title: Association of hypercholesterolemia and cardiac function evaluated by speckle tracking echocardiography in a rabbit model.
abstract: BACKGROUND
  Although hypercholesterolemia is a major risk factor for coronary artery disease (CAD), only limited data are available regarding its direct effect on myocardial function apart from CAD. The aim of this study was to evaluate LV systolic function using speckle-tracking echocardiography and investigate the relationship between hypercholesterolemia and myocardial function.
  
  
  METHODS
  Twenty-eight rabbits were randomly divided into three groups: 8 were fed normal chow for 3 months (group 1) and the remaining 20 were fed an atherogenic diet for 2 (group 2) or 3 months (group 3). Global systolic radial, circumferential and longitudinal peak strain were calculated. Serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and myocardial cholesterol levels were measured.
  
  
  RESULTS
  Global systolic longitudinal strain were both decreased in the group 2 and 3 (P < 0.001), whereas radial strain were increased (P < 0.001) compared with group 1. Global circumferential strain in the group 3 was significantly reduced (P < 0.001). Serum and myocardial cholesterol concentration markedly increased in the group 2 and group 3 (P < 0.001). There was a significant inverse correlation between longitudinal strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = - 0.723, r = - 0.794, r = - 0.700, P both < 0.001). A significant negative correlation was also noted between circumferential strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = - 0.518, P = 0.007; r = - 0.691, P < 0.001; r = - 0.659, P < 0.001). A significant positive correlation was found between radial strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = 0.432, P = 0.028; r = 0.602, P = 0.001; r = 0.469, P = 0.016).
  
  
  CONCLUSIONS
  Although LV morphology and ejection fractions were not different among the three groups, elevated concentration of cholesterol, especially in serum LDL-C, was significantly associated with LV systolic dysfunction. The findings also indicate that reductions in longitudinal was the first appeared, followed by circumferential, and was compensated for by increasing radial strain.
authors.forename: Liyun
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Echocardiography, Center of Medical Ultrasound, First Affiliated Hospital of Xinjiang Medical University, No, 137, Li Yu Shan South Road, Urumqi 830011, China. mym1234@126.com.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Mu
authors.forename: Wei
authors.initials: W
authors.lastname: Han
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000097:blood; D004452:Echocardiography / Q000379:methods; D006937:Hypercholesterolemia / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D011817:Rabbits; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000000981:diagnostic imaging* / Q000209:etiology
chemical_list: D002784:Cholesterol
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