Comparative effects of amiodarone, perhexiline and bepridil on the cardiac rhythms of the unanesthetized dog in chronic heart block.

The effects of amiodarone, perhexiline and bepridil, which decrease effort cardioacceleration although they have no adrenergic beta blocking properties, were studied in the unanesthetized dog in chronic heart block. All three products decreased atrial rate in a durable way after an initial phase of tachycardia. Amiodarone had no depressant effect on idioventricular rate; however, this was significantly slowed by the other two compounds.