Electrophysiologically determined quinidine-like actions of a beta-adrenergic blocking agent, 1-(7-indenyloxy)-3-isopropylaminopropane-2-ol hydrochloride (YB-2).

Since 1-(7-indenyloxy)-3-isopropylaminopropane-2-ol hydrochloride (YB-2) has been reported to be a potent beta-adrenergic blocking agent with antiarrhythmic effects, the electrophysiological effects of this compound on guinea-pig and canine heart muscle were examined. YB-2 was found to have typical quinidine-like actions such as decrease in rate of rise of the action potential, prolongation of refractory period and decrease in conduction velocity.