title: Relationship between electroanatomical voltage mapping characteristics and breakout site of ventricular activation in idiopathic ventricular tachyarrhythmia originating from the right ventricular outflow tract septum.
abstract: OBJECTIVE
  To assess the electrophysiological characteristics of the breakout site of ventricular activation using electroanatomical voltage mapping (EVM) and its relation to the optimal ablation site in idiopathic ventricular tachyarrhythmias originating from the outflow tract of the (RVOT) septum.
  
  
  METHODS
  Twenty-eight patients with symptomatic drug-refractory premature ventricular complexes (PVCs) and/or ventricular tachycardia (VT) originating from the RVOT septum and 5 control subjects with WPW syndrome were included. Low-voltage areas (LVAs) were defined as signal amplitudes between 0.1 and 1.5 mV. The borderline between the normal area and the LVA was defined as "border," and the distance from the LVA to the border (length of LVA) was measured.
  
  
  RESULTS
  In all 28 patients and control subjects, there was an LVA below the pulmonary valve. There was no significant difference in length of LVA between patients with idiopathic ventricular arrhythmias and control subjects (2.0 ± 0.6 vs. 1.9 ± 0.1 cm). In 19 of the 28 patients, the optimal ablation site was identical to the border area. In all 11 patients who had pre-potentials at the successful ablation site, there were two cases with polymorphic VT and/or ventricular fibrillation associated with PVCs. In these two cases, length of LVA was longer than in other patients (4.0 and 3.9 cm vs. 1.8 ± 0.5 cm (n = 26)), and the optimal ablation site was located at the border area.
  
  
  CONCLUSIONS
  The border area, including the LVA, tends to be the breakout site and/or origin of ventricular arrhythmias in idiopathic ventricular tachyarrhythmia originating from the RVOT septum.
authors: The First Department of Internal Medicine, Niigata University School of Medicine, 1-754 Asahi-machi-dori, Niigata, 951-8510, Japan. chimiri@med.niigata-u.ac.jp
authors: Hiroshi
authors: H
authors: Furushima
authors: Masaomi
authors: M
authors: Chinushi
authors: Kenichi
authors: K
authors: Iijima
authors: Daisuke
authors: D
authors: Izumi
authors: Yukio
authors: Y
authors: Hosaka
authors: Yoshifusa
authors: Y
authors: Aizawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000601:surgery*; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology; D054088:Ventricular Septum / Q000503:physiopathology*; D055815:Young Adult