System to treat AV-conducted ventricular tachyarrhythmia

• US 20060224202A1
• Filed: 04/05/2005
• Published: 10/05/2006
• Est. Priority Date: 04/05/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Moffitt, Julia, Kramer, Andrew P., Libbus, Imad
• Granted Patent: US 7,555,341 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• 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
• 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 1/39622 Pacing therapy
• CPC Class Codes: A61N 2001/0585 Coronary sinus electrodes

Abstract

Various aspects of the present subject matter provide devices and methods to treat AV-conducted ventricular tachyarrhythmia (AVCVT). According to various embodiments of the method, an AVCVT is sensed, an IVC-LA fat pad is stimulated when the AVCVT is sensed to block AV conduction, and bradycardia support pacing is provided while the IVC-LA fat pad is stimulated. Other aspects and embodiments are provided herein.

Claims

1. An implantable medical device, comprising:

at least one port, each port being adapted to connect at least one lead that has at least one electrode;

a sensing circuit connected to the at least one port to sense at least one intrinsic signal for use in determining an AV-Conducted Ventricular Tachyarrhythmia (AVCVT) event;

a neural stimulation circuit connected to the at least one port to selectively apply a neural stimulation signal to an IVC-LA fat pad located between an inferior vena cava and a left atrium;

a pacing circuit connected to the at least one port to provide bradycardia support pacing to maintain at least a programmable minimum heart rate; and

a controller connected to the sensing circuit, the neural stimulation circuit and the pacing circuit, the controller being adapted to determine the AVCVT event from the at least one intrinsic signal sensed by the sensing circuit, apply the neural stimulation signal to the IVC-LA fat pad during the AVCVT event to block AV conduction to terminate the AVCVT event, and provide bradycardia support pacing when the neural stimulation signal is applied to the IVC-LA fat pad.

2. The device of claim 1, wherein the neural stimulation signal includes a signal with a magnitude of approximately 10 Volts, a frequency of approximately 30 Hz, and a duration of approximately 0.05 ms.

3. The device of claim 1, wherein the controller is adapted to adjust the neural stimulation signal to further slow AV conduction if the AVCVT event is not terminated with an initial application of the neural stimulation signal to the IVC-LA fat pad.

4. The device of claim 1, wherein the controller is adapted to adjust an amplitude of the neural stimulation signal.

5. The device of claim 1, wherein the controller is adapted to adjust a frequency of the neural stimulation signal.

6. The device of claim 1, wherein the controller is adapted to adjust a burst frequency of the neural stimulation signal.

7. The device of claim 1, wherein the controller is adapted to adjust a wave morphology of the neural stimulation signal.

8. The device of claim 1, wherein the sensing circuit is adapted to sense an atrial rate for use in determining the AVCVT event using a sensed intrinsic signal from a right atrium.

9. The device of claim 1, wherein the sensing circuit is adapted to sense a ventricular rate using a sensed intrinsic signal from a right ventricle for use in comparing to the atrial rate and determining the AVCVT event.

10. The device of claim 1, wherein the pacing circuit is adapted to sense an intrinsic ventricular rate and provide ventricular pacing to maintain at least the programmable minimum heart rate.

11. The device of claim 1, wherein the pacing circuit is adapted to sense an intrinsic right ventricular contraction and provide bradycardia support pacing to the right ventricle to maintain at least the programmable minimum heart rate.

12. The device of claim 1, wherein the controller is adapted to identify a ventricular refractory period and to control delivery of the neural stimulation based on the ventricular refractory period to avoid capturing ventricular tissue with the neural stimulation.

13. An implantable medical device, comprising:

a header, including;

a first port to connect to a first lead with at least one electrode to be located to sense intrinsic signals from a right atrium;

a second port to connect to a second lead with at least one electrode to be located to sense intrinsic signals from and provide electrical stimulation to a right ventricle; and

at least a third port to connect to at least a third lead to be intravascularly inserted through a coronary sinus with at least one electrode located to sense intrinsic signals from and provide electrical stimulation to a left ventricle and at least one electrode located to stimulate an IVC-LA fat pad located between an inferior vena cava and a left atrium;

a right atrium detector connected to the first port of the header to sense an atrial rate based on intrinsic signals from the right atrium for use in determining an AV-Conducted Ventricular Tachyarrhythmia (AVCVT) event;

a right ventricle detector connected to the second port of the header to sense a ventricular rate based on intrinsic signals from the right ventricle for use in determining the AVCVT event;

a neural stimulator connected to the at least one third port of the header to selectively apply a neural stimulation signal to the IVC-LA fat pad during the AVCVT event to slow AV conduction and terminate the AVCVT event; and

a cardiac pacing stimulator connected to the second port and the at least one third port to provide bradycardia support pacing to maintain at least a programmable minimum heart rate when the neural stimulation signal is applied to the IVC-LA fat pad and to provide biventricular pacing as part of a cardiac resynchronization therapy.

14. The implantable medical device of claim 13, wherein the at least a third port to connect to at least a third lead includes one port to connect to one lead to be transvascularly inserted through the coronary sinus, the one lead having at least one electrode located to sense intrinsic signals from and provide electrical stimulation to a left ventricle and further having at least one electrode located to stimulate an IVC-LA fat pad.

15. The implantable medical device of claim 13, wherein the at least a third port to connect to at least a third lead includes two ports to connect to two leads to be transvascularly inserted through the coronary sinus, one of the two leads having at least one electrode located to sense intrinsic signals from and provide electrical stimulation to a left ventricle and the other one of the two leads having at least one electrode located to stimulate the IVC-LA fat pad.

16. The implantable medical device of claim 13, wherein the neural stimulation signal includes a signal with a magnitude of approximately 10 Volts, a frequency of approximately 30 Hz, and a duration of approximately 0.05 ms.

17. The implantable medical device of claim 13, wherein the neural stimulator is adapted to adjust an amplitude of the neural stimulation signal.

18. The implantable medical device of claim 13, wherein the neural stimulator is adapted to adjust a frequency of the neural stimulation signal.

19. The implantable medical device of claim 13, wherein the neural stimulator is adapted to adjust a burst frequency of the neural stimulation signal.

20. The implantable medical device of claim 13, wherein the neural stimulator is adapted to adjust a wave morphology of the neural stimulation signal.

21. The implantable medical device of claim 13, wherein the neural stimulator is adapted to adjust a combination of two or more of an amplitude, a frequency, a burst frequency, and a wave morphology of the neural stimulation signal.

22. An implantable device, comprising:

means for sensing an atrial tachyarrhythmia;

means for stimulating an IVC-LA fat pad located between an inferior vena cava and a left atrium in response to a sensed atrial tachyarrhythmia to block AV conduction and terminate AV-Conducted Ventricular Tachyarrhythmia (AVCVT); and

means for providing bradycardia support pacing when the IVC-LA fat pad is stimulated.

23. The device of claim 22, wherein the means for sensing an atrial tachycardia includes means for sensing a heart rate and identifying when the heart rate exceeds a threshold value.

24. The device of claim 22, wherein the means for stimulating an IVC-LA fat pad includes an intravascular lead adapted to be fed into a coronary sinus.

25. The device of claim 24, wherein the intravascular lead includes an intravascular bipolar electrode to transvascularly stimulate the IVC-LA fat pad from the coronary sinus.

26. The device of claim 24, wherein the intravascular lead includes a bipolar electrode to pierce through the coronary sinus and be fixed in the IVC-LA fat pad.

27. The device of claim 24, wherein the means for stimulating an IVC-LA fat pad includes an epicardial lead with a bipolar electrode adapted to be fixed to the IVC-LA fat pad.

28. A method to treat AV-Conducted Ventricular Tachyarrhythmia (AVCVT), comprising:

sensing an AVCVT;

stimulating an IVC-LA fat pad when the AVCVT is sensed to selectively block AV conduction; and

providing bradycardia support pacing while the IVC-LA fat pad is stimulated.

29. The method of claim 28, wherein stimulating an IVC-LA fat pad includes applying a neural stimulation signal having a magnitude of approximately 10 Volts, a frequency of approximately 30 Hz, and a duration of approximately 0.05 ms.

30. The method of claim 28, wherein sensing an AVCVT includes sensing a heart rate and declaring an AVCVT event when the heart rate is above a threshold.

31. The method of claim 28, wherein sensing an AVCVT includes sensing a right atrial rate and declaring an AVCVT event when the right atrial rate is above a threshold.

32. The method of claim 28, wherein sensing an AVCVT includes:

sensing a right atrial rate;

sensing a right ventricular rate;

declaring an AVCVT event when the right ventricular rate is above a threshold and the right ventricular rate tracks with the right atrial rate.

33. The method of claim 28, wherein stimulating an IVC-LA fat pad includes stimulating the IVC-LA fat pad through an epicardial lead with an electrode fixed to the IVC-LA fat pad.

34. The method of claim 28, wherein stimulating an IVC-LA fat pad includes stimulating the IVC-LA fat pad through an intravascular lead in a coronary sinus with an electrode pierced through the coronary sinus and fixed to the IVC-LA fat pad.

35. The method of claim 28, wherein stimulating an IVC-LA fat pad includes stimulating the IVC-LA fat pad through an intravascular lead in a coronary sinus with an intravascular bipolar electrode to transvascularly stimulate the IVC-LA fat pad from the coronary sinus.

36. The method of claim 28, wherein stimulating an IVC-LA fat pad includes increasing a stimulation intensity to the IVC-LA fat pad if the AVCVT is not terminated after an initial stimulation of the IVC-LA fat pad.

37. The method of claim 36, wherein increasing a stimulation intensity includes adjusting an amplitude of a neural stimulation signal applied to the IVC-LA fat pad.

38. The method of claim 36, wherein increasing a stimulation intensity includes adjusting a frequency of a neural stimulation signal applied to the IVC-LA fat pad.

39. The method of claim 36, wherein increasing a stimulation intensity includes adjusting a burst frequency of a neural stimulation signal applied to the IVC-LA fat pad.

40. The method of claim 36, wherein increasing a stimulation intensity includes adjusting a wave morphology of a neural stimulation signal applied to the IVC-LA fat pad.

41. The method of claim 28, wherein the AVCVT includes a PAT event, and stimulating an IVC-LA fat pad terminates the AVCVT and the PAT event.

42. The method of claim 28, wherein stimulating an IVC-LA fat pad includes identifying a ventricular refractory period and controlling delivery of the neural stimulation based on the ventricular refractory period to avoid capturing ventricular tissue with the neural stimulation.