METHOD AND APPARATUS FOR USING HEART RATE VARIABILITY AS A SAFETY CHECK IN ELECTRICAL THERAPIES

• US 20100131026A1
• Filed: 01/26/2010
• Published: 05/27/2010
• Est. Priority Date: 01/18/2005
• Status: Active Grant

• Current Assignee: Andrew P. Kramer, Gerrard M. Carlson, Jiang Ding, Joseph M. Pastore, Rodney W. Salo, Yinghong Yu
• Original Assignee: Andrew P. Kramer, Gerrard M. Carlson, Jiang Ding, Joseph M. Pastore, Rodney W. Salo, Yinghong Yu
• Inventors: Carlson, Gerrard M., Pastore, Joseph M., Yu, Yinghong, Ding, Jiang, Kramer, Andrew P., Salo, Rodney W.
• Granted Patent: US 8,831,724 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36592 controlled by the heart rate variability

Abstract

A cardiac rhythm management system modulates the delivery of pacing and/or autonomic neurostimulation pulses based on heart rate variability (HRV). An HRV parameter being a measure of the HRV is produced to indicate a patient'"'"'s cardiac condition, based on which the delivery of pacing and/or autonomic neurostimulation pulses is started, stopped, adjusted, or optimized. In one embodiment, the HRV parameter is used as a safety check to stop an electrical therapy when it is believed to be potentially harmful to continue the therapy.

Claims

1. A method, comprising:

sensing a cardiac signal;

measuring a variance in cardiac cycle lengths over a predetermined period of time to produce an HRV parameter based on the sensed cardiac signal;

delivering electrical stimulation pulses by executing at least a first stimulation algorithm;

stopping the execution of the first stimulation algorithm when the HRV parameter is out of a safety window; and

adjusting the safety window dynamically based on an indication, estimation, or prediction of an activity level.

2. The method of claim 1, wherein sensing the cardiac signal comprises sensing one or more one electrograms, and delivering the electrical stimulation pulses comprises delivering pacing pulses.

3. The method of claim 1, further comprising sensing one or more neural signals, and delivering the electrical stimulation pulses comprises delivering neurostimulation pulses.

4. The method of claim 1, comprising dynamically adjusting the safety window based on a heart rate.

5. The method of claim 1, wherein stopping the execution of the first stimulation algorithm when the HRV parameter is out of the safety window comprises:

comparing the HRV parameter to a first safety threshold; and

stopping the execution of the first stimulation algorithm when the HRV parameter falls below the first safety threshold.

6. The method of claim 5, wherein the first stimulation algorithm comprises a bradycardia pacing algorithm.

7. The method of claim 5, wherein the first stimulation algorithm comprises a remodeling control therapy (RCT) pacing algorithm.

8. The method of claim 5, further comprising:

comparing the HRV parameter to a second safety threshold; and

resuming the execution of the first stimulation algorithm when the HRV parameter exceeds the second safety threshold.

9. The method of claim 8, further comprising starting an execution of a second stimulation algorithm when the HRV parameter falls below the first safety threshold.

10. The method of claim 9, further comprising stopping the execution of the second stimulation algorithm when the HRV parameter exceeds the second safety threshold.

11. The method of claim 10, wherein the first stimulation algorithm is a remodeling control (RCT) pacing algorithm, and the second stimulation algorithm is a cardiac resynchronization (CRT) pacing algorithm.

12. The method of claim 10, wherein the first stimulation algorithm is a remodeling control (RCT) pacing algorithm, and the second stimulation algorithm is a bradycardia pacing algorithm.

13. The method of claim 10, wherein the first stimulation algorithm is a parasympathetic nerve stimulation algorithm, and the second therapy is a sympathetic nerve stimulation algorithm.

14. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce a parameter indicative of a balance between sympathetic and parasympathetic activities.

15. The method of claim 14, wherein measuring HRV to produce the parameter indicative of the balance between sympathetic and parasympathetic activities comprises producing a Ratio of Low Frequency HRV to High Frequency HRV ratio (LF/HF ratio).

16. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce a Standard Deviation of Normal-to-Normal intervals (SDNN).

17. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce a Standard Deviation of Averages of Normal-to-Normal intervals (SDANN).

18. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce a Ratio of Low Frequency HRV to High Frequency HRV ratio (LF/HF ratio).

19. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce an HRV footprint.

20. The method of claim 1, wherein measuring HRV to produce the HRV parameter comprises measuring HRV to produce and a Root-Mean-Square of Successive Differences (RMSSD).