title: Speckle-tracking imaging to monitor myocardial function after coronary artery bypass graft surgery.
abstract: OBJECTIVE
  The purpose of this study was to investigate the changes in myocardial function in patients after coronary artery bypass graft (CABG) surgery using longitudinal and circumferential strain on speckle-tracking imaging.
  
  
  METHODS
  A total of 145 patients who successfully underwent CABG surgery with a left ventricular ejection fraction (LVEF) of 50% or greater were enrolled in this study. Patients were classified into 4 groups based on age: group 1 (33-59 years), group 2 (60-64 years), group 3 (65-69 years), and group 4 (70-79 years). Routine echocardiography and longitudinal and circumferential strain measurements on speckle-tracking imaging were performed 1 week before and 1, 3, and 6 months after the CABG.
  
  
  RESULTS
  In all groups, longitudinal strain increased significantly at 3 and 6 months after CABG therapy compared to baseline (P < .05). A significant increase in circumferential strain was found 1 month after the CABG in groups 1, 2, and 3, and a continuous increase in the parameter was observed in all groups 3 months after therapy (P < .05). However, the LVEF, left ventricular end-diastolic dimension, and stroke volume measured by routine echocardiography were not significantly changed after successful CABG treatment in all groups during 6 months of follow-up.
  
  
  CONCLUSIONS
  Based on the results of our study in all age groups, speckle-tracking imaging parameters are more effective than the LVEF, left ventricular end-diastolic dimension, and stroke volume for monitoring improvement in myocardial function after CABG surgery.
authors.affiliation: Department of Radiology, Fourth Hospital of Harbin Medical University, 37 Yiyuan St, 150001 Harbin, Heilongjiang, China. shenbzh@hotmail.com.
authors.forename: Zhe-Yu
authors.initials: ZY
authors.lastname: Yin
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Li
authors.forename: Ying-Feng
authors.initials: YF
authors.lastname: Tu
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Dong
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Zhao
authors.forename: Baozhong
authors.initials: B
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D002681:China / Q000453:epidemiology; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery*; D004452:Echocardiography / Q000706:statistics & numerical data*; D054459:Elasticity Imaging Techniques / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery*
keywords: coronary artery bypass graft; coronary heart disease; echocardiography; speckle-tracking imaging