Exercise stress test in young hypertensive patients. Response to vasodilators (prazosin) vs. beta-blocker (atenolol) agents.

Dynamic response of arterial blood pressure during exercise has been studied in 40 normotensive young subjects and 20 mild hypertensive young patients (20-40 years of age). Hypertensive patients were treated with atenolol (beta blocker) and prazosin (vasodilator). Both groups underwent maximal exercise stress test. A double-blind nonrandomized study was practiced in hypertensive patients with placebo, prazosin (3 mg/12 h), and atenolol (100 mg/24 h). Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and exercise duration (ED) were analyzed. All parameters remained stable in both groups. The hypertensive patients showed an increase in maximum SBP more than 230 mmHg during the placebo phase. This same group showed a significant increase in HR at rest two hours after administration of prazosin. Atenolol produced a significant reduction in HR both during rest and exercise. Both drugs produced a significant decrease in SBP and DBP (at rest and exercise). We conclude that exercise test is a noninvasive procedure that could distinguish mild arterial hypertension. The dynamic changes of arterial blood pressure can be controlled with prazosin (3 mg/12 h) or 1 daily intake of 100 mg atenolol.