[Myocardial effects of the calcium antagonists nifedipine, nisoldipine and isradipine in coronary heart disease].

Cardiac and peripheral effects of three calcium antagonists of the dihydropyridine group were compared in three groups of ten men each with coronary heart disease (mean age 56 +/- 6 years). Dosages (by 30 minutes intravenous infusions) were: 2 mg nifedipine in group I, 0.5 mg nisoldipine in group II and 0.5 mg isradipine in group III. In this dosage peripheral effects--decrease of peripheral vascular resistance and mean aortic pressure--did not differ significantly between them. As a consequence of different negative chronotropic properties the extent of the observed reflex tachycardia was different: there was no significant heart rate increase after isradipine, an increase by 9.8% (P less than or equal to 0.001) after nifedipine and by 20.4% (P less than or equal to 0.001) after nisoldipine. Left-ventricular pressure-rise velocity as a parameter of myocardial contractility rose by 15.3% in group II (P less than or equal to 0.001) and by 13.5% in group III (p less than or equal to 0.001), but not in group I. These data show, that peripheral equipotent dosages of the three calcium antagonists can have different myocardial effects.