A method for non-invasive estimation of mitral valve annular regional strains

INTRODUCTION: In this study, a method to assess local deformations along the mitral annulus curve is proposed. METHODS: It employs the known global geometry (from echocardiography) of the annulus during the cardiac cycle which is approximated with a closed cubic spline to generate a smooth mathematical representation of the annulus at each available time point. A point-wise mapping of the annular geometries between two consecutive times is established by minimizing the global displacements of the annulus. Hence, the displacements of the mitral annulus are determined and used to calculate the regional strains along the annulus line. RESULTS: Data obtained from sonomicrometric markers are used to test the method detailed herein. The results show that our method can predict annular displacements throughout the cardiac cycle. Strain values computed with this approach are in line with previously experimentally measured strains reported in the literature. Finally, the method is applied and illustrated on an echocardiographic recording of a healthy individual. CONCLUSION: The numerical method provided can be used to capture the regional annular strains by echocardiography and may help to predict regional dysfunctions in the mitral annulus, providing information on the pathological mechanisms.