title: Safety and efficacy of cryoablation of accessory pathways adjacent to the normal conduction system.
abstract: Cryoablation of Septal Accessory Pathways.
  
  
  BACKGROUND
  Catheter ablation has become a routine treatment for patients with Wolff-Parkinson-White syndrome because of its low risk and high efficacy; however, radiofrequency ablation in the septum close to the AV node or His bundle still carries a definite risk for AV block. Cryoenergy catheter ablation has recently become available. This technique has specific features, such as the ability to create reversible loss of function to predict the effects of ablation (ice mapping) and the adherence of the catheter tip to the endocardium with freezing, which avoids the risk for dislodgment. Both of these characteristics may minimize the risk of complications. The aim of this study was to analyze the effectiveness and safety of catheter cryoablation in 20 patients with para-Hisian or midseptal accessory pathways (AP).
  
  
  RESULTS
  Eleven patients with para-Hisian and 9 patients with midseptal AP underwent catheter cryoablation. Ice mapping at -30 degrees C was performed to ascertain the disappearance of AP conduction and the absence of impairment of AV nodal conduction. If the expected result was obtained, cryoablation was performed by lowering the temperature to -75 degrees C for 4 minutes in order to create a permanent lesion. Cryoablation was successful in all patients using a mean of 1.2 +/- 0.4 applications. Recurrences occurred in 4 patients (20%) who underwent a second successful cryoablation session. No complications were observed.
  
  
  CONCLUSIONS
  Cryoablation appears to be a safe and effective technique for ablation of APs close to the AV node or His bundle because of the ability to predict the acute effects of ablation with ice mapping before creation of an irreversible lesion.
authors.affiliation: Division of Cardiology, Ospedale Mauriziano di Torino, Torino, Italy. fgaita@mauriziano.it
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Gaita
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.forename: Carla
authors.initials: C
authors.lastname: Giustetto
authors.forename: Stefano
authors.initials: S
authors.lastname: Grossi
authors.forename: Enrico
authors.initials: E
authors.lastname: Caruzzo
authors.forename: Francesca
authors.initials: F
authors.lastname: Bianchi
authors.forename: Elena
authors.initials: E
authors.lastname: Richiardi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Riccardi
authors.forename: Meleze
authors.initials: M
authors.lastname: Hocini
authors.forename: Pierre
authors.initials: P
authors.lastname: Jais
mesh_terms: D001145:Arrhythmias, Cardiac / Q000209:etiology; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D006329:Heart Conduction System / Q000002:abnormalities* / Q000601:surgery*; D006343:Heart Septal Defects / Q000601:surgery*; D006801:Humans; D010146:Pain / Q000209:etiology; D012008:Recurrence; D016896:Treatment Outcome; D014927:Wolff-Parkinson-White Syndrome / Q000601:surgery*