System and method for facilitating diagnosis of cardiac rhythm disorders with the aid of a digital computer

• US 9,408,551 B2
• Filed: 03/10/2016
• Issued: 08/09/2016
• Est. Priority Date: 11/14/2013
• Status: Active Grant

• Current Assignee: Bardy Diagnostics, Inc. (Baxter International Inc.)
• Original Assignee: Bardy Diagnostics, Inc. (Baxter International Inc.)
• Inventors: Bardy, Gust H., Dreisbach, Ezra M.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US15/066,883
• Publication Number:
  US 20160192853A1
• Time in Patent Office: 152 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/333 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence

Abstract

R-R interval data is presented in a format that includes relevant near field and far field ECG data. The near field view provides a “pinpoint” classical view at classical recording speed. The far field view that provides an “intermediate” lower resolution, pre- and post-event view. Both ECG data views are temporally keyed to the extended duration R-R interval data that is scaled non-linearly to maximize the visual differentiation for frequently-occurring heart rate ranges. All three views are presented simultaneously. The durations of the pinpoint view, the intermediate view, and the R-R interval plot are flexible and adjustable. Diagnostically relevant cardiac events can be identified and located to allow pre- and post-event heart rhythm data. The pinpoint “snapshot” and intermediate views of ECG data with the extended term R-R interval data comparatively depicts heart rate context and patterns of behavior prior to and after a clinically meaningful arrhythmia or patient concern.

Claims

1. A system for facilitating diagnosis of cardiac rhythm disorders with the aid of a digital computer, comprising:

an electrocardiogram (ECG) monitoring and recording device;

a download station adapted to retrieve cutaneous action potentials recorded for a set time period by the ECG monitoring and recording device as ECG data;

a processor and memory within which code for execution by the processor is stored, further comprising;

an identification module configured to identify a plurality of R-wave peaks in the ECG data;

a calculation module configured to calculate a difference between recording times of successive pairs of the R-wave peaks and to determine a heart rate associated with each time difference; and

a construction module configured to form an extended duration R-R interval plot over the set time period comprising each of the recording time differences and the associated heart rates; and

a display operatively coupled to the processor, for displaying;

the extended duration R-R interval plot with a temporal point of reference in the extended duration R-R interval plot; and

at least one accompanying ECG plot comprising at least part of the ECG data preceding and following the temporal point of reference as context.

2. A system in accordance with claim 1, further comprising at least one of:

the at least one accompanying ECG plot adapted to be presented as a ECG view produced at a traditional paper-based ECG recording speed; and

the at least one accompanying ECG plot adapted to be presented as a lower resolution, pre- and post-event contextual view relative to the temporal point of reference.

3. A system in accordance with claim 1, further comprising at least one of:

the construction module further configured to limit the heart rates to a range outside of which the time differences and the associated heart rates are excluded from the extended duration R-R interval plot; and

the construction module further configured to construct the extended duration R-R interval plot with a non-linear scale for the heart rates.

4. A system in accordance with claim 3, wherein the non-linear scale for the heart rates is determined in accordance with the equation:

5. A system in accordance with claim 1, further comprising:

an ambulatory ECG monitor disposed for wear on the patient'"'"'s chest along the sternum and adapted to record the cutaneous action potentials, the ambulatory ECG monitor adapted to be interfaced to a pair of cutaneous electrodes adhered to the patient'"'"'s skin along the sternal midline.

6. A system in accordance with claim 1, the processor further comprising:

an identification module configured to identify a potentially-actionable cardiac event within the ECG data, and to select the plurality of R-wave peaks from the ECG data prior to and after the potentially-actionable cardiac event.

7. A system in accordance with claim 1, the processor further comprising:

a diagnostic module configured to form a diagnosis based on heart rate variability patterns in the extended duration R-R interval plot.

8. A system in accordance with claim 7, further comprising:

the diagnostic module further configured to detect atrial fibrillation by identifying a Gaussian-type distribution of heart rate variability in the extended duration R-R interval plot.

9. A system in accordance with claim 7, further comprising:

a cardiac rhythm therapy delivery device programmed to deliver a therapy in response to the diagnosis.

10. A system in accordance with claim 1, wherein the processor is configured to form:

a background information plot with the extended duration R-R interval plot comprising one or more of activity amount, activity intensity, posture, syncope impulse detection, respiratory rate, blood pressure, oxygen saturation (SpO₂), blood carbon dioxide level (pCO₂), glucose, lung wetness, and temperature; and

background information layered to or keyed with the extended duration R-R interval plot comprising one or more of activity amount, activity intensity, posture, syncope impulse detection, respiratory rate, blood pressure, oxygen saturation (SpO₂), blood carbon dioxide level (pCO₂), glucose, lung wetness, and temperature.

11. A method for facilitating diagnosis of cardiac rhythm disorders with the aid of a digital computer, comprising the steps of:

monitoring and recording cutaneous action potentials of a patient;

retrieving the cutaneous action potentials as electrocardiogram (ECG) data for a set time period and identifying a plurality of R-wave peaks in the ECG data;

calculating a difference between recording times of successive pairs of the R-wave peaks and determining a heart rate associated with each time difference;

forming an extended duration R-R interval plot over the set time period comprising each of the recording time differences and the associated heart rates;

displaying the extended duration R-R interval plot and identifying a temporal point of reference in the extended duration R-R interval plot; and

displaying at least part of the ECG data preceding and following the temporal point of reference as context in at least one accompanying ECG plot.

12. A method in accordance with claim 11, further comprising at least one of the steps of:

presenting the at least one accompanying ECG plot as a ECG view produced at a traditional paper-based ECG recording speed; and

presenting the at least one accompanying ECG plot as a lower resolution, pre- and post-event contextual view relative to the temporal point of reference.

13. A method in accordance with claim 11, further comprising at least one of the steps of:

limiting the heart rates to a range outside of which the time differences and the associated heart rates are excluded from the extended duration R-R interval plot; and

constructing the extended duration R-R interval plot with a non-linear scale for the heart rates.

14. A method in accordance with claim 13, wherein the non-linear scale for the heart rates is determined in accordance with the equation:

15. A method in accordance with claim 11, further comprising the step of:

recording the cutaneous action potentials through an ambulatory ECG monitor disposed for wear on the patient'"'"'s chest along the sternum, the ambulatory ECG monitor adapted to be interfaced to a pair of cutaneous electrodes adhered to the patient'"'"'s skin along the sternal midline.

16. A method in accordance with claim 11, further comprising the steps of:

identifying a potentially-actionable cardiac event within the ECG data; and

selecting the plurality of R-wave peaks from the ECG data prior to and after the potentially-actionable cardiac event.

17. A method in accordance with claim 11, further comprising the step of:

forming a diagnosis based on heart rate variability patterns identified in the extended duration R-R interval plot.

18. A method in accordance with claim 17, further comprising the steps of:

detecting atrial fibrillation by identifying a Gaussian-type distribution of heart rate variability in the extended duration R-R interval plot.

19. A method in accordance with claim 18, further comprising the step of:

programming a therapy in response to the diagnosis into a cardiac rhythm therapy delivery device.

20. A method in accordance with claim 11, further comprising at least one of the steps of:

including a background information plot with the extended duration R-R interval plot comprising one or more of activity amount, activity intensity, posture, syncope impulse detection, respiratory rate, blood pressure, oxygen saturation (SpO₂), blood carbon dioxide level (pCO₂), glucose, lung wetness, and temperature; and

layering or keying background information with the extended duration R-R interval plot comprising one or more of activity amount, activity intensity, posture, syncope impulse detection, respiratory rate, blood pressure, oxygen saturation (SpO₂), blood carbon dioxide level (pCO₂), glucose, lung wetness, and temperature.

21. A non-transitory computer readable storage medium storing code for executing on a computer system to perform the method according to claim 11.