三维斑点追踪成像技术评价肥厚型心肌病左心室心肌功能

Real Time Three-dimensional Speckle Tracing Imaging in Evaluating Left Ventricular Function in Patients with Hypertrophic Cardiomyopathy

目的应用三维斑点追踪成像(3D-STI)技术测量射血分数在正常范围的非梗阻性肥厚型心肌病(HCM)患者的左心室心肌功能。资料与方法选取研究组28例非梗阻性HCM患者及对照组30例健康志愿者,行常规二维超声心动图和3D-STI检查,比较两组常规超声心动图指标左心室室间隔舒张末期厚度(IVST)、左心室后壁舒张末期厚度(LVPWT)、左心室内径、左心室容积、收缩末期左心室容积、二尖瓣口舒张早期血流速度峰值(E)、二尖瓣口舒张晚期血流速度峰值(A)、主动脉瓣及左心室流出道血流频谱,描绘左心室流出道的速度频谱得出左心室流出道最大压差(LVOT-PG)、左心室流出道速度时间积分(LVOT-VTI)、组织多普勒二尖瓣环舒张早期速度峰值(Ea)、二尖瓣环舒张晚期速度峰值(Aa),计算E/A、Ea/Aa、E/Ea,并比较左心室三维射血分数、左心室球形指数、面积应变(GAS)、纵向应变(GLS)、圆周应变(GCS)、径向应变(GRS)的差异。结果与对照组比较,HCM组左心室IVST和LVPWT增加(P<0.01),Ea/Aa、E/A显著减低(P<0.01),E/Ea增高(P<0.01),LVOT-PG、LVOT-VTI明显增加(P<0.05、P<0.01);与对照组三维应变值比较,HCM组GCS、GAS、GRS、GLS明显减低(P<0.01),局部应变值显示心尖水平和乳头肌水平减低,其中室间隔、前壁、下壁等节段应变值减低更显著。结论 HCM患者存在不同程度的心肌收缩力下降,局部心肌功能下降多位于乳头肌水平和心尖水平,并且减低的节段集中在室间隔、前壁、下壁等处。3D-STI可以作为评价HCM患者左心室早期整体及局部心肌功能损害的一种新技术。

Purpose To evaluate left ventricular function in patients with non-obstructive hypertrophic cardiomyopathy（HCM） by using three-dimensional speckle tracking imaging（3D-STI）. Materials and Methods Twenty-eight patients with non-obstructive hypertrophic cardiomyopathy（HCM group） and 30 healthy volunteers（control group） underwent both conventional two-dimensional echocardiography and 3D-STI. Indexes of conventional echocardiography including interventricular septal thickness（IVST）, left ventricular posterior wall at end-diastolic thickness（LVPWT）, left ventricular diameter, left ventricular volume, end-systolic left ventricular volume, peak velocity of early diastolic mitral valve, peak diastolic of late diastolic mitral valve, outflow tract frequency spectrum of the aortic valve and left ventricular were compared between the two groups to get the pressure difference and velocity time integral of the left ventricular outflow tract. Early and late diastolic peak velocity of mitral annular were calculated and E/A, Ea/Aa, E/Ea were also obtained. 3D-STI indicators including three-dimensional left ventricular ejection fraction（3D-LVEF）, sphericity index（SPI） and global area of strain（GAS）, global longitudinal train（GLS）, global circumferential strain（GCS）, global radial strain（GRS） were also compared. Results In HCM group, IVST, LVPWT and E/Ea increased（P〈0.01）, Ea/Aa and E/A decreased significantly（P〈0.01）, LVOT-PG and LVOT-VTI increased significantly（P〈0.05 or P〈0.01）. GCS, GAS, GLS and GRS were significant lower in HCM group than those in control group（P〈0.01）. Local strain values at the level of papillary muscle and apex were decreased, which were significantly decreased at ventricular septum, anterior wall and inferior wall. Conclusion HCM patients have various degree of decreased myocardial contractility. The real time 3D-STI offers a novel way to assess the left ventricular function of patients with HCM.