Evaluation of left ventricular systolic function in early simple obese rats with two-dimensional speckle tracking imaging / 中国医学影像技术

ABSTRACT

Objective To evaluate left ventricular systolic function with two-dimensional speckle tracking imaging (2D-STI) in rats with simple obesity.Methods A total of 16 healthy male rats were fed with normal diet (NF group,n=6)and rich fat diet (group HFD,n=10) for 12 weeks.The parameters of conventional echocardiography were recorded,and the strain and strain rate of left ventricular myocardium were analyzed with 2D-STI.The degree of myocardial fibrosis,mast cell infiltration and the expression level of light chain 3 (LC3) protein were observed.Results Compared with NF group,in HFD group,the weight,abdominal circumference,abdominal fat content,fasting blood glucose and triglyceride increased (all P＜0.05),while the radial strain rate of anterior septum,the radial strain of anterior septum and anterior wall in left ventricular decreased (all P＜0.05),so did the longitudinal strain and strain rate in posterior septal basal segment,middle segment,apical segment and lateral wall basal segments in left ventricle (all P＜0.01).In HFD group,the arrangement of cardiac muscle cells was disordered,and the fat vacuoles was found;the myocardial collagen fiber deposition and the infiltration of mast cells obviously increased,while the expression of LC3 protein decreased.Conclusion The left ventricular function of early stage obese rats has been damaged in varying degrees when no obvious changes of heart structure could be observed.