Sclarovsky S, Lewin R F, Strasberg B, Agmon J
Circulation. 1979 Jul;60(1):26-32. doi: 10.1161/01.cir.60.1.26.
Thirty cases in which transient left anterior hemiblock (LAHB) obscured the diagnosis of right bundle branch block (RBBB) appearing during the first days of an acute myocardial infarction (AMI) are presented. Twenty-eight of the patients with AMI had a clear septal wall involvement, while the remaining two had an anterolateral and lateral wall AMI, respectively. These intraventricular conduction defects developed 2-120 hours (mean 64.9 +/- 26 hours) after the acute event, and persisted for 24 hours to 7 days (mean 63.1 +/- 35 hours). The ECG was characterized by a pure LAHB with wide QRS complexes and the presence of RBBB was shown by recording high V1 and right-sided chest leads. The vectorcardiogram was also useful in several cases. The clinical course of this type of bifascicular block was transient and benign, with an in-hospital mortality of 6.7%. No patient developed trifascicular or complete atrioventricular block and, therefore, we conclude that prophylactic installation of a temporary pacemaker is not indicated in this type of bifascicular block. The possible role of extracellular potassium released during acute myocardial necrosis in the pathophysiological mechanism of these blocks is discussed.
本文报告了30例急性心肌梗死（AMI）发病最初几天出现的短暂性左前分支阻滞（LAHB）掩盖右束支阻滞（RBBB）诊断的病例。28例AMI患者有明确的间隔壁受累，其余2例分别为前侧壁和侧壁AMI。这些室内传导缺陷在急性事件后2 - 120小时（平均64.9±26小时）出现，并持续24小时至7天（平均63.1±35小时）。心电图表现为伴有宽QRS波群的单纯LAHB，通过记录高V1导联和右侧胸导联显示存在RBBB。向量心电图在一些病例中也很有用。这种双分支阻滞的临床过程是短暂且良性的，住院死亡率为6.7%。没有患者发展为三分支或完全性房室阻滞，因此，我们得出结论，对于这种类型的双分支阻滞，不建议预防性安装临时起搏器。讨论了急性心肌坏死期间释放的细胞外钾在这些阻滞病理生理机制中的可能作用。
