# US 2019/0168003 A1 · Method and device for managing a self-termination period for ventricular arrhythmias

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- Number: US 2019/0168003 A1
- Document ID: US20190168003A1
- Status: Published application
- Kind: A1
- Application number: 15/829,269
- Filed: 2017-12-01
- Published: 2019-06-06
- Earliest claimed: 2017-12-01
- Assignees: Pacesetter, Inc.
- Applicants: Pacesetter, Inc.
- Inventors: Xing Pei
- Web page: https://patentgrep.com/patent/US20190168003A1

## CPC

- A61N 1/36514: {controlled by a physiological quantity other than heart potential, e.g. blood pressure (controlled by two or more physical parameters A61N1/36585)}
- A61B 5/346: Analysis of electrocardiograms
- A61B 5/361: Detecting fibrillation
- A61B 5/363: Detecting tachycardia or bradycardia
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61B 5/686: {Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence)}
- A61N 1/3621: {for treating or preventing abnormally high heart rate}
- A61N 1/36592: {controlled by the heart rate variability}
- A61N 1/3925: {Monitoring; Protecting}
- A61N 1/3956: {Implantable devices for applying electric shocks to the heart, e.g. for cardioversion}
- A61N 1/3987: {characterised by the timing or triggering of the shock}
- G16H 20/10: relating to drugs or medications, e.g. for ensuring correct administration to patients
- G16H 40/63: for local operation
- G16H 50/20: for computer-aided diagnosis, e.g. based on medical expert systems
- A61B 5/0006: {ECG or EEG signals}
- A61B 5/0031: {Implanted circuitry}
- A61N 1/025: {Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors}
- A61N 1/0587: {Epicardial electrode systems; Endocardial electrodes piercing the pericardium}
- A61N 1/3605: {Implantable neurostimulators for stimulating central or peripheral nerve system}
- A61N 1/3622: {comprising two or more electrodes co-operating with different heart regions}
- A61N 1/3706: {Pacemaker parameters (stimulation threshold A61N1/371)}
- A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators}
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA

## Abstract

Methods and devices are provided for sensing cardiac events from electrodes located proximate to one or more atrial or ventricular sites, over a period of time that includes a detection period followed by an observation period. One or more processors declare a ventricular arrhythmia episode and a corresponding VT/VF therapy based on the cardiac events during at least the detection period. The processors delay delivery of the VT/VF therapy for a self-termination period within the observation period. The self-termination period represents a time period during which the ventricular arrhythmia episode may self-terminate. The processors analyze a stability characteristic of interest (COI) from the cardiac events sensed over at least a portion the observation period and determine an end point for the self-termination period, within the observation period, based on the stability COI. The VT/VF therapy is delivered when the VT/VF arrhythmia episode continues past the end point.

## Claims

### Claim 1

A method, comprising:
sensing cardiac events, from electrodes located proximate to one or more atrial or ventricular sites, over a period of time that includes a detection period followed by an observation period;
utilizing one or more processors to perform:
declaring a ventricular arrhythmia episode and a corresponding VT/VF therapy based on the cardiac events during at least the detection period;
delaying delivery of the VT/VF therapy for a self-termination period within the observation period, the self-termination period representing a time period during which the ventricular arrhythmia episode may self-terminate;
analyzing a stability characteristic of interest (COI) from the cardiac events sensed over at least a portion the observation period;
determining an end point for the self-termination period, within the observation period, based on the stability COI; and
delivering the VT/VF therapy when the VT/VF arrhythmia episode continues past the end point.

### Claim 2 (depends on 1)

The method of claim 1, wherein the analyzing and determining operations occur in response to the declaring of the VT therapy and after the delaying delivery of the VT therapy.

### Claim 3 (depends on 1)

The method of claim 1, wherein the analyzing operation further comprises detecting tachycardia events from the cardiac events, measuring amplitudes of the tachycardia events, and analyzing the stability COI based on the amplitudes.

### Claim 4 (depends on 3)

The method of claim 3, wherein the analyzing operation further comprises calculating the stability COI based on at least one of a mean or variance of the amplitudes.

### Claim 5 (depends on 1)

The method of claim 1, wherein the analyzing operation further comprises detecting tachycardia events from the cardiac events, measuring rates between the tachycardia events, and analyzing the stability COI based on the rates.

### Claim 6 (depends on 5)

The method of claim 5, wherein the analyzing operation further comprises calculating the stability COI based on at least one of a mean or variance of the rates.

### Claim 7 (depends on 1)

The method of claim 1, wherein the determining operation ends the self-termination period when the stability COI exhibits increasing rate instability and initiates an operation to deliver the VT/VF therapy.

### Claim 8 (depends on 1)

The method of claim 1, wherein the stability COI represents a degree of variation in at least one of an amplitude or rate of the tachycardia events, the analyzing operation declaring the tachycardia events to be stable or unstable based on the stability COI.

### Claim 9 (depends on 8)

The method of claim 8, wherein, when the stability CO is declared stable, the determining operation sets the end point based on a predetermined maximum duration for the self-termination period before delivering the VT/VF therapy.

### Claim 10 (depends on 8)

The method of claim 8, wherein the stability COI is declared unstable when the degree of variation corresponds to a rate variation that exceeds a rate threshold, the method further comprising determining whether the rate variation represents increasing or decreasing rate instability, the determining operation setting the end point based on a predetermined maximum duration for the self-termination period before delivering the VT/VF therapy when the stability COI exhibits the decreasing rate instability.

### Claim 11 (depends on 8)

The method of claim 8, wherein the stability COI is declared unstable when the stability COI indicates the degree of variation in the amplitude exceeds an amplitude threshold, the method further comprising determining whether the amplitude exhibits increasing or decreasing amplitude instability, wherein the determining operation designating the end point for the self-termination period when the stability COI exhibits the increasing amplitude instability and initiates an operation to deliver the VT/VF therapy.

### Claim 12 (depends on 1)

The method of claim 1, wherein the analyzing operation determines whether the stability COI is stable or unstable and increasing or decreasing, the determining operation designating a first end point for the self-termination period when the stability COI exhibits an unstable and decreasing rate in combination with an unstable amplitude.

### Claim 13 (depends on 1)

The method of claim 1, further comprising maintaining an arrhythmia self-termination log that is utilized in connection with a self learning process to recognize certain types of arrhythmias as either self-terminating or non-self-terminating.

### Claim 14

An implantable medical device, comprising:
electrodes configured to be located proximate to one or more atrial or ventricular sites, the electrodes configured to sense cardiac events over a period of time that includes a detection period followed by an observation period;
memory to store program instructions; and
one or more processors that, when executing the program instructions:
declare a ventricular arrhythmia episode and a corresponding VT therapy based on the cardiac events during at least the detection period;
delay delivery of the VT therapy for a self-termination period within the observation period, the self-termination period representing a time period during which the ventricular arrhythmia episode may self-terminate;
analyze a stability characteristic of interest (COI) from the cardiac events sensed over at least a portion the observation period;
determine an end point for the self-termination period, within the observation period, based on the stability COI; and
deliver the VT/VF therapy when the VT/VF arrhythmia episode continues past the end point.

### Claim 15 (depends on 14)

The device of claim 14, wherein the one or more processors are configured to perform the analyze and determine operations occur in response to the declaring of the VT/VF therapy and after the delaying delivery of the VT/VF therapy.

### Claim 16 (depends on 14)

The device of claim 14, wherein the one or more processors are further configured to detect tachycardia events from the cardiac events, measure amplitudes of the tachycardia events, and analyze the stability COI based on the amplitudes.

### Claim 17 (depends on 14)

The device of claim 14, wherein the one or more processors are further configured to calculate the stability COI based on at least one of a mean or variance of the amplitudes.

### Claim 18 (depends on 14)

The device of claim 14, wherein the one or more processors are further configured to detect tachycardia events from the cardiac events, measure rates between the tachycardia events, and analyze the stability COI based on the rates.

### Claim 19 (depends on 14)

The device of claim 14, wherein the one or more processors are configured to determine whether past and current ventricular arrhythmia episodes are similar and based thereon declaring the current ventricular arrhythmia episode to be self-terminating.

### Claim 20 (depends on 19)

The device of claim 19, wherein the one or more processors adjust a duration of the observation period based on whether the current ventricular arrhythmia episode is declared to be self-terminating.