title: [Severe ibutilide-induced arrhythmia in patients with heart failure].
abstract: BACKGROUND
  Ibutilide is a novel class III antiarrhythmic agent used for the termination of atrial flutter and atrial fibrillation. It mainly affects membrane potassium currents (IKr) and prolongs the cardiac action potential. This effect is reflected as QT-interval prolongation in the ECG. Drugs that affect IKr-currents are known to cause malignant ventricular arrhythmia.
  
  
  METHODS
  We report three patients with heart failure where ibutilide triggered malignant ventricular arrhythmias (sustained torsades de pointes).
  
  
  RESULTS
  All patients experienced dramatic haemodynamic deterioration. One patient died because of sustained arrhythmia. Mode of action for ibutilide is described. Precautions that should be observed when using ibutilide are outlined.
  
  
  CONCLUSIONS
  Ibutilide is contraindicated in patients with heart failure and should be used with caution in patients with ischaemic heart disease or previous myocardial infarction. Ibutilide-induced ventricular arrhythmias may be particularly difficult to treat in patients with heart failure.
authors.affiliation: Medisinsk avdeling Statens legemiddelverk Sven Oftedals vei 6 0950 Oslo.
authors.forename: P
authors.initials: P
authors.lastname: Harg
authors.forename: S
authors.initials: S
authors.lastname: Madsen
authors.forename: J P
authors.initials: JP
authors.lastname: Amlie
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D000075202:Contraindications; D004359:Drug Therapy, Combination; D017809:Fatal Outcome; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013449:Sulfonamides / Q000009:adverse effects*; D016171:Torsades de Pointes / Q000139:chemically induced*
chemical_list: D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide