title: Computational study of pulsatile blood flow in prototype vessel geometries of coronary segments.
abstract: The spatial and temporal distributions of wall shear stress (WSS) in prototype vessel geometries of coronary segments are investigated via numerical simulation, and the potential association with vascular disease and specifically atherosclerosis and plaque rupture is discussed. In particular, simulation results of WSS spatio-temporal distributions are presented for pulsatile, non-Newtonian blood flow conditions for: (a) curved pipes with different curvatures, and (b) bifurcating pipes with different branching angles and flow division. The effects of non-Newtonian flow on WSS (compared to Newtonian flow) are found to be small at Reynolds numbers representative of blood flow in coronary arteries. Specific preferential sites of average low WSS (and likely atherogenesis) were found at the outer regions of the bifurcating branches just after the bifurcation, and at the outer-entry and inner-exit flow regions of the curved vessel segment. The drop in WSS was more dramatic at the bifurcating vessel sites (less than 5% of the pre-bifurcation value). These sites were also near rapid gradients of WSS changes in space and time - a fact that increases the risk of rupture of plaque likely to develop at these sites. The time variation of the WSS spatial distributions was very rapid around the start and end of the systolic phase of the cardiac cycle, when strong fluctuations of intravascular pressure were also observed. These rapid and strong changes of WSS and pressure coincide temporally with the greatest flexion and mechanical stresses induced in the vessel wall by myocardial motion (ventricular contraction). The combination of these factors may increase the risk of plaque rupture and thrombus formation at these sites.
authors.affiliation: Department of Naval Architecture and Marine Engineering, National Technical University of Athens, P.O. Box 64033, Zografos 15710, Athens, Greece. chaniotis@naval.ntua.gr <chaniotis@naval.ntua.gr>
authors.forename: A K
authors.initials: AK
authors.lastname: Chaniotis
authors.forename: L
authors.initials: L
authors.lastname: Kaiktsis
authors.forename: D
authors.initials: D
authors.lastname: Katritsis
authors.forename: E
authors.initials: E
authors.lastname: Efstathopoulos
authors.forename: I
authors.initials: I
authors.lastname: Pantos
authors.forename: V
authors.initials: V
authors.lastname: Marmarellis
mesh_terms: D000465:Algorithms; D001794:Blood Pressure / Q000502:physiology; D003198:Computer Simulation; D003323:Coronary Aneurysm / Q000473:pathology / Q000503:physiopathology; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology; D003328:Coronary Thrombosis / Q000473:pathology / Q000503:physiopathology; D003331:Coronary Vessels / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology; D010507:Periodicity; D010974:Platelet Aggregation / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D013314:Stress, Mechanical; D013997:Time Factors; D016276:Ventricular Function / Q000502:physiology
references.citation: Magn Reson Med. 1996 Apr;35(4):577-84
references.pmid: 8992209
references.citation: Med Eng Phys. 2008 Jan;30(1):9-19
references.pmid: 17412633
references.citation: Eur J Vasc Endovasc Surg. 1999 Oct;18(4):328-33
references.pmid: 10550268
references.citation: Hypertension. 1996 Mar;27(3 Pt 2):799-803
references.pmid: 8613243
references.citation: J Biomech. 2006;39(6):1116-28
references.pmid: 16549100
references.citation: J Biomech. 2004 May;37(5):709-20
references.pmid: 15047000
references.citation: Ann N Y Acad Sci. 2000 May;902:230-9; discussion 239-40
references.pmid: 10865843
references.citation: Circ Res. 1990 Apr;66(4):1045-66
references.pmid: 2317887
references.citation: Ann Biomed Eng. 2003 Apr;31(4):420-9
references.pmid: 12723683
references.citation: Comput Biomed Res. 1997 Feb;30(1):61-82
references.pmid: 9134307
references.citation: Prog Biophys Mol Biol. 2003 Apr;81(3):177-99
references.pmid: 12732261
references.citation: Circulation. 2006 Jun 13;113(23):2744-53
references.pmid: 16754802
references.citation: J Am Coll Cardiol. 1994 Mar 15;23(4):879-84
references.pmid: 8106692
references.citation: J Am Coll Cardiol. 1994 May;23(6):1289-95
references.pmid: 8176085
references.citation: Pathophysiol Haemost Thromb. 2005;34(6):255-62
references.pmid: 16772736
references.citation: Arterioscler Thromb Vasc Biol. 2006 Mar;26(3):663-9
references.pmid: 16385083
references.citation: AJR Am J Roentgenol. 2000 Jun;174(6):1657-65
references.pmid: 10845502
references.citation: Circulation. 2003 Jul 29;108(4):438-44
references.pmid: 12860915
references.citation: Stroke. 2002 Oct;33(10):2446-50
references.pmid: 12364736
references.citation: Proc R Soc Lond B Biol Sci. 1971 Feb 16;177(1046):109-59
references.pmid: 4396262
references.citation: Circulation. 1995 May 1;91(9):2488-96
references.pmid: 7729036
references.citation: Ann Biomed Eng. 2002 Apr;30(4):524-36
references.pmid: 12086003
references.citation: J Biomech. 1982;15(5):349-62
references.pmid: 7118950
references.citation: Arterioscler Thromb Vasc Biol. 1997 Oct;17(10):2061-5
references.pmid: 9351372
references.citation: J Biomech. 2002 Oct;35(10):1347-56
references.pmid: 12231280
references.citation: J Biomech Eng. 1996 Feb;118(1):74-82
references.pmid: 8833077
references.citation: Biorheology. 1994 Sep-Oct;31(5):565-86
references.pmid: 7833458
references.citation: Ann Biomed Eng. 1998 Nov-Dec;26(6):944-54
references.pmid: 9846933
references.citation: Bull Math Biol. 1984;46(1):127-37
references.pmid: 6713148
references.citation: J Biomech. 2006;39(4):742-9
references.pmid: 16439244
references.citation: Cardiovasc Res. 1980 Oct;14(10):568-76
references.pmid: 7214391
references.citation: J Biomech. 2006;39(2):339-47
references.pmid: 16321636
references.citation: Cardiovasc Res. 1989 Sep;23(9):741-7
references.pmid: 2611812
references.citation: Histochem Cell Biol. 2004 Oct;122(4):353-67
references.pmid: 15338226
references.citation: Arteriosclerosis. 1985 May-Jun;5(3):293-302
references.pmid: 3994585
references.citation: Curr Atheroscler Rep. 2004 Jul;6(4):281-7
references.pmid: 15191702
references.citation: J Clin Invest. 1986 Dec;78(6):1456-61
references.pmid: 3491092
references.citation: Med Hypotheses. 2000 Dec;55(6):480-4
references.pmid: 11090294
references.citation: Arterioscler Thromb Vasc Biol. 1998 May;18(5):708-16
references.pmid: 9598828
references.citation: Am J Cardiol. 1990 Dec 1;66(19):1368-72
references.pmid: 2244569
references.citation: Circ Res. 1983 Oct;53(4):502-14
references.pmid: 6627609
references.citation: Ann Biomed Eng. 2004 Dec;32(12):1628-41
references.pmid: 15675676
references.citation: Stroke. 1997 May;28(5):993-8
references.pmid: 9158640
references.citation: JAMA. 1999 Dec 1;282(21):2035-42
references.pmid: 10591386
references.citation: J Biomech Eng. 1992 Aug;114(3):274-82
references.pmid: 1522720
references.citation: Biochem Biophys Res Commun. 2006 Mar 24;341(4):1244-51
references.pmid: 16466697
references.citation: J Biol Chem. 1995 Oct 6;270(40):23352-61
references.pmid: 7559492
references.citation: J Am Coll Cardiol. 2005 Mar 15;45(6):846-54
references.pmid: 15766817
references.citation: Am Heart J. 2002 Jun;143(6):931-9
references.pmid: 12075241
references.citation: J Biomech. 1993 Feb;26(2):133-42
references.pmid: 8429056
references.citation: Lab Invest. 2005 Jan;85(1):9-23
references.pmid: 15568038
references.citation: J Biomech. 2003 Aug;36(8):1185-96
references.pmid: 12831745
references.citation: Ann Biomed Eng. 1994 Sep-Oct;22(5):445-55
references.pmid: 7825747
references.citation: Phys Med Biol. 2003 Jan 7;48(1):127-38
references.pmid: 12564505
references.citation: Am J Physiol. 1980 Jul;239(1):H14-21
references.pmid: 7396013
references.citation: Curr Opin Cardiol. 2000 Nov;15(6):430-40
references.pmid: 11198626
references.citation: Blood. 1996 Sep 1;88(5):1525-41
references.pmid: 8781407
references.citation: J Biomech. 2003 May;36(5):681-8
references.pmid: 12694998
references.citation: Circ Res. 1968 Feb;22(2):165-97
references.pmid: 5639037
references.citation: Ann Biomed Eng. 2006 Mar;34(3):393-407
references.pmid: 16477502
references.citation: Clin Sci. 1971 Feb;40(2):5P
references.pmid: 5548533
references.citation: Science. 1986 Jan 24;231(4736):405-7
references.pmid: 3941904
references.citation: Yonsei Med J. 1998 Apr;39(2):166-74
references.pmid: 9587258
references.citation: Arterioscler Thromb. 1991 Nov-Dec;11(6):1844-52
references.pmid: 1931886
references.citation: Ann Biomed Eng. 1995 Nov-Dec;23(6):787-93
references.pmid: 8572428
references.citation: Circulation. 1993 Apr;87(4):1179-87
references.pmid: 8462145
references.citation: Am J Cardiol. 1994 Mar 1;73(7):431-7
references.pmid: 8141082
references.citation: Physiol Rev. 1995 Jul;75(3):519-60
references.pmid: 7624393
references.citation: Stroke. 1984 Jan-Feb;15(1):50-6
references.pmid: 6695430
references.citation: Arteriosclerosis. 1989 Nov-Dec;9(6):842-7
references.pmid: 2590063
references.citation: Atherosclerosis. 1993 Jan 25;98(2):193-9
references.pmid: 7681291