Propranolol on Coronary Vascular Resistance

Propranolol on Coronary Vascular Resistance

Effects of beta-receptor blockade on the systemic and coronary hemodynamic response to an increasing ventricular rate in the unanesthetized dog.

Phasic coronary and aortic blood flow and arterial pressure were measured as heart rates were increased by ventricular pacing from 120 to 270 beats/min in unanesthetized dogs before and after beta-receptor blockade with intravenous propranolol. Before beta-receptor blockade, coronary flow progressively increased and coronary vascular resistance decreased with increasing heart rates. Aortic bloo...

High dose propranolol in the treatment of angina pectoris: relationship of dose to blood levels and hemodynamic consequences.

Propranolol blood levels and the effect of these levels on hemodynamic parameters were evaluated in 25 patients with coronary artery disease undergoing cardiac catheterization and coronary angiography. Fifteen patients were receiving high doses of propranolol (320--1920 mg/day) while ten patients were receiving conventional doses (80--240 mg/day). The high dose propranolol group had significant...

Coronary Vasoconstriction in Dogs

We determined whether a 3-minute period of intense cardiac sympathetic stimulation, which is known to release neuropeptide Y (NPY), elicits a sustained poststimulatory coronary vasoconstriction in anesthetized dogs that had received propranolol. We also periodically measured the cardiac chronotropic responses to test vagal stimulations; these responses served as an index of the neuronal release...

The Myocardial Depressant Effect of Beta-Receptor Blocking Agents COMPARATIVE STUDY OF <//-PROPRANOLOL, d-PROPRANOLOL. AND PRACTOLOL IN AWAKE DOGS WITH AND WITHOUT ACUTE MYOCARDIAL INFARCTION

d/-Propranolol, d-propranolol, and practolol were administered in increasing doses to conscious dogs before and after acute coronary artery occlusion. cM-Propranolol and practolol caused dose-dependent decreases in cardiac output, stroke volume, stroke work, and maximum rate of left ventricular pressure rise before and after coronary artery occlusion. These parameters were reduced 25-40% after ...