Changes of Ventricular Monophasic Action Potential Duration by Stellate Ganglion Stimulation in Dogs

Publisher Website
Google Scholar
Abstract
Left or right stellate ganglion stimulation resulted in changes of ST segments and T waves of ECG. The effect of .alpha.- and .beta.-adrenergic actions and Ca action on the monophasic action potential duration (APD), i.e., the repolarizing phase of myocardium was studied. In open-chest dogs, right ventricular pacing was performed to avoid acceleration of heart rate by stellate ganglion stimulation. Administration of phentolamine, propranolol or D600 [.alpha.-isopropyl-.alpha.-[(N-methyl-N-homoveratryl)-.gamma.-aminopropyl]-3,4,5-trimethoxyphenyl-acetonitrile] prolonged APD, while hydrazine shortened it. Stellate ganglion stimulation caused a prolongation of APD after infusion of propranolol or hydrazine, and a shortening of APD after infusion of phentolamine, D600 or hydrazine. .alpha.- and .beta.-adrenergic actions and ions can be related to APD in the ventricular myocardium of dogs: apparently, .alpha.-adrenergic action prolongs APD and .beta.-adrenergic action shortens it.