RT Journal Article
SR Electronic
T1 COMPARATIVE MYOCARDIAL DEPRESSANT AND ANTIARRHYTHMIC PROPERTIES OF <em>d</em>-PROPRANOLOL, <em>dl</em>-PROPRANOLOL AND QUINIDINE
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 11
OP 21
VO 158
IS 1
A1 William W. Parmley
A1 Eugene Braunwald
YR 1967
UL http://jpet.aspetjournals.org/content/158/1/11.abstract
AB The direct negative inotropic and chronotropic effects of d-propranolol, dl-propranolol and quinidine were determined in cat papillary muscle and right atrial preparations in vitro. Equivalent myocardial depression and reversion of spontaneous papillary muscle arrhythmias occurred with molar concentrations of quinidine which were 10 times as great as concentrations of d- or dl-propranolol. Infusion of equal myocardial depressant doses into rabbits revealed that quinidine produced more hypotension and arrhythmias than the other two drugs. Pretreatment with d- and dl-propranolol at three dose levels had identical effects in prolonging both the time to first arrhythmia and the time to death induced by constant infusion of ouabain. Equicardiodepressant doses of quinidine were less effective in prolonging the time to first arrhythmia, although the time to death was also prolonged. The results suggest that d-propranolol may prove to be a useful antiarrhythmic agent in selected clinical situations in which beta-adrenergic blockade is unneccessary or undesirable. © 1967 by The Williams &amp; Wilkins Company