Method and apparatus for arrhythmia classification using atrial signal mapping

• US 7,328,063 B2
• Filed: 11/30/2004
• Issued: 02/05/2008
• Est. Priority Date: 11/30/2004
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Yongxing, Gilkerson, James O., Thompson, Julie, Zhang, Yunlong
• Primary Examiner(s): Layno; Carl
• Assistant Examiner(s): Gedeon; Brian T.
• Application Number:
  US11/000,133
• Publication Number:
  US 20060116594A1
• Time in Patent Office: 1,162 Days
• Field of Search: 600/515
• US Class Current: 600/515
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

Claims

1. A cardiac rhythm management system coupled to a heart having a right atrium (RA) connected to a superior vena cava, a left atrium (LA), a left ventricle (LV), a sinoatrial (SA) node, an atrial septum, a coronary sinus, and a coronary vein, the system comprising:

a high RA (HRA) electrode configured for placement near the SA node to sense an RA electrogram;

an LA electrode configured for placement near the LA to sense an LA electrogram;

an atrial septal electrode configured for placement in or near the atrial septum to sense an atrial septal electrogram;

a ventricular electrode configured for placement in or near a ventricle to sense a ventricular electrogram; and

an implantable medical device coupled to the HRA electrode, the LA electrode, the atrial septal electrode, and the ventricular electrode, the implantable medical device including a sensing circuit to sense the RA electrogram, the LA electrogram, the atrial septal electrogram, and the ventricular electrogram, an arrhythmia detection circuit to detect a tachyarrhythmia based in at least one of the RA electrogram, the LA electrogram, the atrial septal electrogram, and the ventricular electrogram, and an arrhythmia classification circuit to classify the detected tachyarrhythmia, the arrhythmia classification circuit including;

an atrial signal mapping module configured to map an atrial activation sequence using the RA electrogram, the LA electrogram, and the atrial septal electrogram, the atrial activation sequence indicative of an order of regional depolarizations during an atrial depolarization; and

an atrial pattern analyzer configured to classify the detected tachyarrhythmia using the atrial activation sequence.

2. The system of claim 1, wherein the implantable medical device further comprises:

an event detection circuit, coupled to the sensing circuit, to detect an RA event from the RA electrogram and an LA event from the LA electrogram during an atrial depolarization; and

an inter-atrial interval measurement circuit, coupled to the event detection circuit, to measure a time interval between the RA event and the LA event.

3. The system of claim 1, further comprising a first lead including the HRA electrode, the LA electrode, and the atrial septal electrode, and wherein the HRA electrode is configured for placement in the RA or the superior vena cava near the SA node, the LA electrode is configured for placement in the coronary sinus or the coronary vein near the LA, and the atrial septal electrode is configured for placement in the coronary sinus near the atrial septum.

4. The system of claim 3, wherein the first lead further comprises an LV electrode configured for placement in the coronary vein over the LV to sense an LV electrogram.

5. The system of claim 4, wherein the atrial pattern analyzer is configured to classify the tachyarrhythmia using the atrial activation sequence and the LV electrogram.

6. A system of claim 1, further comprising a first lead including at least the HRA electrode and a second lead including at least the LA electrode, and wherein the HRA electrode is configured for placement in the RA or the superior vena cava near the SA node, and the LA electrode is configured for placement in the coronary sinus or the coronary vein near the LA.

7. The system of claim 6, wherein the first lead further comprises the atrial septal electrode, and wherein the atrial septal electrode is configured for placement in the RA in or near the atrial septum.

8. The system of claim 6, wherein the second lead further comprises the atrial septal electrode, and wherein the atrial septal electrode is configured for placement in the coronary sinus near the atrial septum.

9. The system of claim 1, wherein the atrial pattern analyzer is configured to classify the tachyarrhythmia using the atrial activation sequence and the ventricular electrogram.

10. The system of claim 1, further comprising an external system communicatively coupled to the implantable medical device.

11. The system of claim 10, wherein the external system comprises an external device communicatively coupled to the implantable medical device via telemetry.

12. The system of claim 11, wherein the external system further comprises:

a telecommunication network coupled to the external device; and

a remote device coupled to the telecommunication network.

13. A system for tachyarrhythmia detection and classification, the system comprising:

a sensing circuit to sense a plurality of atrial electrograms and at least one ventricular electrogram;

a rate detection circuit, coupled to the sensing circuit, to detect an atrial rate from at least one atrial electrogram of the plurality of atrial electrograms and a ventricular rate from the at least one ventricular electrogram;

an arrhythmia detection circuit, coupled to the rate detection circuit, to detect a tachyarrhythmia using at least one of the atrial rate and the ventricular rate; and

an arrhythmia classification circuit coupled to the sensing circuit, the rate detection circuit, and the arrhythmia detection circuit, the arrhythmia classification circuit including;

a 1;

1 tachyarrhythmia detector adapted configured to classify the detected tachyarrhythmia as a 1;

1 tachyarrhythmia when the atrial rate and the ventricular rate are substantially equal;

an atrial signal mapping module configured to map an atrial activation sequence using the plurality of atrial electrograms, the atrial activation sequence indicative of an order of regional depolarizations during an atrial depolarization; and

an atrial pattern analyzer configured to classify the 1;

1 tachyarrhythmia using the atrial activation sequence.

14. The system of claim 13, wherein the atrial pattern analyzer comprises at least two of:

a right atrial pattern matching module to detect a supraventricular tachyarrhythmia of a right atrial origin by comparing the atrial activation sequence to a predetermined right atrial pattern template sequence;

a left atrial pattern matching module to detect an supraventricular tachyarrhythmia of a left atrial origin by comparing the atrial activation sequence to a predetermined left atrial pattern template sequence; and

an atrial septal pattern matching module to detect one of a supraventricular tachyarrhythmia of atrial septal origin and a ventricular tachyarrhythmia by comparing the atrial activation sequence to a predetermined atrial septal pattern template sequence.

15. The system of claim 13, wherein the arrhythmia classification circuit further comprises a morphology analyzer, coupled to the atrial pattern analyzer, to further classify the 1:

1 tachyarrhythmia using morphological features of one or more signals selected from the plurality of atrial electrogram and the at least one ventricular electrogram.

16. The system of claim 15, wherein the morphology analyzer further comprises a ventricular tachyarrhythmia detector to discriminate a ventricular tachyarrhythmia from a supraventricular tachyarrhythmia of atrial septal origin by comparing the morphological features to a set of predetermined ventricular tachyarrhythmia template morphological features.

17. The system of claim 13, further comprising a plurality of electrodes and one or more leads coupled to the sensing circuit, the plurality of electrodes incorporated into the one or more leads and including:

a right atrial electrode configured to sense a right atrial electrogram;

a left atrial electrode configured to sense a left atrial electrogram;

an atrial septal electrode configured to sense an atrial septal electrogram; and

a ventricular electrode configured to sense the ventricular electrogram.

18. The system of claim 17, wherein the one or more leads comprise one lead including the right atrial electrode, the left atrial electrode, the atrial septal electrode, and the ventricular electrode.

19. The system of claim 17, wherein the one or more leads comprises a first lead including at least the right atrial electrode and a second lead including at least the left atrial electrode.

20. A system, coupled to a heart having a right atrium (RA) connected to a superior vena cava, a left atrium (LA), a sinoatrial (SA) node, a coronary sinus, and a coronary vein, for monitoring prognostic factors for atrial fibrillation and heart failure, the system comprising:

a first electrode configured for placement in the RA or superior vena cava near the SA node to sense an RA electrogram indicative of cardiac depolarizations in an upper RA region including the SA node;

a second electrode configured for placement in the coronary sinus or coronary vein near the LA to sense an LA electrogram indicative of cardiac depolarizations in the LA;

a sensing circuit coupled to the first electrode to sense the RA electrogram and coupled to the second electrode to sense the LA electrogram; and

an inter-atrial interval monitoring circuit configured to detect one or more of atrial enlargement and atrial conduction disturbance using an inter-atrial interval, the inter-atrial interval monitoring circuit including;

an event detection circuit, coupled to the sensing circuit, to detect an RA event from the RA electrogram and an LA event from the LA electrogram during an atrial depolarization; and

an inter-atrial interval measurement circuit, coupled to the event detection circuit, to measure the inter-atrial interval being a time interval between the RA event and the LA event.

21. The system of claim 20, further including a first lead coupled to the sensing circuit, wherein the first electrode and the second electrode are incorporated into the first lead.

22. The system of claim 20, further including a first lead coupled to the sensing circuit and a second lead coupled to the sensing circuit, wherein the first electrode is incorporated into the first lead, and the second electrode is incorporated into the second lead.

23. The system of claim 20, wherein the inter-atrial interval monitoring circuit comprises an atrial enlargement detection circuit coupled to the inter-atrial interval measurement circuit, the atrial enlargement detection circuit configured to detect an abnormal enlargement of at least one atrium using the inter-atrial interval.

24. The system of claim 23, wherein the atrial enlargement detection circuit comprises a comparator including a first input to receive the inter-atrial interval, a second input to receive a predetermined threshold interval, and an output to indicate the abnormal enlargement of at least one atrium when the inter-atrial interval exceeds the predetermined threshold interval.

25. The system of claim 20, wherein the inter-atrial interval monitoring circuit comprises an atrial conduction disturbance detection circuit coupled to the inter-atrial interval measurement circuit, the atrial conduction disturbance detection circuit configured to detect a variance of the inter-atrial interval.

26. The system of claim 25, wherein the atrial conduction disturbance detection circuit comprises a comparator including a first input to receive the variance of the inter-atrial interval, a second input to receive a predetermined threshold variance, and an output to indicate the atrial conduction disturbance when the variance of the inter-atrial interval exceeds the predetermined threshold variance.

27. The system of claim 20, wherein the inter-atrial interval monitoring circuit comprises a therapy monitoring circuit to monitor an effect of a therapy using the inter-atrial interval.

28. A method for classifying a tachyarrhythmia by origin, comprising:

receiving an atrial activation sequence indicative of an order of occurrence of a right atrial (RA) event, an atrial septal event, and an left atrial (LA) event during an atrial depolarization;

classifying the tachyarrhythmia as a tachyarrhythmia of RA origin if the RA event occurs first in the atrial activation sequence;

classifying the tachyarrhythmia as a tachyarrhythmia of LA origin if the LA event occurs first in the atrial activation sequence; and

classifying the tachyarrhythmia as a tachyarrhythmia of atrial septal or ventricular origin if the atrial septal event occurs first in the atrial activation sequence.

29. The method of claim 28, further comprising:

receiving arrhythmic morphological parameters measured from one or more cardiac signals indicative of the tachyarrhythmia; and

classifying the tachyarrhythmia as one of a tachyarrhythmia of atrial septal origin and a tachyarrhythmia of ventricular origin using the arrhythmia morphological parameters.

30. The method of claim 29, wherein classifying the tachyarrhythmia as one of the tachyarrhythmia of atrial septal origin and the tachyarrhythmia of ventricular origin using the arrhythmia morphological parameters comprises:

comparing the arrhythmia morphological parameters to template ventricular tachyarrhythmia morphological parameters; and

classifying the tachyarrhythmia as the tachyarrhythmia of ventricular origin if the arrhythmia morphological parameters match the template ventricular tachyarrhythmia morphological parameters.

31. The method of claim 30, wherein classifying the tachyarrhythmia as one of the tachyarrhythmia of atrial septal origin and the tachyarrhythmia of ventricular origin using the arrhythmia morphological parameters further comprises classifying the tachyarrhythmia as the tachyarrhythmia of atrial septal origin if the arrhythmia morphological parameters do not match the template ventricular tachyarrhythmia morphological parameters.

32. A method for detecting and classifying tachyarrhythmia in a heart having a right atrium (RA), a left atrium (LA), a left ventricle (LV), a sinoatrial (SA) node, and an atrial septum, the method comprising:

sensing a plurality of atrial electrograms indicative of regional depolarizations in a plurality of substantially different atrial locations and at least one ventricular electrogram;

detecting an atrial rate from at least one atrial electrogram of the plurality of atrial electrograms and a ventricular rate from the at least one ventricular electrogram;

detecting a tachyarrhythmia using at least one of the atrial rate and the ventricular rate;

classifying the detected tachyarrhythmia as a 1;

1 tachyarrhythmia when the atrial rate and the ventricular rate are substantially equal;

mapping an atrial activation sequence using the plurality of atrial electrograms, the atrial activation sequence indicative of an order of occurrence of regional depolarizations in the plurality of substantially different atrial locations during an atrial depolarization; and

classifying the 1;

1 tachyarrhythmia using the atrial activation sequence.

33. The method of claim 32, wherein sensing the plurality of atrial electrograms comprises:

sensing an RA electrogram from a location near the SA node;

sensing an LA electrogram from a location near the LA; and

sensing an atrial septal electrogram from a location in or near the atrial septum.

34. The method of claim 33, wherein classifying the 1:

1 tachyarrhythmia comprises comparing the atrial activation sequence to a plurality of predetermined template sequences.

35. The method of claim 34, wherein classifying the 1:

1 tachyarrhythmia comprises classifying the 1;

1 tachyarrhythmia as a supraventricular tachyarrhythmia of RA origin if the atrial activation sequence approximately matches a predetermined RA pattern template sequence.

36. The method of claim 34, wherein classifying the 1:

1 tachyarrhythmia comprises classifying the 1;

1 tachyarrhythmia as a supraventricular tachyarrhythmia of LA origin if the atrial activation sequence approximately matches a predetermined LA pattern template sequence.

37. The method of claim 34, wherein classifying the 1:

1 tachyarrhythmia comprises classifying the 1;

1 tachyarrhythmia as a supraventricular tachyarrhythmia of atrial septal origin or a ventricular tachyarrhythmia if the atrial activation sequence approximately matches a predetermined atrial septal pattern template sequence.

38. The method of claim 37, wherein classifying the 1:

1 tachyarrhythmia further comprises classifying the 1;

1 tachyarrhythmia using arrhythmia morphological features extracted from one or more signals selected from the plurality of atrial electrogram and the at least one ventricular electrogram sensed during the detected 1;

1 tachyarrhythmia.

39. The method of claim 38, wherein classifying the 1:

1 tachyarrhythmia further comprises discriminating the ventricular tachyarrhythmia from the supraventricular tachyarrhythmia of atrial septal origin by comparing the arrhythmia morphological features to predetermined ventricular tachyarrhythmia template morphological features.

40. The method of claim 34, wherein classifying the 1:

1 tachyarrhythmia comprises classifying the 1;

1 tachyarrhythmia as a supraventricular tachyarrhythmia of atrial septal origin or a ventricular tachyarrhythmia if the atrial activation sequence approximately matches neither the predetermined RA pattern template sequence nor the predetermined LA pattern template sequence.

41. A method for monitoring a heart having a right atrium (RA) connected to a superior vena cava, a left atrium (LA), a sinoatrial (SA) node, an atrial septum, a coronary sinus, and a coronary vein, the method comprising:

sensing an RA electrogram using an electrode placed in the RA or the superior vena cava near the SA node, the RA electrogram indicative of cardiac depolarizations in an upper RA region including the SA node;

sensing an LA electrogram using an electrode placed in the coronary sinus or coronary vein near the LA, the LA electrogram indicative of cardiac depolarizations in the LA;

detecting an RA event from the RA electrogram and an LA event from the LA electrogram for each atrial depolarization;

measuring an inter-atrial interval between the RA event and the LA event;

detecting one or more of atrial enlargement and atrial conduction disturbance using the measured inter-atrial interval.

42. The method of claim 41, further comprising prognosticating at least one of atrial fibrillation and heart failure using at least the measured inter-atrial interval.

43. The method of claim 41, farther comprising:

delivering a therapy; and

monitoring an effect of the therapy using the inter-atrial interval.

44. The method of claim 41, comprising detecting an abnormal enlargement of at least one of the RA and the LA using the inter-atrial interval.

45. The method of claim 44, wherein detecting the abnormal enlargement of at least one of the RA and the LA comprises:

comparing the inter-atrial interval to a predetermined threshold interval; and

indicating the abnormal enlargement of at least one atrium when the inter-atrial interval exceeds the predetermined threshold interval.

46. The method of claim 41, comprising detecting the atrial conduction disturbance using the inter-atrial interval and a threshold.

47. The method of claim 46, wherein detecting the atrial conduction disturbance comprises:

measuring a variance of the inter-atrial interval;

comparing the variance of the inter-atrial interval to a predetermined threshold variance; and

indicating an atrial conduction disturbance when the variance of the inter-atrial interval exceeds the predetermined threshold variance.