Medical electrical leads are provided including fixation features for acute and chronic fixation of a portion of the respective leads within the cardiac venous system. The medical electrical lead includes an elongate body having proximal and distal regions. Tissue contacting portions are selectively located in the distal region to contact an inner surface of the cardiac vessel when the lead is in an implanted position. The tissue contacting portion(s) include fixation features adapted to frictionally engage the inner surface of the cardiac vessel and promote tissue in-growth for chronic fixation. In some embodiments, the fixation features are detachable from the lead such that the lead can be extracted from its implanted position after tissue in-growth occurs.