Factors associated with failure to identify the culprit artery by the electrocardiogram in inferior ST-elevation myocardial infarction

Background: Right and left circumflex coronary artery occlusions cause inferior myocardial infarction. To improve the targeting of diagnostic and therapeutic measures individually, factors interfering with identification of the culprit artery by the electrocardiogram (ECG) were explored. Methods: Patients with inferior preinfarction syndrome (n = 266) were included to the Danish Trial in Acute Myocardial Infarction-2 substudy. The culprit vessel was predicted by the ECG, and findings were correlated with angiography. Factors associated with false identification of the culprit artery by the ECG were examined. Results: Electrocardiogram criteria for right coronary artery occlusion to predict coronary angiography findings had sensitivity, specificity, and positive and negative predictive values of 95%, 52%, 84%, and 81%. For left circumflex coronary artery occlusion, the corresponding values were 51%, 93%, 70%, and 85%, respectively. False ECG identification of the culprit artery was independently associated with left coronary dominance (P <.001; odds ratio [OR], 22.0; 95% confidence interval [CI], 7.2-67.0), multivessel disease (P =.035; OR, 2.2; 95% CI, 1.1-4.7), and absence of proximal occlusion pattern in the ECG (P =.003; OR, 4.0; 95% CI, 1.6-9.8). Conclusions: Left coronary artery dominance, multivessel disease, and absence of ECG signs of proximal culprit lesion are associated with failure to predict the culprit artery of inferior myocardial infarction by the 12-lead ECG.