title: Vectorcardiographic predictors of ventricular arrhythmia inducibility in patients with tetralogy of Fallot.
abstract: BACKGROUND
  Vectorcardiography (VCG) may have predictive value in Tetralogy of Fallot (TOF) patients undergoing ventricular arrhythmia inducibility (VAI) electrophysiology studies (EPs).
  
  
  METHODS
  Blinded, retrospective analyses of 37 adult TOF patients undergoing EPs prior to pulmonary valve replacements were performed (21 female, median age 37years). VAI was evaluated from EPs and resting 12-lead electrocardiograms, respectively using QRS and heart rate adjusted Q-T intervals, spatial QRS-T angles (peaks), T-wave and QRS-wave (QRSwave vc) component vector root mean squares. Differences were assessed (Student t-tests, Mann Whitney U-tests, Analysis of Variance). Relative risks were calculated.
  
  
  RESULTS
  16 patients had VAI (6 monomorphic, 10 polymorphic). Only the QRSwave vc showed significant differences between those with and without VAI, 10.5±2.4 dmV vs. 13.9±4.5dmV, respectively (p=0.002), area under the ROC curve of 0.78 and relative risk of 2.52.
  
  
  CONCLUSIONS
  VCG evidence of depolarization differences was significant between TOF patients with and without inducible VA.
authors.affiliation: Children's Hospital of Colorado, Aurora, USA; University of Colorado, Aurora, USA. Electronic address: dr.danielcortez@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cortez
authors.affiliation: Children's Hospital of Colorado, Aurora, USA; University of Colorado, Aurora, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Ruckdeschel
authors.affiliation: Children's Hospital of Colorado, Aurora, USA; University of Colorado, Aurora, USA.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: McCanta
authors.affiliation: Children's Hospital of Colorado, Aurora, USA; University of Colorado, Aurora, USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Collins
authors.affiliation: University of Colorado, Aurora, USA.
authors.forename: William
authors.initials: W
authors.lastname: Sauer
authors.affiliation: Children's Hospital of Colorado, Aurora, USA; University of Colorado, Aurora, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kay
authors.affiliation: University of Colorado, Aurora, USA.
authors.forename: Duy
authors.initials: D
authors.lastname: Nguyen
mesh_terms: D000328:Adult; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology; D013771:Tetralogy of Fallot / Q000150:complications* / Q000503:physiopathology; D014672:Vectorcardiography
keywords: Tetralogy of Fallot; Vectorcardiography; Ventricular tachycardia