title: A comparison of the clinical course of preexcitation syndrome in children and adolescents and in adults.
abstract: BACKGROUND
  Atrioventricular reentrant tachycardia (AVRT) in patients with preexcitation syndrome (PS) is the main cause of paroxysmal regular arrhythmias in children and adolescents. While the previously published data most commonly concern clinical consequences of PS in adults, few researchers have evaluated the problem in children and adolescents. The aim of the study was to compare the clinical course of PS between the population of children and adolescents below 19 years of age and the population of adult patients.
  
  
  METHODS
  The study population consisted of 302 consecutive PS patients managed between January 2001 and June 2005 with radiofrequency catheter ablation (RFCA). The study population was divided into two groups: Group 1 consisting of 52 patients aged 15.38 years on average (7-18 +/- +/- 2.53) and Group 2 consisting of 250 adult patients aged 38.67 years on average (19-72 +/- 13.1).
  
  
  RESULTS
  Patients from Groups 1 and 2 experienced their first episode of AVRT at the mean age of 13.3 years and 29.1 years, respectively (p < 0.05). The mean annual numbers of AVRT episodes in Groups 1 and 2 were 12.97 (range, 2-96; median, 8) and 8.86 (range, 2-25; median, 6), respectively (p = non-significant). Two patients from Group 1 (3.85%) and 42 patients from Group 2 (16.8%) experienced episodes of atrial fibrillation (AF) (p < 0.05). Location of the accessory pathways (AP): In Group 1, the right free wall and anteroseptal AP locations were significantly more common [11 (21.15%) and 9 (17.31%) patients, respectively, vs.q 19 (7.6%) and 13 (5.2%) patients in Group 2; p < 0.01]. In Group 2, the left anterolateral AP location was more common [81 (32.4%) vs. 4 (7.69%) in Group 1; p < 0.01].
  
  
  CONCLUSIONS
  In children and adolescents with PS, a significantly lower incidence of AF was found. In Group 1, RFCA was performed significantly more frequently due to the development of AVRT caused by right free wall and right anteroseptal AP, while in the group of adults, the left anterolateral AP location was found more commonly. (Cardiol J 2007; 14: 384-390).
authors.forename: Patrycja
authors.initials: P
authors.lastname: Pruszkowska-Skrzep
authors.forename: Sławomir
authors.initials: S
authors.lastname: Pluta
authors.forename: Anna
authors.initials: A
authors.lastname: Lenarczyk
authors.forename: Oskar
authors.initials: O
authors.lastname: Kowalski
authors.forename: Radosław
authors.initials: R
authors.lastname: Lenarczyk
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kurek
authors.forename: Alina
authors.initials: A
authors.lastname: Zdrzałek-Skiba
authors.forename: Beata
authors.initials: B
authors.lastname: Chodór
authors.forename: Bozena
authors.initials: B
authors.lastname: Zeifert
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Szkutnik
authors.forename: Jacek
authors.initials: J
authors.lastname: Białkowski
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kalarus