Bepridil prevents paroxysmal atrial fibrillation by a class III antiarrhythmic drug effect.
BACKGROUND
[corrected] Bepridil, a multiple ion-channel blocker, has been reported to prevent paroxysmal atrial fibrillation (PAF). The f-f interval of PAF during treatment with bepridil versus class Ic antiarrhythmic drugs was compared.


METHODS
Fifty-two patients with PAF were randomized to bepridil, 200 mg/day (n = 14) versus flecainide, 100 to 200 mg/day (n = 15) or pilsicainide, 75 to 150 mg/day (n = 23). The drug was considered effective when symptomatic episodes of PAF were decreased to < 50% during a follow-up of 2 to 6 months. The f-f interval was measured in 12-lead ECGs of initial PAF episodes.


RESULTS
Bepridil and Ic were effective in 10 of 14 (71.4%) and 24 of 38 patients (63.2%), respectively (ns). In the Ic group, the f-f interval was longer in successfully (114 +/- 48 ms) than in unsuccessfully (68 +/- 25 ms) treated patients (P = 0.002). In the bepridil group, the f-f interval was shorter in successfully (84 +/- 27 ms) than unsuccessfully (155 +/- 68 ms) treated patients (P = 0.015). When comparing unsuccessfully treated patients, the f-f interval in the bepridil group was significantly longer than in the Ic group (P = 0.007).


CONCLUSIONS
Bepridil was as effective as Ic drugs in the prevention of PAF. Because it was more effective in smaller (functional) than larger (anatomical) reentrant circuits, the effect of bepridil was considered to be mainly attributable to a class III antiarrhythmic action.
Yoshida
Toru
T
Department of Internal Medicine, Kitasato University School of Medicine, 1-15 Kitasato 1 Sagamihara, 228-8555 Japan. yoshidat@med.kitasato-u.ac.jp
Niwano
Shinichi
S
Inuo
Kimiatsu
K
Saito
Junko
J
Kojima
Jisho
J
Ikeda-Murakami
Kazuko
K
Hara
Hideyuki
H
Izumi
Tohru
T
D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000517:prevention & control*; D015764:Bepridil / Q000627:therapeutic use*; D004562:Electrocardiography; D005260:Female; D005424:Flecainide / Q000627:therapeutic use; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged
D000889:Anti-Arrhythmia Agents; D015764:Bepridil; D008012:Lidocaine; C042288:pilsicainide; D005424:Flecainide