title: [The histopathology of the trabecular section of the right branch of the bundle of His in chronic chagasic patients with a right bundle-branch block].
abstract: OBJECTIVE
  To evaluate possible morphological changes in chronic chagasic of the right bundle trabecular branch (RB) with right branch block (RBB) and to draw clinicopathological correlations.
  
  
  METHODS
  Eight RBB chronic chagasic septo-marginal trabeculae (SMT) (group A), six left branch block (LBB) chagasic SMT (group B) and six SMT from non-chagasics with no heart disease (group C) were analyzed. Every SMT was completely embedded in paraffin, sub-serially sectioned to the end of the paraffin-block and the sections were processed for pathological study.
  
  
  RESULTS
  Right bundle branch trabecular segment mononuclear infiltrate and/or fibrosis were found for 87.5 (7/8) of group A, 50% (3/6) of group B and 16.6% (1/6) of group C. Moderate mononuclear infiltrate and fibrosis were noted respectively for 3 and 1 cases, from group A. For the remaining group A cases and for all the group B and C cases the mononuclear infiltrate and fibrosis were slight.
  
  
  CONCLUSIONS
  The frequency and degree of RB lesions might explain some of RBB. On the other hand, the absence of lesions in one case RBB and the slight degree of RB lesions in chagasics with LBB and in one non-chagasic case indicate that sometimes it is not possible to establish electrocardiographic-pathological correlations after TSM histological examination.
authors.affiliation: Hospital de Clínicas, Universidade Federal de Uberlândia, MG.
authors.forename: A
authors.initials: A
authors.lastname: Rocha
authors.forename: J L
authors.initials: JL
authors.lastname: Lima Filho
authors.forename: Z
authors.initials: Z
authors.lastname: Silva
authors.forename: R A
authors.initials: RA
authors.lastname: Heredia
authors.forename: E R
authors.initials: ER
authors.lastname: Lopes
mesh_terms: D000328:Adult; D000368:Aged; D002036:Bundle of His / Q000473:pathology*; D002037:Bundle-Branch Block / Q000473:pathology*; D002598:Chagas Cardiomyopathy / Q000473:pathology*; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
vernacular_title: Histopatologia da porção trabecular do ramo direito do feixe de His em chagásicos crônicos com bloqueio de ramo direito.