title: Randomized comparison of anatomical versus voltage guided ablation of the cavotricuspid isthmus for atrial flutter.
abstract: OBJECTIVE
  The purpose of this prospective study was to compare radiofrequency catheter ablation of the cavotricuspid isthmus using a strictly anatomic approach to an approach guided by a bipolar voltage map to avoid high voltage zones in the cavotricuspid isthmus.
  
  
  BACKGROUND
  It is not clear whether local atrial electrogram amplitude influences the achievement of complete cavotricuspid isthmus block during radiofrequency catheter ablation for atrial flutter.
  
  
  METHODS
  Thirty-two patients with atrial flutter were randomized to cavotricuspid isthmus ablation using an anatomical approach (group I, 16 patients) or guided by a bipolar voltage map (group II, 16 patients). A 3-dimensional electroanatomic mapping system and an 8-mm-tip ablation catheter were used in all patients. With the anatomical approach, an ablation line was created in the cavotricuspid isthmus at a 6 o'clock position in the 45 degree left anterior oblique projection. During voltage-guided ablation, a high-density bipolar voltage map of the cavotricuspid isthmus was created, and then contiguous applications of radiofrequency energy were delivered to create an ablation line through the cavotricuspid isthmus sites with the lowest bipolar voltage.
  
  
  RESULTS
  Complete cavotricuspid isthmus conduction block was achieved in 100% of patients in each group. The mean maximum voltages along the line were 3.6 +/- 1.5 mV in group I, and 1.2 +/- 0.9 mV in group II (P < .01). Creating a high-density voltage map was associated with approximately 15-minute increase in the total procedure time (P = .2). During a mean follow-up of 177 +/- 40 days, there were no recurrences of atrial flutter in either group. There were no complications in either group.
  
  
  CONCLUSIONS
  When cavotricuspid isthmus ablation for atrial flutter is performed with an 8-mm-tip catheter, complete block can be achieved in all patients regardless of local voltage. Ablation of high voltage zones is not associated with a higher recurrence rate. Therefore, anatomic ablation without voltage mapping is the preferred initial approach for cavotricuspid isthmus ablation.
authors.affiliation: Division of Cardiology, University of Michigan, Ann Arbor, 48109, USA.
authors.forename: Burr
authors.initials: B
authors.lastname: Hall
authors.forename: Srikar
authors.initials: S
authors.lastname: Veerareddy
authors.forename: Peter
authors.initials: P
authors.lastname: Cheung
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Kristina
authors.initials: K
authors.lastname: Lemola
authors.forename: Jihn
authors.initials: J
authors.lastname: Han
authors.forename: Tamirisa
authors.initials: T
authors.lastname: Kamala
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
mesh_terms: D001282:Atrial Flutter / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006327:Heart Block; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014261:Tricuspid Valve / Q000503:physiopathology / Q000601:surgery*