title: Comparative haemodynamic dose-response effects of intravenous propranolol and pindolol in patients with coronary heart disease.
abstract: To determine whether the depression of left ventricular pumping activity associated with beta-blockade alone could be offset by a substantial degree of partial agonist activity, the haemodynamic dose-response effects of intravenous propranolol and pindolol were compared in a randomised between-group saline controlled study in twenty patients with angiographically proven coronary artery disease. The intravenous doses of propranolol (2-16 mg) and pindolol (0.2-1.6 mg) used were selected on the basis of published reports of equivalence in terms of exercise blockade of chronotropic beta-adrenoceptors. Following four intravenous boluses of each drug, administered according to a cumulative log-dosage schedule, there was a log-linear increase in the plasma concentrations of each drug. The range of plasma concentrations achieved were those which have been shown to be associated with substantial attenuation of sympathetic stimulation of cardiac beta-adrenoceptors. At rest propranolol resulted in dose-related linear reductions in heart rate and cardiac output and linear increases in left heart filling pressure and systemic vascular resistance compared with saline-controlled measurements. The only statistically significant change at rest after pindolol was a small increase in the left heart filling pressure. The calculated systemic vascular resistance was increased after propranolol but unchanged after pindolol. During supine bicycle exercise the systolic blood pressure increased less after propranolol than after saline or pindolol. The increments in all other measured haemodynamic variables during exercise were equally influenced by the two drugs.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000787:Angina Pectoris / Q000209:etiology; D003327:Coronary Disease / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D010869:Pindolol / Q000627:therapeutic use*; D011433:Propranolol / Q000627:therapeutic use*
chemical_list: D011433:Propranolol; D010869:Pindolol