Objective: To analysis mitral annular shape and motion throughout the cardiac cycle by quantitative three-dimensional echocardiography(3DE), and to explore the relationship between the shape and motion of mitral annulus and the degree of mitral valve regurgitation(MR).
Methods: A new mitral valve motion analysis software (CARDIO 4D VIEW) was used to process the mitral annulus 3-DE data set. The boundary points of the mitral annulus were extracted and the mitral annulus was reconstructed. The distance between the highest to the lowest points of mitral annulus (H-L), the two highest points distance (H-H), as well as the distance between the two lowest points (L-L) were selected for analysis, all parameters were standardized by the diameter of the abdominal aorta.
Results: H-L in end-systolic was larger than that in end-diastolic (P <0.01), H-H value and L-L value were decreased at the end-systolic point compared with that at the end-diastolic point (P <0.01). In moderate and severe MR groups, H-H and L-L at end-diastolic point were longer (P<0.01) compared with that in normal group respectively, and there is no difference in H-L between two groups (P>0.05). All those three parameters in children with mild regurgitation remained normal (P> 0.05).
Conclusion: The abnormal three-dimensional space structure of the mitral annulus could cause MR. H-L, H-H and L-L as the parameters of mitral annulus structure and function measured by 3DE, could be helpful for better understanding the mechanism of MR.