title: Malignant entity of idiopathic ventricular fibrillation and polymorphic ventricular tachycardia initiated by premature extrasystoles originating from the right ventricular outflow tract.
abstract: OBJECTIVE
  The aim of this study was to assess the clinical characteristics and the efficacy of radiofrequency catheter ablation (RFCA) for idiopathic ventricular fibrillation (VF) and/or polymorphic ventricular tachycardia initiated by ventricular extrasystoles originating from the right ventricular outflow tract (RVOT).
  
  
  BACKGROUND
  Ventricular fibrillation and/or polymorphic ventricular tachycardia are occasionally initiated by ventricular extrasystoles originating from the RVOT in patients without structural heart disease.
  
  
  METHODS
  Among 101 patients without structural heart disease in whom RFCA was conducted for idiopathic ventricular tachyarrhythmias arising from the RVOT, we examined the clinical characteristics and the efficacy of RFCA in 16 patients with spontaneous VF and/or polymorphic ventricular tachycardia initiated by the ventricular extrasystoles originating from the RVOT.
  
  
  RESULTS
  Among 16 patients, spontaneous episodes of VF were documented in 5 patients, and 11 patients had prior episodes of syncope. Holter recordings showed frequent isolated ventricular extrasystoles with the same morphology as that of initiating ventricular extrasystoles, and non-sustained polymorphic ventricular tachycardia with short cycle length (mean of 245 +/- 28 ms) in all 16 patients. Radiofrequency catheter ablation by targeting the initiating ventricular extrasystoles eliminated episodes of syncope, VF, and cardiac arrest in all patients during follow-up periods of 54 +/- 39 months.
  
  
  CONCLUSIONS
  Our data suggest that the malignant entity of idiopathic VF and/or polymorphic ventricular tachycardia was occasionally present in patients with idiopathic ventricular arrhythmias arising from the RVOT. Radiofrequency catheter ablation was effective as a treatment option for this entity.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Research Institute, National Cardiovascular Center, Suita, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Noda
authors.forename: Wataru
authors.initials: W
authors.lastname: Shimizu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Taguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aiba
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Satomi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Kurita
authors.forename: Naohiko
authors.initials: N
authors.lastname: Aihara
authors.forename: Shiro
authors.initials: S
authors.lastname: Kamakura
mesh_terms: D000328:Adult; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D018879:Ventricular Premature Complexes / Q000150:complications* / Q000503:physiopathology