title: Aortic regurgitant flow by color Doppler measurement of the local velocity 7 mm above the leak orifice--Part 2: Comparison with cardiac catheterization.
abstract: OBJECTIVE
  An in vitro study of the flow convergence region in aortic regurgitation has shown that regurgitant flow rate can be derived from the local velocity V(7 mm) at 7 mm distance above the leak orifice. This clinical study was performed to test this method in patients.
  
  
  RESULTS
  In 67 patients with aortic regurgitation, the flow convergence region was imaged by color Doppler. By analogy with the afore mentioned in vitro study, velocity profiles of the acceleration across the flow convergence region were read from the color maps. The profiles were fitted by using a multiplicative regression model. The V(7 mm) was read from the regression curve, and instantaneous regurgitant flow Q was derived from the V(7 mm) with the equation developed in vitro (Q = V(7 mm).cm2/0.28). Q showed a close association with the angiographic grade. Q-derived regurgitant stroke volume correlated significantly with invasive measurements by the angio-Fick method (r = 0.897, SEE = 19.9 ml, y = 0.88x + 5.9 ml).
  
  
  CONCLUSIONS
  Within the color Doppler flow convergence region of aortic regurgitation, the local velocity at 7 mm distance to the leak reflects regurgitant flow rate.
authors.affiliation: Abt. Innere Medizin II, Medizinische Klinik und Poliklinik, Universität Ulm, Germany. martin.giesler@medizin.uni-ulm.de
authors.forename: M
authors.initials: M
authors.lastname: Giesler
authors.forename: D
authors.initials: D
authors.lastname: Bajtay
authors.forename: R A
authors.initials: RA
authors.lastname: Levine
authors.forename: M
authors.initials: M
authors.lastname: Stein
authors.forename: G
authors.initials: G
authors.lastname: Grossmann
authors.forename: M
authors.initials: M
authors.lastname: Kochs
authors.forename: M
authors.initials: M
authors.lastname: Höher
authors.forename: V
authors.initials: V
authors.lastname: Hombach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D002908:Chronic Disease; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008297:Male; D008875:Middle Aged