title: Speckle tracking echocardiography in patients with septic shock: a case control study (SPECKSS).
abstract: BACKGROUND
  Sepsis-induced myocardial dysfunction is a well-recognized condition and confers worse outcomes in septic patients. Echocardiographic assessment by conventional parameters such as left ventricular ejection fraction (LVEF) is often affected by ongoing changes in preload and afterload conditions. Novel echocardiographic technologies such as speckle tracking echocardiography (STE) have evolved for direct assessment of the myocardial function. We investigate the measurement of myocardial strain by speckle tracking echocardiography for the diagnosis of sepsis-induced myocardial dysfunction.
  
  
  METHODS
  This is a case-control study at a university-affiliated medical intensive care unit. Consecutive adult medical patients admitted with a diagnosis of septic shock were included. Patients with other causes of myocardial dysfunction were excluded. They were compared to age-matched, gender-matched, and cardiovascular risk-factor-matched controls, who were admitted to hospital for sepsis but did not develop septic shock. Transthoracic echocardiography was performed on all patients within 24 hours of diagnosis, and a reassessment echocardiogram was performed in the study group of patients upon recovery.
  
  
  RESULTS
  Patients with septic shock (n = 33) (study group) and 29 matched patients with sepsis but no septic shock (control group) were recruited. The mean sequential organ failure assessment (SOFA) score for the study and control groups were 10.2 and 1.6, respectively (P < 0.001). In patients with septic shock, the mean arterial pressure was lower (76 mmHg vs 82 mmHg, P = 0.032), and the heart rate was higher (99 bpm vs 86 bpm, P = 0.008). The cardiac output (5.9 L/min vs 5.5 L/min, P = 0.401) and systemic vascular resistance (1090 dynes•sec/cm(5) vs 1194 dynes•sec/cm(5), P = 0.303) were similar. The study group had a greater degree of myocardial dysfunction measured by global longitudinal strain (GLS) (-14.5 % vs -18.3 %, P <0.001), and the myocardial strain differed upon diagnosis and recovery (-14.5 % vs -16.0 %, P = 0.010). Conventional echocardiographic measurements such as LVEF (59 % in the study group vs 61 % in the control group, P = 0.169) did not differ between the two groups.
  
  
  CONCLUSIONS
  Speckle tracking echocardiography can detect significant left ventricular impairment in patients with septic shock, which was not otherwise detectable by conventional echocardiography. The reversible nature of myocardial dysfunction in sepsis was also demonstrable. This echocardiographic technique is useful in the diagnosis and monitoring of sepsis-induced myocardial dysfunction.
authors.affiliation: Department of Adult Intensive Care, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China. drpaulineyng@gmail.com.
authors.forename: Pauline Yeung
authors.initials: PY
authors.lastname: Ng
authors.affiliation: Department of Adult Intensive Care, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China.
authors.forename: Wai Ching
authors.initials: WC
authors.lastname: Sin
authors.affiliation: Cardiac Medical Unit, Grantham Hospital, 125 Wong Chuk Hang Road, Hong Kong, China.
authors.forename: Andrew Kei-Yan
authors.initials: AK
authors.lastname: Ng
authors.affiliation: Department of Adult Intensive Care, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China.
authors.forename: Wai Ming
authors.initials: WM
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D002302:Cardiac Output / Q000502:physiology; D016022:Case-Control Studies; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012772:Shock, Septic / Q000532:radiotherapy*
keywords: Global longitudinal strain; Sepsis; Sepsis-induced myocardial dysfunction; Septic cardiomyopathy; Septic shock; Speckle tracking echocardiography; Speckle tracking imaging; Strain