Left bundle branch block, an old-new entity.
Left bundle branch block, an old-new entity.
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DOI：
10.1007/s12265-011-9344-5
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发表时间：
2012-04
影响因子：
3.4
通讯作者：
Breithardt, Ole-Alexander
中科院分区：
文献类型：
--
作者：
Breithardt, Guenter;Breithardt, Ole-Alexander
与正常的心室内传导相比，左束支传导阻滞（LBBB）通常与较差的预后相关，但与右束支传导阻滞相比，右束支传导阻滞通常被认为是良性的，在没有潜在的心脏疾病（如先天性心脏病）的情况下。LBBB可能是弥漫性心肌疾病的第一个表现。LBBB典型的体表心电图特征是QRS延长0.11 s以上，且V5、V6导联固有偏转延迟超过60ms，且I、V5、V6导联由于室间隔从右向左异常激活而无间隔q波。由于异常的非同步收缩模式，LBBB可能引起左心室功能异常，这可以通过双心室起搏（再同步治疗）来补偿。心室的非同步电激活引起负荷的区域差异，可能导致不对称肥厚和左室扩张，特别是由于晚激活区壁质量的增加，这可能会加重原有的左室泵送性能，甚至诱发它。特别值得关注的是LBBB、静息时左心室尺寸和射血分数正常，但运动时肺动脉压异常升高、高速率起搏时乳酸生成、心肌闪烁图显示缺血迹象（但无冠状动脉狭窄）和心肌活检超微结构异常的患者。对于这种实体，以前曾建议使用“潜伏性心肌病”一词。
Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.
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影响因子：
5.7
作者：
Becker, Michael;Franke, Andreas;Hoffmann, Rainer
通讯作者：
Hoffmann, Rainer
DOI：
10.1111/j.1540-8159.1994.tb03783.x
发表时间：
1994-11-01
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1.8
作者：
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158.5
作者：
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影响因子：
4.8
作者：
BERKOWITZ, WD;LAU, SH;DAMATO, AN
通讯作者：
DAMATO, AN