Method and apparatus for affecting atrial defibrillation with bi-atrial pacing

• US 20030069609A1
• Filed: 10/09/2001
• Published: 04/10/2003
• Est. Priority Date: 10/09/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Thompson, David L.
• Granted Patent: US 7,027,861 B2
• Time in Patent Office: Days
• US Class Current: 607/14
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

A method and apparatus for cardioverting the atrium of a human heart that includes insertion of first and second elongated electrodes tranvenously into the heart and associated vessels. One electrode is preferably located in the coronary sinus and great vein of the heart. The other electrode is preferably located in the vicinity of the right atrium of the heart, spaced from the electrode located in the coronary sinus. In response to detection of fibrillation or in response to manual triggering, a defibrillation pulse is applied between the first and second electrodes to effect atrial cardioversion. Further, after delivery of a successful defibrillation shock, the width of intrinsic p-waves are monitored and bi-atrial pacing is temporarily initiated if the width exceeds a preset or programmable threshold.

Claims

1. An implantable medical device, comprising:

means for delivering a first therapy in response to variations in heart rhythm of a patient;

means for determining whether the first therapy was successful;

means for determining, in response to delivery of the first therapy being successful, variations in a subsequent waveform representation of a cardiac cycle of the patient; and

means for delivering a second therapy in response to the determined variations.

2. The device of claim 1, wherein the means for determining variations determines whether a width of a p-wave is greater than a predetermined threshold width.

3. The device of claim 1, wherein the means for delivering a second therapy delivers the second therapy for a predetermined time period.

4. The device of claim 3, wherein the predetermined time period is between approximately 1 and 5 minutes.

5. The device of claim 1, wherein the means for determining variations determines, after delivery of the second therapy, whether a width of a subsequent p-wave is greater than a predetermined threshold width.

6. The device of claim 5, wherein the means for delivering a second therapy repeats delivery of the second therapy in response to the width of the subsequent p-wave being greater than the predetermined threshold width.

7. The device of claim 2 wherein the predetermined threshold width is greater than a normal intrinsic width of a p-wave.

8. The device of claim 7, wherein the predetermined threshold width is between approximately 10 and 50 msec greater than the normal intrinsic width of a p-wave.

9. The device of claim 2, wherein the predetermined threshold width is of a proportionately greater measure over a normal width of a p-wave.

10. The device of claim 9, wherein the proportionately greater measure includes a percent increase between approximately 5 and 20 percent.

11. The device of claim 1, wherein the first therapy is a defibrillation pulse and the second therapy is bi-atrial pacing.

12. The device of claim 1, further comprising means for amplifying a signal between electrodes for generating the subsequent waveform representation.

13. The device of claim 12, wherein the electrodes comprise subcutaneous electrode array electrodes.

14. An implantable medical device for delivering a first therapy in response to variations in heart rhythm detected by electrodes inserted within a patient, comprising:

an amplifier amplifying a signal between the electrodes to generate amplified p-waves;

a pacer timing/control circuit receiving the p-waves and detecting, in response to the first therapy being successful, variations in subsequent generated p-waves, wherein a second therapy is delivered in response to the detected variations in subsequent generated p-waves.

15. The device of claim 14, wherein the pacer timing/control circuit determines whether a width of a p-wave is greater than a predetermined threshold width.

18. The device of claim 15 wherein the predetermined threshold width is greater than a normal intrinsic width of a p-wave.

19. The device of claim 18, wherein the predetermined threshold width is between approximately 10 and 50 msec greater than the normal intrinsic width of a p-wave.

20. The device of claim 15, wherein the predetermined threshold width is a proportionately greater measure over a normal width of a p-wave.

21. The device of claim 20, wherein the proportionately greater measure includes a percent increase between approximately 5 and 20 percent.

22. The device of claim 14, wherein the first therapy is a defibrillation pulse and the second therapy is bi-atrial pacing.

23. The device of claim 14, wherein the electrodes comprise subcutaneous electrode array electrodes.

16. The device of claim 16, wherein the pacer timing/control circuit determines, subsequent to delivery of the second therapy, whether a width of a subsequent p-wave is greater than a predetermined threshold width.

17. The device of claim 16, wherein delivery of the second therapy is repeated in response to the width of the subsequent p-wave being greater than the predetermined threshold width.

24. A method for implementing atrial defibrillation, comprising the steps of:

delivering a first therapy in response to variations in heart rhythm of a patient;

determining whether the first therapy was successful;

determining, in response to delivery of the first therapy being successful, variations in a subsequent waveform representation of a cardiac cycle of the patient; and

delivering a second therapy in response to the determined variations.

25. The method of claim 24, wherein the step of determining variations determines whether a width of a p-wave is greater than a predetermined threshold width.

26. The method of claim 24, wherein the second therapy is delivered for a predetermined time period.

27. The method of claim 26, wherein the predetermined time period is between approximately 1 and 5 minutes.

28. The method of claim 24, wherein the step of determining variations further comprises determining, after delivery of the second therapy, whether a width of a subsequent p-wave is greater than a predetermined threshold width.

29. The method of claim 28, wherein delivery of the second therapy is repeated in response to the width of the subsequent p-wave being greater than the predetermined threshold width.

30. The method of claim 25 wherein the predetermined threshold width is greater than a normal intrinsic width of a p-wave.

31. The method of claim 30, wherein the predetermined threshold width is between approximately 10 and 50 msec greater than the normal intrinsic width of a p-wave.

32. The method of claim 25, wherein the predetermined threshold width is of a proportionately greater measure over a normal width of a p-wave.

33. The method of claim 32, wherein the proportionately greater measure includes a percent increase between approximately 5 and 20 percent.

34. The method of claim 24, further comprising the step of amplifying a signal between electrodes for generating the subsequent waveform representation.

35. The method of claim 34, wherein the electrodes comprise subcutaneous electrode array electrodes.