Premium
Nonselective β‐receptor stimulation and blockade and left ventricular function
Author(s) -
Leenen Frans H H,
Smith Donna L,
DeLeve Laurie
Publication year - 1983
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1983.217
Subject(s) - blockade , stimulation , ventricular function , medicine , cardiology , receptor
The effects of increasing doses of intravenous isoproterenol on left ventricular (LV) size and function were assessed before and after oral propranolol (80 mg). Eleven normal subjects were studied by M‐mode echocardiography. The isoproterenol dose was increased until heart rate had risen by 25 to 30 b.p.m. LV end‐diastolic (LVED) dimension (46.6 ± 1.3 mm) was increased by isoproterenol (to 48.8 ± 1.5 mm) and decreased by propranolol (to 45 ± 1 mm). LV end‐systolic dimension was decreased by isoproterenol and increased by propranolol. Isoproterenol increased LVED dimension despite the opposing effect of the tachycardia, whereas propranolol decreased LVED dimension despite its negative inotropic and chronotropic effects. These results suggest that nonselective β‐receptor stimulation or blockade can affect cardiac output through direct cardiac actions and by influencing venous return. Clinical Pharmacology and Therapeutics (1983) 34, 570–575; doi: 10.1038/clpt.1983.217