Cardiac electrophysiologic effects of McN-5691, a new calcium-channel blocking antihypertensive agent.

Characterization of the cardiac electrophysiological profile of McN-5691: effects on (a) cardiac conduction and refractoriness in anesthetized dogs, (b) normal, canine Purkinje fiber transmembrane potentials, and (c) slow-response action potentials in guinea pig papillary muscles depolarized with elevated K+. Comparison to verapamil in the same models.