Cardiac pacemaker with pacing rate monitoring

• US 8,364,261 B2
• Filed: 11/01/2010
• Issued: 01/29/2013
• Est. Priority Date: 12/22/2005
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stubbs, Scott, Sowder, Conrad L., Linder, William J., Elliott, Lynn S., Hoyme, Kenneth P., Doshi, Hiten J.
• Primary Examiner(s): Gedeon, Brian T
• Application Number:
  US12/916,881
• Publication Number:
  US 20110046689A1
• Time in Patent Office: 820 Days
• Field of Search: 607/9, 600/508, 600/509
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/3931 Protecting, e.g. back-up systems

Abstract

A pacing monitoring system is described for incorporation in an implantable pacemaker that monitors the pacing rate and/or cumulative pace count in order to protect a patient from excessive pacing. The system includes monitoring circuitry that is configured to operate in multiple monitoring zones, where each zone is adapted to prevent excessively high-rate pacing during a particular mode of device operation.

Claims

1. A method for operating a cardiac rhythm management device, comprising:

scheduling paces to be delivered by pacing circuitry in accordance with a programmed pacing mode;

measuring the interval between the times of a scheduled pace and a preceding delivered pace, the reciprocal of the interval being the pacing rate;

counting the number of pacing pulses delivered over a specified time period and deriving a pace count therefrom;

monitoring the pacing rate and the pace count in either a normal-rate zone or a high-rate zone;

when operating in the normal-rate zone, setting an error flag if the pacing rate exceeds a specified normal-rate limit value; and

,

when operating in the high-rate zone, setting an error flag if either the pacing rate exceeds a specified high-rate limit value or if the pace count over the specified period of time exceeds a specified count limit value.

2. The method of claim 1 further comprising blocking delivery of a scheduled pace that would exceed the normal-rate limit value.

3. The method of claim 1 further comprising blocking delivery of a scheduled pace that would exceed the high-rate limit value.

4. The method of claim 1 further comprising blocking delivery of a scheduled pace that would exceed the count limit value.

5. The method of claim 1 further comprising blocking delivery of a scheduled pace that results in the setting of an error flag.

6. The method of claim 1 further comprising operating in the normal-rate zone if pacing is being delivered in a bradycardia pacing mode.

7. The method of claim 1 further comprising operating in the high-rate zone if the pacing is being delivered in an anti-tachycardia pacing mode

8. The method of claim 1 further comprising:

delivering atrial and ventricular pacing pulses in accordance with a programmed pacing mode;

measuring the interval between the times of a scheduled pace and a preceding delivered pace for both atrial and ventricular paces, the reciprocal of the intervals being the atrial pacing rate and the ventricular pacing rate;

counting the number of atrial and ventricular pacing pulses delivered over a specified time period and derive a total pace count therefrom;

operating in either an atrial high-rate zone and a ventricular normal-rate zone or a ventricular high-rate zone and an atrial normal-rate zone;

when operating in the atrial high-rate zone, setting an error flag if the atrial pacing rate exceeds a specified atrial high-rate limit value; and

,

when operating in the ventricular high-rate zone, setting an error flag if the ventricular pacing rate exceeds a specified ventricular high-rate limit value.

9. The method of claim 8 further comprising, when operating in the atrial high-rate zone, setting an error flag if the pace count over the specified period of time exceeds the specified count limit value.

10. The method of claim 8 further comprising, when operating in the ventricular high-rate zone, setting an error flag if the total pace count over the specified period of time exceeds the specified count limit value.

11. The method of claim 8 further comprising blocking delivery of a scheduled pace that would exceed the normal-rate limit value, the atrial high-rate limit value, the ventricular high-rate limit value, or the specified count limit value and that results in the setting of an error flag.

12. The method of claim 8 further comprising operating in the normal-rate zone if pacing is being delivered in a bradycardia pacing mode and operating in the atrial high-rate zone if the pacing is being delivered in an atrial anti-tachycardia pacing mode and in the ventricular high-rate zone if the pacing is being delivered in a ventricular anti-tachycardia pacing mode.

13. The method of claim 1 further comprising operating in a fail-safe zone having a specified fail-safe rate limit value, wherein the fail-safe zone is transitioned to when an error flag is set, and preventing scheduled paces from being delivered above the specified fail-safe rate limit value if the fail-safe rate zone is in operation.

14. The method of claim 13 further comprising operating in an unlimited-rate zone in which no rate limit values or count limit values are imposed.

15. The method of claim 14 further comprising:

entering the unlimited-rate zone upon receiving an unlimited-rate zone command via telemetry and remaining in the unlimited-rate zone for a specified test duration; and

,

setting an error flag after the specified test duration expires and then reverting to the fail-safe zone.

16. The method of claim 14 further comprising remaining in the unlimited-rate zone for as long as an unlimited-rate command is continually received up to a specified clinical duration that is greater than the specified test duration.

17. The method of claim 14 further comprising transitioning to any of the normal-rate, high-rate, unlimited-rate, or fail-safe zones upon receipt of a zone select transition command via telemetry.

18. The method of claim 1 further comprising permitting, without setting an error flag, delivery of a single pace during a specified grace interval after the preceding pace without regard to the specified rate limit value when in the normal-rate zone.

19. The method of claim 1 further comprising entering the high-rate zone upon receiving a high-rate zone command via telemetry.

20. The method of claim 1 further comprising:

delivering pacing pulses to first and second heart chambers in accordance with a programmed pacing mode;

measuring the interval between the times of a scheduled pace and a preceding delivered pace for both first chamber and second chamber paces, the reciprocal of the intervals being the first chamber pacing rate and the second chamber pacing rate;

counting the number of first chamber and second chamber pacing pulses delivered over a specified time period and derive a total pace count therefrom; and

,

operating in either a normal-rate zone or a high-rate zone for both of the first and second chambers.