Hemodynamic Effects of Acute β-Adrenergic Blockage with Atenolol

Abstract

8 healthy volunteers (age 25^±4 years) received in randomized sequence 50, 100, 200, 400, and 600 mg Atenolol orally and 50 mg Atenolol intravenously during 5 minutes under continuous ECG monitoring. On 3 consecutive days prior to the first application of Atenolol the volunteers were exercised on the treadmill under continuous measurement of the blood-pressure until a heart rate of 150 min was achieved. This individually determined load was used on the treadmill 3 h after oral and 1 hour after i.v.-application of Atenolol. Systolic and diastolic blood pressure and heart rate was measured at rest and after 1.5 min and 3 min of exercise. The results are expressed as difference between rest (=0) and exercise in blood pressure (Δs=systolic_{2 1}Δd=diastolic RR in mm Hg) and heart rate (HR in min).