Angiographic and clinical characteristics of patients with unstable angina showing an ECG pattern indicating critical narrowing of the proximal LAD coronary artery.

One hundred eighty of 1260 patients consecutively admitted to the hospital because of unstable angina pectoris had the typical ST-T segment changes suggestive of a critical stenosis in the proximal LAD. In 108 patients the ECG abnormalities were present at the time of admission. In the remaining 72 patients they developed shortly thereafter. The difference between these two groups was a longer duration of anginal complaints in the former (mean 2.3 days). Results of coronary angiography, performed a mean of 4.6 days after the last attack of chest pain, showed 50% or more narrowing in the proximal LAD in all patients. Thirty-three patients had complete occlusion of the LAD and 75 had collateral circulation to the LAD. Results of left ventricular angiography showed abnormal systolic left ventricular wall motion in 137 patients and normal systolic motion in the remaining 43 patients. The difference between these two groups was a shorter mean time interval between the last attack of chest pain and angiography in the former group (p less than 0.001). Twenty-four patients had only abnormal diastolic wall motion. Twenty-one patients had a small increase in the creatine kinase level at the time of admission. Fifteen patients (nine before and six during early revascularization) had an anterior wall myocardial infarction in the hospital; these patients had a patent but severely narrowed LAD and a low incidence of collateral circulation to the LAD.(ABSTRACT TRUNCATED AT 250 WORDS)