Effects of Adrenergic P-Blockers and a Membrane Stabilizing Agent on Ouabain-Induced Cardiac Arrhythmias in Anaesthetized Guinea Pigs

Abstract
The antiarrhythmic effects of dl-propranolol, d-propranolol, metoprolol and lidocaine against ouabain-induced cardiac arrhythmias were studied. Apparently contrary to findings in the dog, the effects of the adrenergic .beta.-blockers against ouabain-arrhythmias in guinea pigs were due to .beta.-blocking activity and not the membrane-stabilizing activity of the compounds. The cardioselective .beta.-blocker metoprolol was more or equally effective as dl-propranolol against ouabain-induced arrhythmias in guinea pigs.