SENSING INTEGRITY DETERMINATION BASED ON CARDIOVASCULAR PRESSURE

• US 20090299429A1
• Filed: 07/25/2008
• Published: 12/03/2009
• Est. Priority Date: 06/02/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Mayotte, Mark J.
• Granted Patent: US 8,126,553 B2
• Time in Patent Office: Days
• US Class Current: 607/18
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371

Abstract

Electrical noise may be discriminated from sensed heart signals based on cardiovascular pressure. A plurality of detected cardiovascular pressure values are respectively associated with a plurality of detected tachyarrhythmia events. In some examples, a variance in the cardiovascular pressure, e.g., above a threshold range, may indicate that the detected tachyarrhythmia events are at least partially attributable to electrical noise. In some examples, stimulation therapy to a heart of a patient may be controlled based on the detection of a tachyarrhythmia episode and a variability in the cardiovascular pressure values that are associated with the tachyarrhythmia episode. In other examples, a sensing integrity indication may be generated upon determining that a tachyarrhythmia episode was associated with a variable cardiovascular pressure.

Claims

1. A method comprising:

detecting a tachyarrhythmia episode of a heart of a patient, wherein the tachyarrhythmia episode comprises a plurality of detected tachyarrhythmia events;

analyzing a plurality of cardiovascular pressure values, each of the pressure values associated with a respective one of the tachyarrhythmia events; and

generating an indication based on the analysis of the plurality of pressure values.

2. The method of claim 1, further comprising controlling therapy delivery to the patient in response to the detected tachyarrhythmia episode based on the analysis of the plurality of pressure values.

3. The method of claim 2, wherein controlling therapy delivery comprises controlling a medical device to deliver therapy to the patient based on the analysis.

4. The method of claim 2, wherein controlling therapy delivery comprises controlling a medical device to withhold therapy delivery to the patient based on the analysis.

5. The method of claim 1, wherein generating the indication comprises generating a patient or clinician alert.

6. The method of claim 1, wherein the tachyarrhythmia episode comprises at least one of a ventricular fibrillation episode, a ventricular tachycardia episode, a fast ventricular tachycardia episode or a non-sustained tachyarrhythmia episode.

7. The method of claim 1, wherein the each of the pressure values comprises at least one or more of a pulse pressure value, an average pressure value, a systolic pressure value or a diastolic pressure value.

8. The method of claim 1, wherein analyzing the plurality of cardiovascular pressure values comprises determining a variability in the plurality of cardiovascular pressure values.

9. The method of claim 8, wherein the plurality of detected tachyarrhythmia events comprises a first detected tachyarrhythmia event and a second detected tachyarrhythmia event, and determining the variability of the plurality of cardiovascular pressure values comprises determining whether a first pressure value associated with the first detected tachyarrhythmia event and a second pressure value associated with the second detected tachyarrhythmia event are within a threshold range.

10. The method of claim 8, wherein determining the variability in the plurality of cardiovascular pressure values comprises determining whether the pressure associated with at least one detected tachyarrhythmia event of the plurality of detected tachyarrhythmia events varies by a threshold percentage compared to an average pressure of at least two other detected tachyarrhythmia events of the plurality of detected tachyarrhythmia events.

11. The method of claim 10, wherein the threshold range comprises a percentage of about five percent to about twenty-five percent.

12. The method of claim 8, wherein determining the variability in the plurality of cardiovascular pressure values comprises determining whether a mean or median value of the pressure values is within a threshold range.

13. The method of claim 8, wherein determining the variability in the plurality of cardiovascular pressure values comprises determining an absolute difference between each of the pressure values and a mean value or median value of the pressure values and comparing the absolute difference to a threshold value or a threshold range.

14. The method of claim 8, wherein determining the variability in the plurality of cardiovascular pressure values comprises:

determining an absolute difference between each of the pressure values and a first mean value or a first median value of the pressure values;

determining a second mean value or a second median value of the absolute difference between each of the pressure values and the first mean value or the first median value; and

determining whether the second mean value or the second median value is within a threshold range.

15. The method of claim 14, wherein the threshold range comprises a percentage of about five percent to about twenty-five percent of the first mean value or the first median value.

16. The method of claim 1, further comprising determining whether any of the plurality of detected tachyarrhythmia events comprise a short interval, generating a count of a number of the detected tachyarrhythmia events that comprise the short interval, and analyzing the plurality of cardiovascular pressure values if the count is greater than or equal to a threshold value.

17. The method of claim 1, further comprising comparing the plurality of cardiovascular pressure values to a first threshold pressure value, generating a count of a number of cardiovascular pressure values that are less than or equal to the first threshold pressure value, and analyzing the plurality of cardiovascular pressure values if the count is greater than or equal to a second threshold value.

18. A system comprising:

a pressure sensor that monitors a pressure within a heart of a patient; and

a processor that detects a tachyarrhythmia episode of the heart, wherein the tachyarrhythmia episode comprises a plurality of tachyarrhythmia events, analyzes a plurality of cardiovascular pressure values, each of the pressure values associated with a respective one of the tachyarrhythmia events, and generates an indication based on the analysis of the plurality of pressure values.

19. The system of claim 18, wherein the processor controls therapy delivery to the patient in response to the detected tachyarrhythmia episode based on the analysis of the plurality of pressure values.

20. The system of claim 18, wherein the processor controls a medical device to withhold therapy delivery to the patient based on the analysis of the plurality of pressure values.

21. The system of claim 18, wherein the processor analyzes the plurality of plurality of cardiovascular pressure values by at least determining a variability in the plurality of cardiovascular pressure values.

22. The system of claim 21, wherein the plurality of detected tachyarrhythmia events comprises a first detected tachyarrhythmia event and a second detected tachyarrhythmia event, and the processor determines the variability in the plurality of cardiovascular pressure values by at least determining whether a first pressure value associated with the first detected tachyarrhythmia event and a second pressure value associated with the second detected tachyarrhythmia event are within a threshold range.

23. The system of claim 21, the processor determines the variability in the plurality of cardiovascular pressure values by at least determining whether the pressure associated with at least one detected tachyarrhythmia event of the plurality of detected tachyarrhythmia events varies by a threshold percentage compared to an average pressure of at least two other detected tachyarrhythmia events of the plurality of detected tachyarrhythmia events.

24. The system of claim 21, the processor determines the variability in the plurality of cardiovascular pressure values by at least determining whether a mean or median value of the pressure values is within a threshold range.

25. The system of claim 21, the processor determines the variability in the plurality of cardiovascular pressure values by at least determining an absolute difference between each of the pressure values and a mean value or median value of the pressure values and comparing the absolute difference to a threshold value or a threshold range.

26. The system of claim 21, wherein the processor determines the variability in the plurality of cardiovascular pressure values by at least:

determining an absolute difference between each of the pressure values and a first mean value or a first median value of the pressure values;

determining a second mean value or a second median value of the absolute difference between each of the pressure values and the first mean value or the first median value; and

determining whether the second mean value or the second median value is within a threshold percentage of the first mean value or the first median value, respectively.

27. The system of claim 18, wherein the processor determines whether any of the plurality of detected tachyarrhythmia events comprise a short interval and generates a count of a number of the detected tachyarrhythmia events that comprise the short interval, and wherein the processor determines the variability in the pressure within the heart if the count is greater than or equal to a threshold value.

28. The system of claim 18, wherein the processor compares the plurality of cardiovascular pressure values to a first threshold pressure value, generates a count of a number of cardiovascular pressure values that are less than or equal to the first threshold pressure value, and analyzes the plurality of cardiovascular pressure values if the count is greater than or equal to a second threshold value.

29. The system of claim 18, further comprising a sensing module that generates a signal indicative of electrical activity within the heart, wherein the processor detects the tachyarrhythmia episode based on the signal generated by the sensing module.

30. The system of claim 18, wherein the pressure values each comprises at least one or more of a pulse pressure value, an average pressure value, a systolic pressure value or a diastolic pressure value.

31. The system of claim 18, wherein the tachyarrhythmia episode comprises at least one of a ventricular fibrillation episode, a ventricular tachycardia episode, a fast ventricular tachycardia episode or a non-sustained tachyarrhythmia episode.

32. A system comprising:

means for detecting a tachyarrhythmia episode of a heart of a patient, wherein the tachyarrhythmia episode comprises a plurality of detected tachyarrhythmia events;

means for analyzing a plurality of cardiovascular pressure values, each of the pressure values associated with a respective one of the tachyarrhythmia events; and

means for generating an indication based on the analysis of the plurality of pressure values.

33. A computer-readable medium comprising instructions that cause a programmable processor to:

detect a tachyarrhythmia episode of a heart of a patient, wherein the tachyarrhythmia episode comprises a plurality of detected tachyarrhythmia events;

analyze a plurality of cardiovascular pressure values, each of the pressure values associated with a respective one of the tachyarrhythmia events; and

generate an indication based on the analysis of the plurality of pressure values.