title: Efficacy of amiodarone for preventing the recurrence of symptomatic paroxysmal and persistent atrial fibrillation after cardioversion.
abstract: BACKGROUND
  It has been previously reported that the efficacy of class I antiarrhythmics in preventing the recurrence of symptomatic paroxysmal and persistent atrial fibrillation (AF) is limited when AF lasts for 48 h or more. However, it is unclear whether the efficacy of amiodarone, a class III drug, is superior to class I antiarrhythmics in patients with long-lasting AF.
  
  
  RESULTS
  The relationship between the duration of tachycardia and the efficacy of amiodarone in preventing recurrence of tachycardia was examined in 55 patients (37 men, 18 women, mean age 68+/-9 years) to whom amiodarone was administered after electrical or pharmacological cardioversion for paroxysmal and persistent AF. In 26 patients, paroxysmal and persistent AF ceased within 48 h after onset (Group A), and in the other 29 patients, it ceased after 48 h (Group B). Patient characteristics and actuarial recurrence-free rates were compared between the 2 groups. The mean follow-up period was 30+/-11 months. No statistically significant difference between the groups was found in patient characteristics. Actuarial recurrence-free rates in Group A and B at 1, 3, 6, 9, and 12 months were 100%, 81%, 69%, 62%, and 54%, and 93%, 79%, 66%, 52%, and 48%, respectively (p=NS at 12 months). The period of maintenance of sinus rhythm was 14.7+/-3.2 months in group A and 13.3+/-3.3 months in group B (mean+/-SE, p=NS).
  
  
  CONCLUSIONS
  In the case of amiodarone, efficacy for maintaining sinus rhythm after cardioversion of AF was not biased by the duration of arrhythmia. This observation suggests amiodarone is effective in maintaining normal sinus rhythm after cardioversion, even in patients with long-lasting AF and electrical atrial remodeling.
authors.affiliation: Second Department of Internal Medicine, Iwate Medical University School of Medicine, Morioka, Japan. sym.koma@imu.ncvc.go.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Komatsu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tachibana
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: Mahito
authors.initials: M
authors.lastname: Ozawa
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Nakamura
authors.forename: Ken
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000009:adverse effects / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000517:prevention & control* / Q000628:therapy*; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D055502:Secondary Prevention; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone