title: Quantification of mechanical ventricular dyssynchrony: direct comparison of velocity-encoded and cine magnetic resonance imaging.
abstract: OBJECTIVE
  The preoperative assessment of mechanical dyssynchrony can help to improve patient selection in candidates for cardiac resynchronization therapy (CRT). The present study compared the performance of velocity-encoded (VENC) MRI to cine-magnetic resonance imaging (MRI) for quantifying mechanical ventricular dyssynchrony.
  
  
  METHODS
  VENC-MRI and cine-MRI were performed in 20 patients with heart failure NYHA class III and reduced ejection fraction (median: 24 %, interquartile range: 18 - 28 %) before CRT device implantation. The interventricular mechanical delay (IVMD) was assessed by VENC-MRI as the temporal difference between the onset of aortic and pulmonary flow. Intraventricular dyssynchrony was quantified by cine-MRI, using the standard deviation of time to maximal wall thickening in sixteen left ventricular segments (SDt-16). The response to CRT was assessed in a six-month follow-up.
  
  
  RESULTS
  14 patients (70 %) clinically responded to CRT. A similar accuracy was found to predict the response to CRT by measurements of the IVMD and SDt-16 (75 vs. 70 %; p = ns). The time needed for data analysis was significantly shorter for the IVMD at 1.69 min (interquartile range: 1.66 - 1.88 min) compared to 9.63 min (interquartile range: 8.92 - 11.63 min) for the SDt-16 (p < 0.0001).
  
  
  CONCLUSIONS
  Measurements of the IVMD by VENC-MRI and the SDt-16 by cine-MRI provide a similar accuracy to identify clinical responders to CRT. However, data analysis of the IVMD is significantly less time-consuming compared to data analysis of the SDt-16.
authors.affiliation: Center for Cardiology and Cardiovascular Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany. ka.muellerleile@uke.de
authors.forename: K
authors.initials: K
authors.lastname: Muellerleile
authors.forename: L
authors.initials: L
authors.lastname: Baholli
authors.forename: M
authors.initials: M
authors.lastname: Groth
authors.forename: K
authors.initials: K
authors.lastname: Koopmann
authors.forename: A
authors.initials: A
authors.lastname: Barmeyer
authors.forename: N
authors.initials: N
authors.lastname: Gosau
authors.forename: R
authors.initials: R
authors.lastname: Ventura
authors.forename: T
authors.initials: T
authors.lastname: Rostock
authors.forename: R
authors.initials: R
authors.lastname: Koester
authors.forename: G
authors.initials: G
authors.lastname: Adam
authors.forename: S
authors.initials: S
authors.lastname: Willems
authors.forename: G
authors.initials: G
authors.lastname: Lund
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000592:standards*; D019028:Magnetic Resonance Imaging, Cine / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013223:Statistics as Topic / Q000592:standards; D013997:Time Factors; D018754:Ventricular Dysfunction / Q000175:diagnosis*