METHOD AND APPARATUS FOR DETECTING AND TREATING TACHYARRHYTHMIAS INCORPORATING DIAGNOSTIC/THERAPEUTIC PACING TECHNIQUES

• US 20090259269A1
• Filed: 04/09/2008
• Published: 10/15/2009
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Brown, Mark L.
• Granted Patent: US 8,706,220 B2
• Time in Patent Office: Days
• US Class Current: 607/14
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• 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 1/39622 Pacing therapy
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

An implantable medical device (IMD) and methods of operating the same to treat a tachyarrhythmia are disclosed herein. In accordance with this method, an arrhythmia of the heart is classified based on one or more supraventricular tachycardia (SVT) rejection rules, which differentiate between a first group of heart rhythms that do not require treatment and a second group of heart rhythms that possibly require treatment. Diagnostic/therapeutic pacing can then be performed to further discriminate the second group of heart rhythms as being within a first sub-group of heart rhythms and a second sub-group of heart rhythms which are to be treated by applying a ventricular tachycardia (VT)/ventricular fibrillation (VF) therapy sequence. In another implementation, the order in which the IMD performs diagnostic/therapeutic pacing and analyzes passive detection and classification criteria can be reversed.

Claims

1. A method for operating an implantable medical device (IMD) to treat a tachyarrhythmia in a heart including an atrium and a ventricle, the method comprising:

classifying an arrhythmia of the heart based on one or more supraventricular tachycardia (SVT) rejection rules, wherein at least some of the SVT rejection rules differentiate between a first group of heart rhythms that do not require treatment and a second group of heart rhythms that possibly require treatment; and

performing diagnostic/therapeutic pacing to further discriminate the second group of heart rhythms as being within a first sub-group of heart rhythms and a second sub-group of heart rhythms which are to be treated by applying a ventricular tachycardia (VT)/ventricular fibrillation (VF) therapy sequence.

2. A method according to claim 1, wherein the first group of heart rhythms that do not require treatment comprise:

an atrial fibrillation (AF) type heart rhythm, a AV nodal reentrant tachycardia (AVNRT) type heart rhythm, and a Sinus Tachycardia (ST) type heart rhythm, the second group of heart rhythms that possibly require treatment comprise;

an atrial tachycardia (AT) type heart rhythm, a supraventricular tachycardia (SVT) type heart rhythm, a ventricular tachycardia (VT) type heart rhythm, and a ventricular fibrillation (VF) type heart rhythm, wherein the first sub-group of heart rhythms comprise;

atrial tachycardia (AT) type heart rhythms and supraventricular tachycardia (SVT) type heart rhythms, and wherein the second sub-group of heart rhythms comprise;

ventricular tachycardia (VT) type heart rhythms and ventricular fibrillation (VF) type heart rhythms.

3. A method according to claim 1, further comprising:

applying the VT/VF therapy sequence to at least one of the atrium and the ventricle when one of the second sub-group of heart rhythms is detected based on the diagnostic/therapeutic pacing.

4. A method according to claim 1, wherein the step of performing diagnostic/therapeutic pacing to further distinguish between a first sub-group of heart rhythms and a second sub-group of heart rhythms which are to be treated by applying a ventricular tachycardia (VT)/ventricular fibrillation (VF) therapy sequence, comprises:

determining whether the heart rhythm exhibits a pattern that requires a VT/VF therapy sequence;

applying a diagnostic/therapeutic pacing sequence when the heart rhythm exhibits a pattern that do not require a VT/VF therapy sequence; and

determining the response of the heart to the diagnostic/therapeutic pacing sequence.

5. A method according to claim 4, wherein the step of determining whether the heart rhythm exhibits a pattern that requires a VT/VF therapy sequence, comprises:

determining whether the heart rhythm exhibits a pattern of atrial events and ventricular events that requires a VT/VF therapy sequence.

6. A method according to claim 5, wherein the step of determining whether the heart rhythm exhibits a pattern of atrial events and ventricular events that requires a VT/VF therapy sequence, comprises:

determining the heart rhythm exhibits a pattern of atrial events and ventricular events that requires a VT/VF therapy sequence based on whether the number of atrial events is;

greater than the number of ventricular events,

substantially equal to the number of ventricular events, or

less than the number of ventricular events.

7. A method according to claim 4, wherein the step of applying a diagnostic/therapeutic pacing sequence when the heart rhythm exhibits a pattern that do not require a VT/VF therapy sequence, further comprises:

applying a diagnostic/therapeutic pacing sequence to at least one of the atrium and the ventricle when the heart rhythm exhibits a pattern that do not require a VT/VF therapy sequence.

8. A method according to claim 7, wherein the diagnostic/therapeutic pacing sequence is applied to at least one of the atrium and the ventricle to control the heart rhythm to aid in discriminating between the first sub-group of heart rhythms and the second sub-group of heart rhythms.

9. A method according to claim 4, wherein the step of determining the response of the heart to the diagnostic/therapeutic pacing sequence further comprises:

determining whether the diagnostic/therapeutic pacing sequence terminated the tachyarrhythmia; and

determining whether the heart rhythm is indicative of a supraventricular tachycardia (SVT) type rhythm or a ventricular tachycardia (VT) type rhythm if the diagnostic/therapeutic pacing sequence did not terminate the tachyarrhythmia.

10. A method according to claim 9, further comprising:

performing normal rhythm processing when the heart rhythm following the diagnostic/therapeutic pacing sequence indicates that the diagnostic/therapeutic pacing sequence has terminated the tachyarrhythmia;

waiting for a trigger event when the heart rhythm is indicative of a supraventricular tachycardia (SVT) type rhythm, wherein the trigger event indicates that the heart rhythm as originally diagnosed based on diagnostic/therapeutic pacing has changed and is to be re-evaluated;

applying a VT/VF therapy sequence when the heart rhythm is indicative of a ventricular tachycardia (VT) type rhythm; and

performing normal rhythm processing once the VT/VF therapy sequence is complete.

11. A method according to claim 1, wherein the VT/VF therapy sequence is applied to at least one of the atrium and the ventricle when one of the second sub-group of heart rhythms is detected based on the diagnostic/therapeutic pacing to terminate a tachycardia.

12. An implantable medical device (IMD) designed to treat a tachyarrhythmia in a heart, the IMD comprising:

a processor configured to;

classify an arrhythmia of the heart based on one or more SVT rejection rules, wherein at least some of the SVT rejection rules differentiate between a first group of heart rhythms that do not require treatment and a second group of heart rhythms that possibly require treatment; and

perform diagnostic/therapeutic pacing to further discriminate the second group of heart rhythms as being within a first sub-group of heart rhythms and a second sub-group of heart rhythms which are to be treated by applying a ventricular tachycardia (VT)/ventricular fibrillation (VF) therapy sequence.

13. An implantable medical device according to claim 12, wherein the first group of heart rhythms that do not require treatment comprise:

an atrial fibrillation (AF) type heart rhythm, a AV nodal reentrant tachycardia (AVNRT) type heart rhythm, and a Sinus Tachycardia (ST) type heart rhythm, and

wherein the second group of heart rhythms that possibly require treatment comprise;

an atrial tachycardia (AT) type heart rhythm, a supraventricular tachycardia (SVT) type heart rhythm, a ventricular tachycardia (VT) type heart rhythm, and a ventricular fibrillation (VF) type heart rhythm, wherein the first sub-group of heart rhythms comprise;

atrial tachycardia (AT) type heart rhythms and supraventricular tachycardia (SVT) type heart rhythms, and wherein the second sub-group of heart rhythms comprise;

ventricular tachycardia (VT) type heart rhythms and ventricular fibrillation (VF) type heart rhythms.

14. An implantable medical device according to claim 12, further comprising:

a first lead implanted into a ventricle of the heart;

a second lead implanted into an atrium of the heart;

a therapy module, coupled to the processor, the first lead and the second lead, wherein the therapy module is designed to deliver a ventricular tachycardia (VT)/ventricular fibrillation (VF) therapy sequence of electrical pulses to at least one of the ventricle via the first lead or the atrium via the second lead, when the processor detects one of the second sub-group of heart rhythms based on the diagnostic/therapeutic pacing based on the diagnostic/therapeutic pacing.

15. An implantable medical device according to claim 14, wherein the processor, when performing diagnostic/therapeutic pacing, is further configured to determine whether the heart rhythm exhibits a pattern of atrial events and ventricular events that requires a VT/VF therapy sequence based on whether the number of atrial events is:

greater than the number of ventricular events,

substantially equal to the number of ventricular events, or

less than the number of ventricular events.

16. An implantable medical device according to claim 15, wherein the diagnostic/therapeutic pacing sequence is applied to at least one of the atrium and the ventricle to control the heart rhythm to aid in discriminating between the first sub-group of heart rhythms and the second sub-group of heart rhythms.

17. An implantable medical device according to claim 16, wherein the processor, when performing diagnostic/therapeutic pacing, is further configured to determine the response of the heart to the diagnostic/therapeutic pacing sequence.

18. An implantable medical device according to claim 17, wherein the processor is further configured to perform normal rhythm processing when the heart rhythm following the diagnostic/therapeutic pacing sequence indicates that the diagnostic/therapeutic pacing sequence has terminated the tachyarrhythmia.

19. An implantable medical device according to claim 17, wherein the processor is further designed to wait for a trigger event when the heart rhythm in response to the diagnostic/therapeutic pacing sequence is indicative of a supraventricular tachycardia (SVT) type rhythm, wherein the trigger event indicates that the heart rhythm as originally diagnosed based on diagnostic/therapeutic pacing has changed and is to be re-evaluated.

20. An implantable medical device according to claim 17, wherein the processor is further designed to instruct the therapy module to apply a VT/VF therapy sequence when the heart rhythm in response to the diagnostic/therapeutic pacing sequence is indicative of a ventricular tachycardia (VT) type rhythm.