title: A comparison of the effects of beta-blockers with and without intrinsic sympathomimetic activity on hemodynamics and left ventricular function at rest and during exercise in patients with coronary artery disease.
abstract: The effects on hemodynamics and left ventricular function of propranolol and pindolol, beta-blockers without and with intrinsic sympathomimetic activity (ISA), respectively, were compared in six men with stable exertional angina at rest and during symptom-limited bicycle exercise. The study was controlled and double blinded, and the order of drug administration was randomized. The dosage of each drug (propranolol 0.15 mg/kg i.v., pindolol 0.02 mg/kg i.v.) was chosen to reduce exercise tachycardia by approximately 18%. Exercise capacity and duration were similar after each drug, and both drugs similarly reduced ST depression during exercise. At rest, propranolol significantly reduced heart rate, systolic arterial pressure, rate-pressure product, stroke volume index, cardiac index, and left ventricular ejection fraction, and increased systemic vascular resistance. In contrast, pindolol significantly reduced only the rate-pressure product and cardiac index, and to a lesser extent than propranolol. During exercise on the other hand, both drugs reduced the heart rate, arterial pressure, rate-pressure product, and cardiac index to a similar degree. Neither drug altered pulmonary artery wedge pressure, systemic vascular resistance, stroke volume index, left ventricular ejection fraction, or left ventricular end-diastolic and end-systolic volume indices. At equipotent beta-blocking dosages, ISA in pindolol reduced the effects of beta-blockade on resting hemodynamics and left ventricular function compared to propranolol, but during exercise the influence of ISA was reduced; and both pindolol and propranolol exert similar effects on hemodynamics and left ventricular function.
mesh_terms: D000328:Adult; D000787:Angina Pectoris / Q000188:drug therapy / Q000503:physiopathology*; D004311:Double-Blind Method; D005080:Exercise Test; D006352:Heart Ventricles / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000187:drug effects; D010869:Pindolol / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D011897:Random Allocation
chemical_list: D011433:Propranolol; D010869:Pindolol