Endocardial lead with lateral active fixation

• US 5,759,202 A
• Filed: 04/28/1997
• Issued: 06/02/1998
• Est. Priority Date: 04/28/1997
• Status: Expired due to Term

• Current Assignee: Intermedics Incorporated (Boston Scientific Corporation)
• Original Assignee: Sulzer Intermedics, Inc. (Sulzer AG)
• Inventors: Schroeppel, Edward A.
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US08/848,524
• Time in Patent Office: 400 Days
• Field of Search: 607/122, 607/123, 607/126, 607/127, 607/128, 607/130, 600/373-375, 600/377, 600/381
• US Class Current: 607/126
• CPC Class Codes: A61N 1/057 Anchoring means; Means for fixing the head inside the heart

Abstract

A lead assembly adapted for transvenous implantation into a human heart is provided. The lead assembly includes a connector for electrical connection to a cardiac stimulator. An elongated sheath assembly projects from the connector. The sheath assembly includes an inner elastic insulating sheath that includes a coextensive lumen for receipt of a stylet. An outer elastic insulating sheath is disposed around the inner sheath, thereby defining an elongated annular space. The outer sheath has an aperture that defines a gripping region. A biasing wire is disposed in the annular space. The biasing wire is connected to the connector proximally and is approximately coterminous at its distal end with the outer sheath. The biasing wire has a plurality of coils exposed by the aperture in the gripping region. By first stretching and then relaxing the lead assembly, the coils of the biasing wire pinch small portions of the myocardium to laterally fix the lead assembly at a given location in the heart.

Claims

1. A cardiac lead assembly having an expanded position and a retracted position, comprising:

a connector for attachment to a cardiac stimulator; and

a sheath assembly coupled to said connector, said sheath assembly comprising

a first elastic insulating sheath having a lumen defined thereby;

a first biasing wire disposed around said first sheath and coupled to said connector to provide an electrical pathway therefrom, said biasing wire having a first plurality of coils and a distal end; and

a second elastic insulating sheath disposed over and coupled to said first sheath and having an aperture exposing at least two of said first plurality of coils, said at least two of said first plurality of coils being operable to engage a portion of myocardial tissue between said at least two of said first plurality of coils when said lead assembly is moved from said expanded position to said retracted position.

2. The cardiac lead assembly of claim 1, comprising a first electrode coupled to said distal end of said biasing wire.

3. The cardiac lead assembly of claim 1, comprising a conducting wire coupled to said connector and a second electrode coupled to said conducting wire.

4. The cardiac lead assembly of claim 1, wherein each of said at least two coils has a plurality of barbs to facilitate engagement of said portion of myocardial tissue.

5. The cardiac lead assembly of claim 1, wherein each of said at least two coils has a plurality of serrations to facilitate engagement of said portion of myocardial tissue.

6. The cardiac lead assembly of claim 1, comprising:

a second biasing wire disposed around said second sheath, said second biasing wire having a second plurality of coils;

an annular member coupled to said second sheath, said annular member having a central opening disposed in said lumen and having a first diameter; and

a third elastic insulating sheath disposed over and coupled to said second sheath and having a second proximal portion and a second distal portion, said second proximal portion and said second distal portion being separated a preselected distance to expose at least two of said second plurality of coils, said at least two of said second plurality of coils being operable to engage a portion of myocardial tissue between said at least two of said second plurality of coils when a stylet having a diameter larger than said first diameter is inserted into said lumen and engages said annular member and said lead assembly is moved from said expanded position to said retracted position.

7. A cardiac lead assembly having an expanded position and a retracted position, comprising:

a connector for attachment to a cardiac stimulator; and

a sheath assembly coupled to said connector, said sheath assembly comprising;

a first elastic insulating sheath having a lumen defined thereby;

a first biasing wire disposed around said first sheath, said biasing wire having a first plurality of coils and a distal end;

a second elastic insulating sheath disposed over and coupled to said first sheath and having a first aperture exposing at least two of said first plurality of coils, said at least two of said plurality of coils being operable to engage a portion of myocardial tissue between said at least two of said plurality of coils when said lead assembly is moved from said expanded position to said retracted position;

a second biasing wire disposed around said second sheath, said second biasing wire having a second plurality of coils, said first and second biasing wires being coupled to said connector to provide electrical pathways therefrom;

an annular member coupled to said second sheath, said annular member having a central opening disposed in said lumen and having a first diameter; and

a third elastic insulating sheath disposed over and coupled to said second sheath and having a second aperture exposing at least two of said second plurality of coils, said at least two of said second plurality of coils being operable to engage a portion of myocardial tissue between said at least two of said second plurality of coils when a stylet having a diameter larger than said first diameter is inserted into said lumen and engages said annular member and said lead assembly is moved from said expanded position to said retracted position.

8. The cardiac lead assembly of claim 7, comprising a first electrode coupled to said distal end of said first biasing wire.

9. The cardiac lead assembly of claim 7, comprising a conducting wire coupled to said connector and a second electrode coupled to said conducting wire.

10. The cardiac lead assembly of claim 7, wherein each of said at least two of said first and said second plurality of coils has a plurality of barbs to facilitate engagement of said portion of myocardial tissue.

11. The cardiac lead assembly of claim 7, wherein each of said at least two of said first and said second plurality of coils has a plurality of serrations to facilitate engagement of said portion of myocardial tissue.

12. A cardiac stimulation system, comprising:

a cardiac stimulator; and

a cardiac lead assembly coupled to said cardiac stimulator, said cardiac lead assembly comprising;

a connector attached to said stimulator;

a first elastic insulating sheath coupled to said connector;

a biasing wire disposed around said first sheath and coupled to said connector to provide an electrical pathway therefrom, said biasing wire having a plurality of coils and a distal end; and

a second elastic insulating sheath disposed over said first sheath and having a first aperture exposing at least two of said coils, said at least two coils being operable to engage a portion of myocardial tissue between said at least two coils when said lead assembly is moved from an expanded position to a retracted position.

13. The cardiac lead assembly of claim 12, comprising a first electrode coupled to said distal end of said biasing wire.

14. The cardiac lead assembly of claim 12, comprising a conducting wire coupled to said connector and a second electrode coupled to said conducting wire.

15. The cardiac lead assembly of claim 12, wherein each of said at least two coils has a plurality of barbs to facilitate engagement of said portion of myocardial tissue.

16. The cardiac lead assembly of claim 12, wherein each of said at least two coils has a plurality of serrations to facilitate engagement of said portion of myocardial tissue.

17. The cardiac stimulation system of claim 12, comprising:

a second biasing wire disposed around said second sheath, said second biasing wire having a second plurality of coils and being coupled to said connector to provide an electrical pathway therefrom;

an annular member coupled to said second sheath, said annular member having a central opening disposed in said lumen and having a first diameter; and

a third elastic insulating sheath disposed over and coupled to said second sheath and having a second aperture exposing at least two of said second plurality of coils, said at least two of said second plurality of coils being operable to engage a portion of myocardial tissue between said at least two of said second plurality of coils when a stylet having a diameter larger than said first diameter is inserted into said lumen and engages said annular member and said lead assembly is moved from said expanded position to said retracted position.