Diastolic function of the right ventricle is impaired in experimental type 2 diabetic rat models

Authors: YA MIAO, WEI ZHANG, YUAN ZHONG, MING ZHONG, XIAO MA

Abstract: To evaluate diastolic function alterations of the right ventricle (RV) by echocardiography in type 2 diabetic rat models. Materials and methods: Male Wistar rats were divided into 2 groups: a control group (n = 8) and a diabetic group (n = 16, with 11 remaining at the end of the experiment), which was fed a high-fat and high-calorie diet and injected with streptozotocin (STZ). RV diastolic functional alteration of rat models was studied by the tricuspid flow Doppler (Ep, Ap, and Ep/Ap) and tissue Doppler imaging (TDI) (Em, Am, and Em/Am) of the lateral tricuspid annulus. RV structural alteration of rat models was studied by standard 2D and M-mode echocardiography. Results: Compared with the control group rats, at the 12th week after STZ injection, the rats of the diabetic group developed RV diastolic dysfunction, lower Em, and lower ratios (Ep/Ap, Em/Am). At the end of the experiment, at the 16th week after STZ injection, the rats of the diabetic group showed further decreased Ep, Em, and ratios (Ep/Ap, Em/Am) and significantly higher RV diameters compared with the control group rats. Conclusion: We demonstrated that the diastolic dysfunction of the RV was the earliest complication observed in type 2 diabetic rat models, using TDI and tricuspid flow Doppler. TDI showed a high sensitivity in detecting changes of RV diastolic function.

Keywords: Right ventricle, diastolic function, diabetic cardiomyopathy, echocardiography, rats

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