Differentiating the Infarct-Related Artery on Initial Electrocardiogram in Single or Multi-Vessel Disease in Acute Inferior Myocardial Infarction and Evaluating Involvement of Vessels Using Correspondence Analysis

Abstract

Initial electrocardiography changes were compared prospectively with the findings of coronary angiography to predict the infarct-related artery (IRA) in cases of single- and multi-vessel disease and to demonstrate the relationship between other coexisting coronary involvements and IRA in patients who presented with acute inferior myocardial infarction (AMI). ST elevations or depressions of at least 1 mm (0.1 mV) were evaluated in the leads I, aVL, and V₁-V₆. Of the 160 patients hospitalized due to inferior AMI, 153 (96%) underwent coronary angiography using standard methods. The angiograms were screened for stenotic lesions using quantitative coronary angiography to confirm significance, which was considered >50% vessel lumen diameter reduction. Among single-vessel involvements, the IRA was either the circumflex artery (Cx) or right coronary artery (RCA). In conditions in which IRA was detected as either Cx or RCA, 1-, 2-, and 3-vessel involvements were also detected. Correspondence analysis was performed to show the vessel involvements accompanying IRA. Compared with patients with IRA as RCA, the presence of ST depressions in the leads V₁ or V₂ and aVL were more frequently seen in patients with IRA as Cx (p=0.000, p=0.015, respectively). Among all vessel involvements in which IRA was either Cx or RCA, a ST-segment depression in leads V₁ or V₂ (p=0.000) and aVL (p=0.000) and a ST-segment elevation in lead I (p=0.005) were considered to be significant for Cx, and a ST-segment depression in lead I for RCA involvement (p=0.010). According to correspondence analysis, the most frequent single-vessel involvement seen in inferior AMI was RCA; when IRA was RCA, a multi-vessel involvement included RCA and Cx; and when IRA was Cx, a single-vessel involvement included the left anterior descending (LAD) artery most frequently, and RCA+LAD less frequently (p=0.000). In inferior AMI, RCA was the most common IRA; however, the possibility of multi-vessel disease is increased when Cx is found to be the IRA. In patients presenting with inferior AMI, the presence of ST-depression in the leads aVL and V_1-2 is a sensitive finding that indicates Cx stenosis rather than RCA stenosis and is not affected by coexisting other coronary artery involvements.