System providing ventricular pacing and biventricular coordination

• US 8,135,465 B2
• Filed: 12/01/2008
• Issued: 03/13/2012
• Est. Priority Date: 05/21/1999
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Krig, David B., Hartley, Jesse W., Stahl, Wyatt, Stahmann, Jeffrey E.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US12/325,887
• Publication Number:
  US 20090076563A1
• Time in Patent Office: 1,198 Days
• Field of Search: 607/9, 607/14
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

A cardiac rhythm management system includes techniques for computing an indicated pacing interval, AV delay, or other timing interval. In one embodiment, a variable indicated pacing interval is computed based at least in part on an underlying intrinsic heart rate. The indicated pacing interval is used to time the delivery of biventricular coordination therapy even when ventricular heart rates are irregular, such as in the presence of atrial fibrillation. In another embodiment, a variable filter indicated AV interval is computed based at least in part on an underlying intrinsic AV interval. The indicated AV interval is used to time the delivery of atrial tracking biventricular coordination therapy when atrial heart rhythms are not arrhythmic. Other indicated timing intervals may be similarly determined. The indicated pacing interval, AV delay, or other timing interval can also be used in combination with a sensor indicated rate indicator.

Claims

1. A method for operating a cardiac pacemaker, comprising:

sensing a ventricle;

pacing a ventricle upon expiration of an atrio-ventricular escape interval initiated by an atrial event and stopped by a ventricular sense;

measuring an intrinsic atrio-ventricular interval as the time between the atrial event and the ventricular sense during a cardiac cycle when no ventricular pace is delivered;

after the cardiac cycle when no ventricular pace is delivered, decreasing the atrio-ventricular escape interval in a manner dependent upon the measured intrinsic atrio-ventricular interval as a mathematical function thereof, wherein the atrio-ventricular escape interval is decreased by computing a weighted average of the atrio-ventricular escape interval and the measured intrinsic atrio-ventricular interval multiplied by a scaling factor; and

,

after a cardiac cycle when a ventricular pace is delivered, increasing the atrio-ventricular escape interval.

2. The method of claim 1, wherein the atrial event initiating the atrio-ventricular escape interval is an atrial pace.

3. The method of claim 1, wherein the atrial event initiating the atrio-ventricular escape interval is an atrial sense.

4. The method of claim 1, wherein the atrio-ventricular escape interval is decreased in accordance with the measured intrinsic atrio-ventricular interval after each ventricular sense.

5. The method of claim 1, wherein the atrio-ventricular escape interval is increased after each ventricular pace by multiplying the atrio-ventricular escape interval by a specified filter coefficient.

6. A cardiac pacing device, comprising:

sensing circuits for sensing depolarizations in a ventricle and an atrium;

a pacing circuit for delivering pacing pulses to the ventricle;

a controller for controlling the delivery of paces such that the ventricle is paced upon expiration of an atrio-ventricular escape interval initiated by an atrial event and stopped by a ventricular sense;

wherein the controller is further programmed to;

measure an intrinsic atrio-ventricular interval as the time between the atrial event and the ventricular sense during a cardiac cycle when no ventricular pace is delivered;

after the cardiac cycle when no ventricular pace is delivered, decrease the atrio-ventricular escape interval in a manner dependent upon the measured intrinsic atrio-ventricular interval as a mathematical function thereof, wherein the atrio-ventricular escape interval is decreased by computing a weighted average of the atrio-ventricular escape interval and the measured intrinsic atrio-ventricular interval multiplied by a scaling factor; and

,

after a cardiac cycle when a ventricular pace is delivered, increase the atrio-ventricular escape interval.

7. The device of claim 6, wherein the controller is further programmed such that the atrial event initiating the atrio-ventricular escape interval is an atrial pace.

8. The device of claim 6, wherein the controller is further programmed such that the atrial event initiating the atrio-ventricular escape interval is an atrial sense.

9. The device of claim 6, wherein the controller is further programmed such that the atrio-ventricular escape interval is decreased in accordance with the measured intrinsic atrio-ventricular interval after each ventricular sense.

10. The device of claim 6, wherein the controller is further programmed such that the atrio-ventricular escape interval is increased after each ventricular pace by multiplying the atrio-ventricular escape interval by a specified filter coefficient.