title: The role of speckle tracking echocardiography in assessment of lipopolysaccharide-induced myocardial dysfunction in mice.
abstract: BACKGROUND
  Sepsis-induced myocardial dysfunction is a common and severe complication of septic shock. Conventional echocardiography often fails to reveal myocardial depression in severe sepsis due to hemodynamic changes; in contrast, decline of strain measurements by speckle tracking echocardiography (STE) may indicate impaired cardiac function. This study investigates the role of STE in detecting lipopolysaccharide (LPS)-induced cardiac dysfunction with mouse models.
  
  
  METHODS
  We evaluated cardiac function in 20 mice at baseline, 6 h (n=10) and 20 h (n=10) after LPS injection to monitor the development of heart failure induced by severe sepsis using 2-D and M-mode echocardiography. Ejection fraction (EF) and fractional shortening (FS) were measured with standard M-mode tracings, whereas circumferential and radial strain was derived from STE. Serum biochemical and cardiac histopathological examinations were performed to determine sepsis-induced myocardial injury.
  
  
  RESULTS
  Left ventricular (LV) myocardial function was significantly reduced at 6 h after LPS treatment assessed by circumferential strain (-14.65%±3.00% to -8.48%±1.72%, P=0.006), whereas there were no significant differences between 6 and 20 h group. Conversely, EF and FS were significantly increased at 20 h when comparing to 6 h (P<0.05) accompanied with marked decreases in EF and FS 6 h following LPS administration. Consistent with strain echocardiographic results, we showed that LPS injection leaded to elevated serum level of cardiac Troponin-T (cTnT), CK-MB and rising leucocytes infiltration into myocardium within 20 h.
  
  
  CONCLUSIONS
  Altogether, these results demonstrate that, circumferential strain by STE is a specific and reliable value for evaluating LPS-induced cardiac dysfunction in mice.
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Chu
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Yao
authors.initials: Y
authors.lastname: Gao
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Yanjuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Bingruo
authors.initials: B
authors.lastname: Wu
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Yao
authors.affiliation: 1 Department of Geriatrics, 2 Department of Cardiology, First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China ; 3 Departments of Genetics, Pediatrics and Medicine (Cardiology), Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA.
authors.forename: Di
authors.initials: D
authors.lastname: Xu
keywords: Sepsis; endotoxin-induced cardiac dysfunction; septic cardiomyopathy; speckle tracking echocardiography (STE); strain imaging