Effects of carvedilol on common carotid arterial flow, peripheral hemodynamics, and hemorheologic variables in hypertension.

The effects of a beta-blocker, carvedilol, on peripheral hemodynamics and hemorheologic parameters were evaluated in 11 geriatric patients with essential hypertension [3 men and 8 women aged 62-79 years (mean, 68.6 years)]. Carvedilol was given orally after breakfast at a dose of 10 or 20 mg daily for 8 weeks. Peripheral hemodynamics, the common carotid arterial flow, and hemorheologic parameters were determined twice prior to administration and after 4 and 8 weeks of carvedilol treatment. The common carotid arterial flow was determined using the pulsed Doppler method. Peripheral hemodynamics were assessed by venous occlusion plethysmography. The hemorheologic parameters assessed include erythrocyte aggregation, erythrocyte deformability, plasma viscosity, whole-blood hematocrit, and platelet function tests. Erythrocyte aggregation was measured using an Erythrocyte Aggregometer MA-1 (Myrenne, USA), taking a high shear rate of 600 s-1 and a low shear rate of 3 s-1 as the indices. Statistical comparisons of values before and after carvedilol administration were made using the paired Student's t-test. Systolic and diastolic blood pressure were decreased by carvedilol. The common carotid arterial flow was increased, and peripheral hemodynamics were improved by carvedilol. Erythrocyte aggregation (measured at both a high and a low shear rate) and plasma viscosity were decreased, erythrocyte deformability was increased, and levels of circulating platelet aggregates were also improved by carvedilol. This improvement of hemorheologic variables may contribute to prevention of the initiation and progression of thrombosis and atherosclerosis in geriatric patients with essential hypertension.