Hira Ravi S, Wilson James M, Birnbaum Yochai
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
Coron Artery Dis. 2011 May;22(3):165-70. doi: 10.1097/MCA.0b013e328342c748.
Inferior ST-elevation myocardial infarction (I-STEMI) caused by proximal occlusion of the left circumflex artery (LCx) or right coronary artery (RCA) is associated with poor outcomes. We tested two new electrocardiographic (ECG) algorithms to identify proximal RCA (P-RCA), proximal LCx (P-LCx), or distal RCA or LCx in I-STEMI.
In 135 patients with I-STEMI, 115 (85.2%) had RCA occlusion [49 (36.3%) with P-RCA occlusion] and 15 (11.1%) had LCx occlusion [4 (2.9%) with P-LCx occlusion]. In the ECG algorithms, P-RCA occlusion was indicated by STE in lead III higher than lead II and no ST depression in V₁. P-LCx occlusion was indicated by STE in lead II higher than in lead III and no ST depression in aVL. One algorithm included an additional step: whether the ST-T pattern in aVL represents reciprocal changes to lead III (differences in the magnitude of ST deviation or T-wave direction were considered to indicate P-LCx occlusion).
The positive and negative predictive values of these algorithms were low (45.6 and 76.8% for P-RCA occlusion and 6.7 and 97.5% for P-LCx occlusion).
The ECG algorithms cannot reliably identify the culprit artery in I-STEMI. Right precordial leads may be needed to determine the site of lesion.
由左旋支动脉（LCx）或右冠状动脉（RCA）近端闭塞引起的下壁ST段抬高型心肌梗死（I-STEMI）与不良预后相关。我们测试了两种新的心电图（ECG）算法，以识别I-STEMI中的RCA近端（P-RCA）、LCx近端（P-LCx）或RCA或LCx远端。
在135例I-STEMI患者中，115例（85.2%）发生RCA闭塞[49例（36.3%）为P-RCA闭塞]，15例（11.1%）发生LCx闭塞[4例（2.9%）为P-LCx闭塞]。在心电图算法中，III导联ST段抬高高于II导联且V₁导联无ST段压低提示P-RCA闭塞。II导联ST段抬高高于III导联且aVL导联无ST段压低提示P-LCx闭塞。一种算法还包括一个额外步骤：aVL导联的ST-T形态是否代表III导联的镜像改变（ST段偏移幅度或T波方向的差异被认为提示P-LCx闭塞）。
这些算法的阳性和阴性预测值较低（P-RCA闭塞的阳性预测值和阴性预测值分别为45.6%和76.8%，P-LCx闭塞的阳性预测值和阴性预测值分别为6.7%和97.5%）。
心电图算法不能可靠地识别I-STEMI中的罪犯血管。可能需要右胸导联来确定病变部位。
