Hemodynamic Effect of Long‐term Treatment with Pindolol in Essential Hypertension with Special Reference to the Resistance and Capacitance Vessels of the Forearm

Abstract

Patients (10) with essential hypertension were studied at rest, during and after exercise following oral treatment for on an average 16 mo. with a .beta.-adrenoreceptor blocking agent, pindolol. The study was a direct continuation of an earlier, performed after 2 mo. treatment. The hypotensive effect of pindolol was highly significant after 2 as well as 16 mo. of treatment. Heart rate was similarly lowered at 2 and 16 mo., while cardiac output which was significantly lower during exercise after 2 mo., had increased to the pretreatment level after 16 mo. Peripheral vascular resistance, which was not affected after 2 mo., had decreased significantly during and after exercise in the long-term study. A comparison between the hemodynamic situations after 2 and 16 mo. thus suggests that while a decrease in cardiac output is an early mechanism in the lowering of BP, changes in systemic vascular resistance seem to be more important after long-term treatment with pindolol.