Blood velocity distributions within intact canine arterial bifurcations.
Am J Physiol
; 262(5 Pt 2): H1592-9, 1992 May.
Article
em En
| MEDLINE
| ID: mdl-1590464
ABSTRACT
As local variations in blood flow are implicated in atherogenesis at bifurcations, we measured in vivo blood velocities in different planes within exposed iliofemoral arterial bifurcations in 8 dogs using 20-MHz, 80-channel Doppler ultrasound velocimetry. Cardiac frequency was fixed at 2 Hz by pacing. Local geometry was characterized using 25-MHz, B-mode ultrasound images, photographs, and methacrylate casts. The bifurcations were asymmetrical and planar to within 5 degrees, the diameter ratios of the daughter vessels ranged from 1.47 to 2.00, and the angles between them ranged from 40 to 76 degrees. Measured velocities indicated that just upstream of the bifurcation mean peak Reynolds numbers ranged from 196 to 564 and Womersley (frequency) parameters ranged from 2.00 to 4.1. At the level of the bifurcation, secondary flows were insignificant in the normal plane but strong in the plane of the bifurcation. As a result, two-dimensional velocity fields, reconstructed by vector addition of velocities measured in the plane of the bifurcation, differed markedly from the one-dimensional profiles calculated assuming flow parallel to the vessel axis. In the two-dimensional velocity fields, forward flow was directed toward the flow divider and reversal occurred earliest near the outer wall. Wide spatial and temporal variations in the shear stress at the endothelium are implied by these detailed, in vivo measurements of the bifurcation velocity fields.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Velocidade do Fluxo Sanguíneo
/
Artéria Femoral
/
Artéria Ilíaca
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
Reino Unido