Automatic capture verification using electrocardiograms sensed from multiple implanted electrodes

• US 20060253164A1
• Filed: 05/09/2005
• Published: 11/09/2006
• Est. Priority Date: 05/09/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Meyer, Scott A., Zhang, Yi, McCabe, Aaron R., Ding, Jiang
• Granted Patent: US 7,509,170 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.

Claims

1. A method of classifying a cardiac response to one or more pacing pulses, comprising:

sensing a plurality of composite cardiac signals using a plurality of implantable electrodes;

performing a source separation using the sensed plurality of composite cardiac signals;

producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences based on the source separation; and

classifying a cardiac response to the one or more pacing pulses using one or more characteristics associated with one or both of the one or more cardiac signal vectors and the signals associated with the one or more cardiac signal vectors.

2. The method of claim 1, wherein classifying the cardiac response comprises classifying the cardiac response as capture or non-capture.

3. The method of claim 1, wherein classifying the cardiac response comprises classifying the cardiac response as fusion or intrinsic cardiac activity.

4. The method of claim 1, wherein the one or more characteristics comprise an angle or an angle change of the one or more cardiac signal vectors.

5. The method of claim 1, wherein the one or more characteristics comprise a predetermined range of angles of the one or more cardiac signal vectors, and wherein classifying the cardiac response comprises determining if the vector falls within the predetermined range.

6. The method of claim 1, wherein the one or more characteristics comprise a morphology of one or more signals associated with the one or more cardiac signal vectors.

7. The method of claim 1, wherein the one or more characteristics comprise a morphological change, relative to a baseline, of the one or more signals associated with the one or more cardiac signal vectors.

8. The method of claim 1, wherein the one or more characteristics comprise a predetermined range of angles of the one or more cardiac signal vectors, and wherein classifying the cardiac response comprises discriminating between left ventricular non-capture and right ventricular non-capture in response to delivery of bi-ventricular pacing pulses.

9. The method of claim 1, comprising recommending an action based on the classified cardiac response to the one or more pacing pulses.

10. The method of claim 1, comprising triggering one or more threshold tests or increasing one or more pacing amplitudes in response to classifying the cardiac response as non-capture.

11. The method of claim 1, wherein classifying the cardiac response comprises discriminating between one or more of capture, non-capture, fusion, and pseudofusion.

12. A cardiac system adapted to facilitate classification of a cardiac response to a pacing pulse, comprising:

a plurality of implantable electrodes configured for sensing a composite signal, thereby providing a plurality of composite cardiac signals;

a housing configured for implantation in a patient;

a controller provided in the housing and coupled to the implantable electrodes;

memory; and

a signal processor coupled to the memory, the signal processor configured to perform a source separation using the sensed plurality of composite cardiac signals, the source separation producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences, the signal processor further configured to store vector information in the memory, wherein at least one of the controller and the signal processor is configured to classify the cardiac response to the pacing pulse using the vector information stored in the memory.

13. The system of claim 12, wherein the signal processor is provided in a patient-external device or system, the signal processor and the controller coupled to respective communication devices to facilitate wireless communication between the signal processor and the controller.

14. The system of claim 12, further comprising a lead configured for subcutaneous non-intrathoracic placement in a patient and coupled to the controller, wherein at least one of the plurality of implantable electrodes is supported by the lead.

15. The system of claim 12, wherein the housing comprises a header configured for coupling a lead to the housing, and at least one of the plurality of implantable electrodes is provided on the header.

16. The system of claim 12, wherein at least one of the plurality of implantable electrodes is provided on the housing.

17. The system of claim 12, wherein the signal processor implements a blind source separation algorithm.

18. The system of claim 12, wherein the at least one of the controller and the signal processor is configured to classify the cardiac response as one of capture, non-capture, fusion, or intrinsic cardiac activity.

19. The system of claim 12, wherein the cardiac system is configured to support one or more of atrial pacing, ventricular pacing, and bi-ventricular pacing and adapted to facilitate classification of the cardiac response to pacing pulses delivered in accordance with one or more of an atrial pacing therapy, a ventricular pacing therapy, and a bi-ventricular pacing therapy.

20. An implantable cardiac device, comprising:

means for sensing a plurality of composite cardiac signals using a plurality of implantable cardiac electrodes;

means for performing a source separation using the sensed plurality of composite cardiac signals, the source separation producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences; and

means for classifying the cardiac response to the pacing pulse using a characteristic associated with the one or more cardiac signal vectors.

21. The device of claim 20, wherein the classifying means comprises means for detecting a change in the characteristic associated with the one or more cardiac signal vectors relative to a baseline.