title: Tissue Doppler imaging of mitral annular motion is an effective surrogate of left ventricular dyssynchrony and predicts response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  Tissue Doppler imaging of basal myocardial segments has been used to predict response to cardiac resynchronization therapy (CRT). However, in patients with poor imaging windows mechanical dyssynchrony may be difficult to assess because of poor tissue characterization. We tested the hypothesis that tissue Doppler evaluation of the mitral annulus can accurately identify the presence of left ventricular dyssynchrony and predict the response to CRT.
  
  
  METHODS
  Tissue Doppler imaging of 6 mitral annular sites and 6 basal myocardial segments was performed in 21 patients with heart failure, before and at 3 months after CRT device implantation. Time to peak systolic velocity (T(s)) was determined for each site and intraventricular dyssynchrony was defined as the maximal difference in T(s) between measurement sites.
  
  
  RESULTS
  Excellent correlation was observed between mitral annular and basal segment measurements of T(s) (r = 0.90, P < .001 at baseline and r = 0.93, P < .001 at follow-up) and maximal difference in T(s) between measurement sites (r = 0.90, P < .001 at baseline and r = 0.90, P = .003 at follow-up). Receiver operator characteristic analysis for the mitral annulus measurements demonstrated that an optimal cut-off value of T(s) = 179 milliseconds differentiated responders from nonresponders with a sensitivity of 86% and specificity of 82%; similarly, a cut-off value of maximal difference in T(s) between measurement sites = 105 milliseconds for intraventricular dyssynchrony differentiated responders from nonresponders with a sensitivity of 86% and specificity of 73%.
  
  
  CONCLUSIONS
  Tissue Doppler assessment of mitral annular motion can accurately identify left ventricular dyssynchrony and predict positive response to CRT.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
authors.forename: Xia Ping
authors.initials: XP
authors.lastname: Yuan
authors.forename: James A
authors.initials: JA
authors.lastname: White
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Maria
authors.initials: M
authors.lastname: Drangova
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009200:Myocardial Contraction / Q000502:physiology*; D011379:Prognosis; D012372:ROC Curve; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy