title: Electrical storm in idiopathic ventricular fibrillation is associated with early repolarization.
abstract: OBJECTIVE
  This study sought to characterize patients with idiopathic ventricular fibrillation (IVF) who develop electrical storms.
  
  
  BACKGROUND
  Some IVF patients develop ventricular fibrillation (VF) storms, but the characteristics of these patients are poorly known.
  
  
  METHODS
  Ninety-one IVF patients (86% male) were selected after the exclusion of structural heart diseases, primary electrical diseases, and coronary spasm. Electrocardiogram features were compared between the patients with and without electrical storms. A VF storm was defined as VF occurring ≥3 times in 24 h and J waves >0.1 mV above the isoelectric line in contiguous leads.
  
  
  RESULTS
  Fourteen (15.4%) patients had VF storms occurring out-of-hospital at night or in the early morning. J waves were more closely associated with VF storms compared to patients without VF storms: 92.9% versus 36.4% (p < 0.0001). VF storms were controlled by intravenous isoproterenol, which attenuated the J-wave amplitude. After the subsidence of VF storms, the J waves decreased to the nondiagnostic level during the entire follow-up period. Implantable cardioverter-defibrillator therapy was administered to all patients during follow-up. Quinidine therapy was limited, but the patients on disopyramide (n = 3), bepridil (n = 1), or isoprenaline (n = 1) were free from VF recurrence, while VF recurred in 5 of the 9 patients who were not given antiarrhythmic drugs.
  
  
  CONCLUSIONS
  The VF storms in the IVF patients were highly associated with J waves that showed augmentation prior to the VF onset. Isoproterenol was effective in controlling VF and attenuated the J waves, which diminished to below the diagnostic level during follow-up. VF recurred in patients followed up without antiarrhythmic agents.
authors.affiliation: Tachikawa Medical Center, Nagaoka, Japan. aizaways@med.niigata-u.ac.jp
authors.forename: Yoshifusa
authors.initials: Y
authors.lastname: Aizawa
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.forename: Kanae
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Nobu
authors.initials: N
authors.lastname: Naiki
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
authors.forename: Shogo
authors.initials: S
authors.lastname: Ito
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Imaizumi
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Aizawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Takatsuki
authors.forename: Kunitake
authors.initials: K
authors.lastname: Joo
authors.forename: Masahito
authors.initials: M
authors.lastname: Sato
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ebe
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hosaka
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000293:Adolescent; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D055724:Electrophysiological Phenomena / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007545:Isoproterenol / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000503:physiopathology* / Q000517:prevention & control / Q000628:therapy; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents; D007545:Isoproterenol
keywords: ECG; IVF; VF; early repolarization; electrical storm; electrocardiogram; idiopathic ventricular fibrillation; isoproterenol; ventricular fibrillation