METHOD AND APPARATUS FOR TISSUE PROTECTION AGAINST ISCHEMIA USING REMOTE CONDITIONING

• US 20110077701A1
• Filed: 12/08/2010
• Published: 03/31/2011
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Darrell O. Wagner, Haris J. Sih, Tamara Colette Baynham
• Original Assignee: Darrell O. Wagner, Haris J. Sih, Tamara Colette Baynham
• Inventors: Wagner, Darrell O., Baynham, Tamara Colette, Sih, Haris J.
• Granted Patent: US 8,874,207 B2
• Time in Patent Office: Days
• US Class Current: 607/3
• 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 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.

2. The method of claim 1, 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.

3. The method of claim 2, 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.

4. The method of claim 3, wherein sensing the at least one stress-indicating signal comprises sensing an exertion level signal.

5. The method of claim 1, 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.

6. The method of claim 1, further comprising:

detecting a cardiac ischemic event; and

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

7. The method of claim 6, 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.

8. The method of claim 7, 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.

9. The method of claim 7, 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.

10. The method of claim 9, 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.

11. The method of claim 1, further comprising:

detecting a cardioprotective stimulation command; and

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

12. The method of claim 11, 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.

13. The method of claim 11, 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.

14. 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.

15. The system of claim 14, further comprising at least one physiological stress sensor adapted to sense a stress-indicating signal indicative of a level of physiological stress.

16. The system of claim 15, wherein the at least one physiological stress sensor comprises an exertion level sensor to sense an exertion level.

17. The system of claim 15, wherein the cardiac stimulation controller is adapted to control the delivery of the pacing pulses using the stress-indicating signal.

18. The system of claim 14, 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.

19. The system of claim 18, wherein the external system comprises a handheld device.

20. 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.

21. The method of claim 20, further comprising sensing a stress-indicating signal indicative of a level of physiological stress.

22. The method of claim 21, further comprising controlling the delivery of the pacing pulses using the stress-indicating signal.

23. The method of claim 21, wherein sensing the stress-indicating signal comprises sensing an exertion level.