CEREBRAL HEMODYNAMICS IN YOUNG HYPERTENSIVE SUBJECTS AND EFFECTS OF ATENOLOL TREATMENT

The aim of this study was to evaluate changes in cerebral hemodynamics in young patients with uncomplicated hypertension before and after ef fective antihypertensive treatment with a beta-blocker drug. Changes i n mean flow velocity in the middle cerebral artery from normal conditi on to hypercapnia were evaluated by means of a transcranial Doppler in 42 hypertensive patients and 21 healthy subjects comparable for age a nd ses distribution. We obtained hypercapnia with breath-holding and e valuated cerebrovascular reactivity with the breath-holding index (BHI ). After a baseline evaluation (time 0), patients were randomly assign ed to a placebo (group 1) or atenolol (group 2) therapy. The evaluatio n was repeated after 30 (time 1) and 60 (time 2) days of treatment. Be fore treatment, hypertensive patients had significantly lower BHI valu es (0.96+/-0.1 group 1 and 0.8+/-0.3 group 2) than controls (1.69+/-0. 4) (Pi<0.0001). During treatment, mean blood pressure significantly de creased in group 2 patients. In the same group, BHI values significant ly increased with respect to the pre-treatment evaluation: 1.39+/-0.2 at time 1 and 1.44+/-0.2 at time 2 (P<0.0001). On the contrary, mean b lood pressure and BHI values remained unchanged in the placebo group. Furthermore, BHI values were significantly higher in group 2 than in g roup 1 patients at times 1 (P<0.001) and 2 (P<0.0001). These findings suggest that hypertension causes reduced capability of cerebral vessel s to adapt to functional changes. This condition, which is reversible after treatment, could be implicated in the increased susceptibility t o ischemic stroke in hypertension. (C) 1998 Published by Elsevier Scie nce B.V. All rights reserved.