title: Electrocardiographic alterations after chronic right ventricular apical pacing in patients with sinus node dysfunction.
abstract: OBJECTIVE
  The purpose of this study is to investigate the potential to induce electrical remodeling by chronic right ventricular apical (RVA) in patients with sinus node dysfunction.
  
  
  METHODS
  Ninety-two patients with sinus node dysfunction who underwent initial pacemaker implantation were included in the study. During routine clinic visits, electrocardiograms and echocardiograms were recorded. Forty-five patients were also studied as controls.
  
  
  RESULTS
  During a mean follow-up time of 3.3 +/- 0.5 years, the intrinsic QRS duration increased from 87 +/- 9 milliseconds before device implantation to 94 +/- 10 milliseconds (P < .001). The left ventricular end-diastolic diameter increased from 46 +/- 3 to 50 +/- 4 mm (P < .001), and the left ventricular ejection fraction decreased from 63% +/- 4% to 57% +/- 5% (P < .001). Logistic regression analysis revealed that elderly age at the time of pacemaker implantation (odds ratio [OR], 3.41; 95% confidence interval [CI], 1.07-10.90; P = .04), RVA pacing (OR, 3.91; 95% CI, 1.10-13.89; P = .03), and coronary artery disease (OR, 7.33; 95% CI, 1.09-50.29; P = .04) were independent predictors of the prolongation of intrinsic QRS duration.
  
  
  CONCLUSIONS
  The present study indicated that chronic RVA pacing may lead to a prolongation of intrinsic QRS duration, which could be independently predicted by elderly age, chronic RVA pacing, and the presence of coronary artery disease.
authors.affiliation: Center of Arrhythmia Diagnosis and Treatment, Fuwai Hospital and Cardiovascular Institute, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, PR 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: Xue-Bin
authors.initials: XB
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Niu
authors.forename: Ke-Ping
authors.initials: KP
authors.lastname: Chen
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012804:Sick Sinus Syndrome / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*; D018497:Ventricular Dysfunction, Right / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*