993 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Starmer, C F Articles by Krinsky, V I Search for Related Content PubMed PubMed Citation Articles by Starmer, C F Articles by Krinsky, V I

Vulnerability in an excitable medium: analytical and numerical studies of initiating unidirectional propagation.

Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina 27710.

ABSTRACT

Cardiac tissue can display unusual responses to certain stimulation protocols. In the wake of a conditioning wave of excitation, spiral waves can be initiated by applying stimuli timed to occur during a period of vulnerability (VP). Although vulnerability is well known in cardiac and chemical media, the determinants of the VP and its boundaries have received little theoretical and analytical study. From numerical and analytical studies of reaction-diffusion equations, we have found that 1) vulnerability is an inherent property of Beeler-Reuter and FitzHugh-Nagumo models of excitable media; 2) the duration of the vulnerable window (VW) the one-dimensional analog of the VP, is sensitive to the medium properties and the size of the stimulus field; and 3) the amplitudes of the excitatory and recovery processes modulate the duration of the VW. The analytical results reveal macroscopic behavior (vulnerability) derived from the diffusion of excitation that is not observable at the level of isolated cells or single reaction units.

This article has been cited by other articles:

				Z. Qu, A. Garfinkel, and J. N. Weiss Vulnerable Window for Conduction Block in a One-Dimensional Cable of Cardiac Cells, 1: Single Extrasystoles Biophys. J., August 1, 2006; 91(3): 793 - 804. [Abstract] [Full Text] [PDF]

				A. Pumir, A. Arutunyan, V. Krinsky, and N. Sarvazyan Genesis of Ectopic Waves: Role of Coupling, Automaticity, and Heterogeneity Biophys. J., October 1, 2005; 89(4): 2332 - 2349. [Abstract] [Full Text] [PDF]

				A. G. KLEBER and Y. RUDY Basic Mechanisms of Cardiac Impulse Propagation and Associated Arrhythmias Physiol Rev, April 1, 2004; 84(2): 431 - 488. [Abstract] [Full Text] [PDF]

				A. Arutunyan, A. Pumir, V. Krinsky, L. Swift, and N. Sarvazyan Behavior of ectopic surface: effects of {beta}-adrenergic stimulation and uncoupling Am J Physiol Heart Circ Physiol, December 1, 2003; 285(6): H2531 - H2542. [Abstract] [Full Text] [PDF]

				C.F. Starmer, A.O. Grant, and T.J. Colatsky What happens when cardiac Na channel function is compromised? 2. Numerical studies of the vulnerable period in tissue altered by drugs Cardiovasc Res, March 15, 2003; 57(4): 1062 - 1071. [Abstract] [Full Text] [PDF]

				C.F. Starmer, T. J. Colatsky, and A. O. Grant What happens when cardiac Na channels lose their function? 1 - Numerical studies of the vulnerable period in tissue expressing mutant channels Cardiovasc Res, January 1, 2003; 57(1): 82 - 91. [Abstract] [Full Text] [PDF]

				Members of the Sicilian Gambit New Approaches to Antiarrhythmic Therapy, Part I: Emerging Therapeutic Applications of the Cell Biology of Cardiac Arrhythmias Circulation, December 4, 2001; 104(23): 2865 - 2873. [Abstract] [Full Text] [PDF]

				Members of the Sicilian Gambit New approaches to antiarrhythmic therapy: emerging therapeutic applications of the cell biology of cardiac arrhythmias Cardiovasc Res, December 1, 2001; 52(3): 345 - 360. [Abstract] [Full Text] [PDF]

				A. Arutunyan, D. R. Webster, L. M. Swift, and N. Sarvazyan Localized injury in cardiomyocyte network: a new experimental model of ischemia-reperfusion arrhythmias Am J Physiol Heart Circ Physiol, April 1, 2001; 280(4): H1905 - H1915. [Abstract] [Full Text] [PDF]

				S. Nattel Experimental evidence for proarrhythmic mechanisms of antiarrhythmic drugs Cardiovasc Res, March 1, 1998; 37(3): 567 - 577. [Abstract] [Full Text] [PDF]

				C. F. Starmer, D. N. Romashko, R. S. Reddy, Y. I. Zilberter, J. Starobin, A. O. Grant, and V. I. Krinsky Proarrhythmic Response to Potassium Channel Blockade : Numerical Studies of Polymorphic Tachyarrhythmias Circulation, August 1, 1995; 92(3): 595 - 605. [Abstract] [Full Text]