Cardiac rhythm management system with prevention of double counting of events

• US 20040193225A1
• Filed: 04/05/2004
• Published: 09/30/2004
• Est. Priority Date: 04/19/1999
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Esler, James A.
• Granted Patent: US 7,373,203 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• 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 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence

Abstract

A cardiac rhythm management system recognizes patterns of interval durations, distinguishing between events in different heart chambers even though signals associated with those different heart chambers are processed using a commonly shared sensing circuit. A therapy delivery algorithm ignores intervals between cardiac events occurring in different heart chambers when determining a cardiac rate upon which the delivery of therapy is based. This reduces the risk of inappropriate delivery of therapy to the patient. Delayed conduction left ventricular beats are not erroneously recognized as a subsequent right ventricular beat, preventing such short intervals from inappropriately triggering a defibrillation countershock.

Claims

1-12. -12. (canceled)

13. A method including:

(a) detecting cardiac events;

(b) obtaining intervals between cardiac events;

(c) pairing successive intervals into first-second interval pairs;

(d) classifying the intervals, based on duration, into at least first and second categories;

(e) counting, among a first predetermined number of most recent first-second interval pairs, a second predetermined number of one or more first-second interval pairs in which the first interval is in the first category and the second interval is in the second category; and

(f) determining timing of delivery of output energy based on (e).

14. The method of claim 13, in which (a) includes detecting events in one of (1) right and left ventricles, or (2) right and left atria.

15. The method of claim 13, in which (d) includes:

classifying the first interval of the first-second interval pair into the first category if it is longer than a first duration, and classifying the first interval into the second category if it is shorter than the first duration; and

classifying the second interval of the first-second interval pair into the first category if it is longer than a second duration, and classifying the second interval into the second category if it is shorter than the second duration.

16. The method of claim 13, in which the first and second durations are approximately equal.

17. The method of claim 15, including at least one of (1) classifying the first interval into the first category if it is equal to the first duration, or (2) classifying the second interval into the first category if it is equal to the second duration.

18. The method of claim 15, including at least one of (1) classifying the first interval into the second category if it is equal to the first duration, or (2) classifying the second interval into the second category if it is equal to the second duration.

19-27. -27. (Cancelled)

28. A system, including:

a first sensing circuit, adapted for being coupled to first and second leads for sensing heart signals from respective first and second heart chambers;

a therapy circuit, adapted for being coupled to the first and second leads for delivering therapy to the respective first and second heart chambers; and

a controller, controlling delivery of therapy by the therapy circuit based at least in part on signals received by the first sensing circuit, the controller including;

a classification module, classifying previous and current intervals between cardiac events based on duration;

a pattern recognition module, recognizing patterns in the current and previous intervals based on their classification; and

a therapy delivery control module, controlling timing of delivery of therapy based the intervals between cardiac events, and ignoring the current interval based on a classification of the current and previous intervals.

29. The system of claim 28, in which the first and second chambers include respective right and left ventricles.

30. The system of claim 28, in which the first and second chambers include respective right and left atria.

31. The system of claim 28, further including a first lead, adapted to be coupled to the first heart chamber and a second lead adapted to be coupled to the second heart chamber.

32. The system of claim 28, further including a remote programmer.

33. The system of claim 32, in which the remote programmer provides parameters to the classification module for adjusting the classification of the intervals.

34. A system, including:

a first sensing circuit, adapted for being coupled to first and second leads for sensing heart signals from respective first and second heart chambers;

a therapy circuit, adapted for being coupled to the first and second leads for delivering therapy to the respective first and second heart chambers; and

a controller, controlling delivery of therapy by the therapy circuit based at least in part on signals received by the first sensing circuit, the controller including;

means for classifying previous and current intervals between cardiac events based on duration;

means for recognizing patterns in the current and previous intervals based on their classification; and

a therapy delivery control module, controlling timing of delivery of therapy based the intervals between cardiac events, and ignoring the current interval based on a classification of the current and previous intervals.

35. The system of claim 34, in which the first and second chambers include respective right and left ventricles.

36. The system of claim 34, in which the first and second chambers include respective right and left atria.

37. The system of claim 34, further including a first lead, adapted to be coupled to the first heart chamber and a second lead adapted to be coupled to the second heart chamber.

38. The system of claim 34, further including a remote programmer.

39. The system of claim 38, in which the remote programmer provides parameters to the means for classifying, for adjusting the classification of the intervals.