二维应变成像技术评价糖尿病患者左心室收缩应变的跨壁阶差

Assessment of myocardial strain transmural gradient by 2-dimension strain imaging in the patients with type 2 diabetes

目的应用组织二维应变成像技术检测糖尿病患者左心室心肌内外膜层组织应变,评价左心室局部收缩功能的改变,为早期诊断及治疗糖尿病心肌病变提供依据。方法 2型糖尿病患者60例(无微血管病变组36例和微血管病变组24例)及对照组20例。常规超声心动图检测3组左心室射血分数及左心室心肌质量指数(LVMI)。取左心室乳头肌水平将室壁平均分为两层,即心内膜层和心外膜层。获取3组各节段心肌的纵向应变和圆周应变的峰值并进行对比分析。结果 3组间的左心室射血分数和收缩压无差异。3组各室壁节段心内膜层心肌收缩期峰值应变均高于心外膜层心肌(P<0.05)。糖尿病组患者的纵向应变峰值较对照组减低,微血管病变组较无微血管病变组减低(P<0.05)。糖尿病无微血管病变组较对照组圆周应变值增高,糖尿病微血管病变组圆周应变较无微血管病变组和对照组减低。微血管病变组较无微血管病变组和对照组应变值的跨壁阶差减低(P<0.05)。结论二维应变成像技术可早期检测出糖尿病患者内外膜层心肌应变跨壁阶差的变化,对于评价心肌局部收缩功能异常具有重要意义。

Objective To explore the characteristics of 2-dimension（2D） strain echocardiography of myocardial strain transmural gradient in assessment of left ventricle （LV） systolic dysfunction in patients with type 2 diabetes mellitus（T2DM）. Methods A total of 60 patients with T2DM were classified into two groups： group A （patients without microangiopathy, n=36）, and group B （patients with microangiopathy, n=24）, as well as 20 cases of age and gender matched healthy volunteers as the control group. The 2D strain analysis was carried out by defining the wall as a 2-layer structure with suitable regions of interest, subendocardial （endo） and subepicardial（epi） myocardium layers. The systolic longitudinal strain （SSL） and circumferential strain （SSC） measured from segments at the mid-level LV segments were analyzed offline respectively in the LV long-axis and short-axis views using 2D strain imaging. Results In spite of no significant differences in LV ejection fraction （EF） , systolic blood pressure among the three groups, the peak SSL significantly decreased in the T2DM groups compared with the control group （P0.05）. SSL in the T2DM group with microangiopathy was lower than the group without microangiopathy（P0.05）.In each group, strain was greater in the subendocardial than the subepicardial layer. The SSC of subendocardial layers in the T2DM groups without microangiopathy was higher than those in the control group （P0.05） . The SSC in the T2DM groups with microangiopathy was lower than the groups without microangiopathy （P0.05）. In T2DM groups with microangiopathy, the additional impairment of strain was greater in the endocardial than the epicardial layer. The stain transmural gradient in T2DM groups with microangiopathy was reduced more than those in other groups （P0.05）. Conclusion The 2D strain echocardiography is an accurate method to assess the gradient of transmural strain and may be a promising new tool for quantifying T2DM-induced regional myocardial dysfunction.