心电向量图诊断伪装性束支传导阻滞的优势

Advantages of vectorcardiogram in diagnosis of masquerading bundle branch block

伪装性束支传导阻滞(masquerading bundle branch block,MBBB)不同于单纯的左前分支阻滞(left anterior fascicular block,LAFB)合并右束支阻滞(right bundle branch block,RBBB),其心脏传导系统的病变程度严重且多呈进行性恶化;诊断依赖心电图但往往漏诊较多。结合临床实例,就其束支阻滞实质和心电向量图表现特征进行分析和论述。由于左束支后分支纤维传导障碍时,在心电向量图上表现为QRS环体中部泪点密集,而该图形的表达方式较心电图类本位曲折时间(或称室壁激动时间)更加直观,因此心电向量图有助于临床早期发现心电图难以诊断的伪装性束支传导阻滞。

Different from left anterior fascicular block(LAFB)complicated with right bundle branch block(RBBB),the lesion degree of cardiac conduction system of masquerading bundle branch block(MBBB)is more serious and usually inclined to progressive deterioration.The diagnosis of MBBB relies on electrocardiogram(ECG),yet yields high omission diagnostic rate.Combing with clinical examples,analyze and discuss the problem based on the essence of bundle branch block as well as the expressive characteristics of vectorcardiogram.When conduction disturbance occurs in some fiber of the left posterior branch,it represents in the vectorcardiogram as dacryon denseness at the middle part of QRS ring while such graphic expression is much more manifest than ECG duration of intrinsicoid deflection(or called ventricular activation time).Therefore,vectorcardiogram could help in clinically discovering MBBB which is hard to be diagnosed by ECG in early phase.