Davies M J
Acta Cardiol. 1976;Suppl 21:19-30.
Study of 177 cases of permanent A-V block shows idiopathic bilateral bundle branch fibrosis to be the commonest single cause (33%). This entity covers a spectrum of localised loss of conduction fibres in the proximal left bundle branch and bifurcating main bundle (Lev's disease) to moore periphery loss of conduction fibres in the bundle branches alone (Lenègre's disease). The aetiological factors in idiopathic bundle branch fibrosis are still obscure. Ischaemic damage is responsible for 17% of cases and are usually patients who have survived destruction of the bundle branches in septal infarction. Calcific A-V block is the term applied to destruction of the main bundle by large masses of calcification in the mitral or aortic valve rings and is responsible for 10% of cases of chronic A-V block. The mass of calcium is visible to the naked eye at autopsy or by X ray in life. Cardiomyopathies of all types (except hypertrophic obstructive cardiomyopathy) involve the conduction system and produce 14% of cases of A-V block. The remaining numerous causes of chronic A-V block are individually very rare ranging through tumour involvement, congenital defects, collagen diseases and surgical or traumatic damage.
对177例永久性房室传导阻滞患者的研究表明，特发性双侧束支纤维化是最常见的单一病因（33%）。这种病变涵盖了从左束支近端和分叉主束中传导纤维的局部丧失（Lev病）到仅束支中传导纤维更外周丧失（Lenègre病）的一系列情况。特发性束支纤维化的病因仍不清楚。缺血性损伤占病例的17%，通常是在间隔梗死中束支遭到破坏后存活下来的患者。钙化性房室传导阻滞是指二尖瓣或主动脉瓣环大量钙化破坏主束，占慢性房室传导阻滞病例的10%。在尸检时肉眼可见钙块，或在生前通过X线可见。所有类型的心肌病（肥厚性梗阻性心肌病除外）都会累及传导系统，导致14%的房室传导阻滞病例。慢性房室传导阻滞的其余众多病因各自都非常罕见，包括肿瘤累及、先天性缺陷、胶原疾病以及手术或创伤性损伤。
