Prosthetic heart valve

Abstract

A bileaflet heart valve is shown which incorporates a pivot arrangement that minimizes resistance to downstream blood flow in the open position yet has prompt response and therefore minimal regurgitation upon flow reversal. The valve employs a pair of identical flat leaflets that can assume a precisely parallel orientation in the fully open position at or near peak downstream blood flow or can alternatively assume other low energy positions. As the downstream flow of blood slows near the end of a pumping stroke, downstream displacement of the leaflets results in their prerotation toward the closed position orientation, all being controlled by the interengagement of flat ears, which extend laterally from opposite surfaces of the leaflets, and receiving cavities of unique design. The cavities include upstream and downstream lobes separated by an intermediate throat portion defined by inward and outward fulcrums. As soon as reverse flow begins, upstream displacement of the leaflets causes the ears to contact straight camming surfaces located upstream of the outward fulcrums which, in combination with the fulcrums and a downwardly directed, concave surface at the upstream end of the upstream lobe, positively guide each leaflet through efficient closing which ends in substantially rotational movement.