【摘要】 目的评价斑点追踪成像技术(speckle tracking imaging,STI)的速度、位移和形变(应变及应变率)在检测2型糖尿病大鼠左心功能的灵敏性和应用价值。方法雄性SD大鼠按照30 mg/kg给予链脲佐菌素尾静脉注射后喂以高脂饲料,期间检测空腹血糖(fasting plasma glucose,FPG)及2 g/kg葡萄糖溶液灌胃2 h后的血糖(plasma glucose 2 h,PG2 h),以确定大鼠2型糖尿病模型建立成功;建模6周后用STI检测左心室6个不同节段收缩期、舒张期径向和周向速度、位移、形变(应变和应变率),并比较其变化情况。结果建模3周后,8只测得FPG>7.0 mmol/L和(或)PG2 h>11.1 mmol/L的大鼠被纳入模型组。建模6周后,STI分析显示模型组左心室收缩期和舒张期部分节段的径向、周向速度和位移较对照组显著降低,差异具统计学意义(P<0.05)。但左心室6个不同节段的收缩期和舒张期径向、周向整体速度,收缩期和舒张期径向、周向整体位移与对照组相比,差异均无统计学意义(P>0.05);形变分析显示模型组舒张期各节段径向、周向应变及其6节段的整体径向和周向应变,收缩期、舒张期径向整体应变率较对照组显著降低,差异有统计学意义(P<0.05)。结论 STI能够在早期检测到2型糖尿病大鼠左心室心肌部分节段收缩及舒张功能受损,采用形变参数评估心功能比速度和位移更为灵敏。更多还原

【Abstract】 Objectives To study the application of velocity, displacement and deformation by speckle tracking imaging( STI) in evaluation of left ventricular function in type 2 diabetic rats. Methods Male SD rats were injected with30 mg / kg streptozotocin through caudal vein and fed with high-fat diet. Fasting plasma glucose(FPG) and plasma glucose 2 h(PG2 h) were detected for confirmation of the success of establishing type 2 diabetic rat model. Systolic,diastolic radial and circumferential velocities, displacements and deformations(strains and strain rates) in 6 different segments of left ventricular wall were tested by STI in 6 weeks. Results A total of eight rats were included in type 2diabetic group with FPG>7.0 mmol / L and(or) PG2 h>11.1 mmol / L in 3 weeks. In 6 weeks, STI analysis showed significant reductions in systolic, diastolic radial and circumferential velocities and displacements in some of the segments when comparing diabetic group with control group(P <0.05); but no significant changes in the average systolic, diastolic radial and circumferential velocities and displacements were found(P>0.05). However, diastolic radial and circumferential stains in the 6 different segments, the average diastolic radial and circumferential stains in the 6different segments, the average systolic and diastolic radial stain rates significantly decreased in diabetic group compared to control group(P <0.05). Conclusions Left ventricular systolic and diastolic dysfunction can be detected by STI in early stage of type 2 diabetic rat model. Deformation is more sensitive in evaluation of left ventricular function than velocity and displacement.更多还原