Diagnostic value of electrocardiographic indices in discriminating the culprit vessel based on the coronary dominancy in inferior acute myocardial infarction.

BACKGROUND: Identifying the culprit during inferior myocardial infarction (MI) is still challenging. We determined the diagnostic effect of electrocardiographic (ECG) indices in identifying the culprit vessel of acute MI and the impact of coronary artery dominance on it.

METHODS: This cross-sectional study included patients with acute inferior MI who presented to Imam Khomeini Hospital and Tehran Heart Center and underwent primary PCI within 12 h of the onset of symptoms. A standard 12‑lead ECG was recorded and interpreted by two cardiologists. Based on the coronary angiography, the patients were divided into two groups of LCX or RCA involvement and were compared for general variables and ECG indices. The diagnostic values of the ECG indices for predicting the culprit vessel were then calculated.

RESULTS: We evaluated 411 patients with inferior STEMI (321 [77.5%] male, age 58.1 ± 11.1 years). RCA was the culprit vessel in 286 patients (69.1%) and LCX in 128 patients (30.9%). 321 patients (77.5%) were right dominant, 40 (9.7%) patients were left dominant, and 53 patients (12.8%), were codominant. Coronary dominance had minimal impact on the ECG indices regarding culprit identification even after adjustment for confounders. STE in lead III > lead II had the highest sensitivity for detecting RCA as the culprit (sensitivity: 89.2% and specificity: 57.8%). STE ≥0.1 mV in V5 or V6 leads had the highest sensitivity for detecting LCX as the culprit (sensitivity: 51.6, specificity: 93.7%).

CONCLUSION: In inferior STEMI, ECG indices can predict the culprit vessel with acceptable sensitivity and specificity independent of coronary artery dominance.