title: Selective atrial vagal denervation guided by evoked vagal reflex to treat patients with paroxysmal atrial fibrillation.
abstract: BACKGROUND
  The aim of this study was to evaluate whether selective radiofrequency (RF) catheter ablation of the atrial sites in which high-frequency stimulation induces vagal reflexes prevents paroxysmal atrial fibrillation (AF).
  
  
  RESULTS
  Ten patients with episodes suggestive of vagal-induced paroxysmal AF and no heart disease were selected for percutaneous epicardial and endocardial mapping of the atria to search for sites in which high-frequency transcatheter stimulation (20 Hz,) induced vagal reflexes. A vagal response defined as AV block of > 2 seconds was elicited in 7 of 10 patients (70%) with an average of 5 +/- 2.4 (range, 2 to 9) sites per patient, and RF pulses (21.0 +/- 12.0 per patient) were applied at those sites to eliminate all evoked vagal reflexes. The 3 patients in whom evoked vagal reflexes were not obtained underwent circumferential pulmonary vein ablation with an average of 58.0 +/- 13.9 RF pulses per patient (P = 0.022). Autonomic evaluation was performed before and 48 hours and 3 months after the procedure and was consistent with vagal withdrawal in all patients. Two of the 7 patients who underwent denervation remained asymptomatic without the use of antiarrhythmic medication at a mean follow-up of 8.3 +/- 2.8 months (range, 5 to 15 months); 4 had frequent recurrences and were referred for circumferential pulmonary vein ablation; and 1 had few AF episodes without antiarrhythmic medication. The 3 patients without evoked vagal reflexes who underwent circumferential pulmonary vein ablation remained asymptomatic without antiarrhythmic medication. One patient had acute delayed gastric emptying after atrial vagal denervation.
  
  
  CONCLUSIONS
  RF catheter ablation of selected atrial sites in which high-frequency stimulation induced vagal reflexes may prevent AF recurrences in selected patients with apparently vagal-induced paroxysmal AF.
authors.affiliation: Unidade Clínica de Arritmia, Heart Institute, University of São Paulo Medical School, Av Dr Eneas Carvalho de Aguiar 44, CEP 05403-000, São Paulo/SP, Brazil. mauricio.scanavacca@incor.usp.br
authors.forename: Mauricio
authors.initials: M
authors.lastname: Scanavacca
authors.forename: Cristiano F
authors.initials: CF
authors.lastname: Pisani
authors.forename: Denise
authors.initials: D
authors.lastname: Hachul
authors.forename: Sissy
authors.initials: S
authors.lastname: Lara
authors.forename: Carina
authors.initials: C
authors.lastname: Hardy
authors.forename: Francisco
authors.initials: F
authors.lastname: Darrieux
authors.forename: Ivani
authors.initials: I
authors.lastname: Trombetta
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Negrão
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sosa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D003714:Denervation; D004594:Electrophysiology / Q000379:methods; D006329:Heart Conduction System / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D012146:Rest / Q000502:physiology; D012890:Sleep / Q000502:physiology; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000503:physiopathology*
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone