title: Is the 12-lead electrocardiogram during antidromic circus movement tachycardia helpful in predicting the ablation site in atriofascicular pathways?
abstract: OBJECTIVE
  Unlike in the Wolff-Parkinson-White syndrome, there has been no systematic study on the role of the pre-excitation pattern in predicting the ablation site in patients with atriofascicular (AF) pathways. We assessed in a large cohort the value of the 12-lead electrocardiogram (ECG) during antidromic tachycardia (ADT) to predict the site of ablation.
  
  
  RESULTS
  Forty-five patients were studied, 23 males (51%), mean age of 27 ± 12 years with 46 AF pathways and 48 ADT using the AF pathway for A-V conduction. Inclusion required induction of a sustained ADT and successful ablation. Ablation site was assessed during LAO 45° projection and clockwise classified as hours in posteroseptal, posterolateral, lateral, anterolateral, and anteroseptal tricuspid annulus as follows: 05:00-07:00, >07:00-08:00, >08:00-09:00, >09:00-11:00, and >11:00-13:00 o'clock. The QRS axis was assessed during ADT and classified as normal (>+15°), horizontal (+15° to -30°), and superior (<-30°). During ADT axis was superior (-57° ± 10°) in 15 (31%), horizontal (-11° ± 14°) in 22 (46%), and normal (+45° ± 16°) in 11 (23%) patients. The correct ablation site did not differ between the different groups of QRS axis. QRS width during ADT was narrower in patients with a normal when compared with a horizontal and leftward axis (127 ± 14 vs. 145 ± 12 ms, P < 0.0001), and the V-H interval was shorter (4 ± 3 ms vs. 19 ± 22 ms, P = 0.03).
  
  
  CONCLUSIONS
  There was no correlation between the AF pathway ablation site and the QRS axis during ADT. The 12-lead ECG during maximal pre-excitation does not predict the proper site of tricuspid annulus ablation in patients with A-V conduction over an AF pathway.
authors.affiliation: Arrhythmia and Electrophysiology Unit, Biocor Instituto, Nova Lima, Brazil Instituto de Pós Graduação, Faculdade de Ciências Médicas de Minas Gerais, Belo Horizonte, Brazil eduardosternick@terra.com.br.
authors.forename: Eduardo Back
authors.initials: EB
authors.lastname: Sternick
authors.affiliation: Arrhythmia Associates, Mumbai, India.
authors.forename: Yash
authors.initials: Y
authors.lastname: Lokhandwala
authors.affiliation: UN Mehta Institute of Cardiology and Research Centre, Ahmedabad, India.
authors.forename: Shomu
authors.initials: S
authors.lastname: Bohora
authors.affiliation: University Hospital, Maastricht, The Netherlands.
authors.forename: Carl
authors.initials: C
authors.lastname: Timmermans
authors.affiliation: Arrhythmia and Electrophysiology Unit, Biocor Instituto, Nova Lima, Brazil.
authors.forename: Priscila Reis
authors.initials: PR
authors.lastname: Martins
authors.affiliation: Arrhythmia and Electrophysiology Unit, Biocor Instituto, Nova Lima, Brazil.
authors.forename: Liana Valadão
authors.initials: LV
authors.lastname: Dias
authors.affiliation: Arrhythmia and Electrophysiology Unit, Biocor Instituto, Nova Lima, Brazil.
authors.forename: Frederico Soares
authors.initials: FS
authors.lastname: Correia
authors.affiliation: CARIM-Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands.
authors.forename: Hein J J
authors.initials: HJ
authors.lastname: Wellens
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology / Q000601:surgery*; D001938:Brazil; D017115:Catheter Ablation; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013610:Tachycardia / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult
keywords: Atriofascicular pathway; Catheter ablation; Mahaim fiber; Mapping; Radiofrequency