Class III actions in an experimental model of ventricular tachycardia.

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.

Cite this paper

@article{Brugada1993ClassIA, title={Class III actions in an experimental model of ventricular tachycardia.}, author={Josep Brugada and Lucas V. A. Boersma and Francesc Navarro-L{\'o}pez and Maurits A. Allessie}, journal={European heart journal}, year={1993}, volume={14 Suppl H}, pages={50-5} }