Atenolol once daily in angina.

: Both atenolol 50 mg daily (A-50) and atenolol 100 mg daily (A-100) significantly reduced the angina attacks per week compared with placebo (p less than 0.05). Nitroglycerine consumption was less on A-50 (p less than 0.05) and on A-100 (p less than 0.025) than on placebo. There was no difference between the atenolol dosages in these respects. In comparison with placebo, atenolol gave a significant increase in total work performed until the appearance of 1 mm ST segment depression in bicycle exercise tests made between 3--4 p.m. (A-50: p less than 0.05; A-100: p less than 0.0017). The rate-pressure products (systolic BP X heart rate X 10(-2) at 6' at 30 W) was 163.5 +/- 12.5 (S.E.) on placebo. It diminished to 129.8 +/- 7.9 on A-50 (p less than 0.01) and to 113.9 +/- 6.6 on A-100 (p less than 0.001). The effect of A-100 on the rate-pressure product was stronger than that of A-50 (p less than 0.05). Relative heart volume did not change on A-50 compared with placebo but A-100 resulted in a slight enlargement of 22 ml/m2 BSA when compared to placebo (p less than 0.01). Side effects were minimal.