超声评价甲亢性心肌病不同左室构型兔腹主动脉剪切力的变化

Evaluation of the changes of fluid shear stress of abdominal aorta in hyperthyroid cardiomyopathy rabbits with different left ventricular geometric patterns by high frequency ultrasonography

目的探讨超声在评价甲亢性心肌病左室不同构型兔腹主动脉剪切力变化中的价值。方法新西兰大白兔30只,分为对照组10只和实验组20只。实验组建立甲亢模型,依据超声观测左室构型情况分为向心性肥厚7只(CH组)和离心性肥厚11只(EH组)。应用M型超声测量左室舒张末期内径(LVDd)、室间隔厚度(IVSTd)、左室后壁厚度(PWTd)、左室射血分数(LVEF)和短轴缩短率(FS),计算左室质量指数(LVMI)和相对室壁厚度(RWT)。应用脉冲多普勒测量兔腹主动脉内径、峰值血流速度、平均血流速度及血液黏稠度,计算血流剪切力。结果与对照组比较,CH组IVSTd、PWTd、RWT及LVMI均增加,EH组LVDd、IVSTd、PWTd及LVMI增加,而LVEF、FS均减低(均P<0.05)。与CH组比较,EH组LVDd、LVMI增大,而RWT、LVEF、FS减低(均P<0.05)。与对照组比较,CH组和EH组腹主动脉内径、峰值血流速度、平均血流速度、血液黏稠度及血流剪切力均升高(均P<0.05)。与CH组比较,EH组峰值血流速度、平均血流速度及血流剪切力均升高(均P<0.05)。结论超声能够有效地评价甲亢性心肌病不同左室构型兔腹主动脉剪切力的变化。

Objective To evaluate the changes of fluid shear stress of abdominal aorta in hyperthyroid cardiomyopathy rabbits with different left ventricular geometric patterns by ultrasonography. Methods Thirty purebred New Zealand rabbits were divided into control group （n=10） and experimental group （n=20）.Hyperthyroidism animal model was established by peritoneal injection of Levothyroxine in exprimental rabbits, and they were divided into concentric hypertrophy （CH group,n=7） and ecconcentric hypertrophy（EH group,n=11） according to the ultrasound parameter changes of the left ventricular geometric patterns. The left ventricular end diastolic diameter（LVDd）, interventricular septum thickness （IVSTd）,left ventricular posterior walt thickness（PWTd）, left ventricular ejection fraction（LVEF） and short axial shortening rate（FS）,the left ventricular mass index（LVMI） and relative wall thickness（RWT） were measured and calculated by ultrasonography.The diameters of abdominal aorta,peak velocity,mean velocity,blood viscosity and abdominal aorta fluid shear stress were measured and calculated by ultrasonography. Results Compared with control group,the IVSTd,PWTd,LVMI and RWT increased in CH group ,the LVDd,IVSTd,PWTd and LVMI increased,LVEF and FS decreased in EH group （all P〈0.05）.Compared with CH group,the LVM1 and LVDd increased,RWT,LVEF and FS decreased in EH group （all P〈0.05）. Compared with control group,the diameters of abdominal aorta, peak velocity, mean velocity, blood viscosity and fluid shear stress increased in CH group and EH group （all P〈0.05 ）. Compared with CH group,the peak velocity, mean velocity and abdominal aorta fluid shear stress increased in EH group （all P〈0.05）. Conclusion Ultrasonography can efficiently assess the changes of abdominal aorta fluid shear stress in hyperthyroid cardiomyopathy rabbits with different left ventrieular geometric patterns.