[Cross-over double-blind study of verapamil versus diltiazem in effort myocardial ischemia]

There is a number of factors in favor of a different effect between the two main calcium-blockers causing bradycardia. The effects of 3 doses of verapamil 120 mg and 3 doses of diltiazem 60 mg, were compared in a double-blind study with cross-over, in 12 patients with coronary insufficiency diagnosed by coronary angiography. Four stress tests were performed in each patient, two with placebo before each treatment period and two after treatment, according to the Bruce protocol, using a computerized ECG reading system. As compared with the placebo, the two products decrease the myocardial oxygen needs, increase the duration of the stress and improve the baseline offset of the ST segment. The ischemia, demonstrated by the baseline offset of the ST segment, appears significantly less with verapamil than with diltiazem.