Atrial capture verification

• US 20060129197A1
• 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, Daum, Douglas R., Garg, Ankur
• Granted Patent: US 7,587,240 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.

Claims

1. A method of classifying a cardiac response to pacing, comprising:

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

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

delivering a pacing pulse to the ventricle if the intrinsic ventricular activation is not sensed during the cardiac cycle;

sensing in the atrium for a retrograde P-wave, the retrograde P-wave responsive to the ventricular pacing pulse or the intrinsic ventricular activation; and

classifying the cardiac response to the atrial pacing pulse as a non-captured response if the retrograde P-wave is detected.

2. The method of claim 1, further comprising classifying the cardiac response as a possible captured response if the retrograde P-wave is not detected.

3. The method of claim 1, further comprising sensing in the atrium for an atrial evoked response associated with the atrial pacing pulse and classifying the cardiac response as a captured response if the atrial evoked response is detected.

4. The method of claim 1, wherein sensing for the retrograde P-wave comprises sensing for the retrograde P-wave during a time interval following sensing intrinsic ventricular activity or delivery of the ventricular pacing pulse.

5. The method of claim 4, wherein the time interval comprises a post ventricular atrial refractory period.

6. The method of claim 4, wherein the time interval begins about 100 milliseconds following delivery of the ventricular pacing pulse and ends about 500 milliseconds following delivery of the ventricular pacing pulse.

7. The method of claim 1, further comprising:

delivering additional atrial pacing pulses during cardiac cycles subsequent to the cardiac cycle;

delivering additional ventricular pacing pulses during the subsequent cardiac cycles;

sensing in the atrium for retrograde P-waves, the retrograde P-waves respectively responsive to the additional ventricular pacing pulses; and

classifying cardiac responses to the additional atrial pacing pulses as non-captured responses if the retrograde P-waves are detected.

8. The method of claim 7, wherein delivering atrial pulses, delivering ventricular pulses, sensing in the atrium, and classifying the cardiac responses are performed beat by beat during a pacing therapy delivered to a patient.

9. The method of claim 7, wherein delivering the atrial pacing pulses, delivering the ventricular pacing pulses, sensing in the atrium, and classifying the cardiac responses are performed during a test to determine a capture threshold of the atrium.

10. The method of claim 1, further comprising:

sensing for an atrial evoked response following delivery of the atrial pacing pulse; and

classifying the cardiac response to the atrial pacing pulse as a non-captured response if the retrograde P-wave is detected and the atrial evoked response is not detected.

11. The method of claim 10, wherein sensing in the atrium for a retrograde P-wave comprises sensing in the atrium during a post ventricular atrial refractory period.

12. The method of claim 10, further comprising classifying the cardiac response to the atrial pacing pulse as a captured response if the atrial evoked response is detected and the retrograde P-wave is not detected.

13. The method of claim 10, further comprising:

delivering additional atrial pacing pulses during cardiac cycles subsequent to the cardiac cycle;

sensing for atrial evoked responses following delivery of the additional atrial pacing pulses;

sensing in the atrium for retrograde P-waves, the retrograde P-waves responsive to ventricular pacing pulses or the intrinsic ventricular activations during the subsequent cardiac cycles; and

classifying the cardiac responses to the additional atrial pacing pulses based on the sensed atrial evoked responses and the sensed retrograde P-waves, wherein delivering the atrial pacing pulses, sensing in the atrium, and classifying the cardiac responses are performed beat by beat during a pacing therapy delivered to a patient.

14. The method of claim 10, further comprising:

delivering additional atrial pacing pulses during cardiac cycles subsequent to the cardiac cycle;

sensing for atrial evoked responses following delivery of the additional atrial pacing pulses;

sensing in the atrium for retrograde P-waves, the retrograde P-waves responsive to ventricular pacing pulses or the intrinsic ventricular activations during the subsequent cardiac cycles; and

classifying the cardiac responses to the additional atrial pacing pulses based on the sensed atrial evoked responses and the sensed retrograde P-waves, wherein delivering the atrial pacing pulses, sensing in the atrium, and classifying the cardiac responses are performed during a test to determine a capture threshold of the atrium.

15. 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;

a housing configured for implantation in the patient; and

a controller provided in the housing and coupled to the plurality of implantable electrodes, wherein the controller is configured to deliver a pacing pulse to an atrium of the patient'"'"'s heart during a cardiac cycle, sense for an intrinsic activation of a ventricle during the cardiac cycle, deliver a pacing pulse to the ventricle if the intrinsic activation is not sensed during the cardiac cycle, sense in the atrium for a retrograde P-wave in response to the ventricular pacing pulse or the intrinsic activation, and classify the cardiac response to the atrial pacing pulse as a non-captured response if the retrograde P-wave is detected.

16. The cardiac system of claim 15, wherein the controller is configured to classify the cardiac response to the atrial pacing pulse as a possible captured response if the atrial evoked response is not detected.

17. The cardiac system of claim 15, wherein the controller is further configured to sense for an atrial evoked response and to classify the cardiac response to the pacing pulse as a non-captured response if the atrial evoked response is not detected and the retrograde P-wave is detected.

18. The cardiac system of claim 15, wherein the controller is configured to sense for the retrograde P-wave during a post ventricular atrial refractory period.

19. A cardiac system, comprising:

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

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

means for delivering a pacing pulse to the ventricle if the intrinsic ventricular activation is not sensed during the cardiac cycle;

means for sensing in the atrium for a retrograde P-wave, the retrograde P-wave responsive to the ventricular pacing pulse or the intrinsic ventricular activation; and

means for classifying the cardiac response to the atrial pacing pulse as a non-captured response if the retrograde P-wave is detected.

20. The cardiac system of claim 19, further comprising:

means for sensing for an atrial evoked response following delivery of the atrial pacing pulse; and

means for classifying the cardiac response to the atrial pacing pulse as a non-captured response if the retrograde P-wave is detected and the atrial evoked response is not detected.