Capture detection for multi-chamber pacing

• US 20060247694A1
• Filed: 04/28/2005
• Published: 11/02/2006
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Meyer, Scott A., Dong, Yanting, Stalsberg, Kevin John
• Granted Patent: US 7,392,088 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

Multi-chamber pacing may result in capture of one chamber, capture of multiple chambers, fusion, or non-capture. Approaches for detecting various capture conditions during multi-chamber pacing are described. Pacing pulses are delivered to left and right heart chambers during a cardiac cycle. A cardiac electrogram signal is sensed following the delivery of the pacing pulses. Left chamber capture only, right chamber capture only, and bi-chamber capture may be distinguished based on characteristics of the cardiac electrogram signal. Multi-chamber capture detection may be implemented using detection windows having dimensions of time and amplitude. The detection windows are associated with expected features, such as expected signal peaks, under a particular capture condition. The cardiac electrogram signal features are compared to detection windows to determine the capture condition.

Claims

1. A method, comprising:

delivering a pacing pulse to a left heart chamber during a cardiac cycle;

delivering a pacing pulse to a right heart chamber during the cardiac cycle;

sensing a cardiac electrogram signal following the pacing pulses; and

distinguishing between at least two of left chamber capture only, right chamber capture only, and bi-chamber capture based on characteristics of the cardiac electrogram signal.

2. The method of claim 1, wherein distinguishing between at least two of left chamber capture only, right chamber capture only, and bi-chamber capture comprises distinguishing between left chamber capture only, right chamber capture only, and bi-chamber capture.

3. The method of claim 1, wherein:

delivering the pacing pulse to the left heart chamber comprises delivering the pacing pulse to a left ventricle;

delivering the pacing pulse to the right heart chamber comprises delivering the pacing pulse to a right ventricle; and

distinguishing between the at least two of left chamber capture only, right chamber capture only, and bi-chamber capture comprises distinguishing between at least two of left ventricular capture only, right ventricular capture only, and bi-ventricular capture.

4. The method of claim 1, wherein sensing the cardiac electrogram signal comprises sensing the cardiac electrogram signal using right heart chamber electrode.

5. The method of claim 1, wherein sensing the cardiac electrogram signal comprises sensing the cardiac electrogram signal using a left heart chamber electrode.

6. The method of claim 1, wherein sensing the cardiac electrogram signal comprises sensing the cardiac electrogram signal using a left heart chamber electrode and a right heart chamber electrode.

7. The method of claim 1, wherein sensing the cardiac electrogram signal comprises sensing the cardiac electrogram signal using a first electrode, and further comprising:

sensing an additional cardiac electrogram signal using a second electrode; and

confirming left chamber capture only, right chamber capture only or bi-chamber capture based on characteristics of the additional cardiac electrogram signal.

8. The method of claim 7, wherein:

distinguishing between at least two of left chamber capture only, right chamber capture only, and bi-chamber capture comprises distinguishing between a first two of left chamber capture only, right chamber capture only, and bi-chamber capture based on characteristics of the cardiac electrogram signal; and

confirming left chamber capture only, right chamber capture only or bi-chamber capture comprises distinguishing between a second two of left chamber capture only, right chamber capture only or bi-chamber capture based on characteristics of the additional cardiac electrogram signal.

9. The method of claim 1, wherein sensing the cardiac electrogram signal comprises:

selecting an electrode from a plurality of electrodes for sensing the cardiac electrogram signal, the electrode selection based on suitability of the electrode for capture discrimination; and

sensing the cardiac electrogram signal using the selected electrode.

10. The method of claim 1, wherein distinguishing between the at least two of left chamber capture only, right chamber capture only, and bi-chamber capture comprises:

providing templates associated with each of left chamber capture, right chamber capture, and bi-chamber capture;

comparing the cardiac electrogram signal to one or more of the templates; and

distinguishing between the at least two of left chamber capture only, right chamber capture only, and bi-chamber capture based on the comparison.

11. The method of claim 10, wherein each template comprises one or more detection windows associated with left chamber capture, right chamber capture or bi-ventricular capture.

12. The method of claim 11, wherein the one or more detection windows have parameters of time and amplitude.

13. The method of claim 11, wherein each detection window is associated with an expected characteristic of the cardiac electrogram under a particular capture condition.

14. The method of claim 13, wherein the expected characteristic comprises a peak of the cardiac electrogram signal.

15. The method of claim 1, wherein delivering the pacing pulse to the left heart chamber and delivering the pacing pulse to the right heart chamber comprises delivering the pacing pulse to the left heart chamber and delivering the pacing pulse to the right heart chamber through separate channels.

16. The method of claim 1, wherein delivering the pacing pulse to the left heart chamber and delivering the pacing pulse to the right heart chamber comprises delivering the pacing pulses separated in time by an interventricular delay.

17. The method of claim 1, wherein distinguishing between the at least two of left chamber capture only, right chamber capture only, and bi-chamber capture further comprises distinguishing between left chamber capture only, right chamber capture only, bi-chamber capture, fusion, and non-capture of the left and right heart chambers.

18. A cardiac device, comprising:

sensing circuitry comprising cardiac electrodes and configured to sense an cardiac electrogram signal following delivery of pacing pulses delivered to left and right heart chambers, respectively, during a cardiac cycle; and

a processor coupled to the sensing circuitry, the processor configured to distinguish between at least two of left chamber capture only, right chamber capture only, and bi-chamber capture based on characteristics of the cardiac electrogram signal.

19. The device of claim 18, wherein the processor is configured to distinguish between left chamber capture only, right chamber capture only, and bi-chamber capture based on characteristics of the cardiac electrogram signal.

20. The device of claim 18, wherein the processor is configured to distinguish between left chamber capture only, right chamber capture only, bi-chamber capture, fusion and non-capture of either chamber.

21. The device of claim 18, wherein the sensing circuitry comprises an electrode positioned in the right heart chamber and the sensing channel is configured to sense the cardiac electrogram signal using a right heart chamber electrode.

22. The device of claim 18, wherein the sensing circuitry comprises an electrode positioned within a vein of the left heart chamber and the sensing channel is configured to sense the cardiac electrogram signal using a left heart chamber electrode;

23. The device of claim 18, wherein the sensing circuitry comprises electrodes positioned within a vein of the left heart chamber and in the right heart chamber and the sensing channel is configured to sense the cardiac electrogram signal using the left heart chamber electrode and the right heart chamber electrode.

24. The device of claim 18, wherein the processor is configured to select an electrode from the plurality of electrodes for sensing the cardiac electrogram signal, the electrode selection based on suitability of the selected electrode for capture discrimination.

25. The device of claim 18, wherein:

the sensing circuitry is configured to sense an additional cardiac electrogram signal; and

the processor is configured to confirm left chamber capture only, right chamber capture only or bi-chamber capture based on characteristics of the additional cardiac electrogram signal.

26. The device of claim 18, wherein the processor is configured to compare the cardiac electrogram signal to one or more templates, each template associated with at least one of left chamber capture, right chamber capture, and bi-chamber capture.

27. The device of claim 26, wherein each template comprises one or more detection windows associated with expected characteristics of the cardiac electrogram signal under conditions of left chamber capture, right chamber capture or bi-chamber capture.

28. The device of claim 27, wherein the one or more detection windows have parameters of time and amplitude.

29. The device of claim 27, wherein the one or more expected characteristics comprise one or more peaks of the cardiac electrogram signal.

30. The device of claim 18, further comprising stimulation circuitry configured to deliver the pacing pulses to the left chamber and the right chamber.

31. The device of claim 30, wherein the stimulation circuitry is configured to deliver the pacing pulses to a left ventricle and a right ventricle, the delivered pacing pulses separated in time by an interventricular delay.

32. A cardiac response detection system, comprising:

a pulse generator configured to deliver pacing pulses to left and right heart chambers, respectively, during a cardiac cycle;

means for sensing a cardiac electrogram signal following the pacing pulses; and

means for distinguishing between at least two of multi-chamber capture, left chamber capture only, and right chamber capture only based on characteristics of the cardiac electrogram signal.

33. The system of claim 32, further comprising means for distinguishing between bi-ventricular capture, left ventricular capture only, right ventricular capture only, non-capture of the left and right heart chambers, and fusion based on the characteristics of the cardiac electrogram signal.

34. The system of claim 32, further comprising:

means for providing templates associated with bi-ventricular capture, left ventricular capture, and right ventricular capture;

means for comparing the cardiac electrogram signal to one or more of the templates; and

means for distinguishing between the at least two of bi-ventricular capture, left ventricular capture only, and right ventricular capture only based on the comparison.