EFFECTS OF ATENOLOL AND DILTIAZEM-SR ON EXERCISE AND PRESSURE LOAD INHYPERTENSIVE PATIENTS

The effects of monotherapy with atenolol or diltiazem-SR on blood pres sure, 24 h blood pressure (BP) load and exercise capacity were tested in patients with mild to moderate (stages I and II) essential hyperten sion. After 3-week single blind placebo therapy patients with sitting diastolic blood pressure (SDBP) of 94-114 mmHg were randomized to aten olol 50 mg/day (62 patients) or diltiazem-SR 90 mg b.i.d. (60 patients ) in a double-blind parallel study. Depending on SDBP response, the do se was increased to 100 mg/day for atenolol and 180 mg b.i.d. for dilt iazem-SR. Twenty-four-hour ambulatory blood pressure measurements and exercise tolerance test by the Bruce protocol were done at the end of placebo and active treatment. Compared with placebo, both atenolol and diltiazem-SR significantly decreased heart rate (HR), sitting systoli c blood pressure (SSBP), SDBP, ambulatory BP, BP load for waking and s leeping hours, area under the BP curve, rate-pressure product (p<0.001 ), and exercise time (NS). Atenolol exerted a greater effect on ambula tory BP, HR, rate-pressure product, waking diastolic BP load, and area under the 24-h BP curve. The drugs were well tolerated and caused no serious side effects necessitating discontinuation of treatment. These endings,os indicate that (1) monotherapy for hypertension with atenol ol or diltiazem-SR is effective and well tolerated, (2) it decreases t he 24-h BP load (3) it does not interfere with exercise capacity.