A device for implanting a heart prosthesis including a central body, a containment portion having one or more sub-components, and a release device for the central body capable of being inserted into a catheter. A device for assisting the connection operation between the central body and the sub-components of the containment portion includes an assembly of catheters, of which there are at least two catheters for each sub-component of the containment portion, the catheters being joined to each other over a portion thereof and having at least one free end for each catheter.