title: Reduction in mitral regurgitation in patients undergoing cardiac resynchronization treatment: assessment of predictors by two-dimensional radial strain echocardiography.
abstract: BACKGROUND
  We utilized the novel approach of 2D radial strain (2-DRS) to evaluate whether left ventricular (LV) mechanical dyssynchrony in mid-LV segments corresponding to papillary muscles insertion sites can predict early mitral regurgitation (MR) reduction post-cardiac resynchronization therapy (CRT).
  
  
  METHODS
  We evaluated 32 patients undergoing CRT (mean age 64 +/- 17 years, 54% males) with MR grade > or =3 determined by the MR jet area/left atrial area ratio (JA/LAA).
  
  
  RESULTS
  Fifteen (47%) patients responded to CRT (JA/LAA) < 25%). Sixty-seven percent of responders had mild or no residual MR and 33% had mild-to-moderate MR, while 70% of nonresponders had grade 3 or 4 MR (P = 0.0001) post CRT. The percent reduction in LV end-systolic volume was significantly higher in responders (P = 0.03), as was improvement in LVEF (P = 0.007). Significant delay of time-to-peak 2-DRS in the midposterior and inferior segments prior to CRT was found in responders compared with nonresponders (580 +/- 58 vs. 486 +/- 94, P = 0.002 and 596 +/- 79 vs. 478 +/- 127 ms, P = 0.005, respectively). Responders also had higher peak positive systolic 2-DRS in the posterior and inferior segments compared to nonresponders (22 +/- 13 vs. 12 +/- 7%, P = 0.01 and 17 +/- 9 vs. 9 +/- 7%, P = 0.02, respectively). Logistic regression analysis showed that the differences in pre-CRT inferoanterior time-to-peak 2-DRS of >110 ms and MRJA/LAA <40% as well as 2-DRS >18% in the posterior wall were significant predictors of post-CRT improvement in MR.
  
  
  CONCLUSIONS
  The presence of a significant time-to-peak delay on 2-DRS between inferior and anterior LV segments, preserved strain of posterior wall, and MRJA/LAA <40% were found to be associated with significant MR reduction in patients post-CRT.
authors.affiliation: Cardiac Non Invasive Laboratory, Division of Cardiology, Cedars Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA USA.
authors.forename: Sorel
authors.initials: S
authors.lastname: Goland
authors.forename: Asim M
authors.initials: AM
authors.lastname: Rafique
authors.forename: James
authors.initials: J
authors.lastname: Mirocha
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Siegel
authors.forename: Tasneem Z
authors.initials: TZ
authors.lastname: Naqvi
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000517:prevention & control*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome