APPARATUS AND METHOD FOR THE DETECTION AND TREATMENT OF ATRIAL FIBRILLATION

• US 20100268291A1
• Filed: 04/09/2010
• Published: 10/21/2010
• Est. Priority Date: 04/21/2009
• Status: Active Grant

• Current Assignee: InCube Labs LLC. (In-Cube, Inc.)
• Original Assignee: InCube Labs LLC. (In-Cube, Inc.)
• Inventors: Imran, Mir
• Granted Patent: US 8,731,662 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3624 occurring in the atrium, i.e. atrial tachycardia
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation

Abstract

Embodiments of the invention provide methods for the detection and treatment of atrial fibrillation (AF) and related conditions. One embodiment provides a method comprising measuring electrical activity of the heart using electrodes arranged on the heart surface to define an area for detecting aberrant electrical activity (AEA) and then using the measured electrical activity (MEA) to detect foci of AEA causing AF. A pacing signal may then be sent to the foci to prevent AF onset. Atrial wall motion characteristics (WMC) may be sensed using an accelerometer placed on the heart and used with MEA to detect AF. The WMC may be used to monitor effectiveness of the pacing signal in preventing AF and/or returning the heart to normal sinus rhythm (NSR). Also, upon AF detection, a cardioversion signal may be sent to the atria using the electrodes to depolorize an atrial area causing AF and return the heart to NSR.

Claims

1. A method for treating and/or preventing atrial fibrillation in a patient, the method comprising:

measuring electrical activity of the heart using a plurality of electrodes arranged on the surface of the heart to define a detection area for detecting aberrant electrical activity in the heart; and

detecting a foci of aberrant electrical activity in the heart causing the onset of atrial fibrillation (AF) using the measured electrical activity.

2. The method of claim 1, wherein the plurality of electrodes are positioned on an endocardial surface of the heart.

3. The method of claim 1, wherein the plurality of electrodes comprises at least three electrodes.

4. The method of claim 1, wherein the plurality of electrodes are arranged in a substantially circular or oval pattern.

5. The method of claim 1, wherein the foci is detected by identifying a location in the detection area which depolarizes before the patient'"'"'s SA node during an episode of AF.

6. The method of claim 1, wherein the foci is detected by identifying a location in the detection area which has the earliest depolarization during an episode of AF.

7. The method of claim 1, wherein the foci is detected by detecting an abnormal P wave in the patient'"'"'s EKG.

8. The method of claim 1, further comprising

sending a pacing signal to the foci to prevent the foci from causing AF.

9. The method of claim 8, wherein the pacing signal is sent continuously.

10. The method of claim 8, wherein the pacing signal is sent using an electrode of the plurality that is nearest the detected foci.

11. The method of claim 8, wherein the pacing signal is configured to produce a stimulated P wave.

12. The method of claim 11, wherein the pacing signal is triggered of the patient'"'"'s R-wave or R to R interval.

13. The method of claim 1, wherein the foci is detected by the absence or abnormality of a measured signal representative of the patient'"'"'s P-wave.

14. The method of claim 1, further comprising:

sensing a wall motion characteristic of the atria using an accelerometer placed on the wall of the atrial; and

using the sensed wall motion characteristic to detect the occurrence or absence of AF.

15. The method of claim 14, wherein the accelerometer is placed on the epicardial wall of the atria.

16. The method of claim 14, wherein the accelerometer is a 3D accelerometer.

17. The method of claim 14, wherein AF is detected using analysis of both the sensed wall motion and the measured electrical activity.

18. The method of claim 14, further comprising:

sending a pacing signal to the foci to prevent the site from causing AF, wherein the sensed wall motion characteristic is used to assess the effectiveness of the pacing signal in preventing AF and/or returning the heart to normal sinus rhythm.

19. A method for treating atrial fibrillation in a patient, the method comprising:

measuring electrical activity of the heart using a plurality of electrodes arranged on the surface of the heart to define a detection area for detecting aberrant electrical activity in the heart;

detecting a foci of aberrant electrical activity in the heart causing the onset of atrial fibrillation (AF) using the measured electrical activity; and

upon detection of AF, sending a cardioversion signal to the atria using at least a majority of the plurality of electrodes to substantially depolarize an area of the atrial myocardium, the depolarized area sufficient in size to stop the aberrant signals causing the AF.

20. The method of claim 19, wherein the atria are converted from a fibrillative state to normal sinus rhythm.

21. The method of claim 19, wherein the voltage of the cardioverison signal is in the range about 8 to 10 volts.

22. The method of claim 19, wherein the plurality of electrodes are arrange on the surface of the heart in a distributed pattern.

23. The method of claim 19, wherein the electrodes of the plurality are bipolar electrodes, the method further comprising:

controlling the penetration depth of energy delivered from the plurality of electrodes to a selected depth of the atrial myocardium.

24. The method of claim 23, wherein the penetration depth is controlled so as to substantially reduce the risk of stimulating the patient'"'"'s ventricles.

25. The method of claim 19, further comprising:

adjusting a voltage used for the cardioversion signal.

26. The method of claim 25, wherein the voltage is adjusted responsive to at least of the location or the number of foci detected.

27. The method of claim 25, wherein the voltage is adjusted responsive to the size of the area bounded by the plurality of electrodes.

28. The method of claim 25, wherein the voltage is adjusted responsive to the number of electrodes used to send the cardioverion signal.

29. The method of claim 25, wherein the voltage is adjusted to a minimum level for converting the atria from a fibrillative state to normal sinus rhythm.

30. The method of claim 25, wherein the voltage is adjusted responsive to a number of prior occurrences of AF.

31. The method of claim 25, wherein the voltage is adjusted responsive to a voltage used for cardioversion during a previous episode of AF.

32. The method of claim 19, further comprising

determining if AF still persists by measuring the electrical activity of the heart with the plurality of electrodes;

and

sending a subsequent cardioversion signal to the atria.

33. The method of claim 32, wherein the voltage of the subsequent cardioversion signal is adjusted upwards relative to the voltage of the prior cardioversion signal.