title: Strategies for reversing shock-resistant ventricular fibrillation.
abstract: OBJECTIVE
  Shock-resistant ventricular fibrillation is defined as ventricular fibrillation persisting after three defibrillation attempts. In approximately 10 to 25% of all cardiac arrests, shock-resistant ventricular fibrillation develops, and 87 to 98% of these patients die.
  
  
  RESULTS
  In the treatment of shock-resistant ventricular fibrillation, defibrillation using biphasic waveforms is considered as an intervention of choice. Intravenous amiodarone is also acceptable, safe, and useful, based on evidence from two randomized clinical trials. Intravenous vasopressin is acceptable and probably safe and useful, but the evidence supporting this recommendation is coming from a small, randomized clinical trial. Procainamide is acceptable but not recommended. In the presence of acute myocardial infarction and recurrent ventricular fibrillation, if all other therapies fail, beta-blockers can be considered. Magnesium, lidocaine, and bretylium are not recommended in the treatment of shock-resistant ventricular fibrillation.
  
  
  CONCLUSIONS
  Biphasic defibrillation and intravenous amiodarone are useful in shock-resistant ventricular fibrillation.
authors.affiliation: Division of Cardiology, St Michaels's Hospital, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Sarkozy
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001949:Bretylium Compounds / Q000627:therapeutic use; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004554:Electric Countershock / Q000379:methods*; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008012:Lidocaine / Q000627:therapeutic use; D008274:Magnesium / Q000627:therapeutic use; D011342:Procainamide / Q000627:therapeutic use; D014662:Vasoconstrictor Agents / Q000627:therapeutic use; D014667:Vasopressins / Q000627:therapeutic use; D014693:Ventricular Fibrillation / Q000150:complications / Q000628:therapy*
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D001949:Bretylium Compounds; D014662:Vasoconstrictor Agents; D014667:Vasopressins; D008012:Lidocaine; D008274:Magnesium; D011342:Procainamide; D000638:Amiodarone; C045166:bretylium