title: [Radiofrequency catheter ablation of left accessory pathways by transeptal approach].
abstract: OBJECTIVE
  To study a series of patients submitted to radiofrequency catheter ablation (RFA) of left accessory pathways (AP) using the transeptal approach (TSA) as compared to the conventional retrograde arterial approach (RAA).
  
  
  METHODS
  One hundred consecutive patients (56 male; mean age of 34.3 +/- 11 years) with 100 left APs (62 overt and 38 concealed) underwent catheter ablation using the TS method (50 patients) and the RA method (50 patients) in an alternate fashion. The analysis was performed according to the intention-to-treat principle.
  
  
  RESULTS
  The transeptal puncture was successfully performed in 48 patients (96%). This access allowed primary success in the ablation in all the patients without any complication. When we compared this approach with the RAA there was no difference as regards the primary success (p = 0.2), recurrence rate (p = 1.0), fluoroscopy time (p = 0.63) and total time (p = 0.47). One patient in the RAA group presented a vascular complication. The TSA allowed shorter ablation times (p=0.01) and smaller number of radiofrequency applications (p = 0.003) as compared to the conventional RAA. The patients who had recurrence and unsuccessful ablation in the first session in each approach underwent another session with the opposite technique (cross-over), with a final ablation success rate of 100%.
  
  
  CONCLUSIONS
  The TS and RA approaches showed similar efficacy and safety for the ablation of left accessory pathways. The TSA allowed shorter ablation times and smaller number of radiofrequency applications. When the techniques were used in a complementary fashion, they increased the final efficacy of the ablation.
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba. masilva@cardiol.br
authors.forename: Márcio Augusto
authors.initials: MA
authors.lastname: Silva
authors.forename: Elenir
authors.initials: E
authors.lastname: Nadalin
authors.forename: Alessandro
authors.initials: A
authors.lastname: Kraemmer
authors.forename: Gel Roberto Marmitt
authors.initials: GR
authors.lastname: Berardi
authors.forename: José Carlos Moura
authors.initials: JC
authors.lastname: Jorge
authors.forename: Cláudio L Pereira
authors.initials: CL
authors.lastname: da Cunha
mesh_terms: D000293:Adolescent; D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006346:Heart Septum / Q000601:surgery*; D006352:Heart Ventricles / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D012008:Recurrence; D013617:Tachycardia, Supraventricular / Q000601:surgery*; D016896:Treatment Outcome