Relationship between myocardial perfusion impairment and dysfunction in diabetic rats using myocardial contrast echocardiography and velocity vector imaging

Abstract

Objective To investigate whether myocardial dysfunction and perfusion impairment had happened in diabetes mellitus(DM)rats,and to assess the relationship between them by using myocardial contrast echocardiography(MCE)and velocity vector imaging(VVI).Methods MCE and VVI were performed from the short-axis views of the mid-left ventricular level both at rest and after dipyridamole stress in control rats and DM rafs(12 weeks after induction with streptozotocin).MCE-derived myocardial blood flow(MBF)and myocardial flow reserve(MFR)and VVI-derived circumferential strain rate(SRc)and SRc reserve were obtained.Results SRc(absolute value)and MBF in the DM group were significantly lower than those in the control group at rest(P =0.03 for SRc and P =0.005 for MBF).SRc reserve and MFR in the DM group were significantly lower than those in the control group after dipyridamole stress (P =0.000 for SRc reserve and P =0.014 for MFR).There was no significant correlation between SRc and MBF at rest in the DM group(r =0.189,P =0.453).However,significant negative correlation existed between SRc reserve and MFR(r =-0.658,P =0.003).Conclusions Both myocardial systolic function and perfusion are impaired in DM rats.The decrease of MBF might not be the predominant determinant of myocardial systolic dysfunction at rest.However,the impairment of MFR could be an important contributor to the decrease of myocardial contractile reserve. Key words: Echocardiography,stress; Microbubbles; Diabetes mellitus; Ventricular function,left; Dipyridamole; Velocity vector imaging