Quantitative evaluation of the dynamic changes of mitral annulus in patients with degenerative mitral regurgitation by three-dimensional echocardiography / 中华超声影像学杂志

ABSTRACT

Objective:To quantitatively analyze the static geometric structure and dynamic changes of the mitral annulus(MA) in patients with degenerative mitral regurgitation (DMR) by three-dimensional transthoracic echocardiography.Methods:Thirty-five patients with DMR (both mitral valve prolapse and Barlow) were collected as DMR group in Yunnan Fuwai Cardiovascular Disease Hospital from August 2019 to March 2021, and 42 healthy volunteers were selected as control group during the same period. The mitral annulus area (MAA), mitral annulus perimeter (MAP), mitral annulus anterolateral-posteromedial diameter (DALPM), anteroposterior diameter (DAP), non-planar angle (NPA), mitral annulus height (AH), and the ratio of height to intercommissural diameter (AHCWR) were measured during the late-diastole, early-systole, mid-systole and late-systole, and the systolic change fractions of the above parameters were calculated. The differences of static structure and dynamic change of MA between the two groups were compared, and the characteristics of dynamic change of MA in the whole cardiac cycle were analyzed.Results:Static structure MAA, MAP, DAP and DALPM in DMR group were higher than those in control group during the whole cardiac cycle, and the differences were statistically significant (all P<0.05). Compared with the control group, the saddle structure in DMR group were flattened in the middle and late contraction stages (AHCWR 0.17±0.01 vs 0.21±0.01 and 0.15±0.01 vs 0.23±0.01, both P<0.05), while the saddle structure was relatively preserved in the rest of the contraction stage. Dynamic changes Presystole contraction (MAA, MAP, DAP, DALPM decreased, all P<0.05) were appeared durng the late-diastole and early-systole in the control group, and saddle shape deepened (NPA decreased, AH and AHCWR increased, all P<0.05). Compared with the control group, presystole MA contraction and saddle deepening disappeared in DMR group (there were no significant differences in all MA parameters between late-diastole and early-systole, all P>0.05). The systolic dynamic changes were weaker and impaired when compared with the control group, which showed that the systolic change scores of DALPM, NPA and AHCWR were lower than those of the control group (all P<0.05). There were no statistical differences in the 4 time phases of MA parameters except DAP (all P>0.05). Conclusions:The saddle-shape structure of MA in normal subjects is obvious, and the dynamic change of MA in the cardiac cycle is significant, with obvious contraction before contraction and saddle-shape deepening. The saddle structure of DMR patient is flattened in the middle and late systolic period, and the MA kinetic energy of DMR patient is weakened throughout the cardiac cycle, the contraction phenomenon disappeared before contraction, and the dynamic change of systolic period is impaired to varying degrees.