Control of rotating waves in cardiac muscle: analysis of the effect of an electric field.
The effect of an electric field on rotating waves in cardiac muscle is considered from a theoretical point of view. A model of excitation propagation taking into account the cellular structure of the heart is presented and studied. The application of a direct current electric field along the cardiac tissue is known to induce changes in membrane potential which decay exponentially with distance. Investigation of the model shows that the electric field induces a gradient of potential inside a cell which does not decay with distance, and results in modification of excitation propagation which extends a considerable distance from the electrodes. In two dimensions, it induces a drift of rotating waves. The effect of the electric field on propagation velocity and on rotating waves cannot be obtained in any arbitrary models of cardiac muscle. For an electric field of about 1 V cm-1 and junctional resistances of about 20 M omega, the change in velocity of propagation can be up to several percent, resulting in a drift velocity of rotating waves of the order of 1 cm s-1. To test these predictions, experiments with cardiac preparations are proposed.
Pumir
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A
Institut Non Linéaire de Nice, CNRS, Valbonne, France.
Plaza
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F
Krinsky
V I
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D000818:Animals; D004574:Electromagnetic Fields; D004594:Electrophysiology; D006321:Heart / Q000502:physiology*; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000166:cytology