title: Calculation of aortic regurgitant volume by a new digital Doppler color flow mapping method: an animal study with quantified chronic aortic regurgitation.
abstract: OBJECTIVE
  The aim of the present study was to quantitate aortic regurgitant volume and regurgitant fraction in a chronic animal model with surgically created aortic regurgitation using a new semiautomated color Doppler flow calculation method.
  
  
  BACKGROUND
  The conventional noninvasive methods for evaluating the severity of aortic regurgitation have not been accepted widely nor compared with truly quantitative reference standards.
  
  
  METHODS
  Eight to 20 weeks after aortic regurgitation was surgically induced in six sheep, a total of 22 hemodynamic states were studied. Electromagnetic flow probes and meters provided reference flow data. Epicardial color Doppler echocardiographic studies were performed to image left ventricular outflow tract forward and aortic regurgitant blood flows. The new method digitally integrated spatial and temporal color flow velocity data for left ventricular outflow tract forward flow and ascending aortic regurgitant flow. The pulsed Doppler method using the velocity-time integral was also used to obtain regurgitant volumes and regurgitant fractions.
  
  
  RESULTS
  Regurgitant volumes and regurgitant fractions by the new method agreed well with those obtained electromagnetically, whereas the pulsed Doppler method overestimated these reference data (mean [+/-SD] difference 0.23 +/- 2.9 ml vs. 11 +/- 5.8 ml, p < 0.0001 for regurgitant volume; mean difference 1.2 +/- 7.6% vs. 19 +/- 13%, p < 0.0001 for regurgitant fraction).
  
  
  CONCLUSIONS
  This animal study, using strictly quantified aortic regurgitant volumes, demonstrated that the digital color Doppler method provides accurate aortic regurgitant volumes and regurgitant fractions without cumbersome measurements.
authors.affiliation: Oregon Health Sciences University, Portland, Oregon, USA.
authors.forename: T
authors.initials: T
authors.lastname: Shiota
authors.forename: M
authors.initials: M
authors.lastname: Jones
authors.forename: S
authors.initials: S
authors.lastname: Aida
authors.forename: H
authors.initials: H
authors.lastname: Tsujino
authors.forename: I
authors.initials: I
authors.lastname: Yamada
authors.forename: A
authors.initials: A
authors.lastname: Delabays
authors.forename: N G
authors.initials: NG
authors.lastname: Pandian
authors.forename: D J
authors.initials: DJ
authors.lastname: Sahn
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001783:Blood Flow Velocity; D002302:Cardiac Output; D002908:Chronic Disease; D018618:Echocardiography, Doppler, Color / Q000295:instrumentation / Q000379:methods*; D018619:Echocardiography, Doppler, Pulsed; D008432:Mathematical Computing; D012756:Sheep; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume