title: Rapid mapping and differentiation in ventricular outflow tract arrhythmia using non-contact mapping.
abstract: OBJECTIVE
  Ventricular outflow tract arrhythmias (VOTAs) can be successfully treated by catheter ablation. However, it is sometimes difficult to differentiate the origin of VOTAs between the right ventricular outflow tract (RVOT) and the other sites, leading to a long fluoroscopy time and unnecessary radiofrequency applications. This study aimed to clarify distinguishable characteristics of the propagation pattern obtained from non-contact mapping (NCM) for VOTA ablation.
  
  
  METHODS
  Consecutive 45 patients with VOTAs who underwent catheter ablation using the NCM system were included in this study. We analyzed an isopotential map on three-dimensional geometry of the RVOT obtained from the virtual unipolar electrograms (VUEs) and assessed mapping data of the isopotential area with an initial negative VUE of -1 mV.
  
  
  RESULTS
  Successful ablation was achieved from the endocardial RVOT in 34 patients (RVOT group) and the non-RVOT in 11 (non-RVOT group). Major and minor axis diameters of the isopotential area did not significantly differ between the two groups. However, a ratio of major/minor axis diameter was greater in the RVOT group (1.9 ± 0.1 versus 1.3 ± 0.1; P < 0.001). In addition, the propagation velocity defined as an increase of the isopotential area per millisecond was significantly slower in the RVOT group (2.2 ± 0.4 versus 4.2 ± 0.7 mm2/ms; P = 0.02).
  
  
  CONCLUSIONS
  The isopotential area of VOTAs originating from the RVOT, as compared to the other sites, spread more elliptically and slowly. The propagation pattern obtained from NCM can provide useful information and efficient strategy for VOTA ablation.
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. adta4127@chiba-u.jp.
authors.forename: Kazuo
authors.identifier: http://orcid.org/0000-0002-1453-9037
authors.initials: K
authors.lastname: Miyazawa
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Marehiko
authors.initials: M
authors.lastname: Ueda
authors.affiliation: Department of Advanced Cardiovascular Therapeutics, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kondo
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Miyo
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishimura
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000465:Algorithms; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000601:surgery*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Catheter ablation; Non-contact mapping; Propagation pattern; Ventricular outflow tract arrhythmia