Three dimensional shape and motion analyse of mitral annulus in children with mitral valve regurgitation

Objective To analyse 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 proceed the mitral annulus 3-DE data set. The boundary points of the mitral annulus were extracted and the mitral annulus was reconstructed. The distance among the highest to the lowest points of mitral annulus (Dh-l),the two highest points distance (Dh-h),as well as the distance between the two lowest points (Dl-l) were chosen for analysis.All parameters were standardized by the diameter of the abdominal aorta. Results Dh-l in end-systolic was larger than that in end-diastolic (P0.01),Dh-h value and Dl-l value were decreased at the end-systolic point compared with those at the end-diastolic point (P0.01). In moderate and severe MR groups,Dh-h and Dl-l at end-diastolic point were longer (P0.01) compared with those in normal group respectively,and there was no difference in Dh-l between two groups (P0.05). All of three parameters in children with mild regurgitation remained normal (P0.05). Conclusion The abnormal three-dimensional space structure of the mitral annulus could lead to MR. Dh-l,Dh-h and Dl-l as the parameters of mitral annulus structure and function measured by 3DE,could be helpful for understanding the mechanism of MR.