Significance of ST-segment Elevation or Depression in Inferior Wall Acute Myocardial Infarction to Predict the Culprit Artery

Objective The purpose of this study was to investigate the diagnostic value of electrocardiogram(ECG)ST-segment elevation or depression for infarct-related artery(IRA)in acute inferior wall acute myocardial infarction.Methods The study population included 84 patients with inferior wall acute myocardial infarction,to analyze the ST-segment elevation or depression in lead I,aVL,Ⅱ,Ⅲ,aVR,V5 and V6,comparded with coronary angiography.Results(1)The IRA of 68 patients were right coronary artery(RCA),and 16 patients were left circumflex artery(LCX).(2)ST-segment elevation in lead Ⅲ greater than leadⅡ predicted IRA was RCA(sensitivity 93%,specificity 94%,PPV 98%,NPV 79%);ST-segment elevation in lead Ⅲ lesser than leadⅡpredicted IRA wasLCX(sensitivity 81%,specificity 97%,PPV 87%,NPV 96%).(3)The ratio of ST↓V3/ST↑Ⅲ0.5 predicted IRA was RCA,(sensitivity 90%,specificity 94%,PPV98%,NPV 68%);The ratio of ST↓V3/ST↑Ⅲ1.2 predicted IRA wasLCX,(sensitivity 81%,specificity 97%,PPV 87%,NPV 97%).(4)ST-segment depression in lead aVL greater than lead I predicted IRA was RCA(sensitivity 91%,specificity 81%,PPV 95%,NPV 68%).(5)ST-segment depression in lead aVR predicted IRA was RCA(sensitivity 88%,specificity 87%,PPV 97%,NPV 64%);ST-segment elevation in lead aVR predicted IRA was LCX(sensitivity is 81%,specificity is 94%,PPV 76%,NPV 95%).(6)ST-segment elevation in lead V5 and V6 was useless to predict tne IRA.Conclusion The ECG ST-segment elevation or depression had a high positive value to predict the IRA in inferior wall acute myocardial infarction.