An assembly for retrieving an implantable cardiac pacing device, comprising: an implantable cardiac pacing device having a housing, an electrode positioned proximate a distal end of the housing, and a docking member extending from a proximal end of the housing opposite the distal end, the docking member including a head portion and a neck portion extending between the housing and the head portion; and a retrieval device including: a retrieval catheter having a proximal end, a distal end, and a lumen extending into the retrieval catheter from the distal end; a snare advanceable from the distal end of the retrieval catheter, the snare having a loop configured to be coupled to the docking member to draw the implantable cardiac pacing device into the lumen of the retrieval catheter; wherein the retrieval catheter includes a retention feature (140, 150, 160, 170, 180) in the lumen configured to engage the head portion of the docking member to facilitate retention of the implantable cardiac pacing device in the lumen after drawing the implantable cardiac pacing device into the lumen of the retrieval catheter with the snare, characterised in that the retention feature extends radially inward from an inner surface of the catheter. an implantable cardiac pacing device having a housing, an electrode positioned proximate a distal end of the housing, and a docking member extending from a proximal end of the housing opposite the distal end, the docking member including a head portion and a neck portion extending between the housing and the head portion; and a retrieval device including: a retrieval catheter having a proximal end, a distal end, and a lumen extending into the retrieval catheter from the distal end; a snare advanceable from the distal end of the retrieval catheter, the snare having a loop configured to be coupled to the docking member to draw the implantable cardiac pacing device into the lumen of the retrieval catheter; wherein the retrieval catheter includes a retention feature (140, 150, 160, 170, 180) in the lumen configured to engage the head portion of the docking member to facilitate retention of the implantable cardiac pacing device in the lumen after drawing the implantable cardiac pacing device into the lumen of the retrieval catheter with the snare, characterised in that the retention feature extends radially inward from an inner surface of the catheter. a retrieval catheter having a proximal end, a distal end, and a lumen extending into the retrieval catheter from the distal end; a snare advanceable from the distal end of the retrieval catheter, the snare having a loop configured to be coupled to the docking member to draw the implantable cardiac pacing device into the lumen of the retrieval catheter; wherein the retrieval catheter includes a retention feature (140, 150, 160, 170, 180) in the lumen configured to engage the head portion of the docking member to facilitate retention of the implantable cardiac pacing device in the lumen after drawing the implantable cardiac pacing device into the lumen of the retrieval catheter with the snare, characterised in that the retention feature extends radially inward from an inner surface of the catheter.