title: Ablation of atypical atrial flutter guided by the use of concealed entrainment in patients without prior cardiac surgery.
abstract: BACKGROUND
  Mapping techniques have not been systematically evaluated with respect to atypical atrial flutter (AF) not involving the inferior vena cava isthmus. The purpose of this study was to assess prospectively the use of concealed entrainment (CE) in mapping of AF and to assess the clinical benefit of ablation of clinically relevant atypical AF.
  
  
  RESULTS
  In seven consecutive patients without prior cardiac surgery presenting with atypical AF, mapping was performed in the right and, if necessary, left atrium. At sites with CE, radiofrequency energy was delivered. In a posthoc analysis, the endocardial activation time, stimulus-flutter wave (F) interval, presence of split potentials and diastolic potentials, and postpacing interval were assessed, and effective sites were compared to ineffective sites. A total of 22 forms of atypical AF either could be induced or were present at the time of the study. Eleven of the 13 targeted atypical AFs (85%) were successfully ablated. The positive predictive value of CE increased from 45% to 75% in the presence of matching electrogram-F and stimulus-F intervals or if flutter terminated during entrainment pacing, and to 88% in the presence of split atrial electrograms or diastolic potentials. During short-term clinical follow-up, none of the patients had recurrence of the ablated AF. However, the majority of patients required either medication for atrial fibrillation or repeated interventions for new forms of AF.
  
  
  CONCLUSIONS
  Mapping and ablation of atypical AF is feasible if sites with CE can be identified. However, the clinical benefit of successful ablations in patients with atypical flutter appears to be limited.
authors.affiliation: Division of Cardiology, JW Goethe University, Frankfurt, Germany. bogun@uni-frankfurt.de
authors.forename: F
authors.initials: F
authors.lastname: Bogun
authors.forename: B
authors.initials: B
authors.lastname: Bender
authors.forename: Y G
authors.initials: YG
authors.lastname: Li
authors.forename: S H
authors.initials: SH
authors.lastname: Hohnloser
mesh_terms: D000328:Adult; D000368:Aged; D001282:Atrial Flutter / Q000503:physiopathology* / Q000601:surgery*; D006328:Cardiac Catheterization; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies