title: Real-time three-dimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload.
abstract: BACKGROUND
  The lack of a suitable noninvasive method for assessing right ventricular (RV) volume and function has been a major deficiency of two-dimensional (2D) echocardiography. The aim of our animal study was to test a new real-time three-dimensional (3D) echo imaging system for evaluating RV stroke volumes.
  
  
  RESULTS
  Three to 6 months before hemodynamic and 3D ultrasonic study, the pulmonary valve was excised from 6 sheep (31 to 59 kg) to induce RV volume overload. At the subsequent session, a total of 14 different steady-state hemodynamic conditions were studied. Electromagnetic (EM) flow probes were used for obtaining aortic and pulmonic flows. A unique phased-array volumetric 3D imaging system developed at the Duke University Center for Emerging Cardiovascular Technology was used for ultrasonic imaging. Real-time volumetric images of the RV were digitally stored, and RV stroke volumes were determined by use of parallel slices of the 3D RV data set and subtraction of end-systolic cavity volumes from end-diastolic cavity volumes. Multiple regression analyses showed a good correlation and agreement between the EM-obtained RV stroke volumes (range, 16 to 42 mL/beat) and those obtained by the new real-time 3D method (r=0.80; mean difference, -2.7+/-6.4 mL/beat).
  
  
  CONCLUSIONS
  The real-time 3D system provided good estimation of strictly quantified reference RV stroke volumes, suggesting an important application of this new 3D method.
authors.affiliation: Oregon Health Sciences University, Portland 97201-3098, USA.
authors.forename: T
authors.initials: T
authors.lastname: Shiota
authors.forename: M
authors.initials: M
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Chikada
authors.forename: C E
authors.initials: CE
authors.lastname: Fleishman
authors.forename: J B
authors.initials: JB
authors.lastname: Castellucci
authors.forename: B
authors.initials: B
authors.lastname: Cotter
authors.forename: A N
authors.initials: AN
authors.lastname: DeMaria
authors.forename: O T
authors.initials: OT
authors.lastname: von Ramm
authors.forename: J
authors.initials: J
authors.lastname: Kisslo
authors.forename: T
authors.initials: T
authors.lastname: Ryan
authors.forename: D J
authors.initials: DJ
authors.lastname: Sahn
mesh_terms: D000818:Animals; D019560:Echocardiography, Three-Dimensional; D004574:Electromagnetic Fields; D006439:Hemodynamics; D006801:Humans; D015588:Observer Variation; D012044:Regression Analysis; D015203:Reproducibility of Results; D012756:Sheep; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016278:Ventricular Function, Right