Abstract: A prosthetic cardiac valve with a plurality of flaps supported by a base through a rotational guide and retaining mechanism between an open position and a closed position.The valve is characterized in that:the guide and retaining mechaism define a virtual axis of rotation disposed at a distance from the axis of the valve which is greater than 75% of the radius of the base measured along the axis of symmetry of a flap,each virtual axis, situated outside the corresponding flap, is offcentered with respect to the center of gravity of the flap, andin the open position, the corners of each flap come to bear on the internal wall of the base in zones which are situated at a distance from the corresponding virtual axis of rotation which is greater than 25% of the radius of the base.