超声血流向量成像评价继发孔型房间隔缺损右室流场及能量损耗的研究

Evaluation of right ventricular flow field and energy loss in secundum atrial septal defect by ultrasonic vector flow mapping

目的应用超声血流向量成像(VFM)技术评估继发孔型房间隔缺损(ASD)患者右室流场和能量损耗的变化规律,为定量评估ASD右室结构和功能提供参考依据。方法选取继发孔型ASD患者97例,根据所测肺动脉收缩压分为无肺动脉高压(PAH)组30例(肺动脉收缩压≤30 mm Hg)、轻度PAH组25例(30 mm Hg<肺动脉收缩压≤50 mm Hg)、中度PAH组22例(50 mm Hg<肺动脉收缩压≤70 mm Hg)和重度PAH组20例(肺动脉收缩压>70 mm Hg);另选健康志愿者29例为正常对照组。应用VFM技术测量并比较各组右室涡流参数和能量损耗大小,分析右室整体能量损耗与右心功能参数的相关性。结果对照组、无PAH组、轻度PAH组均显示在舒张早期的快速充盈期(P1)、舒张中期(P2)三尖瓣口存在较多涡流。正常对照组与无PAH组各时相的涡旋面积、循环强度、涡旋数量、能量损耗值比较差异均无统计学意义;轻度PAH组、中度PAH组、重度PAH组上述各参数随着肺动脉压的升高逐渐增大;能量损耗峰值均出现在P1期(均P<0.05)。相关性分析结果显示:P1期能量损耗值分别与Tei指数、三尖瓣E峰流速(E)及其与三尖瓣环速度(e)比值均呈正相关(r=0.768、0.941、0.937,均P<0.05),与三尖瓣环收缩期位移、右室面积变化率、e均呈负相关(r=-0.864、-0.734、-0.817,均P<0.05)。结论VFM技术可以评价ASD患者右室内流场运动和能量损耗的变化规律,为定量评估继发孔型ASD右室流体力学变化、肺动脉压大小及右室能量损耗的应用分析提供有力的依据。

Objective To evaluate the changes of right ventricular flow field and energy loss(EL)in secundum atrial septal defect(ASD)by vector flow mapping(VFM),and to provide a reference for quantitative assessment of right ventricular structure and function in ASD.Methods A total of 97 patients with ASD were divided into non PAH group(30 patients,pulmonary artery systolic pressure≤30 mm Hg,1 mm Hg=0.133 kPa),mild PAH group(25 patients,30 mm Hg<pulmonary artery systolic pressure≤50 mm Hg),moderate PAH group(22 patients,50 mm Hg<pulmonary artery systolic pressure≤70 mm Hg)and severe PAH group(20 patients,pulmonary artery systolic pressure>70 mm Hg).29 healthy volunteers were enrolled as control group.Right ventricular vortex parameters and EL were measured by VFM,and the correlation between right ventricular global EL and right ventricular parameters were analyzed.Results There were more vortices near the tricuspid valve orifice during P1 and P2 among control group,non PAH group and mild PAH group.Between moderate PAH group and severe PAH group,there were different sizes,directions and numbers of vortices in right ventricle at different time phases of cardiac cycle.There were no significant differences in vortex area,circulation,vortex quantity and EL between control group and non PAH group at each phase,despite which increased with the increases of PAH pressures among mild group,moderate group and severe PAH group(P<0.05),and EL peak appeared during P1.EL was positively correlated with Tei index,E and E/e,respectively(r=0.768,0.941,0.937,all P<0.05)and negatively correlated with TAPSE,RVFAC and e,respectively(r=-0.864,-0.734,-0.817,all P<0.05).Conclusion VFM imaging technology can evaluate the characteristics of flow field and EL of right ventricular blood flow in ASD,which can provide a reference for quantitative assessment of right ventricular hemodynamics and PAH pressure,and application analysis of right ventricular EL in ASD.