Dynamic Survey The Model In Rabbits Of Pulmonary Artery Embolism With The Use Of Echocardiography

Objective: To compare the diagnostic value of conventional Echocardiography,Quantitative Tissue Velocity Imaging(QTVI) and Strain Rate Imaging(SRI) in appreciating right ventricle function in rabbits with pulmonary artery embolism and to observe the model of pulmonary artery embolism dynamically using these techniques. Methods: 21 healthy rabbits were enrolled in this study. Absorbable gelatin sponge were injected as embolia into Era-vein of rabbits to build the animal model of acute pulmonary embolism after one week normal feeding. The changes of right ventricle were observed immediately,1- week and 3- week after the model of pulmonary artery embolism was built.2-D image and QTVI image of 4-chamber view at cardiac apex were recorded. The results of conventional Echocardiography(internal diameter,pressure,velocity,heart function),Quantitative Tissue Velocity Imaging(QTVI) and Strain Rate Imaging(SRI) in different embolic phases were recorded . The model of pulmonary artery embolism were observed dynamically and at last the lung tissues were observed under microscope. Results: Right ventricular end diastolic diameter(RVDd),main pulmonary artery diameter(MPAD),right ventricular end diastolic area(RVAd),right ventricular end systolic area(RVAs),Tei index recorded immediately after the model was built and 1-week after the model was built increased comparing with those recorded before the model was built. Pulmonary Arterial Systolic Pressure(PSPA),the maximum velocity of pulmonary artery,Right Ventricle Proportion Changed Area (RVPCA),The peak velocity of systolic period (VP),The peak strain rate of early diastole(SRe),late diastole (SRa),the peak sustained systolic strain rate(SRs)reduced, the time interval of the onset of Q wave on electrocardiogram and the peak of systolic wave(TQ-S) prolonged .The changes observed immediately after the model was built were greater than those observed 1-week after the model was built. E/A>1 and Ve/Va>1 were found immediately after the embolism,while E/A<1 and Ve/Va<1 were found 1-week after embolism.RVDd,MPAD,RVAd,RVAs,RVPCA,SRe,SRa,SRs recorded 3-week after embolism have no statistical significance comparing with those recorded before the model was built. The PSPA,the maximum velocity of pulmonary artery acquired 3-week after embolism has no statistical significance comparing with that acquired 1-week after embolism. E /A<1 were found immediately after the model was built and 3-week after the model was built.VP recorded 3-week after embolism decreased slightly, TQ-S prolonged slightly, Tei index increased slightly comparing with that before embolism. The data obtained 3 weeks after embolism were near to that obtained before embolism, while the data obtained immediately after embolism and 1-week after embolism weren't. Ve/Va<1 were found three weeks after embolism.Conclusion: SRI had the same value to the indexes of conventional echocardiography in assessment of the right ventricle function in rabbits with pulmonary artery embolism. They showed the same change tendency. MVPA and QTVI have the same value in evaluation of the right ventricle function in rabbits with pulmonary artery embolism and they showed same change tendency. The right ventricle function were getting better gradually during the observation after pulmonary artery embolism. Vp,MVPA,TQ-S,Tei index didn't go back to normal at the end of three weeks, which manifested that the right ventricle still had the systolic and diastolic dysfunction.