title: The effects of surgically induced right bundle branch block on left ventricular function after closure of the ventricular septal defect.
abstract: OBJECTIVE
  To determine the long-term significance of right bundle branch block on left ventricular systolic and diastolic function in children subsequent to surgical closure of ventricular septal defect.
  
  
  METHODS
  We studied 26 children who underwent surgical closure of a ventricular septal defect 11 +/- 2 years postoperatively by use of conventional and tissue Doppler echocardiography, comparing the findings to those obtained from a control group. Of those having surgical correction 14 had postoperative right bundle branch block.
  
  
  RESULTS
  Irrespective of the presence of right bundle branch block, the peak systolic velocity of the mitral ring was lower in those undergoing surgical correction, with values of 5.2 +/- 1.4 cm/s in those with right bundle branch block, 5.4 +/- 1.2 cm/s in those without right bundle branch block after surgical correction, and 6.6 +/- 1.0 cm/s in the control subjects (p < 0.01). In terms of diastolic function, the early septal velocity of transmitral inflow divided by the early diastolic mitral annular velocity was significantly higher in children with right bundle branch block, at 12 +/- 3.0 cm/s compared to 8.4 +/- 1.5 cm/s in the control subjects (p < 0.01), but not significantly higher in the children without right bundle branch block after correction compared to the control group. The fractional shortening percentage was similar in both patients and control subjects. The changes noted in left ventricular function were not significantly related to age at surgery, the period of follow-up, or the surgical method.
  
  
  CONCLUSIONS
  Systolic long axis function is significantly reduced in children after surgical closure of ventricular septal defects, irrespective of the presence of right bundle branch block. Diastolic dysfunction, in contrast, was observed primarily in children with post-operative right bundle branch block.
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Skejby, Aarhus, Denmark. thais.a.pedersen@ki.au.dk
authors.forename: Thais A L
authors.initials: TA
authors.lastname: Pedersen
authors.forename: Niels H
authors.initials: NH
authors.lastname: Andersen
authors.forename: Mette R
authors.initials: MR
authors.lastname: Knudsen
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Christensen
authors.forename: Keld E
authors.initials: KE
authors.lastname: Sørensen
authors.forename: Vibeke E
authors.initials: VE
authors.lastname: Hjortdal
mesh_terms: D000293:Adolescent; D002675:Child, Preschool; D003971:Diastole / Q000502:physiology; D004452:Echocardiography; D005260:Female; D006327:Heart Block / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D006345:Heart Septal Defects, Ventricular / Q000150:complications* / Q000601:surgery; D006801:Humans; D008297:Male; D013599:Systole / Q000502:physiology; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*