Impairment of Right Ventricular Diastolic Function in Early Type 2 Diabetes

Background and Objectives：Diabetes is associated with a unique form of cardiomyopathy in the absence of atherosclerosis. The mechanisms of diabetic cardiomyopathy have not been defined, but is associated with early left ventricular (LV) diastolic dysfunction following an altered LV contractile performance. However, less attention has been paid to the right ventricular (RV) diastolic function in diabetes. Therefore, the changes in the RV ans LV filling dynamics, in patients with early type 2 diabetes, were investigated. Subjects and Methods：The transtricuspid and trans-mitral flows were assessed by transthoracic Doppler echocardiography, at maximal inspiration and expiration, in 48 subjects (mean age：62±9 years, M：F=16：32) with type 2 diabetes (Type 2 DM group) and 34 normal subjects (control group；mean age：59±9 years, M：F=15：19, ranging from 45-75 years of age) with normal LV systolic function and ECG at rest. Subjects with diabetic complication, nephropathy (Cr>1.5 mg/ dL), LVH and COPD were excluded. Results：The mitral E/A ratio and DT (deceleration time) showed no significant difference between the type 2 DM and control groups. The LV and RV systolic functions also showed no significant difference between the two groups. However, the type 2 DM group had a lower tricuspid E/A ratio (0.98±0.25 vs. 1.17±0.21, p<0.001) and a longer tricuspid DT (241±65 msec vs. 208±51 msec, p=0.016) than the control group. Conclusion：The right ventricular diastolic function is frequently abnormal in early type 2 diabetes. This suggests that right ventricular diastolic dysfunction may be an important predictor for the early detection