[Proceedings: The effect of beta receptor treatment with pindolol on the plasma renin activity and the left-ventricular dynamics in essential hypertension].

In 5 volunteers with essential hypertension (age between 32 and 48 years) plasma renin activity (PRA) was determined and right heart catheterization and femoral artery pressure measurements were carried out at rest and during isometric exercise by handgrip. Both investigations were repeated 88 to 98 days after continuous treatment with oral pindolol in increasing doses, the highest dose in all patients amounting to 45 mg/day. Following pindolol therapy arterial systolic cuff pressure decreased from 163 +/- 12 (1 SD) to 148 +/- 14 mm Hg (p less than 0,005). Diastolic cuff pressure decreased slightly but not significantly from 109 +/- 13 to 106 +/- 9 mm Hg. PRA varied in an inconsistent manner. Pulmonary capillary pressure (PCP), femoral artery mean pressure (FAM), cardiac output (CO) and systemic vascular resistance did not change significantly during treatment with pindolol. Stressing of the left ventricle by handgrip prior to and following pindolol elicited similar changes of heart rate, FAM, PCP, CO and stroke work. It is concluded (1) that pindolol produces only a small decrease in systolic cuff pressure, (2) that there is no correlation between changes in cuff pressure and PRA, and (3) that long-term treatment with pindolol is not accompanied by impairment of left ventricular function either at rest or during isometric exercise.