title: Prospective randomized comparison of closed cooled-tip versus 8-mm-tip catheters for radiofrequency ablation of typical atrial flutter.
abstract: BACKGROUND
  Cooled-tip and 8-mm-tip catheters have been found to be more effective than conventional 4-mm-tip catheters for radiofrequency (RF) ablation of common atrial flutter. The aim of this study was to compare the efficacy and safety of cooled-tip and 8-mm-tip catheters for flutter ablation in a randomized, prospective study.
  
  
  RESULTS
  In 100 consecutive patients referred for ablation of common atrial flutter, cavotricuspid ablation was performed with a closed cooled-tip catheter (n = 50) or an 8-mm-tip ablation catheter (n = 50). RF current was applied for 60 to 120 seconds at powers of 40 to 50 W with the closed cooled-tip catheter and in a temperature-controlled mode (65 degrees C/70 W) with the 8-mm-tip catheter. The endpoint was achievement of a bidirectional isthmus conduction block. Cross-over was performed after 15 unsuccessful RF applications for each of the catheters. Complete bidirectional isthmus block was achieved in 99% of patients. Cross-over was performed in 11 patients after primary use of the cooled-tip catheter and in 9 patients after primary ablation with the 8-mm-tip catheter. No significant differences were found in the procedure parameters, such as overall RF applications (12.4 +/- 11.3 vs 12.9 +/- 8.6), ablation duration (42 +/- 43 min vs 39 +/- 27 min), and fluoroscopy time (17.0 +/- 18.7 min vs 15.7 +/- 10.7 min). In a mean follow-up of 8.3 months, 1 patient in the cooled-tip group and 3 patients in the 8-mm-tip group had recurrence of common atrial flutter.
  
  
  CONCLUSIONS
  Use of the closed cooled-tip ablation catheter and the 8-mm-tip catheter have equal and high efficacy for RF ablation of common atrial flutter.
authors.affiliation: Deutsches Herzzentrum München and 1. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. Schreieck@dhm.mhn.de
authors.forename: Juergen
authors.initials: J
authors.lastname: Schreieck
authors.forename: Bernhard
authors.initials: B
authors.lastname: Zrenner
authors.forename: Johanna
authors.initials: J
authors.lastname: Kumpmann
authors.forename: Gjin
authors.initials: G
authors.lastname: Ndrepepa
authors.forename: Michael A E
authors.initials: MA
authors.lastname: Schneider
authors.forename: Isabel
authors.initials: I
authors.lastname: Deisenhofer
authors.forename: Claus
authors.initials: C
authors.lastname: Schmitt
mesh_terms: D000368:Aged; D001282:Atrial Flutter / Q000150:complications / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D018592:Cross-Over Studies; D004554:Electric Countershock / Q000295:instrumentation; D004567:Electrodes, Implanted; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000150:complications / Q000601:surgery; D006329:Heart Conduction System / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D012008:Recurrence; D012086:Reoperation; D016896:Treatment Outcome