A medical device lead includes a flexible body having a proximal region with a proximal end, and a distal region with a distal end. A connector is coupled to the proximal end of the flexible body of the lead to electrically and mechanically connect the lead to an implantable pulse generator. The medical device lead also includes an electrode in the distal region of the flexible body, and a cable conductor having a proximal end electrically coupled to the connector and a distal end electrically coupled to the electrode. The cable conductor consists of a single helically coiled filar including a plurality of co-radial turns and having an outer diameter of less than about 0.020 inch (0.508 mm).