[Direct myocardial anti-ischemic effect of diltiazem in the human].

In a randomized double blind placebo-controlled study in 20 patients the influence of the calcium antagonist diltiazem (1.0 mg administered intracoronarily, distal from the stenosis) on the severity of myocardial ischemia during therapeutic coronary occlusion (transluminal coronary angioplasty) of the left anterior descending coronary artery was investigated. The severity and time of onset of ischemic ST and T wave changes as well as anginal pain were significantly reduced 3 and 8 minutes after diltiazem, whereas there was no definite change in the controls. Heart rate and blood pressure were not influenced by diltiazem or placebo. The results indicate a direct antiischemic effect of diltiazem on myocardial cells. The findings can neither be explained by an influence on cardiac afterload nor by coronary vessel reactions, nor a reduction of myocardial contractility. The findings do not permit conclusions in terms of the duration of this direct antiischemic mode of action.