Tissue Doppler echocardiography detecting early myocardial relaxation abnormality in Adriamycin-induced cardiomyopathy rabbits
FEI Hong-wen1, WANG Xin-fang2, XIE Ming-xing2, HE Ya-le1
1. Department of Cardiology, Guangdong Provincial Cardiovascular Institute, Guangdong Provincial People’s Hospital, Guangzhou 510100, China; 2. Department of Ultrasound, Union Hospital, Tongji Medical College,Huazhong University of Science and Technology, Wuhan 430022, China
Abstract：Objective: Transmitral flow velocity to mitral annular velocity ratio(E/E’) had a strong positive relationship with left ventricular filling pressure, which presents as a good indicator for evaluating left ventricular diastolic relaxation abnormality. The present study was designed to evaluate myocardial relaxation function changes in an Adriamycin-induced cardiomyopathy model using E/E’. Methods: Twenty-eight Japanese rabbits were divided into two groups. Adriamycin was administered intravenously at a dose of 2mg/kg once a week for 8 weeks(total dose 16mg/kg) in 20 rabbits to induce the cardiomyopathy model. Eight rabbits served as controls receiving the same amount of saline once a week for a total of 8 weeks. Conventional and tissue Doppler echocardiography were performed at baseline, 4th week, 6th week, 8th week, 10th week, 12th week. Results: In the Adriamycin-treated group, LV chamber diameter significantly increased, while ejection fraction and fraction shortening decreased significantly in the 10th and 12th week(P<0.05). The significant changes were first found in the 10th week. Mitral annulus systolic peak velocity by TDE decreased significantly in the 8th, 10th and 12th week(P<0.05). The significant changes were first found in the 8th week. The ratio of E/E’ significantly increased in the 6th, 8th, 10th and 12th week(P<0.05). The significant changes were first found in the 6th week. In the control group, no significant changes were found in all parameters by tissue Doppler, conventional echocardiography(P>0.05). Conclusions: Myocardial function was reduced in Adriamycin-induced rabbit model of dilated cardiomyopathy. The relaxation parameter(E/E’) by TDE changed earlier than contraction indices by TDE and conventional echocardiography in Adriamycin-induced cardiomyopathy rabbits, which provide a new sensitive and reliable method to evaluate LV relaxation function.
2006, Vol. 17 
