Device (10) for implantation in the heart (50) of a mammal, generally tubular (11) and having a longitudinal axis (12), a first end (13) and a second end (14) and a cavity (15) that allows the blood flow to pass through it, in which the device (10) consists of - A first tubular stent element (16), of dimensions and configured for implantation in the superior vena cava (52), and having a length (17), a diameter (18), a first (19) and a second end (20), - A second tubular stent element (22), of dimensions and configured for implantation in the vena cava lower (53), and having a length (23), a diameter (24), a first (25) and a second end (26), wherein said second tubular element of the stent (22) does not consist of a protection, - A tubular element of the stent (30), which has a length (31), a diameter (32), a first (33) and a second end of the stent element (34), and qu and comprises a protection (35) that sticks or adheres to a stent element (36), where the stent tubular element (30) is firmly connected between the first (16) and the second stent tubular element (22) , so that the second end of the stent element (34) adheres to the first end of the first stent element (19), and the first end of the stent element (33) adheres to the second end of the second element of the stent stent (26), where the stent element (30) has a size and has been configured for implantation in the right atrium (54) of the mammal's heart (50)； and - A stenosed valve element (40) comprising a stent element (41) and a valve (42), the valve (42) being mounted on the stent element (41), in which the element of the Stenosed valve (40) is firmly mounted on the stent element (30), in which the valve element (40) is unidirectional, allowing blood to flow from the vena cava to the right atrium while blocking the flow of blood in the opposite direction.Dispositivo (10) para la implantación en el corazón (50) de un mamífero, de forma generalmente tubular (11) y que tiene un eje longitudinal (12), un
