title: Inducibility of atrial fibrillation with a synchronized external low energy shock post-pulmonary vein isolation predicts recurrent atrial fibrillation.
abstract: BACKGROUND
  Inducibility of atrial fibrillation (AF) with burst pacing after pulmonary vein (PV) isolation is associated with recurrent AF.
  
  
  OBJECTIVE
  This study evaluated whether an external 30 Joule (J) shock synchronized to the R wave, during the vulnerable period of atrial repolarization, is able to risk-stratify patients further for AF recurrence after PV isolation.
  
  
  METHODS
  One hundred and sixteen consecutive patients underwent PV isolation for AF. Atrial burst pacing was performed after PV isolation. In patients without AF induced by burst pacing, a biphasic external 30 J shock synchronized to the R wave was delivered as a further test for inducible AF. Patients were followed for a mean of 16 months, and recurrent AF was defined as more than 10 sec of AF on ambulatory monitoring.
  
  
  RESULTS
  AF was induced in 19 (16%) of patients with burst pacing. Eighty-one patients who were noninducible with burst pacing had a 30 J shock administered, which induced AF in 16 (20%). In follow-up, 21% of patients who were noninducible with burst pacing or low-energy shock vs 54% who were inducible with either test developed recurrent AF at one year (HR 3.18, P = 0.0004 on multivariate analysis). Among patients who were noninducible with burst pacing, 18% who were noninducible with a low-energy shock vs 60% who were inducible with shock developed recurrent AF at one year (HR = 4.63, P = 0.0006 on multivariate analysis).
  
  
  CONCLUSIONS
  Inducibility of AF by a 30 J shock delivered during atrial repolarization after PV isolation may predict AF recurrence. Evaluation of inducibility of AF with burst pacing and a biphasic external synchronized shock after PV isolation may help guide postprocedure management.
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA. jwylie@bidmc.harvard.edu
authors.forename: John V
authors.initials: JV
authors.lastname: Wylie
authors.forename: Vidal
authors.initials: V
authors.lastname: Essebag
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Reynolds
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D004558:Electric Stimulation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011667:Pulmonary Veins / Q000601:surgery*; D012008:Recurrence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity