METHOD AND APPARATUS FOR SHORT-TERM HEART RATE VARIABILITY MONITORING AND DIAGNOSTICS

• US 20080306564A1
• Filed: 06/11/2007
• Published: 12/11/2008
• Est. Priority Date: 06/11/2007
• Status: Abandoned Application

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Wei, Xuan, Carlson, Gerrard M., Arcot-Krishnamurthy, Shantha
• Application Number:
  US11/761,107
• Publication Number:
  US 20080306564A1
• Time in Patent Office: Days
• US Class Current: 607/18
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A diagnostic system monitors autonomic using short term heart rate variability (STHRV). Some examples apply a therapy that is adjusted based on wellness indicator. A wellness indicator is a measure of the STHRV produced to indicate a patient'"'"'s cardiac condition.

Claims

1. A cardiac rhythm management system, comprising:

a sensing circuit configured to sense a cardiac signal;

a short term heart rate variability (STHRV) measurement circuit, coupled to the sensing circuit, configured to characterize the cardiac signal to measure at least a first STHRV measurement during a period of time compatible with an outpatient procedure and to provide at least a first wellness indicator based on the first STHRV measurement; and

a wellness circuit configured to compute a first wellness indicator using the first STHRV measurement.

2. The system of claim 1, comprising:

a communications circuit coupled to the wellness circuit; and

a programmer configured to communicate with the communications circuit and to display the wellness indicator.

3. The system of claim 1, wherein the sensing circuit comprises a circadian rhythm measurement circuit to associate the first wellness indicator with a circadian rhythm parameter.

4. The system of claim 1, wherein the STHRV measurement circuit comprises one or more of a Standard Deviation of Normal-to-Normal intervals (SDNN) circuit to provide an SDNN characterizing the STHRV measurement, a Standard Deviation of Averages of Normal-to-Normal intervals (SDANN) circuit to provide an SDANN characterizing the STHRV measurement, a Ratio of Low Frequency STHRV to High Frequency STHRV ratio (LF/HF ratio) circuit to provide an LF/HF ratio characterizing the STHRV measurement, an STHRV footprint circuit to provide an STHRV footprint characterizing the STHRV measurement, and a Root-Mean-Square of Successive Differences (RMSSD) circuit to provide an RMSSD characterizing the STHRV measurement.

5. The system of claim 1, comprising:

a pulse output circuit configured to deliver electrical stimulation pulses; and

a stimulation control circuit coupled to the sensing circuit, the STHRV measurement circuit, and the pulse output circuit, the stimulation control circuit being configured to control delivery of one or more electrical stimulation pulses based on at least the first wellness indicator.

6. The system of claim 5, wherein the stimulation control circuit is configured to control delivery of cardiac resynchronization therapy (CRT) pacing.

7. The system of claim 5, wherein the stimulation control circuit includes a feedback circuit configured to adjust delivery of the one or more electrical stimulation pulses based on the first wellness indicator and at least a second wellness indicator.

8. The system of claim 1, wherein the period of time is approximately 5 minutes.

9. The system of claim 8, wherein the period of time is approximately 2 minutes.

10. A method, comprising:

sensing a cardiac signal; and

measuring STHRV to provide at least a first wellness indicator based on a first STHRV measured during a time period compatible with an outpatient procedure.

11. The method of claim 10, comprising:

storing the first STHRV; and

comparing the first STHRV to a threshold STHRV to determine the first wellness indicator.

12. The method of claim 10, wherein measuring STHRV to provide the wellness indicator comprises measuring STHRV to provide an autonomic balance parameter indicative of a balance between sympathetic and parasympathetic activities.

13. The method of claim 10, comprising detecting sleep apnea by measuring a first respiratory parameter and a second respiratory parameter and associating the first respiratory parameter with the first wellness indicator and a the second respiratory parameter with a second wellness indicator.

14. The method of claim 10, comprising measuring a first posture and a second posture, and associating the first postures with the first wellness indicator, and the second posture with a second wellness indicator.

15. The method of claim 10, comprising measuring a second STHRV to provide a second wellness indicator and trending the first wellness indicator and the second wellness indicator to provide an STHRV wellness trend.

16. The method of claim 15, comprising measuring the first STHRV and the second STHRV under substantially similar conditions;

and indicating a potential heart failure condition when the STHRV wellness trend demonstrates a decrease in STHRV over time.

17. The method of claim 16, comprising measuring a third STHRV to provide a third wellness indicator and providing an indication of a potential myocardial infarction when the first and third wellness indicators are substantially similar, while the second wellness indicator, that is measured between the first and third wellness indicators, demonstrates a wellness indicator that is less than the first and third wellness indicators.

18. The method of claim 10, comprising:

detecting a first activity level and associating the first activity level with the first wellness indicator;

detecting a second activity level and associating the second activity level with a second wellness indicator; and

detecting a decrease in wellness when the second wellness indicator is less than the first wellness indicator.

19. The method of claim 18, comprising providing an activity adjustment indicator when a decrease in wellness is detected.

20. The method of claim 10, comprising providing electrical stimulation pulses based at least on the first wellness indicator.

21. The method of claim 20, comprising:

associating a first electrical stimulation therapy with the first wellness indicator;

measuring a second STHRV to provide a second wellness indicator;

associating a second electrical stimulation therapy with the second wellness indicator;

trending the first wellness indicator and the second wellness indicator to provide an STHRV wellness trend;

determining an improved electrical stimulation based on the STHRV wellness trend; and

providing the improved electrical stimulation therapy.

22. The method of claim 20, comprising:

sensing a neural signal;

associating the first wellness indicator with the neural signal; and

delivering neurostimulation therapy based on the association of the first wellness indicator with the neural signal.

23. A system, comprising:

an implantable case including at least a first lead, the first lead having at least a first electrode;

means for sensing a cardiac signal, the means for sensing a cardiac signal being disposed in the implantable case and being in electrical connection with at least the first electrode;

means for measuring STHRV to provide at least one wellness indicator based on a cardiac signal measured during an outpatient procedure; and

means for indicating wellness based on associating at least the first wellness indicator with at least a first wellness state.

24. The system of claim 23, wherein the means for sensing the cardiac signal include a sensing circuit configured to sense a cardiac signal.

25. The system of claim 24, wherein the means for measuring STHRV to provide at least one wellness indicator based on the cardiac signal during an outpatient procedure include a short term heart rate variability (STHRV) measurement circuit, coupled to the sensing circuit, and configured to characterize the cardiac signal to measure at least a first STHRV measurement during a period of time compatible with an outpatient clinical visit and to provide at least a first wellness indicator based on the first STHRV measurement.