title: Two-dimensional color Doppler echocardiography for left ventricular stroke volume assessment: a comparison study with three-dimensional echocardiography.
abstract: OBJECTIVE
  Whether measurement of left ventricular outflow tract diameter (LVOTd) using color Doppler (CD) in order to more accurately define LVOTd is more accurate for determination of stroke volume (SV) than gray scale and compare it with direct measurement of LVOT area (a) using three-dimensional echocardiography (3DE) for SV determination.
  
  
  RESULTS
  Twenty-one volunteers were examined. LVOTa was calculated by two-dimensional echocardiography (2DE) using the following formula: π× (d/2)(2) , d = LVOT diameter by gray scale and CD, respectively. Planimetry of LVOTa was performed in parasternal long axis using 3DE. Eccentricity Index was calculated using the lateral and anterior-posterior LVOTd. SV was obtained by four different methods: (1) 2D gray scale, (2) 2D color, (3) LVOTa × LVOT velocity time integral, and (4) SV by Simpson's biplane method. Gray scale LVOTd was significantly smaller compared to LVOTd obtained with CD (P < 0.05). Significant differences occurred between LVOTa gray scale and CD (3.29 ± 0.74 cm(2) vs 3.67 ± 0.70 cm(2) , P < 0.05) and between LVOTa calculated by gray scale in comparison to 3DE planimetry; (3.29 ± 0.74 cm(2) vs 3.61 ± 0.89 cm(2) , P = 0.011). Half of the subjects had at least 17% difference between the lateral and anterior-posterior LVOTd. There were significant differences between SV by 2D gray scale and 2D CD (82.8 ± 17.1 mL vs 92.4 ± 16.8 mL, P < 0.05) and between 2D gray scale and 3DE planimetry (82.8 ± 17.1 mL vs 90.7 ± 19.8 mL, P = 0.025).
  
  
  CONCLUSIONS
  Our study demonstrates LVOT being frequently elliptical. SV and LVOTa were found to be similar when comparing 2DE CD and 3DE planimetry and showed higher values in comparison to 2DE gray scale, which suggests 2DE CD to be an alternative approach for SV assessment.
authors.affiliation: Department of Clinical Physiology            Department of Cardiology and Clinical Physiology            Department of Cardiology, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Cristina Da
authors.initials: CD
authors.lastname: Silva
authors.forename: Fátima
authors.initials: F
authors.lastname: Pedro
authors.forename: Lizandra
authors.initials: L
authors.lastname: Deister
authors.forename: Anders
authors.initials: A
authors.lastname: Sahlén
authors.forename: Aristomenis
authors.initials: A
authors.lastname: Manouras
authors.forename: Kambiz
authors.initials: K
authors.lastname: Shahgaldi
mesh_terms: D018618:Echocardiography, Doppler, Color / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult