A capsule includes a tubular body with, at its proximal end, a coupling member adapted to cooperate with a conjugated coupling member mounted at the distal end of a catheter of the implantation tool, for the transmission of a torque for the rotational driving of the capsule by the catheter. The coupling member of the tool includes a dihedral-shaped imprint, with two diverging arms in a V-arrangement, and the capsule coupling member includes a convex surface adapted to frictionally and slidingly urge against the diverging arms of the V-shape.
