Effect of 1-(3,4, dihydroxyphenyl)-2-Isopropylaminoethanol, (Isopropylepinephrine) on the Rhythmic Property of the Human Heart.

Abstract

By the admn. of various drugs to individuals in whom it was possible to produce a consistent cardiac standstill by pressure on the carotid sinus it was shown that the only compounds effective in preventing the standstill were epinephrine and related compounds. (sympathomimetic amines). In 14 subjects in whom a cardiac standstill could be induced by carotid sinus pressure, the subcut. admn. of the isopropyl homolog of epinephrine, which has no pressor action, in doses of 0.14-0.2 mg., prevented the standstill in every instance either by restoring the activity of the sinus node or by initiating ectopic rhythmic foci. The drug also increased the ventricular rate of 5 cases of complete heart block. The blood pressure effects were predominantly a lowering of the diastolic pressures with little or no effect on the systolic pressures.