血流向量成像技术评价肥厚型心肌病左心室收缩期血流动力学特征

Evaluation of left ventricular systolic hemodynamics in patients with hypertrophic cardiomyopathy using vector flow mapping

目的应用超声血流向量成像（VFM）技术评价肥厚型心肌病（HCM）左室收缩期血流动力学特征及流场分布特点。方法随机选取肥厚型非梗阻性心肌病患者35例作为病例组，健康成年志愿者40例为对照组，比较两组左室收缩期峰值流速（Vs）、峰值流量（Fs）及收缩期负向总流量（SQ-），观察两组速度向量、流线和涡流分布特点。结果对照组Vs、Fs、SQ-及病例组Vs、Fs均由基底段、中间段至心尖段呈递减趋势，差异均有统计学意义（P〈0．05）；而病例组SQ-失去这种顺序递减趋势。病例组各节段Vs、Fs及中间段、心尖段SQ-均大于对照组，但基底段SQ-明显小于对照组（P〈0．01）。与对照组比较，病例组血流流场分布特点为速度方向混乱，流速快，流线不连续，涡流增多。结论VFM技术能够定量评价HCM患者左室收缩期血流动力学特征，并能清晰显示血流流场的分布情况。

Objective To investigate the left ventricular （LV） systolic hemodynamics and the distribution of blood flow in patients with hypertrophic cardiomyopathy（HCM） by vector flow mapping （VFM）. Methods Thirty-five random non-obstructive HCM patients （case group） and forty healthy volunteers （control group） were enrolled. Peak systolic velocity （Vs）, peak systolic flow （Fs） and total systolic negative flow （SQ-） of two groups were compared. Velocity vector, streamline and vortex distribution of two groups were observed. Results Vs,Fs,SQ- of the control group and Vs,Fs of the case group all showed a decreasing trend from the basal segments to the apical segment（ P 〈0.05）. SQ- of the case group lost this decreasing tendency. Vs,Fs of all segments and SQ- of the middle and apical segment of the case group were higher than those of the control group. SQ- of the basal segment of the case group were significantly lower than that of the control group（ P 〈0.01）. Distribution of blood flow： The velocity of blood flow was faster in the case group than that in the control group and the direction was disordered. The streamlines of the case group were discontinuous, and vortexes in the case group were more than that in the control group. Conclusions VFM technology could quantitatively evaluate LV systolic hemodynamics in patients with HCM,and can clearly show the distribution of blood flow.