Coronary arteriography in patients with impending and evolving myocardial infarction.

To determine whether characteristic pathologic alterations in coronary arteries are associated with impending and complicated evolving myocardial infarction, the angiographic and hemodynamic findings in 47 acute coronary patients were compared to those of 49 patients with chronic stable angina. Subtle differences in angiographic and hemodynamic alterations were found in these two groups of patients. These differences were more pronounced in patients with evolving myocardial infarction with less than--15 per cent lactate extraction. The risk of coronary arteriography was surprisingly low. Myocardial metabolic function studies demonstrating less than--15 per cent lactate extraction were considered an indication for emergency coronary arteriography in preparation for contemplated coronary bypass surgery.