二维应变技术对未重构高血压患者心肌收缩功能的研究

Assessment of non-left ventricular hypertrophy systolic function in patients with hypertension using two-dimensional strain in echocardiography

目的将二维应变技术应用于左心室心肌未重构的原发性高血压患者,探讨其评价左心室心肌长轴方向收缩功能的临床应用价值。方法应用常规超声计算左心室质量指数和相对室壁厚度,选取30例左心室心肌无重构的1-2级高血压患者,及30名健康者做健康对照组,分别采集心尖左心室长轴切面、心尖四腔心切面、心尖两腔心切面的二维动态图,运用二维应变技术,获取左心室18个节段收缩期峰值应变的牛眼图,及左心室3个心尖切面及整体的全局收缩期峰值应变值,并对室壁应变梯度进行分类比较。结果高血压组左心室3个心尖切面及整体的全局收缩期峰值应变值略降低,但不具有统计学意义(P>0.05)。而高血压组基底段的平均收缩期峰值应变明显低于健康对照组[(-16.98±5.60)%,(-19.29±2.68)%,t=-4.072,P=0.000];高血压组室间隔和前壁基底段应变分别为(-14.30±3.54)%、(-14.60±4.35)%,健康对照组的分别为(-18.40±2.30)%、(-19.15±2.37),两组比较差异有统计学意义(t=-4.341、-4.112,P均=0.000);高血压组侧壁和前壁中间段应变分别为(17.45±4.86)%、(-17.95±3.00)%,健康对照组的分别为(-20.25±2.94)%、(-21.70±2.96)%,两组比较差异有统计学意义(t=-2.205、-3.981,P=0.034、0.000);高血压组侧壁和前壁平均应变分别为(-19.15±6.68)%、(-19.37±6.10)%,健康对照组的分别为(-21.47±4.05)%、(-22.58±4.41)%,两组比较差异有统计学意义(t=-2.298、-3.312,P=0.024、0.001)。高血压组不完全逆梯度和完全逆梯度的室壁比例较健康对照组明显增高,达到18%和5%。结论二维应变技术能够在未重构高血压患者左心室整体收缩功能出现明显异常前,显示出部分室壁及心肌节段的收缩功能降低,并可对心肌节段的收缩功能进行定量、定位分析;局部收缩功能的降低考虑与高血压引起心纤维环弹性降低和应变梯度的改变有关。

Objective To evaluate the non-left ventricular hypertrophy(NLVH)longitudinal systolic function in patients with primary hypertension using two-dimensional strain in echocardiography.Methods According to the left ventricular mass index(LVMI)and relative wall thick(RWT),30 patients with hypertension were chosen and 30 normal control subjects,who were determined by transthoracic echocardiography in routine parameters.Height frame rate two-dimensional images were recorded from the apical four-chamber view,two-chamber view and long-axis of the left ventricle.The peak systolic longitudinal strain of 18 segments and 3 whole views were measured using two-dimensional strain software,and eventually the strain of 18 segments were showed in a Bull's eye,and compared wall strain gradient with classification.Results No significant difference in the peak systolic longitudinal strain of 3 whole views were found between the control group and NLVH group.However,the average peak systolic longitudinal strain of base segments were significantly different in the NLVH group compared with the control group [(-16.98±5.60)%,(-19.29±2.68)%,t=-4.072,P=0.000],The peak systolic longitudinal strain of some segments and walls in the NLVH group were significantly lower than those in the control group,for example,the basal segment of septal and anterior[(-14.30±3.54)%,(-18.40±2.30)%,t=-4.341,P=0.000);the basal segment of[(-14.60±4.35)%,(-19.15±2.37)%,t=-4.112,P=0.000);the middle segment of side[(17.45±4.86)%,(-20.25±2.94)%,t=-2.205,P=0.034)];the middle segment of anterior[(-17.95±3.00)%,(-21.70±2.96)%,t=-3.981,P=0.000];side[(-19.15±6.68)%,(-21.47±4.05)%,t=-2.298,P=0.024];Anterior[(-19.37±6.10)%,(-22.58±4.41)%,t=-3.312,P=0.001)。The part of counter-gradient and completely counter-gradient of the wall ratio in NLVH group were significantly higher than the control group,reaching 18% and 5%.Conclusions Two-dimensional strain in echocardiography can show the decline of systolic function in part of the wall and the myocardial segments before the global systolic function in patients with primary hypertension,and give them positioning and quantitative analysis.The decline of local systolic function is related to the reducing of resilience in fibrous ring of heart and the change of strain gradient which arosed by hypertension.