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To evaluate the relationship between atherosclerosis and hemodynamic of coronary artery in mice detecting by ultrasound bio‐microscopy flow imaging . Methods Double 14 20‐week‐old LDL‐R‐/‐and C57BL/6 male mice were selected ,and randomly divided into two groups in each genotype according to weight . Each two groups were fed to 28 weeks or 36 weeks age respectively with west diet . Coronary artery hemodynamics in these mice were assessed in vivo by Vevo ?2100 ultrasound imaging system ,then the intima‐media thickness( IM T ) of aorta in histopathology were analyzed . T he differences of coronary artery hemodynamic parameters such as maximum velocity ( Vmax ) ,mean velocity ( Vmean) and velocity time integral ( V T I) were compared between mice of different genotypes of the same week and mice of different weeks of the same genotype . And the relationship between coronary artery hemodynamic in ultrasound and aortic IM T in histopathology were analyzed . Results ① All coronary hemodynamic parameters in LDL‐R‐/‐ mice were significantly lower than those of wild‐type mice except the Vmax between two 28‐week‐old genotypes group at the same weeks of age of different genotypes ( all P ＜0 .05) . But there was no significant difference in coronary artery hemodynamic parameters between mice of the same genotype at different weeks of age( P ＞0 .05) . ②T he histopathological measurements of aortic IM T in LDL‐R‐/‐mice were significantly higher than those of wild type mice ( all P ＜ 0 .05 ) ,and those of 36‐week‐old mice were significantly higher than those of 28‐week‐old mice ( all P ＜ 0 .05 ) . ③ All coronary hemodynamic parameters such as Vmax ,Vmean and V TI were negatively correlated with pathological measurements of aortic IM T ( r ＝ －0 .532 , －0 .423 , －0 .524 ; all P ＜ 0 .05 ) . Conclusions The parameters of coronary artery hemodynamics obtained by ultrasound bio‐microscopy are well correlated with the pathological results of atherosclerosis . Ultrasound bio‐microscopic flow imaging can be used as a new method to evaluate the degree of atherosclerosis in mice by detecting the hemodynamic parameters of coronary artery .
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Objective Some children with congenital heart defect would get serious acute respiratory distress syndrome in ICU postoperatively,which is a tough problem.We summarized the clinical effects of synchronized intermittent mandatory ventilation (SIMV)with expiratory high frequency ventilation (HFV) for these patients in our center.Methods A total of 13 pediatric patients,with(8.15 ±4.34)months old and (8.23 ±4.01 )kg weight,used SIMV with expiratory HFV from Jan 2012 to Aug 2013.Keeping the original SIMV conditions unchanged,the expiratory oscillation amplitude were 25 to 35 Ann(A)and the oscillation frequency of 7 to 9 hertz(Hz).All patients were divided into two groups to oxygenation index(OI)30 min before HFV,high OI group(OI≤20,n ﹦5)and low OI group(OI 〈20,n ﹦8).OI ﹦MAP ×FiO2 /PaO2 .The values of OI,PaO2 /FiO2 and PaCO2 of two groups were monitored before and at 2,6,24,48 h after HFV re-spectively.Results The values of OI of all 13 patients were 19.31 ±4.42 before HFV,and then decreased to 18.77 ±5.18,16.00 ±5.22,14.77 ±6.56,and 13.92 ±6.53 respectively at 2,6,24 and 48 hours later (P 〈0.01 ).But there was no significant difference of OI in high OI group in different time points.The val-ues of PaCO2 of all 13 patients were(43.46 ±5.67)mmHg(1 mmHg ﹦0.133 kPa)before HFV,and de-creased to(38.31 ±4.21)mmHg,(37.61 ±3.36)mmHg,(34.77 ±3.81 )mmHg,and(35.92 ±2.39)mmHg respectively at 2,6,24,and 48 hours after HFV(P 〈0.01 ).Three dead patients were all in high OI group. Conclusion The mortality rate of serious acute respiratory distress syndrome with congenital heart diseases postoperatively is high.SIMV with expiratory HFV can improve oxygenation and reduce carbon dioxide,and the effect is better when OI 〈20.