Catechol Amine Induced Cardiac Arrhythmias during Chloroform Inhalation: The Role of Epinephrine Tachyphylaxis

　Injections of 1.57±0.27μg/kg of epinephrine induced ventricular arrhythmias during inhalation of one per cent chloroform. Dogs pretreated with infusion or intermittent injection of epinephrine were protected from ventricular irregularities were given from 10〜20μg/kg of epinephrine during chloroform anesthesia. A tachyphylaxis to ventricular arrhythmias developed within 15 minutes following administration of an infusion of 1μg/kg/min of epinephrine during chloroform anesthesia.