血流向量成像评价室壁瘤患者左心室收缩期血流动力学特点

目的 探讨血流向量成像(vector flow mapping,VFM)技术检测心肌梗死并发室壁瘤患者室壁节段性运动异常的心腔内血流流场的变化规律。方法 心肌梗死并发室壁瘤患者31例和健康志愿者35例，应用VFM技术分析其等容收缩期、快速射血期及缓慢射血期的涡流及流线特征、收缩早期左室流出道速度阶差(△V)和室壁瘤瘤颈部平均血流量的变化。结果 室壁瘤组与对照组的不同主要体现在室壁瘤体内收缩期持续存在涡流;室壁瘤组瘤体内涡流横径与纵径乘积与二维超声测量室壁瘤横径与纵径乘积显著相关(P＜0.01);室壁瘤组收缩期涡流持续时间占整个收缩期百分比（并用心率标化）显著高于对照组(P＜0.01);室壁瘤患者收缩早期左室流出道速度阶差(△V)明显降低(P＜0.05);经过室壁瘤瘤颈的平均血流量明显减少(P＜0.01)。结论VFM技术能够直观显示室壁瘤患者左室心腔内血流动力学变化，定量测量局部血流速度及血流量。

Assessment of the hemodynamics of left ventricle in ventricular aneurysm during the contraction phase by vector flow mapping

Objective To evaluate the systolic function of left ventricle in myocardial infarction(MI)patients with ventricular aneurysm and the changing law of blood flow in ventricle with regional abnormality of wall movement by vector flow mapping (VFM).Methods Tirty-one MI patients with ventricular aneurysm and 35 healthy participants were enrolled in this study.The characteristic of vector and streamline,and the changing of the velocity gradient in left ventricular outflow tract (LVOT), and the average flow quantity through aneurysm neck were detected in the isovolumic contraction period, the rapid ejection period and the slow ejection period by VFM.Results The distinction between aneurysm and control group was mainly the persistance of vortex in aneurysm.The size of vortex in aneurysm was highly correlated with that measured by 2-D ultrasound(P ＜0.01).The percentage of vortex duration to cardiac cycle in patients group was significantly greater than that in control group(P ＜0.01).In the early systolic contraction the velocity gradient in LVOT in patients with ventricular aneurysm was smaller than that of control group(P ＜0.05).The average flow through aneurysm neck was notablely decreased compared with control group(P ＜0.01).Conclusions VFM can reveal the hemodynamics of left ventricle with aneurysm directly as well as quantitively measure the regional velocity and flow quantity.VFM can evaluate the systolic function of left ventricle exactly.