In one example, this disclosure is directed to a kit for intravascular implantation of an implantable medical device within a patient, the kit comprising an elongated outer sheath forming a first inner lumen with a distal opening, the outer sheath sized to traverse a vasculature of the patient, and an elongated inner sheath forming a second inner lumen. An outer diameter of the inner sheath is smaller than the diameter of the first inner lumen such that the inner sheath fits within the first inner lumen, wherein the inner sheath is slidable within the first inner lumen. The second inner lumen at a distal end of the inner sheath is configured to carry an implantable medical device. The inner sheath forms a slit at a distal end of the inner sheath to facilitate deployment of the implantable medical device out of the distal opening of the outer sheath.