title: Clinical and Electrocardiographic Characteristics of Electrical Storms Due to Monomorphic Ventricular Tachycardia Refractory to Intravenous Amiodarone.
abstract: BACKGROUND
  Few reports are available on the characteristics of electrical storms of ventricular tachycardia (VT storm) refractory to intravenous (IV) amiodarone.
  
  
  RESULTS
  IV-amiodarone was administered to 60 patients with ventricular tachyarrhythmia between 2007 and 2012. VT storms, defined as 3 or more episodes of VT within 24 h, occurred in 30 patients (68±12 years, 7 female), with 12 having ischemic and 18 non-ischemic heart disease. We compared the clinical and electrocardiographic characteristics of the patients with VT storms suppressed by IV-amiodarone (Effective group) to those of patients not affected by the treatment (Refractory group). IV-amiodarone could not control recurrence of VT in 9 patients (30%). The Refractory group comprised 5 patients with acute myocardial infarctions. Although there was no difference in the VT cycle length, the QRS duration of both the VT and premature ventricular contractions (PVCs) followed by VT was narrower in the Refractory group than in the Effective group (140±30 vs. 178±25 ms, P<0.01; 121±14 vs. 179±22 ms, P<0.01). In the Refractory group, additional administration of IV-mexiletine and/or Purkinje potential-guided catheter ablation was effective.
  
  
  CONCLUSIONS
  IV-amiodarone-refractory VT exhibited a relatively narrow QRS tachycardia. The narrow triggering PVCs, suggesting a Purkinje fiber origin, may be treated by additional IV-mexiletine and endocardial catheter ablation.
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Murata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyauchi
authors.forename: Meiso
authors.initials: M
authors.lastname: Hayashi
authors.forename: Yu-Ki
authors.initials: YK
authors.lastname: Iwasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Yodogawa
authors.forename: Akira
authors.initials: A
authors.lastname: Ueno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hayashi
authors.forename: Ippei
authors.initials: I
authors.lastname: Tsuboi
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Uetake
authors.forename: Kenta
authors.initials: K
authors.lastname: Takahashi
authors.forename: Teppei
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Maruyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Akutsu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Atarashi
authors.forename: Takao
authors.initials: T
authors.lastname: Katoh
authors.forename: Wataru
authors.initials: W
authors.lastname: Shimizu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone; D004351:Drug Resistance; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D017180:Tachycardia, Ventricular / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy
chemical_list: D000638:Amiodarone