HEART FAILURE EVENT DETECTION USING MINIMUM HEART RATE

• US 20170001005A1
• Filed: 06/08/2016
• Published: 01/05/2017
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Yi, Averina, Viktoria A., Thakur, Pramodsingh Hirasingh
• Granted Patent: US 10,058,708 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• 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: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36507 controlled by gradient or slope of the heart potential
• CPC Class Codes: A61N 1/36535 controlled by body position or posture
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

Systems, devices, or methods can be used to detect an event, or series of events, that can indicate worsening of congestive heart failure (CHF), or can be used to identify a subject at an elevated risk for developing CHF. A CHF event predictor can be provided using a characteristic minimum of subject cardiac intervals. In an example, the subject cardiac intervals can be obtained during a night-time period or during periods of reduced subject physical activity. A CHF event predictor can be determined using information about physiologic signals received from a subject, such as from a physiologic sensor associated with an ambulatory or implantable medical device.

Claims

1. A congestive heart failure (CHF) event predictor method comprising:

obtaining information indicative of cardiac intervals over a first duration;

identifying a first characteristic minimum heart rate using the information indicative of the cardiac intervals over the first duration; and

determining a CHF event predictor using the identified first characteristic minimum heart rate.

2. The method of claim 1, wherein the obtaining the information indicative of the cardiac intervals over the first duration includes obtaining information about an intrinsic subject heart rate that is less than a lower rate pacing limit enforced by a cardiac rhythm management device.

3. The method of claim 1, wherein the obtaining the information indicative of the cardiac intervals includes obtaining information indicative of subject systolic cardiac intervals when a lower rate pacing limit is enforced by a cardiac rhythm management device.

4. The method of claim 3, wherein the obtaining the information indicative of the subject systolic cardiac intervals includes obtaining information about subject R-S2 intervals.

5. The method of claim 1, comprising receiving information indicative of a subject physical activity level, a subject posture, or a subject sleep/wake state, wherein the obtaining the information indicative of cardiac intervals corresponds to a respective one of a subject characteristic minimum physical activity level, a subject supine posture, or a subject sleep state.

6. The method of claim 1, comprising receiving time-of-day information, and wherein the obtaining the information indicative of the cardiac intervals over the first duration includes using the received time-of-day information.

7. The method of claim 6, wherein the obtaining the information indicative of the cardiac intervals over the first duration includes when the received time-of-day information indicates a specified night-time duration.

8. The method of claim 1, wherein the obtaining the information indicative of the cardiac intervals over the first duration includes obtaining information about an intrinsic subject heart rate that is less than a lower rate pacing limit enforced by a cardiac rhythm management device, and wherein the obtaining the information about the intrinsic subject heart rate that is less than a lower rate pacing limit includes intermittently reducing or intermittently suspending the lower rate pacing limit enforced by the cardiac rhythm management device.

9. The method of claim 8, wherein the intermittently lowering or suspending the lower rate pacing limit includes during a specified night-time duration.

10. The method of claim 9, wherein the intermittently lowering or suspending the lower rate pacing limit includes in response to a received indication of worsening heart failure.

11. The method of claim 1, wherein the identifying the first characteristic minimum heart rate using the information indicative of the cardiac intervals includes calculating an average of multiple candidate minimum heart rates corresponding to the first duration.

12. The method of claim 1, comprising:

obtaining information indicative of cardiac intervals over a second subsequent duration; and

identifying a second characteristic minimum heart rate using the information indicative of the cardiac intervals over the second subsequent duration;

wherein the determining the CHF event predictor includes using the identified first and second characteristic minimum intrinsic heart rates.

13. The method of claim 12, wherein the determining the CHF event predictor includes using rate of change information about the first characteristic minimum intrinsic heart rate relative to the second characteristic minimum intrinsic heart rate.

14. The method of claim 1, comprising:

obtaining information indicative of cardiac intervals over a second subsequent duration, the second subsequent duration including one or more night-time durations;

identifying one or more second characteristic minimum heart rates using the information indicative of the cardiac intervals over the second subsequent duration;

wherein the obtaining the information indicative of the cardiac intervals over the first duration includes obtaining the information over multiple-night time durations preceding the second subsequent duration; and

wherein the determining the CHF event predictor includes using the identified first and second characteristic minimum intrinsic heart rates.

15. A system comprising:

a processor circuit; and

a physiologic interval sensing circuit configured to receive information indicative of cardiac intervals over a first duration;

wherein the processor circuit is configured to;

identify a first characteristic minimum of a subject heart rate using the received information indicative of the cardiac intervals over the first duration; and

determine a congestive heart failure (CHF) event predictor using the identified first characteristic minimum of the subject heart rate.

16. The system of claim 15, comprising a therapy output circuit coupled to the processor circuit and configured to generate a subject therapy, the therapy output circuit coupleable to a therapy delivery electrode;

wherein the therapy output circuit is configured to update a subject cardiac therapy or a subject neural electrostimulation therapy when the determined CHF event predictor indicates an increased likelihood of a subject CHF event.

17. The system of claim 15, comprising:

an implantable medical device that includes the processor circuit and the physiologic interval sensing circuit; and

an external device in data communication with the implantable medical device, wherein the external device is configured to generate a subject or clinician alert when the CHF event predictor indicates an increased likelihood of the subject CHF event.

18. The system of claim 15, wherein the processor circuit is configured to temporarily suspend or decrease a lower rate pacing limit for a subject cardiac rhythm management therapy during a specified night-time interval, and wherein the physiologic interval sensing circuit is configured to receive the information indicative of the cardiac intervals over the first duration corresponding to the specified night-time interval.

19. A congestive heart failure (CHF) event predictor method comprising:

obtaining information indicative of cardiac intervals over a first duration, including obtaining information indicative of subject systolic intervals over the first duration;

identifying a first characteristic subject systolic interval duration trend using the information indicative of the subject systolic intervals over the first duration; and

determining a CHF event predictor using the identified characteristic subject systolic interval duration trend.

20. The method of claim 19, wherein the determining the CHF event predictor includes identifying a decreasing characteristic subject systolic interval duration.