Effects of propranolol on haemodynamic changes and gas exchange at rest, in orthostasis, and on exercise in patients with arterial hypertension.
The effects of propranolol on the circulation and respiration were studied in 38 patients with essential hypertension and symptomatic renal hypertension. The hypotensive effect of propranolol was associated with decrease in the cardiac index and heart rate; the peripheral vascular resistance moderately increased, and the circulating blood volume and haematocrit value showed no essential changes. Besides, a prolongation of the pre-ejection period, the decrease of intrasystolic index, an increase in the myocardial wall-tension index, and a retardation of the elevation rate of the intraventricular pressure were observed. After propranolol medication, on transition into the vertical position the heart rate showed a less marked acceleration; the remaining haemodynamic parameters changed in orthostasis as they had done before the treatment. After propranolol medication, on exercise the systolic and mean arterial pressures, heart rate, and cardiac output exhibited lesser increases than before the treatment, whereas the circulating blood volume, diasolic pressure, and peripheral vascular resistance increased just as they had done before the treatment. At rest, during propranolol medication there appeared a certain tendency to decreased oxygen uptake; in orthostasis the degree of increase in oxygen uptake did not change by the action of propranolol. Besides, propranolol did not alter the blood-plasma levels of lactic acid and pyruvate at rest and did not essentially change the oxygen uptake during exercise. The level of lactic acid and the lactate/pyruvate quotient in plasma during exercise increased slightly less after than without propranolol.
D001810:Blood Volume; D006400:Hematocrit; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D005082:Physical Exertion; D011187:Posture; D011433:Propranolol / Q000494:pharmacology*; D012146:Rest
D011433:Propranolol; D010100:Oxygen