title: Clinical comparison of ibutilide and propafenone for converting atrial flutter.
abstract: OBJECTIVE
  To evaluate the efficacy and safety of intravenous ibutilide and propafenone for immediate treatment of atrial flutter.
  
  
  METHODS
  Forty patients with atrial flutter with an arrhythmia duration of three hours to 90 days were randomized to receive up to two 10-minute infusions of ibutilide (1 and 1 mg) or propafenone (70 and 70 mg) with a 10-minute interval.
  
  
  RESULTS
  Ibutilide was superior to propafenone for treating atrial flutter (90% vs. 30%, p < 0.01). The median conversion time in the ibutilide group was 11 min (the 25th and 75th percentile was 10 and 45 min), and the median conversion time in the propafenone group was 35 min (range 20-55 min). In all patients, the duration of arrhythmia before treatment was a predictor of arrhythmia termination, although this was more obvious in the group that received ibutilide. Conversion of atrial flutter by ibutilide was characterized mainly by increased cycle length variability. Bradycardia (2/20) and hypotension (4/20) were more common side effects with propafenone. Of 20 patients given ibutilide, 8 (40%) who developed monomorphic ventricular extrasystoles or repetitive atrial flutter with aberrant conduction tachycardia, no one required any specific treatment except for the interruption of ibutilide infusion.
  
  
  CONCLUSIONS
  Ibutilide is highly effective for rapidly terminating atrial flutter. This new class III drug, under monitored conditions, is a potential alternative to currently available cardioversion options.
authors.affiliation: Electrophysiology Group, Department of Cardiology, People's Hospital, Peking University, Xi Zhi Men Nan Da Jie 11, Beijing, 100044, People's Republic of China. sunjianling2000@yahoo.com
authors.forename: Jian-Ling
authors.initials: JL
authors.lastname: Sun
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Guo
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.forename: Hai-Cheng
authors.initials: HC
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001282:Atrial Flutter / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011405:Propafenone / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D011446:Prospective Studies; D013449:Sulfonamides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide; D011405:Propafenone