Editing Vortex ring (section)

===In the human heart===
A vortex ring is formed in the left [[ventricle (heart)|ventricle]] of the [[human heart]] during cardiac relaxation ([[diastole]]), as a [[jet (fluid)|jet]] of [[blood]] enters through the [[mitral valve]]. This phenomenon was initially observed [[in vitro]]<ref>Bellhouse, B.J., 1972, ''Fluid mechanics of a model mitral valve and left ventricle'', Cardiovascular Research 6, 199–210.</ref><ref>Reul, H., Talukder, N., Muller, W., 1981, ''Fluid mechanics of the natural mitral valve'', Journal of Biomechanics 14, 361–372.</ref> and subsequently strengthened by analyses based on [[color Doppler mapping]]<ref>Kim, W.Y., Bisgaard, T., Nielsen, S.L., Poulsen, J.K., Pedersen, E.M., Hasenkam, J.M., Yoganathan, A.P., 1994, ''Two-dimensional mitral flow velocity profiles in pig models using epicardial echo Doppler Cardiography'', J Am Coll Cardiol 24, 532–545.</ref><ref>Vierendeels, J. A., E. Dick, and P. R. Verdonck, ''Hydrodynamics of color M-mode Doppler flow wave propagation velocity V(p): A computer study'', J. Am. Soc. Echocardiogr. 15:219–224, 2002.</ref> and [[magnetic resonance imaging]].<ref>Kim, W.Y., Walker, P.G., Pedersen, E.M., Poulsen, J.K., Oyre, S., Houlind, K., Yoganathan, A.P., 1995, ''Left ventricular blood flow patterns in normal subjects: a quantitative analysis by three dimensional magnetic resonance velocity mapping'', J Am Coll Cardiol 26, 224–238.</ref><ref>Kilner, P.J., Yang, G.Z., Wilkes, A.J., Mohiaddin, R.H., Firmin, D.N., Yacoub, M.H., 2000, ''Asymmetric redirection of flow through the heart'', Nature 404, 759–761.</ref> Some recent studies<ref>Kheradvar, A., Milano, M., Gharib, M. ''Correlation between vortex ring formation and mitral annulus dynamics during ventricular rapid filling'', ASAIO Journal, Jan–Feb 2007 53(1): 8–16.</ref><ref>Kheradvar, A., Gharib, M. ''Influence of ventricular pressure-drop on mitral annulus dynamics through the process of vortex ring formation'', Ann Biomed Eng. 2007 Dec;35(12):2050–64.</ref> have also confirmed the presence of a vortex ring during [[rapid filling]] phase of [[diastole]] and implied that the process of vortex ring formation can influence [[mitral annulus]] dynamics.