A lead has a helix at a distal end of a rotatable shaft. Prior to implantation of the lead, the helix has a first configuration comprising an electrically active surface coated with an electrically insulative layer of a biologically dissolvable material to render the helix electrically inactive. Upon fixation of the helix into an organ, the helix has the first configuration and a pin is in electrical contact with the organ to detect proper fixation of the helix into the organ. Subsequent to fixation of the helix into the organ, the helix has a second configuration comprising an electrically active surface exposed upon dissolving of the electrically insulative layer of the biologically dissolvable material to render the helix electrically active.