title: Atrioventricular node reentrant tachycardia in patients with a long fast pathway effective refractory period: clinical features, electrophysiologic characteristics, and results of radiofrequency ablation.
abstract: Twenty-two patients (group 1) with AV node reentrant tachycardia and a baseline fast pathway effective refractory period (ERP) > or = 500 msec were compared with 30 consecutive patients (group 2) with AV node reentrant tachycardia and a fast pathway ERP < 500 msec. Both groups underwent slow pathway ablation. In the patients with complete elimination of slow pathway, the fast pathway ERP and shortest 1:1 conduction cycle length shortened significantly after ablation but was greater in group 1 (n = 14) than in group 2 (n = 21) (125 +/- 78 msec vs 48 +/- 29 msec, p < 0.001 and 103 +/- 72 msec vs 52 +/- 30 msec, p < 0.001, respectively). In group 1, the shortening of fast pathway ERP was correlated to baseline difference between anterograde fast and anterograde slow ERP (r = 0.806, p < 0.001, slope = 1.08), and the shortening of fast pathway shortest 1:1 conduction cycle length was correlated to baseline difference between anterograde fast and anterograde slow shortest 1:1 conduction cycle length (r = 0.885, p < 0.001, slope = 1.47). During follow-up bradycardia did not develop in any patient and no one required pacing. This shortening of the fast pathway ERP and shortest 1:1 conduction cycle length after complete elimination of slow pathway reduced the concern of subsequent impairment of AV node conduction.
authors.affiliation: Division of Cardiology, National Yang-Ming University, Veterans General Hospital, Taipei, Taiwan, Republic of China.
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
authors.forename: S A
authors.initials: SA
authors.lastname: Chen
authors.forename: C T
authors.initials: CT
authors.lastname: Tai
authors.forename: C E
authors.initials: CE
authors.lastname: Chiang
authors.forename: Z C
authors.initials: ZC
authors.lastname: Wen
authors.forename: Y J
authors.initials: YJ
authors.lastname: Chen
authors.forename: W C
authors.initials: WC
authors.lastname: Yu
authors.forename: A N
authors.initials: AN
authors.lastname: Fong
authors.forename: J L
authors.initials: JL
authors.lastname: Huang
authors.forename: J J
authors.initials: JJ
authors.lastname: Cheng
authors.forename: M S
authors.initials: MS
authors.lastname: Chang
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000328:Adult; D000368:Aged; D017115:Catheter Ablation; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology* / Q000601:surgery
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol