title: Interventricular mechanical dyssynchrony: quantification with velocity-encoded MR imaging.
abstract: OBJECTIVE
  To evaluate the performance of velocity-encoded (VENC) magnetic resonance (MR) imaging, as compared with pulsed-wave echocardiography (PW-ECHO), in the quantification of interventricular mechanical dyssynchrony (IVMD) as a predictor of response to cardiac resynchronization therapy (CRT).
  
  
  METHODS
  The study was approved by the local ethics committee, and all patients provided written informed consent. The study involved the examination of 45 patients (nine women, 36 men; median age, 60 years; interquartile age range, 47-69 years) with New York Heart Association class 2.0-3.0 heart failure and a reduced left ventricular ejection fraction (median, 25%; interquartile range, 21%-32%), with (n = 25) or without (n = 20) left bundle branch block. Aortic and pulmonary flow curves were constructed by using VENC MR imaging and PW-ECHO. IVMD was defined as the difference between the onset of aortic flow and the onset of pulmonary flow. Intraclass correlation coefficient, Spearman correlation coefficient, Bland-Altman, and Cohen kappa analyses were used to assess agreement between observers and methods.
  
  
  RESULTS
  Inter- and intraobserver agreement regarding VENC MR imaging IVMD measurements was very good (intraclass r = 0.96, P < .001; mean bias, -3 msec +/- 11 [standard deviation] and 0 msec +/- 10, respectively). A strong correlation (Spearman r = 0.92, P < .001) and strong agreement (mean difference, -6 msec +/- 16) were found between VENC MR imaging and PW-ECHO in the quantification of IVMD. Agreement between VENC MR imaging and PW-ECHO in the identification of potential responders to CRT was excellent (Cohen kappa = 0.94).
  
  
  CONCLUSIONS
  VENC MR measurements of IVMD are equivalent to PW-ECHO measurements and can be used to identify potential responders to CRT.
authors.affiliation: Center for Cardiology and Cardiovascular Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. ka.muellerleile@uke.de
authors.forename: Kai
authors.initials: K
authors.lastname: Muellerleile
authors.forename: Loant
authors.initials: L
authors.lastname: Baholli
authors.forename: Michael
authors.initials: M
authors.lastname: Groth
authors.forename: Achim A
authors.initials: AA
authors.lastname: Barmeyer
authors.forename: Katharina
authors.initials: K
authors.lastname: Koopmann
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ventura
authors.forename: Ralf
authors.initials: R
authors.lastname: Koester
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Stephan
authors.initials: S
authors.lastname: Willems
authors.forename: Gunnar K
authors.initials: GK
authors.lastname: Lund
mesh_terms: D000368:Aged; D001021:Aortic Valve; D001783:Blood Flow Velocity; D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011664:Pulmonary Valve; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy