title: QRS duration changes in patients with hypoplastic left heart syndrome undergoing hybrid palliation: prehybrid to post-Fontan.
abstract: BACKGROUND
  QRS prolongation has been shown to be a predictor of mortality in patients with certain forms of congenital heart disease. QRS changes have not been well described in patients with single ventricle physiology, particularly in those undergoing the hybrid procedure.
  
  
  OBJECTIVE
  To describe QRS changes in a cohort of patients with hypoplastic left heart syndrome (HLHS) who underwent hybrid palliation and to evaluate if QRS duration is associated with mortality.
  
  
  METHODS
  Chart review of 54 patients with HLHS who underwent hybrid procedure between 2002 and 2009 was performed. Patients awaiting surgical palliation were excluded. Patients who survived Fontan completion (HLHS-S, n = 30) were compared to non-survivor (HLHS-NS, n = 24). Electrocardiograms were reviewed for maximal QRS duration (ms) at three pre- and postsurgical stages: (1) hybrid procedure, (2) comprehensive stage 2 procedure, and (3) Fontan procedure.
  
  
  RESULTS
  In HLHS-S, there was a significant increase in QRS from birth to Fontan completion (15.6 ± 9.3 ms). QRS duration increased 8.5 ± 8.9 ms between posthybrid to precomprehensive stage 2, and 5.4 ± 9.7 ms between postcomprehensive stage 2 to Fontan. Following Fontan procedure, mean QRS decreased 4.3 ± 8.5 ms. There was no significant mean difference in QRS change between HLHS-S and HLHS-NS following hybrid procedure. Pre- and posthybrid and pre- and postcomprehensive stage 2 QRS durations were not different between HLHS-S and HLHS-NS who underwent a comprehensive stage 2 procedure. There was a significant difference in QRS difference following comprehensive stage 2 in HLHS-S (0.9 ± 7.1 ms) compared to HLHS-NS (-7.1 ± 10.0 ms).
  
  
  CONCLUSIONS
  QRS duration significantly increased from hybrid to Fontan completion in HLHS-S. There was a significant decrease in QRS duration in patients who died following comprehensive stage 2 procedure. Larger studies are needed to assess the significance of these QRS changes.
authors.affiliation: Heart Center, Nationwide Children's Hospital, Columbus, Ohio, USA.
authors.forename: Shane
authors.initials: S
authors.lastname: Tsai
authors.forename: Nazia
authors.initials: N
authors.lastname: Husain
authors.forename: Abigail
authors.initials: A
authors.lastname: Fischer
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Ro
authors.forename: John P
authors.initials: JP
authors.lastname: Cheatham
authors.forename: Mark
authors.initials: M
authors.lastname: Galantowicz
authors.forename: Clifford L
authors.initials: CL
authors.lastname: Cua
mesh_terms: D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D018729:Fontan Procedure / Q000401:mortality; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000401:mortality / Q000503:physiopathology* / Q000601:surgery*; D007223:Infant; D008297:Male; D010166:Palliative Care; D012189:Retrospective Studies; D016896:Treatment Outcome