System and method for delivery of cardiac pacing in a medical device in response to ischemia

• US 20070203524A1
• Filed: 02/28/2006
• Published: 08/30/2007
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stylos, Lee, Sheldon, Todd, Combs, William, Lu, Steven, Nehls, Robert
• Granted Patent: US 7,848,808 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• 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 1/37 Monitoring; Protecting

Abstract

An implantable medical device system and method in which the implantable device is adapted to operate in a minimum ventricular pacing mode. The device delivers cardiac pacing pulses in a first pacing mode during a normal mode of operation and upon detecting myocardial ischemia alters the first pacing mode in response to the myocardial ischemia detection.

Claims

1. A method for delivering cardiac pacing in an implantable medical device, comprising:

delivering cardiac pacing pulses in a first pacing mode;

detecting myocardial ischemia; and

altering the first pacing mode in response to the myocardial ischemia detection.

2. The method of claim 1 wherein altering the first pacing mode includes switching from the first pacing mode to a second pacing mode.

3. The method of claim 1 wherein altering the first pacing mode includes measuring a time interval between an atrial event and an intrinsic ventricular event and switching from an atrial-only pacing mode to a ventricular pacing mode in response to the measured time interval crossing a predetermined limit.

4. The method of claim 1 wherein altering the first pacing mode includes altering a ventricular pacing configuration.

5. The method of claim 1 wherein altering the first pacing mode includes adjusting an atrial-ventricular (AV delay).

6. The method of claim 1 wherein altering the first pacing mode includes adjusting a maximum tracking rate.

7. The method of claim 1 wherein altering the first pacing mode includes adjusting a maximum sensor indicated rate.

8. The method of claim 1 wherein altering the first pacing mode includes:

overdrive pacing in an atrial chamber, detecting a loss of atrial-ventricular (AV) conduction in response to the overdrive pacing, and switching from an atrial-only pacing mode to a non-tracking ventricular pacing mode.

9. The method of claim 1 wherein altering the first pacing mode includes adjusting a programmed arrhythmia detection criterion in response to the ischemia detection.

10. The method of claim 1 wherein altering the first pacing mode includes adjusting a programmed tachycardia therapy in response to the ischemia detection.

11. The method of claim 1 wherein altering the first pacing mode includes any of adjusting a frequency of ischemia monitoring and adjusting a sampling rate of an ischemia monitoring signal.

12. The method of claim 1 further including detecting a sustained myocardial ischemia episode and altering the first response to provide a second response to the detecting a sustained myocardial ischemia episode.

13. The system of claim 1 wherein altering the first pacing mode includes altering the first pacing mode based on an operating status stored during a previous ischemia episode.

15. The system of claim 12 wherein the processor alters the first pacing mode by switching from the first pacing mode to a second pacing mode.

16. The system of claim 12 wherein the processor alters the first pacing mode by measuring a time interval between an atrial event and an intrinsic ventricular event and switches from an atrial-only pacing mode to a ventricular pacing mode in response to the measured time interval crossing a predetermined limit.

17. The system of claim 12 further comprising switching circuitry for selecting the plurality of electrodes and wherein the processor alters the first pacing mode by adjusting a pacing electrode configuration.

18. The system of claim 12 wherein the processor adjusts a timing interval.

19. The system of claim 12 wherein the processor adjusts a maximum tracking rate.

20. The system of claim 12 wherein the processor adjusts a maximum sensor indicated rate.

21. The system of claim 12 wherein the processor delivers overdrive pacing in an atrial chamber, detects a loss of atrial-ventricular (AV) conduction in response to the overdrive pacing, and switches from an atrial-only pacing mode to a non-tracking ventricular pacing mode.

22. The system of claim 12 wherein the processor adjusts a programmed tachycardia detection criterion in response to the means for detecting myocardial ischemia.

23. The system of claim 11 wherein the processor adjusts a programmed tachycardia therapy in response to the means for detecting myocardial ischemia.

24. The system of claim 1 wherein the processor adjusts any of a frequency of ischemia monitoring and a sampling rate of an ischemia monitoring signal.

25. The system of claim 1 wherein the processor alters the first response to provide a second response to the means for detecting myocardial ischemia in response to detecting a sustained myocardial ischemia episode.

26. The system of claim 1 wherein the processor alters the first pacing mode based on an operating status stored during a previous ischemia episode.

14. An implantable medical device system adapted to deliver cardiac pacing, comprising:

a plurality of electrodes;

an output circuit coupled to the plurality of electrodes for delivering cardiac pacing pulses;

means for detecting myocardial ischemia;

a control circuit for controlling the delivery of cardiac pacing pulses by the output circuit; and

a processor, coupled to the control circuit, for altering a first pacing mode to provide a first response to the means for detecting myocardial ischemia.

27. A computer readable medium for storing a set of instructions which when implemented in an implantable medical device system cause the system to perform a method, comprising:

delivering cardiac pacing pulses in a first pacing mode;

detecting myocardial ischemia; and

altering the first pacing mode in response to myocardial ischemia detection.