title: Inaccuracy of Wolff-Parkinson-white accessory pathway localization algorithms in children and patients with congenital heart defects.
abstract: BACKGROUND
  ECG algorithms used to localize accessory pathways (AP) in patients with Wolff-Parkinson-White (WPW) syndrome have been validated in adults, but less is known of their use in children, especially in patients with congenital heart disease (CHD). We hypothesize that these algorithms have low diagnostic accuracy in children and even lower in those with CHD.
  
  
  METHODS
  Pre-excited ECGs in 43 patients with WPW and CHD (median age 5.4 years [0.9-32 years]) were evaluated and compared to 43 consecutive WPW control patients without CHD (median age 14.5 years [1.8-18 years]). Two blinded observers predicted AP location using 2 adult and 1 pediatric WPW algorithms, and a third blinded observer served as a tiebreaker. Predicted locations were compared with ablation-verified AP location to identify (a) exact match for AP location and (b) match for laterality (left-sided vs right-sided AP).
  
  
  RESULTS
  In control children, adult algorithms were accurate in only 56% and 60%, while the pediatric algorithm was correct in 77%. In 19 patients with Ebstein's anomaly, diagnostic accuracy was similar to controls with at times an even better ability to predict laterality. In non-Ebstein's CHD, however, the algorithms were markedly worse (29% for the adult algorithms and 42% for the pediatric algorithms). A relatively large degree of interobserver variability was seen (kappa values from 0.30 to 0.58).
  
  
  CONCLUSIONS
  Adult localization algorithms have poor diagnostic accuracy in young patients with and without CHD. Both adult and pediatric algorithms are particularly misleading in non-Ebstein's CHD patients and should be interpreted with caution.
authors.affiliation: Electrophysiology Division, Department of Cardiology, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Bar-Cohen
authors.forename: Paul
authors.initials: P
authors.lastname: Khairy
authors.forename: James
authors.initials: J
authors.lastname: Morwood
authors.forename: Mark E
authors.initials: ME
authors.lastname: Alexander
authors.forename: Frank
authors.initials: F
authors.lastname: Cecchin
authors.forename: Charles I
authors.initials: CI
authors.lastname: Berul
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D006330:Heart Defects, Congenital / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D015203:Reproducibility of Results; D014927:Wolff-Parkinson-White Syndrome / Q000150:complications*