Cardiac pacing apparatus and method for continuous capture management

• US 7,831,303 B2
• Filed: 06/17/2003
• Issued: 11/09/2010
• Est. Priority Date: 06/17/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Combs, William J., Rueter, John C.
• Primary Examiner(s): Evanisko; George R
• Assistant Examiner(s): HOLMES, REX R
• Application Number:
  US10/462,993
• Publication Number:
  US 20040260352A1
• Time in Patent Office: 2,702 Days
• Field of Search: 607 27- 28, 607/23
• US Class Current: 607/27
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

An implantable cardiac stimulation system and method having continuous capture management capabilities are provided. Continuous capture management is realized by continuously monitoring for secondary effects of loss of capture, thereby effectively providing continuous capture management in any heart chamber without encountering the limitations normally associated with evoked response sensing. A pacing threshold search is triggered upon detecting a secondary indicator of loss of capture. Secondary indicators of loss of capture may be lead-related changes, changes related to the occurrence of atrial sensed events, changes related related to the occurrence of ventricular sensed or paced events, and/or changes related to a monitored physiological condition.

Claims

1. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include atrial sensed events, the atrial sensed events include an increased frequency of sensed atrial refractory events, an increased frequency of PVARP extensions, a detected pattern of retrograde conduction, an increased frequency of mode switching, or an increased duration of non-atrial tracking episodes.

2. The method of claim 1, wherein performing the pacing threshold search includes performing the threshold test on an atrium if a threshold test first performed on the ventricle fails to indicate a loss of pacing capture.

3. The method of claim 1, wherein performing the pacing threshold search includes performing the threshold test on the atrium when the threshold test first performed on the ventricle indicates loss of pacing capture if the monitoring continues to provide a secondary indicator of loss of pacing capture after a ventricular threshold has been corrected.

4. The method of claim 1, wherein pacing capture management is monitored on a continuous basis.

5. The method of claim 1, further comprising

responding to a secondary indicator of loss of pacing capture if the pacing threshold search fails to indicate a loss of pacing capture,

wherein responding includes one of:

adjusting sensitivity levels, adjusting a refractory period, adjusting a blanking period, adjusting a pacing mode, and adjusting the delivery of pacing therapy.

6. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle,

wherein the secondary indicators of loss of pacing capture include one of;

detecting sleep apnea, and detecting Cheyne-Stokes breathing.

7. An implantable medical device comprising:

a pulse generator for delivering pacing pulses;

at least one lead in electrical communication with the pulse generator for delivering the pacing pulses to cardiac tissue; and

a microprocessor for controlling the pulse generator to generate pacing pulses according to a pacing therapy, receiving sensed data from the at least one lead, monitoring the sensed data for a secondary indicator of loss of pacing capture during the pacing therapy, determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle, and performing a pacing threshold search when the secondary indicator of loss of pacing capture is sensed, the pacing threshold search performed on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and the pacing threshold search performed on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include one of the following;

an increased frequency of sensed atrial refractory events, an increased frequency of PVARP extensions, a detected pattern of retrograde conduction, an increased frequency of mode switching, and an increased duration of non-atrial tracking episodes.

8. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include atrial sensed events, the atrial sensed events include an increased frequency of PVARP extensions.

9. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include atrial sensed events, the atrial sensed events include a detected pattern of retrograde conduction.

10. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include atrial sensed events, the atrial sensed events include an increased frequency of mode switching.

11. A method of providing pacing capture management in an implantable medical device, the method comprising:

delivering a pacing therapy through at least one lead;

monitoring for secondary indicators of loss of pacing capture;

performing a pacing threshold search if a secondary indicator of loss of pacing capture is monitored

determining whether the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium or more likely indicates a loss of pacing capture in a ventricle; and

performing the pacing threshold search on the atrium first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in an atrium and performing the pacing threshold search on the ventricle first if the secondary loss of pacing capture indicator more likely indicates a loss of pacing capture in a ventricle

wherein the secondary indicators of loss of pacing capture include atrial sensed events, the atrial sensed events include an increased duration of non-atrial tracking episodes.