title: Drug-induced changes in fibrillation cycle length and organization index can predict chemical cardioversion of long-lasting atrial fibrillation with bepridil alone or in combination with aprindine.
abstract: BACKGROUND
  The aim of this study was to investigate whether drug-induced changes in fibrillation wave characteristics can predict pharmacological conversion of long lasting persistent atrial fibrillation (AF).
  
  
  RESULTS
  The study group comprised 23 consecutive patients with AF lasting > or =1 month. Patients first received bepridil (200 mg/day) for 2-4 weeks. When sinus rhythm was not restored with bepridil, oral aprindine (40 or 60 mg/day) was added to bepridil. Fast Fourier transform analysis of fibrillation waves using lead V1 was performed to calculate the fibrillation cycle length (FCL). The spectral areas were measured and the maximum area divided by the total area was termed the fibrillation organization index (FOI). Sinus rhythm was restored in 16 of 23 patients (70%); 8 of these 16 patients received only bepridil (Group I) and the other 8 responders received bepridil and aprindine (Group II). In Group I bepridil increased both FCL (p<0.001) and FOI (p<0.01) and terminated AF after 20+/-12 days. In Group II bepridil increased FCL (p<0.001), but did not change FOI. The addition of aprindine terminated AF in association with an increase in both FCL (p<0.005) and FOI (p<0.005) within 19+/-8 days. In the remaining 7 patients who did not have restoration of sinus rhythm, bepridil increased both FCL and FOI significantly, but less than in Group I, and the addition of aprindine did not further increase either of them. Chemical cardioversion of AF occurred in all patients with FCL > or =190 ms and FOI > or =45% after drug administration.
  
  
  CONCLUSIONS
  Bepridil alone or in combination with aprindine converted long lasting persistent AF in association with an increase in both FCL and FOI. The combination of FCL and FOI after drug administration is helpful in predicting chemical cardioversion of persistent AF.
authors.affiliation: The Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Toyama, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Fujiki
authors.forename: Masao
authors.initials: M
authors.lastname: Sakabe
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nishida
authors.forename: Masataka
authors.initials: M
authors.lastname: Sugao
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsuneda
authors.forename: Jotaro
authors.initials: J
authors.lastname: Iwamoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Mizumaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001073:Aprindine / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology*; D015764:Bepridil / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D001073:Aprindine; D015764:Bepridil