title: Radiofrequency ablation annotation algorithm reduces the incidence of linear gaps and reconnection after pulmonary vein isolation.
abstract: BACKGROUND
  A common mechanism of atrial fibrillation recurrence after catheter ablation is resumption of pulmonary vein (PV) conduction due to gaps in the ablation line. These gaps may go unrecognized owing to inadequate ablation lesion annotation.
  
  
  OBJECTIVE
  To examine the utility of an automated radiofrequency (RF) ablation annotation algorithm for the detection and treatment of ablation gaps during pulmonary vein isolation (PVI).
  
  
  METHODS
  Eighty-four patients with paroxysmal atrial fibrillation underwent PVI. In 42 patients (group A), RF ablation was guided by an automated algorithm with predefined criteria of catheter stability range of motion ≤2 mm and impedance decrease ≥5% for individual ablation applications. In 42 control patients (group B), ablation was guided by the operator. Successful PVI, conduction recovery, and dormant conduction with adenosine were compared between the groups.
  
  
  RESULTS
  Ipsilateral PVI at the completion of the initial anatomical line was obtained in 90.5% of group A patients (76 of 84 ipsilateral pairs of PVs) but only in 66.7% of group B patients (56 of 84 ipsilateral pairs of PVs) (P = .0001). Ineffective energy delivery was detected in 23% (1005 of 4362) of group A applications but only in 9% (368 of 4071) of group B applications (P = .0001). The frequency of conduction recovery was lower in group A than in group B (5.9% vs 25%; P = .001). Arrhythmia-free survival at 6 months trended higher in group A (38 of 42 [90%]) than in group B (32 of 42 [76%]; P = .07).
  
  
  CONCLUSIONS
  Automated ablation lesion annotation provides real-time feedback of RF ablation that may improve effective energy delivery.
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts. Electronic address: eanter@bidmc.harvard.edu.
authors.forename: Elad
authors.initials: E
authors.lastname: Anter
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Cory M
authors.initials: CM
authors.lastname: Tschabrunn
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Contreras-Valdes
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Alfred E
authors.initials: AE
authors.lastname: Buxton
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
mesh_terms: D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery*; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Acute reconnection; Atrial fibrillation; Catheter ablation; Pulmonary vein isolation; Recurrence