Effect of beta-adrenergic blockade on blood pressure variation in patients with moderate hypertension.

The effect of beta-adrenergic blockade on blood pressure variation was studied in ten patients with moderate hypertension. Supine systolic and diastolic blood pressures were measured every 5 min during six hours sessions, using an ultrasonic method. Systolic and diastolic variation in each six hour session was defined as the standard deviation of the mean of systolic and diastolic readings made in that period. After 3 weeks of single-blind placebo, a 12 week double-blind randomized crossover study was initiated with placebo (6 weeks) and atenolol (100 mg b.i.d. for 3 weeks and 200 mg b.i.d. for 3 weeks). Systolic and diastolic blood pressure and heart rate decreased significantly (p less than 0.01) during atenolol treatment. Diastolic variation did not change significantly, whereas systolic variation decreased slightly but significantly (p less than 0.05) when expressed in absolute values, but not when expressed as a percentage of systolic blood pressure. It is concluded that beta-adrenergic blockade decreases blood pressure and heart rate without causing significant changes in spontaneous systolic or diastolic variation.