Ischemic heart disease detection

• US 6,514,195 B1
• Filed: 04/28/2000
• Issued: 02/04/2003
• Est. Priority Date: 04/28/2000
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Ferek-Petric, Bozidar
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Assistant Examiner(s): Oropeza, Frances P.
• Application Number:
  US09/558,870
• Time in Patent Office: 1,012 Days
• Field of Search: 600/17, 600/374, 600/438, 600/454, 600/467, 600/468, 600/504, 600/505, 600/509, 600/513, 600/516, 600/517, 600/519, 607/4, 607/5, 607/9, 607/11, 607/17, 607/62, 607/66, 607/119, 607/120, 607/122
• US Class Current: 600/17
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3962 in combination with another heart therapy
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

An implantable medical device system for detecting cardiac conditions such the long-term ischemic heart disease, an occlusion of a coronary artery by a thrombus or an impending as a myocardial infarction. The implantable medical device (IMD) system includes a sensor that outputs a blood flow rate signal representing a rate of blood flow through a coronary sinus of a patient'"'"'s heart. An implantable medical device (IMD) includes a microcomputer circuit configured to analyze the blood flow rate signal and detect a cardiac condition as a function of the blood flow rate signal. The system can also includes an implantable lead that senses electrical activity from the patient'"'"'s heart. The microcomputer circuit monitors an ST segment of the electrical activity signal and detects a cardiac condition as a function of blood flow rate signal in conjunction with the electrical activity signal.

Claims

1. An implantable medical device system comprising:

a sensor to output a blood flow rate signal representing a rate of blood flow through a coronary sinus of a patient'"'"'s heart;

an implantable medical device (IMD) coupled to the sensor;

a circuit embedded within the IMD configured to analyze the blood flow rate signal and an ST signal; and

,

an implantable lead to coupled to the circuit embedded within the IMD, the implantable lead configured to output the ST signal sensed from the patient'"'"'s heart;

wherein a cardiac condition is detected when the circuit embedded in the IMD detects a sharp drop in the blood flow rate followed in more than one second by a sharp elevation in the ST signal.

2. The system of claim 1, wherein the cardiac condition includes ischemic heart disease.

3. The system of claim 1, wherein the cardiac condition includes a myocardial infarction.

4. The system of claim 1, wherein the cardiac condition includes a thrombus occluding a coronary artery.

5. The system of claim 1, wherein a microcomputer circuit is configured to determine a rate of change for the blood flow rate signal.

6. The system of claim 1 further comprising a drug deliver system to provide a therapeutic drug when the IMD detects the cardiac condition.

7. The system of claim 6, wherein the therapeutic drug is a thrombolytic.

8. The system of claim 1, wherein the sensor is integrated in a coronary sinus lead for implantation in the coronary sinus of the patient'"'"'s heart.

9. The system of claim 1, wherein the IMD includes an alarm activated by a microcomputer circuit when the cardiac condition is detected.

10. The system of claim 9, wherein the alarm comprises an audible alarm.

11. The system of claim 9, wherein the alarm comprises a muscle-stimulating device.

12. The system of claim 1 further comprising a pacing lead coupled to the IMD, and further wherein the IMD comprises pacing control circuit to deliver pacing pulses as a function of the sensed blood flow rate signal and a sensed electrical activity.

13. The system of claim 1, wherein a microcomputer circuit is configured to log the sensed blood flow rate signal over a period of time, and further wherein the microcomputer circuit detects the cardiac condition by analyzing a trend of the blood flow rate signal.

14. The system of claim 1 and further including a defibrillation electrode to carry defibrillation pulses from the IMD to the patient'"'"'s heart.

15. The system of claim 1, wherein a microcomputer circuit is configured to calculate the integral of the blood flow signal.

16. A method for pacing a patient'"'"'s heart using an implanted medical device comprising:

sensing a rate of blood flow through a coronary sinus of a patient'"'"'s heart;

sensing an ST signal from a patient'"'"'s heart;

detecting a cardiac condition when there is a sharp drop in the rate of blood flow followed in more than one second by a sharp elevation in the ST signal.

17. The method of claim 16, wherein detecting the cardiac condition includes detecting ischemic heart disease.

18. The method of claim 16, wherein detecting the cardiac condition includes detecting a myocardial infarction.

19. The method of claim 16, wherein detecting the cardiac condition includes detecting a thrombus occluding a coronary artery.

20. The method of claim 16 further including calculating a rate of change for the blood flow.

21. The method of claim 16 further comprising delivering a therapeutic drug when the cardiac condition is detected.

22. The method of claim 16, wherein the therapeutic drug is a thrombolytic.

23. The method of claim 16 further including activating an alarm when the cardiac condition is detected.

24. The method of claim 23, wherein activating an alarm includes activating an audible alarm.

25. The method of claim 23, wherein activating an alarm includes activating a musclestimulating alarm.

26. The method of claim 16 further including deliver pacing pulses as a function of the sensed blood flow rate signal and the sensed electrical activity.

27. The method of claim 16 further including:

logging the sensed blood flow rate signal over a period of time; and

analyzing the log to detect the cardiac condition.

28. The method of claim 16 further including calculating the integral of the sensed blood flow.