# US 9,433,791 B2 · AV nodal stimulation during atrial tachyarrhythmia to prevent inappropriate therapy delivery

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,433,791 B2
- Document ID: US9433791B2
- Status: Granted
- Kind: B2
- Application number: 13/105,689
- Filed: 2011-05-11
- Published: 2012-11-15
- Granted: 2016-09-06
- Earliest claimed: 2011-05-11
- Assignees: Medtronic, Inc.
- Applicants: Eduardo N. Warman; John E. Burnes; Koen J. Michels; Paul D. Ziegler; Lilian Kornet
- Inventors: Eduardo N. Warman; John E. Burnes; Koen J. Michels; Paul D. Ziegler; Lilian Kornet
- Web page: https://patentgrep.com/patent/US9433791B2

## CPC

- A61N 1/3622: {comprising two or more electrodes co-operating with different heart regions}
- A61N 1/36114: {Cardiac control, e.g. by vagal stimulation (stimulating the heart A61N1/362)}
- A61N 1/3621: {for treating or preventing abnormally high heart rate}
- A61N 1/3624: {occurring in the atrium, i.e. atrial tachycardia}
- A61N 1/36053: {adapted for vagal stimulation (A61N1/36114 takes precedence)}
- 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)

## Abstract

The disclosure describes techniques for delivering electrical stimulation to decrease the ventricular rate response during an atrial tachyarrhythmia, such as atrial fibrillation. AV nodal stimulation is employed during an atrial tachyarrhythmia episode with rapid ventricular conduction to distinguish ventricular tachyarrhythmia from supraventricular tachycardia and thereby prevent delivering inappropriate therapy to a patient.

## Claims

### Claim 1

A method comprising:
incrementing a counter upon detection of a ventricular tachyarrhythmia event;
detecting an atrial tachyarrhythmia;
during the detected atrial tachyarrhythmia, anticipating detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
in response to anticipating detection of the ventricular tachyarrhythmia, delivering electrical stimulation to block the atrioventricular node of the heart; and
terminating the delivery of electrical stimulation based on one or more stimulation termination criteria.

### Claim 2 (depends on 1)

The method of claim 1, further comprising establishing a stimulation time period wherein the electrical stimulation is delivered, the established stimulation time period based on a sense time period over which ventricular depolarizations can be sensed between one or more pulse of the electrical stimulation,
the established stimulation time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 3 (depends on 2)

The method of claim 2, further comprising determining the sense time period based on an R-R interval of the heart of the patient.

### Claim 4 (depends on 3)

The method of claim 3, wherein determining the sense time period based on an R-R interval of the heart of the patient comprises:
measuring a plurality of R-R intervals for the heart of the patient;
calculating a median R-R interval from the measured R-R intervals; and
setting the sense time period to greater than or equal to a predetermined portion of the median R-R interval.

### Claim 5 (depends on 2)

The method of claim 2, further comprising delivering electrical stimulation to block the atrioventricular node of the heart regardless of the sense time period, before delivering electrical stimulation based on the sensed time period.

### Claim 6 (depends on 5)

The method of claim 5, wherein electrical stimulation is delivered regardless of the sense time period for a stimulation response time period.

### Claim 7 (depends on 1)

The method of claim 1, wherein the one or more stimulation termination criteria comprises at least one of expiration of an electrical stimulation delivery time period, an accumulation of blanking time periods exceeding a threshold percentage of an electrical stimulation delivery time period, failure to detect a threshold ventricular rate response within an electrical stimulation response time period, or detection of a ventricular tachyarrhythmia.

### Claim 8 (depends on 7)

The method of claim 7, wherein the threshold percentage of an electrical stimulation delivery time period comprises less than or equal to approximately 50% a sense time period.

### Claim 9 (depends on 1)

The method of claim 1, further comprising delivering the electrical stimulation via electrodes positioned in the right atrium.

### Claim 10 (depends on 1)

The method of claim 1, wherein anticipating detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count comprises anticipating detection, in response to detection of the atrial tachyarrhythmia, of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count.

### Claim 11

A method comprising:
incrementing a counter upon detection of a ventricular tachyarrhythmia event;
anticipating detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
determining a sense time period; and
in response to anticipating detection of the ventricular tachyarrhythmia, delivering electrical stimulation to block the atrioventricular node of the heart over an electrical stimulation delivery time period, wherein the electrical stimulation delivery time period is based on the sense time period over which ventricular depolarizations can be sensed during the electrical stimulation delivery time period, the stimulation time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 12 (depends on 11)

The method of claim 11, further comprising detecting an atrial tachyarrhythmia comprising at least one of atrial fibrillation or atrial tachycardia.

### Claim 13 (depends on 12)

The method of claim 12, wherein detecting an atrial tachyarrhythmia comprises:
detecting a P-P interval value for the heart of the patient that is less than a percentage threshold of an R-R interval value; and
analyzing a rhythm of the heart of the patient for indications of sinus tachycardia.

### Claim 14 (depends on 11)

The method of claim 11, wherein anticipating detection of a ventricular tachyarrhythmia is based at least on a threshold value of a ventricular tachyarrhythmia event count.

### Claim 15 (depends on 14)

The method of claim 14, wherein the ventricular tachyarrhythmia event count comprises a number of sensed ventricular intervals indicative of a ventricular tachyarrhythmia.

### Claim 16 (depends on 11)

The method of claim 11, wherein delivering electrical stimulation comprises delivering the electrical stimulation during a refractory period of the heart of the patient.

### Claim 17 (depends on 11)

The method of claim 11 further comprising confirming, prior to delivering electrical stimulation, that a median R-R interval for the heart of the patient is less than a maximum threshold ventricular contraction rate and greater than or equal to a minimum threshold ventricular contraction rate.

### Claim 18 (depends on 11)

The method of claim 11, further comprising determining the sense time period based on an R-R interval of the heart of the patient.

### Claim 19 (depends on 18)

The method of claim 18, wherein determining the sense time period based on an R-R interval of the heart of the patient comprises:
measuring a plurality of R-R intervals for the heart of the patient;
calculating a median R-R interval from the measured R-R intervals; and
setting the sense time period to greater than or equal to a predetermined portion of the median R-R interval.

### Claim 20 (depends on 11)

The method of claim 11, further comprising delivering electrical stimulation to block the atrioventricular node of the heart regardless of the sense time period, before delivering electrical stimulation based on the sensed time period.

### Claim 21 (depends on 20)

The method of claim 20, wherein electrical stimulation is delivered regardless of the sense time period for a stimulation response time period.

### Claim 22 (depends on 21)

The method of claim 21, wherein the stimulation response time period is equal to approximately 10 seconds.

### Claim 23 (depends on 21)

The method of claim 21, wherein the stimulation response time period is equal to a time required for the heart of the patient to beat in a range from approximately 5 to approximately 10 beats.

### Claim 24 (depends on 21)

The method of claim 21, wherein the stimulation response time period is equal to a time required for an approximately 20% reduction in the rate at which the heart of the patient contracts from a contraction rate of the heart when electrical stimulation delivered regardless of when the sense time period begins.

### Claim 25 (depends on 21)

The method of claim 21, wherein the stimulation response time period is equal to a time required for a 40 beats per minute (bpm) reduction in the rate at which the heart of the patient contracts when a contraction rate of the heart when electrical stimulation delivered regardless of when the sense time period begins is greater than or equal to approximately 180 bpm.

### Claim 26 (depends on 21)

The method of claim 21, wherein the stimulation response time period is equal to a time required for a 20 beats per minute (bpm) reduction in the rate at which the heart of the patient contracts when a contraction rate of the heart when electrical stimulation delivered regardless of when the sense time period begins is less than or equal to approximately 120 bpm.

### Claim 27 (depends on 11)

The method of claim 11, further comprising terminating the delivery of electrical stimulation based on one or more stimulation termination criteria, wherein the one or more stimulation termination criteria comprises at least one of expiration of an electrical stimulation delivery time period, an accumulation of blanking time periods exceeding a threshold percentage of the electrical stimulation delivery time period, failure to detect a threshold ventricular rate response within an electrical stimulation response time period, or detection of a ventricular tachyarrhythmia.

### Claim 28 (depends on 27)

The method of claim 27, wherein the threshold percentage of an electrical stimulation delivery time period comprises less than or equal to approximately 50% of the sense time period.

### Claim 29 (depends on 11)

The method of claim 11, further comprising detecting an atrial tachyarrhythmia, and wherein anticipating detection of the ventricular tachyarrhythmia in the heart of a patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count comprises anticipating, during the detected atrial tachyarrhythmia, detection of the ventricular tachyarrhythmia in the heart of the patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count.

### Claim 30

A system comprising:
a stimulation generator configured to deliver electrical stimulation to a patient; and
a processor configured to increment a counter upon detection of a ventricular tachyarrhythmia event, anticipate detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count, and in response to anticipating detection of the ventricular tachyarrhythmia, control the stimulation generator to deliver electrical stimulation to block the atrioventricular node of the heart over an electrical stimulation delivery time period,
wherein the processor determines a sense time period and establishes a stimulation time period based on the sense time period over which ventricular depolarizations can be sensed during the electrical stimulation delivery time period and controls the stimulation generator to deliver the electrical stimulation during the stimulation time period, the established stimulation time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 31 (depends on 30)

The system of claim 30, wherein the processor is configured to detect an atrial tachyarrhythmia comprising at least one of atrial fibrillation or atrial tachycardia.

### Claim 32 (depends on 31)

The system of claim 31, wherein the processor detecting an atrial tachyarrhythmia comprises:
detecting a P-P interval value for the heart of the patient that is less than a percentage threshold of an R-R interval value; and
analyzing a rhythm of the heart of the patient for indications of sinus tachycardia.

### Claim 33 (depends on 30)

The system of claim 30, wherein the processor is configured to anticipate a ventricular tachyarrhythmia based at least on a threshold value of a ventricular tachyarrhythmia event count.

### Claim 34 (depends on 33)

The system of claim 33, wherein the ventricular tachyarrhythmia event count comprises a number of sensed ventricular intervals indicative of a ventricular tachyarrhythmia.

### Claim 35 (depends on 30)

The system of claim 30, wherein the processor is configured to control the stimulation generator to deliver the electrical stimulation during a refractory period of the heart of the patient.

### Claim 36 (depends on 30)

The system of claim 30, wherein the processor is configured confirm, prior to controlling the stimulation generator to deliver electrical stimulation, that a median RR interval for the heart of the patient is less than a maximum threshold ventricular contraction rate and greater than or equal to a minimum threshold ventricular contraction rate.

### Claim 37 (depends on 30)

The system of claim 30, wherein the processor is configured to determine the sense time period based on an R-R interval of the heart of the patient.

### Claim 38 (depends on 37)

The system of claim 37, wherein the processor determining the sense time period based on an R-R interval of the heart of the patient comprises:
measuring a plurality of R-R intervals for the heart of the patient;
calculating a median R-R interval from the measured R-R intervals; and
setting the sense time period to greater than or equal to a predetermined portion of the median R-R interval.

### Claim 39 (depends on 30)

The system of claim 30, wherein the processor is configured to control the stimulation generator to deliver electrical stimulation to block the atrioventricular node of the heart regardless of the sense time period before controlling the stimulation generator to deliver electrical stimulation based on the sensed time period.

### Claim 40 (depends on 39)

The system of claim 39, wherein the processor is configured to control the stimulation generator to deliver electrical stimulation regardless of the sense time period for a stimulation response time period.

### Claim 41 (depends on 30)

The system of claim 30, wherein the processor is configured to control the stimulation generator to terminate the delivery of electrical stimulation based on one or more stimulation termination criteria, wherein the one or more stimulation termination criteria comprises at least one of expiration of an electrical stimulation delivery time period, an accumulation of blanking time periods exceeding a threshold percentage of the electrical stimulation delivery time period, failure to detect a threshold ventricular rate response within an electrical stimulation response time period, or detection of a ventricular tachyarrhythmia.

### Claim 42 (depends on 30)

The system of claim 30, further comprising electrodes adapted to be positioned in the right atrium of the patient and coupled to the stimulation generator,
wherein the processor is configured to control the stimulation generator to deliver the electrical stimulation in the right atrium via the electrodes.

### Claim 43 (depends on 30)

The system of claim 30, wherein the processor is configured to detect an atrial tachyarrhythmia, and, during the detected atrial tachyarrhythmia, anticipate detection of the ventricular tachyarrhythmia in the heart of the patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count.

### Claim 44

A non-transitory computer-readable storage medium comprising instructions for causing a programmable processor to:
increment a counter upon detection of a ventricular tachyarrhythmia event;
anticipate detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
determine a sense time period; and
in response to anticipating detection of the ventricular tachyarrhythmia, deliver electrical stimulation to block the atrioventricular node of the heart over an electrical stimulation delivery time period, wherein the electrical stimulation is delivered during a stimulation time period established based on the sense time period over which ventricular depolarizations can be sensed during the electrical stimulation delivery time period, the stimulation time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 45

A system comprising:
means for anticipating detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
means for determining a sense time period; and
means for, in response to anticipating detection of the ventricular tachyarrhythmia, delivering electrical stimulation to block the atrioventricular node of the heart over an electrical stimulation delivery time period, wherein the electrical stimulation is delivered based on the sense time period over which ventricular depolarizations can be sensed during the electrical stimulation delivery time period,
the electrical stimulation delivery time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 46

A method comprising:
anticipating a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
determining a sense time period; and
in response to anticipating the ventricular tachyarrhythmia, delivering electrical stimulation to block the atrioventricular node of the heart over an electrical stimulation delivery time period, wherein the electrical stimulation delivery time period is based on the sense time period over which ventricular depolarizations can be sensed during the electrical stimulation delivery time period, the electrical stimulation delivery time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 47 (depends on 46)

The method of claim 46, further comprising detecting an atrial tachyarrhythmia, and wherein anticipating detection of the ventricular tachyarrhythmia in the heart of a patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count comprises anticipating, during the detected atrial tachyarrhythmia, detection of the ventricular tachyarrhythmia in the heart of the patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count.

### Claim 48

A method comprising:
incrementing a counter upon detection of a ventricular tachyarrhythmia event;
anticipating detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count;
measuring an RR interval;
determining, using the RR interval, a sense time period over which ventricular depolarizations need to be sensed in order to detect development of a ventricular tachyarrhythmia;
determining a stimulation time period based on the sense time period;
in response to anticipating detection of the ventricular tachyarrhythmia, delivering electrical stimulation to block the atrioventricular node of the heart over a first time period regardless of the sense time period; and
delivering the electrical stimulation during the stimulation time period over a second time period after the first time period, the stimulation time period being bounded by limits that prevent an accumulation of blanking periods applied to a sensing amplifier that would exceed the sense time period.

### Claim 49 (depends on 48)

The method of claim 48, further comprising detecting an atrial tachyarrhythmia, and wherein anticipating detection of the ventricular tachyarrhythmia in the heart of a patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count comprises anticipating, during the detected atrial tachyarrhythmia, detection of the ventricular tachyarrhythmia in the heart of the patient based on the ventricular tachyarrhythmia not yet being detected but the counter reaching the threshold value of the ventricular tachyarrhythmia event count.

### Claim 50

A system comprising:
a stimulation generator configured to deliver electrical stimulation to a patient; and
a processor configured to increment a counter upon detection of a ventricular tachyarrhythmia event; detect an atrial tachyarrhythmia; during the detected atrial tachyarrhythmia, anticipate detection of a ventricular tachyarrhythmia in a heart of a patient based on a ventricular tachyarrhythmia not yet being detected but the counter reaching a threshold value of a ventricular tachyarrhythmia event count; in response to anticipating detection of the ventricular tachyarrhythmia, control delivery of electrical stimulation to block the atrioventricular node of the heart; and terminate the delivery of electrical stimulation based on one or more stimulation termination criteria.