[Relationship between duration of arrhythmia and subsequent preventive effect of disopyramide after cardioversion in patients with symptomatic paroxysmal and persistent atrial fibrillation].
OBJECTIVE
The relationship between the duration of arrhythmia and the subsequent long-term efficacy of disopyramide in preventing atrial fibrillation was investigated in patients with symptomatic paroxysmal and persistent atrial fibrillation.


METHODS
A total of 60 patients (39 men, 21 women, mean age 65 +/- 11 years) were given disopyramide (300 mg/day) after electrical and pharmacological cardioversion based on American Heart Association Task Force on Practice Guidelines. The patients were divided into two types based on the duration of atrial fibrillation: conversion within 48 hr (group A, n = 35) and more than 48 hr (group B, n = 25) after the episode. Mean follow-up period was 47.1 +/- 28.7 months.


RESULTS
Patient characteristics showed no statistically significant difference between groups A and B. The actuarial rates of maintenance of sinus rhythm at 1, 3, 6, 12, 18 and 24 months were 88.6%, 77.1%, 57.1%, 48.6%, 42.9% and 37.1%, respectively, in group A, and 72.0%, 44.0%, 28.0%, 16.0%, 12.0% and 8.0%, respectively, in group B. There was a significant difference in the rate at 24 months between groups A and B (p < 0.05). The periods for maintenance of sinus rhythm in groups A and B were 20.9 +/- 3.9 and 6.7 +/- 2.1 months, respectively, with a significant difference between groups A and B (p < 0.01).


CONCLUSIONS
The efficacy of disopyramide in preventing the recurrence of atrial fibrillation varies with the duration of the previous episode. These results demonstrate that it is important to convert to normal sinus rhythm earlier to prevent the recurrence of atrial fibrillation in the long term.
Komatsu
Takashi
T
Division of Cardiology, Department of Internal Medicine, Iwate Prefectural Iwai Hospital, Maeda 13, Yamanome, Ichinoseki, Iwate 021-8533.
Yomogida
Kunihiko
K
Nakamura
Shin
S
Suzuki
Osamu
O
Horiuchi
Daisuke
D
Kameda
Kunihiko
K
Tomita
Hirofumi
H
Abe
Naoki
N
Owada
Shingen
S
Oikawa
Koichi
K
Okumura
Ken
K
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000628:therapy; D001281:Atrial Fibrillation / Q000150:complications / Q000517:prevention & control* / Q000628:therapy*; D004206:Disopyramide / Q000627:therapeutic use*; D004554:Electric Countershock; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D055502:Secondary Prevention; D013997:Time Factors
D000889:Anti-Arrhythmia Agents; D004206:Disopyramide