title: Early repolarization in Wolff-Parkinson-White syndrome: prevalence and clinical significance.
abstract: OBJECTIVE
  Idiopathic ventricular fibrillation (IVF) with early repolarization (ER) has recently been reported; however, ER is a common finding in healthy subjects and is also found sporadically in patients with Wolff-Parkinson-White (WPW) syndrome. The present study was designed to evaluate the prevalence and clinical significance of ER in patients with WPW syndrome.
  
  
  RESULTS
  One hundred and eleven patients with WPW syndrome were studied retrospectively. Early repolarization was defined as QRS slurring or notching with J-point elevation ≥ 1 mm. The prevalence of ER was determined before and after successful catheter ablation. Before ablation, ER was found in 35 of 75 patients with a left free wall, 6 of 23 with a right free wall, and 7 of 13 with a septal accessory pathway (48 of 111, 43% as a whole). Early repolarization was always observed in leads with positive deflection of the initial part of the delta wave. After successful ablation of accessory pathways, ER was preserved in 28 (25%), disappeared in 20 (18%), and newly developed in 8 (7%) patients. In the remaining 55 (50%) patients, ER was not observed either before or after ablation. In patients with persistent ER, the amplitude and width of ER were significantly decreased 3-7 days after the ablation (1.7 ± 0.7 vs. 1.4 ± 0.6 mm, P < 0.005 and 42 ± 11 vs. 34 ± 9 ms, P < 0.001, respectively).
  
  
  CONCLUSIONS
  In patients with WPW syndrome, ER could be partly related to early depolarization through the accessory pathway. However, persistent ER and new ER appearing after the ablation were frequently found. Therefore, in these patients, mechanisms other than early depolarization may be involved in the genesis of ER.
authors.affiliation: Second Department of Internal Medicine, Graduate School of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. kmizu@med.u-toyama.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Mizumaki
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nishida
authors.forename: Jotaro
authors.initials: J
authors.lastname: Iwamoto
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsuneda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Masao
authors.initials: M
authors.lastname: Sakabe
authors.forename: Akira
authors.initials: A
authors.lastname: Fujiki
mesh_terms: D000328:Adult; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012032:Refractory Period, Electrophysiological / Q000502:physiology*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000453:epidemiology* / Q000503:physiopathology*; D014927:Wolff-Parkinson-White Syndrome / Q000453:epidemiology* / Q000503:physiopathology* / Q000601:surgery; D055815:Young Adult