Daniel Bruce Ennis1, Tom C. Nguyen2, Gabriel R. Barnard1, Aki Itoh2, Stefan Skare3, Wolfgang Bothe2, Neil B. Ingels2, D C. Miller2
1Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; 2Department of Cardiothoracic Surgery, Stanford University, Palo Alto, CA, USA; 3Department of Radiology, Stanford University, Palo Alto, CA, USA
Left ventricular (LV) dysfunction in chronic mitral regurgitation (MR) may result, in part, from changes in LV microstructure and diffusion tensor magnetic resonance imaging (DTMRI) is well suited for the evaluation of microstructural organization. The <B>objective</B> of this study was to determine whether twelve-weeks of chronic MR alters the LV myocardial microstructure as measured with DTMRI. Comparisons between LV microstructural measures in normal sheep and chronic MR sheep demonstrate a significant (P<0.000001) increase in the rate of water diffusion (trace) and a decrease in fractional anisotropy (FA). These changes may have a direct impact on ventricular systolic and diastolic function.