title: Amiodarone in restoration and maintenance of sinus rhythm in patients with chronic atrial fibrillation after unsuccessful direct-current cardioversion.
abstract: BACKGROUND
  When direct-current (DC) cardioversion is used, sinus rhythm can be restored, at least temporarily, in 80-90% of patients with atrial fibrillation. However, there is a small but significant group of patients with chronic atrial fibrillation in whom DC cardioversion has failed to restore sinus rhythm. The value of antiarrhythmic drug pretreatment before DC cardioversion is still controversial.
  
  
  OBJECTIVE
  The aim of our study was to assess (1) the effectiveness of repeat DC cardioversion in patients with chronic atrial fibrillation after pretreatment with amiodarone, and (2) the efficacy of amiodarone in maintaining sinus rhythm after repeat cardioversion.
  
  
  METHODS
  Forty-nine patients with chronic atrial fibrillation after ineffective DC cardioversion were included in the study. Repeat DC cardioversion was performed after loading with oral amiodarone, 10-15 mg/kg body weight/day for a period necessary to achieve the cumulative dose of over 6.0 g.
  
  
  RESULTS
  Spontaneous conversion to sinus rhythm during amiodarone pretreatment was achieved in 9 of 49 patients (18%). Direct-current cardioversion was performed in 39 patients and sinus rhythm was achieved in 23 of these patients (59%). Mean heart rate decreased from 95 beats/min before to 68 beats/min after DC cardioversion (p < 0.001). Systolic blood pressure significantly (p < 0.05) decreased from 126 +/- 23 to 108 +/- 25 mmHg. Complications occurring in four patients just after electroconversion were well tolerated and of short duration. After 12 months, 52% of patients maintained sinus rhythm on low dose (200 mg/day) amiodarone therapy.
  
  
  CONCLUSIONS
  Pretreatment with amiodarone and repeat DC cardioversion allows for restoration of sinus rhythm in about 65% of patients with chronic atrial fibrillation after first ineffective DC cardioversion. Direct-current cardioversion can be performed safely with the use of standard precautions in patients who are receiving amiodarone. At 12 months' follow-up, more than 50% of patients maintain sinus rhythm on low-dose amiodarone after successful repeat cardioversion.
authors.affiliation: Department of Cardiology, Medical Academy of Warsaw, Poland.
authors.forename: G
authors.initials: G
authors.lastname: Opolski
authors.forename: J
authors.initials: J
authors.lastname: Stanisławska
authors.forename: A
authors.initials: A
authors.lastname: Górecki
authors.forename: G
authors.initials: G
authors.lastname: Swiecicka
authors.forename: A
authors.initials: A
authors.lastname: Torbicki
authors.forename: T
authors.initials: T
authors.lastname: Kraska
mesh_terms: D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000628:therapy*; D016022:Case-Control Studies; D002908:Chronic Disease; D003131:Combined Modality Therapy; D004554:Electric Countershock; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011292:Premedication; D012008:Recurrence; D019233:Retreatment; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone