A medical device lead assembly includes an end connector element having a plurality of fixed connection element tabs each respectively extending from the end connector element to a tab distal end, and a lead body having a plurality of lead filars extending through the lead body and forming a filar coil. Each of the plurality of lead filars is coupled to a corresponding fixed connection tab. Each of the plurality of lead filars have a diameter of less than 150 micrometers or less than 125 micrometers, or from 50 to 125 micrometers or from 50 to 100 micrometers. The filar coil having an outer diameter value being less than 1.5 mm and a first pitch within the lead body and a second pitch adjacent to the end connector element and the second pitch is greater than the first pitch.