The study population consisted of 11 patients (eight male, three female; mean age, 43.8 years) with mild to moderate essential hypertension in World Health Organization (WHO) stages 1 or 2. Patients showing clinical or instrumental evidence of ischemic heart disease, heart failure, or other cardiac disease were excluded. No patient had ever taken any kind of antihypertensive treatment.
Baseline blood pressure value was defined as the average of the lowest measurement from each of three different visits. Blood pressure and heart rate were always measured with the patients in the supine position for at least 5 min, in the late morning after the patients had taken drug from 3 to 4 h. The treatment with prazosin, as monotherapy, was started at a dosage of 1 mg twice a day and then progressively increased up to a maximum of 7.5 mg twice a day, in case hypertension was not controlled. Therapy was taken for at least six months in which blood pressure had to be normalized or the maximum dosage of the drug was reached. Mean follow-up time was 11.7 months (range, 7 to 14 months). The values reported as the treatment response represent the average of the two lowest measurements from two visits performed one or two weeks apart. All the patients underwent exercise stress testing, M-mode echocardiography under B-mode drive, and “”Tc radionuclide ventriculography at equilibrium, both at entry and at the end of the study.