title: Estimation of the origin of ventricular outflow tract arrhythmia using synthesized right-sided chest leads.
abstract: OBJECTIVE
  For successful ablation of ventricular outflow tract arrhythmia, estimation of its origin prior to the procedure can be useful. Morphology and lead placement in the right thoracic area may be useful for this purpose. Electrocardiography using synthesized right-sided chest leads (Syn-V3R, Syn-V4R, and Syn-V5R) is performed using standard leads without any additional leads. This study evaluated the usefulness of synthesized right-sided chest leads in estimating the origin of ventricular outflow tract arrhythmia.
  
  
  RESULTS
  This retrospective study included 63 patients in whom successful ablation of ventricular outflow tract arrhythmia was performed. Numbers of arrhythmias originating from the left ventricle, the septum of the right ventricle, and the free wall of the right ventricle were 11, 40, and 13, respectively. In one patient, two different left ventricular outflow tract origins were found. Electrocardiographic recordings from right-sided chest leads were divided into three types as follows: those in which an R > S concordance, a transitional zone, or an R < S concordance were detected. In all left arrhythmia cases, R > S concordance was observed. A transitional zone was evident in 34 of 40 cases of right ventricular outflow tract arrhythmia originating in the ventricular septum, and an R < S concordance was observed in 6 of the 40 cases. However, an R < S concordance was found in all cases of right ventricular outflow tract arrhythmia originating in the free wall.
  
  
  CONCLUSIONS
  Synthesized right-sided chest lead electrocardiography may be useful for estimating the origin of ventricular outflow tract arrhythmia.
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan masahiromasap@yahoo.co.jp.
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: Marehiko
authors.initials: M
authors.lastname: Ueda
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: Takatsugu
authors.initials: T
authors.lastname: Kajiyama
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Hashiguchi
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kanaeda
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, 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: Yasunori
authors.initials: Y
authors.lastname: Hiranuma
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: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Catheter ablation; Outflow tract tachycardia; Synthesized electrocardiography