超声血流向量成像技术评价扩张型心肌病左心室血流状态的变化

目的 应用超声血流向量成像(VFM)技术探讨心腔内血流的结构变化及其与左室功能之间的关系.方法 选取扩张型心肌病患者26例、正常对照44例为观察对象,利用VFM软件采集左室内血流向量图像,应用VFM分析软件DSA-RS1测量收缩期心尖部-主动脉瓣口速度阶差(△Vs)、心尖部-主动脉瓣口距离(Ds)、半距对应速度(Vs1/2);舒张期二尖瓣口-心尖部速度阶差(△Vd)、二尖瓣口-心尖部距离(Dd)、半距对应速度(Vd1/2).结果 与对照组相比,DCM组收缩期△Vs、Vs1/2与舒张期△Vd、Vd1/2明显降低,收缩期Ds与舒张期Dd明显延长,差异均具有统计学意义(P＜0.05).Ds、Dd与舒张末期容积、收缩末期容积、左室内径呈正相关(r＞0.4,P＜0.01),与收缩功能呈负相关(r＞0.3,P＜0.01);Vs1/2、Vd1/2与舒张末期容积、收缩末期容积、左室内径呈负相关(r＞0.3,P＜0.01),与收缩功能呈正相关(r＞0.3,P＜0.01).结论 扩张型心肌病患者心腔内血流速度明显低于正常人,VFM是一种无创评价扩张型心肌病左室内血流动力学变化的新方法.

Evaluation of flow structure within left ventricle in patients with dilated cardiomyopathy by vector flow mapping

Objective To evaluate left ventricular function in the way of intracavitary flow dynamics by vector flow mapping (VFM) with echocardiography, and to discuss its clinical usefulness. Methods Twenty-six patients with dilated cardiomyopathy(DCM) and 44 healthy controls were involved. The velocity distribution imagings on the section plane of the flow in the left ventricle were obtained by VFM,and series parameters of velocity and distance were measured with DSA-RS1 software,including systolic parameters,such as velocity gradient from cardiac apex to the aortic valve(△Vs) ,distance from cardiac apex to the aortic valve(Ds), velocity according to half distance (Vs1/2), and diastolic parameters, such as velocity gradient from the mitral orifice to the apex(△Vd), distance from mitral orifice to cardiac apex(Dd),velocity according to half distance(Vd1/2). Results Compared with the values in the control group, parameters of systolic velocity(△Vs, Vs1/2 ) and parameters of diastolic velocity ( △Vd, Vd1/2 ) were significantly lower, parameter of systolic distance (Ds) and parameter of diastolic distance (Dd) were significantly longer( P ＜0.05). Ds,Dd were positive correlated with left ventricular(LV) end-diastolic volume(EDV), end-systolic volume (ESV) ,LV diameter ( r ＞0.4, P ＜0.01 ), and negtively correlated with LV ejection fraction(EF) ( r ＞0.3, P ＜0.01 ). Vs1/2, Vd1/2 were negtively correlated with EDV, ESV, LV diameter ( r ＞0.3, P ＜0.01 ),and positive correlated with EF( r ＞0.3, P ＜0.01 ). Conclusions The velocity of DCM group was lower than that of control group, VFM is a new noninvasive and clinically useful parameter for the evaluation of intracavitary flow dynamics.