title: Coronary Flow Impacts Aortic Leaflet Mechanics and Aortic Sinus Hemodynamics.
abstract: Mechanical stresses on aortic valve leaflets are well-known mediators for initiating processes leading to calcific aortic valve disease. Given that non-coronary leaflets calcify first, it may be hypothesized that coronary flow originating from the ostia significantly influences aortic leaflet mechanics and sinus hemodynamics. High resolution time-resolved particle image velocimetry (PIV) measurements were conducted to map the spatiotemporal characteristics of aortic sinus blood flow and leaflet motion with and without physiological coronary flow in a well-controlled in vitro setup. The in vitro setup consists of a porcine aortic valve mounted in a physiological aorta sinus chamber with dynamically controlled coronary resistance to emulate physiological coronary flow. Results were analyzed using qualitative streak plots illustrating the spatiotemporal complexity of blood flow patterns, and quantitative velocity vector and shear stress contour plots to show differences in the mechanical environments between the coronary and non-coronary sinuses. It is shown that the presence of coronary flow pulls the classical sinus vorticity deeper into the sinus and increases flow velocity near the leaflet base. This creates a beneficial increase in shear stress and washout near the leaflet that is not seen in the non-coronary sinus. Further, leaflet opens approximately 10% farther into the sinus with coronary flow case indicating superior valve opening area. The presence of coronary flow significantly improves leaflet mechanics and sinus hemodynamics in a manner that would reduce low wall shear stress conditions while improving washout at the base of the leaflet.
authors: Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, 80523-1374, USA.
authors: Brandon L
authors: BL
authors: Moore
authors: Lakshmi Prasad
authors: LP
authors: Dasi
mesh_terms: D001021:Aortic Valve / Q000502:physiology*; D001783:Blood Flow Velocity; D006801:Humans; D008955:Models, Cardiovascular; D012850:Sinus of Valsalva / Q000502:physiology*
references: Circ Res. 1990 Aug;67(2):448-60
references: 2376081
references: Am J Cardiol. 1993 Feb 1;71(4):322-7
references: 8427176
references: Comput Math Methods Med. 2012;2012:791686
references: 22474538
references: Arterioscler Thromb Vasc Biol. 2009 Feb;29(2):254-60
references: 19023092
references: PLoS One. 2012;7(10):e48843
references: 23119099
references: Biomech Model Mechanobiol. 2012 Sep;11(7):1085-96
references: 22294208
references: J Heart Valve Dis. 2013 Sep;22(5):688-96
references: 24383382
references: Eur J Cardiothorac Surg. 2004 Jul;26(1):66-72
references: 15200981
references: Heart Surg Forum. 2004;7(6):E577-83
references: 15769691
references: Annu Rev Biomed Eng. 1999;1:299-329
references: 11701491
references: Circulation. 2014 Jan 21;129(3):e28-e292
references: 24352519
references: Surg Radiol Anat. 2009 Oct;31(8):597-604
references: 19288041
references: Cardiovasc Eng. 2010 Mar;10(1):5-11
references: 20107896
references: Circulation. 2005 Jun 21;111(24):3316-26
references: 15967862
references: J Biomech Eng. 2011 Jun;133(6):061007
references: 21744927
references: Arterioscler Thromb Vasc Biol. 2004 Aug;24(8):1331-3
references: 15297285
references: Circulation. 1983 Aug;68(2):337-47
references: 6602669
references: Circulation. 2005 Feb 22;111(7):920-5
references: 15710758
references: Biomech Model Mechanobiol. 2012 Jan;11(1-2):171-82
references: 21416247
references: J Biomech. 2008;41(3):595-602
references: 18036532
references: Circulation. 1996 Apr 15;93(8):1502-8
references: 8608617
references: ASAIO J. 2014 Sep-Oct;60(5):545-52
references: 25010918
references: Int J Inflam. 2011;2011:263870
references: 21760982
references: Exp Fluids. 2014 Jun 1;55(7):1770
references: 25067881
references: Thromb Res. 1998 Dec 15;92(6 Suppl 2):S25-31
references: 9886907