title: Improvement of P-wave dispersion is associated with a lower incidence of atrial fibrillation after cardiac resynchronization therapy.
abstract: BACKGROUND
  P-wave dispersion (PWD) is a useful predictor of paroxysmal atrial fibrillation (AF). The effect of cardiac resynchronization therapy (CRT) on PWD and the prognostic implications of the improvement in PWD remain undefined. The aim of the study was to explore the clinical significance of the improvement of PWD after CRT.
  
  
  METHODS
  Electrocardiographic studies were performed before and three months after CRT in 81 patients (57 men and 24 women; age (60.5 ± 11.2) years) with standard CRT indication but no history of AF. A significant improvement of PWD (PWD responder) was defined as a relative decrease ≥ 20% from baseline PWD. The primary endpoints were new-onset AF detected by electrocardiogram (ECG) or CRT.
  
  
  RESULTS
  After (30.6 ± 7.5) months of follow-up, PWD responders (n = 43) had a significantly lower incidence of AF than did PWD nonresponders, 12% vs. 29% (P < 0.001). In Cox proportional hazard analysis, PWD responders was the only predictor of lower risk of new-onset AF (HR 0.33, 95% confidence interval 0.12 - 0.96, P = 0.033).
  
  
  CONCLUSIONS
  Improvement of P-wave dispersion after CRT was associated with a lower incidence of AF, which may be related to the significant improvement in left ventricular systolic function and the reverse modeling of the left atrium.
authors.affiliation: Center of Arrhythmia Diagnosis and Treatment, Fuwai Hospital and Cardiovascular Institute, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100037, China.
authors.forename: Li-gang
authors.initials: LG
authors.lastname: Ding
authors.forename: Wei
authors.initials: W
authors.lastname: Hua
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Chu
authors.forename: Qing
authors.initials: Q
authors.lastname: Qiao
authors.forename: Ke-ping
authors.initials: KP
authors.lastname: Chen
authors.forename: Fang-zheng
authors.initials: FZ
authors.lastname: Wang
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000517:prevention & control*; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged