Leadless cardiac pacemaker with delivery and/or retrieval features

1. An implantable leadless cardiac pacing device comprising:

a housing having a proximal end and a distal end;

an electrode positioned proximate the distal end of the housing configured to be positioned adjacent cardiac tissue; and

a docking member extending from the proximal end of the housing along a longitudinal axis of the housing, the docking member configured to facilitate retrieval of the implantable leadless cardiac pacing device;

the docking member including a head portion and a neck portion extending between the housing and the head portion;

the head portion having a radial dimension from the longitudinal axis and the neck portion having a radial dimension from the longitudinal axis less than the radial dimension of the head portion;

the head portion including a plurality of radially extending spokes extending radially outward from the longitudinal axis of the housing;

wherein each spoke includes a base portion proximate the longitudinal axis of the housing and a free end extending radially outward from the base portion, wherein a width of each spoke increases from the base portion toward the free end of the spoke.

2. The implantable leadless cardiac pacing device of claim 1 , wherein each of the spokes extends at an oblique angle to the longitudinal axis of the housing toward the distal end such that the free ends of the plurality of spokes are positioned closer to the distal end of the housing than the base portion of the spokes proximate the longitudinal axis of the housing.

3. The implantable leadless cardiac pacing device of claim 1 , wherein the plurality of spokes are configured to mate with an engagement mechanism of a rotational driving instrument to transfer rotational torque to the implantable leadless cardiac pacing device.

4. An implantable leadless cardiac pacing device comprising:

a housing having a proximal end and a distal end;

an electrode positioned proximate the distal end of the housing configured to be positioned adjacent cardiac tissue; and

a docking member extending from the proximal end of the housing along a longitudinal axis of the housing, the docking member configured to facilitate retrieval of the implantable leadless cardiac pacing device;

the docking member including a head portion and a neck portion extending between the housing and the head portion;

the head portion having a radial dimension from the longitudinal axis and the neck portion having a radial dimension from the longitudinal axis less than the radial dimension of the head portion;

the head portion including a plurality of radially extending spokes extending radially outward from the longitudinal axis of the housing;

wherein each of the spokes includes a body portion extending radially outward to a free end of the spoke and a crossing member extending transverse to the body portion.

5. The implantable leadless cardiac pacing device of claim 4 , wherein the crossing member extends in opposite directions from the body portion.

6. The implantable leadless cardiac pacing device of claim 5 , wherein the spoke is T-shaped.

7. The implantable leadless cardiac pacing device of claim 5 , wherein each spoke includes undercut portions at a junction between the crossing member and the body portion of the spoke.

8. A system for retrieving an implantable leadless cardiac pacing device, comprising:

an implantable cardiac pacing device having a housing having a longitudinal axis, 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, the head portion including a plurality of radially extending spokes extending radially outward from the longitudinal axis of the housing; and

a retrieval device including a snare having an elongate shaft and one or more loops at a distal end of the elongate shaft;

wherein the one or more loops of the retrieval device are capable of encircling one or more of the radially extending spokes to capture the docking member with the snare;

wherein each spoke includes:

i) a base portion proximate the longitudinal axis of the housing and a free end extending radially outward from the base portion, wherein a width of each spoke increases from the base portion toward the free end of the spoke; or

ii) a body portion extending radially outward to a free end of the spoke and a crossing member extending transverse to the body portion.

9. The system of claim 8 , wherein if the spoke includes ii), the crossing member extends in opposite directions from the body portion.

10. The system of claim 9 , wherein the spoke is T-shaped.

11. The system of claim 9 , wherein each spoke includes undercut portions at a junction between the crossing member and the body portion of the spoke.

12. The system of claim 8 , wherein if the spoke includes i), each of the spokes extends at an oblique angle to the longitudinal axis of the housing toward the distal end such that the free ends of the plurality of spokes are positioned closer to the distal end of the housing than the base portion of the spokes proximate the longitudinal axis of the housing.