目的：应用血流向量成像技术（VFM）评价梗阻性肥厚型心肌病（HOCM）患者行改良Morrow术后左心室能量损耗（EL）变化，从血流动力学角度评估由于血液黏滞度造成的能量耗散率的改变，并探讨其在评估手术疗效方面的应用价值。方法：2015年3—12月来我院行改良Morrow术的HOCM患者4例。分别于术前及术后1周进行常规超声心动图参数测量，并在VFM模式下采集标准心尖三腔动态彩色多普勒图像，应用DSA-RS1工作站进行脱机分析，逐帧计算左室内EL。计算等容收缩期、射血期、等容舒张期、充盈期4个时相的EL均值变化，结果取3个心动周期的平均，比较术前术后差异。结果：4例患者术后与术前相比，左室流出道内径、左室收缩末容积均增大，左室流出道压差、室间隔厚度、二尖瓣收缩期向前运动（SAM征）现象比例均降低，差异具有统计学意义（P<0.05）。与手术前相比，在等容收缩期和充盈期，病例1和病例2的平均EL明显增加，病例4明显减低，病例3略微增加；在等容舒张期和射血期，病例1和病例2的平均EL明显增加，病例3和病例4则明显减低。从整体变化趋势来看，病例1、病例2术后的EL较术前明显增加，而病例3、病例4则明显降低。结论：HOCM患者经改良Morrow术后，即使在患者一般情况及超声心动图检测指标都明显改善的情况下，也有患者出现EL增加的现象，EL可能成为一种精确定量评估心脏手术后不同病理生理条件下心腔内血流动力学的新指标。

Objective: To evaluate the changes of left ventricle(LV) energy loss(EL) in patients with obstructive hypertrophic cardiomyopathy(HOCM) after modified morrow procedure by vector flow mapping(VFM), and to analyze the rate of energy dissipation due to blood viscosity from a hemodynamic perspective, and to explore its clinical value in evaluating the operation effect. Methods: The data of four patients with HOCM treated by modified morrow procedure from March 2015 to December 2015 were retrospectively analyzed. Routine echocardiographic parameters were measured before and after surgery, respectively. The standard apical three-chamber dynamic color Doppler images were collected under the VFM mode, and the DSA-RS1 workstation was used for offline analysis, and the EL of LV was calculated frame by frame. The EL mean values of isovolumetric contraction phase, ejection phase, isovolumetric relaxation phase and filling phase were calculated, and the results were the mean values of three cardiac cycles, and the differences were compared before and after the operation. Results: Compared with preoperative condition, echocardiographic parameters: the left ventricular outflow tract(LVOT) diameter and left ventricular end-systolic volume were obviously increased, the LVOT gradient and the thickness of ventricular septum and the proportion of SAM were significantly decreased, the differences were obviously significant(P<0.05). EL value changes: During isovolumetric contraction phase and filling phase, EL mean values were markedly increased in patient 1 and patient 2, markedly decreased in patient 4, and slightly increased in patient 3. During isovolumetric relaxation phase and ejection phase, EL mean values were markedly increased in patient 1 and patient 2 and markedly decreased in patient 3 and patient 4. As a whole the variation trend was that the EL values in patient 1 and patient 2 increased significantly, but decreased significantly in patient 3 and patient 4. Conculsions: After modified morrow procedure, even the normal conditions and echocardiographic parameters were significantly improved in HOCM patients, an increased EL may lead to worse outcomes, EL might be an new index for precise and quantitative assessment of intracardiac blood flow dynamics under different pathophysiology conditions.