System and method for determining phsyiologic events during pacing mode operation

• US 7,856,269 B2
• Filed: 07/31/2006
• Issued: 12/21/2010
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stanslaski, Scott R., Sheldon, Todd J., Betzold, Robert A., Sweeney, Michael O., Hettrick, Douglas A.
• Primary Examiner(s): Layno; Carl H
• Assistant Examiner(s): Behringer; Luther G
• Application Number:
  US11/461,162
• Publication Number:
  US 20080027494A1
• Time in Patent Office: 1,604 Days
• Field of Search: 607/4, 607/9, 607/27, 607 17- 19, 600/518
• US Class Current: 607/17
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD

Abstract

An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Claims

1. A method of operating an implantable medical device (IMD) comprising:

operating the IMD according to a ventricular pacing protocol (VPP) wherein ventricular pacing is provided only in a cardiac cycle wherein the previous cardiac cycle is devoid of a sensed ventricular event;

employing the IMD to sense for ventricular events on a ventricular channel;

employing the IMD to sense for ventricular events on an alternative sensing mechanism of the IMD if a complete cardiac cycle transpires without a ventricular event sensed on the ventricular channel; and

delivering the ventricular pacing triggered by a determination of whether a signal is sensed on the alternate sensing mechanism.

2. The method of claim 1, wherein the alternative sensing mechanism is far field sensing.

3. The method of claim 1, wherein the alternative sensing mechanism is external to the IMD.

4. The method of claim 3, wherein the alternative sensing mechanism is an implantable loop recorder or a Holter monitor.

5. The method of claim 1, wherein sensing on an alternative mechanism occurs prior to delivery of a ventricular backup pace.

6. The method of claim 1, wherein sensing on an alternative mechanism includes collecting data during the complete cardiac cycle for review after delivery of a ventricular backup pace.

7. The method of claim 1, further comprising:

detecting a ventricular arrhythmia;

determining if a ventricular backup pace occurred within a predetermined number of cardiac cycles prior to the ventricular arrhythmia;

evaluating data sensed on the alternative mechanism to determine if a premature ventricular contraction (PVC) occurred in the previous cardiac cycle;

correlating the ventricular backup pace to the ventricular arrhythmia if a PVC occurred.

8. The method of claim 7, wherein the correlation causes the IMD to disable the VPP.

9. The method of claim 1, wherein the alternative mechanism evaluates data from a time period defined by a ventricular blanking period following an atrial pacing pulse.

10. An implantable medical device (IMD) comprising:

means for operating the IMD according to a ventricular pacing protocol (VPP) wherein ventricular pacing is provided only in a cardiac cycle wherein the previous cardiac cycle is devoid of a sensed ventricular event;

means for sensing for ventricular events on a ventricular channel; and

means for employing the IMD to sense for ventricular events on an alternative sensing mechanism if a complete cardiac cycle transpires without a ventricular event sensed on the ventricular channel; and

means for delivering the ventricular pacing triggered by a determination of whether a signal is sensed on the alternate sensing mechanism.

11. The IMD of claim 10, wherein the alternative sensing mechanism is far field sensing.

12. The IMD of claim 11, wherein sensing on an alternative mechanism occurs prior to delivery of a ventricular backup pace.

13. The IMD of claim 11, wherein sensing on an alternative mechanism includes collecting data during the complete cardiac cycle for review after delivery of a ventricular backup pace.

14. The IMD of claim 11, further comprising:

means for detecting a ventricular arrhythmia;

means for determining if a ventricular backup pace occurred within a predetermined number of cardiac cycles prior to the ventricular arrhythmia;

means for evaluating data sensed on the alternative mechanism to determine if a premature ventricular contraction (PVC) occurred in the previous cardiac cycle; and

means for correlating the ventricular backup pace to the ventricular arrhythmia if a PVC occurred.

15. The IMD of claim 14, wherein the correlation causes the IMD to disable the VPP.

16. An implantable medical device (IMD) comprising:

a processor;

a pulse generator coupled with the processor for selectively delivering atrial and ventricular pulses;

an atrial lead operatively coupled with the processor and the pulse generator;

a ventricular lead operatively coupled with the processor and the pulse generator so that cardiac events sensed by the atrial lead or ventricular lead are provided to the processor as data;

a ventricular pacing protocol (VPP) module coupled with the processor to control ventricular pacing and preclude ventricular pacing in any cardiac cycle where a ventricular event was sensed in an immediately prior cardiac cycle; and

an undersensed ventricular event module coupled with the processor that evaluates data collected from a source other than the ventricular lead if a complete cardiac cycle transpires without sensing a ventricular event by the ventricular lead.

17. The IMD of claim 16, wherein the undersensed ventricular event module inhibits the ventricular pace if the data indicates a ventricular event occurred.

18. The IMD of claim 16, wherein the source is far field sensing.

19. The IMD of claim 16, wherein the data includes ventricular data obtained during a ventricular blanking period for the ventricular lead following the delivery of an atrial pacing pulse.

20. The IMD of claim 16, wherein data collected from the undersensed ventricular event module is transmitted to an external device for evaluation.