title: Two-dimensional speckle tracking imaging detects impaired myocardial performance in children with septic shock, not recognized by conventional echocardiography.
abstract: OBJECTIVE
  Sepsis is common in children and often results in cardiac dysfunction. Assessment of patients with sepsis-associated myocardial depression using ejection fraction and fractional shortening with conventional echocardiography is load dependent and often reveals cardiac dysfunction only after clinical deterioration has occurred. Speckle tracking imaging is a novel technology that can assess deformation and strain by tracking displacement of acoustic markers in the myocardium. We hypothesize that speckle tracking imaging will detect cardiac impairments during sepsis that are not appreciated by conventional echocardiography.
  
  
  METHODS
  Retrospective, observational study.
  
  
  METHODS
  A large, tertiary-care pediatric intensive care unit.
  
  
  METHODS
  Fifteen pediatric patients with septic shock, and 30 age- and gender-matched healthy controls.
  
  
  METHODS
  Transthoracic echocardiograms from subjects with septic shock (by American College of Chest Physicians/Society of Critical Care Medicine consensus criteria) and controls were evaluated. Speckle tracking imaging was used to obtain tissue displacement, velocity, strain, and strain rate in radial, longitudinal, and circumferential planes. Ejection fraction and fractional shortening were determined by conventional methods. Comparisons between groups were made using a paired t test.
  
  
  RESULTS
  Compared to control subjects, children with septic shock demonstrated impaired myocardial performance as quantified by speckle tracking imaging. Significant differences were seen in circumferential and longitudinal strain (p < .001), strain rate (p < .05), radial displacement (p < .001), and rotational velocity and displacement (p < .01). There was no significant difference in ejection fraction and fractional shortening between septic patients and controls.
  
  
  CONCLUSIONS
  Speckle tracking imaging detected a number of significantly impaired measures of ventricular performance in children with sepsis, not appreciated by conventional echocardiography. This technology may improve our understanding and identification of myocardial depression in the critically ill septic child.
authors.affiliation: Department of Pediatric Critical Care Medicine, Children's National Medical Center, George Washington University School of Medicine, Washington, DC, USA. sbasu@cnmc.org
authors.forename: Sonali
authors.initials: S
authors.lastname: Basu
authors.forename: Lowell H
authors.initials: LH
authors.lastname: Frank
authors.forename: Kimberly E
authors.initials: KE
authors.lastname: Fenton
authors.forename: Craig A
authors.initials: CA
authors.lastname: Sable
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Levy
authors.forename: John T
authors.initials: JT
authors.lastname: Berger
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D015999:Multivariate Analysis; D012044:Regression Analysis; D012189:Retrospective Studies; D012772:Shock, Septic / Q000150:complications*; D016037:Single-Blind Method; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology