Abstract: Disclosed is a heart valve of the bi-leaflet type having an improved hinge arrangement that allows the valve to respond more quickly to flow reversal and minimizes fluttering of the leaflets in the open position. The leaflets are slidably and pivotally mounted in a heart valve body for movement between closed and open positions. The leaflets have notches which matingly engage complementary surfaces on pivot projections extending inward from the valve body sidewall. The shape and relationship of these complementary surfaces provides for improved operating characteristics.