超声斑点追踪成像技术评价甲状腺功能亢进性心肌病兔不同左室构型心肌收缩功能的变化

摘要

Objective To evaluate the left ventricle systolic function of different geometic patterns in rabbits with hyperthyroid cardiomyopathy by speckle tracking echocardiography(STE). Methods Thirty New Zealand purebred rabbits were randomly divided into two groups:control group (n=10) and experimental group (n = 20). Hyperthyroid-ism animal model was established by peritoneal injection of Levothyroxine (L-Thy) in experimental group. According to the ultrasound parameter changes, the ventricular geometries of experimental group were divided into two groups: concentric hypertrophy (CH) and eccentric hypertrophyCEH). Curves and peak values of systolic radial strain (RS) and circumferential strain (CS) were obtained by STE and conventional echographic parameters were also obtained. Results In CH group the LVMI.RWT increased obviously(P<0. 01). In EH group the LVMI increased obviously (P<0. 01) ,but RWT was not change significantly (P>0. 05). EF and FS were significantly lower in EH group than those of the control group (P<0. 01). CS decreased significantly in anteroseptal,anteriorand inferoseptal segments of CH group (P<0. 01,P<0. 05) .RS decreased significantly in anteroseptal and anterior segments of CH group (P< 0. 01). SR and CS curves of EH group were disordered,and RS or CS peak strain values was evidently lower than that in the controls (P<0. 01). Conclusions STE can assess accurately the left ventricle systolic function of different geometic patterns in rabbits with hyperthyroid cardiomyopathy.%目的 探讨超声斑点追踪成像(STE)评价甲状腺功能亢进(甲亢)性心肌病兔不同左室构型局部心肌收缩功能变化的价值.方法 新西兰纯种白兔30只,随机分为实验组(20只)和对照组(10只).实验组腹腔注射左旋甲状腺素[45 μg/ (kg·d)],共28 d,建立甲亢动物模型,实验组依据超声参数分为两型:向心性肥厚组(CH组)和离心性肥厚组(EH组),各组均行常规超声及STE参数测定,包括:左心室短轴乳头肌水平各节段径向应变(RS)和周向应变(CS)值.结果 CH组左室质量指数(LVMI)及相对室壁厚度(RWT)明显增加(P＜0.01)；LVEF、FS与对照组比较差别无统计学意义(P＞0.05).EH组左室质量指数(LVMI)明显增加(P＜0.01),而相对室壁厚度(RWT)与对照组比较差别无统计学意义(P＞0.05)；LVEF、FS与对照组比较明显减低(P＜0.01).CH组与对照组比较,左室乳头肌水平前间隔、前壁、后间隔的CS值及前间隔和前壁的RS值明显减低变,差异有统计学意义(P＜0.01); EH组与对照组比较,左室乳头肌水平RS及CS曲线紊乱,各节段RS及CS值均明显减低(P＜0.01).结论 STE能准确评估甲亢性心肌病兔不同左室构型局部心肌收缩功能的变化.