Risk of death indicator

• US 20060036292A1
• Filed: 08/16/2004
• Published: 02/16/2006
• Est. Priority Date: 08/16/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Schwartz, Mark, Smith, Mitchell
• Granted Patent: US 7,277,756 B2
• Time in Patent Office: Days
• US Class Current: 607/19
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A system comprising an implantable medical device (IMD). The IMD comprises a ventricular heart signal sensing circuit to provide a ventricular heart signal, at least one sensor operable to provide an electrical signal representative of patient activity, a sensor interface circuit coupled to the at least one sensor to provide an activity signal, and a controller circuit coupled to the heart signal sensing circuit and the sensor interface circuit. The controller circuit is operable to determine whether ventricular ectopy occurs during recovery from exercise using the heart signal, and to set at least one warning indicator if ventricular ectopy occurs during the recovery from exercise.

Claims

1. A system comprising:

an implantable medical device (IMD) comprising;

a ventricular heart signal sensing circuit to provide a ventricular heart signal;

at least one sensor operable to provide an electrical signal representative of patient activity;

a sensor interface circuit coupled to the at least one sensor to provide an activity signal; and

a controller circuit coupled to the heart signal sensing circuit and the sensor interface circuit, wherein the controller circuit is operable to;

determine whether ventricular ectopy occurs during recovery from exercise using the heart signal; and

set at least one warning indicator if ventricular ectopy occurs during the recovery from exercise.

2. The system of claim 1, wherein the controller circuit is further operable to:

determine whether ventricular ectopy occurs during exercise using the heart signal; and

set at least one warning indicator if ventricular ectopy occurs during the exercise.

3. The system of claim 2, wherein the controller circuit is further operable to set at least one warning indicator if ventricular ectopy occurs during exercise and during recovery from exercise.

4. The system of claim 3, wherein the system further includes an external device operable to communicate with the implantable device, wherein the external device includes a display, and wherein the external device is operable to display information related to ventricular ectopy occurring during at least one of exercise and recovery from exercise.

5. The system of claim 4, wherein the information related to ventricular ectopy includes a warning indicator if ventricular ectopy occurred during at least one of exercise and recovery from exercise, and wherein the warning is indicated when the implantable medical device is interrogated by the external device.

6. The system of claim 5, wherein the external device is operable by a patient, and wherein the warning indicator includes an alarm.

7. The system of claim 4, wherein the implantable medical device includes a memory coupled to the controller circuit, the controller circuit operable to store in the memory information related to ventricular ectopy events that occur during at least one of exercise and recovery from exercise.

8. The system of claim 4, wherein the information related to ventricular ectopy includes a histogram of ventricular ectopy during at least one of exercise and recovery from exercise.

9. The system of claim 4, wherein the information related to ventricular ectopy includes trending of ventricular ectopy during at least one of exercise and recovery from exercise.

10. The system of claim 4, wherein the external device is operable to communicate with a communication network.

11. The system of claim 2, wherein the implantable medical device further includes a therapy circuit to provide a therapy to patient, the therapy circuit coupled to the controller circuit, and wherein the controller circuit is further operable to modify an output of the therapy circuit if ventricular ectopy occurs during at least one of exercise and recovery from exercise.

12. The system of claim 1, wherein the implantable medical device further includes:

a memory coupled to the controller circuit, the memory to store at least one morphology template representative of ventricular ectopy;

a sampling circuit coupled to the sensing circuit and the controller circuit, the sampling circuit to provide sampled values of the ventricular heart signal; and

wherein the controller circuit is further operable to determine whether ventricular ectopy occurs using a comparison of the sampled values to the at least one morphology template representative of ventricular ectopy.

13. The system of claim 1, wherein the sensor includes a minute ventilation (MV) sensor.

14. The system of claim 1, wherein the sensor includes an accelerometer.

15. The system of claim 1, wherein the at least one sensor includes both an MV sensor and an accelerometer sensor.

16. A method comprising:

monitoring a heart signal including ventricular depolarizations of a patient using an implantable medical device;

monitoring an activity level of the patient to detect exercise and recovery from exercise;

determining whether ventricular ectopy occurs during the recovery from exercise using the heart signal; and

providing at least one warning if at least one instance of ventricular ectopy occurs during the recovery from exercise.

17. The method of claim 16, wherein the method further includes:

determining whether ventricular ectopy occurs during the exercise using the heart signal; and

providing at least one warning if at least one instance of ventricular ectopy occurred during the exercise.

18. The method of claim 17, wherein the method further includes providing at least one warning if ventricular ectopy occurs during both exercise and recovery from exercise.

19. The method of claim 16, wherein providing a warning includes providing the warning when a number of instances of ventricular ectopy exceeds a numeric threshold.

20. The method of claim 16, wherein determining whether ventricular ectopy occurs includes:

comparing a morphology of the heart signal to a morphology of a predetermined cardiac condition of ventricular ectopy; and

determining whether a ventricular ectopy event occurs using the comparison.

21. The method of claim 16, wherein determining whether ventricular ectopy includes:

detecting ventricular depolarizations using the heart signal;

measuring intervals between ventricular depolarizations; and

determining whether a ventricular ectopy event occurs using the measured intervals.

22. The method of claim 16, wherein monitoring an activity level of the patient includes monitoring a minute ventilation (MV) of the patient using the implantable medical device.

23. The method of claim 16, wherein monitoring an activity level of the patient includes monitoring acceleration using the implantable medical device.

24. The method of claim 16, wherein providing a warning includes communicating a warning from the implantable medical device to an external device.

25. The method of claim 16, wherein providing a warning includes communicating information related to ventricular ectopy during at least one of exercise and recovery from exercise to an external device.

26. A system comprising:

an implantable medical device (IMD) comprising;

a ventricular heart signal sensing circuit to provide a ventricular heart signal;

at least one sensor operable to provide an electrical signal representative of patient activity;

a sensor interface circuit coupled to the at least one sensor to provide an activity signal; and

a controller circuit coupled to the heart signal sensing circuit and the sensor interface circuit, wherein the controller is operable to;

determine whether ventricular ectopy occurs during exercise using the heart signal; and

provide at least one warning indication if ventricular ectopy occurs during the exercise.

27. The system of claim 26, wherein the system further includes an external device operable to communicate with the implantable device, wherein the external device includes a display, and wherein the external device is operable to display information related to ventricular ectopy occurring during exercise.

28. The system of claim 27, wherein the information related to ventricular ectopy includes at least one warning that ventricular ectopy occurred during exercise.

29. A method comprising:

monitoring a heart signal including ventricular depolarizations of a patient using an implantable medical device;

monitoring an activity level of the patient to detect exercise;

determining whether ventricular ectopy occurs during the exercise using the heart signal; and

providing at least one warning if at least one instance of ventricular ectopy occurs during the exercise.

30. The method of claim 29, wherein providing a warning includes communicating at least one warning from the implantable medical device to an external device.

31. The method of claim 29, wherein providing at least one warning includes communicating information related to ventricular ectopy during exercise to an external device.