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Protodiastolic blood flow-factor for intimal damage
of large arteries in atherosclerosis development.

F. Todua, M. Beraia
Institute of radiology and interventional diagnostics. Tbilisi. Georgia

Purpose: It is now accepted that hemodynamic forces are localizing factors in pathogenesis, and the places characterized by low and oscillatory levels of wall share stress are preferentially sites for endothelial damage. Some of these alterations are not well understood. The aim of the study was to calculate blood flow features of the aortic arch for revealing flow patterns at the sites of vascular branching.

Methods: 15 healthy persons were investigated on 1.5MR imager Siemens-Sonata Cardio-PC.MRA.fl2D,TR-47ms,TE-2.7ms.FoV.292.360.SL6.The patients’ age was within 25-37.

Results: Places with systolic low peak velocity and low share stress acquire a high wall tensile stress. At the time of protodiastola, the blood flow at these places becomes retrograde. Tangential forces to the endothelium are correlated with blood acceleration, reached 32,3-43.0N/m2, and can damage endothelial sheet.

Conclusion: Protodiastolic share stress at the places of vascular branching is the main factor for the endothelial damage for atherosclerosis.

Literature:

1. Stary HC, Chandler AB, Dinsmore RE, Fuster V, Glagov S, Insull W, Rosenfeld ME , Schaffer SA, Schwartz CJ, Wagner WD, Wissler RW. A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis. A report from the Committee on vascular lesions of the Council on Arteriosclerosis, American Heart Association. Arterioscler Thromb Vasc Biol 1995; 15: 1512-1531

2. Hayden MR, Tyagi SC. Arterial vascular remodeling: the endothelial cell's central role. Mo Med 1998; 95: 213-217

3. Ku DN, Giddens DP, Zarins CK, Glagov S. Pulsatile flow and atherosclerosis in the human carotid bifurcation. Positive correlation between plaque location and low and oscillating shear stress. Arteriosclerosis 1985; 5: 293-302

4. Zarins CK, Zatina MA, Giddens DP, Ku DN, Glagov S. Shear stress regulation of artery lumen diameter in experimental atherogenesis. J Vasc Surg 1987; 5:413-420

5. Caro CG, Doorly DJ, Tarnawski M, Scott KT, Long Q, Dumoulin CL. Non planar curvature and branching of arteries and non-planar-type flow. Proc R Soc Lond A 1996; 452:185-197

6. Liu H, Iwase H, Himeno R.Global computational modeling of cardiovascular blood flow- Analysis of biofluid dynabics in left ventricle and aorta. BED-vol.50, 2001. Bioengineering Conference ASME 2001.

7. Beraia M.V, Todua F.A. Blood flow to aorta and its relationship with aortic branches. Europian Radiology.2002;12.11:117-118.

             8. Fung Y.C. “ Biomechanics, Circulation”, Second Edition, Springer-Verlag-, New York, 1997.

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