title: [Shearing anomalies of the arterial endothelium in essential arterial hypertension].
abstract: Brachial artery wall shear rate and stress were studied in 20 untreated hypertensive patients and 11 normotensive controls of similar age. A pulsed Doppler velocimeter enabled to determine the internal diameter, the mean cross-sectional blood velocity and the systolic centerline blood velocity of the brachial artery. A coaxial cylinder viscosimeter provided blood viscosity at a shear rate of 96 s-1. A Poiseuille model of arterial flow was used for evaluating wall shear rate from the ratio between blood velocity and arterial diameter and wall shear stress from the product between shear rate and blood viscosity. Shear rate and stress were expressed in terms of systolic and mean values by using respectively systolic centerline and mean cross-sectional blood velocities. Comparatively to normal controls, hypertensive patients had higher blood viscosity (4.80 +/- 0.08 vs 4.28 +/- 0.09 cpoise, p less than 0.001) lower systolic wall shear rate (303 +/- 18 vs 413 +/- 20 s-1, p less than 0.001), lower mean wall shear rate (70 +/- 6 vs 109 +/- 16 s-1, p less than 0.01) and lower systolic wall shear stress (13.86 +/- 0.81 vs 17.02 +/- 1.26, p less than 0.001) but mean wall shear stress was not statistically different between patients and controls. Such wall shear abnormalities are described for the first time in large artery of hypertensive patients and merit attention because of the experimental critical role of low shear conditions on the atherogenic process.
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001809:Blood Viscosity; D001916:Brachial Artery / Q000473:pathology / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000473:pathology / Q000503:physiopathology*; D014463:Ultrasonography
vernacular_title: Anomalies du cisaillement de l'endothélium artériel dans l'hypertension artérielle essentielle.