ELECTROCARDIOLOGIC DEVICE FOR ASSISTED DIAGNOSIS FOR THE DIAGNOSTIC OF BRUGADA SYNDROME OR EARLY REPOLARIZATION SYNDROME

• US 20090137916A1
• Filed: 10/21/2008
• Published: 05/28/2009
• Est. Priority Date: 10/24/2007
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Ela Medical S.A. (LivaNova Plc)
• Inventors: Extramiana, Fabrice, Maison-Blanche, Pierre
• Granted Patent: US 8,116,859 B2
• Time in Patent Office: Days
• US Class Current: 600/516
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/361 Detecting fibrillation

Abstract

Electrocardiologic device for assisted diagnosis, preferably for the diagnosis of Brugada syndrome or Early Repolarization syndrome. This device allows characterizing the ventricular repolarization wave of an ECG signal collected from a patient. Extracting out of the ECG signal, for each heart beat, an ST segment is constituted of a successsion of samples of the ventricular repolarization wave, taken within a time window ([Q_ON+80 ms, Q_ON+140 ms]) of a predetermined duration spreading from a moment of window onset defined by a time offset applied to a predetermined temporal origin given by the moment (Q_ON) of appearance of the QRS complex, whose time position is determined on the ECG signal for each heart beat. Quantizing computes an elevation index compared to a predetermined reference level (BL), and analyzing over a succession of heart beats the persistence and/or variation of this elevation index.

Claims

1. A device for an assisted electrocardiologic diagnosis comprising means for characterizing the ventricular repolarization wave of an ECG signal collected from a patient, said ECG signal having been preliminarily sampled and digitized, said device comprising:

means for determining the time position of a moment of appearance on said ECG signal for each heart beat

extracting means for isolating out of the ECG signal, for each heart beat, an ST segment comprising a succession of samples of the ventricular repolarization wave, taken within a time window of a predetermined width, said width having a moment of window onset, said moment of window onset having a time offset from a predetermined temporal origin;

quantizing means for computing an elevation index of said ST segment compared to a predetermined reference level; and

means for analyzing over a succession of heart beats, at least one among the group consisting of persistence and variation of said elevation index,

wherein said predetermined temporal origin comprises said determined moment of appearance of the QRS complex.

2. The device of claim 1, wherein said time offset from the predetermined temporal origin ranges from between 60 and 100 ms.

3. The device of claim 1, wherein said predetermined width of the time window ranges from between 50 and 80 ms.

4. The device of claim 1, wherein said quantizing means further comprises means for creating a matrix providing, for a series of samples (S_i) taken within said time window, the amplitude (V_i) of corresponding samples of the ECG signal.

5. The device of claim 4, wherein said series of samples is a subset of the samples of said succession of samples of the ventricular repolarization wave.

6. The device of claim 4, wherein said device comprises means for concurrently analyzing a plurality of ECG signals coming from different derivations, and means for applying to the matrix a mathematical transform selected from among the group consisting of:

a principal component analysis, a Karhunen-Loeve transform, and a derivative calculation.

7. The device of claim 1, wherein said quantizing means further comprises integrating means for computing the surface area defined by the ECG signal over the width of said time window, for determining the elevation index.

8. The device of claim 1, wherein said analyzing means comprises means for evaluating an average level of the elevation index based upon at least one of:

during a given duration and over a given number of heart beats, and for analyzing the long term variations of the elevation index around this average level.

9. The device of claim 8, wherein the analyzing means comprises classifying means for distributing into a plurality of classes the successive values of said elevation index collected based upon at least a given duration and a given number of successive heart beats, said distribution into classes being operated as a function of a parameter measured by the device or known thereby.

10. The device of claim 9, further comprising means for analyzing at least one of a persistence and a variation of the elevation index, separately for each class.

11. The device of claim 9, wherein said parameter is one selected from among the group comprising of:

heart rate, RR interval, diurnal nocturnal or prandial of the moment of analysis, the patient'"'"'s level of activity, the patient'"'"'s body temperature, the natural or paced nature of the heart beat, the sinusal or extrasystolic character of the heart beat, and the existence of a drug treatment.

12. The device of claim 1, wherein said analyzing means comprises means for searching within the ST segment, the presence of a coved pattern that is characteristic of a one of a Brugada syndrome and an Early Repolarization Syndrome.

13. The device of claim 1 further comprising a graphical display of the variations over time of said elevation index.

14. The device of claim 1, wherein said analyzing means further comprises means for providing information of assisted diagnosis comprising a risk marker.

15. The device of claim 14, wherein the information comprising a risk marker is provided when the elevation index computed by the quantizing means is greater than a predefined threshold during a predetermined duration.

16. The device of claim 14, wherein the information comprising a risk marker is provided when the elevation index computed by the quantizing means is greater than a predefined threshold over a given number of heart beats.

17. The device of claim 14, wherein the information comprising a risk marker is provided when the elevation index computed by the quantizing means is greater than a predefined threshold during a predetermined duration and over a given number of heart beats.

18. The device of claim 14, wherein said analyzing means further comprises means for concurrently analyzing a plurality of ECG signals coming from more than two different precordial derivations, and wherein the information comprising a risk marker is provided when the elevation index computed by said quantizing means is greater than a predefined threshold during a predetermined duration, for ECG signals coming from at least two of said precordial derivations.

19. The device of claim 14, wherein said analyzing means further comprises means for concurrently analyzing a plurality of ECG signals coming from more than two precordial derivations, and wherein the information comprising a risk marker is provided when the elevation index computed by said quantizing means is greater than a predefined threshold over a given number of heart beats, for ECG signals coming from at least two of said precordial derivations.

20. The device of claim 14, wherein said device is able to concurrently analyze a plurality of ECG signals coming from different precordial derivations, and wherein the information comprising a risk marker is provided when the elevation index computed by said quantizing means is greater than a predefined threshold during a predetermined duration and over a given number of heart beats, for ECG signals coming from at least two of said precordial derivations.

21. The device of claim 1, wherein said device is an external recorder able to be connected to external electrodes for collecting cutaneous ECG.

22. The device of claim 1, wherein said device is an implanted device comprising electrodes for collecting a subcutaneous ECG.

23. The device of claim 1, wherein said device is an implanted device able to be connected to electrodes for collecting intracardiac or epicardiac EGM signals, said device further comprising means for reconstructing ECG signals based upon said collected EGM signals.

24. The device of claim 1, wherein said device is an implanted device of the pacemaker, defibrillator or pacemaker/defibrillator or resynchronization device, said device further comprising means for delivering pacing pulses, defibrillation shocks or both, controlled by said means for characterizing the ventricular repolarization wave.

25. A software control module for processing signals representative of an ECG signal collected from a patient for characterizing the ventricular repolarization wave of the ECG signal, said ECG signal having been preliminarily sampled and digitized, comprising:

a first instruction set for determining the time position of a moment of appearance of a QRS complex in said ECG signal for each heart beat

a second instruction set for isolating out of the ECG signal, for each heart beat, an ST segment comprising a succession of samples of the ventricular repolarization wave, taken within a time window of a predetermined width, said width having a moment of window onset, said moment of window onset having a time offset from a predetermined temporal origin;

a third instruction set for fo computing an elevation index of said ST segment compared to a predetermined reference level; and

a fourth instruction set for analyzing over a succession of heart beats, at least one among the group consisting of persistence and variation of said elevation index.

26. The software control module of claim 25, wherein said second instruction set time offset is a programmable value selected from between 60 and 100 ms.

27. The software control module of claim 25, wherein said second instruction set predetermined width of the time window is a programmable value selected from between 50 and 80 ms.

28. The software control module of claim 25, wherein said third instruct set means further comprises an instruction set for creating a matrix providing, for a series of samples (S_i) taken within said time window, the amplitude (V_i) of corresponding samples of the ECG signal.

29. The software control module of claim 28, wherein said series of samples is a subset of the samples of said succession of samples of the ventricular repolarization wave.

30. The software control module of claim 28, wherein said fourth instruction set further comprises an instruction set for concurrently analyzing a plurality of ECG signals coming from different derivations, and applying to the matrix a mathematical transform selected from among the group consisting of:

a principal component analysis, a Karhunen-Loeve transform, and a derivative calculation.

31. The software control module of claim 25, wherein said third instruction set further comprises an instruction set for computing the surface area defined by the ECG signal over the width of said time window, for determining the elevation index.

32. The software control module of claim 25, wherein said fourth instruction set further comprises an instruction set for evaluating an average level of the elevation index based upon at least one of:

during a given duration and over a given number of heart beats, and for analyzing the long term variations of the elevation index around this average level.

33. The software control module of claim 32, wherein the fourth instruction set comprises an instruction set for distributing into a plurality of classes the successive values of said elevation index collected based upon at least a given duration and a given number of successive heart beats, said distribution into classes being operated as a function of a parameter measured by the device or known thereby.

34. The software control module of claim 33, further comprising a fifth instruction set for analyzing at least one of a persistence and a variation of the elevation index, separately for each class.

35. The software control module of claim 33, wherein said parameter is one selected from among the group comprising of:

heart rate, RR interval, diurnal nocturnal or prandial of the moment of analysis, the patient'"'"'s level of activity, the patient'"'"'s body temperature, the natural or paced nature of the heart beat, the sinusal or extrasystolic character of the heart beat, and the existence of a drug treatment.

36. The software control module of claim 25, wherein said fourth instruction set further comprises an instruction set for searching within the ST segment, the presence of a coved pattern that is characteristic of a one of a Brugada syndrome and an Early Repolarization Syndrome.

37. The software control module of claim 25, wherein said fourth instruction set further comprises a fifth instruction set for providing information of assisted diagnosis comprising a risk marker.

38. The software control module of claim 37, wherein the fifth instruction set provides said risk marker when the computed elevation index is greater than a predefined threshold during a predetermined duration.

39. The software control module of claim 37, wherein the fifth instruction set provides said risk marker when the computed elevation index is greater than a predefined threshold over a given number of heart beats.

40. The software control module of claim 37, wherein the fifth instruction set provides said risk marker when the computed elevation index is greater than a predefined threshold during a predetermined duration and over a given number of heart beats.

41. The software control module of claim 37, wherein said fourth instruction set further comprises an instruction set for concurrently analyzing a plurality of ECG signals coming from more than two different precordial derivations, and wherein the fifth instruction set provides said risk marker the computed elevation index is greater than a predefined threshold during a predetermined duration, for ECG signals coming from at least two of said precordial derivations.

42. The software control module of claim 37, wherein said fourth instruction set further comprises an instruction set for concurrently analyzing a plurality of ECG signals coming from more than two precordial derivations, and wherein the fifth instruction set proivides said risk marker when the computed elevation index is greater than a predefined threshold over a given number of heart beats, for ECG signals coming from at least two of said precordial derivations.

43. The software control module of claim 37, wherein said fourth instruction set further comprises an instruction set for concurrently analyzing a plurality of ECG signals coming from different precordial derivations, and wherein the fifth instruction set provides said risk marker when the computed elevation index is greater than a predefined threshold during a predetermined duration and over a given number of heart beats, for ECG signals coming from at least two of said precordial derivations.