甲亢性心肌病兔血清cTn-I水平变化及其与心功能的相关性

Correlation of serum cardiac troponin and cardiac function of rabbits with hyperthyroid cardiomyopathy

目的探讨左心室不同构型的甲状腺功能亢进症(简称甲亢)性心肌病兔血清肌钙蛋白I(cTn-I)水平及其与心功能的相关性。方法对实验组兔(20只)腹腔注射左甲状腺素[45μg/(kg.d)×28d]建立甲亢动物模型,对照组兔(10只)每日腹腔注射生理盐水至实验结束。对两组兔行超声心动图检查,同时测定血清中cTn-I水平。实验组依据超声参数分为向心性肥厚(CH)亚组和离心性肥厚(EH)亚组。结果与对照组比较,CH亚组二尖瓣环平均舒张期峰值速度(Ve)减低(P<0.01),EH亚组二尖瓣环平均收缩期峰值速度(Vs)、Ve明显减低(P均<0.01)。CH亚组和EH亚组血清cTn-I水平明显高于对照组(P均<0.01),EH亚组较CH亚组血清cTn-I水平进一步升高(P<0.01)。cTn-I与Vs及Ve呈负相关(P均<0.01)。结论血清cTn-I浓度变化结合超声心动图可较敏感地反映甲亢性心肌病心肌损害的有无及其严重程度。

Objective To explore the correlation of serum cardiac troponin I（cTn-I） with cardiac function in different geometric patterns of left ventricle in rabbits with hyperthyroid cardiomyopathy.Methods Thirty New Zealand purebred rabbits were randomly divided into experimental group（n=20） and control group（n=10）.Hyperthyroidism models were established by peritoneal injection of levothyroxine（L-Thy） in experimental group.According to the changes of ultrasonic parameters,the ventricular geometries of experimental group were divided into concentric hypertrophy（CH） subgroup and eccentric hypertrophy（EH） subgroup.All rabbis underwent conventional echocardiogram and quantitative tissue velocity imaging（QTVI）,and cTn-I values were assesses.Results The average Ve was significantly lower in CH subgroup than that of the control group（P0.01）.The average Vs and Ve were significantly lower in EH subgroup than those of the control group（both P0.01）.The cTn-I in blood of CH subgroup was conspicuously higher than that of the control group（P0.01）.The cTn-I in blood of EH subgroup was conspicuously higher than that of the control group and CH subgroup（both P0.01）.Vs and Ve had negative correlation with cTn-I in blood.Conclusion It is a sensitive method to combine serum cTn-I with echocardiography to reflect myocardial perfusion of hyperthyroid cardiomyopathy in rabbits.