Verapamil in chronic stable angina. A controlled study with computerized multistage treadmill exercise.

The efficacy of verapamil (360 mg daily) in the treatment of patients with chronic stable angina pectoris was compared with placebo. 28 patients were studied in a placebo-controlled double-blind crossover trial of 2 weeks each and afterwards on long-term verapamil. Exercise tests were performed at the end f the placebo period, and after 2 weeks and 4 weeks on verapamil. On placebo, angina developed in all 28 patients during treadmill tests; the mean exercise time was 6.6 min (SEM +/- 0.5 min). The mean exercise time increased to 9.2 (+/- 0.8) min at 2 weeks, and 11.2 (+/- 0.8) min at 4 weeks on verapamil. In 15 and 20 patients out of the 28 angina did not develop during treadmill exercise at 2 and 4 weeks respectively. Trinitrin consumption also decreased. There was a significant improvement in ST-segment changes. Constipation (in 7 patients) and reversible PR-interval prolongation (in 2 patients) were the only side effects. No patient had clinical signs of heart-failure. Thus verapamil (360 mg daily) may be useful in the management of chronic stable angina.