An implantable medical device (IMD) can include implantable pulse generator (IPG) devices, implantable cardioverter-defibrillators (ICD), cardiac resynchronization therapy defibrillator devices, neurostimulators or combinations thereof. In one example, the IMD can include a body assembly, which can provide at least one electrical signal corresponding to a therapy. The IMD can also include a cardiac lead assembly, which can have a proximal portion and a distal portion. The proximal portion of the cardiac lead assembly can be in communication with the body assembly to receive the therapy and the distal portion can be adapted to be coupled to an anatomical structure to transmit the at least one electrical signal to the anatomical structure. The proximal portion of the cardiac lead assembly can have a first stiffness and the distal portion can have a second stiffness. The first stiffness can be greater than the second stiffness.
