DIFFERENT CARDIODEPRESSANT POTENCY OF VARIOUS CALCIUM-ANTAGONISTS IN HUMAN MYOCARDIUM

Calcium antagonists play an important role in the therapy of systemic hypertension1 and coronary artery disease.2 In heart failure, it has been reported that calcium antagonists produce beneficial hemodynamic effects by reducing afterload.3 These compounds also produce negative inotropism, which can be of potential benefit in coronary artery disease by reducing energy expenditure of the heart or in hypercontractile states, such as some forms of hypertrophic cardiomyopathy. The therapeutic potential is often limited by their negative inotropic effects, which, in addition to their vasodilatory properties, can lead to severe hypotension. Direct negative inotropic effects of calcium antagonists have been studied in various laboratory animals and species differences were observed.4 Hitherto, data on the human heart have not been available. This study was performed to compare the negative inotropic effects of 1,4 dihydropyridines (nifedipine, nitrendipine), diltiazem and verapamil on diseased human myocardium. Isradipine, a new 1,4 dihydropyridine with supposedly minor negative inotropic actions, was also studied. © 1990.