Pharmacological cardioversion of persistent atrial fibrillation with and without a history of drug-resistant paroxysmal atrial fibrillation.
BACKGROUND
Suppression by antiarrhythmic drugs of the maintenance mechanisms could convert persistent atrial fibrillation (AF) to sinus rhythm (SR). Whether a history of drug-resistant paroxysmal AF (PAF) would affect the outcome of pharmacological conversion of persistent AF by bepridil or in combination with aprindine was evaluated in the present study.


RESULTS
The study group comprised 51 consecutive patients (24 men, 61+/-8 years) undergoing pharmacological conversion of persistent AF lasting >1 month. Drug-resistant PAF was defined as AF and at least 2 ineffective antiarrhythmic drugs for suppression of AF recurrence. Fast Fourier transform analysis of fibrillation waves was used to measure fibrillation cycle length (FCL) from the peak frequency. Fifteen patients had a history of drug-resistant PAF (Group I), and the remaining 36 did not (Group II) before diagnosis of persistent AF. Ten patients (67%) in Group I and 26 patients (72%) in Group II were restored to SR by bepridil alone or in combination with aprindine after 29+/-15 days of drug administration. Before conversion to SR, bepridil increased the FCL more in Group II than in Group I. During a 12-month follow-up period, 4 of 10 patients in Group I and 2 of 26 patients in Group II (p<0.01) had recurrence of persistent AF with bepridil alone or in combination with aprindine.


CONCLUSIONS
A history of drug-resistant PAF does not affect the efficacy of pharmacological conversion by bepridil or in combination with aprindine. However, recurrence of AF was significantly higher in patients with such a history.
Fujiki
Akira
A
The Second Department of Internal Medicine, Faculty of Medicine, University of Toyama, Japan. fujiki@med.u-toyama.ac.jp
Sakamoto
Tamotsu
T
Iwamoto
Jotaro
J
Nishida
Kunihiro
K
Nagasawa
Hidehiko
H
Mizumaki
Koichi
K
Inoue
Hiroshi
H
D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001073:Aprindine / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000628:therapy*; D015764:Bepridil / Q000008:administration & dosage*; D004338:Drug Combinations; D004351:Drug Resistance / Q000187:drug effects*; D004554:Electric Countershock; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged
D000889:Anti-Arrhythmia Agents; D004338:Drug Combinations; D001073:Aprindine; D015764:Bepridil