title: Validation of noninvasive measurements of cardiac output in mice using echocardiography.
abstract: BACKGROUND
  Although multiple echocardiographic methods exist to calculate cardiac output (CO), they have not been validated in mice using a reference method.
  
  
  METHODS
  Echocardiographic and flow probe measurements of CO were obtained in mice before and after albumin infusion and inferior vena cava occlusions. Echocardiography was also performed before and after endotoxin injection. Cardiac output was calculated using left ventricular volumes obtained from an M-mode or a two-dimensional view, left ventricular stroke volume calculated using the pulmonary flow, or estimated by the measurement of pulmonary velocity time integral (VTI).
  
  
  RESULTS
  Close correlations were demonstrated between flow probe-measured CO and all echocardiographic measurements of CO. All echocardiographic-derived CO overestimated the flow probe-measured CO. Two-dimensional image-derived CO was associated with the smallest overestimation of CO. Interobserver variability was lowest for pulmonary VTI-derived CO.
  
  
  CONCLUSIONS
  In mice, CO calculated from two-dimensional parasternal long-axis images is most accurate when compared with flow probe measurements; however, pulmonary VTI-derived CO is subject to less variability.
authors.affiliation: Ultrasound Cardiac Laboratory, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
authors.forename: François
authors.initials: F
authors.lastname: Tournoux
authors.forename: Bodil
authors.initials: B
authors.lastname: Petersen
authors.forename: Hélène
authors.initials: H
authors.lastname: Thibault
authors.forename: Lin
authors.initials: L
authors.lastname: Zou
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Raher
authors.forename: Baptiste
authors.initials: B
authors.lastname: Kurtz
authors.forename: Elkan F
authors.initials: EF
authors.lastname: Halpern
authors.forename: Miguel
authors.initials: M
authors.lastname: Chaput
authors.forename: Wei
authors.initials: W
authors.lastname: Chao
authors.forename: Michael H
authors.initials: MH
authors.lastname: Picard
authors.forename: Marielle
authors.initials: M
authors.lastname: Scherrer-Crosbie
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D000818:Animals; D002302:Cardiac Output; D004195:Disease Models, Animal; D004452:Echocardiography / Q000379:methods*; D004731:Endotoxins / Q000494:pharmacology; D006439:Hemodynamics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D004731:Endotoxins