1. Class III actions in an experimental model of ventricular tachycardia.
- Author
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Brugada, J., Boersma, L., Navarro-Lopez, F., and Allessie, M.
- Abstract
Simplified models of re-entry may help in our understanding of the electrophysiologic effects of class III drugs. In a model of re-entrant ventricular tachycardia around a ring of epicardium in Langendorff-perfused rabbit hearts, the electrophysiologic effects of class III antiarrhythmic drugs were studied and compared to those of class I drugs.Class III drugs were effective in terminating fast re-entrant ventricular tachycardias. Prolongation of the refractory period without affecting conduction velocity resulted in a closure of the excitable gap and collision of the head of the propagating impulse against its own tail of refractoriness. In slow ventricular tachycardias, despite a similar increase in refractory period, the excitable gap remained large enough to allow perpetuation of the tachycardia. [ABSTRACT FROM PUBLISHER]
- Published
- 1993
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