Method and medical device for discriminating between a supraventricular tachycardia and a ventricular tachycardia

Patent metadata

Field	Value
Publication number	US-2018132745-A1
Application number	US-201515567735-A
Country	US
Kind code	A1
Filing date	Apr 20, 2015
Priority date	Apr 20, 2015
Publication date	May 17, 2018
Grant date	—

Abstract

A method for automatically discriminating between a supraventricular tachycardia event and a ventricular tachycardia event is provided. The method includes sensing a first cardiac signal using a first electrode pair and a second cardiac signal using a second electrode pair during a heartbeat, applying a first algorithm to the first cardiac signal to determine whether the first cardiac signal is indicative for a supraventricular tachycardia or indicative for the ventricular tachycardia; applying a second algorithm to the second cardiac signal to determine whether the second cardiac signal is indicative for the supraventricular tachycardia or indicative for the ventricular tachycardia, the second comparison algorithm being different from the first comparison algorithm; and assigning to a heartbeat-specific indicator a first value indicative for the ventricular tachycardia when at least one of the first cardiac signal and the second cardiac signal have been determined to be indicative tor the ventricular tachycardia.

First claim

1 . A method for automatically discriminating between a supraventricular tachycardia event and a ventricular tachycardia event, the method comprising:
sensing a first cardiac signal using a first electrode pair during a heartbeat and sensing a second cardiac signal using a second electrode pair during the heartbeat, the second electrode pair having a different distance between its electrodes than the first electrode pair; applying a first comparison algorithm to the first cardiac signal to determine whether the first cardiac signal is indicative for a supraventricular tachycardia or indicative for a ventricular tachycardia; applying a second comparison algorithm to the second cardiac signal to determine whether the second cardiac signal is indicative for the supraventricular tachycardia or indicative for the ventricular tachycardia, the second comparison algorithm being different from the first comparison algorithm; and classifying the heartbeat as being indicative for the ventricular tachycardia when at least one of the first cardiac signal and the second cardiac signal is determined to be indicative for the ventricular tachycardia.

2 . The method of claim 1 , wherein the first comparison algorithm uses a first template, and wherein the second comparison algorithm uses a second template different from the first template.

3 . The method of claim 1 , wherein the first comparison algorithm is configured to determine more heartbeat-specific morphology parameters than the second comparison algorithm.

4 . The method of claim 2 , wherein the first comparison algorithm is configured to compare the first cardiac signal to the first template to identify changes of first heartbeat-specific morphology parameters referring to negative waves and to positive waves, and wherein the second comparison algorithm is configured to compare the second cardiac signal to the second template to identify changes of second heartbeat-specific morphology parameters referring to negative waves only.

5 . The method of claim 1 , wherein each of the first comparison algorithm and the second comparison algorithm is configured to determine at least two heartbeat-specific morphology parameters.

6 . The method of any of claim 1 , comprising assigning to a heartbeat-specific indicator a first value indicative for the ventricular tachycardia when the heartbeat is classified as being indicative for the ventricular tachycardia.

7 . The method of claim 6 , wherein the first value is assigned to the heartbeat-specific indicator when at least one of the changes of the first heartbeat-specific morphology parameters and/or at least one of the changes of the second heartbeat-specific morphology parameters is indicative for the ventricular tachycardia, and/or wherein a second value indicative for a supraventricular tachycardia is assigned to the heartbeat-specific indicator when none of the changes of the first heartbeat-specific morphology parameters and none of the changes of the second heartbeat-specific morphology parameters is indicative for the ventricular tachycardia.

8 . The method of claim 6 , wherein the first comparison algorithm is configured to compare the first cardiac signal to a template to identify a change of a first Q-wave parameter, a change of a first R-wave parameter, and/or a change of a first S-wave parameter as respective first heartbeat-specific indicators.

9 . The method of claim 8 , wherein the first comparison algorithm is configured to identify the change of the first Q-wave parameter, the change of the first R-wave parameter, and the change of the first S-wave parameter in this order.

10 . The method of claim 8 , wherein the first comparison algorithm is configured to identify changes of several first Q-wave parameters, changes of several first R-wave parameters, and/or changes of the several S-wave parameters as respective first heartbeat-specific indicators.

11 . The method of claim 1 , wherein the first cardiac signal corresponds to a far-field signal of the heartbeat, and/or wherein the first comparison algorithm is configured to assign to a heartbeat-specific QRS-indicator a third value indicative for the ventricular tachycardia when at least one of the first heartbeat-specific indicators is indicative for the ventricular tachycardia, and/or wherein the first comparison algorithm is configured to assign to the heartbeat-specific QRS-indicator a fourth value indicative for a supraventricular tachycardia when none of the first heartbeat-specific indicators is indicative for the ventricular tachycardia.

12 . The method of the claim 11 , wherein the third value is assigned to the heartbeat-specific QRS-indicator when a number of Q-waves in the first cardiac signal differs from a number of Q-waves in a template, when a width of a Q-wave in the first cardiac signal is larger than a width of a Q-wave in the template by at least about 30%, when the width of the Q-wave in the first cardiac signal is smaller than the width of the Q-wave in the template by at least about 20%, when an amplitude of the Q-wave in the first cardiac signal is larger than an amplitude of the Q-wave in the template by at least about 30% and when a difference between an amplitude of an R-wave in the first cardiac signal differs from an amplitude of an R-wave in the template by less than about 10%, and/or when the amplitude of the Q-wave in the first cardiac signal is smaller than the amplitude of the Q-wave in the template by at least about 30%.

13 . The method of claim 11 , wherein the third value is assigned to the heartbeat-specific QRS-indicator when a splitting of an R-wave in the first cardiac signal differs from a splitting of an R-wave in a template, when a notching of the R-wave in the first cardiac signal differs from a notching of the R-wave in the template, when a width of the R-wave in the first cardiac signal is larger than a width of the R-wave in the first template by at least about 20%, when the width of the R-wave in the first cardiac signal is increased by at least about 12 milliseconds (ms) compared to the width of the R-wave in the cardiac template or an averaged width of R-waves during normal heartbeats, and/or when the amplitude of the R-wave in the first cardiac signal is smaller than the amplitude of the R-wave in the template by at least about 30%.

14 . The method of claim 11 , wherein the third value indicative for the ventricular tachycardia is assigned to the heartbeat-specific QRS-indicator when a number of S-waves in the first cardiac signal differs from a number of S-waves in a template.

15 . The method of claim 2 , wherein the second comparison algorithm is configured to compare the second cardiac signal to the second template to identify a change of an S-wave morphology parameter as a second heartbeat-specific indicator.

16 . The method of claim 15 , wherein the second comparison algorithm is configured to identify changes of several S-wave morphology parameters as second heartbeat-specific indicators.

17 . The method of claim 1 , wherein the second cardiac signal corresponds to a near-field signal of the heartbeat, and/or wherein the second comparison algorithm is configured to assign to a heartbeat-specific S-indicator a third value when at least one of the second heartbeat-specific morphology parameters is indicative for the ventricular tachycardia, and/or wherein the second comparison algorithm is configured to assign to the heartbeat-specific S-indicator a fourth value when none of the second heartbeat-specific morphology parameters is indicative for the ventricular tachycardia.

Assignees

• Medtronic Inc

Inventors

• Himmrich Ewald

Classifications

• A61B5/7264

  Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems · CPC title

• A61N1/3624

  occurring in the atrium, i.e. atrial tachycardia · CPC title

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• A61N1/3622

  comprising two or more electrodes co-operating with different heart regions · CPC title

• A61B5/6869

  Heart · CPC title