title: Atrial fibrillation in patients with permanent VVI pacemakers: risk factors for atrial fibrillation.
abstract: OBJECTIVE
  Atrial fibrillation (AF) does not only deteriorate the cardiac function and increases the thromboembolic risk but also triggers rapid and irregular ventricular rhythm in patients with atrial synchronous pacing. However, the risk factors for the development of AF in patients with pacemakers are not clearly determined yet. The present study was designed to determine the risk factors for AF in patients with VVI pacemakers.
  
  
  METHODS
  This study included 80 patients (41 sick sinus syndrome, 39 AV block) who were followed for more than 6 months or developed AF regardless of the duration of follow-up after implantation of VVI pacemakers. Patients were divided into two groups according to whether or not AF developed during follow-up (mean: 25.7 +/- 2.5 months): group A developed AF and group B did not. The underlying arrhythmias, cardiovascular risk factors, left atrial size, characteristics of P wave were compared between the two groups.
  
  
  RESULTS
  The mean age of the patients was 58.9 +/- 11.4 years and 28 (35%) were male. AF developed in 13 (16.3%) of 80 patients with VVI pacemakers. Sick sinus syndrome (SSS) as an underlying arrhythmia was significantly more frequent in group A than group B (84.6% vs. 44.8%, p < 0.01). P wave width was greater in group A (127.6 +/- 24.8 ms) than in group B (110.7 +/- 17 ms) (p < 0.05). There was, however, no significant difference in cardiovascular risk factors, left atrial size, P wave axis and amplitude between the two groups.
  
  
  CONCLUSIONS
  These results suggest that sinus node dysfunction and intra-atrial conduction delay may be the risk factors for AF in patients with VVI pacemakers. Further studies are needed to determine how sick sinus syndrome and intra-atrial conduction delay increase the risk for AF in patients with VVI pacemakers.
authors.affiliation: Department of Internal Medicine, Chonnam University Hospital, Kwangju, Korea.
authors.forename: J G
authors.initials: JG
authors.lastname: Cho
authors.forename: Y H
authors.initials: YH
authors.lastname: Jeong
authors.forename: I J
authors.initials: IJ
authors.lastname: Cho
authors.forename: Y G
authors.initials: YG
authors.lastname: Ahn
authors.forename: K S
authors.initials: KS
authors.lastname: Cha
authors.forename: J P
authors.initials: JP
authors.lastname: Seo
authors.forename: J H
authors.initials: JH
authors.lastname: Park
authors.forename: M H
authors.initials: MH
authors.lastname: Jeong
authors.forename: J C
authors.initials: JC
authors.lastname: Park
authors.forename: J C
authors.initials: JC
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000628:therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D012307:Risk Factors; D012804:Sick Sinus Syndrome / Q000628:therapy; D014463:Ultrasonography