Off-site control of repolarization alternans in ...



Title Off-site control of repolarization alternans in cardiac fibers
Author(s) Trine Krogh-Madsen, Alain Karma, Mark L. Riccio, Peter N. Jordan, David J. Christini, Robert F.,,Jr Gilmour
Journal Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
Date 2010
Volume 81
Issue 1
Start page 011915
End page 011915
Abstract Repolarization alternans, a beat-to-beat alternation in action potential duration, has been putatively linked to the onset of cardiac reentry. Anti-alternans control strategies can eliminate alternans in individual cells by exploiting the rate dependence of action potential duration. The same approach, when applied to a common measuring/stimulating site at one end of a cardiac fiber, has been shown to have limited spatial efficacy. As a first step toward spatially distributed electrode control systems, we investigated 'off-site' control in canine Purkinje fibers, in which the recording and control sites are different. We found experimentally that alternans can be eliminated at, or very near, the recording site, and that varying the location of the recording site along the fiber causes the node (the location with no alternans) to move along the fiber in close proximity to the recording site. Theoretical predictions based on an amplitude equation B. Echebarria and A. Karma, Chaos 12, 923 (2002)] show that those findings follow directly from the wave nature of alternans: the most unstable mode of alternans along the fiber is a wave solution of a one-dimensional Helmholtz equation with a node position that only deviates slightly from the recording site by an amount dependent on electrotonic coupling. Computer simulations using a Purkinje fiber model confirm these theoretical and experimental results. Although off-site alternans control does not suppress alternans along the entire fiber, our results indicate that placing the node away from the stimulus site reduces alternans amplitude along the fiber, and may therefore have implications for antiarrhythmic strategies based on alternans termination.
DOI 10.1103/physreve.81.011915
Use/Reproduction Contact Publisher

Using APA 6th Edition citation style.

[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]

Times viewed: 447

Adding this citation to "My List" will allow you to export this citation in other styles.