A delivery device for an implantable medical device includes an inner shaft extending in a longitudinal direction and an outer sheath adapted to surround at least a portion of the inner shaft, the outer sheath being slideable relative to the inner shaft in the longitudinal direction. A compartment defined between the inner shaft and the outer sheath is adapted to receive the medical device in an assembled condition. A retaining assembly positioned at one end of the compartment includes a first member rotatable with respect to the inner shaft, and a second member rotationally fixed with respect to the inner shaft. The medical device includes at least one retainer adapted to be received within at least one retainer slot of the first member. This arrangement enables the medical device to rotate within the compartment as the delivery device is advanced to an implantation site.
