Double-Blind-Comparison of the Effects of Nifedipine and Isosorbide-5-mononitrate on the Circulatory Response to Exercise, Exercise Tolerance, and ST-Segment Depression in Patients with Ischemic Heart Disease

Abstract

The hemodynamic profiles of calcium antogonists and nitrates are different. Calcium antagonists and, in particular, nifedipine reduce systemic vascular resistance and blood pressure and tend to raise pulse rate and cardiac output. However, even preload, in terms of left ventricular filling pressures, is lowered [4–7], apparently due to a consequent blood volume shift from the intrathoracic to the extrathoracic compartments of the low pressure system. Nitrates do not consistently lower systemic vascular restistance, but they reduce right and left ventricular filling pressures substantially and tend to lower cardiac output by this mechanism [3]. Nitrates have been used for the treatment of angina for more than 100 years and are still one of the most widely used drugs in the management of ischemic heart disease. Calcium antagonists have been increasingly used since their introduction in clinical cardiology some 10 years ago.