Medical electrical lead systems and related methods are described. The medical electrical lead systems may be configured to be at least partially implanted in a body of a subject. Some variations of the medical electrical lead systems may comprise a lead body comprising a proximal end and a distal end and a lumen extending at least partially therebetween, at least one electrode in the proximity of the distal end of the lead body, and a reservoir in fluid communication with the lumen, where the reservoir is located at a position removed from the distal end of the lead body. Certain variations of the medical electrical lead systems may comprise a lead body comprising a proximal end and a distal end and first and second lumens extending at least partially therebetween, and at least one electrode in the proximity of the distal end of the lead body.