Abstract 14713: Longitudinal Strain of Mitral Papillary Muscles: Correlation with Mitral Regurgitation
Purpose: New imaging modalities have been employed for the accurate anatomical mapping of the mitral apparatus. The aim of the study was to associate global strain of mitral apparatus (papillary muscles and chordae) measured with a computational speckle tracking model and to associate global strain with the degree of mitral regurgitation.
Methods: 120 patients with mitral regurgitation (40 mild, 40 moderate and 40 severe as calculated with current guidelines) were studied with 3D echocardiography and speckle tracking. The left ventricular ejection fraction (LVEF), mitral regurgitant volume (Mvol), radius of PISA (PISAr), the longitudinal strain of the anterolateral papillary muscle (AL), posteromedial papillary muscle (PM) and their chordae (CAL, CPM) were calculated. Speckle tracking was performed from apical 2 chamber view and on the same timepoint of the cardiac cycle for all measurements. The groups were compared and the strain on papillary muscles was associated with the degree of mitral regurgitation. The global strain of mitral apparatus (Σstrain) was calculated as: Σstrain= (AL + CAL) - (PM + CPM).
Results: PISAr and Mvol had significant correlation with global longitudinal strain (mild: r=0.92, P<0.001, moderate: r=0.8, p<0.001, severe: r=0.86, p<0.001) and actually the greater the global longitudinal strain was, the more severe was the mitral regurgitation.From the group with severe mitral regurgitation, 21 had prolapse of posterior mitral leaflet and it was demonstrated that PM had significantly higher strain when compared to AL (PM: (-14.4) ± (-3.16)% compared to AL: (-6.2) ± (-1.3) %, p<0.01).
Conclusions: Global longitudinal strain of mitral valve apparatus by utilising speckle tracking can be a useful tool to associate with mitral regurgitation and may be useful in mitral valve surgery. It seems that a global strain of papillary muscles and chordate (Σstrain) almost equal to zero is associated with trivial regurgitation.
- © 2011 by American Heart Association, Inc.