title: [Evaluation of myocardial systolic function of heart failure induced by myocardial infarction in rats with strain and strain rate imagine].
abstract: OBJECTIVE
  To quantitatively detect variation in regional myocardial systolic function in heart failure rat model induced by myocardial infarction by strain and strain rate imaging.
  
  
  METHODS
  Seventy 2-month-old adult male SD rats were randomly assigned to 4 groups: a 4-week and a 8-week group after the operation (each n = 25) had thoracotomy, the pericardium opened and the anterior descending branch of left coronary artery ligated; a sham operation group (n = 10) had thoracotomy and the arcula cordis opened, but did not ligate the artery; a control group (n = 10) had no treatment. The changes of general state of health of the rats were observed and recorded every day. To assess the change of heart function, echocardiography was used at the end of the 4th week and 8th week after the surgery. To evaluate the change of heart function in heart failure rats, we quantitatively analyzed the regional myocardial systolic function in all rats by strain and strain rate imaging and myocardium to detect the level of MMP-9 at the end of the 4th week and 8th week. The repeatability and discrepancies of the results were all analyzed.
  
  
  RESULTS
  Obviously objective signs of heart failure manifested themselves in the survived mice 10 to 14 days after the surgery. Compared with the control group and the sham operation group, the fraction shortening (FS) and ejection fraction (EF) of the 4-week group after the operation were lower (P < 0.05), the left ventricle index (LV index) of the 8-week group after the operation was higher, left ventricle posterior wall index (LVPW index), interventricular septum index (IVS index), FS, and EF of the 8-week group after the operation were lower (P < 0.05), EF and FS of the 8-week group after the operation were lower than those of the 4-week group. Except the mid-inferior wall and base-inferior wall, the systolic peak strain, systolic peak strain rate, the strain of end-systole in all segments of the operation group were lower than those of the other 2 groups (P < 0.05). The post-systolic strain index of the operation group was higher than that of the other 2 groups (P < 0.05).
  
  
  CONCLUSIONS
  Strain and strain rate imaging of echocardiography can quantitatively evaluate the changing of regional myocardial systolic function in the heart failure rat model induced by myocardial infarction, with good repeatability.
authors.affiliation: Department of Ultrasound, Third Xiangya Hospital, Central South University, Changsha 410013, China. zhu0423@xy3yy.com
authors.forename: Wenhui
authors.initials: W
authors.lastname: Zhu
authors.forename: Shuijuan
authors.initials: S
authors.lastname: Tang
authors.forename: Xingxing
authors.initials: X
authors.lastname: Duan
mesh_terms: D000818:Animals; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D008297:Male; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013599:Systole; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*