Diagnostic performance of standard electrocardiogram for prediction of infarct related artery and site of coronary occlusion in unselected STEMI patients undergoing primary percutaneous coronary intervention

AIMS: To evaluate the relationship between ECG patterns and infarct related artery (IRA) in an all-comer population with ST-segment elevation myocardial infarction (STEMI) and validate current criteria for identifying IRA (right coronary artery (RCA) versus left circumflex artery (LCA)) in inferior STEMI and for diagnosing left main (LM) or left anterior descendent artery occlusion (LAD) in anterior STEMI.METHODS AND RESULTS: We retrospectively analysed ECGs at presentation and coronary angiogram in 885 consecutive patients undergoing primary percutaneous coronary intervention. Six ECG patterns were identified: anterior-STEMI (n=433; 49.0%), inferior-STEMI (i=365; 43.0%), lateral-STEMI (n=43; 5.0%), left bundle branch block (n=26; 3.0%), posterior-STEMI (n=7; 1.0%) and de Winter sign (n=7; 1.0%). The last two ECG patterns were univocally associated with LCA and proximal LAD occlusion respectively. In patients with inferior STEMI, predefined ECG algorithms showed high sensitivity(>90%) for RCA occlusion and high specificity(>90%) for LCA. The diagnostic performance was mainly determined by RCA dominance. In anterior STEMI the vectorial analysis of ST deviation in both frontal and horizontal planes could identify patients with LM/proximal LAD occlusion (adjusted-odds ratio for in-hospital mortality =2.45, 95% confidence interval: 1.31-4.56, p = 0.005) with low sensitivity (maximum 60%; using ST-depression in lead II, III, aVF + ΣSTE aVR + V1-ST depression V6≥0) and high specificity (maximum 95%; using ST-depression in inferior leads + ST-depression in V6).CONCLUSION: In STEMI undergoing primary percutaneous coronary intervention, six ECG patterns can be identified with a non-univocal relationship to the IRA. In inferior STEMI, vectorial analysis of ST deviation identifies IRA with a high appropriateness only when RCA is the dominant artery. In anterior STEMI, criteria derived from both frontal and horizontal planes identify LM/proximal LAD occlusion with high specificity but low sensitivity.