超声定量组织速度显像评价兔扩张型心肌病模型左心室收缩功能的应用价值

目的 探讨超声定量组织速度显像(QTVI)技术评价兔扩张型心肌病(DCM)模型制备前、后左室收缩功能的应用价值.方法 30只日本大耳白兔,随机分为两组.阿霉素组(A组)20只,经耳缘静脉注射阿霉素2 mg/kg,每周1次,连续8周,总剂量为16 mg/kg.生理盐水组(B组)10只,同时间给予同剂量的生理盐水.于给药前、后分别行超声心动图检查,获取心脏房室腔大小、左室射血分数等常规参数以及QTVI参数,包括收缩期峰值速度(Vs)及峰值位移(D).结果 ①A组兔给药后,房室腔增大,左室射血分数、短轴缩短率降低,与给药前比较,差异具有统计学意义(P<0.05,P<0.01);心肌组织速度曲线及位移曲线仍呈规律性,但Vs、D值减低,差异有统计学意义(P<0.05,P<0.01);②B组兔注射前、后比较各常规参数差异无统计学意义(P>0.05);心肌组织速度曲线及位移曲线波形规则,Vs值及D值由心底至心尖依次递减;③病理显示A组兔呈DCM样改变,B组兔无明显变化.结论 QTVI可准确评价兔DCM模型前、后左室心肌收缩功能,为DCM的临床观察、治疗提供实验依据.

Assessment of left ventricular systolic function in dilated cardiomyopathy rabbits by quantitative tissue velocity imaging

Objective To quantitatively assess left ventricular systolic function in rabbits with dilated cardiomyopathy(DCM) by quantitative tissue velocity imaging (QTVI). Methods Thirty rabbits were divided into two groups: group A(adriamycin group) and group B(sodium chloride group). Group A( n = 20) were given adriamycin 2 mg/kg intravenously once a week for eight weeks (total dose, 16 mg/kg) to induce DCM model, group B were given with the same dose of sodium chloride injection solution. Two dimensional echocardiography and QTVI examination were performed in all rabbits before and three weeks after the administration,respectively. Peak systolic velocity(Vs), peak displacement(D) and other common parameters were analyzed. Results Common parameters assessed after administration in group B did not show significant changes. The QTVI curves of left ventricle myocardium were regular and the value of Vs and D decreased gradually from the basal segments to the apical segments after the administration. The diameters of atrium and ventricle of group A increased,while the ejection fraction and fractional shortening of left ventricle decreased significantly ( P <0. 05 or P < 0.01). The pattern of the curves still had the regularity. But Vs and D value decreased significantly ( P <0. 05 or P <0. 01). Pathology of myocardium samples of group A showed the cardiomyocyte changes like dilated cardiomyopathy, while samples of group B had no significant change. Conclusions QTVI can accurately evaluate regional systolic function of left ventricle in rabbits with dilated cardiomyopathy, therefore provides experimental foundation for clinical observation and treatment.