三维斑点追踪成像技术评价冠状动脉不同程度狭窄心肌应变

目的应用三维斑点追踪成像（3D-STI）技术评价冠状动脉左前降支（LAD）不同程度狭窄心肌各节段应变。 方法选取2013年12月至2014年5月北京军区总医院疑诊冠状动脉粥样硬化性心脏病并接受冠状动脉造影的60例患者。根据冠状动脉造影LAD狭窄程度分为：对照组18例（LAD无明确狭窄）、轻度狭窄组（狭窄率≤50%）10例、中度狭窄组（50%<狭窄率≤75%）10例、重度狭窄组（狭窄率>75%）22例。应用3D-STI技术获得LAD供血区域各节段基底部前壁（BA）、基底部近前间隔壁（BAS）、中部前壁（MA）、中部近前壁间隔壁（MAS）、心尖部前壁（AA）、心尖部间隔壁（AS）、心尖部（A）]应变参数，包括长轴应变（LS）、径向应变（RS）、圆周应变（CS）以及面积应变（AS）。采用单因素方差分析比较4组患者各节段LS、RS、CS、AS差异，进一步组间两两比较采用LSD-t检验。 结果（1）轻度狭窄组患者各节段LS与对照组患者比较差异均无统计学意义。中度狭窄组患者各节段LS均低于对照组患者，且差异均有统计学意义（t=-7.58、-4.76、-4.38、-4.64、-7.37、-5.00、-7.24，P均<0.05）。中度狭窄组患者AS的LS低于轻度狭窄组患者，且差异有统计学意义（t=-3.73，P<0.05）；其余各节段LS与轻度狭窄组患者比较差异均无统计学意义。重度狭窄组患者各节段LS均低于对照组、轻度狭窄组、中度狭窄组患者，且差异均有统计学意义（重度狭窄组与对照组比较，t=-10.80、-13.96、-13.65、-15.25、-11.11、-11.66、-10.77，P均<0.05；重度狭窄组与轻度狭窄组比较，t=-6.76、-9.96、-9.27、-10.60、-7.45、-8.59、-6.88，P均<0.05；重度狭窄组与中度狭窄组比较，t=-5.23、-8.02、-7.89、-9.01、-6.08、-6.16、-5.49，P均<0.05）。（2）轻度狭窄组患者各节段RS与对照组患者比较差异均无统计学意义。中度狭窄组患者BA的RS与对照组患者比较差异无统计学意义，其余各节段RS均低于对照组患者，且差异均有统计学意义（t=1.16、2.78、3.28、4.86、2.11、4.03，P均<0.05）。中度狭窄组患者各节段RS与轻度狭窄组患者比较差异均无统计学意义。重度狭窄组患者各节段RS均低于对照组、轻度狭窄组患者，且差异均有统计学意义（重度狭窄组与对照组比较，t=4.02、3.26、5.91、5.74、5.92、5.67、5.11，P均<0.05；重度狭窄组与轻度狭窄组比较，t=3.60、2.83、3.96、3.55、3.21、3.31、2.85，P均<0.05），但与中度狭窄组患者比较差异则均无统计学意义。（3）轻度狭窄组患者各节段CS与对照组患者比较差异均无统计学意义。中度狭窄组患者BA、MA的CS与对照组患者比较差异均无统计学意义，其余各节段CS均低于对照组患者，且差异均有统计学意义（t=-6.28、-5.56、-7.37、-4.58、-3.56，P均<0.05）。中度狭窄组患者各节段CS与轻度狭窄组患者比较差异均无统计学意义。重度狭窄组患者各节段CS均低于对照组、轻度狭窄组、中度狭窄组患者，且差异均有统计学意义（重度狭窄组与对照组比较，t=-16.54、-7.58、-12.87、-14.15、-15.93、-14.79、-13.38，P均<0.05；重度狭窄组与轻度狭窄组比较，t=-10.19、-6.28、-6.94、-8.19、-9.59、-9.30、-9.15，P均<0.05；重度狭窄组与中度狭窄组比较，t=-6.20、-3.92、-7.62、-5.21、-6.47、-7.90、-7.56，P均<0.05）。（4）轻度狭窄组患者BA的AS与对照组患者比较差异无统计学意义，其余各节段AS均低于对照组患者，且差异均有统计学意义（t=-4.97、-3.16、-3.52、-4.92、-4.55、-7.32，P均<0.05）。中度狭窄组患者各节段AS均低于对照组患者，且差异均有统计学意义（t=-4.69、-7.00、-4.47、-4.00、-6.60、-4.90、-7.78，P均<0.05）。中度狭窄组患者BA、BAS的AS均低于轻度狭窄组患者，且差异均有统计学意义（t=-1.87、-2.30，P均<0.05）；其余各节段AS与轻度狭窄组患者比较差异均无统计学意义。重度狭窄组患者各节段AS均低于对照组、轻度狭窄组、中度狭窄组患者，且差异均有统计学意义（重度狭窄组与对照组比较，t=-9.19、-14.33、-9.54、-9.41、-11.39、-10.35、-14.19，P均<0.05；重度狭窄组与轻度狭窄组比较，t=-4.51、-7.68、-4.13、-5.19、-3.55、-5.50、-3.62，P均<0.05；重度狭窄组与中度狭窄组比较，t=-2.15、-4.86、-4.55、-4.26、-3.86、-3.71、-3.39，P均<0.05）。 结论LAD不同程度狭窄心肌各节段的应变降低存在显著差异。3D-STI技术获取的应变参数可用于评价>50%的狭窄。而AS作为一项更敏感的指标，可评价冠状动脉轻度狭窄导致的心肌应变降低。

Evaluation of regional myocardial strains in patients with left anterior descending artery stenosis by three-dimensional speckle tracking imaging

ObjectiveTo determine the value of three-dimensional speckle tracking imaging (3D-STI) in diagnosis of coronary artery diseases in patients with stenosis of left anterior descending artery (LAD). MethodsSixty patients with clinical possible diagnosis of coronary heart disease (CHD) in Beijing Army General Hospital from December 2013 to May 2014 were enrolled in the study. According to the results of coronary angiography, the patients were divided into four groups: the control group with 18 cases without LAD stenosis, the mild stenosis group (luminal stenosis rate≤50%) with 10 cases, the moderate stenosis group (50%75%) with 22 cases. The echocardiographic parameter included long axis strain (LS), radial strain (RS), circumferential strain (CS) and area strain (AS) acquired by 3D-STI in 7 myocardial segments basis anterior (BA), basis anterior septal (BAS), middle anterior (MA), middle anterior septal (MAS), apex anterior (AA), apex septal (AS), apex (A)] of left ventricle supplied by LAD. The differences of these parameters between the different groups were compared. Results(1) Results of LS: the mild stenosis group had no significant difference were observed compared with the control group. LS of moderate stenosis group was significantly lower than that of control group (t=-7.58, -4.76, -4.38, -4.64, -7.37, -5.00 and -7.24, all P<0.05), and part of the segments (AS) LS was significantly lower than that of mild stenosis group (t=-3.73, P<0.05). The other segments LS of moderate stenosis group had no significant difference were observed compared with that of the mild stenosis group. Each segment LS of severe stenosis group was significantly lower than that of control group, the mild stenosis group and moderate stenosis group (severe stenosis group compared with control group, t=-10.80, -13.96, -13.65, -15.25, -11.11, -11.66 and -10.77, all P<0.05; severe stenosis group compared with mild group, t=-6.76, -9.96, -9.27, -10.60, -7.45, -8.59 and -6.88, all P<0.05; severe stenosis group compared with moderate group, t=-5.23, -8.02, -7.89, -9.01, -6.08, -6.16 and -5.49, all P<0.05). (2) Results of RS: the mild stenosis group had no significant difference were observed compared with the control group. BA segment RS of moderate stenosis group has no significant difference were observed compared with that of the control group; the other segments RS was significantly lower than that of control group (t=1.16, 2.78, 3.28, 4.86, 2.11 and 4.03, all P<0.05). RS of moderate stenosis group has no statistical significance difference compared with that of mild stenosis group. Each segment RS of severe stenosis group was significantly lower than that of control group and mild stenosis group (severe stenosis group compared with control group, t=4.02, 3.26, 5.91, 5.74, 5.92, 5.67 and 5.11, all P<0.05; severe stenosis group compared with mild group, t=3.60, 2.83, 3.96, 3.55, 3.21, 3.31 and 2.85, all P<0.05), but the difference compared with moderate stenosis group had no statistical significance. (3) Results of CS: the mild stenosis group had no significant difference were observed compared with the control group. BA and MA segments circumferential strain of moderate stenosis group had no significant difference were observed compared with those of the control group; the other segments CS was significantly lower than that of control group (t=-6.28, -5.56, -7.37, -4.58 and -3.56, all P<0.05), each segment CS in moderate stenosis group has no statistical significance difference compared with that of mild stenosis group. Each segment CS of severe stenosis group was significantly lower than that of control group, the mild stenosis group and moderate stenosis group (severe stenosis group compared with control group, t=-16.54, -7.58, -12.87, -14.15, -15.93, -14.79 and -13.38, all P<0.05; severe stenosis group compared with mild group, t=-10.19, -6.28, -6.94, -8.19, -9.59, -9.30 and -9.15, all P<0.05; severe stenosis group compared with moderate group, t=-6.20, -3.92, -7.62, -5.21, -6.47, -7.90 and -7.56, all P<0.05). (4) Results of AS: BA segment AS of mild stenosis group had no significant difference were observed compared with that of the control group; the other segments AS was significantly lower than that of control group (t=-4.97, -3.16, -3.52, -4.92, -4.55 and -7.32, all P<0.05). Each segmental AS of moderate stenosis group was significantly lower than that of control group (t=-4.69, -7.00, -4.47, -4.00, -6.60, -4.90 and -7.78, all P<0.05), and part of the segments (BA and BAS) was significantly lower than that of mild stenosis group (t=-1.87 and -2.30, both P<0.05), the other segments AS had no significant difference were observed compared with that of the mild stenosis group. The strain of severe stenosis group was significantly lower than that of control group, mild stenosis, and moderate stenosis group (severe stenosis group compared with control group, t=-9.19, -14.33, -9.54, -9.41, -11.39, -10.35 and -14.19, all P<0.05; severe stenosis group compared with mild group, t=-4.51, -7.68, -4.13, -5.19, -3.55, -5.50 and -3.62, all P<0.05; severe stenosis group compared with moderate group, t=-2.15, -4.86, -4.55, -4.26, -3.86, -3.71 and -3.39, all P<0.05). Conclusion3D-STI can be used for evaluation of segmental myocardial strains in patients with different stenosis of LAD and AS is a more sensitive parameter for detecting myocardial strain change in mild coronary stenosis.