Assessment of myocardial microcirculation in diabetic rats using myocardial contrast echocardiography / 中华超声影像学杂志

ABSTRACT

Objective To investigate whether myocardial contrast echocardiography(MCE)combined with stress echocardiography could detect myocardial microcirculation disturbance of left ventricular(LV)in diabetic rats.Methods MCE were performed at rest and after dipyridamole infusion from parasternal shortaxis views at the papillary muscle level in DM rats(n=18,12 weeks later after STZ administration)and control rats(n=12).Regions of interest(ROI)were positioned with the anterior, lateral, posterior and septum walls.Plateau intensity(PI), initial slope of the curve(β)and time to PI(TTP)were obtained from the curve and myocardial blood flow(MBF)and myocardial flow reserve(MFR)was estimated.After the performance of MCE, myocardium was prepared for γ Well counting with ~(99m)Tc-MIBI and CD31 immunohistochemistry staining.Results There was no significant difference in MBF between the ROI of anterior, lateral, septum walls beyond posterior wall in each group at rest and after stress.MCE values from anterior wall were selected as the indexes for comparisons between the two groups.The PI., MBF and MFR in the DM group were significantly lower than those in the control group at rest and after stress(all P< 0.05).The β in the DM group was significantly lower and TTP was significantly longer after dipyridamole stress(P<0.05).The nuclide intake of myocardial tissue in different walls was similar in the DM group, but theY were all lower than those in the control group(P<0.05).The capillary density decreased significantly in the DM group compared with the control group.Conclusions The PI,β,TTP,MBF and MFR derived from MCE were all sensitive parameters in detecting the microcirculation disturbances in the earlier period of DM.