Leadless cardiac pacing devices

1. An implantable leadless pacing device, comprising: a pacing capsule including a cylindrical housing, the cylindrical housing having a proximal end, a proximal region extending to the proximal end, a distal end, a distal region extending to the distal end, a central longitudinal axis extending through the proximal and distal ends, and a circumferential surface extending longitudinally between the proximal region and the distal region and surrounding the central longitudinal axis;

a first electrode disposed along the distal region;

an anchoring member coupled to the distal region, wherein the anchoring member includes a helical screw extending through greater than 360 degrees of rotation; and

a plurality of anti-rotation members fixedly attached to the distal region and arranged circumferentially around the helical screw, the plurality of anti-rotation members extending radially outward beyond the circumferential surface adapted to engage a wall of a heart or otherwise entwine with trabeculae of the heart, and

wherein the plurality of anti-rotation members have distal ends which extend distal of a distal extent of the helical screw when in an unconstrained configuration;

wherein the first electrode is disposed radially within and spaced apart from the helical screw.

2. The implantable leadless pacing device of claim 1 , wherein at least some of the plurality of anti-rotation members include a curved region.

3. The implantable leadless pacing device of claim 1 , wherein at least some of the plurality of anti-rotation members have a substantially circular cross-sectional shape.

4. The implantable leadless pacing device of claim 1 , wherein at least some of the plurality of anti-rotation members have a polygonal cross-sectional shape.

5. The implantable leadless pacing device of claim 1 , wherein at least some of the plurality of anti-rotation members are capable of pivoting relative to the housing.

6. An implantable leadless pacing device system, the system comprising:

a delivery catheter having a proximal section, a distal holding section, and a lumen formed therein;

a push member slidably disposed within the lumen;

a leadless pacing device slidably received within the distal holding section, the leadless pacing device comprising:

a housing having a proximal end, a proximal region extending to the proximal end, a distal end, a distal region extending to the distal end, a longitudinal axis extending through the proximal and distal ends, and a peripheral surface extending longitudinally between the proximal region and the distal region and surrounding the longitudinal axis,

a first electrode disposed along the distal region,

an anchoring member coupled to the distal region, and

one or more anti-rotation members fixedly attached to the distal region and extending radially outward beyond the peripheral surface of the housing in an unconstrained configuration,

wherein the one or more anti-rotation members each has a distal end which extends distal of a distal extent of the anchoring member when in the unconstrained configuration,

wherein each of the one or more anti-rotation members is engaged with an inner surface of the distal holding section and moved away from the unconstrained configuration into a constrained configuration oriented in a distal direction for advancement of the delivery catheter;

wherein the first electrode is disposed radially within and spaced apart from the anchoring member.

7. The system of claim 6 , wherein a docking member is coupled to the proximal region of the housing, the docking member being adapted to operably engage the push member.

8. The system of claim 7 , wherein the push member is capable of rotating the housing when the push member is engaged with the docking member.

9. The system of claim 6 , wherein at least some of the one or more anti-rotation members include a curved region.

10. The system of claim 6 , wherein at least some of the one or more anti-rotation members are capable of pivoting relative to the housing.

11. The system of claim 6 , wherein the anchoring member includes a helical screw extending through greater than 360 degrees of rotation.

12. An implantable leadless pacing device, comprising:

a pacing capsule including a housing, the housing having a proximal end, a proximal region extending to the proximal end, a distal end, a distal region extending to the distal end, a central longitudinal axis extending through the proximal and distal ends, and a peripheral surface extending longitudinally between the proximal region and the distal region and surrounding the central longitudinal axis, the peripheral surface located at a first distance away from the central longitudinal axis, the first distance measured perpendicular to the central longitudinal axis;

a first electrode disposed along the distal region;

an anchoring member coupled to the distal region, wherein the anchoring member includes a helical screw; and

a plurality of anti-rotation members fixedly attached to the distal region and adapted to engage a wall of a heart or otherwise entwine with trabeculae of the heart,

wherein the plurality of anti-rotation members are circumferentially arranged around the helical screw and extend radially outward of the helical screw and beyond the peripheral surface of the housing,

wherein in an unconstrained state, each of the plurality of anti-rotation members is configured to have a distal end which extends distal of a distal extent of the helical screw; and

wherein in the unconstrained state, the distal end of each of the plurality of anti-rotation members is positioned at a second distance away from the central longitudinal axis, the second distance measured perpendicular to the central longitudinal axis, wherein the second distance is greater than the first distance;

wherein the helical screw is disposed circumferentially around the first electrode and spaced therefrom.

13. The implantable leadless pacing device of claim 12 , wherein the helical screw extends through greater than 360 degrees of rotation.

14. The implantable leadless pacing device of claim 12 , wherein each of the plurality of anti-rotation members has a base that is fixedly attached to the distal region and are capable of pivoting about the base to move the anti-rotation member relative to the housing.

15. The implantable leadless pacing device of claim 12 , wherein the peripheral surface is a cylindrical surface.

16. The implantable leadless pacing device of claim 12 , wherein the helical screw extends through at least 720 degrees of rotation.