title: Reliability of echocardiographic indices of dyssynchrony.
abstract: BACKGROUND
  Echocardiographic indices of dyssynchrony are increasingly used to select candidates for cardiac resynchronization therapy. For widespread screening of heart failure patients, such variables need to be comparable when evaluated by different operators using different equipment.
  
  
  OBJECTIVE
  To evaluate the reproducibility and obtainability of echocardiographic indices of mechanical dyssynchrony, we studied 40 subjects stratified according to QRS morphology and systolic function. Two echocardiograms were performed on each patient by different sonographers on different machines and each study was analyzed by two observers.
  
  
  RESULTS
  All blood-pool and tissue Doppler indices of dyssynchrony were obtainable in over 97% of cases. Blood-pool Doppler measures were the most reproducible indices of intraventricular dyssynchrony (aortic ejection delay) and interventricular dyssynchrony (aortopulmonary difference in ejection delay). For annular tissue Doppler delays, the time to peak velocity was consistently more reproducible than the time to velocity onset.
  
  
  CONCLUSIONS
  Differences in the reliability of echocardiographic indices may affect their suitability as screening tests for dyssynchrony.
authors.affiliation: North Shore and Middlemore Hospitals, Auckland, New Zealand.
authors.forename: Ruvin S
authors.initials: RS
authors.lastname: Gabriel
authors.forename: Tapash K
authors.initials: TK
authors.lastname: Bakshi
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Scott
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Christiansen
authors.forename: Hitesh
authors.initials: H
authors.lastname: Patel
authors.forename: Selwyn P
authors.initials: SP
authors.lastname: Wong
authors.forename: Guy P
authors.initials: GP
authors.lastname: Armstrong
mesh_terms: D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004452:Echocardiography / Q000592:standards; D018619:Echocardiography, Doppler, Pulsed; D006801:Humans; D015203:Reproducibility of Results; D012720:Severity of Illness Index