title: Role of catheter-induced mechanical trauma in localization of target sites of radiofrequency ablation in automatic atrial tachycardia.
abstract: OBJECTIVE
  We compared the efficacy of two different mapping techniques in identifying the ablation site for atrial tachycardia. Moreover, we evaluated the additive positive predictive value of mechanical interruption of atrial tachycardia to reduce the number of ineffective radiofrequency applications.
  
  
  BACKGROUND
  Radiofrequency catheter ablation has been suggested as a highly effective technique to treat drug-resistant atrial tachycardia. However, irrespective of the mapping technique utilized, success was most often achieved with a large number of radiofrequency applications.
  
  
  METHODS
  Forty-five patients with atrial tachycardia underwent radiofrequency catheter ablation. Mapping techniques included identification of earliest atrial activation and pace-mapping concordant sequence.
  
  
  RESULTS
  Atrial tachycardia was successfully treated in 42 (93.3%) of 45 patients with a mean of 3.9 radiofrequency pulses/patient. An interval between the onset of the intracavitary atrial deflection and the onset of the P wave during atrial tachycardia (AP interval) > or = 30 ms (p < 0.001) and pace-mapping concordant sequence (p = 0.01) were all significant predictors of outcome. An AP interval > or = 30 ms and a pace-mapping concordant sequence were highly sensitive (92.8%, 95% confidence interval [CI] 80.5% to 98.5%; 85.7%, 95% CI 71.5% to 94.6%, respectively) but less specific (47.8%, 95% CI 37.9% to 58.2%, 36.8%, 95% CI 27.6% to 47.2%, respectively) in identifying the site of ablation. By using atrial tachycardia mechanical interruption combined with the AP interval >30 ms or the pace-mapping concordant sequence, we obtained a specifically of 76.5% (95% CI 66.4% to 84.0%) and 73.5% (95% CI 63.2% to 81.4%), respectively, and a positive predictive value of 49.2% and 44.6%, respectively.
  
  
  CONCLUSIONS
  An AP interval > or = 30 ms and a pace-mapping concordant sequence were reliable mapping features for predicting the outcome of the ablation procedure. Mechanical interruption of atrial tachycardia improved the specificity and positive predictive value of these two mapping techniques.
authors.affiliation: Department of Cardiology and Cardiac Surgery, Medical School, Federico II University, Naples, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Pappone
authors.forename: G
authors.initials: G
authors.lastname: Stabile
authors.forename: A
authors.initials: A
authors.lastname: De Simone
authors.forename: G
authors.initials: G
authors.lastname: Senatore
authors.forename: P
authors.initials: P
authors.lastname: Turco
authors.forename: M
authors.initials: M
authors.lastname: Damiano
authors.forename: D
authors.initials: D
authors.lastname: Iorio
authors.forename: N
authors.initials: N
authors.lastname: Spampinato
authors.forename: M
authors.initials: M
authors.lastname: Chiariello
mesh_terms: D000293:Adolescent; D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013617:Tachycardia, Supraventricular / Q000503:physiopathology / Q000601:surgery*