Abstract: An expandable intravascular medical device is provided. The medical device comprises an arcuate spring configured to be expanded into firm contact with the inner surface of a blood vessel. The medical device further comprises at least one electrode associated with the arcuate spring. For example, the electrode(s) can be discrete elements that are bonded to the arcuate spring, electrically conductive layers disposed on the arcuate spring, or the arcuate spring, itself, can form the electrode(s). The inner surface of the arcuate spring may optionally be electrically insulative. An intravascular medical device is provided. In one embodiment, the medical device comprises an electrode support structure, e.g., a non-tubular arcuate structure or a cylindrical member, and a plurality of resilient spring loops laterally extending from the support structure. The contact created between the loops and a blood vessel are sufficient to anchor the medical device within the blood vessel.