Sgarbossa E B, Pinski S L, Barbagelata A, Underwood D A, Gates K B, Topol E J, Califf R M, Wagner G S
Cleveland Clinic Foundation, Department of Cardiology, OH 44195, USA.
N Engl J Med. 1996 Feb 22;334(8):481-7. doi: 10.1056/NEJM199602223340801.
The presence of left bundle-branch block on the electrocardiogram may conceal the changes of acute myocardial infarction, which can delay both its recognition and treatment. We tested electrocardiographic criteria for the diagnosis of acute infarction in the presence of left bundle-branch block.
The base-line electrocardiograms of patients enrolled in the GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) trial who had left bundle-branch block and acute myocardial infarction confirmed by enzyme studies were blindly compared with the electrocardiograms of control patients who had chronic coronary artery disease and left bundle-branch block. The electrocardiographic criteria for the diagnosis of infarction were then tested in an independent sample of patients presenting with acute chest pain and left bundle-branch block.
Of 26,003 North American patients, 131 (0.5 percent) with acute myocardial infarction had left bundle-branch block. The three electrocardiographic criteria with independent value in the diagnosis of acute infarction in these patients were an ST-segment elevation of 1 mm or more that was concordant with (in the same direction as) the QRS complex; ST-segment depression of 1 mm or more in lead V1, V2, or V3; and ST-segment elevation of 5 mm or more that was disconcordant with (in the opposite direction from) the QRS complex. We used these three criteria in a multivariate model to develop a scoring system (0 to 10), which allowed a highly specific diagnosis of acute myocardial infarction to be made.
We developed and validated a clinical prediction rule based on a set of electrocardiographic criteria for the diagnosis of acute myocardial infarction in patients with chest pain and left bundle-branch block. The use of these criteria, which are based on simple ST-segment changes, may help identify patients with acute myocardial infarction, who can then receive appropriate treatment.
心电图上左束支传导阻滞的存在可能掩盖急性心肌梗死的变化，从而延误对其的识别和治疗。我们测试了用于诊断存在左束支传导阻滞时急性梗死的心电图标准。
对参加GUSTO-1（全球应用链激酶和组织型纤溶酶原激活剂治疗闭塞冠状动脉）试验且有左束支传导阻滞并经酶学研究证实为急性心肌梗死的患者的基线心电图，与患有慢性冠状动脉疾病和左束支传导阻滞的对照患者的心电图进行盲法比较。然后在一组表现为急性胸痛和左束支传导阻滞的独立患者样本中测试用于诊断梗死的心电图标准。
在26003名北美患者中，131名（0.5%）急性心肌梗死患者有左束支传导阻滞。在这些患者中，对急性梗死诊断具有独立价值的三个心电图标准是：ST段抬高1毫米或更多且与QRS波群同向（一致）；V1、V2或V3导联ST段压低1毫米或更多；ST段抬高5毫米或更多且与QRS波群异向（相反）。我们在多变量模型中使用这三个标准建立了一个评分系统（0至10分），该系统可对急性心肌梗死进行高度特异性的诊断。
我们基于一组心电图标准制定并验证了一项临床预测规则，用于诊断胸痛且有左束支传导阻滞患者的急性心肌梗死。使用这些基于简单ST段变化的标准可能有助于识别急性心肌梗死患者，进而使他们得到适当的治疗。
