Reduction of left-ventricular offset interaction with tachyarrhythmia detection

• US 6,757,562 B2
• Filed: 10/25/2001
• Issued: 06/29/2004
• Est. Priority Date: 10/25/2001
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Perschbacher, David L., Stahmann, Jeffrey E., Kramer, Andrew P., Baker, Kenneth L.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/037,444
• Publication Number:
  US 20030083704A1
• Time in Patent Office: 978 Days
• Field of Search: 607/4, 607/5, 607/9, 607/14
• US Class Current: 607/14
• 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 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

A device and method for improving tachyarrhythmia detection when the ventricles are resynchronized by delivering paces to both ventricles separated by a specified offset interval. Timing of escape intervals and tachyarrhythmia detection is based upon senses from one of the ventricles designated as a rate ventricle. A reversion pacing mode is provided in order to prevent tachyarrhythmia detection from being compromised when the rate ventricle is paced after the other ventricle.

Claims

1. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

inhibit a synchronized chamber pace at the pacing instant defined by the negative offset interval and deliver a pace to at least one of the chambers upon expiration of the escape interval when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.

2. The device of claim 1 wherein the specified limit value is the specified tachyarrhythmia rate threshold interval plus a specified safety margin.

3. The device of claim 1 wherein the controller is programmed to deliver the synchronized chamber pace at the expiration of the escape interval, with a pace being simultaneously delivered to the rate chamber with the synchronized chamber pace, whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

4. The device of claim 1 wherein the controller is programmed to deliver the synchronized chamber pace at the expiration of the escape interval, with no pace being delivered to the rate chamber with the synchronized chamber pace, whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

5. The device of claim 1 wherein the controller is programmed to deliver no pace to the synchronized chamber and pace only the rate chamber upon expiration of the escape interval whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

6. The device of claim 1 wherein the controller is programmed to deliver a synchronized chamber pace before expiration of the escape interval and at a time interval measured from an immediately preceding rate chamber sense or pace equal to the specified tachyarrhythmia rate threshold interval whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

7. The device of claim 1 wherein the rate and synchronized chambers are the ventricles and wherein the controller is programmed to pace the rate and synchronized ventricles in accordance with a ventricular demand pacing mode such that the escape interval is a ventricular escape interval.

8. The device of claim 7 further comprising an exertion level sensor wherein the controller is programmed to modulate the ventricular escape interval in accordance with input from the exertion level sensor.

9. The device of claim 1 further comprising an atrial sensing channel and wherein the controller is programmed to pace the ventricles in accordance with an atrial tracking mode such the escape interval is an atrio-ventricular interval.

10. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

decrease the negative offset interval to a value that is equal to or less than the pacing interval minus the specified tachyarrhythmia rate threshold interval when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.

11. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

vary the negative offset from a maximum specified value to a minimum specified value as the pacing rate, defined as the reciprocal of the pacing interval, varies from a specified minimum value to the specified maximum pacing rate.

12. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

limit the specified maximum pacing rate that the device will allow to be programmed, once the specified tachyarrhythmia rate threshold is programmed, to be equal to or less than the reciprocal of the specified tachyarrhythmia rate threshold interval plus the negative offset interval.

13. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

modify a criteria for recognizing a tachyarrhythmia so as to require a lower proportion of successive detected ventricular depolarizations when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.

14. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

interchange the heart chambers designated as rate and synchronized chambers when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.

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

sensing rate and synchronized heart chambers through separate channels and generating sense signals upon detection of an intrinsic depolarization occurring in a chamber;

detecting a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval;

pacing the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the time interval from an immediately preceding rate chamber sense or pace to expiration of the escape interval, is constrained to be no shorter than the specified tachyarrhythmia rate threshold interval;

rendering the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

inhibiting a synchronized chamber pace at the pacing instant defined by the negative offset interval and delivering a pace to at least one of the chambers upon expiration of the escape interval when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.

16. The method of claim 15 wherein the specified limit value is the specified tachyarrhythmia rate threshold interval plus a specified safety margin.

17. The method claim of 15 further comprising delivering the synchronized chamber pace at the expiration of the escape interval, with a pace being simultaneously delivered to the rate chamber with the synchronized chamber pace, whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

18. The method of claim of 15 further comprising delivering the synchronized chamber pace at the expiration of the escape interval, with no pace being delivered to the rate chamber with the synchronized chamber pace, whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

19. The method claim of 15 further comprising delivering no pace to the synchronized chamber and pace only the rate chamber upon expiration of the escape interval whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

20. The method claim of 15 further comprising delivering a synchronized chamber pace before expiration of the escape interval and at a time interval measured from an immediately preceding rate chamber sense or pace equal to the specified tachyarrhythmia rate threshold interval whenever the synchronized chamber pace is inhibited at the pacing instant defined by the negative offset interval.

21. The method of claim 15 wherein the rate and synchronized chambers are the right and left ventricles, respectively.

22. The method of claim 21 wherein the rate and synchronized chambers are the ventricles and further comprising pacing the rate and synchronized ventricles in accordance with a ventricular demand pacing mode such that the escape interval is a ventricular escape interval.

23. The method of claim 22 further comprising modulating the ventricular escape interval in accordance with input from an exertion level sensor.

24. The method of claim 21 further comprising pacing the ventricles in accordance with an atrial tracking mode such the escape interval is an atrio-ventricular interval.

25. A cardiac rhythm management device, comprising:

sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber;

a controller for controlling the delivery of paces in accordance with a programmed pacing mode;

wherein the controller is programmed to;

detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified first tachyarrhythmia rate threshold interval;

pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified first tachyarrhythmia rate threshold interval;

render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and

,

increasing the pacing interval to be equal to or greater than a specified second tachyarrhythmia rate threshold interval plus the negative offset interval when an interval between a sense or pace and a subsequent sense is below the specified first tachyarrhythmia rate threshold interval.