Systems and Methods for Use with an Implantable Medical Device for Detecting Stroke Based on Electrocardiac Signals

• US 20100198082A1
• Filed: 02/05/2009
• Published: 08/05/2010
• Est. Priority Date: 02/05/2009
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Park, Euljoon
• Granted Patent: US 8,241,221 B2
• Time in Patent Office: Days
• US Class Current: 600/483
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening

Abstract

Techniques are provided for detecting stroke within a patient using an implantable medical device in conjunction with an external confirmation system. In one example, a preliminary detection of stroke is performed by a subcutaneous monitor based on an analysis of features of an electrocardiogram (ECG) sensed within the patient. Exemplary ECG features indicative of possible stroke include the onset of prominent U-waves, the onset of notched T-waves, and changes in ST segment duration or QT duration or dynamic trends in these parameters. The monitor transmits a signal indicative of possible stroke to a bedside monitor or other external system, which generates a stroke questionnaire for use in confirming the stroke. Family members or other caregivers input answers to the questionnaire into the external system, which confirms or disconfirms the stroke. Emergency personnel can be automatically notified. Implantable systems that detect stroke based on intracardiac electrogram (IEGM) signals are also described herein.

Claims

1. A method for use with an implantable medical device for implant within a patient, the method comprising:

sensing electrocardiac signals using the implantable device;

detecting an indication of stroke within the patient based on predetermined changes in the electrocardiac signal; and

controlling at least one device function in response the indication of the stroke.

2. The method of claim 1 wherein detecting an indication of stroke includes detecting predetermined dynamic trends in the electrocardiac signal indicative of stroke.

3. The method of claim 1 wherein detecting the indication of stroke includes detecting one more of the onset of prominent U-waves, the onset of notched T-waves, changes in ST segment duration, and changes in QT duration.

4. The method of claim 3 wherein detecting the indication of stroke includes detecting trends toward one more of increasingly prominent U-waves, increasingly notched T-waves, changing ST segment durations, and changing QT durations.

5. The method of claim 1 for use with an external system wherein detecting the indication of stroke includes:

detecting a preliminary indication of a possible stroke based on the electrocardiac signals using the implantable device;

transmitting a signal indicative of a possible stroke from the implantable device to the external system;

a generating a questionnaire using the external system for confirming the stroke within the patient;

inputting answers to the questionnaire to confirm the stroke; and

outputting a warning signal from the external system upon confirmation of a stroke within the patient.

6. The method of claim 5 wherein the questionnaire includes questions directed to one or more of:

balance, speech, weakness/numbness, vision and severity of headache.

7. The method of claim 5 wherein the questionnaire includes questions directed to providing a quantitative measure of stroke-related neurologic deficit.

8. The method of claim 7 wherein the questionnaire includes questions drawn from one or more preselected stroke score questionnaires.

9. The method of claim 5 wherein outputting a warning signal includes outputting a signal to notify emergency personnel upon confirmation of a stroke.

10. The method of claim 1 wherein detecting stroke based on predetermined changes in the electrocardiac signal includes:

detecting a preliminary indication of a possible stroke based on the electrocardiac signal; and

distinguishing stroke from ischemia based on predetermined changes in the electrocardiac signal unique to stroke.

11. The method of claim 1 wherein controlling at least one device function in response the indication of the stroke includes generating an output signal indicative of stroke.

12. The method of claim 1 wherein sensing the electrocardiac signals includes sensing signals representative of an electrocardiogram (ECG).

13. The method of claim 12 wherein the implantable device is a subcutaneously-implantable monitoring device and wherein sensing the electrocardiac signals sensed is performed to sense signals representative of the ECG using the subcutaneously-implantable monitoring device.

14. The method of claim 1 wherein sensing the electrocardiac signals includes sensing signals representative of an intracardiac electrogram (IEGM).

15. The method of claim 1 wherein the implantable device includes an implantable cardiac rhythm management device and wherein sensing the electrocardiac signals sensed is performed to sense signals representative of the IEGM using the implantable cardiac rhythm management device.

16. A method for use with an implantable medical device for implant within a patient, along with an external system, the method comprising:

sensing electrocardiac signals using the implantable device;

detecting an indication of stroke within the patient using the implantable device based on predetermined changes in the electrocardiac signal indicative of stroke;

transmitting a signal indicative of a possible stroke from the implantable device to the external system;

generating a questionnaire using the external system for confirming the stroke within the patient;

inputting answers to the questionnaire to confirm the stroke; and

outputting a warning signal from the external system upon confirmation of a stroke within the patient.

17. A system for use with an implantable medical device for implant within a patient, the system comprising:

a electrocardiac signal sensing device for implant within the patient; and

an on-board stroke detector within the implantable medical device and operative to detect an indication of stroke within the patient based on predetermined changes in the electrocardiac signals indicative of stroke.

18. The system of claim 17 wherein the stroke detector comprises:

a preliminary ECG-based stroke detection unit; and

a preliminary stroke detection indicator generation unit.

19. A medical system incorporating an implantable medical device and an external system, comprising:

an electrocardiac signal sensing device within the implantable medical device;

a preliminary stroke detector within the implantable medical device operative to detect a preliminary indication of stroke within the patient based on predetermined changes in the electrocardiac signals indicative of stroke;

a transmitter within the implantable medical device operative to transmit a signal indicative of a possible stroke from the implantable device to the external system; and

a stroke confirmation system within the external system operative to confirm the stroke within the patient.

20. A system for use with an implantable medical device for implant within a patient, the system comprising:

means for sensing electrocardiac signals using the implantable device;

means for detecting an indication of stroke within the patient based on predetermined changes in the electrocardiac signal.