A valve prosthesis configured to replace a mitral or tricuspid heart valve, comprising: a valve body ; and a frame including a first tubular portion connected to the valve body , and a second tubular portion configured to contact and conform to a native valve annulus in situ, the frame having a delivery configuration in which the first tubular portion is positioned in series with the second tubular portion along a longitudinal axis of the frame and the first tubular portion is longitudinally adjacent to the second tubular portion , and an expanded configuration in which the first tubular portion is positioned within an interior area of the second tubular portion , such that the second tubular portion surrounds the first tubular portion and both of the first tubular portion and the second tubular portion extend parallel to the longitudinal axis of the frame , wherein the first tubular portion and the second tubular portion of the frame are connected to each other by a third portion of the frame extending between the first tubular portion and the second tubular portion , wherein the first tubular portion is longitudinally separated from the second tubular portion by the third portion when the frame is in the delivery configuration, and wherein the third portion at least partially radially extends between the first tubular portion and the second tubular portion when the frame is in the expanded configuration, wherein the third portion of the frame comprises a plurality of connecting arms having first ends attached to the first tubular portion of the frame and second ends attached to the second tubular portion of the frame . a valve body ; and a frame including a first tubular portion connected to the valve body , and a second tubular portion configured to contact and conform to a native valve annulus in situ, the frame having a delivery configuration in which the first tubular portion is positioned in series with the second tubular portion along a longitudinal axis of the frame and the first tubular portion is longitudinally adjacent to the second tubular portion , and an expanded configuration in which the first tubular portion is positioned within an interior area of the second tubular portion , such that the second tubular portion surrounds the first tubular portion and both of the first tubular portion and the second tubular portion extend parallel to the longitudinal axis of the frame , wherein the first tubular portion and the second tubular portion of the frame are connected to each other by a third portion of the frame extending between the first tubular portion and the second tubular portion , wherein the first tubular portion is longitudinally separated from the second tubular portion by the third portion when the frame is in the delivery configuration, and wherein the third portion at least partially radially extends between the first tubular portion and the second tubular portion when the frame is in the expanded configuration, wherein the third portion of the frame comprises a plurality of connecting arms having first ends attached to the first tubular portion of the frame and second ends attached to the second tubular portion of the frame . <EOS>