title: Implication of anterior septal malalignment in isolated ventricular septal defect.
abstract: OBJECTIVE
  The aim was to define the long term prognosis of isolated ventricular septal defect (VSD) with anteriorly malaligned outlet septum.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  University hospital, tertiary medical care centre.
  
  
  METHODS
  Between July 1986 and June 1993, 63 patients were studied with an isolated VSD and anteriorly malaligned outlet septum (59 perimembranous; 4 muscular outlet).
  
  
  METHODS
  The diagnosis of septal malalignment, aneurysmal transformation, right ventricular obstruction, subaortic ridge, and aortic valve prolapse was based on echocardiographic criteria, then confirmed by angiography in 33 patients and by surgery in 28. An actuarial curve for each event was obtained by Kaplan-Meier non-parametric analysis and the significance was examined by log-rank test.
  
  
  RESULTS
  Aneurysmal transformation decreased the size of the VSD in 52% of the patients, but was also associated with the appearance of subaortic ridge (p < 0.05). Progressive obstruction in the right ventricle was observed in 51%, more often in those without aneurysmal transformation (p < 0.05). Aortic valve prolapse was quite common whether or not aneurysmal transformation occurred (33% and 23%, respectively). This was attributed to the location of the VSD and the anterior malalignment of the outlet septum. Surgery was performed in 28 patients at a median age of 50 months because of significant left to right shunt (n = 5), or the development of obstruction in right ventricle (n = 9), aortic valve prolapse (n = 3), or combinations (n = 11). The presence of subaortic ridge per se was not considered to be a surgical indication.
  
  
  CONCLUSIONS
  Anteriorly malaligned VSDs have variable presentation. Careful echocardiographic evaluation is needed to identify various combinations of progressive right ventricular obstruction, aneurysmal transformation, subaortic ridge, or aortic valve prolapse. In extreme cases a patient may have a pathology complex comprising right ventricular outflow obstruction, subaortic ridge, aortic valve prolapse, and anteriorly malaligned VSD.
authors.affiliation: Department of Pediatrics and Surgery, National Taiwan University, Taipei, Republic of China.
authors.forename: M H
authors.initials: MH
authors.lastname: Wu
authors.forename: J K
authors.initials: JK
authors.lastname: Wang
authors.forename: C I
authors.initials: CI
authors.lastname: Chang
authors.forename: I S
authors.initials: IS
authors.lastname: Chiu
authors.forename: H C
authors.initials: HC
authors.lastname: Lue
mesh_terms: D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D006345:Heart Septal Defects, Ventricular / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis