Which of the following drugs causes an increase in the effective refractory period of the atrioventricular (AV) node?
Amiodarone causes a decrease in the sinus rate and an increase in the effective refractory period in the atrium, the AV node, and the ventricle. The pharmacology of amiodarone is complex and incompletely understood.
bretylium
amiodarone
procainamide
quinidine
C.V.S.