Abstract 9708: Strain Rate of Mitral Papillary Muscles: a New Imaging Prognostic Tool for Mitral Valve Repair
Purpose: New imaging modalities have been employed for the accurate anatomical mapping of the mitral apparatus. The aim of the study was to assess strain of mitral apparatus (papillary muscles and chordae) with a computational speckle tracking model and to associate strain with residual regurgitation post mitral valve surgical repair.
Methods: 50 patients with posterior mitral leaflet prolapse underwent mitral valve repair. The left ventricular ejection fraction (LVEF), mitral regurgitant volume (Mvol), the longitudinal strain of the anterolateral papillary muscle (AL), posteromedial papillary muscle (PM) and their chordae (CAL, CPM) were calculated before and 6 months after the repair.Speckle tracking was performed with Toshiba Artida, from apical 2 chamber view and on the same timepoint of the cardiac cycle for all measurements. The groups (pre and post surgical repair) were compared and the strain on papillary muscles was associated with the recurrence of mitral regurgitation post-repair.The global strain of mitral apparatus (Σstrain ) was calculated as: Σstrain= (AL + CAL) - (PM + CPM).
Results: Six patients (15%) had residual mitral regurgitation of grade II and III. LVEF before and after the operation did not differ (pre: 69 ± 5%, post: 68.2 ± 3%, p<0.01). PM had significantly higher strain when compared to AL (PM pre: (-18.9) ± (-3)% compared to AL pre: (-4) ± (-1.1) %, p<0.01), while post repair the strain between PM and AL was similar. Patients with residual mitral regurgitation had residual high PM longitudinal strain ((-15.3) ± (-1.4) %). Σstrain overall was significantly reduced post repair (Σstrain pre : (-19.2) ± (-3) % , Σstrain post: (-2.2) ± (-0.6) %, p<0.01).
Conclusions: Longitudinal strain of mitral valve apparatus by utilising speckle tracking can be a useful prognostic tool for post repair mitral regurgitation. 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.