Shear stress depends on vascular territory: comparison between common carotid and brachial artery.
Shear stress (SS) is thought to be constant throughout the vascular system. Evidence for this supposition is scarce, however. To verify this hypothesis in vivo, we assessed common carotid (CCA) and brachial artery (BA) peak and mean wall shear rate (SR) noninvasively in 10 healthy volunteers (23.7 +/- 3.4 yr) with an ultrasound SR estimation system. SS was estimated from SR and calculated whole blood viscosity. SR was higher (P < 0.05) in the CCA (mean: 359 +/- 111 s(-1); peak: 1,047 +/- 345 s(-1)) than in the BA (mean: 95 +/- 24 s(-1); peak: 770 +/- 170 s(-1)). Whole blood viscosity was higher in the BA than in the CCA (5.1 +/- 0.7 vs. 3.3 +/- 0.6 mPa. s; P < 0.001). Peak SS did not differ between the CCA and the BA, whereas mean SS was significantly higher in the CCA (1.15 +/- 0.21 Pa) than in the BA (0.48 +/- 0.15 Pa; P < 0.001). These results demonstrate that BA SS strongly deviates from CCA SS in vivo.
Dammers
Ruben
R
Department of Surgery, University Hospital Maastricht, The Netherlands. r.dammers@bf.unimaas.nl
Stifft
Frank
F
Tordoir
Jan H M
JH
Hameleers
Jeroen M M
JM
Hoeks
Arnold P G
AP
Kitslaar
Peter J E H M
PJ
D000328:Adult; D001809:Blood Viscosity; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013314:Stress, Mechanical; D014463:Ultrasonography