title: Ablation of typical atrial flutter: a prospective randomized study of cooled-tip versus 8-mm-tip catheters.
abstract: OBJECTIVE
  Both ablation catheters with closed irrigated system and 8mm tip-catheters have been shown to be more effective for typical atrial flutter radiofrequency (RF) ablation when compared to conventional 4 mm tip catheter. Considering the differences in complexity and costs of both systems, a prospective study was designed to compare the efficacy and safety of cooled-tip and 8mm-tip catheters for atrial flutter ablation.
  
  
  METHODS
  Fifty-two consecutive patients underwent RF ablation of cavotricupsid isthmus (CTI) for the treatment of typical atrial flutter, using catheter with closed irrigation system (n=26) or 8 mm-tip catheter (n=26). The RF pulses were applied point-by-point for 60 seconds, with power limited at 50 w for the irrigated catheter and by temperature control (60 degrees/70 w) for the 8 mm catheter.
  
  
  RESULTS
  The CTI block was successfully performed in 98.1%. Four patients in the irrigated group needed to switch to the other group. There was no significant difference with regard to ablation parameters, such as total time of RF ablation (591.1+/-309.0 s vs 486.2+/-250.8 s), total procedure duration (86.4+/-23.6 vs 78.1+/-22.5 min) and time of fluoroscopy (17.0+/-6.7 vs 15.4+/-4.6 min). During follow-up of 10.6 months in average, one patient in the irrigated group had recurrence of typical atrial flutter.
  
  
  CONCLUSIONS
  Efficacy and safety of CTI ablation was comparable between both techniques (irrigated catheter and 8 mm-tip catheter). The complexity of irrigated catheter makes it less competitive.
authors.affiliation: Instituto do Coração, Hospital das Clínicas, FM, USP, São Paulo, SP, Brazil.
authors.forename: Sissy L
authors.initials: SL
authors.lastname: Melo
authors.forename: Mauricio I
authors.initials: MI
authors.lastname: Scanavacca
authors.forename: Francisco C C
authors.initials: FC
authors.lastname: Darrieux
authors.forename: Denise T
authors.initials: DT
authors.lastname: Hachul
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Sosa
mesh_terms: D001282:Atrial Flutter / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000592:standards*; D002404:Catheterization / Q000295:instrumentation / Q000592:standards; D003080:Cold Temperature; D022062:Electrophysiologic Techniques, Cardiac; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D007507:Therapeutic Irrigation; D016896:Treatment Outcome; D014261:Tricuspid Valve / Q000601:surgery