Subclinical Left Ventricular Longitudinal Systolic Function In Patients With Diabetes Mellitus Before And After Controlling Blood Glucose Quantitatively By Velocity Vector Imaging

Background:Diabetes mellitus (DM) is a chronic metabolic syndrome characterized by a long-term persistent hyperglycemia.DM can lead to multiple system damage, and the cardiovascular complications have gradually become one of the major causes of death in patients with diabetes. Along with the improvement of people’s living standard and the changing in the life style, DM in China particularly the type2was rising. To improve the prognosis and life quality of patients, lower fatality, it is very important to diagnose and treat early. Diabetic cardiomyopathy shows overall and local decreasing cardiac function.But the conventional two-dimensional echocardiography can not accurately reflect subclinical myocardial function changes. Recently developed new technique-velocity vector imaging (VVI) which based on the tracing technology could estimate the changes of regional myocardial movement accurately and sensitively. It has been less reports of subclinical left ventricular systolic function in patients with diabetes mellitus by VVI technology at home and abroad.Objective:To investigate the subclinical left ventricular systolic function in patients with type2DM by VVI. To characterize the regularity of left ventricular longitudinal function in type2DM patients before and after treatment. To discuss the important clinical value of VVI in quantitatively evaluating regional longitudinal function of left ventricle in type2DM patients.Methods:60patients who visited Endocrine Research Institute in our hospital from October,2010to November,2011. All the patients were diagnosed type2Diabetes mellitus (2-DM) and underwent observation and treatment for nine months. All the patients were divided into two groups:patients with pure2-DM30cases, patients both with2-DM and hypertension (2-DM&HP)30cases. Control group included40healthy subjects with normal X-ray and routine echocardiography test, without history of heart disease and organic diseases. The40healthy subjects were comparable with pure2-DM patients in terms of sex and age. Patients with hypertension were excluded in pure2-DM group, and exclusive criteria included:①presence of history of heart diseases;②other metabolic disease except2-DM,connective tissue disease;③presence of diabetic complications(retinal disease, periphery vascular disease), presence of severe dysfunction of liver and kidney;④pregnant woman in perinatal period;⑤abnormal electrocardiography;⑥EF<55%and FS<25%when undergoing routine echocardiography.Subjects were in echocardiography and measurement of fasting plasma glucose and glycosylated hemoglobin A1c in all patients with type2diabetes before and after treatment3months,6months,9months. Two-dimensional images of apical four, two chambers and apical long-axis view were obtained with S2000ultrasound system. The longitudinal left ventricular regional systolic myocardial function was analyzed with VVI software. Parameters included myocardial velocity (Vmax), strain (Smax), strain rate (SRmax) in16segments of6ventricular walls.Results:Myocardial systolic Vmax gradually decreased from basal to apical segment with statistically significance in the control group (P<0.01), whereas no differences were found about Smax and SRmax among basal, middle and apical segment (P>0.05).The changes trends of Vmax, Smax and SRmax were identical in2-DM and2-DM&HP group. The longitudinal systolic myocardial Vmax, Smax, and SRmax in each segment were significantly lower in pure2-DM and2-DM&HP group than in the control group (P＜0.01), and with much lower in2-DM&HP group compared with pure2-DM group (P<0.05). After treatment (strictly controlling of blood glucose for nine months, HbAlc<7%) the longitudinal systolic myocardial Vmax, Smax, and SRmax in each segment in2-DM were significantly improved than before treatment(P<0.05), although it was still lower than in the control group (P<0.05);though the VVI parameters in2-DM&HP patients increased,the diversity had no obvious difference statistical significance.Conclusions:Systolic longitudinal parameters of left ventricule changed prior to presence of clinical symptoms in2-DM patients, which indicated that2-DM patients had subclinical left ventricular systolic dysfunction. All the VVI parameters in DM&HP group were lower than in2-DM group, which indicated that hypertension could worsen myocardial impairment. After treatment (strictly controlling of blood glucose for nine months,HbA1c<7%) all the parameters in2-DM group has been improved, which indicated that timely treatment could improve the left ventricular systolic function in pure2-DM patients. VVI could objectively and sensitively detect subclinical left ventricular systolic dysfunction and the changes after treatment in patients with2-DM and therefore could be a useful tool in assessing the myocardial regional systolic function.