title: The relationship of QRS morphology with cardiac structure and function in patients with heart failure.
abstract: BACKGROUND
  The relationship of QRS morphology with cardiac structure and function in patients with heart failure is uncertain.
  
  
  METHODS
  Patients with a clinical diagnosis of heart failure and objective evidence of cardiac dysfunction [either a left ventricular ejection fraction (LVEF) <50 % or an amino-terminal pro-brain natriuretic peptide (NT-proBNP) ≥400 pg/ml] who had been investigated by cardiac magnetic resonance imaging (CMRI) were identified. QRS duration ≥120 ms was grouped morphologically as left (LBBB), right bundle branch block (RBBB) or indeterminate.
  
  
  RESULTS
  Of 877 patients, 320 (36 %) had QRS ≥ 120 ms. Compared to patients with LBBB, those with RBBB had a lower median [inter-quartile range (IQR)] right ventricular (RV) ejection fraction [RBBB: 46 (37-57); LBBB: 52 (42-61) %; p = 0.014], greater median (IQR) RV mass [RBBB: 53 (42-73); LBBB: 45 (36-56) g; p < 0.001], higher median (IQR) plasma NT-proBNP [RBBB: 2013 (659-3573); LBBB: 1159 (589-2207) pg/ml, p = 0.026], more signs of peripheral congestion and higher prevalence of atrial fibrillation but had similar LVEF. During a median follow-up of 1302 days (IQR: 742-2237), 311 patients died. Compared with patients who had QRS < 120 ms, those with RBBB [HR 1.98, 95 % CI (1.37-2.86); p < 0.001] had a higher mortality. Age and NT-proBNP were the strongest independent predictors of mortality; neither QRS nor CMRI variables improved prediction.
  
  
  CONCLUSIONS
  In patients with heart failure and QRS ≥ 120 ms, RBBB is associated with more severe RV dysfunction and congestion and a worse prognosis. However, neither QRS morphology nor CMRI data provide independent prognostic information in a multivariable analysis including NT-proBNP.
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK. p.pel@libero.it.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Pellicori
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Anil C
authors.initials: AC
authors.lastname: Joseph
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Jufen
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Lukaschuk
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Nasser
authors.initials: N
authors.lastname: Sherwi
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Christos V
authors.initials: CV
authors.lastname: Bourantas
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Huan
authors.initials: H
authors.lastname: Loh
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Clark
authors.affiliation: Department of Cardiology, Hull York Medical School, Hull and East Yorkshire Medical Research and Teaching Centre, Castle Hill Hospital, University of Hull, Cottingham, Kingston upon Hull, HU16 5JQ, UK.
authors.forename: John Gf
authors.initials: JG
authors.lastname: Cleland
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology / Q000503:physiopathology; D015984:Causality; D015897:Comorbidity; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000473:pathology* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship; D015996:Survival Rate; D006113:United Kingdom / Q000453:epidemiology; D018497:Ventricular Dysfunction, Right / Q000401:mortality* / Q000473:pathology* / Q000503:physiopathology
keywords: Magnetic resonance imaging; Prognosis; QRS morphology; Right ventricular function