Objective To assess the left ventricular(LV) regional myocardial systolic function after bone marrow mesenchymal stem cells (BMSCs) injection in rabbits with acute myocardial infarction(AMI) by 2-dimensional ultrasound speckle-tracking imaging.Methods Twenty-four healthy rabbits were randomly divided into three groups:group of sham-operated,group of masculine control (AMI was induced by ligation of left anterior descending coronary artery),and group of cell infusion(after two weeks of AMI,bone marrow mesenchymal stem cells were injected to the region of AMI).Four weeks after cell deliver two-dimensional strain images were acquired from LV short-axis view(at the levels of mitral annulus,muscle papillary and apex),radial strain rate (SrR),circumference strain rate (SrC),rotation rate (RotR) and rotation (Rot) of three levels in short-axis views were measured by speckle-tracking imaging.The conventional echocardiography indices included LV diameter of end diastole(LVEDd),LV ejection fraction(LVEF),LV fractional shortening(LVFS).The catheter indices included LV systolic pressure(LVSP),LV end diastolic pressure (LVEDP)and maximum rate of rise and descend of LV pressure(LVdp/dtmax).ResultsCompared with sham-operated group,rabbits had significantly larger LVEDd,lower LVEF and LVFS,lower LVSP and LVdp/dtmax,higher LVEDP in control group,SrR,SrC,RotR and Rot of LV anterior regional myocardial function and global myocardial function of three levels in short-axis views were lower.Compared with control group,the rabbits had significantly smaller LVEDd,larger LVEF and LVFS,larger LVSP and LVdp/dtmax,lower LVEDP,SrR,SrC,RotR and Rot of LV anterior regional myocardial function and global myocardial function of three levels in short-axis views were larger in group of cell infusion.There was no significant between group of cell infusion and group of sham-operated.Conclusions Speckle tracking imaging can evaluate the regional myocardial systolic function of the area of BMSCs transplantation accurately.

Objective To investigate the application of parametric quantification (PQ) with targeted microbubbles on angiogenesis after stem cell transplantation in rabbits with myocardial infarction.Methods A CD34-targeted microbubble was prepared.Acute myocardial infarction (AMI) model were established by ligating coronary artery in 80 New Zealand white rabbits.Rabbits in common microbubble group (T + C group) and CD34-targeted microbubble group (T + T group) were subjected to myocardial contrast echocardiography(MCE),then compare myocardial perfusion parameters (A,β and A × β values) pre- and 3d post- ligation and 4 weeks after stem cell transplantation.Microvessel density (MVD) were determine by CD34 antibody immunohistochemistry.Results Compared to before stem cell transplantation,the perfusion scores ( P ＜0.05) and A,β and A× β values( P ＜0.01) of T+ C group and T+ T group were increased than before transplantation and control group.MVDs after stem cell transplantation in experimental groups were higher than those of control group ( P ＜0.01),especially the T + T group.A × β value in the T + C group was correlated with MVD ( r =0.658,P ＜ 0.05) ; β and A × β value in the T + T group were correlated with MVD ( r =0.620,0.859,P ＜0.05).A × β value ( X ) and MVD ( Y ) were included to establish the following regression equation:Y =- 130.986 + 34.505 X ( R 2 =0.556,P ＜ 0.05).Conclusions PQ and CD34-targeted microbubble probably provides some value in invasive evaluation of angiogenesis after stem cell transplantation.