Objective To evaluate the characteristics of a rat model of heart failure with a preserved ejection fraction( HFpEF) induced by combined factors, and to investigate the correlation of myocardial strain parameters to myocardial hypertrophy and fibrosis. Methods Eight WKY rats and eight spontaneously hypertensive rats(SHR)served as control groups and were fed normal feed until the end of the experiment. Thirty-two SHR rats were equally divided into SHR + S, SHR + F, SHR + SF, and SHR + Combined groups, and fed high-salt, high-fat, high-salt-fat, or high-salt-fat-sugar feed, respectively, in combination with intraperitoneal injection of streptozotocin for 30 weeks. After modeling, the heart weight / body weight(HW/ BW)ratio, systolic blood pressure( SBP), and diastolic blood pressure(DBP) were measured. Echocardiography was performed to measure the left ventricular (LV)end-diastolic internal diameter(LVIDd), LV anterior wall thickness(LVAWd), LV posterior wall thickness (LVPWd), LV ejection fraction( LVEF), isovolumetric diastolic time(IVRT), and peak early diastolic passive filling velocity( E) / early diastolic mitral annular velocity( e’). Speckle tracking echocardiography was conducted to determine the global longitudinal strain(GLS) and strain rate(GLSr), global radial strain(GRS) and strain rate(GRSr), as well as the global circumferential strain(GCS) and strain rate (GCSr).Serum was collected and analyzed for triglycerides(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDLC), glucose(GLU), and glycated serum protein (GSP). ELISA were used to measure serum B-type brain natriuretic peptide(BNP), angiotensin Ⅱ(AngⅡ), and galectin-3(Gal-3). Myocardial tissue was subjected to HE and Masson staining for cardiomyocytes and myocardial fibrosis, and the cardiomyocyte cross-sectional area (CSA)and collagen volume fraction( CVF) were calculated. Additionally, the correlation of myocardial strain parameters to CSA and CVF was analyzed. Results Compared with the control group, in model groups, especially the SHR + combined group, HW/ BW,SBP, DBP, serum indexes(TC, TG, LDL-C, GLU, GSP, BNP, AngⅡ, and Gal-3) and echocardiographic parameters (LVIDd, LVAWd, LVPWd, IVRT, and E/ e’) were significantly up-regulated. Absolute values of speckle-tracking echocardiographic parameters (GLS, GLSr, GRS, GRSr, GCS, and GCSr)were decreased considerably. HE and Masson staining of myocardial tissues suggested marked cardiomyocyte hypertrophy and fibrosis, and significant increases were observed in CSA and CVF(P< 0. 05). Correlation analysis showed that GLSr, GCS, and GCSr were strongly linked to CSA, and GLS, GLSr, and GCSr were strongly linked to CVF(P< 0. 01). Conclusions A rat model of HFpEF induced by hypertension and dysregulation of glucolipid metabolism replicated the basic characteristics of HFpEF in terms of etiology, clinical features, and myocardial pathological changes, and might be a reliable animal model of metabolic syndrome-related HFpEF. Moreover, myocardial strain indices were closely related to myocardial hypertrophy and fibrosis and might indirectly reflect subtle myocardial lesions and dysfunction.