title: Native and paced QRS duration in right ventricular apex paced patients.
abstract: BACKGROUND
  The value between paced QRS duration (pQRSd) and native QRS duration (nQRSd) in paced population has not been compared. The relation between nQRSd and pQRSd remains undefined now.
  
  
  RESULTS
  A total of 310 right ventricular apex (RVA) paced patients were enrolled. The correlation coefficients between nQRSd and pQRSd to left ventricular (LV) dimensions and ejection fraction (LVEF) were calculated and then compared. The association between pQRSd and nQRSd was examined. pQRSd was better correlated with LVDD, LVDS, and LVEF than nQRSd in all patients or patients with no intraventricular conduction block (NIVCB, n = 136) or complete right bundle-branch block (CRBB, n = 86) (all P < .01). pQRSd was positively correlated with nQRSd in NIVCB, CRBB, and complete left bundle-branch block (CLBB, n = 45) patients (r = 0.408, 0.465, and 0.766, respectively; all P < .001). However, pQRSd was not different between NIVCB, CRBB, and CLBB patients (P > .05) after adjusting for LVEF and LV dimensions.
  
  
  CONCLUSIONS
  pQRSd is superior to nQRSd in terms of reflecting LV structures and function in RVA-paced patients. Bundle branch block (BBB) has no significant effect on pQRSd and thus further studies are needed to clarify whether BBB is an independent risk factor for the development of heart failure after RVA pacing.
authors.affiliation: Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, China.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Pan
authors.forename: Yangang
authors.initials: Y
authors.lastname: Su
authors.forename: Aijun
authors.initials: A
authors.lastname: Sun
authors.forename: Xue
authors.initials: X
authors.lastname: Gong
authors.forename: Junbo
authors.initials: J
authors.lastname: Ge
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D006333:Heart Failure / Q000209:etiology / Q000517:prevention & control*; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis*; D016278:Ventricular Function, Right / Q000502:physiology