title: Cardiac output calculation and three-dimensional echocardiography.
abstract: OBJECTIVE
  To compare the determination of stroke volume (SV) and cardiac output (CO) using 2-dimensional (2D) versus 3-dimensional (3D) transesophageal echocardiography (TEE).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Tertiary care university hospital.
  
  
  METHODS
  35 patients without structural valve abnormalities undergoing isolated coronary artery bypass grafting.
  
  
  METHODS
  Left ventricular outflow tract (LVOT) diameter determined with 2D TEE was used to estimate LVOT cross-sectional area (CSALVOT). LVOT area was measured directly with 3D TEE by planimetry on an en face view. SV and CO were calculated for both methods using the continuity equation.
  
  
  RESULTS
  The area of the LVOT differed significantly between methods, being significantly larger in the 3D method (3.57±0.70 cm(2)v 3.98±0.93 cm(2)) . This resulted in a 10% lower CO with the 2D method of LVOT area estimation.
  
  
  CONCLUSIONS
  LVOT area is underestimated with the single- axis 2D method when compared with 3D planimetered area. This results in a CO that is approximately 10% lower with the 2D method.
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Department of Anesthesia, Hospital México de la Caja Costarricense del Seguro Social, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Mario
authors.initials: M
authors.lastname: Montealegre-Gallegos
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA. Electronic address: fmahmood@bidmc.harvard.edu.
authors.forename: Feroze
authors.initials: F
authors.lastname: Mahmood
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Khurram
authors.initials: K
authors.lastname: Owais
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Phillip
authors.initials: P
authors.lastname: Hess
authors.affiliation: Department of Anesthesiology and Pain Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Jayant S
authors.initials: JS
authors.lastname: Jainandunsing
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Robina
authors.initials: R
authors.lastname: Matyal
mesh_terms: D000368:Aged; D019412:Anatomy, Cross-Sectional; D002302:Cardiac Output / Q000502:physiology*; D001026:Coronary Artery Bypass; D004452:Echocardiography; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D017548:Echocardiography, Transesophageal; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
keywords: cardiac output; left ventricular outflow tract, stroke volume, transesophageal echocardiography, 2D vs 3D