title: [Post-extrasystolic potentiation in chronic Chagas' heart disease. A radiologic contrast ventriculography study].
abstract: OBJECTIVE
  To determine the existence and frequency of the phenomenon of post-extrasystolic potentiation in dyssynergic myocardial areas of patients with chronic Chagas' heart disease studied by use of radiologic contrast ventriculography.
  
  
  METHODS
  This study is a semiquantitative retrospective analysis of radiologic contrast ventriculography in patients with chronic Chagas' disease, who were consecutively studied to assess the mechanisms of ventricular tachycardia.
  
  
  RESULTS
  Of the 72 patients initially included, in only 20 patients was possible the ventriculographic analysis for the purposes of this study. The phenomenon of post-extrasystolic potentiation was observed in 11 (55%) of these patients, and a 15.31% improvement was observed in the contractility score from the baseline to the post-extrasystole condition (P=0.0001). That phenomenon occurred even in ventricular segments with an intense deficit in contractility.
  
  
  CONCLUSIONS
  The phenomenon of post-extrasystolic potentiation is observed in a significant proportion of patients with chronic Chagas' heart disease, in whom the phenomenon could be angiographically analyzed, indicating the existence of potentially recruitable contractile reserve in ventricular regions, showing marked dyssynergy. Additional studies for clarifying the underlying mechanisms are required.
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, USP, Ribeirão Preto, SP.
authors.forename: José Mário M
authors.initials: JM
authors.lastname: Brandão
authors.forename: Andrea
authors.initials: A
authors.lastname: Miziara
authors.forename: Geraldo Luiz de
authors.initials: GL
authors.lastname: Figueiredo
authors.forename: Moysés O
authors.initials: MO
authors.lastname: Lima-Filho
authors.forename: Elias M
authors.initials: EM
authors.lastname: Ayres-Neto
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Marin-Neto
mesh_terms: D014355:Chagas Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002908:Chronic Disease; D003287:Contrast Media; D006339:Heart Rate; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology*; D015635:Radionuclide Ventriculography; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D018879:Ventricular Premature Complexes / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D003287:Contrast Media