title: Inducible atrial tachycardias with multiple circuits in a stepwise approach are associated with increased episodes of atrial tachycardias after catheter ablation.
abstract: BACKGROUND
  Atrial tachycardia (AT) is commonly observed during catheter ablation (CA) in patients with atrial fibrillation (AF) undergoing a stepwise extensive CA. In this study, we examined the hypothesis that the presence of multiple inducible ATs (multiple-ATs), which allow for latent multiple reentrant circuits, might increase the potential for following AT episodes after CA.
  
  
  RESULTS
  The study population consisted of 347 consecutive AF patients undergoing CA with a stepwise approach. A total of 366 ATs (tricuspid isthmus dependent, 101; mitral annulus, 62; septal, 26; roof dependent, 22; left atrial anterior wall, 13; upper loop, 8; surrounding the left pulmonary veins, 6; surrounding the right pulmonary veins, 6; left atrial appendage, 4; and Cs ostium, 3) occurring during the CA were found in 216 (62.2%) of 347 patients. Multiple-ATs (≥2) during the CA were observed in 93 (26.8%) of 347 patients. The incidence of AT episodes significantly increased as the number of inducible ATs increased (no AT, 7.8%; single AT, 13.7%; and multiple-ATs, 24.2%; P < .001), and multiple-ATs were an independent risk factor for AT episodes (3.07 [1.39-6.78]; P = .005). The impact of the multiple-ATs on the AT episodes was pronounced especially in the patients with coinducible residual AF (with coresidual AF vs without coresidual AF, 8.1% vs 47.7%; P < .001).
  
  
  CONCLUSIONS
  The presence of an atrial substrate allowing for multiple-ATs was associated with increased AT episodes during follow-up.
authors.affiliation: Caridiovascular Division, Shiroyama Hospital, Habikino City, Osaka, Japan. kurotobi-circ@umin.ac.jp
authors.forename: Toshiya
authors.initials: T
authors.lastname: Kurotobi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Shimada
authors.forename: Naoto
authors.initials: N
authors.lastname: Kino
authors.forename: Koichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Kimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okuyama
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Nanto
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D016009:Chi-Square Distribution; D017548:Echocardiography, Transesophageal; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013612:Tachycardia, Ectopic Atrial / Q000209:etiology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome