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Chaos 4, 461 (1994); http://dx.doi.org/10.1063/1.166024 (12 pages)

Electrical alternans and spiral wave breakup in cardiac tissue

Alain Karma

Physics Department, Northeastern University, Boston, Massachusetts 02115

(Received 2 June 1994; accepted 14 July 1994)

This paper reports the results of a theoretical investigation of spiral wave breakup in model equations of action potential propagation in cardiac tissue. A general formulation of these equations is described in which arbitrary experimentally determined restitution and dispersion curves can in principle be fitted. Spiral wave behavior is studied in two‐dimension as a function of a parameter Re which controls the steepness of the restitution curve at short diastolic intervals. Spiral breakup is found to occur when the minimum period Tmin, below which a periodically stimulated tissue exhibits alternans in action potential duration, exceeds by a finite amount the spiral rotation period TS. At this point, oscillations in action potential duration are of sufficiently large amplitude to cause a spontaneous conduction block to form along the wavefront. The latter occurs closer to the initiation point of reentry (spiral tip) with increasing steepness and, hence, in smaller tissue sizes. Spiral breakup leads to a spatially disorganized wave activity which is always transient, except for tissues larger than some minimum size and within a very narrow range of Re which increases with dispersion.  

KEYWORDS and PACS

PACS

  • 87.19.-j

    Properties of higher organisms

  • 87.10.-e

    General theory and mathematical aspects

ARTICLE DATA

PUBLICATION DATA

ISSN

1054-1500 (print)  
1089-7682 (online)

For access to fully linked references, you need to log in.
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    M. Courtemanche, L. Glass, and J. P. Keener, Phys. Rev. Lett. 70, 2182 (1993).

    M. Baer and M. Eiswrith, Phys. Rev. E 48, R1635 (1993).


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