Myocardial Blood Flow following Experimental Coronary Occlusion

To determine the effects of diltiazem, a new calcium antagonist, on myocardial ischemia, two experiments were performed. The results showed 1) the intravenous bolus injection of large doses of diltiazem reduced ST segment elevation in open-chest dogs with acute coronary occlusion. The regional myocardial blood flow in the control area, as well as moderately and mildly ischemic areas increased significantly after diltiazem. However, the myocardial Mood flow of the severely ischemic area did not increase; 2) the continuous infusion of small doses of diltiazem after coronary occlusion for 24 hours caused a significant increase of myocardial blood flow to the circumscribed region at the ischemic center, and induced a tendency to a slight reduction in size of the myocardial infarction.