Evaluation Of Subclinical Left Ventricular Dysfunction With Velocity Vector Imaging In Patients With Latent Autoimmune Diabetes In Adults (LADA)

Backgroud: Diabetes mellitus (DM) is a chronic metabolic syndrome characterized by long-term persistent hyperglycemia. Recently, morbidity and mortality of DM are increasing progressively all over the world, and average onset age is gradually decreasing. Diabetic myocardiopathy is a common complication of DM and can lead to congestive heart failure. Thus, it is clinically important to evaluate cardiac function at early stage in patients with DM. Isomaa et al reported that morbidity of major vascular complication in latent autoimmune diabetes in adults (LADA) is higher than those in classic type 1 DM with same courses of disease, similar with type 2 DM. The relationship between blood sugar level and morbidity of coronary artery disease in LADA is closer than in type 2 DM. Studies indicated that cardiac systolic and diastolic function changed prior to presence of clinical symptoms in type 2 DM. Whereas few studies about cardiac longitudial globle and regional function in LADA have been reported so long.Objectives: To assess subclinical left ventricular systolic and diastolic function in normotensive LADA patients with normal ejection fraction and fractional shortening using velocity vector imaging (VVI), and observe the cardiac function changes compared with healthy subjects. Evaluate clinical uses of VVI to detect subclinical left ventricular systolic and diastolic function in LADA patients. Subjects and methods: LADA group: 60 LADA patients who visited Endocrine Research Institute in our hospital from 2005-2007. All the patients were diagnosed LADA and underwent observation and treatment. Among those patients, 32 were male and 28 female, between 32-75 years old, average age (51.833±12.073); All of the enrolled patients had history of disease more than 3 years, and fasting blood sugar (FBS) level were 4.34-21.98mmol/L. Exclusive criteria included:①had history of heart disease and hypertension;②presence of thyroid disease;③diabetic renal disease;④diabetic disease;⑤diabetic feet;⑥periphery vascular disease;⑦presence of myocardial ischemic symptom;⑧abnormal echocardiogram (ECG);⑨abnormal echocardiography in routine tests; EF<55%.Control group: 60 healthy subjects matched with LADA patients in terms of sexy and age. 32 were male and 28 female, between 32-75 years age, average age (51.467±12.170) . All of the subjects had no history of cardiovascular diseases or other organic diseases, with normal ECG, echocardiography, X-ray and biochemical tests. Digital dynamic imagings were collected and myocardial longitudinal velocity (SVmax), strain(Smax), strain rate (SRmax) and time to peak velocity, strain and strain rate of 16 segments were analyzed. Each parameter were measured 3 times and average values were obtained.Results: Myocardial longitudinal peek velocity in both systolic and diastolic period tended to decrease from basal, middle and apical segment in control group, whereas strain and strain rate had no significant differences. The same change tendency was observed in LADA group, but all the measured parameters were lower than those in control group with statistically differences (p<0.01). Myocardial velocity and strain in systolic and diastolic period, myocardial strain in systolic and early diastolic period in LADA group were significantly lower in comparison with control group (P <0.01) . Myocardial strain in late diastolic period had no differences between two groups. Time to peak velocity, strain and strain rate were longer in LADA group, but with no statistically significance (P >0.05) .Conclusion: Cardiac abnormal longitudinal systolic and diastolic function exists in subclinical LADA patients. VVI is a novel and noninvasive tool to quantitatively and objectively assess left ventricular regional systolic and diastolic function in the LADA patients; it can make trustworthy early diagnose of abnormal left ventricle myocardial performance in patients with subclinical LADA. It is prospective that VVI will be widely used with progressive development and more attention to early detect diabetic myocardiopathy.