Apparatus and method for pacing mode switching during atrial tachyarrhythmias

• US 8,391,974 B2
• Filed: 12/20/2010
• Issued: 03/05/2013
• Est. Priority Date: 05/21/1999
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stahmann, Jeffrey E., Kramer, Andrew P.
• Primary Examiner(s): Bertram, Eric D.
• Application Number:
  US12/973,059
• Publication Number:
  US 20110087303A1
• Time in Patent Office: 806 Days
• Field of Search: 607/14, 600/518
• US Class Current: 607/14
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3624 occurring in the atrium, i.e. atrial tachycardia
• 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 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

A method for operating a cardiac pacemaker in which the mode of operation of the pacemaker is altered in response to detecting an episode of atrial tachycardia. In accordance with the invention, the pacemaker'"'"'s pacing mode is altered in a manner that attempts to maintain hemodynamic stability during the atrial tachycardia. Such a mode switch is particularly applicable to pacemaker patients suffering from some degree of congestive heart failure.

Claims

1. A cardiac pacemaker, comprising:

sensing amplifiers for sensing atrial and ventricular depolarizations;

pulse generators for delivering paces to the right and left ventricles;

a controller for controlling the delivery of paces in accordance with a primary pacing mode that delivers paces to only one ventricle;

wherein the controller is configured to switch the pacemaker to an atrial fibrillation pacing mode upon detection of an atrial tachyarrhythmia, wherein the atrial fibrillation pacing mode includes a biventricular pacing mode that delivers paces to both left and right ventricles in a non-atrial triggered pacing mode in which the controller adjusts a ventricular escape interval in order to regularize the rate at which ventricular beats occur by increasing the ventricular escape interval after a ventricular pace is delivered and decreasing the ventricular escape interval after a ventricular sense.

2. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is based on a previous value of the ventricular escape interval and a measured intrinsic ventricular rate.

3. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed by increasing the ventricular escape interval after a ventricular pace is delivered and decreasing the ventricular escape interval after a ventricular sense by computing a weighted average of a previous value of the ventricular escape interval and an RR interval, where the RR interval is the interval between the ventricular sense and the preceding ventricular sense or pace.

4. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed by increasing the ventricular escape interval after a ventricular pace is delivered by an amount depending upon a previous value of the ventricular escape interval.

5. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed by increasing the ventricular escape interval after a ventricular pace is delivered by multiplying a previous value of the ventricular escape interval by a specified coefficient.

6. The pacemaker of claim 1 wherein the biventricular pacing mode delivers paces to both ventricles with a selected biventricular offset interval.

7. The pacemaker of claim 1 wherein the biventricular pacing mode is a biventricular triggered mode.

8. The pacemaker of claim 1 wherein the atrial fibrillation pacing mode includes adjustments to one or more rate-adaptive pacing parameters.

9. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed on a beat-to-beat basis.

10. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed periodically.

11. The pacemaker of claim 1 wherein the adjustment of the ventricular escape interval is performed based upon an average of successive R-R intervals.

12. The pacemaker of claim 1 wherein, in the atrial fibrillation pacing mode, the ventricular escape interval is increased after each ventricular pace is delivered and after each ventricular sense.