Effects of chronic administration of selective betablockers on peripheral circulation of the lower limbs in patients with essential hypertension.

This paper summarizes the results of two studies carried out to evaluate the effects of the cardioselective betablockers atenolol, acebutolol and metoprolol on peripheral circulation of the lower limbs. The 1st study was a double dummy double blind cross over placebo controlled trial carried out for 13 weeks to evaluate the effects of acebutolol (600 mg/die) and metoprolol (300 mg/die), two cardioselective betablockers, on peripheral haemodynamics in patients suffering from mild to moderate hypertension. The 2nd study was a placebo controlled trial on the effects of atenolol (100 mg/day) on haemodynamics at the calf carried out for 8 weeks in patients suffering from essential to severe moderate hypertension, part of which aged over 65 years and affected by arteriosclerosis obliterans of the lower limbs, stage I and II according to Fontaine's classification. Calf blood flow in basal condition (R.F.) and after ischemic stimulus (P.F.) was evaluated by strain gauge plethysmography; basal (B.V.R.) and minimal (M.V.R.) vascular resistances at the calf by the ratio between M.B.P./R.F. and M.B.P./P.F. respectively, Windsor's index (W.I.) by ultrasound. Neither the patients with hypertension only nor the elderly hypertensive suffering from arteriosclerosis obliterans of the lower limbs showed changes in R.F. and P.F., in B.V.R. and M.V.R. and in W.I. after chronic treatment with cardioselective beta-blockers. Many patients--about 17% of all patients, and 40% of arteriopathics--in the two trials had cold hands and feet. These studies suggest that chronic administration of selective beta-blockers does not exert unfavourable effects on muscular blood flow at the calf in patients with hypertension with or without arteriosclerosis obliterans of the lower limbs at I and II stage.(ABSTRACT TRUNCATED AT 250 WORDS)