EXTRA-CARDIAC IMPLANTABLE DEVICE WITH FUSION PACING CAPABILITY

• US 20090275998A1
• Filed: 04/29/2009
• Published: 11/05/2009
• Est. Priority Date: 04/30/2008
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Dolan, Becky Lynn, Burnes, John E.
• Application Number:
  US12/432,502
• Publication Number:
  US 20090275998A1
• Time in Patent Office: Days
• US Class Current: 607/4
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• 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 1/3682 with a variable atrioventricular delay

Abstract

According to this disclosure, a non-transvenous pacing and, optionally defibrillation, therapy device is implanted subcutaneously and oriented to provide cardiac sensing from electrodes spaced from a heart and deliver pacing and/or defibrillation from one or more non-transvenous electrodes (e.g., an epicardial or pericardial electrode or electrode patch). A subject receiving a device according to this disclosure is monitored to confirm a relatively stable bundle branch block (i.e., delayed activation) of one ventricle. The subcutaneous device has electrodes disposed on the housing and/or having an electrode on a subcutaneous medical lead is oriented so that the pacing (and sensing) vector impinges mainly upon the one ventricle, and/or optionally an epicardial or pericardial lead is deployed to a last-to-depolarize ventricle (e.g., a left ventricle) so that single-ventricular pacing is delivered to achieve fusion depolarization of both ventricles.

Claims

1. A method of delivering a single-ventricular fusion-type pacing therapy, comprising:

a) detecting an atrial depolarization during a cardiac cycle from a far-field sensing array coupled to an extra-cardiac implantable medical device and spaced from the myocardium;

b) detecting an associated intrinsic ventricular depolarization during the cardiac cycle;

c) measuring the time elapsed between the detected P-wave and the detected R-wave;

d) decrementing the measured elapsed time interval by a predetermined amount to produce a defined delay;

e) initiating the defined delay responsive to subsequent sensed atrial depolarizations; and

f) delivering a pacing stimulus to a single ventricle via a non-transvenous electrode at expirations of the defined delays.

3. A method according to claim 1, wherein detecting the R-wave comprises sensing the R-wave using the far-field sensing array.

5. A method according to claim 1, further comprising:

detecting an arrhythmia via one of the far-field sensing array, an epicardial patch-type assembly, a pericardial electrode, and a helical screw-type electrode;

ceasing delivery of the single-ventricular fusion-pacing therapy; and

delivering one of an anti-tachycardia pacing sequence and a defibrillation therapy.

6. A method according to claim 5, wherein detecting the arrhythmia comprises detecting a ventricular arrhythmia.

7. A method according to claim 1, further comprising detecting a failure to reliably sense P-waves and in response thereto switching to an R-wave triggered pacing therapy.

8. A method according to claim 7, wherein detecting a failure to reliably sense P-waves comprises detecting R-waves or delivered pacing pulses without associated preceding detected P-waves.

9. A method according to claim 7, wherein detecting a failure to reliably sense P-waves comprises determining the regularity of timing of sensed P-waves

10. A method according to claim 1, further comprising detecting reverse ventricular remodeling and in response thereto switching to an alternate pacing therapy.

11. A method according to claim 1, further comprising detecting reverse ventricular remodeling and in response thereto allowing normal, un-paced sinus rhythm to resume.

12. A method according to claim 9, wherein detecting reverse ventricular remodeling comprises analysis of morphologies of detected R-waves.

13. A method according to claim 1, further comprising analysis of morphologies of detected R-waves and variation of the defined delay in response thereto.

14. A method according to claim 13, further comprising analysis of morphologies of detected R-waves comprises measuring widths of the detected R-waves.

15. A method according to claim 13, wherein analysis of morphologies of detected R- waves comprises analysis of morphologies of detected R- waves sensed using the far-field sensing array.

2. A method according to claim 2, wherein the decrementing amount is between about 10 milliseconds (ms) and about 50 ms.

4. A method according to claim 4, wherein detecting the R-wave comprises sensing the R-wave using a myocardial or pericardial electrode.

16. An apparatus for establishing a fusion pacing delay interval for a cardiac therapy device, comprising:

a) means for detecting an atrial depolarization during a cardiac cycle comprising a far-field sensing array coupled to an implantable medical device and spaced from the myocardium;

b) means for detecting an intrinsic ventricular depolarization during the cardiac cycle;

c) means for measuring the time interval elapsed between the detected atrial depolarization and the detected ventricular depolarization;

d) means for decrementing the measured interval by a predetermined amount to produce a defined delay;

e) means for timing the defined delay following a sensed atrial depolarization; and

f) means for delivering a pacing stimulus to a single ventricle using an electrode located exterior to the heart at the expiration of the defined delay.

17. An apparatus according to claim 16, wherein the predetermined decrementing amount is an interval of between about 10 milliseconds (ms) and about 50 ms.

18. An apparatus according to claim 16, wherein the electrode comprises one of an epicardial electrode, a myocardial electrode, a pericardial electrode, a subcutaneous electrode.

19. An apparatus according to claim 16, wherein the means for detecting the R-wave comprises one of an epicardial electrode, a myocardial electrode, a pericardial electrode, a subcutaneous electrode.

20. An apparatus according to claim 16, further comprising:

means for detecting an arrhythmia;

means for ceasing delivery of the single-ventricular fusion-pacing therapy; and

means responsive to detection of an arrhythmia for delivering one of an anti-tachycardia pacing (ATP) sequence and a defibrillation therapy.

21. An apparatus according to claim 20, wherein the means for detecting an arrhythmia comprises means for detecting a ventricular arrhythmia.

22. An apparatus according to claim 16, further comprising means for detecting a failure to reliably sense P-waves and in response thereto switching to an R-wave triggered pacing therapy.

23. An apparatus according to claim 22, wherein the means for detecting a failure to reliably sense P-waves comprises means for detecting R-waves or delivered pacing pulses without associated preceding detected P-waves.

24. An apparatus according to claim 22, wherein detecting a failure to reliably sense P-waves comprises determining the regularity of timing of sensed P-waves

25. An apparatus according to claim 16, further comprising means for detecting reverse ventricular remodeling and in response thereto switching to an alternate pacing therapy.

26. An apparatus according to claim 16, further comprising means for detecting reverse ventricular remodeling and in response thereto allowing normal, un-paced sinus rhythm to resume.

27. An apparatus according to claim 26, wherein the means for detecting reverse ventricular remodeling comprises means for analysis of morphologies of detected R-waves.

28. An apparatus according to claim 16, further comprising means for analysis of morphologies of detected R-waves and variation of the defined delay in response thereto.

29. An apparatus according to claim 28, wherein the means for analysis of morphologies of detected R-waves comprises means for measuring widths of the detected R-waves.

30. An apparatus according to claim 29, wherein analysis of morphologies of detected R-waves comprises analysis of morphologies of detected R-waves sensed using the far-field sensing array.

31. A cardiac therapy apparatus for delivering single-ventricular fusion pacing therapy, comprising:

a) a P-wave detecting circuit coupled to a far-field subcutaneous electrode array;

b) an R-wave detecting circuit coupled to the subcutaneous electrode array;

c) a timer measuring the time elapsed between a detected P-wave and a detected R-wave;

d) means for decrementing the measured elapsed time by a predetermined amount to determine a defined delay;

e) a pacing timer timing the defined delay following a sensed P-wave; and

f) a pacing pulse generator coupled to a non-transvenous electrode, delivering a pacing pulse responsive to expiration of the defined delay.

32. A cardiac therapy device according to claim 31 wherein the non-transvenous electrode comprises one of an epicardial electrode, a myocardial electrode, a pericardial electrode, a subcutaneous electrode.