急性下壁心肌梗死ST段改变与相关冠状动脉阻塞的关系

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

目的探讨急性下壁心肌梗死ST段改变与相关冠状动脉阻塞的关系。方法收集53例急性下壁心肌梗死患者,均在发病6h内做心电图,3周内做冠状动脉造影术,并对比分析心电图ST段改变与冠状动脉造影资料。结果急性心肌梗死患者中,单支病变18例,双支病变22例,多支病变13例;右冠状动脉狭窄38例(71.7%),左回旋支狭窄15例(28.3%)。ST段抬高Ⅲ>Ⅱ,ST段压低aVL>Ⅰ,诊断右冠状动脉阻塞的敏感性为92.1%,特异性为73.3%;反之诊断左回旋支阻塞的敏感性为73.3%,特异性为73.7%。V3导联ST段压低与Ⅲ导联ST段抬高比值>1.2,诊断左回旋支阻塞的敏感性为100.0%,特异性为86.8%。aVR导联ST段压低<1mm,诊断右冠状动脉阻塞的敏感性为97.4%,特异性为86.7%;aVR导联ST段压低≥1mm,诊断左回旋支阻塞的敏感性为80.0%,特异性为94.7%。结论急性下壁心肌梗死ST段抬高Ⅲ>Ⅱ,ST段压低aVL>Ⅰ,提示右冠状动脉阻塞;反之提示左回旋支阻塞。V3导联ST段压低与Ⅲ导联ST段抬高比值>1.2,aVR导联ST段压低,提示左回旋支阻塞。故急性下壁心肌梗死患者心电图ST段改变可作为区分右冠状动脉和左回旋支阻塞的可靠指标。

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 anglographic 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 ratio 〉 1.2, 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 ≥ 1 mm in aVR lead, identified occlusion of LCX （sensitivity 80%, specificity 94.7% ）. Conclusion In patients of acute inferior myocardial infarction, elevate of ST - segment Ⅲ 〉 Ⅱ , ST - segment depression aVL 〉 Ⅰ, indicated occlusion of RCA, conversely, indicated occlusion of LCX, ST - segment depression in lead V3/ST - segment elevation in lead Ⅲ ratio 〉 1.2, 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.