常规心电图对急性前壁心肌梗死时前降支闭塞部位预测价值的临床研究

Prective value of electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery in acute anterior myocardial infarction

目的探讨急性前壁心肌梗死时的常规心电图(ECG)对前降支(LAD)闭塞部位的预测价值。方法根据冠状动脉造影的结果,以第一间隔支(S1)为标志将患者分为S1近端病变(PS)组(61例)和S1远端病变(DS)组(40例)。分别测量常规ECG12导联ST段的偏移程度及出现的频率,以计算、比较两组之间的差异及其对近、远段病变部位的预测性诊断价值。结果(1)各导联诊断LAD近端病变的敏感性和特异性分别为:aVR导联ST段抬高为43%和85%(P=0.004);aVL导联ST段抬高≥1.5mm为16%和97%(P=0.031);Ⅱ导联ST段下移≥1.0mm为39%和85%(P=0.009);Ⅲ导联ST段下移≥2.0mm为23%和98%(P=0.005);aVF导联ST段下移≥1.0mm为38%和88%(P=0.006);V5导联ST段下移为20%和86%(P=0.037);aVR导联ST段抬高同时伴V5导联ST段下移为18%和100%(P=0.005);aVR导联ST段抬高同时伴V6导联ST段下移为30%和93%(P=0.008);(2)各导联诊断LAD远端病变的敏感性和特异性分别为:Ⅲ导联ST段居于等电位线或抬高为53%和90%(P=0.000);V5导联ST段抬高≥1.5mm为50%和82%(P=0.001);(3)近、远端患者的梗死面积和心功能水平未见明显差异。结论(1)aVR导联ST段抬高同时出现V5、V6导联ST段下移;下壁导联Ⅱ、Ⅲ、aVF导联ST段明显下移(Ⅱ,aVF导联ST段下移≥1.0mm,STⅢ下移≥2.0mm)以及Ⅰ,aVL导联ST段抬高,尤其是aVL导联ST段抬高≥1.5mm均提示LAD近端病变。(2)下壁导联(尤其是Ⅲ导联)ST段居于等电位线或升高,V5导联ST段抬高≥1.5mm均提示LAD远端病变。

Objective To evaluate the predictive value of electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery （LAD） in acute anterior myocardial infarction （AMI）. Methods According to the coronary angiogram, all patients with AMI were divided into two groups： one （the PS group） was a collection of patients （n =61 ） whose occlusion sites were proximal to the first septal branch （S1 ） and the other （the DS group） was a collection of patients （n =40） whose occlusion site were distal to S1. Diagnostic sensitivity and specificity in prediction of the occlusion site in LAD were calculated based on the measurements and incidence of ST segments deviation on electrocardiogram （ECG）. Results The sensitivity and specificity for prediction of occlusion site being proximal to S1 in LAD using ECG were as follow： 43% and 85% （P =0.004） for ST elevation in lead aVR, 16% and 97% （P = 0.031 ） for ST elevation ≥ 1.5 mm in lead aVL, 39% and 85 % （ P = 0. 009） for ST depression ≥ 1.0 mm in lead Ⅱ, 23% and 98% （P =0. 005）for ST depression≥2.0 mm in lead Ⅲ, 38% and 88% （P =0. 006） for ST depression ≥ 1.0 mm in lead aVF, 20% and 86% （ P =0. 037） for ST depression in lead V5, 18% and 100% （P = 0. 005） for ST elevation in lead aVR together with ST depression in leads V5, 30% and 93% （P =0. 008） for ST elevation in lead aVR together with ST depression in leads V6. The sensitivity and specificity for diagnosis of occlusion site being distal to S1 were 53% and 90% （P = 0. 000） ST elevation or Unchanged in lead Ⅲ, 50% and 82% （ P = 0. 001 ） for ST elevation in lead V5. There were no significant difference in infarction size and left ventricle ejection fraction between the two groups. Conclusion （ 1 ） ST elevation in lead aVR together with ST depression in leads V5 and V6, obvious ST depression in the inferior leads, and ST elevation in leads Ⅰ and aVL were all indication of occlusion in LAD proximal to S1. （2） ST elevation or unchanged in inferior leads （ especially in lead Ⅲ ）, and marked ST elevation in lead V5 indicated that the occlusion site in LAD was distal to S1.