A anchor for an implantable medical device includes an anchor body and a locking member. The anchor body includes a first trough extending along a first axis. The locking member is coupled to the anchor body and rotates with respect to a second axis, between an unlocked position and a locked position. The locking member includes protruding members that define a second trough aligned with the first trough when the locking member is rotated to the unlocked position, so as to form an open path for the implantable medical device to move through the first and second troughs. When the locking member is rotated to the locked position, the protruding members block at least a portion of the first trough to define a tortuous path between the first trough and the second trough so as to restrict a movement of the implantable medical device through the first and second troughs.