Relationship between ST-segment Change of Acute Inferior Myocardial Infarction and Coronary Occlusion

Objective To study Relationship between ST-segment change of acute inferior myocardial infarction(AMI) and coronary occlusion.Methods We analyzed 53 inferior AMI patients (mean age59.1±13.9,38 males),The electrocardiogram (ECG) recorded within 6h of the onset of symptoms that had the most prominent ST-segment changes was analyzed and coronary angiography (CAG) within 3 weeks of the onset of symptoms.We analyzed electrocardiographic and angiographic findings.Results The patients whom were 18 cases of single-vessel disease,22cases of double-vessel diseases and 13 cases of multi-vessel diseases,right coronary artery (RCA) stenosis 38 cases (71.7%),left circumflex coronary artery (LCX) stenosis 15 cases(28.3%).ST-segment elevation in lead Ⅲ was higher than in lead Ⅱ,ST- segment depression in lead aVL exceeded that in lead I with a sensitivity of 92.1% and a specificity of 73.3% for diagnosing RCA as the culprit vessel and vice verse when the LCX as the culprit vessel(sensitivity 73.3%,specific -ity 73.7%).ST-segment depression in lead V3 / ST-segment elevation in lead Ⅲ ratio1.2,identif -ied occlusion of LCX (sensitivity 100%,specificity 86.8%).ST- segment depression 1mm in aVR lead,identified occlusion of RCA (sensitivity 97.4%,specificity 86.7%).ST-segment depression ≥1mm in aVR lead,identified occlusion of LCX(sensitivity80%,specificity 94.7%).Conclusion In patients of acute inferior myocardial infarction,elevate of ST-segment ⅢⅡ,ST -segment depression aVLI,indicated occlusion of RCA,conversely,indicated occlusion of LCX,ST-segment depression in lead V3 / ST-segment elevation in lead Ⅲ ratio1.2,ST-segment depres -sion in aVR lead,indicated occlusion of LCX.Therefore ST-segment changes can discriminate occlusion of RCA or occlusion of LCX that as the dependable index among inferior AMI patients.