# US 9,750,941 B2 · Criteria for determination of local tissue latency near pacing lead electrodes

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- Number: US 9,750,941 B2
- Document ID: US9750941B2
- Status: Granted
- Kind: B2
- Application number: 15/004,487
- Filed: 2016-01-22
- Published: 2016-07-28
- Granted: 2017-09-05
- Earliest claimed: 2015-01-23
- Assignees: Medtronic, Inc.
- Applicants: Medtronic, Inc.
- Inventors: Subham Ghosh
- Web page: https://patentgrep.com/patent/US9750941B2

## CPC

- A61B 5/282: Holders for multiple electrodes (for introduction into the body A61B5/287)
- A61B 5/349: Detecting specific parameters of the electrocardiograph cycle
- A61B 5/363: Detecting tachycardia or bradycardia
- 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)}
- A61N 1/3682: {with a variable atrioventricular delay}
- A61N 1/36842: {Multi-site stimulation in the same chamber}
- A61N 1/36843: {Bi-ventricular stimulation}
- A61N 1/3684: {for stimulating the heart at multiple sites of the ventricle or the atrium}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- 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

A system and method for identifying whether local tissue latency is present. The system and method comprises an implanted lead having a first electrode for cardiac pacing and sensing. A sensing module for sensing heart activity with the first electrode to produce an electrogram (EGM) waveform. A processor is configured to receive the EGM waveform and extract two or more features from the EGM waveform representative of heart activity in response to monoventricular or biventricular pacing stimulus at the electrode and identify local tissue latency at a site of the first electrode based upon at least two of the extracted features indicating local tissue latency.

## Claims

### Claim 1

An apparatus for adjusting one or more control pacing parameters for cardiac pacing, comprising:
(a) delivering means for delivering a left ventricular pacing stimulus at a short atrioventricular (AV) delay equal to or less than 60 ms;
(b) sensing means for sensing a signal in response to the ventricular pacing stimulus;
(c) processing means for determining from the signal a minimum time (Tmin) associated with a minimum amplitude;
(d) processing means for determining whether Tmin≧100 milliseconds (ms); and
(e) processing means for determining whether to adjust one or more control pacing parameters, in response to determining whether Tmin≧100 ms, wherein the control pacing parameters being one of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output.

### Claim 2 (depends on 1)

The apparatus of claim 1, further comprising:
processing means for determining local tissue latency exists in response to determining that the Tmin≧100 ms.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the AV delay is shortened in response to determining that the Tmin≧100 ms.

### Claim 4 (depends on 2)

The apparatus of claim 2, wherein the AV delay is shortened to be less than or equal to 80 ms.

### Claim 5 (depends on 2)

The apparatus of claim 2, wherein the AV delay is shortened to be less than or equal to 60 ms.

### Claim 6 (depends on 2)

The apparatus of claim 2, wherein the AV delay is adjusted by a pre-specified level.

### Claim 7 (depends on 6)

The apparatus of claim 6, wherein the AV delay decreased by a prespecified level being one of 5 ms, 10 ms, 15 ms, 20 ms, 25 ms, 30 ms, 35 ms, and 50 ms.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein acquiring the signal comprises selecting a sensing vector comprising a left ventricular electrode and a right ventricular coil electrode.

### Claim 9 (depends on 1)

The apparatus of claim 1, further comprising:
delivering means for delivering a biventricular pacing at the short AV delay.

### Claim 10 (depends on 1)

The apparatus of claim 1, further comprising:
processing means for adjusting the VV delay so that the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus by about 5 ins or more.

### Claim 12

An apparatus for adjusting one or more control pacing parameters for cardiac resynchronization, comprising:
(a) delivering means for delivering biventricular pacing stimulus comprising a right ventricular pacing stimulus and a left ventricular pacing stimulus simultaneously at a short atrioventricular (AV) delay equal to or less than 60 ms;
(b) sensing means for sensing a signal in response to the biventricular pacing stimulus;
(c) processing means for determining from the signal a maximum amplitude (Max), a maximum time (Tmax) associated with the Max, a minimum amplitude (Min), and a minimum time (Tmin) associated with the Min, determined within pre-specified time period following the delivery of the biventricular pacing;
(d) processing means for determining whether Tmin>Tmax associated with the signal; and
(e) processing means for determining whether to adjust VV delay in response to determining Tmin>Tmax.

### Claim 13 (depends on 12)

The apparatus of claim 12, comprising:
processing means for determining local tissue latency exists in response to determining that Tmin>Tmax.

### Claim 14 (depends on 12)

The apparatus of claim 12, further comprising:
processing means for adjusting the VV delay so that the LV stimulus is delivered 10 ms ahead of the RV stimulus.

### Claim 15 (depends on 12)

The apparatus of claim 12, further comprising:
processing means for adjusting the VV delay so that the stimulus is delivered 20 ms ahead of the RV stimulus.

### Claim 16 (depends on 12)

The apparatus of claim 12, further comprising:
processing means for adjusting the VV delay so that the LV stimulus is delivered 40 ms ahead of the RV stimulus.

### Claim 17 (depends on 12)

The apparatus of claim 12, wherein acquiring the signal comprises selecting a sensing vector comprising a left ventricular electrode and a right ventricular coil electrode.

### Claim 18

A medical device system or determining presence of local tissue latency, the system comprising:
an implanted lead having a first electrode for cardiac pacing and sensing;
a sensing module for producing a waveform in response to delivering a pacing stimulus;
a processor configured to:
(a) setting one or more pacing control parameters including setting an atrioventricular (AV) delay to less than or equal to 60 ms,
(b) extracting two or more features from the waveform, wherein the two or more features comprise at least a minimum time (Tmin) associated with a minimum amplitude of the waveform,
(c) identifying whether local tissue latency is at a site of the first electrode based upon the at least two of the extracted features indicating local tissue latency, and
(d) in response to identifying local tissue latency, adjusting the one or more pacing control parameters.

### Claim 19

An apparatus for adjusting pacing parameters for cardiac resynchronization, comprising
a) delivering a left ventricular pacing stimulus at a short AV delay equal to or less than 60 ms;
b) sensing a signal in response to the left ventricular stimulus and determining if the time-interval between the timing (Tmin) of the minimum amplitude and the time of delivery of the stimulus is 100 ms or greater, where the minimum amplitude is determined within a pre-specified time-period following the delivery of the pacing stimulus;
c) delivering a right ventricular pacing stimulus and a left ventricular pacing stimulus simultaneously at a short AV delay equal to or less than 60 ms;
d) sensing a signal in response to the biventricular pacing stimulus and determining if timing (Tmax) of max amplitude precedes timing (Tmin) of the minimum amplitude where both maximum and minimum amplitudes are determined within a pre-specified time-period following delivery of the pacing stimuli; and
e) adjusting pacing parameters in response to determining if Train for the left ventricular stimulus is 100 ms or greater than 100 ms, or if Tmax precedes Tmin for the biventricular pacing stimulus.

### Claim 20

A non-transitory, computer-readable storage medium comprising instructions that, when executed, cause a processor included in a medical device system to:
(a) deliver a left ventricular pacing stimulus at a short atrioventricular (AV) delay equal to or less than 60 ms;
(b) sense a signal in response to the ventricular pacing stimulus;
(c) determine from the signal a minimum time (Tmin) associated with the minimum amplitude;
(d) determine whether Tmin≧100 milliseconds (ms); and
(e) determine whether to adjust control pacing parameters, in response to determining whether Tmin≧100 ms, wherein the control pacing parameters being one of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output.

### Claim 21

A medical device system for determining presence of local tissue latency, the system comprising:
an implanted lead having a first electrode for cardiac pacing and sensing;
a sensing module for sensing heart activity with the first electrode to produce a electrogram (EGM) waveform; and
a processor configured to:
acquire or access the EGM waveform and extract two or more features from the EGM waveform representative of heart activity at the electrode, wherein the two or more features comprise at least a minimum time (Tmin) associated with a minimum amplitude of the EGM waveform, and
identify local tissue latency at a site of the first electrode based upon the at least two of the extracted features indicating local tissue latency.

### Claim 22 (depends on 21)

The system of claim 21, wherein the processor is further configured to determine whether Tmin≧100 milliseconds.

### Claim 23 (depends on 21)

The system of claim 21, wherein the processor further configured to adjust a pacing control parameter in response to determining Tmin≧100 milliseconds.

### Claim 24 (depends on 21)

The system of claim 21, wherein the processor further configured to deliver pacing at a short atrioventricular (AV) delay equal to or less than 60 ms.

### Claim 25 (depends on 21)

The system of claim 21, wherein the two or more features from the EGM waveform further comprise maximum amplitude, maximum time (Tmax) associated with the maximum amplitude, the processor further configured to determine whether Tmin>Tmax.

### Claim 26 (depends on 25)

The system of claim 25, wherein the processor further configured to adjust a pacing control parameter in response to determining Tmin>Tmax, wherein the pacing control parameter being one of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output.

### Claim 27 (depends on 26)

The system of claim 26, further comprising:
processing means for determining local tissue latency exists in response to determining that the Tmin≧100 ms.

### Claim 28 (depends on 26)

The system of claim 26, wherein the AV delay is shortened in response to determining that the Tmin≧100 ms.

### Claim 29 (depends on 28)

The system of claim 28, wherein the AV delay is shortened to be less than or equal to 80 ms.

### Claim 30 (depends on 28)

The system of claim 28, wherein the AV delay is shortened to be less than or equal to 60 ms.

### Claim 31 (depends on 28)

The system of claim 28, wherein the AV delay is adjusted by a pre-specified level.

### Claim 32 (depends on 31)

The system of claim 31, wherein the AV delay decreased by a prespecified level being one of 5 ms, 10 ms, 15 ms, 20 ms, 25 ms, 30 ms, 35 ms, and 50 ms.

### Claim 33 (depends on 26)

The system of claim 26, further comprising:
delivering means for delivering a biventricular pacing at the short AV delay.

### Claim 34 (depends on 26)

The system of claim 26, further comprising:
in response to identifying local latency tissue, processing means for adjusting the VV delay so that the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus.

### Claim 35 (depends on 34)

The system of claim 34, wherein the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus by about 5 ms or more.