title: Multiple Intercostal Space Electrocardiogram Allows Accurate Localization of Outflow Tract Ventricular Arrhythmia Origin.
abstract: BACKGROUND
  Multiple intercostal recordings were supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate electrocardiogram (ECG) criterion for differentiating between left and right OT-VA origins.
  
  
  METHODS
  We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular OT (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10). Superior and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, transition zone (TZ) index, R/S amplitude ratio, and R-wave duration ratio were measured in the regular, superior, and inferior precordial leads.
  
  
  RESULTS
  The combined TZ index, TZ index inferior was significantly smaller, while the V2 inferior transition ratio was significantly larger for ACC origins than RVOT origins (P < 0.05). The area under the curve for the combined TZ index by a receiver operating characteristic analysis was 0.974, which was significantly larger than other parameters. A cutoff value ≤0.25 predicted an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0.
  
  
  CONCLUSIONS
  The combined TZ index outperformed other ECG criteria to differentiate left from right OT-VA origins.
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Yu-He
authors.initials: YH
authors.lastname: Jia
authors.affiliation: Department of Cardiology, Beijing Jishuitan Hospital, Beijing, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Ren
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Pi-Hua
authors.initials: PH
authors.lastname: Fang
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Gong-Bu
authors.initials: GB
authors.lastname: Zhou
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: He
authors.affiliation: Cardiac Arrhythmia Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: aortic sinus cusp; electrocardiogram; idiopathic ventricular arrhythmia; multiple intercostal space recording; right ventricular outflow tract; transitional zone