Implantable vagal stimulator for treating cardiac ischemia

• US 20060206158A1
• Filed: 03/09/2005
• Published: 09/14/2006
• Est. Priority Date: 03/09/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Libbus, Imad, Wu, Eugene Yu-Chun
• Granted Patent: US 7,613,511 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• 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 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A device and method for treating cardiac ischemia with vagal stimulation is disclosed. In one embodiment, an implantable device is configured to deliver vagal stimulation upon obtaining an indication of cardiac ischemia by analysis of a recorded electrogram.

Claims

1. A method for treating cardiac ischemia, comprising:

obtaining an indication that an episode of cardiac ischemia is occurring; and

,

delivering electrical stimulation to the vagus nerve via an implantable device.

2. The method of claim 1 wherein the indication of cardiac ischemia is angina pectoris.

3. The method of claim 1 further comprising obtaining an indication of cardiac ischemia by analyzing the morphology of a recorded electrogram.

4. The method of claim 1 further comprising:

sensing intrinsic cardiac activity in one or more cardiac chambers;

delivering paces to a cardiac chamber in accordance with a programmed pacing mode such that a pace is delivered after expiration of an escape interval without sensing intrinsic activity in that chamber, and wherein the rate at which paces are delivered is limited to be below a specified maximum pacing rate;

sensing an evoked response to a pace and recording an electrogram therefrom; and

,

analyzing the recorded electrogram in order to detect a change indicative of cardiac ischemia.

5. The method of claim 4 wherein a change in the recorded electrogram indicative of cardiac ischemia are detected by looking for an increased current of injury in the recorded electrogram.

6. The method of claim 5 wherein an increased current of injury is looked for by cross-correlating the recorded electrogram with a reference electrogram.

7. The method of claim 3 further comprising obtaining an indication of cardiac ischemia only if a dyspneic breathing pattern is also detected.

8. The method of claim 1 further comprising delivering vagal stimulation upon manual operation of a tactilely or magnetically actuated switch of the implantable device.

9. The method of claim 1 further comprising delivering vagal stimulation upon both manual operation of a tactilely or magnetically actuated switch of the implantable device and an indication of cardiac ischemia obtained by analyzing the morphology of a recorded electrogram.

10. The method of claim 9 further comprising delivering vagal stimulation only if a dyspneic breathing pattern is detected.

11. An implantable cardiac device, comprising:

one or more sensing channels for sensing intrinsic cardiac activity;

a neural stimulation channel for delivering vagal stimulation;

a controller programmed to record an electrogram from the sensing channel and analyze the recorded electrogram in order to detect a change indicative of cardiac ischemia; and

,

wherein the controller is also programmed to deliver vagal stimulation upon obtaining an indication of cardiac ischemia.

12. The device of claim 11 further comprising:

a pacing channel for pacing a cardiac chamber;

wherein the controller is programmed to deliver paces to the cardiac chamber in accordance with a programmed pacing mode; and

,

wherein the controller is programmed to record an electrogram from the sensed evoked response and analyze the recorded electrogram in order to detect a change indicative of cardiac ischemia.

13. The device of claim 11 wherein the controller is further programmed to log a detected change in the electrogram indicative of cardiac ischemia as a clinically significant event.

14. The device of claim 11 further comprising a tactilely actuated switch which when manually operated causes delivery of vagal stimulation.

15. The device of claim 14 wherein the controller is further programmed to deliver vagal stimulation upon both manual operation of the tactilely actuated switch of the implantable device and an indication of cardiac ischemia obtained by analyzing the morphology of a recorded electrogram.

16. The device of claim 11 further comprising a magnetically actuated switch which when manually operated causes delivery of vagal stimulation.

17. The device of claim 16 wherein the controller is further programmed to deliver vagal stimulation upon both manual operation of the magnetically actuated switch of the implantable device and an indication of cardiac ischemia obtained by analyzing the morphology of a recorded electrogram.

18. The device of claim 11 further comprising a transthoracic impedance sensor and wherein the controller is programmed to obtain an indication of cardiac ischemia only if a dyspneic breathing pattern is also detected.

19. The device of claim 11 wherein the controller is programmed to detect a change in the recorded electrogram indicative of cardiac ischemia by looking for an increased current of injury in the recorded electrogram.

20. The device of claim 19 wherein the controller is programmed to look for an increased current of injury for by cross-correlating the recorded electrogram with a reference electrogram.