Noise, Reset, EGM, Magnet, Advanced Hysteresis Noise Göran Mathson, 2005.

Noise, Reset, EGM, Magnet, Advanced Hysteresis

Noise

Göran Mathson, 2005

for internal use only

Noise

• Electromagnetic Interference (EMI) or Noise

• At least 400 cycles per minute

• Is very unlikely to be caused by myopotentials


Noise

• EMI in Relative Refractory Period of (RRP) initiates

a Noise Sampling Window (NSW)

• NSW is extension of the RRP

• Noise detected in the Ventricular Channel during

DDD / DDI mode operation extends A and V

refractory period


Noise

• If the Noise persists there will be asynchroneous

pacing at the Base Rate (or Sensor Indicated Rate if

the Sensor is On)

• Pacemaker resumes normal operation at the

programmed parameters as soon as the Noise stops


Noise Mode, Atrial Channel

PVARP

Programmable PVARP

Absolute RelativeA-A Interval


100 ms 175 ms

RelativeAbsolute

Sensed Event

NSW 150 ms

Sensed Event

NSW 150 ms

Noise sampling window (NSW)

Sensed Event

NSW 150 ms

Sensed Event Sensed

Event


Noise Mode, Atrial Channel

A-A Interval

Reset



Reset

When the device has reverted to backup VVI operation, the programmer will display a pop-up message indicating that the device is in back up VVI values.

Under most conditions the previously programmed settings can be restored, by following the on-screen instructions.


Reset parameters

Stored Electrograms



Stored Electrograms

Programmability

Triggers


Stored Electrograms

Stored electrograms are available in the following devices*:

• Zephyr®

• Victory®

• Identity®

• Integrity®

Stored Electrograms

Programmability


Programmability

The device can store a variety of intracardiac configurations for various time frames

The following screen shot demonstrates this programmability


Programmability


Programmability

Sampling Option• This parameter determines how the device treats

additional Stored EGMs after the allocated memory has been filled

• Freeze (nominal) • Once the device has stored the programmed number of

EGMs no more EGMs will be stored

• Continuous• Allows a new Stored EGM to overwrite the oldest

Stored EGM

• First in, First out


Programmability

Number of Stored EGMs

• Determines how many EGMs the device can store

• 1, 2, 4, 8, 12

Maximum Duration

• Calculated by the device based on programmed values


Programmability

Channel

• Determines what IEGMs will be recorded by the device

• Programmed Options• Atrial• Ventricular• Dual• Cross-Channel (nominal)


Programmability

Channel

• Atrial• When selected, this value will cause an Atrial

IEGM to be stored

• Ventricular• When selected, this value will cause a

Ventricular IEGM to be stored


Programmability

Channel

• Dual• Both an Atrial and Ventricular IEGM will be

stored

• Cross-Channel• Both the Atrial and Ventricular IEGM will be

stored on a single electrogram• In some patients, this may resemble a surface

ECG


Programmability


Programmability

Atrial EGM Configuration

• Determines the IEGM to be recorded for the Atrial channel on the Stored EGMs

• The various configurations can be viewed on the real-time EGM


Programmability

Atrial Dynamic Range

• Sets the Stored EGM gain for the Atrial channel

• Programmable Options• 15.0, 7.5, 3.0, 1.5 mV (nominal 3.0 mV)

• These parameters can be previewed on the real-time electrogram


Programmability

Ventricular EGM Configuration

• Determines the IEGM to be recorded for the Ventricular channel on the Stored EGMs

• The various configurations can be viewed on the real-time EGM


Programmability

Ventricular Dynamic Range

• Programmable Options• 15.0, 7.5, 3.0, 1.5 mV (nominal 15.0 mV)

• These parameters can be previewed on the real-time electrogram


Programmability

If AutoCapture™ Pacing Systems is enabled then the Ventricular Configuration is fixed to Vtip-Vring

Stored EGMs

Stored Electrogram Triggers



The device can be programmed to automatically store an EGM when triggered by*:

• Advanced Hysteresis• AT/AF Detection• High Atrial Rate• High Ventricular Rate• AMS Entry• AMS Exit• PVCs• PMT Termination• Patient Activated / Magnet application* Available triggers depend on the pacemaker model. See device manual.


Programmability



Trigger Options

• Advanced Hysteresis• Triggered when Advanced Hysteresis is

activated

• AT/AF Detection• Triggered when AT/AF Detection meets

programmed criteria

• High Atrial Rate• Off, 175, 200, 225, 250, 275, 300

› No, of Consecutive Cycles- 2, 3, 4, 5, 10, 15, 20


Stored Electrogram TriggersTrigger Options

• High Ventricular Rate• Off, 175, 200, 225, 250, 275, 300

› No, of Consecutive Cycles- 2, 3, 4, 5, 10, 15, 20

• AMS Entry• Triggered when the device enters mode

switches

• AMS Exit• Triggered when the device exits mode

switches



Trigger Options

• PVCs• No. of Consecutive PVCs

› 2, 3, 4, 5

• PMT Termination

• Patient Activated • Magnet Placement (magnet applied for at least 1 sec)



Additional Considerations• Pre-trigger data is collected, approximately 50%

of the EGM• Some triggers require an associated feature to be

active• Advanced Hysteresis, AMS Entry, AMS Exit and

PMT Termination

• EGM Storage for High Atrial Rate and AMS Entry and Exit are mutually exclusive

• Can’t be programmed on together



Stored EGMs are disabled:

• When Telemetry is active

• When Elective Replacement Indicator (ERI), has been achieved


Impact of SEGM on Victory

Victory DR - 5816

frozen rolling

No egm 25% egm 50% egm 100% egm

2.5 V atrium and ventricle, 100% inhibited 17.8 14.1 11.6 8.6

2.5 V atrium, 1.0 V ventricle, 100 % pacing 13 10.9 9.3 7.3

2.5 V atrium and ventricle, 100% pacing 11.7 10 8.6 6.8

SR - 5610

frozen rolling

No egm 25% egm 50% egm 100% egm

11.4 8.8 7.2 5.2

10.1 8 6.7 4.9

8.8 7.2 6.1 4.6


Conclusions & RecommendationField -> Customer Education

SEGM in latest SJM pacemakers always records pre-onset the trigger.This may have a significant effect on PG longevity

Use SEGM selectively (for example, if episodes are in the log, patient is symptomatic). Consider using Frozen, not continuous, since it is likely to collect SEGM, then turn off, minimizing current drain.

Magnet Response



•Settings: Off; Battery Test (Nominal: Battery Test)

• How will the PM respond to the magnet placement• Telemetry is disabled when magnet is held over device.• Temporarily suspended functions during magnet is held over

• or Cancelled

The Magnet Response


Terminologie:BOL = Beginning of life

EOL = End of life

ERT = Elective replacement time

ERI = Elective replacement indicator: indication ERT is reached

TMT = Threshold margin test: automatic action

PM Response: VOO DOO AOO Modus Freq. = indication of batt. Condition

Use: Freq. = indication of batt. Condition Troubleshooting – deactivation of algorithms Inhibition of sensing

The Magnet Response


Pacemaker reference guide


Pacemaker reference guide

WWW.SJM.COM

Devices

For Physicians & Health Care Professionals

Implantable Device Reference Guide

http://www.sjm.com/

http://www.sjm.com/devices/devicereferenceguide.aspx

Neurocardiogenic Syncope




Common faint also called “Neurally mediated syncope” or “Vasovagal syncope”

Young adult, structurally normal heart

Malignant vasovagal syncope pacing

• First line therapy: medication

• Ineffective and bradycardic component

3 types: Cardioinhibitory, vasodepression and mixed



3 Major Objectives

• Provide high rate pacing only during the spells

• Otherwise inhibit the pacemaker

• Maintain AV Synchrony


Auto Rate Hysteresis With Search

Most patients with Neurocardiogenic Syncope are in sinus rhythm with intact conduction the majority of the time.

However, if they have an abrupt drop in rate, they may benefit from an elevated rate of pacing.


Programmable parameters

• Hysteresis Rate • Programmable Search Interval• Programmable Cycle Count• Intervention Rate• Intervention Duration• Recovery Time

Advanced Hysteresis Response



Hysteresis Rate

Allows intrinsic activity to be tracked

below the base rate

Programmable Values: OFF, 30 - 130 in 5 min-1, 140, 150



Search Interval

Allows the device to periodically extend the pacing interval to search for intrinsic activity

Programmable Values: OFF, 5, 10, 15, or 30 min.


Cycle Count

The number of intervals the device will extend the pacing interval to search for intrinsic activity.The Cycle Count also serves as the number of cycles thepatient’s intrinsic rate will be allowed to drop below thehysteresis rate before pacing at the Intervention Ratebegins.

Programmable Values: 1-16 cycles




The rate the pacemaker will operate at if the patients intrinsic rate falls below the Hysteresis Rate for the programmed Cycle Count. It is programmable as a fixed value or as a function of the Intrinsic rate.**

Programmable Values: OFF,

Base Rate, 80 - 120 (steps of 10 min-1), Intrinsic + 0, + 10, +20, +30 min-1

** The Intrinsic rate is calculated as the average Ventricular Rate over the previous 64 cycles

Intervention Rate



The time in minutes that the pacemaker will operate at the

Intervention Rate.

Following the Intervention Duration the rate will be

decreased, according to the programmed Recovery Time,

until either the Base Rate or Sensor Indicated Rate is

reached.

Programmable Parameters: 1-10 min (steps of 1 min)

Intervention Duration



Programmable Values• Fast • Medium • Slow • Very Slow

The length of time (in min) that it will take for the pacemaker to reduce the pacing rate from the Intervention Rate to the Base Rate

NOTE: This parameter also servesas the setting for thesensor Recovery Time

Recovery Time


Parameter settings forNeurocardiogenic syncope

Parameter Value Rationale

Pacing mode DDD

DDI

Excer. AV block

Rate modulation DISABLE Even no mild levels

Base Rate 60 -100 bpm Sympt. dependent

Intervention rate

10 – 20 bpm

Above av. rate

Av.= intrins.rate before drop

Hysteresis rate ≤ 45 bpm Asist. >3 sec = 20bpm



Parameters Value Rationale

Rest Rate 45 – 50 bpm Lower rate at rest

Escape Cycles 2 Persistent slow

Cycle Number 3 Sinus warm up

Intervention Duration

2 to 5 minutes The spells are very brief

Recovery Time Medium Same as sensor

AV delay Sufficient / VIP VP not needed

Autocapture Enable Threshold rise



OFF

Noise, Reset, EGM, Magnet, Advanced Hysteresis Noise Göran Mathson, 2005.

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