Evaluation Of Left Ventricular Systolic And Diastolic Function By Doppler Tissue Imaging In Patients With Type 2 Diabetes Mellitus

【Objectives】Doppler tissue imaging is an invasive technique which can quantify the direction, velocity and time of the myocardial movement. Compared with the conventional two dimensions and M-mode echocardiography. Doppler tissue imaging has higher sensitivity and more convenience in evaluating the myocardial ventricular movement. Diabetes mellitus is a definite risk factor of cardiovascular events. Diabetic cardiomyopathy is a kind of structural abnormality of myocytes resulting from Diabetes mellitus, characterized by comprehensive and diffuse myocardial interstitial fibrosis which ultimately leads to the ventricular hypertrophy, systolic and (or) diastolic dysfunction. The study aimed to investigate the velocity and the displacement of the mitral annulus, the myocardial diastolic and systolic peak strain rates of left ventricle segments in the patients with diabetes mellitus with quantitative tissue velocity ,strain rate and tracking imaging, and to investigate the clinical application of DTI in the evaluation of left ventricular diastolic function and the impact of hypertension on the cardiac structure and function in patients with type 2 diabetes.【Methods】Forty-two patients with type 2 diabetics who had no evidence of coronary artery disease confirmed by coronary angiography and 25 age- and sex-matched normal controls (NC) were enrolled. The diabetes patients were divided into normal blood pressure group (DM, n=20) and hypertension group (DM+HT, n=22). All the patients underwent Doppler echocardiography at rest. Early diastolic peak velocity of the mitral annulus and long axis myocardial peak strain rates of left ventricle segment together with parameters of mitral inflow profile were measured with quantitative tissue velocity and strain rate imaging.1.Conventional two dimension ultrasound: to measure the IVSTd, LVPWTd, LVEDD, LVMI and LVEF are counted by the Penn-Cube formula and adjusted Simposon equation respectively.2.The mitral and aortic value inflow:to measure E, A, EDT, PEP, LVET, ICT and IVRT.3.Tissue Velocity Imaging (TVI): to measure Sa, Ea, Aa, Da, Sm, Em, Am, Dm, SRs, SRe and SRa.【Results】1.The PEP and the ration of PEP and LVET increased in the diabetic groups(P < 0.05). In addition, there were significant differences in PEP/LVET, LVMI, FS, A and E/A between diabetes combined hypertension group and control group.2.There were significant differences in Ea, Ea/Aa, E/Ea and SRe between diabetic groups and control group. Diabetes combined hypertension group had much lower Em of ventricular apex and middle segments and SRa of ventricular apex segment than control group.3.The Dm and SRs of left ventricular basic segment in diabetic group dramatically increased. The diabetes combined hypertension group had much lower Dm of middle ventricular segment than the control group. Meanwhile, the diabetes combined hypertension group had much lower SRs of middle ventricular segment than the control group and isolated diabetic group.【Conclusions】1.The strain rate and tissue Doppler imaging can detect the early impairment of cardiac diastolic function in the patients with diabetes at rest, contributing to the early diagnosis of diabetes cardiomyopathy.2.The strain rate and tissue tracking are sensitive and liable to evaluate the early local cardiac systolic function in the patients with diabetes mellitus, providing an invasive method to detect early cardiac systolic dysfunction.3.The glucose metabolic dysfunction and the increase of pressure load exacerbate the left ventricular hypertrophy and impairment of heart function in the patients with diabetes mellitus combined hypertension.