Leadless Pacemaker with Radial Fixation Mechanism

• US 20120158111A1
• Filed: 12/20/2011
• Published: 06/21/2012
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: PASPA, Paul, KHAIRKHAHAN, Alexander, OSTROFF, Alan, VARADY, Eric
• Granted Patent: US 9,242,102 B2
• Time in Patent Office: Days
• US Class Current: 607/127
• CPC Class Codes: A61N 1/057 Anchoring means; Means for fixing the head inside the heart
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

A leadless cardiac pacemaker having a radial fixation mechanism is provided. The cardiac pacemaker can include fixation mechanism separate from a pacing electrode and having a diameter equal to or less than the outer diameter of the pacemaker. The fixation mechanism can allow the pacemaker to be inserted into tissue with less than 2 rotations of the pacemaker to place the pacing electrode in contact with the tissue. In some embodiments, the fixation mechanism can comprise a plurality of hooks or protrusions positioned near a distal portion of the pacemaker. The fixation mechanism(s) can be configured to penetrate the endocardium of the patient and reside mostly within the myocardium. Methods of delivering the leadless cardiac pacemaker into the heart are also provided.

Claims

1. A leadless cardiac pacemaker, comprising:

a hermetic housing;

a pacing electrode disposed on a distal portion of the housing;

an electronics package disposed in the housing, the electronics package configured to generate and deliver pacing signals to the pacing electrode; and

a fixation mechanism separate from the pacing electrode and disposed on the distal portion of the housing, the fixation mechanism having a diameter less than or equal to an outer diameter of the hermetic housing and comprising less than two turns of rotation from a distal end of the fixation mechanism to a proximal end of the fixation mechanism.

2. The pacemaker of claim 1 wherein the fixation mechanism comprises less than one and a half turns of rotation from the distal end of the fixation mechanism to the proximal end of the fixation mechanism.

3. The pacemaker of claim 1 wherein the fixation mechanism comprises less than one and a quarter turns of rotation from the distal end of the fixation mechanism to the proximal end of the fixation mechanism.

4. The pacemaker of claim 1 wherein the pacing electrode comprises a dome shape.

5. The pacemaker of claim 1 wherein the pacing electrode is attached to the housing via a compliant spring to reduce compression force against the heart tissue.

6. The pacemaker of claim 1 wherein the pacing electrode is attached to the housing via a silicon adhesive to reduce compression force against the heart tissue.

7. The pacemaker of claim 1 wherein the fixation mechanism comprises a helix.

8. The pacemaker of claim 7 wherein the helix rotates less than or equal to 450 degrees.

9. The pacemaker of claim 7 wherein the helix at least partially surrounds the pacing electrode.

10. The pacemaker of claim 1 wherein the fixation mechanism comprises a constant diameter.

11. The pacemaker of claim 1 wherein the fixation mechanism has a diameter between 2.5 mm and 5 mm.

12. The pacemaker of claim 1 wherein the fixation mechanism comprises a longitudinal length of less than 1.8 mm.

13. The pacemaker of claim 1 wherein the distal portion of the housing has an outer diameter less than an outer diameter of the hermetic housing.

14. The pacemaker of claim 1 wherein the fixation mechanism is sized and configured so that it does not perforate a myocardium of a patient when fully screwed into cardiac tissue.

15. The pacemaker of claim 1 wherein the fixation mechanism comprises a radial portion substantially aligned with a circumference of the housing and a connecting portion attaching the fixation mechanism to the housing.

16. The pacemaker of claim 15 wherein the radial portion is substantially perpendicular to the connecting portion.

17. The pacemaker of claim 15 wherein the connecting portion has a length smaller than a thickness of a myocardium layer of a heart of a patient.

18. The pacemaker of claim 15 wherein the connecting portion has a length less than or equal to 1.8 mm.

19. The pacemaker of claim 15 wherein the radial portion of the fixation mechanism is configured to reside within a myocardium layer of a heart of a patient and substantially in contact with an endocardium layer of the heart of the patient.

20. The pacemaker of claim 15 further comprising a barb disposed on an interior surface of the radial portion of the fixation mechanism.

21. The pacemaker of claim 1 being further configured to receive during retrieval a protective sheath having an inner diameter similar to the outer diameter of the hermetic housing.

22. A method of affixing a pacemaker to tissue in the heart of a patient, comprising:

positioning a fixation mechanism of the pacemaker adjacent to an endocardium of the heart, the fixation mechanism having a diameter less than or equal to an outer diameter of the pacemaker;

piercing the endocardium with the fixation mechanism; and

rotating the fixation mechanism less than one and a quarter turns to insert substantially all of the fixation mechanism into the myocardium of the heart and place a pacing electrode of the pacemaker into contact with heart tissue.

23. The method of claim 22 wherein the fixation mechanism comprises a helix.

24. The method of claim 22 wherein the pacemaker comprises a leadless cardiac pacemaker.

25. The method of claim 22 further comprising covering the pacemaker and fixation mechanism with a protective sheath and removing the pacemaker from the patient.