Method and apparatus for tissue protection against ischemia using remote conditioning

• US 20070150005A1
• Filed: 12/23/2005
• Published: 06/28/2007
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Sih, Haris, Baynham, Tamara, Wagner, Darrell
• Granted Patent: US 7,885,710 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

A stimulation system delivers stimulation to protect an ischemic region of a body from tissue damage caused by ischemia. The stimulation is delivered to one or more stimulation sites remote from the ischemic region to elicit a physiological effect that protects the ischemic region from the tissue damage caused by ischemia. In one embodiment, the stimulation system delivers cardioprotective stimulation to one or more stimulation sites remote from the heart to protect the heart from injuries associated with cardiac ischemic events. In another embodiment, the stimulation system delivers remote conditioning stimulation to one or more stimulation sites in or on the heart to protect a non-cardiac region from injuries associated with non-cardiac ischemic events.

Claims

1. A system for stimulating at least one stimulation site in a body having a heart, the at least one stimulation site remote from the heart, the system comprising:

at least one stimulation output device configured for delivering non-cardiac stimulation to the at least one stimulation site; and

an implantable medical device including;

a cardioprotective stimulation module coupled to the at least one stimulation output device, the cardioprotective stimulation module adapted to deliver one or more non-cardiac stimuli capable of eliciting a cardioprotective effect against cardiac ischemia; and

a cardioprotective stimulation controller coupled to the cardioprotective stimulation module, the cardioprotective stimulation controller including;

a stimulation initiator adapted to produce cardioprotective stimulation signals; and

a stimulation timer adapted to time a cardioprotective stimulation sequence in response to each of the cardioprotective stimulation signals, the cardioprotective stimulation sequence including alternating stimulation and non-stimulation periods, the stimulation periods each having a stimulation duration during which the one or more non-cardiac stimuli are delivered, the non-stimulation periods each having a non-stimulation duration during which none of the one or more non-cardiac stimuli is delivered.

2. The system of claim 1, wherein the at least one stimulation output device comprises at least one stimulation electrode, and the cardioprotective stimulation module comprises an electrical stimulation circuit adapted to deliver one or more non-cardiac electrical stimuli through the at least one stimulation electrode.

3. The system of claim 2, wherein the implantable medical device further comprises a cardiac stimulation circuit to deliver cardiac stimulation pulses to the heart.

4. The system of claim 3, wherein the implantable medical device comprises an implantable housing configured to house the cardioprotective stimulation module, the cardioprotective stimulation controller, and the cardiac stimulation circuit, and wherein the at least one electrode is incorporated onto the implantable housing.

5. The system of claim 1, wherein the cardioprotective stimulation module is adapted to deliver one or more stimuli creating a physiological stress at the at least one stimulation site.

6. The system of claim 5, further comprising at least one physiological stress sensor adapted to sense a stress-indicating signal indicative of a level of the physiological stress.

7. The system of claim 6, wherein the at least one physiological stress sensor comprises an exertion level sensor to sense an exertion level.

8. The system of claim 6, wherein the cardioprotective stimulation controller is adapted to control the delivery of the one or more stimuli creating the physiological stress using the stress-indicating signal.

9. The system of claim 1, wherein the cardioprotective stimulation module comprises a gene regulatory device to deliver a gene regulatory signal controlling a gene expression.

10. The system of claim 1, wherein the cardioprotective stimulation module comprises one or more of an electrical stimulation device to deliver one or more electrical stimuli, a mechanical stimulation device to deliver one or more mechanical stimuli, a chemical stimulation device to deliver one or more chemical stimuli, a biological stimulation device to deliver one or more biological stimuli, an optical stimulation device to deliver one or more optical stimuli, a thermal stimulation device to deliver one or more thermal stimuli, and an acoustic stimulation device to deliver one or more acoustic stimuli.

11. The system of claim 1, wherein the stimulation initiator comprises an ischemia detector to detect a cardiac ischemic event and is adapted to produce a postconditioning signal in response to a detection of the cardiac ischemic event, the postconditioning signal being one of the cardioprotective stimulation signals.

12. The system of claim 11, wherein the stimulation initiator is further adapted to produce a plurality of preconditioning signals in response to the detection of the cardiac ischemic event, the preconditioning signals each being one of the cardioprotective stimulation signals.

13. The system of claim 1, wherein the stimulation initiator comprises a stimulation command detector to detect a cardioprotective stimulation command and is adapted to produce one or more of the cardioprotective stimulation signals in response to the detection of the cardioprotective stimulation command.

14. The system of claim 13, further comprising an external system communicatively coupled to the implantable medical device, the external system adapted to transmit the cardioprotective stimulation command.

15. The system of claim 14, wherein the external system comprises:

a user interface device to receive a user command; and

an external controller to produce the cardioprotective stimulation command in response to the user command.

16. The system of claim 15, wherein the external system comprises a handheld device.

17. A method for operating an implantable medical device to stimulate at least one stimulation site in a body having a heart, the at least one stimulation site remote from the heart, the method comprising:

receiving a cardioprotective stimulation signal;

timing a cardioprotective stimulation sequence in response to the cardioprotective stimulation signal, the cardioprotective stimulation sequence including alternating stimulation and non-stimulation periods, the stimulation periods each having a stimulation duration during which one or more non-cardiac stimuli are delivered, the non-stimulation periods each having a non-stimulation duration during which no non-cardiac stimulus is delivered; and

delivering the one or more non-cardiac stimuli from the implantable medical device to the at least one stimulation site remote from the heart during each of the stimulation period, the one or more non-cardiac stimuli capable of eliciting a cardioprotective effect against cardiac ischemia.

18. The method of claim 17, wherein delivering the one or more non-cardiac stimuli comprises delivering one or more stimuli that create a physiologic stress in the at least one stimulation site remote from the heart.

19. The method of claim 18, further comprising:

sensing at least one stress-indicating signal indicative of a level of the physiologic stress; and

adjusting the delivery the one or more stimuli that create the physiologic stress using the at least one stress-indicating signal.

20. The method of claim 19, wherein sensing the at least one stress-indicating signal comprises sensing an exertion level signal.

21. The method of claim 17, wherein delivering the one or more non-cardiac stimuli comprises delivering one or more of electrical stimuli, chemical stimuli, biologic stimuli, mechanical stimuli, optical stimuli, thermal stimuli, and acoustic stimuli.

22. The method of claim 17, further comprising:

detecting a cardiac ischemic event; and

producing the cardioprotective stimulation signal in response to the detection of the cardiac ischemic event.

23. The method of claim 22, wherein producing the cardioprotective stimulation signal comprises producing a postconditioning signal in response to the detection of the cardiac ischemic event, and wherein timing the cardioprotective stimulation sequence in response to the cardioprotective stimulation signal comprises timing a postconditioning stimulation sequence in response to the postconditioning signal.

24. The method of claim 23, wherein producing the postconditioning signal in response to the detection of the cardiac ischemic event comprises producing the postconditioning signal when a post-ischemia time interval expires, the post-ischemia time interval starting when an end of the cardiac ischemic event is detected and is up to approximately 10 minutes.

25. The method of claim 23, wherein producing the cardioprotective stimulation signal further comprises producing a plurality of preconditioning signals in response to the detection of the cardiac ischemic event, and wherein timing the cardioprotective stimulation sequence in response to the cardioprotective stimulation signal comprises timing a preconditioning stimulation sequence in response to each of the preconditioning signals.

26. The method of claim 25, wherein producing the plurality of preconditioning signals comprises producing the plurality of preconditioning signals on a periodic basis using a predetermined period in a range of approximately 24 hours to 72 hours.

27. The method of claim 17, further comprising:

detecting a cardioprotective stimulation command; and

producing the cardioprotective stimulation signal in response to the detection of the cardioprotective stimulation command.

28. The method of claim 27, wherein producing the cardioprotective stimulation signal comprises producing a postconditioning signal and a plurality of preconditioning signals in response to the detection of the cardioprotective stimulation command.

29. The method of claim 27, wherein producing the cardioprotective stimulation signal comprises producing a postconditioning signal when the detected cardioprotective stimulation command is a postconditioning command and producing a preconditioning signal when the detected cardioprotective stimulation command is a preconditioning command.

30. A system for stimulating at least one stimulation site in a heart of a body having an ischemic region remote from the heart, the system comprising:

an implantable medical device including;

a cardiac electrical stimulation circuit adapted to deliver pacing pulses;

a cardiac stimulation controller coupled to the cardiac stimulation circuit, the cardiac stimulation controller adapted to initiate and time a remote conditioning stimulation sequence in response to a therapy initiation event, the remote conditioning stimulation sequence including alternating pacing and non-pacing periods, the pacing periods each having a pacing duration during which the pacing pulses are delivered at a pacing rate that is sufficiently high to elicit a physiological effect that protects the ischemic region from ischemic tissue damage by inducing cardiac ischemia, the non-pacing periods each having a non-pacing duration during which none of the pacing pulses is delivered; and

an implant telemetry circuit coupled to the cardiac stimulation controller.

31. The system of claim 30, further comprising at least one physiological stress sensor adapted to sense a stress-indicating signal indicative of a level of physiological stress.

32. The system of claim 31, wherein the at least one physiological stress sensor comprises an exertion level sensor to sense an exertion level.

33. The system of claim 31, wherein the cardiac stimulation controller is adapted to control the delivery of the pacing pulses using the stress-indicating signal.

34. The system of claim 30, further comprising an external system communicatively coupled to the implantable medical device, the external system comprising:

a user interface device to receive a user command;

an external controller to initiate the remote conditioning stimulation sequence in response to the user command; and

an external telemetry circuit coupled to the external controller.

35. The system of claim 34, wherein the external system comprises a handheld device.

36. A method for stimulating at least one stimulation site in a heart of a body having an ischemic region remote from the heart, the method comprising:

initiating a remote conditioning stimulation sequence in response to a therapy initiation event, the remote conditioning stimulation sequence including alternating pacing and non-pacing periods;

timing the alternating pacing and non-pacing periods; and

delivering cardiac pacing pulses during each of the pacing periods at a pacing rate that is sufficiently high to elicit a physiological effect that protects the ischemic region from ischemic tissue damage by inducing cardiac ischemia.

37. The method of claim 36, further comprising sensing a stress-indicating signal indicative of a level of physiological stress.

38. The method of claim 37, further comprising controlling the delivery of the pacing pulses using the stress-indicating signal.

39. The method of claim 37, wherein sensing the stress-indicating signal comprises sensing an exertion level.