title: Electrophysiological characteristics and radiofrequency ablation of accessory pathways with slow conductive properties.
abstract: BACKGROUND
  Atrioventricular accessory pathways (AP) with unusually long ventriculo-atrial (VA) conduction times are present in a significant subset of patients with the Wolff-Parkinson-White (WPW) syndrome, not including patients with the permanent form of atrioventricular junctional reciprocating tachycardia.
  
  
  RESULTS
  We compared the electrophysiological characteristics and outcomes after radiofrequency (RF) ablation in 34 patients with the WPW syndrome, a VA interval >80 ms, and paroxysmal tachycardia with an RP/PR ratio <1 (the slow group), vs 80 patients with WPW syndrome and a VA interval <80 ms (the fast group). AP were found in the posteroseptal region significantly more often in the slow than in the fast group. In addition, the decremental conductive properties of the AP were more common in the slow than in the fast group. Catheter ablation of AP was highly successful in both groups, although ablation required a greater number of RF applications and longer procedure times in the slow group, especially for AP with decremental conductive properties.
  
  
  CONCLUSIONS
  A posteroseptal AP location was more common in AP associated with long conduction times than in AP with typical conductive properties. Both types of AP were successfully ablated, although the slow group required longer procedures and more RF energy deliveries.
authors.affiliation: Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Showa-machi, Maebashi, Gunma, Japan. MamiMamo@aol.com
authors.forename: Mamoru
authors.initials: M
authors.lastname: Manita
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
authors.forename: San-Jou
authors.initials: SJ
authors.lastname: Yeh
authors.forename: Ming-Shien
authors.initials: MS
authors.lastname: Wen
authors.forename: Chun-Chieh
authors.initials: CC
authors.lastname: Wang
authors.forename: Fun-Chung
authors.initials: FC
authors.lastname: Lin
authors.forename: Delon
authors.initials: D
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology; D006328:Cardiac Catheterization; D017115:Catheter Ablation; D002648:Child; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013614:Tachycardia, Paroxysmal / Q000209:etiology; D013617:Tachycardia, Supraventricular / Q000209:etiology; D013997:Time Factors; D014927:Wolff-Parkinson-White Syndrome / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*