METHOD AND APPARATUS FOR TREATING SUPRAVENTRICULAR TACHYARRHYTHMIAS

• US 20030023271A1
• Filed: 03/19/1998
• Published: 01/30/2003
• Est. Priority Date: 03/19/1998
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: KENKNIGHT, BRUCE H., HSU, WILLIAM
• Granted Patent: US 6,556,862 B2
• Time in Patent Office: Days
• US Class Current: 607/4
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

A system and method for treating atrial fibrillation using atrial pacing pulses to convert an atrial fibrillation to non-fibrillation atrial arrhythmia prior to delivering a low energy cardioversion/defibrillation shock. The system and method treats atrial fibrillations by first applying a plurality of pacing pulses to the atria which converts the atrial fibrillation to non-fibrillation atrial arrhythmia. Ventricular intervals are concurrently sensed and analyzed while the plurality of electrical pacing pulses are being applied. Upon detecting a period of stable ventricular intervals, the system then proceeds to deliver a low-energy cardioverting/defibrillating pulse of electrical energy across the atria of the heart.

Claims

1. A method for treating a heart, comprising the step of:

applying a plurality of pacing pulses at a first atrial pacing location upon detecting atrial fibrillation to convert the atrial fibrillation to a non-fibrillation atrial arrhythmia;

sensing ventricular intervals while the plurality of pacing pulses are being applied at the first atrial pacing location;

analyzing the ventricular intervals to determine the stability of the ventricular interval; and

delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

2. The method according to claim 1, further including the steps of repeating the steps of applying, sensing and analyzing two or more times, including a final repeat attempt, if a period of stable ventricular intervals is not determined during the analyzing step, and delivering an atrial defibrillation shock to the heart after the final repeat attempt.

3. The method according to claim 1, where the step of applying the plurality of pacing pulses at a first atrial pacing location further includes applying the plurality of pacing pulses at the first atrial pacing location and at least a second atrial pacing location to convert the atrial fibrillation to non-fibrillation atrial arrhythmia.

4. The method according to claim 3, further including the step of sensing ventricular intervals while the plurality of electrical pacing pulses are being applied to the first atrial pacing location and at least the second atrial pacing location.

5. The method according to claim 4, further including the steps of analyzing the ventricular intervals to determine the stability of the ventricular interval and delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

6. The method according to claim 5, further including the steps of repeating the steps of applying, sensing and analyzing two or more times, including a final repeat attempt, if a period of stable ventricular intervals is not determined during the analyzing step, and delivering an atrial defibrillation shock to the heart after the final repeat attempt.

7. The method according to claim 1, further including the step of applying the plurality of pacing pulses to at least a second atrial pacing location to convert atrial fibrillation to non-fibrillation atrial arrhythmia if the plurality of pacing pulses delivered at the first atrial pacing location does not convert the atrial fibrillation to a non-fibrillation atrial arrhythmia.

8. The method according to claim 7, further including the step of sensing ventricular intervals while the plurality of electrical pacing pulses are being applied to at least the second atrial pacing location.

9. The method according to claim 8, further including the steps of analyzing the ventricular intervals to determine the stability of the ventricular interval and delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

10. The method according to claim 7, further including the step of applying the plurality of pacing pulses to the first atrial pacing location and at least the second atrial pacing location at least once during atrial fibrillation to convert the atrial fibrillation to non-fibrillation atrial arrhythmia if the plurality of pacing pulses delivered to at least the second atrial pacing location does not convert the atrial fibrillation to non-fibrillation atrial arrhythmia.

11. The method according to claim 10, further including the step of sensing ventricular intervals while the plurality of electrical pacing pulses are being applied to the first pacing location and at least the second atrial pacing location.

12. The method according to claim 11, further including the steps of analyzing the ventricular intervals to determine the stability of the ventricular intervals and delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

13. The method according to claim 10, further including the step of delivering an atrial defibrillation shock to the heart if the plurality of pacing pulses delivered to the first atrial pacing location and at least the second atrial pacing location does not convert the atrial fibrillation to non-fibrillation atrial arrhythmia.

14. The method according to claim 1, further including the step of applying a plurality of pacing pulses to the first atrial pacing location and at least a second atrial pacing location to convert the atrial fibrillation to a non-fibrillation atrial arrhythmia if the plurality of pacing pulses delivered to the first atrial pacing location does not convert the atrial fibrillation to a non-fibrillation atrial arrhythmia.

15. The method according to claim 14, further including the step of sensing ventricular intervals while the plurality of electrical pacing pulses are being applied to the first atrial pacing location and at least the second atrial pacing location.

16. The method according to claim 15, further including the steps of analyzing the ventricular intervals to determine the stability of the ventricular intervals and delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

17. The method according to claim 16, further including the step of repeating the step of applying a plurality of pacing pulses to the first atrial pacing location and at least a second atrial pacing location two or more times during atrial fibrillation if a previous attempt at applying a plurality of pacing pulses to a first atrial pacing location and at least a second atrial pacing location does not convert the atrial fibrillation to non-fibrillation atrial arrhythmia.

18. The method according to claim 17, where after the applying step has been repeated a first and a second time, the method further includes the step of delivering an atrial defibrillation shock to the heart.

19. The method according to claim 1, in which the applying step delivers the plurality of pacing pulses with an energy level between 5 to 20 times a patient'"'"'s diastolic threshold.

20. The method according to claim 1, in which the plurality of pacing pulses has a pacing rate of between 80 to 200 beats per minute.

21. The method according to claim 1, in which the plurality of pacing pulses has a pacing interval that is about 10 percent less than a patient'"'"'s intrinsic cardiac interval.

22. The method according to claim 1, where the plurality of pacing pulses are delivered over a time of between 10 to 60 seconds.

23. A method for treating a heart, comprising the step of:

applying a plurality of pacing pulses having a pacing rate of between approximately 80 to 200 beats per minute, delivered over a time of between approximately 10 to 60 seconds, and an energy level between approximately 5 to 20 times a patient'"'"'s diastolic threshold at a first atrial pacing location to convert an atrial fibrillation to a non-fibrillation atrial arrhythmia;

sensing ventricular intervals while the plurality of electrical pacing pulses are being applied to the first atrial pacing location;

analyzing the ventricular intervals to determine the stability of the ventricular interval; and

delivering a first level atrial shock to the heart during a period of stable ventricular intervals.

24. The method according to claim 23, further including the steps of repeating the steps of applying, sensing and analyzing two or more times, including a final repeat attempt, if a period of stable ventricular intervals is not determined during the analyzing step, and delivering an atrial defibrillation shock to the heart after the final repeat attempt.

25. A system for treating a heart, comprising:

an implantable housing;

a first atrial catheter attached to the implantable housing of the system, where the first atrial catheter has a first atrial electrode and a first defibrillation electrode, and is positioned within the heart with the first atrial electrode and the first defibrillation electrode in a supraventricular region of the heart;

a ventricular catheter attached to the implantable housing of the system, where the ventricular catheter has a first ventricular electrode, and is positioned within the heart with the first ventricular electrode in a right ventricular chamber of the heart; and

electronic control circuitry within the implantable housing, connected to the first atrial electrode, the first defibrillation electrode, and the first ventricular electrode and where the electronic control circuitry receives cardiac signals through the first atrial electrode and the first ventricular electrode, and upon detecting atrial fibrillation, delivers a plurality of pacing pulses to convert the atrial fibrillation to a non-fibrillation atrial arrhythmia, analyzes the ventricular intervals for stability and delivers a first level atrial shock to the heart during a period of stable ventricular intervals.

26. The system according to claim 25, where the system further includes a second atrial catheter attached to the implantable housing of the system, where the second atrial catheter has a second atrial electrode and a second defibrillation electrode, and is positioned within the heart with the second atrial electrode and the second defibrillation electrode in a supraventricular region of the heart;

and where the electronic control circuitry is connected to the second atrial electrode and the second defibrillation electrodes and receives cardiac signals through the first and second atrial electrodes and the first ventricular electrode, and upon detecting atrial fibrillation, delivers a plurality of pacing pulses to convert the atrial fibrillation to a non-fibrillation atrial arrhythmia.

27. The system according to claim 25, where if the ventricular intervals are not stable during the plurality of pacing pulses, the electronic control circuitry repeats delivery of the plurality of pacing pulses.

28. The system according to claim 27, where the electronic control circuitry repeats delivery of the plurality of pacing pulses two or more times, including a final repeat attempt, during which if a period of stable ventricular intervals is not detected the electronic control circuitry delivers an atrial defibrillation shock to the heart after the final repeat attempt.

29. A catheter, comprising:

an elongate body having a peripheral surface, a proximal end and a distal end, a first atrial electrode, a first defibrillation electrode and a second defibrillation electrode, where the first atrial electrode is positioned between the proximal end and the distal end of the elongate body, the first defibrillation electrode spaced apart and longitudinally from the first atrial electrode along the peripheral surface, and the second defibrillation electrode spaced apart and longitudinally from the first defibrillation electrode and the first atrial electrode along the peripheral surface;

a series of lateral deflections in the elongate body that occur generally within a common plane between the proximal end and distal end, and where the first atrial electrode is located on one of the series of lateral deflections;

electrically insulated conductors extending longitudinally within the elongate body from contact ends at the proximal end to the first atrial electrode, the first defibrillation electrode, and the second defibrillation electrode; and

a connector terminal at the proximal end for attaching the proximal end of the elongate body to a housing of an atrial cardioverter/defibrillator.

30. The catheter of claim 29, where the series of lateral deflections has a first lateral deflection, a second lateral deflection, and a third lateral deflection, where the first lateral deflection curves away from the longitudinal axis of the elongate body and upon reaching a first maximum deflection point curves back towards the longitudinal axis, the second lateral deflection beginning as the first lateral deflection of the elongate body returns to approximately the longitudinal axis, where the second lateral deflection is in the opposite direction of the first lateral deflection, and upon reaching a second maximum deflection point curves back towards the longitudinal axis, the first atrial electrode positioned generally at the second maximum deflection point, and the third lateral deflection beginning as the second lateral deflection of the elongate body returns to approximately the longitudinal axis, where the third lateral deflection is in the opposite direction of the second lateral deflection, and upon reaching a third maximum deflection point curves back towards the longitudinal axis of the elongate body, and upon reaching the longitudinal axis, the elongate body curves back to generally align with the longitudinal axis of the elongate body, where the first maximum deflection point is spaced longitudinally from the third maximum deflection point by distances in the range of 8 to 10 millimeters, and where the first maximum deflection point and the third maximum deflection point are spaced horizontally from the second maximum deflection point in the range of 8 to 11 millimeters.

31. The catheter of claim 30, further including a second atrial pacing electrode at the distal end of the elongate body, where the first defibrillation electrode, the first atrial electrode and the second defibrillation electrode are spaced apart and longitudinally from the second atrial pacing electrode, and where the second atrial pacing electrode has an electrically insulated conductor extending longitudinally within the elongate body from a contact end at the proximal end to the second atrial pacing electrode.