Effects of nicardipine or nifedipine added to propranolol in patients with coronary artery disease

Abstract

To assess the added effects of nicardipine and beta-blockers on the left ventricular (LV) function, 2.5 mg of i.v. nicardipine was given to 9 patients with coronary artery disease, pretreated with propranolol (0.1 mg/kg, i.v.). The changes in LV function observed after nicardipine were compared with those induced by nifedipine (20-30 mg sublingually), in 8 comparable patients also pretreated with propranolol. Nicardipine normalized the cardiac output and the rate of LV relaxation, both depressed by propranolol, without changes in LV filling pressure. After nicardipine, end-systolic volume (52 to 42 ml/m2; P less than 0.01) and ejection fraction (59 +/- 8 to 66 +/- 9%; P less than 0.01) improved; the mean systolic and diastolic wall stresses decreased respectively by 19% (P less than 0.01) and 21% (P less than 0.01) whereas the maximal LV pressure/volume ratio (Emax), an index of LV inotropic state, was unchanged (+4%; NS). Further, although nicardipine and nifedipine produced identical changes in LV systolic pressure (-25 vs -26 mmHg; NS nicardipine vs nifedipine) and in heart rate, the changes in end-systolic volume (-9 +/- 4 vs -3 +/- 9 ml/m2; P less than 0.005), in Emax (+0.14 +/- 0.31 vs -0.20 +/- 0.22 mmHg/ml/m2; P less than 0.025) and in ejection fraction (+7 +/- 4 vs +2 +/- 4%; P less than 0.025) were significantly greater after nicardipine than after nifedipine. In conclusion, nicardipine administered after propranolol improves LV pump function and has no negative inotropic effects as indicated by the lack of dP/dt Max and Emax changes. These additive effects of nicardipine after propranolol were greater than those of nifedipine administered at an equipotent vasodilator dosage.