The invention includes an implantable medical electrical lead for electrical stimulation of body tissue that includes at least one modifiable portion that exhibits a first configuration when exposed to a first temperature and a second configuration when exposed to a second temperature, wherein the second configuration of the modifiable portion exhibits a greater resistance to movement of the lead within the body tissue than does the first configuration, and the second temperature is higher than the first temperature and at least one electrode configured to provide electrical stimulation of body tissue, wherein the lead has a proximal end and a distal end. Systems including leads of the invention and methods of implanting leads of the invention are also included.
