Atrial retrograde management

• US 20060129199A1
• Filed: 12/15/2004
• Published: 06/15/2006
• Est. Priority Date: 12/15/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Geng, Garg, Ankur
• Granted Patent: US 8,229,561 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold
• CPC Class Codes: A61N 1/3714 Atrial capture

Abstract

Methods and systems for classifying cardiac responses to pacing stimulation and/or preventing retrograde cardiac conduction are described. Following delivery of a pacing pulse to an atrium of the patient'"'"'s heart during a cardiac cycle, the system senses in the atrium for a retrograde P-wave. The system classifies the atrial response to the pacing pulse based on detection of the retrograde P-wave. The system may also sense for an atrial evoked response and utilize the atrial evoked response in classifying the cardiac pacing response. If capture is not detected, the system may deliver additional atrial pacing pulses to reduce atrial retrograde conduction. A backup pace may be delivered to prevent the atrial retrograde conduction if an atrial evoked response is not detected during a cardiac cycle. Alternatively, retrograde management may involve delaying a next scheduled pace may be until expiration of an atrial effective refractory period.

Claims

1. An atrial retrograde management method, comprising:

delivering a pacing pulse to an atrium during a cardiac cycle;

determining if the atrial pacing pulse captured the atrium;

sensing for an intrinsic activation of the ventricle during the cardiac cycle;

delivering a pacing pulse to the ventricle if the intrinsic ventricular activation is not detected; and

providing atrial retrograde management if the atrial pacing pulse did not capture the atrium, the atrial retrograde management involving the delivery of another pacing pulse.

2. The method of claim 1, wherein determining if the atrial pacing pulse captured the atrium comprises:

sensing for an atrial evoked response; and

determining that the atrial pacing pulse did not capture the atrium if the atrial evoked response is not detected.

3. The method of claim 2, wherein providing the atrial retrograde management comprises delivering a backup pace to the atrium if the atrial evoked response is not detected.

4. The method of claim 1, wherein determining if the atrial pacing pulse captured the atrium comprises:

sensing in the atrium for a retrograde P-wave; and

determining that the atrial pacing pulse did not capture the atrium if the retrograde P-wave is detected.

5. The method of claim 4, wherein providing the atrial retrograde management comprises delaying a scheduled atrial pacing pulse for a subsequent cardiac cycle if the retrograde P-wave is sensed and if the scheduled atrial pacing pulse is scheduled to occur before expiration of an atrial effective refractory period timed relative to the retrograde P-wave.

6. The method of claim 5, further comprising increasing an energy of the delayed atrial pacing pulse beyond a previously scheduled energy.

7. The method of claim 5, further comprising modifying the effective refractory period if the delayed atrial pace does not produce capture.

8. The method of claim 5, wherein further comprising delivering the scheduled atrial pacing pulse as scheduled if the scheduled atrial pace is not scheduled to occur before expiration of the atrial effective refractory period.

9. A cardiac system, comprising:

a plurality of implantable electrodes configured for one or more of sensing a cardiac signal and delivering cardiac pacing pulses to a patient'"'"'s heart;

a housing configured for implantation in the patient; and

a controller provided in the housing and coupled to the plurality of implantable electrodes, the controller configured to deliver a pacing pulse to an atrium of the patient'"'"'s heart during a cardiac cycle, determine if the atrial pacing pulse captured the atrium, sense for an intrinsic activation of the ventricle during the cardiac cycle, deliver a pacing pulse to the ventricle if the intrinsic ventricular activation is not detected, and deliver another pacing pulse timed to reduce atrial retrograde conduction if the atrial pacing pulse did not capture the atrium, the atrial retrograde conduction responsive to the ventricular pacing pulse or the intrinsic ventricular activation.

10. The cardiac system of claim 9, wherein the controller is configured to sense for an atrial evoked response and to classify the cardiac pacing response as a non-captured response if the atrial evoked response is not detected.

11. The cardiac system of claim 9, wherein the controller is configured to deliver a backup pace to the atrium to prevent atrial retrograde conduction if the atrial evoked response is not detected.

12. The cardiac system of claim 9, wherein the controller is configured to sense for a retrograde P-wave and to classify the cardiac pacing response as a non-captured response if the retrograde P-wave is detected.

13. The cardiac system of claim 9, wherein the controller is configured to delay a scheduled atrial pacing pulse for a subsequent cardiac cycle to reduce retrograde conduction during the subsequent cardiac cycle if the retrograde P-wave is detected and if the next scheduled atrial pacing pulse is scheduled to occur before expiration of an atrial effective refractory period.

14. The cardiac system of claim 13, wherein the controller is configured to increase an energy of the delayed atrial pacing pulse beyond a previously scheduled energy.

15. The cardiac system of claim 13, wherein the controller is configured to deliver the scheduled atrial pacing pulse as scheduled if the scheduled atrial pacing pulse is not scheduled to occur before expiration of an atrial effective refractory period.

16. The cardiac system of claim 13, wherein the controller is configured to modify the atrial effective refractory period if the delayed atrial pacing pulse does not produce capture.

17. An atrial retrograde management system, comprising:

means for delivering a pacing pulse to an atrium during a cardiac cycle;

means for determining if the atrial pacing pulse captured the atrium;

means for sensing for an intrinsic activation of the ventricle during the cardiac cycle;

means for delivering a pacing pulse to the ventricle if the intrinsic ventricular activation is not detected; and

means for delivering another pacing pulse to reduce atrial retrograde conduction if the atrial pacing pulse did not capture the atrium, the atrial retrograde conduction responsive to the ventricular pacing pulse or the intrinsic ventricular activation.

18. The system of claim 17, further comprising means for delaying a scheduled atrial pacing pulse for a subsequent cardiac cycle if the retrograde P-wave is sensed and if the scheduled atrial pacing pulse is scheduled to occur before expiration of an atrial effective refractory period timed relative to the retrograde P-wave.

19. The system of claim 18, further comprising means for modifying the effective refractory period if the delayed atrial pacing pulse does not produce capture.

20. The system of claim 18, wherein further comprising means for delivering the scheduled atrial pacing pulse as scheduled if the scheduled atrial pacing pulse is not scheduled to occur before expiration of the atrial effective refractory period.