Haemodynamic effects of diltiazem at rest and during exercise in patients with previous myocardial infarction.
A single blind study between placebo and diltiazem (25 mg i.v. single dose) was carried out on 20 male patients with previous myocardial infarction and without exertional ischaemia. Patients, 50 +/- 6.1 (mean +/- SD) years of age, underwent a right heart catheterization with Seldinger's percutaneous approach and brachial or radial artery percutaneous catheterization. Haemodynamic variables were recorded in the supine position after catheterization in baseline conditions at rest, after a warming-up period of 6 min, before and after a first and second exercise test with stepwise increments of 25 W per 3 min. Before the second exercise test, either placebo or diltiazem (25 mg) was injected intravenously in 3 min. In comparison with placebo, diltiazem significantly reduced resting blood pressure (P less than 0.001) and systemic vascular resistance (P less than 0.001) and increased cardiac index (P less than 0.01); during exercise it also reduced the mean pulmonary arterial pressure (P less than 0.05), pulmonary wedge pressure (P less than 0.05), total pulmonary resistance (P less than 0.02), and increased the stroke volume (P less than 0.05). The present study demonstrated that intravenous diltiazem did not induce a significant rise in cardiac index but reduced the afterload and slightly reduced the preload. Diltiazem also reduced myocardial oxygen consumption and decreased blood pressure, mean right atrial pressure and slightly decreased the heart rate.
D006328:Cardiac Catheterization; D004110:Diltiazem / Q000627:therapeutic use*; D004562:Electrocardiography; D005080:Exercise Test; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy*; D005082:Physical Exertion; D010919:Placebos
D010919:Placebos; D004110:Diltiazem