title: The effects of pure potassium channel blocker nifekalant and sodium channel blocker mexiletine on malignant ventricular tachyarrhythmias.
abstract: Patients with repetitive ventricular tachyarrhythmias - so-called electrical storm - frequently require antiarrhythmic drugs. Amiodarone is widely used for the treatment of electrical storm but is ineffective in some patients. Therefore, we investigated the efficacy of stepwise administration of nifekalant, a pure potassium channel blocker, and mexiletine for electrical storm.
  
  
  
  This study included 44 patients with repetitive ventricular tachyarrhythmias who received stepwise therapy with nifekalant and mexiletine for electrical storm. Nifekalant was initially administered, and mexiletine was subsequently added if nifekalant failed to control ventricular tachyarrhythmias.
  
  
  
  Nifekalant completely suppressed recurrences of ventricular arrhythmias in 28 patients (64%), including 6 patients in whom oral amiodarone failed to control arrhythmias. In 9 of 16 patients in whom nifekalant was partially effective but failed to suppress ventricular arrhythmias, mexiletine was added. The addition of mexiletine prevented recurrences of ventricular tachyarrhythmias in 5 of these 9 patients (56%). There was no death associated with electrical storm. In total, the stepwise treatment with nifekalant and mexiletine was effective in preventing ventricular tachyarrhythmias in 33 of 44 patients (75%). There was no difference in cycle length of the ventricular tachycardia, QRS interval, QT interval, or left ventricular ejection fraction between patients who responded to antiarrhythmic drugs and those who did not. During follow-up, 8 patients had repetitive ventricular tachyarrhythmia recurrences, and the stepwise treatment was effective in 6 of these 8 patients (75%).
  
  
  
  The stepwise treatment with nifekalant and mexiletine was highly effective in the suppression of electrical storm.
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan. Electronic address: tallmoca@mte.biglobe.ne.jp.
authors.forename: Sou
authors.initials: S
authors.lastname: Otuki
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Hasegawa
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Goro
authors.initials: G
authors.lastname: Katsuumi
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Nobue
authors.initials: N
authors.lastname: Yagihara
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iijima
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Sato
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furushima
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Yoshifusa
authors.initials: Y
authors.lastname: Aizawa
authors.affiliation: Department of Cardiovascular Biology and Medicine, Niigata University School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Minamino
mesh_terms: D000284:Administration, Oral; D004569:Electroencephalography / Q000187:drug effects*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008801:Mexiletine / Q000008:administration & dosage*; D026902:Potassium Channel Blockers / Q000008:administration & dosage*; D015995:Prevalence; D011744:Pyrimidinones / Q000008:administration & dosage*; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D026941:Sodium Channel Blockers / Q000008:administration & dosage*; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality*; D016896:Treatment Outcome
chemical_list: D026902:Potassium Channel Blockers; D011744:Pyrimidinones; D026941:Sodium Channel Blockers; D008801:Mexiletine; C076259:nifekalant
keywords: Arrhythmias; Drugs; Electrical storm; Heart diseases; Sudden death