title: Quantitative analysis of aortic regurgitation: real-time 3-dimensional and 2-dimensional color Doppler echocardiographic method--a clinical and a chronic animal study.
abstract: BACKGROUND
  For evaluating patients with aortic regurgitation (AR), regurgitant volumes, left ventricular (LV) stroke volumes (SV), and absolute LV volumes are valuable indices.
  
  
  OBJECTIVE
  The aim of this study was to validate the combination of real-time 3-dimensional echocardiography (3DE) and semiautomated digital color Doppler cardiac flow measurement (ACM) for quantifying absolute LV volumes, LVSV, and AR volumes using an animal model of chronic AR and to investigate its clinical applicability.
  
  
  METHODS
  In 8 sheep, a total of 26 hemodynamic states were obtained pharmacologically 20 weeks after the aortic valve noncoronary (n = 4) or right coronary (n = 4) leaflet was incised to produce AR. Reference standard LVSV and AR volume were determined using the electromagnetic flow method (EM). Simultaneous epicardial real-time 3DE studies were performed to obtain LV end-diastolic volumes (LVEDV), end-systolic volumes (LVESV), and LVSV by subtracting LVESV from LVEDV. Simultaneous ACM was performed to obtain LVSV and transmitral flows; AR volume was calculated by subtracting transmitral flow volume from LVSV. In a total of 19 patients with AR, real-time 3DE and ACM were used to obtain LVSVs and these were compared with each other.
  
  
  RESULTS
  A strong relationship was found between LVSV derived from EM and those from the real-time 3DE (r = 0.93, P <.001, mean difference (3D - EM) = -1.0 +/- 9.8 mL). A good relationship between LVSV and AR volumes derived from EM and those by ACM was found (r = 0.88, P <.001). A good relationship between LVSV derived from real-time 3DE and that from ACM was observed (r = 0.73, P <.01, mean difference = 2.5 +/- 7.9 mL). In patients, a good relationship between LVSV obtained by real-time 3DE and ACM was found (r = 0.90, P <.001, mean difference = 0.6 +/- 9.8 mL).
  
  
  CONCLUSIONS
  The combination of ACM and real-time 3DE for quantifying LV volumes, LVSV, and AR volumes was validated by the chronic animal study and was shown to be clinically applicable.
authors.affiliation: Department of Cardiology/F 15, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. shiotat@ccf.org
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiota
authors.forename: Michael
authors.initials: M
authors.lastname: Jones
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsujino
authors.forename: Jian Xin
authors.initials: JX
authors.lastname: Qin
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Zetts
authors.forename: Neil L
authors.initials: NL
authors.lastname: Greenberg
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Cardon
authors.forename: Julio A
authors.initials: JA
authors.lastname: Panza
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001810:Blood Volume / Q000502:physiology*; D004195:Disease Models, Animal; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D012756:Sheep; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*