title: Effects of slow pathway ablation on fast pathway function in patients with atrioventricular nodal reentrant tachycardia: cryo- vs. radiofrequency ablation.
abstract: BACKGROUND
  In typical atrioventricular nodal reentrant tachycardia, radiofrequency (RF) ablation of the slow pathway (SP) is known to change the effective refractory period of the fast pathway (ERP(FP)) after successful RF ablation of the SP. The purpose of this study was to ascertain the mechanism of the ERP(FP) changes after SP ablation by comparing the results of both cryo- and RF ablation.
  
  
  RESULTS
  A total of 112 patients were enrolled prospectively and their electrophysiological properties analyzed before and after successful SP ablation. Patients were grouped into cryoablation (n=54) and RF ablation (n=58) groups and each group was subdivided into complete ablation (CG) and modification (MG) based on the presence of the SP after successful ablation. CG was performed in 64 patients: 30 by cryoablation and 34 by RF ablation. In patients who underwent complete SP ablation, the ERP(FP) was shortened significantly after cryoablation (375 ± 74 vs. 281 ± 39 ms, P<0.01), without significant change in the atrio-His (AH) or sinus cycle length (SCL) interval. Similarly, the ERP(FP) was shortened significantly (358 ± 106 vs. 289 ± 84 ms, P=0.01) also after RF ablation without change in AH or SCL interval.
  
  
  CONCLUSIONS
  ERP(FP) shortening was observed after complete SP ablation with both cryo- and RF ablation without significant changes in indices of autonomic activity.
authors.affiliation: Sanggye Paik Hospital, Department of Internal Medicine, University of Inje College of Medicine, Seoul, Korea.
authors.forename: Kyoung-Min
authors.initials: KM
authors.lastname: Park
authors.forename: Kyoung-Suk
authors.initials: KS
authors.lastname: Rhee
authors.forename: Eun-Sun
authors.initials: ES
authors.lastname: Jin
authors.forename: Gi-Byoung
authors.initials: GB
authors.lastname: Nam
authors.forename: Kee-Joon
authors.initials: KJ
authors.lastname: Choi
authors.forename: You-Ho
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000601:surgery*