The invention relates to a medical implantable lead of the kind being adapted to be implanted into a human or animal body for monitoring and/or controlling of an organ inside the body. The lead comprises in a distal end a tubular header (3) inside which a shaft (7) is rotatable as well as extendable and retractable arranged and carries in a distal end a combined fixation means and electrode member in form of a helix (4), which is provided with a first contact surface being electrically connectible to a connector at the proximal end of the lead by means of an electric conductor (8), and which by means of the shaft is rotatable in relation to the lead and extendable out from the distal end to be able to fixate the distal end of the lead to the organ by being screwed into the tissue. The shaft also carries a second contact surface (13) being positioned on or adjacent a proximal portion of the helix and being connectible to a connector at the proximal end of the lead by means of an electric conductor (8). The lead comprises a conduction controlling means (14), which at least during an initial stage after implantation is capable of render the first contact surface electrically inactive and which is capable of render the first contact surface electrically active after the initial stage. By means of the inventive lead it is possible to detect whether the helix is sufficient screwed into the tissue (12) or not.