Cardiac lead

• US 5,255,693 A
• Filed: 06/10/1992
• Issued: 10/26/1993
• Est. Priority Date: 11/02/1989
• Status: Expired due to Term

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Possis Medical, Inc. (Bayer AG)
• Inventors: Hill, John C., Dutcher, Robert G., Scott, Robert J.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/896,663
• Time in Patent Office: 503 Days
• Field of Search: 128/783, 128/784, 128/785, 128/786, 128/790, 128/419 P
• US Class Current: 607/120
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium

Abstract

A cardiac lead for transmitting electric current to the heart and/or sensing and monitoring electrical activity of the heart has an elongated electrical conductor connected to a head. An electrode mounted on the head comprises a helical wire adapted to be turned into heart tissue. The helical wire is coated with platinum black particles which decrease electrical losses at the electrode-tissue interface. A plug impregnated with a drug located within the head is in contact with the helical wire and platinum black particles thereon. The drug migrates from the plug to the active outer end section of the electrode.

Claims

1. A cardiac lead connectable to a cardiac management device for transmitting electric current to and/or receiving electrical signals from the myocardium of the heart comprising:

an elongated flexible conductor wire means, sheath means of non-electrical conductive material surrounding said conductor wire means, an electrical connector attached to the wire means adapted to be connected to a cardiac management device, a head of non-electrically conductive material connected to said conductor wire means and sheath means, a helical electrode having a first end section extended into said head and connected to said conductor wire means and a helical second end section extended from said head adapted to be screwed into the myocardium of a heart, said second end section having an outer helical surface terminating in a point, a layer of platinum black particles attached to substantially the entire outer helical surface of the second end section, said layer of platinum black particles having generally uniform particle size and generally uniform distribution on said outer surface of the second end section of the electrode whereby said layer has a continuous and generally uniform microporous outer platinum black surface locatable in surface contact with the myocardium of the heart whereby said layer of platinum black particles decreases electrical losses at the electrode-tissue interface, establishes intimate contact between the electrode and myocardium, and maximizes voltage applied to said myocardium and lowers stimulation thresholds and increases amplitude of sensed electrical signals from the myocardium.

2. The lead of claim 1 including:

porous means secured to the head surrounding said helical second end section to enhance fibrotic growth to connect the head and second end section to the myocardium.

3. The lead of claim 2 wherein:

the porous means is a generally circular shaped fabric secured to the head.

4. The lead of claim 1 wherein:

said layer of platinum black particles are electrochemically plated on the entire outer surface of the exposed external second section of the electrode.

5. The lead of claim 1 including:

sheath means of non-electrically conductive material extended from said head covering a portion of the helical second section of said electrode, said second section having an end portion projected from said sheath means, said end portion having an outer surface covered with said platinum black particles.

6. The lead of claim 1 including:

sheath means of non-electrical conductive material joined to the head covering a portion of the helical second section of said electrode, said helical electrode having about one half turn end portion extended from said sheath, said end portion having an outer surface covered with said platinum black particles.

7. A cardiac lead connectable to a cardiac management device for transmitting electric current to and/or receiving electrical signals from the myocardium of the heart comprising:

an elongated flexible conductor wire means, sheath means of non-electrical conductive material surrounding said conductor wire means, an electrical connector attached to the wire means adapted to be connected to a cardiac management device, a head of non-electrically conductive material connected to said conductor wire means and sheath means, a helical electrode having a first end section extended into said head and connected to said conductor wire means and a helical second end section extended from said head adapted to be screwed into the myocardium of a heart, said second end section terminating in a point, said helical electrode having an outer surface, a layer of platinum black particles attached to substantially the entire outer surface of the helical electrode, said layer of platinum black particles having substantially uniform particle size and uniform distribution on said outer surface of the electrode whereby said layer has a generally has continuous and uniform microporous outer platinum black surface locatable in surface contact with the myocardium of the heart whereby said layer of platinum black particles decreases electrical losses at the electrode-tissue interface, establishes intimate contact between the electrode and myocardium, and maximizes voltage applied to said myocardium and lowers stimulation thresholds and increases amplitude of sensed electrical signals from the myocardium and a plug impregnated with a drug mounted on the head, said first end section of the helical electrode and platinum black particles thereon being engageable with the plug to permit the drug to move from the plug to the second end section of the helical electrode.

8. The lead of claim 7 including:

porous means secured to the head surrounding said helical second end section to enhance fibrotic growth to connect the head and second end section to the myocardium.

9. The lead of claim 8 wherein:

the porous means is a generally circular shaped fabric secured to the head.

10. The lead of claim 7 including:

sheath means of non-electrically conductive material extended from said head covering a portion of the helical second section of said electrode and platinum black particles thereon, said second section having an end portion projected from said sheath means, said end portion having an outer surface covered with said platinum black particles.

11. The lead of claim 7 including:

sheath means of non-electrical conductive material joined to the head covering a portion of the helical second section of said electrode and platinum black particles thereon, said helical electrode having about one half turn end portion extended from said sheath, said end portion having an outer surface covered with said platinum black particles.

12. The lead of claim 7 wherein:

said head has a pocket, said plug being located within said pocket, said first end section of the helical electrode surrounding said plug with the platinum black particles thereon in engagement with the plug.

13. The lead of claim 12 wherein:

the pocket has a cylindrical shape, said plug having a cylindrical shape and size to fill the pocket and an axis aligned with the longitudinal axis of the helical electrode.

14. A cardiac lead connectable to a cardiac management device for transmitting electric current to and/or receiving electrical signals from the heart comprising:

an elongated flexible conductor wire means, sheath means of non-electrical conductive material surrounding said conductor wire means, an electrical connector attached to the wire means adapted to be connected to a cardiac management device, a head of non-electrically conductive material connected to said conductor wire means and sheath means, an electrode having a first end section extended into said head and connected to said conductor wire means and a second helical end section extended from said head adapted to engage heart tissue, sheath means of non-electrical conductive material extended from the head covering a portion of the helical second section of said electrode, said helical electrode having about one-half turn end portion extended from said sheath, means accommodating a drug mounted on the head, said electrode having an outer surface, means attached to the outer surface of the electrode engageable with the means accommodating a drug and the heart tissue at the second end section thereof for decreasing electrical losses at the electrode-tissue interface, maximizing voltage applied to said heart tissue, lower stimulation thresholds and increase amplitude of sensed electrical signals from the heart tissue and dispense the drug adjacent the stimulation site, said end portion having an outer surface covered with said means for decreasing electrical losses at the electrode tissue interface and dispense the drug adjacent the stimulate site.

15. The lead of claim 14 including:

porous means secured to the head surrounding said second end section to enhance fibrotic growth to connect the head and second end section to the heart tissue.

16. The lead of claim 14 wherein:

said head has a pocket, said plug being located within said pocket, said first end section of the electrode being engageable with said plug whereby drug from the plug migrates to the second end section of the electrode and dispenses to the stimulation site.

17. The lead of claim 16 wherein:

the pocket has a cylindrical shape, said plug having a cylindrical shape and size to fill the pocket.

18. The lead of claim 14 wherein:

said means attached to the outer surface of the electrode comprises platinum black particles.