Method and apparatus diagnosis and treatment of arrhythias

• US 6,567,691 B1
• Filed: 03/22/2000
• Issued: 05/20/2003
• Est. Priority Date: 03/22/2000
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stadler, Robert W.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/532,478
• Time in Patent Office: 1,154 Days
• Field of Search: 607/5, 607/14, 607/4, 600/515, 600/518, 600/509, 600/510
• US Class Current: 600/515
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions

Abstract

Adaptive rules for a more accurate sinus tachycardia detection mechanism for implantable device (IMD) and other devices. In an embodiment, the rule is incorporated into a prioritized, rule-based arrhythmia classification system in an IMD. If the rule is met, anti-tachyarrhythmia therapy is withheld even if a lower priority rule determines presence of a treatable tachyarrhythmia. The rule includes adaptive onset criterion, where an expected range of R—R is calculated based on a trimmed mean and a metric of R—R variability derived over a preceding series of R—R intervals. Pattern codes indicative of gradual rate changes and normal sinus rhythm will be within a grammar defined by a continuous recognition machine and will if they persist, result in the ST rule being met. All other codes inconsistent with sinus tachycardia will not adhere to the associatd grammar and will result in the ST rule not being met.

Claims

1. A method of identifying sinus rhythm in a patient'"'"'s heart, comprising:

measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

deriving an average value based upon preceding measured intervals between depolarizations of the single chamber;

determining a variability value based upon preceding measured intervals between depolarizations of the single chamber;

defining a first expected range of future measured intervals between depolarizations of the single chamber based upon the average value and the variability value; and

responsive to future measured intervals between depolarizations of the single chamber falling within the first expected range, determining that the patient is in a sinus rhythm.

2. The method of claim 1 wherein deriving the average value comprises deriving a mean value of preceding intervals between depolarizations of the single chamber.

3. The method of claim 2 wherein deriving the mean value comprises deriving a trimmed mean value of preceding intervals between depolarizations of the single chamber.

4. The method of claim 1 or claim 2 or claim 3 above, wherein measuring intervals between depolarizations of the single chamber comprises measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

5. The method of claim 4, further comprising:

measuring intervals between depolarizations of two chambers of the patient'"'"'s heart;

defining a second expected range of future measured intervals between depolarizations of the two chambers; and

responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, determining that the patient is in a sinus rhythm.

6. The method of claim 4, further comprising:

determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, determining that the patient is in a sinus rhythm.

7. The method of claim 1, further comprising:

measuring intervals between depolarizations of two chambers of the patient'"'"'s heart;

defining a second expected range of future measured intervals between depolarizations of the two chambers; and

responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, determining that the patient is in a sinus rhythm.

8. The method of claim 1, further comprising:

determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, determining that the patient is in a sinus rhythm.

9. A method of identifying sinus rhythm in a patient'"'"'s heart, comprising:

measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

based upon the measured intervals, defining a first expected range of future measured intervals between depolarizations of the single chamber;

determining whether the patient is in a 1;

1 rhythm; and

responsive to future measured intervals between depolarizations of the single chamber falling within the first expected range while the patient is in a 1;

1 rhythm, determining that the patient is in a sinus rhythm.

10. The method of claim 9 wherein defining the first expected range comprises deriving an average value of preceding intervals between depolarizations of the single chamber and defining the first expected range based upon the average value.

11. The method of claim 10 wherein deriving the average value comprises deriving a mean value of preceding intervals between depolarizations of the single chamber.

12. The method of claim 10 or claim 11, wherein defining the first expected range further comprises deriving a value of the variability of preceding measured intervals between depolarizations of the single chamber and defining the first expected range based upon the average value and the variability value.

13. The method of claim 9 or claim 10 or claim 11, wherein measuring intervals between depolarizations of the single chamber comprises measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

14. The method of claim 13, further comprising:

measuring intervals between two chambers of the patient'"'"'s heart;

defining a second expected range of future measured intervals between depolarizations of the two chambers; and

responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, determining that the patient is in a sinus rhythm.

15. The method of claim 9, further comprising:

measuring intervals between two chambers of the patient'"'"'s heart;

defining a second expected range of future measured intervals between depolarizations of the two chambers; and

responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, determining that the patient is in a sinus rhythm.

16. A method of identifying sinus rhythm in a patient'"'"'s heart, comprising:

measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

measuring intervals between two chambers of the patient'"'"'s heart;

defining a first expected range of future measured intervals between depolarizations of the single chamber of a patient'"'"'s heart;

defining a second expected range of future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart; and

responsive to future measured intervals between depolarizations of the single chamber of a patient'"'"'s heart falling within the first expected range and to future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart falling within the second expected range, determining that the patient is in a sinus rhythm.

17. The method of claim 16 wherein defining the first expected range comprises deriving an average value of preceding intervals between depolarizations of the single chamber and defining the first expected range based upon the average value.

18. The method of claim 17 wherein deriving the average value comprises deriving a mean value of preceding intervals between depolarizations of the single chamber.

19. The method of claim 17 or claim 18, wherein defining the first expected range further comprises deriving a value of the variability of preceding measured intervals between depolarizations of the single chamber and defining the first expected range based upon the average value and the variability value.

20. The method of claim 16 or claim 17 or claim 18, wherein measuring intervals between depolarizations of the single chamber of the patient'"'"'s heart comprises measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

21. The method of claim 16 wherein defining the second expected range comprises deriving an average value of preceding intervals between depolarizations of the two chambers and defining the second expected range based upon the average value.

22. The method of claim 21 wherein deriving the average value comprises deriving a mean value of preceding intervals between depolarizations of the two chambers.

23. The method of claim 21 or claim 22, wherein defining the second expected range further comprises deriving a value of the variability of preceding measured intervals between depolarizations of the two chambers and defining the second expected range based upon the average value and the variability value.

24. The method of claim 16 or claim 21 or claim 22, wherein measuring intervals between depolarizations of the two chambers comprises measuring intervals between depolarizations of an atrium and a ventricle of the patient'"'"'s heart.

25. The method of claim 16, further comprising:

determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, determining that the patient is in a sinus rhythm.

26. An apparatus for identifying sinus rhythm in a patient'"'"'s heart, comprising:

means for measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

means for deriving an average value based upon preceding measured intervals between depolarizations of the single chamber;

means for determining a variability value based upon preceding measured intervals between depolarizations of the single chamber;

means for defining a first expected range of future measured intervals between depolarizations of the single chamber based upon the average value and the variability value; and

means responsive to future measured intervals between depolarizations of the single chamber falling within the first expected range, for determining that the patient is in a sinus rhythm.

27. The apparatus of claim 26 wherein the means for deriving the average value comprises means for deriving a mean value of preceding intervals between depolarizations of the single chamber.

28. The apparatus of claim 27 wherein deriving the mean value comprises deriving a trimmed mean value of preceding intervals between depolarizations of the single chamber.

29. The apparatus of claim 26 or claim 27 or claim 28 above, wherein the means for measuring intervals between depolarizations of the single chamber comprises means for measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

30. The apparatus of claim 29, further comprising:

means for measuring intervals between depolarizations of two chambers of the patient'"'"'s heart;

means for defining a second expected range of future measured intervals between depolarizations of the two chambers; and

means responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, for determining that the patient is in a sinus rhythm.

31. The apparatus of claim 30, further comprising:

means for determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

means responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, for determining that the patient is in a sinus rhythm.

32. The apparatus of claim 26, further comprising:

means for measuring intervals between depolarizations of two chambers of the patient'"'"'s heart;

means for defining a second expected range of future measured intervals between depolarizations of the two chambers; and

means responsive to future measured intervals between depolarizations of the two chambers falling within the second expected range, for determining that the patient is in a sinus rhythm.

33. The apparatus of claim 26, further comprising:

means for determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

means responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, for determining that the patient is in a sinus rhythm.

34. An apparatus for identifying sinus rhythm in a patient'"'"'s heart, comprising:

means for measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

means for defining a first expected range of future measured intervals between depolarizations of the single chamber, based upon the measured intervals between depolarizations of the single chamber;

means for determining whether the patient is in a 1;

1 rhythm; and

means responsive to future measured intervals between depolarizations of the single chamber falling within the first expected range while the patient is in a 1;

1 rhythm, for determining that the patient is in a sinus rhythm.

35. The apparatus of claim 34 wherein the means for defining the first expected range comprises means for deriving an average value of preceding intervals between depolarizations of the single chamber and means for defining the first expected range based upon the average value.

36. The apparatus of claim 35 wherein the means for deriving the average value comprises means for deriving a mean value of preceding intervals between depolarizations of the single chamber.

37. The apparatus of claim 35 or claim 36, wherein the means for defining the first expected range further comprises means for deriving a value of the variability of preceding measured intervals between depolarizations of the single chamber and means for defining the first expected range based upon the average value and the variability value.

38. The apparatus of claim 34 or claim 35 or claim 36, wherein the means for measuring intervals between depolarizations of the single chamber comprises means for measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

39. The apparatus of claim 38, further comprising:

means for measuring intervals between two chambers of the patient'"'"'s heart;

means for defining a second expected range of future measured intervals between depolarizations of the two chambers; and

means responsive to future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart falling within the second expected range, for determining that the patient is in a sinus rhythm.

40. The apparatus of claim 34, further comprising:

means for measuring intervals between two chambers of the patient'"'"'s heart;

means for defining a second expected range of future measured intervals between depolarizations of the two chambers; and

means responsive to future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart falling within the second expected range, for determining that the patient is in a sinus rhythm.

41. An apparatus for identifying sinus rhythm in a patient'"'"'s heart, comprising:

means for measuring intervals between depolarizations of a single chamber of a patient'"'"'s heart;

means for measuring intervals between two chambers of the patient'"'"'s heart;

means for defining a first expected range of future measured intervals between depolarizations of the single chamber of a patient'"'"'s heart;

means for defining a second expected range of future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart; and

means responsive to future measured intervals between depolarizations of the single chamber of a patient'"'"'s heart falling within the first expected range and to future measured intervals between depolarizations of the two chambers of the patient'"'"'s heart falling within the second expected range, for determining that the patient is in a sinus rhythm.

42. The apparatus of claim 41 wherein the means for defining the first expected range comprises means for deriving an average value of preceding intervals between depolarizations of the single chamber and means for defining the first expected range based upon the average value.

43. The apparatus of claim 42 wherein the means for deriving the average value comprises means for deriving a mean value of preceding intervals between depolarizations of the single chamber.

44. The apparatus of claim 42 or claim 43, wherein the means for defining the first expected range further comprises deriving a value of the variability of preceding measured intervals and means for defining the first expected range based upon the average value and the variability value.

45. The apparatus of claim 41 or claim 42 or claim 43, wherein the means for measuring intervals between depolarizations of the single chamber of the patient'"'"'s heart comprises means for measuring intervals between depolarizations of a ventricle of the patient'"'"'s heart.

46. The apparatus of claim 41 wherein the means for defining the second expected range comprises means for deriving an average value of preceding intervals between depolarizations of the two chambers and defining the second expected range based upon the average value.

47. The apparatus of claim 46 wherein the means for deriving the average value comprises means for deriving a mean value of preceding intervals between depolarizations of the two chambers.

48. The apparatus of claim 46 or claim 47, wherein the means for defining the second expected range further comprises means for deriving a value of the variability of preceding measured intervals and means for defining the second expected range based upon the average value and the variability value.

49. The apparatus of claim 41 or claim 46 or claim 47, wherein the means for measuring intervals between depolarizations of the two chambers comprises means for measuring intervals between depolarizations of an atrium and a ventricle of the patient'"'"'s heart.

50. The apparatus of claim 41, further comprising:

means for determining whether the patient'"'"'s heart is in a 1;

1 rhythm; and

means responsive to a determination that the patient'"'"'s heart is in a 1;

1 rhythm, for determining that the patient is in a sinus rhythm.