Rate Smoothing Pacing Modality with Increased Ventricular Sensing

• US 20080027492A1
• Filed: 07/31/2006
• Published: 01/31/2008
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hettrick, Douglas A., Belk, Paul A., Sheldon, Todd J., Betzold, Robert A., Sweeney, Michael O., Stanslaski, Scott R.
• Granted Patent: US 7,502,647 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence

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 comprising:

operating an implantable medical device (IMD) according to a ventricular pacing protocol (VPP) wherein a sensed ventricular event in a first cardiac cycle precludes cardiac pacing in a second cardiac cycle immediately subsequent to the first cardiac cycle;

initiating a first post atrial ventricular blanking (PAVB) interval following an atrial pacing pulse under a first condition;

accelerating the first cardiac cycle by delivering a second atrial pacing pulse to terminate the first cardiac cycle early in response to a first sensed indicator; and

initiating a second PAVB following the atrial pacing pulse under a second condition, wherein the first PAVB is shorter in duration than the second PAVB.

2. The method of claim 1, wherein the first condition is when a ventricular pacing pulse has not been provided within a first predetermined interval prior to the atrial pacing and the second condition is when a ventricular pacing pulse has been provided within the first predetermined interval prior to the atrial pacing pulse.

3. The method of claim 2, wherein the first sensed indicator is a premature ventricular contraction (PVC).

4. The method of claim 2, wherein the first sensed indicator is an expiration of an AV interval timer.

5. The method of claim 4, further comprising:

initiating the second cardiac cycle with delivery of the second atrial pacing pulse so that ventricular pacing is permitted in the second cardiac cycle; and

initiating a paced AV (PAV) interval timer having a duration expected to permit intrinsic conduction to occur and to deliver a ventricular pacing pulse upon termination of the PAV if no ventricular event has been sensed prior to termination of the PAV.

6. The method of claim 3, further comprising:

modifying atrial interval timing over a plurality of cardiac cycles to return a heart rate to a pre-acceleration rate.

7. The method of claim 3, further comprising:

delaying the second atrial pacing pulse by a predetermined amount if an intrinsic atrial depolarization is sensed.

8. The method of claim 4, further comprising:

modifying atrial interval timing over a plurality of cardiac cycles to return a heart rate to a pre-acceleration rate.

9. The method of claim 2, further comprising:

providing a crosstalk window having a duration that expires at the end of a predetermined interval following either the first PAVB or the second PAVB.

10. The method of claim 2, further comprising:

providing a crosstalk window having a duration that expires at the end of a predetermined interval following the atrial pacing pulse.

11. An implantable medical device (IMD) comprising:

a processor;

a pulse generator in communication with the processor for selectively providing cardiac pacing stimuli;

a lead system operably coupled to the pulse generator and the processor to deliver the cardiac pacing stimuli and to sense electrical signals representative of cardiac data;

a ventricular pacing protocol (VPP) module operably coupled to the processor and configured to receive data indicative of a sensed ventricular event in a first cardiac cycle and to preclude cardiac pacing in a second cardiac cycle immediately subsequent to the first cardiac cycle;

a pacing control module coupled with the processor and configured to initiate a first post atrial ventricular blanking period (PAVB) following an atrial pacing pulse if a first condition is met and initiate a second PAVB, longer in duration than the first PAVB, if a second condition is met; and

a VPP rate smoothing module configured to deliver a second atrial pacing pulse following the first PAVB to terminate a current cardiac cycle early in response to a first sensed indicator.

12. The IMD of claim 11, wherein the first condition is when a ventricular pacing pulse has not been provided within a first predetermined interval prior to the atrial pacing and the second condition is when a ventricular pacing pulse has been provided within the first predetermined interval prior to the atrial pacing pulse.

13. The IMD of claim 12 wherein the first sensed indicator is a premature ventricular contraction (PVC).

14. The IMD of claim 12 wherein the first sensed indicator is an expiration of an AV interval timer.

15. The IMD of claim 12 modifying atrial interval timing over a plurality of cardiac cycles to return a heart rate to a pre-acceleration rate.

16. The IMD of claim 11, wherein the first PAVB is about 8.5 ms and the second PAVB is about 30 ms.

17. The IMD of claim 12, further comprising:

a polarization module configured to measure polarization artifacts at a ventricular lead electrode interface, wherein the first PAVB is set to a value greater than a decay time of the polarization artifact.

18. An implantable medical device comprising:

means for operating the IMD according to a ventricular pacing protocol (VPP) wherein a sensed ventricular event in a first cardiac cycle precludes cardiac pacing in a second cardiac cycle immediately subsequent to the first cardiac cycle;

means for initiating a first post atrial ventricular blanking (PAVB) interval following a first atrial pacing pulse under a first condition;

means for accelerating the first cardiac cycle by delivering a second atrial pacing pulse to terminate the first cardiac cycle early in response to a first sensed indicator; and

means for initiating a second PAVB following the first atrial pacing pulse under a second condition, wherein the first PAVB is shorter in duration than the second PAVB.

19. The IMD of claim 18, wherein the first condition is when a ventricular pacing pulse has not been provided within a first predetermined interval prior to the atrial pacing and the second condition is when a ventricular pacing pulse has been provided within the first predetermined interval prior to the atrial pacing pulse.

20. The IMD of claim 19, wherein the first sensed indicator is a premature ventricular contraction (PVC).

21. The IMD of claim 19, wherein the first sensed indicator is an expiration of an AV interval timer.

22. The IMD of claim 19, further comprising:

means for initiating the second cardiac cycle with delivery of the second atrial pacing pulse so that ventricular pacing is permitted in the second cardiac cycle; and

means for initiating a paced AV (PAV) interval timer having a duration expected to permit intrinsic conduction to occur and to deliver a ventricular pacing pulse upon termination of the PAV if no ventricular event has been sensed prior to termination of the PAV.