Device and method for providing atrial-synchronized ventricular pacing with selective atrial tracking

• US 20060247690A1
• Filed: 04/27/2005
• Published: 11/02/2006
• Est. Priority Date: 04/27/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hess, Michael F., Warman, Eduardo N.
• Granted Patent: US 8,332,030 B2
• Time in Patent Office: Days
• 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 1/3627 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

Abstract

A device for delivering pacing therapy includes an atrial and ventricular leads, sensing circuitry connected to the leads for detecting depolarizations, and pulse generation circuitry for delivering ventricular pacing pulses based on sensed atrial depolarizations. The device includes control circuitry for controlling the pulse generation circuitry in a first mode in which the pulse generation circuitry delivers atrial synchronized pulses to both the right and left ventricular leads in response to each atrial depolarization sensed. In response to a detected atrial arrhythmia, the control circuitry causes the pulse generation circuitry to deliver atrial synchronized ventricular pacing pulses in response only to selected atrial depolarizations.

Claims

1. A device for providing pacing therapy, the device comprising:

an atrial lead for sensing electrical activity in an atrium;

a ventricular lead for sensing electrical activity in a ventricle and for delivering electrical pulses to the ventricle;

sensing circuitry connected to the atrial and ventricular leads for sensing depolarizations in the atrium and ventricle, respectively;

pulse generation circuitry connected to the ventricular lead for delivering pacing pulses to the ventricle, respectively; and

control circuitry for controlling the pulse generation circuitry in a mode in which the pulse generation circuitry delivers atrial synchronized pulses to the ventricular lead in response to each atrial depolarization and causing the pulse generation circuitry, in response to a detected atrial arrhythmia, to deliver an atrial synchronized pacing pulse to the ventricular lead in response only to selected atrial depolarizations.

2. The device of claim 1, wherein the control circuitry determines whether the detected atrial arrhythmia meets a regularity criteria.

3. The device of claim 1, further including an activity sensor, wherein the control circuitry causes the pulse generation circuitry to deliver atrial synchronized pulses to the ventricle at a rate that maintains a ventricular beat rate closest to a preferred beat rate determined by the activity sensor.

4. The device of claim 1, wherein the control circuitry determines a desired ratio of atrial depolarizations to ventricular paced pulses based on a beat rate of the atrial arrhythmia and a preferred ventricular beat rate and causes the pulse generation circuitry to deliver atrial synchronized pulses to the ventricular lead in response to detection of a number of atrial depolarizations corresponding to the desired ratio.

5. The device of claim 4, wherein if the desired ratio of atrial depolarizations to ventricular paced pulses is determined to be N-to-one, where N is an integer, then the control circuitry causes the pulse generation circuitry to deliver the atrial synchronized pulse to the ventricular lead in response to each Nth atrial depolarization detected.

6. The device of claim 1, wherein the control circuitry determines a desired ventricular pace rate, and applies an atrial refractory period corresponding with the desired ventricular pace rate after each atrial synchronized ventricular pacing pulse that prevents delivery of another atrial synchronized ventricular pacing pulse until the refractory period has ended.

7. The device of claim 1, wherein during the mode in which the pulse generation circuitry delivers atrial synchronized pulses to the ventricular lead in response to each atrial depolarization, atrial synchronized pulses are provided to the ventricular lead at a first time interval following each atrial depolarization, and wherein in response to the detected atrial arrhythmia, the control circuitry causes the pulse generation circuitry to deliver the atrial synchronized pacing pulse to the ventricular lead in response only to selected atrial depolarizations, the atrial synchronized pacing pulse is provided to the ventricular lead at a second time interval following selected atrial depolarizations.

8. The device of claim 7, wherein the second time interval is different from the first time interval.

9. A method for providing pacing therapy, the method comprising:

delivering ventricular pulses in a mode wherein each atrial depolarization results in delivery of an atrial synchronized ventricular pulse;

detecting an atrial arrhythmia; and

switching to ventricular pacing in which only selected atrial depolarizations result in delivery of an atrial synchronized ventricular pulse.

10. The method of claim 9, further including:

measuring the atrial arrhythmia to determine an atrial beat rate;

determining a target ventricular beat rate;

determining a pacing ratio between the atrial beat rate and the target ventricular beat rate; and

delivering atrial synchronized ventricular pulses corresponding to the pacing ratio such that the atrial synchronized ventricular pulses are provided after sensing a number of atrial depolarizations.

11. The method of claim 10, wherein if the pacing ratio is selected to be N to one, wherein N is an integer, then following each Nth sensed atrial depolarization an atrial synchronized ventricular pulse is delivered.

12. The method of claim 9, further including:

determining a target ventricular beat rate for delivering atrial synchronized ventricular pulses;

determining a ventricular refractory period based on the target ventricular beat rate; and

delivering a first atrial synchronized ventricular pacing pulse followed by a first atrial refractory period in which sensed atrial depolarizations do not result in delivery of ventricular pacing pulses; and

delivering a second atrial synchronized ventricular pacing pulse following the next atrial depolarization sensed after the first atrial refractory period has ended, followed by a second atrial refractory period in which sensed atrial depolarizations do not result in delivery of ventricular pacing pulses.

13. The method of claim 9, further including detecting whether the atrial arrhythmia is regular or irregular, wherein if the atrial arrhythmia is regular then switching to ventricular pacing in which only selected atrial depolarizations result in delivery of an atrial synchronized ventricular pulse.

14. The method of claim 9, wherein delivering ventricular pulses in a mode wherein each atrial depolarization results in delivery of an atrial synchronized ventricular pulse further includes providing a first time interval between each atrial depolarization and the atrial synchronized ventricular pulse;

and wherein switching to ventricular pacing in which only selected atrial depolarizations result in delivery of an atrial synchronized ventricular pulse further includes providing a second time interval between each selected atrial depolarization and delivery of the atrial synchronized ventricular pulse.

15. The method of claim 14, wherein the second time interval is different from the first time interval.

16. A device for providing pacing therapy, the device comprising:

an atrial lead for sensing electrical activity in an atrium;

a right ventricular lead for sensing electrical activity in a right ventricle and for delivering electrical pulses to the right ventricle;

a left ventricular lead for sensing electrical activity in a left ventricle and for delivering electrical pulses to the left ventricle;

sensing circuitry connected to the atrial, right ventricular and left ventricular leads for sensing atrial and ventricular depolarizations;

pulse generation circuitry connected to the right ventricular and left ventricular leads for delivering pacing pulses to the right ventricle and left ventricle, respectively; and

control circuitry for controlling the pulse generation circuitry in a mode in which the pulse generation circuitry delivers atrial synchronized pulses to both the right and left ventricular leads in response to each atrial depolarization and causing the pulse generation circuitry, in response to a detected atrial arrhythmia, to deliver an atrial synchronized pacing pulses to both the right and left ventricular leads in response only to selected atrial depolarizations.

17. The device of claim 16, further including an activity sensor, wherein the control circuitry causes the pulse generation circuitry to deliver atrial synchronized pulses to the right and left ventricles at a rate that maintains a ventricular beat rate closest to a preferred beat rate determined by the activity sensor.

18. The device of claim 16, wherein the control circuitry determines a desired ratio of atrial depolarizations to ventricular paced pulses based on a beat rate of the atrial arrhythmia and a preferred ventricular beat rate and causes the pulse generation circuitry to deliver atrial synchronized pulses to the right and left ventricular leads in response to detection of a number of atrial depolarizations corresponding to the desired ratio.

19. The device of claim 18, wherein if the desired ratio of atrial depolarizations to ventricular paced pulses is determined to be N-to-one, where N is an integer, then the control circuitry causes the pulse generation circuitry to deliver the atrial synchronized pulse to the right and left ventricular leads in response to each Nth atrial depolarization sensed.

20. The device of claim 16, wherein the control circuitry determines a desired ventricular pace rate, and applies an atrial refractory period corresponding with the desired ventricular pace rate after each atrial synchronized ventricular pacing pulse that prevents delivery of another atrial synchronized ventricular pacing pulse until the atrial refractory period has ended.