超声血流向量成像评价2型糖尿病患者等容收缩期左心室流场状态

Left Ventricular Flow Field Change of Isovolumetric Contraction Phase in Patients with Type 2 Diabetes Mellitus Assessed by Ultrasonic Vector Flow Mapping

目的采用超声血流向量成像(vector flow mapping,VFM)技术评价2型糖尿病(type 2 diabetes mellitus,D2M)患者等容收缩期(isovolumetric contraction phase,IVC)左心室(left ventricle,LV)血液流场状态,揭示D2M患者左心室血流动力学异常。方法 51例D2M患者为D2M观察组,42例健康成人为对照组。采集连续3个心动周期及标准心尖四腔(apical four chamber,AP4c)常规二维灰阶图像和彩色多普勒血流动态图像,在机获取左心房(left atrium,LA)和LV内径、射血分数(ejection fraction,EF)、等容收缩时间(isovolumetric contraction time,ICT)、射血前期时间(pre ejection time,PET)等参数。将AP4c彩色多普勒血流动态图导入图像后处理工作站离线分析,获取IVC左心室能量损耗(energy loss,EL)及涡旋循环强度(Circulation)、中心位置、面积(area)等参数。比较两组常规心脏解剖和功能参数、EL及涡旋参数,并将EL与涡旋参数、LV流场参数与IVC时间参数进行关联性分析。结果等容收缩期LV流场参数比较:D2M组IVC总能量损耗(EL_SUM)及平均能量损耗(EL_AVG)较正常组明显增高,差异有统计学意义(P<0.01);D2M组涡旋循环强度(Circulation)、涡旋中心横向坐标(Vortex-X)均较正常组增高,而涡旋中心纵向坐标(Vortex-Y)较正常组降低,差异均有统计学意义(P<0.05)。EL与涡旋参数相关性分析:两组EL_SUM及EL_AVG与Circulation呈明显正相关关系(P<0.01);D2M组EL_SUM与Vortex-Y呈负相关关系(P<0.05),EL_AVG与Vortex-Y呈明显负相关关系(P<0.01)。结论 D2M患者等容收缩期左心室血液流场状态发生异常改变和能量损耗明显增加,有可能导致左心室射血功能异常。

Objective To evaluate the state of left ventricular flow field in patients with type 2 diabetes mellitus during isovolumetric contraction period using ultrasonic vector mapping,and demonsrate the potential abnormal change of intraventricular fluid dynamics. Methods Fifty patients with type 2 diabetes mellitus as case group and 42 healthy adults as control group were employed randomly. The standard dynamic apical four chambers （AP4c） two- dimensional gray -scale echocardiographic images and color Doppler flow images for 3 completed cardiac cycles were acquired for the measurement of general anatomical and func- tional parameters of LA and LV, and EF, ICT and PET of LV. The AP4c color Doppler flow dynamic images were analyzed using off - line workstation for derivation of EL, vortex circulation, the position of vortex center and vortex area of LV during IVC. The differ- ence of general cardiac anatomical and functional parameters and EL and vortex parameters between 2 groups were compared and the correlation between EL parameters and vortex parameters, and the correlation between LV flow field parameters and time param- eters during IVC between the groups were analyzed. Results 1. Difference of flow field parameters of LV during 1VC：Compared between D2M group and control group, both the ELSUM and EL AVG were higher with statistically significant differences （P 〈 0. 01 ）, the vortex circulation and the X axis of vortex center （Vortex - X） were higher, but the Y axis of vortex center （Vortex - Y）was lower with statistical differences （ P 〈 0.05 ）. 2. Correlation between EL and vortex parameters ：There was a significant positive correlation between EL_SUM, as well as EL AVG with vortex circulation in these two groups （P 〈 0.01 ）. A negative correlation was discovered between EL_SUM and Vortex-Y（P 〈 0.05）, and also a significant negative correlation between EL_AVG and Vor- tex - Y （P 〈 0.01 ） in D2M group. Conclusion The abnormal changes of left intraventricular flow field in patients with type 2 diabetes mellitus were performed during isovolumetric contraction period. The change of vortex motion model could induce a higher energy loss, and might eventually lead to the abnormal ejection function of left ventricle in D2M patients.