Correlation between electrocardiographic changes and coronary findings in patients with acute myocardial infarction and single-vessel disease

Background: Correlation of ST-segment elevation on the 12-lead electrocardiogram (ECG) with the expected affected coronary territory is established in patients with ST-elevation myocardial infarction (STEMI). In patients with non-ST-elevation myocardial infarction (NSTEMI), correlation of ischemic ECG abnormalities with the affected coronary territory has not been well-established. We sought to investigate the correlation of electrocardiographic abnormalities with the location of 1-vessel obstructive coronary artery disease (CAD) in patients with both STEMI and NSTEMI. Methods: In this retrospective study, the charts of all patients referred for coronary angiography in 2012 were reviewed. Patients with a single obstructive coronary artery plus angina-equivalent symptoms and an elevated cardiac troponin I was included. Available ECGs were interpreted by an experienced cardiologist (WSA) blinded to the result of angiography. Patients with complete bundle branch block or ventricular pacing were excluded. Ischemic ECG changes were correlated to a coronary territory based on predefined criteria. Results: Of 131 included patients (mean age 64 +/- 13 years; 74% male), 29 had STEMI and 102 had NSTEMI. Eleven of 11 patients (100%) with anterior STEMI had left anterior descending artery (LAD) obstructive CAD. Of 18 patients with inferior STEMI, 14 (78%) had right coronary artery (RCA) obstructive CAD, 3 (17%) had left circumflex artery (LCX) artery obstructive CAD, and 1 (5%) had LAD obstructive CAD. Of 102 NSTEMI patients, 53 (52%) had definite ECG ischemic abnormalities. Of 31 patients with anterior definite ECG ischemic abnormalities, 30 (97%) had LAD obstructive CAD, and 1 (3%) had RCA obstructive CAD. Of 22 patients with inferior definite ECG ischemic abnormalities, 14 (64%) had RCA obstructive CAD, 5 (23%) had LCX obstructive CAD, and 3 (14%) had LAD obstructive CAD. Conclusions: Patients with anterior STEMI had LAD obstructive CAD. Patients with inferior STEMI were highly likely to have RCA or LCX obstructive CAD. Only half of NSTEMI patients had definite ischemic ECG abnormalities. When present, anterior ischemic ECG changes in patients with single vessel CAD with NSTEMI were predictive of LAD obstructive CAD.