[Effects of the association of Ca-antagonists with nitroderivatives or betablocking drugs in effort angina pectoris (author's transl)].

The effects of the association of calcium antagonists (CAI) with a nitroderivate and a betablocker were studied by means of exercise tests in 8 patients with stable effort angina pectoris. According the statistical model of a latin square 4 x 4, the first 4 patients were tested with the following treatments: placebo, oral; nifedipine (N) 10 mg, oral; N + isosorbide dinitrate (ISDN) 10 mg oral; N + propranolol (Pr) 40 mg, oral. In the second square verapamil 80 mg oral represented the CAI treatment. Compared to placebo, all the treatments produced a significant increase of exercise duration and total work performed before angina. In both the squares the improvement observed after CAI + ISDN was significantly higher than after administration of CAI alone. In both the squares the association of CAI + Pr determined a little, non significant improvement of exercise duration in respect to CAI alone. EKG positivity was delayed by Pr more than angina appearance: hpwever, also this effect was not significant when compared with administration of CAI alone. By the analysis of the changes of heart rate, maximal arterial pressure, ejection time and triple product at the same level of work, a relevant inhibition of myocardial contractility with the adopted doses of CAI can be excluded; the effect of these drugs seems to be due mainly to a decrease of arterial pressure, and, when associated to ISDN, to decreases of arterial pressure and ejection time.