Techniques for modifying breathing rate using cardiac pacing

1. A method comprising:

controlling a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient;

detecting inhalation and exhalation of the patient;

determining that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increasing the pacing rate while exhalation of the patient is detected; and

incrementally decreasing the pacing rate while inhalation of the patient is detected.

2. A device comprising:

one or more electrodes configured for implantation in a patient;

a stimulation module configured to generate stimulation for delivery to the one or more electrodes; and

a processing module configured to:

control a pacing rate delivered to the one or more electrodes to control a heart rate of the patient;

detect inhalation and exhalation of the patient;

determine that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increase the pacing rate while exhalation of the patient is detected; and

incrementally decrease the pacing rate while inhalation of the patient is detected.

3. A system comprising:

means for controlling a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient;

means for detecting inhalation and exhalation of the patient;

means for determining that the patient is in a resting state; and

in response to determining that the patient is in the resting state, means for:

incrementally increasing the pacing rate while exhalation of the patient is detected; and

incrementally decreasing the pacing rate while inhalation of the patient is detected.

4. A non-transitory computer-readable storage medium comprising instructions that cause a programmable processor to:

control a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient;

detect inhalation and exhalation of the patient;

determine that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increase the pacing rate while exhalation of the patient is detected; and

incrementally decrease the pacing rate while inhalation of the patient is detected.

5. A method comprising:

controlling a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient by delivering pacing pulses during both inhalation and exhalation of the patient;

detecting inhalation and exhalation of the patient;

determining that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increasing the pacing rate while exhalation of the patient is detected; and

incrementally decreasing the pacing rate while inhalation of the patient is detected.

6. The method of claim 5 , further comprising determining that the patient is in the resting state when the heart rate of the patient has been less than a threshold heart rate for a predetermined period of time.

7. The method of claim 5 , further comprising incrementally decreasing the pacing rate to a value that is less than 75% of the threshold heart rate.

8. The method of claim 5 , further comprising determining that the patient is in the resting state based on at least one of a sensed activity level of the patient and a posture of the patient.

9. The method of claim 5 , wherein detecting inhalation and exhalation of the patient comprises:

measuring an impedance between electrodes of the IMD; and

detecting inhalation and exhalation of the patient based on the measured impedance.

10. The method of claim 9 , further comprising:

detecting inhalation of the patient based on an increase in the measured impedance; and

detecting exhalation of the patient based on a decrease in the measured impedance.

11. The method of claim 5 , further comprising determining an amount by which to incrementally increase and decrease the pacing rate based on a heart rate of the patient measured prior to incrementally increasing and decreasing the pacing rate.

12. The method of claim 5 , further comprising discontinuing incrementally increasing and decreasing the pacing rate when a breathing rate of the patient is greater than a threshold breathing rate.

13. A device comprising:

one or more electrodes configured for implantation in a patient;

a stimulation module configured to generate stimulation for delivery to the one or more electrodes; and

a processing module configured to:

control a pacing rate delivered to the one or more electrodes to control a heart rate of the patient by delivering pacing pulses during both inhalation and exhalation of the patient;

detect inhalation and exhalation of the patient;

determine that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increase the pacing rate while exhalation of the patient is detected; and

incrementally decrease the pacing rate while inhalation of the patient is detected.

14. The device of claim 13 , wherein the processing module determines that the patient is in the resting state when the heart rate of the patient has been less than a threshold heart rate for a predetermined period of time.

15. The device of claim 14 , wherein the processing module incrementally decreases the pacing rate to a value that is less than 75% of the threshold heart rate.

16. The device of claim 13 , wherein the processing module determines that the patient is in the resting state based on at least one of a sensed activity level of the patient and a posture of the patient.

17. The device of claim 13 , wherein the processing module:

measures an impedance between the one or more electrodes; and

detects inhalation and exhalation of the patient based on the measured impedance.

18. The device of claim 17 , wherein the processing module:

detects inhalation of the patient based on an increase in the measured impedance; and

detects exhalation of the patient based on a decrease in the measured impedance.

19. The device of claim 13 , wherein the processing module determines an amount by which to incrementally increase and decrease the pacing rate based on a heart rate of the patient measured prior to incrementally increasing and decreasing the pacing rate.

20. The device of claim 13 , wherein the processing module discontinues incrementally increasing and decreasing the pacing rate when a breathing rate of the patient is greater than a threshold breathing rate.

21. A system comprising:

means for controlling a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient by delivering pacing pulses during both inhalation and exhalation of the patient;

means for detecting inhalation and exhalation of the patient;

means for determining that the patient is in a resting state; and

in response to determining that the patient is in the resting state, means for:

incrementally increasing the pacing rate while exhalation of the patient is detected; and

incrementally decreasing the pacing rate while inhalation of the patient is detected.

22. The system of claim 21 , further comprising means for determining that the patient is in the resting state when the heart rate of the patient has been less than a threshold heart rate for a predetermined period of time.

23. The system of claim 21 , wherein means for detecting inhalation and exhalation of the patient comprises means for:

measuring an impedance between electrodes of the IMD; and

detecting inhalation and exhalation of the patient based on the measured impedance.

24. The system of claim 21 , further comprising means for determining an amount by which to incrementally increase and decrease the pacing rate based on a heart rate of the patient measured prior to incrementally increasing and decreasing the pacing rate.

25. The system of claim 21 , further comprising means for discontinuing incrementally increasing and decreasing the pacing rate when a breathing rate of the patient is greater than a threshold breathing rate.

26. A non-transitory computer-readable storage medium comprising instructions that cause a programmable processor to:

control a cardiac pacing rate of an implantable medical device (IMD) to control a heart rate of a patient by delivering pacing pulses during both inhalation and exhalation of the patient;

detect inhalation and exhalation of the patient;

determine that the patient is in a resting state; and

in response to determining that the patient is in the resting state:

incrementally increase the pacing rate while exhalation of the patient is detected; and

incrementally decrease the pacing rate while inhalation of the patient is detected.

27. The computer-readable storage medium of claim 26 , further comprising instructions that cause the programmable processor to determine that the patient is in the resting state when the heart rate of the patient has been less than a threshold heart rate for a predetermined period of time.

28. The computer-readable storage medium of claim 26 , wherein the instructions that cause the programmable processor to detect inhalation and exhalation of the patient comprises instructions that cause the programmable processor to:

measure an impedance between electrodes of the IMD; and

detect inhalation and exhalation of the patient based on the measured impedance.

29. The computer-readable storage medium of claim 26 , further comprising instructions that cause the programmable processor to determine an amount by which to incrementally increase and decrease the pacing rate based on a heart rate of the patient measured prior to incrementally increasing and decreasing the pacing rate.

30. The computer-readable storage medium of claim 26 , further comprising instructions that cause the programmable processor to discontinue incrementally increasing and decreasing the pacing rate when a breathing rate of the patient is greater than a threshold breathing rate.