Set for installing an intracardiac stimulation or defibrillation lead equipped with a screw

A set for installing an intracardiac lead of the “screw-in lead” type into a wall of the endocardium, comprising:

• a lead-body having a flexible hollow sheath, a distal extremity and a proximal extremity, a lead-head at the distal extremity, the lead-head comprising at least one stimulating electrode and a screw, the lead-head being rotatable to allow anchoring said screw into a wall of the endocardium:
• and
• a removable stylet sized to be introduced inside said sheath and mobile in translation and rotation inside said sheath, said stylet having a distal extremity;
• a means for coupling in rotation, located at said stylet distal extremity, to allow said rotation of the lead-head;
• a central core having a first length, a distal extremity and a proximal extremity, said means for coupling in rotation being sized to couple to said core distal extremity;
• a handling body coupled to said core proximal extremity;
• and a hollow tube axially placed around the core, said hollow tube having a second length that is shorter than said core first length, so that said central core emerges from the hollow tube at digital and proximal extremities of the tube, so as to allow the rotation of the core and correlatively the means for coupling, by action on the handling body, primarily without setting in rotation of the hollow tube,
• wherein said central core comprises a material selected so that any torque likely to be transmitted by the core is higher than a minimal torque of rotation associated with a rotation of said lead-head, and lower than a resistive torque associated with the lead-head being anchored in the wall of the endocardium, whereby, after a predetermined number of turns corresponding to a complete operation of deployment and screwing of the screw, any additional rotation of the core results in a twist of the core inside the tube, primarily without increase in the couple transmitted by means for coupling in rotation.