Method and apparatus for diagnosis and treatment of arrhythmias

• US 5,893,882 A
• Filed: 12/17/1996
• Issued: 04/13/1999
• Est. Priority Date: 12/17/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Peterson, David K., Jirak, Thomas L., Zhou, Ren, Hill, Michael R. S.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US08/767,657
• Time in Patent Office: 847 Days
• Field of Search: 607/9, 607/14
• US Class Current: 607/14
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD

Abstract

A pacemaker provided with a mode switching feature adapted to stabilize ventricular heart rate during atrial fibrillation. In a preferred embodiment of the invention, the device nominally operates in an atrial synchronized pacing mode such as DDD, DDDR, VDD or VDDR. In response to detection of atrial rhythm characteristics consistent with atrial fibrillation, the device switches into a non-atrial synchronized, ventricular rate stabilization pacing mode with the base ventricular pacing rate modulated on a beat by beat basis based upon preceding intrinsic or paced ventricular heartbeat intervals to adjust the pacing interval towards a desired preset rate stabilization target pacing interval which is typically less than the programmed base pacing interval of the device. While the ventricular rate stabilization mode is in effect, the current pacing interval is set equal to the preceding intrinsic or paced interval, with an increment if the preceding interval is less than the desired or target pacing interval, as typically will be the case, or with a decrement if the preceding interval is greater than the desired pacing interval. In a preferred embodiment of the invention, the device paces both the atria and ventricles in a DDI rate stabilization pacing mode with the ventricular pacing interval being modulated.

Claims

1. A pacemaker, comprising:

means for detecting heart rhythms consistent with supraventricular tachyarrhythmia;

a ventricular pacing pulse generator;

means responsive to detection of said heart rhythms for initiating operation of said ventricular pacing pulse generator in a ventricular rate stabilization pacing mode, further comprising means for defining a desired ventricular pacing interval and means for modulating ventricular pacing intervals on a beat by beat basis by deriving pacing intervals based upon directly preceding intrinsic heartbeat intervals and pacing intervals, incremented to approach said desired pacing interval.

2. A pacemaker according to claim 1 wherein said modulating means further comprises means for deriving pacing intervals based upon directly preceding intrinsic heartbeat intervals, decremented to approach said desired pacing interval.

3. A pacemaker according to claim 1 wherein said responsive means comprises means for continuing operation of said ventricular pacing pulse generator in said ventricular rate stabilization pacing mode for a predefined period of time following failure of said detecting means to detect heart rhythms consistent with supraventricular tachyarrhythmia.

4. A pacemaker according to claim 3 further comprising means for defining a nominal pacing interval greater than said desired interval and wherein said responsive means further comprises means responsive to expiration of said predefined period of time for initiating for causing said ventricular pacing pulse generator to increment said pacing intervals on a beat by beat basis toward said nominal pacing rate.

5. A pacemaker according to any of claims 1-4 wherein said detecting means comprises means for detecting atrial depolarizations and said pacemaker further comprises means for operating said ventricular pacing pulse generator in a nominal mode in which said ventricular pacing pulses are generated synchronized to detected atrial depolarizations and wherein said responsive means comprises means for initiating operation of said ventricular pacing pulse generator in a non-atrial synchronized ventricular rate stabilization pacing mode.

6. A pacemaker, comprising:

means for detecting heart rhythms consistent with supraventricular tachyarrhythmia;

a ventricular pacing pulse generator;

means responsive to detection of said heart rhythms for initiating operation of said ventricular pacing pulse generator in a ventricular rate stabilization pacing mode, further comprising means for defining a desired ventricular pacing interval and means for modulating ventricular pacing intervals on a beat by beat basis by deriving ventricular pacing intervals by measuring preceding intrinsic heartbeat intervals and incrementing the measured intrinsic heartbeat intervals to approach said desired pacing interval.

7. A pacemaker according to claim 6 wherein said modulating means further comprises means for modulating ventricular pacing intervals on a beat by beat basis by deriving ventricular pacing intervals by measuring preceding intrinsic heartbeat intervals and decrementing the measured intrinsic heartbeat intervals to approach said desired pacing interval.

8. A pacemaker according to claim 7 wherein said modulating means comprises means for deriving ventricular pacing intervals by decrementing immediately preceding measured intrinsic heartbeat intervals.

9. A pacemaker according to claim 6 or claim 7 wherein said modulating means comprises means for deriving ventricular pacing intervals by incrementing immediately preceding measured intrinsic heartbeat intervals.

10. A pacemaker according to claim 6 wherein said responsive means comprises means for continuing operation of said ventricular pacing pulse generator in said ventricular rate stabilization pacing mode for a predefined period of time following failure of said detecting means to detect heart rhythms consistent with supraventricular tachyarrhythmia.

11. A pacemaker according to claim 10 further comprising means for defining a nominal pacing interval greater than said desired interval and wherein said responsive means further comprises means responsive to expiration of said predefined period of time for initiating for causing said ventricular pacing pulse generator to increment said pacing intervals on a beat by beat basis toward said nominal pacing rate.

12. A pacemaker according to any of claim 6 or claim 7 or claim 10 or claim 11 wherein said detecting means comprises means for detecting atrial depolarizations and said pacemaker further comprises means for operating said ventricular pacing pulse generator in a nominal mode in which said ventricular pacing pulses are generated synchronized to detected atrial depolarizations and wherein said responsive means comprises means for initiating operation of said ventricular pacing pulse generator in a non-atrial synchronized ventricular rate stabilization pacing mode.