Scopolamine on Heart Rates in Man

Abstract

Departments of Anesthesiology and Statistics, University of Florida MethodsA small dose ( 0.1 or 0.2 mg.) of scopolamine injected intravenously slows heart rate in resting, conscious subjects. 1 • 3 This mild bradycardia can be converted into a tachycardia by additional scopolamine given intravenously. Within an hour, however, heart rate once again slows, a phenomenon we have called "secondary bradycardia."3The present study was undertaken to define the maximal dose of scopolamine that would decrease heart rate and the minimal dose that would increase heart rate. We gave 0.2 mg. of atropine, intravenously, 180 minutes after the scopolamine. In subjects effectively pretreated with a belladonna drug, this dose of atropine will increase heart rate, 3 whereas it will decrease, or at least fail to increase, rate when no effect from a previous belladonna injection persists.Six normal Caucasian volunteers ( 4 women, 2 men), between 21 and 30 years of age, participated in the study. The subjects fasted for 4 hours then rested for one hour in the supine position, during which period a slow intravenous glucose ( 5 per cent) infusion, which made rapid intravenous injection of drugs possible, was started. Scopolamine was then given and heart This study was supported in part by N a tiona! Institutes of Health Grants HE07129 and GM16239.Received for publication June 12, 1968. Accepted for publication Dec. 13, 1968. 395

Cardiovascular Effects of Etomidate Used for Induction and in Combination with Fentanyl‐Pancuronium for Maintenance of Anaesthesia in Patients with Valvular Heart Disease

“…Ifsuch movementsoccur, they could present a problem for cardiovascular measurements. Scopolamine was chosen for its lack of chronotropic effect (GRAVENSTEIN & THORNBY 1969). Our findings of cardiovascular stability during induction with etomidate 0.3 mgkg-' are in agreement with the results obtained by KETTLER et al (1974).…”

An anti‐nicotinic cognitive challenge model using mecamylamine in comparison with the anti‐muscarinic cognitive challenge using scopolamine

“…As previously described, scopolamine marginally (on average four beats per minute) reduced the heart rate when compared to placebo. Decrease of heart rate after acute scopolamine administration has been described previously after a paradoxical short increase in the heart rate .…”

Cardiovascular Haemodynamics During Fluroxene Anaesthesia in Patients with Aortic Valvular Disease

“…This decrease was compensated for by a highly significant increase in pulse frequency from a mean of 71 to 97 from the second to the third measurements. Scopolamine was chosen for its lack of chronotropic effect ( GRAVENSTEIN & THORNBY 1969), which makes it preferable to atropine when tachycardia should be avoided, as in patients with cardiac valvular disease where digitalis is discontinued at least 24 h prior to surgery. Striking is the significant decrease in Table 2 Cardiovascular parameters in nine patients anaesthetised using fluroxene.…”