Sensor guided epicardial lead

• US 20060047333A1
• Filed: 08/31/2004
• Published: 03/02/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Westlund, Randy, Tockman, Bruce A.
• Granted Patent: US 7,515,969 B2
• Time in Patent Office: Days
• US Class Current: 607/127
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium

Abstract

Implantable cardiac monitoring and stimulation methods and devices with epicardial leads having sensor feedback. A fixed or extendable/retractable sensor may be displaceable within the lead'"'"'s lumen and configured to sense the presence of an anatomical feature or physiological parameter of cardiac tissue in proximity with the lead body'"'"'s distal end. The sensor may include an ultrasonic sensing element, a perfusion sensor, a photoplethysmographic sensor, or a blood oximetry sensor. Methods of determining suitability for implanting a lead involve the steps of accessing an epicardial surface of the heart, and moving the cardiac lead to an implant site at the epicardial surface. A transmitted signal is directed at the implant site. A reflected signal is received, indicative of the presence of a blood vessel at the implant site. A determination may be made to determine whether the implant site is suitable or unsuitable based on the reflected signal.

Claims

1. A cardiac lead, comprising:

a lead body having a proximal end, a distal end, and a lumen defined between the proximal end and the distal end, the lead body comprising one or more electrical conductors;

at least one electrode configured for cardiac implantation situated at or near the distal end of the lead body and coupled to the one or more electrical conductors; and

a sensor displaceable within the lumen of the lead body and configured to sense a presence of an anatomical feature or a physiological parameter of cardiac tissue in proximity with the lead body'"'"'s distal end.

2. The lead of claim 1, wherein the electrode is extendable and retractable relative to the distal end of the lead body.

3. The lead of claim 1, wherein the sensor is displaceable beyond the distal end of the electrode.

4. The lead of claim 1, wherein the electrode comprises a fixation arrangement engagable with epicardial or myocardial tissue.

5. The lead of claim 1, wherein the electrode comprises a helical fixation arrangement.

6. The lead of claim 1, wherein the sensor comprises the electrode.

7. The lead of claim 1, wherein the sensor comprises a fixation arrangement engagable with epicardial or myocardial tissue.

8. The lead of claim 1, wherein the lead body further comprises a fixation arrangement configured to engage epicardial or myocardial tissue.

9. The lead of claim 1, wherein the electrode is configured to at least partially encircle the sensor.

10. The lead of claim 1, wherein the sensor is provided on a tissue perforating tool or device.

11. The lead of claim 1, wherein the sensor is configured to sense blood presence or blood flow in tissue.

12. The lead of claim 1, wherein the sensor comprises an ultrasonic sensing element.

13. The lead of claim 1, wherein the sensor is configured to sense tissue impedance.

14. The lead of claim 1, wherein the sensor comprises a perfusion sensor.

15. A cardiac lead system, comprising:

a lead having a proximal end, a distal end, and a lumen defined between the proximal and distal ends, the lead comprising one or more electrical conductors;

an electrode configured for epicardial implantation and coupled to the one or more electrical conductors;

a sensor apparatus comprising a sensor and configured for axial displacement within the lumen; and

control circuitry coupled to the sensor and the electrode, the control circuitry adapted to detect the presence of an anatomical feature or a physiological parameter of cardiac tissue at an implant site.

16. The lead system of claim 15, wherein the sensor is configured to sense blood presence or blood flow in tissue at the implant site.

17. The lead system of claim 15, wherein the sensor comprises a tissue impedance sensor.

18. The lead system of claim 15, wherein the control circuitry is adapted to perform a pacing threshold test.

19. The lead system of claim 15, wherein the control circuitry is adapted to perform a tissue impedance test.

20. The lead system of claim 15, wherein the sensor apparatus comprises a tissue perforating element.

21. A method of determining suitability for implanting a cardiac lead on a surface of a patient'"'"'s heart, comprising:

accessing, via a patient'"'"'s chest cavity, an epicardial surface of the heart;

moving the cardiac lead to an implant site at the epicardial surface;

stabilizing the lead at the implant site;

transmitting a signal from the lead directed at the implant site;

receiving at the lead a reflected signal resulting from the transmitted signal indicative of the presence or absence of a blood vessel at the implant site; and

determining whether the implant site is suitable or unsuitable for implantation of the cardiac lead at least in part using the reflected signal.

22. The method of claim 21, comprising:

determining a physiological parameter at the implant site; and

determining whether the implant site is suitable or unsuitable for implantation of the cardiac lead using the reflected signal and the physiological parameter.

23. The method of claim 21, further comprising generating blood-flow signals representative of blood vessel presence at or near the implant site using the reflected signal.

24. A method of determining suitability for implanting a cardiac lead on a surface of a patient'"'"'s heart, comprising:

accessing, via a patient'"'"'s chest cavity, an epicardial surface of the heart;

moving the cardiac lead to an implant site at the epicardial surface;

transmitting, from the cardiac lead, ultrasonic energy directed at the implant site;

receiving, at the cardiac lead, ultrasonic energy reflected from the implant site; and

identifying the site as suitable or unsuitable for implanting the cardiac lead at least in part using the received ultrasonic energy.

25. The method of claim 24, further comprising detecting presence or absence of blood perfusion at the implant site using the received ultrasonic energy.

26. The method of claim 24, further comprising:

detecting presence or absence of blood perfusion at the implant site using the received ultrasonic energy; and

performing a pacing threshold test at the implant site;

wherein the site is identified as suitable for lead implantation in response to detecting an absence of blood perfusion at the site and obtaining an acceptable pacing threshold for the site.

27. A system for determining suitability for implanting a cardiac lead on a surface of a patient'"'"'s heart, comprising:

means for accessing, via a patient'"'"'s chest cavity, an epicardial surface of the heart;

means for moving the cardiac lead to an implant site at the epicardial surface;

means for transmitting a signal directed at the implant site;

means for receiving a reflected signal resulting from the transmitted signal indicative of blood perfusion at the implant site;

means for determining an electrical parameter of tissue at the implant site; and

means for determining whether the implant site is suitable or unsuitable for implantation of the cardiac lead using the reflected signal and the electrical parameter.

28. A system for determining suitability for implanting a cardiac lead on a surface of a patient'"'"'s heart, comprising:

means for accessing, via a patient'"'"'s chest cavity, an epicardial surface of the heart;

means for moving the cardiac lead to an implant site at the epicardial surface;

means for transmitting ultrasonic energy directed at the implant site;

means for receiving ultrasonic energy reflected from the implant site; and

means for identifying the site as suitable or unsuitable for implanting the cardiac lead at least in part using the received ultrasonic energy.