体表心电图错误判断或无法判断梗死相关动脉的原因分析

目的 将体表心电图(ECG)预测的梗死相关动脉(IRA)与冠状动脉造影结果 进行对比分析,以了解判断错误的原因和可能机制.方法 搜集2004年10月至2009年7月就诊的急性ST段抬高心肌梗死(STEMI)患者,入选发病时间≤12 h并且术前有≥2份18导联ECG,排除既往有陈旧性心肌梗死、冠状动脉旁路移植术后、起搏器置入术后或ECG显示有左束支传导阻滞的患者.所有患者入院后都在2 h内施行了急诊冠状动脉造影.采用最常用的ECG标准判断IRA,并与冠状动脉造影结果 进行对比分析.结果 入选STEMI患者1024例,其中854例能够通过ECG判断IRA,96例判断错误,74例无法判断.判断错误和无法判断的170例患者中有76例(44.7%)IRA为左回旋支,66例(38.8%)为右冠状动脉,20例(11.8%)为左前降支,7例(4.1%)为中间支,1例(0.6%)为左主干;27例(15.9%)合并双支病变,47例(27.6%)合并三支病变;8例(4.7%)合并早期复极综合征;6例(3.5%)患者冠状动脉造影提示小分支闭塞.结论 侧支循环影响ECG对IRA的判断.ECG无法判断IRA时最常见于左回旋支病变.解剖变异、早期复极综合征或小分支闭塞也会影响IRA的判断.

Reasons for failed electrocardiographic identification of the infarct-related artery in patients with ST-elevation acute myocardial infarction

Objective The infarct-related artery (IRA) could not always be identified by electrocardiogram (ECG). In the present study, we attempted to explore the reason for failed IRA identification by ECG based on the comparison between ECG records and coronary angiographic findings. Methods All 18-lead ECG records were compared with respective angiographic findings in 1024 consecutive patients with ST elevation myocardial infarction (STEMI) between October 2004 and July 2009.More than two continous18-1ead ECG records were performed within 12 hours of the symptom onset in all patients. Patients with previous myocardial infarction, coronary artery bypass surgery, pacemaker implantation or ECG evidence of left bundle branch block and angiography was performed more than 12 hours time from symptom onset were excluded. Results Of all 1024 patients enrolled, the IRA were correctly identified in 854 cases and identified wrong in 96 cases and could not be identified in 74 cases by ECG. Of the failed identification in these 170 cases, IRA was left circumflex coronary artery in 76 (44.7% )cases,right coronary artery in 66 (38.8% ) cases, left anterior descending branch in 20 ( 11.8% ) cases, ramus medianus branch in 7 (4.1% ) cases, and left main in 1 (0.6% ) case. Double-vessel and triple-vessel diseases were recorded in 27( 15.9% ) patients and 47(27.6% ) patients respectively. Early repolarization syndrome occurred in 8 (4.7% ) patients, and dextrocardia in 1 patient (0.6% ). Angiographic study showed acute occlusion of a small branch in 6 (3.5%) patients. Conclusion Coronary collateral vessel can mislead judgments of the IRA by ECG. When the IRA can not be determined by ECG, left circumflex coronary artery is most likely to be the culprit vessel Occasionally, early repolarization syndrome and anatomic variation of the coronary artery or heart and a small branch occlusion could be causes of misjudgments of IRA by ECG.