Aortic Valve Leaflet Motion during Systole

An approximate numerical^graphical solution was made for the motion of a human aortic valve leaflet in a meridional plane through the center of the sinus of Vabalva. The observed buckling, whipping action of the leaflet was obtained. Of primary significance in the results was the location and the determination of the maximum curvature of the leaflet in this plane, since this point corresponds to the point of maximum fatigue bending stress. The approximate dimensionless curvature was on the order of 3.5 (referred to the aortic diameter) at a dimensionless radial location of 0.55-0.6. The most important feature determining leaflet curvature and morion was the initial contour shape. The initial shape of a normal human leaflet produces smaller curvatures than the curved shapes usually illustrated for aortic valves. KEY' WORDS human trileaflet and aortic valve motion curvature of valve leaflets during systole leaflet motion dynamics buckling of membrane valves fatigue stress bnckling of aortic valve • Some observations on the aortic valve during opening have indicated a wavy, buckling, whipping, flutter motion of the leaflets. If such a motion exists, bending fatigue stresses would be produced. It has been observed also that trileaflet prostheses fail at a location in the leaflet that could correspond to the point of maximum bending stress. An approximate numerical-graphical determination of valve motion is presented that indicates this motion in a meridional plane through the sinus of Valsalva.