Disclosed is a mechanical prosthetic heart valve. The valve has an annular support (12) having an internal peripheral surface (16) centred on a longitudinal axis (X). At least two mobile flaps (18, 20, 22) are articulated to the internal peripheral surface of the support so that each is able to rotate about a flap rotation axis perpendicular to the longitudinal axis (X) from an open position and a closed position of the valve. The annular support has an edge (30) on the downstream side of the anterograde flow, called the downstream edge, and a plurality of articular extensions (32, 34, 36) that extend axially from the downstream edge and the number of which corresponds to the number of flaps. Each flap has a central part symmetrically bracketed by two lateral wings (40, 42) that are inclined relative to this central part. The two wings respectively cooperate, to allow rotation of the flap, with the internal surfaces of two articular extensions via a so-called terminal portion of each wing. Each terminal portion has an exterior surface, called the articulation facet, which when the flap is open comes to bear against a portion of the internal surface of the corresponding articular extension.
