title: Radiofrequency ablation of atypical atrial flutter after cardiac surgery or atrial fibrillation ablation: a randomized comparison of open-irrigation-tip and 8-mm-tip catheters.
abstract: BACKGROUND
  The efficacy of radiofrequency ablation of atypical atrial flutter (AAFL) remains relatively low. This is probably related to the complex mechanism of this arrhythmia or may be due to an inability to deliver sufficient energy during ablation.
  
  
  OBJECTIVE
  The aim of this study is to assess whether an open-irrigation-tip catheter or an 8-mm-tip catheter is more effective for ablation of AAFL in patients with prior history of cardiac surgery and/or catheter ablation of atrial fibrillation.
  
  
  METHODS
  Seventy patients with AAFL after cardiac surgery/atrial fibrillation ablation were randomized for ablation with either an open-irrigation-tip catheter (Group 1, n=36) or an 8-mm-tip catheter (Group 2, n=34). Acute success was defined as the termination of AAFL by radiofrequency delivery and noninducibility by programmed pacing at the end of procedure. Patients' postoperative courses were followed up by means of intermittent standard electrocardiogram (ECG), transtelephonic ECG monitoring, and telephone interview. All patients underwent 48-hour Holter monitoring at their 3-, 6-, and 9-month follow-up after ablation.
  
  
  RESULTS
  Acute success was achieved in 34 patients (94.4%) in Group 1 and 26 patients (76.5%) in Group 2 (P<.05). As compared with the patients in Group 2, more patients in Group 1 remained in sinus rhythm without antiarrhythmic drugs at 90-day follow-up (22 vs 8, P<.05). After 10 months of follow-up, 91.7% of the patients from Group 1 were free of atrial tachyarrhythmias, whereas only 58.9% of the patients from Group 2 remained in sinus rhythm (P <.05). The fluoroscopy and radiofrequency times were significantly shorter when an open-irrigation-tip ablation catheter was used.
  
  
  CONCLUSIONS
  In patients with a prior history of cardiac surgery or ablation for atrial fibrillation, an open-irrigation-tip catheter is superior to an 8-mm-tip catheter for radiofrequency ablation of scar-related AAFLs. Patients ablated with an open-irrigation-tip catheter seem to have higher acute success rate with less x-ray exposure and radiofrequency delivery, and have a more favorable long-term outcome with more patients maintaining sinus rhythm without antiarrhythmic drugs.
authors.affiliation: Department of Cardiovascular Medicine, Section of Cardiac Electrophysiology and Pacing, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Rong
authors.initials: R
authors.lastname: Bai
authors.forename: Tamer S
authors.initials: TS
authors.lastname: Fahmy
authors.forename: Dimpi
authors.initials: D
authors.lastname: Patel
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Biase
authors.forename: Lucie
authors.initials: L
authors.lastname: Riedlbauchova
authors.forename: Oussama M
authors.initials: OM
authors.lastname: Wazni
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schweikert
authors.forename: J David
authors.initials: JD
authors.lastname: Burkhardt
authors.forename: Walid
authors.initials: W
authors.lastname: Saliba
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000628:therapy*; D001282:Atrial Flutter / Q000628:therapy*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged