title: Correlation between electrogram morphology and standard criteria to validate bidirectional cavotricuspid block in common atrial flutter ablation.
abstract: OBJECTIVE
  Assessment of a bidirectional conduction block within the cavotricuspid isthmus (CTI) is critical during radiofrequency (RF) atrial flutter (AF) ablation. We investigated the use of bipolar atrial electrogram (BAE) morphology as an additional criterion identifying CTI block and tested it against two recognized criteria: differential pacing and reversal of the right atrial depolarization sequence during coronary sinus (CS) pacing.
  
  
  RESULTS
  An RF ablation procedure was performed during 600 ms CS pacing in 100 consecutive patients with a common AF. BAE recorded along the CTI were continuously monitored. CTI conduction block was achieved by RF ablation in all patients and a clear change in BAE polarity in the Electrogram recorded by the dipoles located on the CTI and immediately lateral to the intended line of block (RS to QR pattern) associated with a confirmed CTI conduction block was observed in all cases. BAE morphology changes predicted bidirectional CTI conduction blocks with a 100% positive and a 100% negative predictive value. At a mean follow-up of 33 +/- 11 months, there was a 5% AF recurrence rate.
  
  
  CONCLUSIONS
  Our study suggests that morphological changes in BAE recorded at sites lateral and adjacent to the target line of block may be used as a unique and robust criterion to validate CTI conduction block during AF ablation procedure.
authors.affiliation: Department of Cardiology, University Hospital Nancy, France.
authors.forename: M
authors.initials: M
authors.lastname: Andronache
authors.forename: C
authors.initials: C
authors.lastname: de Chillou
authors.forename: H
authors.initials: H
authors.lastname: Miljoen
authors.forename: I
authors.initials: I
authors.lastname: Magnin-Poull
authors.forename: M
authors.initials: M
authors.lastname: Messier
authors.forename: P
authors.initials: P
authors.lastname: Dotto
authors.forename: D
authors.initials: D
authors.lastname: Beurrier
authors.forename: T
authors.initials: T
authors.lastname: Doan
authors.forename: P
authors.initials: P
authors.lastname: Houriez
authors.forename: A
authors.initials: A
authors.lastname: Bineau-Jorisse
authors.forename: B
authors.initials: B
authors.lastname: Thiel
authors.forename: B
authors.initials: B
authors.lastname: Brembilla-Perrot
authors.forename: J L
authors.initials: JL
authors.lastname: Massing
authors.forename: N
authors.initials: N
authors.lastname: Sadoul
authors.forename: E
authors.initials: E
authors.lastname: Aliot
mesh_terms: D001282:Atrial Flutter / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006327:Heart Block / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D014261:Tricuspid Valve / Q000503:physiopathology; D014684:Venae Cavae / Q000503:physiopathology