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Objective:To investigate the relationship between vulnerability of mouse coronary artery plaque and downstream myocardial perfusion and myocardial strain.Methods:Thirteen ApoE knockout mice with stable coronary plaques (stable plaque group)and 13 ApoE knockout mice with vulnerable coronary plaques(vulnerable plaque group) were selected as the experimental group, and 15 sex- and age-matched C57BL/6 mice with the same genetic background as ApoE mice were chosed as the control group. Myocardial contrast echocardiography (MCE) was carried out to quantify regional myocardial perfusion at rest and during adenosine stress using a Vevo 2100 system (Visual sonics). Replenishment curves of myocardial contrast were obtained, and rates of signal rise (β) and plateau intensity (A) were recorded. MBF was estimated by the product of A and β. Speckle tracking imaging combined with adenosine stress test was used to evaluate the longitudinal strain of left ventricular myocardium in mice. The vulnerability of the plaque was assessed by histopathology in serial tissue sections of proximal and middle left coronary artery according to the previously reported method.Results:There were no significant differences in body weight, heart rate, left ventricular end diastolic volume, left ventricular end systolic volume, left ventricular mass and ejection fraction among the three groups( P>0.05). The levels of serum triglyceride, total cholesterol, high density lipoprotein and low density lipoprotein in stable plaque group and vulnerable plaque group were significantly increased when compared with those in control group (all P<0.05). The pathological results showed that the coronary luminal stenosis rates in the stable plaque group and the vulnerable plaque group were (74.3±4.9)% and (75.5±7.1)% respectively, with no significant difference between the two groups( P>0.05). MBF of the middle anterior septum and left ventricular posterior wall in the experimental groups were significantly decreased when compared with that in the control group both in the resting status and during adenosine stress(all P<0.05). There were no significant differences in the MCE parameters between the stable plaque group and the vulnerable plaque group at rest( P>0.05). However, during adenosine stress, MBF of the vulnerable plaque group was decreased more significantly than that of the stable plaque group ( P<0.05). Compared with the control group, the values of longitudinal strain of the left ventricle in both experimental groups were decreased during resting status, without statistical significance (all P>0.05), but decreased significantly during adenosine stress and with more decrease in the vulnerable plaque group (all P<0.05). Conclusions:For the same degree of coronary artery stenosis in mice, the coronary artery vulnerable plaque group has less downstream myocardial perfusion and myocardial strain than the stable plaque group during adenosine stress. That is, the plaque vulnerability can affect the downstream myocardial perfusion and myocardial strain in the mouse model.
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Objective To explore the effects of adenosine stress on myocardial perfusion in healthy mice by myocardial contrast echocardiography ( MCE) . Methods MCE was carried out to quantify regional myocardial perfusion at rest and during adenosine stress using a VEVO 2100 system in 26 C57BL/6 mice . Echocardiography images from standardized parasternal long axis and short axis at papillary muscle level were consecutively acquired in real‐time . All dynamic images were recorded for off‐line analysis . Left ventricular myocardial perfusion quantitative parameters were acquired both under resting status and during adenosine stress . Replenishment curves of myocardial contrast were obtained and myocardial blood flow ( MBF) was calculated . Results Twenty‐six experimental animals successfully underwent MCE before and during adenosine stress . T here was no significant difference in heart rate ,left ventricular structure and functional parameters before and during adenosine stress ( all P ＞0 .05) . Rates of signal rise β values which were used to estimate blood velocity of middle anterior septum and posterior wall in left ventricular long‐axis view and anterior wall ,lateral wall ,inferior wall and septal wall in short‐axis view at papillary muscle increased significantly during stress compared with those at rest ( all P ＜0 .05 ) . T here was no significant difference in the plateau intensity A values( all P ＞0 .05 ) . T he MBF in each segment of the myocardium increased significantly during stress compared with those in resting state ( all P ＜0 .05) . Conclusions T he physiological characteristics of myocardial perfusion in mice before and during adenosine stress were preliminarily obtained ,w hich provided a basis for the application of adenosine stress echocardiography in cardiovascular disease models such as coronary heart disease in mice .
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Objective To explore the effects of adenosine stress on myocardial strain in healthy mice by speckle tracking imaging (STI).Methods A high-resolution rodent ultrasound machine Vevo 2100 was used to perform conventional transthoracic echocardiography at baseline and after intravenous infusion of adenosine in 34 C57BL/6 mice.Echocardiography images from standardized parasternal long axis and short axis at papillary muscle level were consecutively acquired in real-time.All dynamic images were recorded for off-line analysis.Left ventricular myocardial mechanical strain parameters were acquired both under resting status and during adenosine stress.Results Thirty-four experimental animals successfully underwent STI before and during adenosine stress. There was no significant difference in heart rate,left ventricular structure and functional parameters between before and after the adenosine stress ( P >0.05).Global peak longitudinal strain value in left ventricular long-axis view was significantly increased during stress compared with those at resting status ( P < 0.05);while there was no significant increase in the global peak circumferential strain and global peak radial strain values in short-axis view at papillary muscle ( P >0.05).Conclusions Myocardial strain is obtained in healthy mice before and after adenosine stress.This provides an evidence to the application of stress echocardiography in mice with coronary heart disease or other cardiovascular disease in the future.
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Objective To assess the reproducibility of contrast-enhanced echocardiography and conventional echocardiography for measurements of left ventricular ejection fraction(LVEF) and left ventricular volume in patients undergoing cancer chemotherapy. Methods One hundred and two patients undergoing cancer chemotherapy were divided into satisfactory image group(36 subjects) and unsatisfactory image group(66 subjects) according to the quality of the recorded images.High frame rate two-dimensional and three-dimensional images were recorded from apical long-axis view,four-chamber view and two-chamber view of left ventricle. Contrast-enhanced echocardiography was performed in the unsatisfactory image group.Two equally experienced examiners measured the LVEF and left ventricular volume in all patients by EchoPac software. Results The reproducibilities of Simpson′s biplane method and 3D full-volume echocardiography were low for measurements of LVEF in unsatisfactory image group ( P < 0.01).But they were improved significantly with contrast-enhanced echocardiography ( P > 0.05 ). The reproducibilities of Simpson′s biplane method and 3D full-volume echocardiography for measurements of left ventricular end-diastolic volume in unsatisfactory image group were also improved by performing contrast-enhanced echocardiography ( P > 0.05). The reproducibilities for measurements of left ventricular end-systolic volume were well in both group.Conclusions The reproducibilities for measurements of LVEF and left ventricular volume are improved in patients undergoing cancer chemotherapy with unsatisfactory images by using contrast-enhanced echocardiography.
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Objective To solve the problem of the skin resource and skin quality after excision of skin scar and other lesions to a certain extent. Methods Using the skin external expander that was designed and developed by the authors, we expanded skin at the given time and quantity. Results 28 patients had received the treatment, and they all had a large proportion of skin-scard. Obviously their skin-scar was eliminated throughly after using the skin external expander and commissure being hooked in. These 28 cases have shown that there would be no chance for the patients to suffer from hyperplastic akin-scard after their first stage of treatment. Conclusion The skin external expander is really a new method to solve the problem of the skin resource and skin quality after exscinding skin scar and other lesions to a certain extent.