title: Measurement of left ventricular dyssynchrony in patients with ischaemic cardiomyopathy: a comparison of real-time three-dimensional and tissue Doppler echocardiography.
abstract: BACKGROUND
  Real-time three-dimensional echocardiography (RT3DE) is an alternative modality to tissue Doppler imaging (TDI) for assessment of intraventricular dyssynchrony but its role is yet to be defined.
  
  
  OBJECTIVE
  To (1) compare RT3DE and TDI for assessment of intraventricular dyssynchrony; (2) determine whether the two techniques agreed regarding the magnitude of dyssynchrony and identification of the site of maximal mechanical delay; and (3) investigate the reason for disagreement.
  
  
  METHODS
  100 patients with ischaemic cardiomyopathy.
  
  
  METHODS
  Tertiary referral cardiac unit.
  
  
  METHODS
  Dispersion in time interval from QRS onset to peak sustained systolic tissue velocity by TDI (SD-T(TV)) and to minimal systolic volume by RT3DE (SD-T(3D)) between 12 ventricular segments.
  
  
  RESULTS
  RT3DE image quality was adequate for measurement of SD-T3D in 77 (77%) patients. In the whole population, SD-T(TV) was 40 (20) ms and SD-T3D was 8.3% (3.4%). RT3DE identified a smaller proportion of patients as having significant dyssynchrony than TDI (49 (64%) patients vs 32 (42%) patients; p<0.01). The correlation between SD-T(TV) and SD-T3D was poor (r = 0.11, p = NS). There was concordance between TDI and RT3DE in identifying the site of maximal mechanical delay in 12 (16%) patients. Validating the two techniques with anatomical M-mode (AMM) as a parameter of radial timing revealed better agreement with RT3DE than with TDI (chi2 = 11.8, p = 0.001).
  
  
  CONCLUSIONS
  In patients with ischaemic cardiomyopathy, TDI and RT3DE show poor agreement for evaluating the magnitude of intraventricular dyssynchrony and the site of maximal mechanical delay. This may partly relate to their respective assessment of longitudinal versus radial timing.
authors.affiliation: University of Queensland, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors.forename: Malcolm I
authors.initials: MI
authors.lastname: Burgess
authors.forename: Carly
authors.initials: C
authors.lastname: Jenkins
authors.forename: Jonathan
authors.initials: J
authors.lastname: Chan
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D018618:Echocardiography, Doppler, Color / Q000379:methods; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*