title: Influence of patient factors and ablative technologies on outcomes of radiofrequency ablation of intra-atrial re-entrant tachycardia in patients with congenital heart disease.
abstract: OBJECTIVE
  The goal of this study was to identify factors associated with radiofrequency catheter ablation (RFCA) outcomes of intra-atrial re-entrant tachycardia (IART).
  
  
  BACKGROUND
  Radiofrequency catheter ablation of IART is difficult. The influence of patient and procedural factors and novel technologies on outcomes is unknown.
  
  
  METHODS
  Acute and chronic RFCA outcomes were studied in patients with congenital heart disease and IART. Clinical status was measured using a multiaxis severity score. Multivariate analyses identified associations of clinical, procedural and technological factors with outcomes.
  
  
  RESULTS
  A total of 177 procedures were performed in 134 patients; 139 procedures (79%) resulted in RFCA of > or =1 IART circuit and 117 (66%) in RFCA of all targeted circuits. Multivariate analysis associated acute success with irrigated ablation and absence of atrial fibrillation. Twenty-two complications were noted, nine related to vascular access. Electroanatomic mapping failed to decrease procedure or fluoroscopy time. Improvement in clinical status occurred in most patients (severity score preablation: 6.2 +/- 1.6, postablation: 3.0 +/- 2.3, p < 0.0001). At mean follow-up of 25 +/- 11 months, 42% of patients had IART recurrence and 28% required cardioversion. Six deaths occurred (1.8%/patient-year), and two patients underwent transplant. Chronic outcomes were associated with higher right atrial saturations, use of electroanatomic mapping, fewer IART circuits encountered and acute procedural success.
  
  
  CONCLUSIONS
  Improvement of acute RFCA outcomes was contemporaneous with introduction of novel technologies. Intra-atrial re-entrant tachycardia recurrence was common, and no effect on mortality was discerned, but most patients had effective palliation of symptoms. Chronic outcome predictors included the underlying disease severity, application of novel technologies and successful ablation of all targeted arrhythmia circuits.
authors.affiliation: Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA. john.triedman@tch.harvard.edu
authors.forename: John K
authors.initials: JK
authors.lastname: Triedman
authors.forename: Mark E
authors.initials: ME
authors.lastname: Alexander
authors.forename: Barry A
authors.initials: BA
authors.lastname: Love
authors.forename: Kathryn K
authors.initials: KK
authors.lastname: Collins
authors.forename: Charles I
authors.initials: CI
authors.lastname: Berul
authors.forename: Laura M
authors.initials: LM
authors.lastname: Bevilacqua
authors.forename: Edward P
authors.initials: EP
authors.lastname: Walsh
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods*; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000145:classification / Q000150:complications* / Q000601:surgery; D006801:Humans; D013617:Tachycardia, Supraventricular / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome