组织多普勒超声评价阿霉素诱导兔心肌病早期松弛功能改变的实验研究(英文)

Evaluation of tissue doppler echocardiography on detecting early myocardial relaxation abnormality in adriamycin-induced cardiomyopathy rabbits

目的:E/E’比值(二尖瓣血流舒张早期速度/二尖瓣环组织多普勒舒张早期速度)与左室充盈压有良好的相关性,可用来准确评价左室松弛功能异常。本研究利用该指标评价阿霉素所致兔心肌病心肌松弛功能的变化情况。方法:28只日本白兔分为2组:阿霉素组20只,每周静脉注射阿霉素2mg.kg-1,8周共计16 mg.kg-1以期形成心肌病模型;对照组8只,每周注射相同剂量的生理盐水。分别在第0、4、6、8、10、12周进行常规和组织多普勒超声心动图检查。结果:阿霉素组在10、12周左室内径显著扩大,左室射血分数和短轴缩短率显著下降(P<0.05)。显著变化最早发现在第10周。二尖瓣环处心肌组织收缩峰值速度在8、10、12周显著降低(P<0.05),显著变化最早发现在第8周。E/E’比值在6、8、10、12周显著增高(P<0.05),显著变化最早发现在第6周。对照组常规和组织多普勒超声指标均未发现显著变化(P>0.05)。结论:在阿霉素所致兔心肌病模型中心肌功能降低。E/E’变化早于组织多普勒收缩指标和常规超声心动图指标,为评价左室松弛功能提供了一个敏感可靠的新手段。

AIM： To evaluate myocardial relaxation function changes in an adriamycin-induced cardiomyopathy model using the transmitral flow velocity to mitral annular velocity ratio （E/E＇）, a strong positive relationship with left ventricular filling pressure and a good indicator for evaluating left ventricular diastolic relaxation abnormality. METHODS： Twenty-eight Japanese rabbits were divided into two groups. Adriamycin was administered at a dose of 2 mg· kg^-1 intravenous once a week for 8 weeks （total dose of 16 mg·kg^-1 ） in 20 rabbits to induce the cardiomyopathy model. 8 rabbits served as controls receiving the same amount of saline once a week for a total of 8 weeks. Conventional and tissue Doppler echocardiography （TDE） were performed at baseline, 4th, 6th, 8th, 10th and 12th week. RESULTS： In the adriamycin-treated group, LV chamber diameter significantly increased, while ejection fraction and fraction shortening significantly deereased in 10th and 12th week （P 〈0.05）. The significant changes were firstly found in 10th week. Mitral annulus systolic peak velocity （S＇） by TDE significantly decreased in 8th, 10th and 12th week （P 〈0.05）. The significant changes were firstly found in 8th week. The ratio of E/E＇ significantly increased in 6th, 8th, 10th and 12th week （P 〈 0.05）. The significant changes were firstly found in 6th week. In the control group, no significant changes were found in all parameter by tissue Doppler conventional eehocardiography （P 〉0.05）. CONCLUSION： Myocardial function is reduced in adriamycin-induced rabbit model of dilated cardiomyopathy. The relaxation parameter （E/E＇） by TDE changes is earlier than contraction indices S＇ by TDE and conventional echocardiography in adriamycin-induced cardiomyopathy rabbits, which provides a new sensitive and reliable method to evaluate LV relaxation function.