Pacemaker Patient Follow-up
Module 8
1
Objectives
• List the steps for performing a pacemaker follow-up
• Locate threshold, sensing and impedance data on a
Quick Look™ screen
• Identify broad trends in Cardiac Compass® and HF
Management Reports
• Identify additional resources or information useful for
performing patient follow-up
2
Pacemaker Patient Follow-up
Routine device follow-up
• Typically 1 per year for chronic single chamber and 2 per
year for chronic dual chamber pacemakers
• These guidelines evolved because the primary purpose of
the follow-up was to evaluate the device
• Increasing sophistication of follow-up tools and the
diagnostics the devices provide, may be changing the
purpose of the follow-up, but have not affected the
guidelines
3
Pacemaker Patient Follow-up Steps
Evaluating the device
– Determine the battery voltage
– Check the lead impedance
– Test capture thresholds
– Test sensing thresholds
– Perform a magnet/non-magnet test (required by Medicare in some
US states)
4
Pacemaker Patient Follow-up
Evaluating the Device
• Battery voltage
– To verify the pacemaker’s ability to operate and estimate the
remaining longevity
• Lead impedance
– To verify that the leads are electrically intact
• Capture thresholds
– To verify an appropriate pacing safety margin
• Sensing thresholds
– To verify an appropriate sensing safety margin
– To observe the underlying rhythm
• Magnet/non-magnet test
– To verify Recommended Replacement Time (RRT) has not been
reached
5
Pacemaker Evolution for the Follow-up Clinic
• Battery voltage
– Estimate of remaining time to
replacement
– Most modern devices provide this
estimate in some fashion
– Most modern devices will also
indicate impending elective or
recommended replacement
• Lead impedance
– Measured with interrogation
– Long-term trends, if available, are
very useful
• Pacing thresholds
– In some devices this test is
automatic and performed
routinely (e.g., daily)
• Sensing thresholds
– In some devices this test is
automatic and performed
routinely (e.g., every intrinsic
event)
• Magnet test
– Formerly only way to determine if
Recommended Replacement
Time (RRT) had been reached
– Less of a need as devices now
routinely report RRT condition
6
Battery Voltage
Estimating Remaining Longevity
• Max voltage in a pacemaker battery is typically 2.8 V
– RRT at 2.5 Volts
– Voltage information is provided on the programmer
– Many devices estimate remaining longevity based on % pacing, lead
impedances, and pacing outputs
– Magnet Test evolved as a way to evaluate if RRT criteria is met via a
simple telephone or in-clinic check
• When a magnet is applied, verify if the pacemaker shows normal magnet
behavior or RRT magnet behavior
• For some pacemakers, a magnet initiates a Threshold Margin Test (TMT)
7
Resource
Pacemaker And ICD Encyclopedia
– All device manufactures share essential device information
– All publish encyclopedias
• Medtronic’s version is available on-line, as a download for both
Palm and Pocket PC
– All include information on leads, devices, model numbers, x-ray
identification, etc.
• Includes Beginning-of-Life (BOL) magnet mode and rates
• RRT magnet mode and rates
• Other RRT indicators (e.g., pulse width “stretching”)
8
Status Check
• Determine the magnet and non-magnet modes, and rates for a
Kappa® 700, Model KDR731.
Click for answer
9
Status Check
• Find the Estimated Longevity
Click for answer
Battery Voltage can be
found by selecting
“Battery and Lead
Measurements” under
the Data icon.
10
Magnet Testing
• If required:
– Use a donut magnet (or the programming head)
– Record the ECG with and without the magnet
• Medicare guidelines call for a 30-second recording of each
– Observe the ECG for asynchronous pacing with the magnet
– Measure the pacing rate
• Some modern devices provide a specific magnet test as an
option on their programmer
11
Lead Impedance
• Can you recall why knowing the lead impedance is
important?
Click for answer
– Because the lead impedance can warn you of a lead insulation
failure or a lead conductor fracture
– At implant, it could indicate a loose set screw
• Can you recall the expected range of lead impedances?
Click for answer
– Normally, 300-1000 Ω, although some specially designed leads may
be higher
12
Status Check
• Find the lead impedances
Click for answer
These trends
show stable
impedances. For
more information,
touch the
chevron.
13
Pacing Thresholds
• Can you recall the pacing output safety margin on a
chronic system?
Click for answer
– Multiply the amplitude threshold by two
• Can you recall the maximum you would want to program
the amplitude, assuming a threshold of < 1.0 V?
Click for answer
– Normally, try to keep the output amplitude at < 2.5 V
– Patient safety is paramount
14
Status Check
• Find the pacing thresholds
Click for answer
These trends
show stable
thresholds. Note
how the atrial
threshold has
decreased since
implant.
For more
information, touch
the
chevron.
15
Threshold Testing
Manual Methods
• The device automatically performs threshold tests
But where would
you find a manual
threshold (or
other) test?
Click for answer
16
Status Check
• Recall the definition of the pacing threshold…
Click for answer
– The minimum output at which the myocardium is consistently
captured, outside of its refractory period.
17
Performing a Manual Pacing Threshold Test
• Process
– Tell the patient what you are going to do
– Force pacing
– Periodically lower the test value (amplitude or pulse width)
– Stop the test once Loss-of-Capture (LOC) is seen on the ECG
– The value just above LOC is the threshold
1.25 V
1.00 V
0.75 V
18
Status Check
• Find the P- and R-wave measurements
Click for answer
To see the P- and
R-wave trends,
touch the
chevron.
19
Sensing Tests
Manual Methods
• This device automatically measures P- and R-waves
But where would
you find a manual
sensing (or other)
test?
Click for answer
20
Status Check
• What is the definition of the sensing threshold?
Click for answer
– The minimum signal size required to inhibit (or trigger) the
pacemaker
21
Performing a Manual Sensing Test
• Process
– Tell the patient what you are going to do
– Reduce (if necessary) the pacing rate to allow the intrinsic
events to occur
– Periodically increase the test value (e.g., for 0.5 mV to 1.0 mV)
– Observe the ECG for loss of inhibition (pacing despite the
presence of P- or R-waves)
– The value, just lower than when pacing occurs, is the size of the
P- or R-wave
22
Routine Testing
• With almost all manufacturers, routine threshold and
sensing tests can be performed on a programmer interface
that guides you through the steps
– Observe the patient carefully for symptoms or complaints
– Follow the on-screen directions and closely observe the ECG for
changes
23
Other Routine Tests
• Underlying rhythm
– Can frequently ascertain the underlying rhythm during the
sensing test
– Optionally, you can perform this test with the programmer
• Retrograde conduction
• Etc.
– Done per clinic protocol, or only if needed
24
So We’ve Checked the Pacemaker
• Is that all there is to it?
• Well…
– Is Rate Response programmed appropriately?
• Can the patient achieve rates to support activities of daily living?
– Is the patient having any arrhythmias?
• What kind of arrhythmias, what rates, what triggers?
– Can we program the device to extend its longevity?
• Can we encourage intrinsic events?
…are just some of the questions we can answer by
looking at the device diagnostics.
25
Optimizing Pacemakers for Patients
• Always evaluate the
rate histograms
– Look for a “staircase” distribution of
rates
– Ask about the
patient’s ability to
achieve their
desired levels of
activity
Rates below the LRL
may occur because of a
timing anomaly.
Rates above the
UTR/USR may indicate
an arrhythmia.
26
Optimizing Pacemakers for Patients
• Always evaluate for the presence of arrhythmia
– What type?
– Is the patient symptomatic?
Cardiac Compass is a simple way to stay
informed of trends in the patient’s atrial
arrhythmia burden.
Cardiac Compass also provides
trends on the ventricular
response to these arrhythmia.
27
Episode Specific Diagnostics
In pacemakers, stored EGMs can be useful:
– Confirming accuracy of other arrhythmia diagnostics
• For example – is oversensing triggering arrhythmia collection?
– Collecting arrhythmia triggers
– An EGM is an ECG recorded via the pacemaker’s leads and stored
in the device
Stored EGM of an episode of AF
28
Optimizing Pacemakers for Patients
• Always evaluate the percent pacing
– Many devices have a percent pacing counter, or look to the
histograms for this information
– Device longevity is affected by pacing outputs
• High outputs decrease longevity
• Low outputs (below about 2.0 V) don’t have as dramatic of
an affect
– So reducing the percentage of unnecessary pacing will
improve device longevity and there may be other benefits to
patients (more later)
29
Reducing the Pacing Percentage
Managing AV delays
• Use auto AV extension algorithms (e.g., Medtronic’s
Search AV+) with Auto-PVARP options to:
– Reduce unnecessary right ventricular pacing
– Allow higher UTR
– Guard against retrograde conduction
30
Reducing the Pacing Percentage
Search AV+ example:
– AV intervals are scanned
– If the majority end in pacing (8/16) the AV delay is automatically
increased
Note: AV scanning algorithms will typically still result in
ventricular pacing about 40-50% of the time.
31
Using Other Diagnostics
• Some devices include indicators of HF status
and can be very useful
• For example: HR variability, Average day/night
rates, Activity trends
• Otherwise be guided by:
• The patient’s diagnosis, complaints, symptoms
32
Clinic Evolution
Taking Advantage of Pacemaker Automaticity
• Devices do not routinely require extensive testing to
confirm they are operating correctly
– But when troubleshooting a particular problem is required, most
devices today offer detailed data that may help assist with analysis
of device, lead and disease progression concerns
• If all tests can be performed automatically, and if we could
view all device diagnostics remotely, why not:
– Use the pacemaker clinic only when a device has a problem or
requires reprogramming
– Allow the physician to determine if routine clinic visits are
warranted?
33
Medtronic CareLink® Network Example
Clinic A
******
Click to Login
34
CareLink™ Network Example
Pick the patient
transmission
Note: the patient information is fictitious
35
CareLink™ Network Example
36
Status Check
Case 1
This patient has had a DDDR pacemaker for 6 years
– Functioning normally
– On a routine telephone check, the following strip is transmitted
– The patient’s magnet is in place
– What conclusions can you draw?
Click for answer
Asynchronous pacing
A-A
interval
705ms
V-V
interval
705ms
Normal magnet behavior, operating in DOO mode at 85 ppm
37
Status Check
Case 2
This patient was implanted about 6 months ago for SND
He came to the clinic
for a wound check 2
weeks post op. This is
first IPG clinic visit.
This (hypothetical)
pacemaker requires
that you do all the
testing.
How is the device
currently programmed?
Click for answer
38
Status Check
Case 2
Results of pacemaker testing:
– Battery voltage: 2.78 V
– Sensing:
• P-waves 2.0-2.5 mV
• R-waves >22.8 mV
• Underlying rhythm Sinus Brady at 50 bpm
– Thresholds
• Atrial 1.0 V tested at 0.4 ms
• Ventricular 0.8 V tested at 0.4 ms
39
Status Check
Case 2
• What programming changes (if any) would you
recommend?
Click for answer
• Re-program the A and V outputs to 2.0 V at 0.4 ms is reasonable.
The leads should be stable at 6 months post implant.
• Would you run any other tests or investigate any further?
Click for answer
– The underlying rhythm indicates intact conduction. Consider
programming a Search AV algorithm to reduce unncessary
ventricular pacing.
– Check the rate histograms and question the patient for the
adequacy of his rate response.
– Check other diagnostics for the presence of arrhythmia.
40
Status Check
Case 3
• This elderly patient had a DDDR implanted for sinus node
dysfunction 8 weeks ago
– Discovered sinus node disease with pauses on routine physical
– Past medical history includes hypertension
• She denies palpitations
• Treatment: Hydrochlorothiazide (blood pressure medication)
– Patient comes to the clinic for her first routine check
– All values within normal and expected limits
– Atrial and Ventricular outputs reduced to a 2.5x safety margin
• No other changes made
41
Status Check
Case 3
Cardiac Compass Report
Is she having
AF?
How much
AF is she
having?
Click for answer
Episodes totaling 8 hours on one day, about 4 hours on two days, and
several shorter episodes 1 min to 1 hour durations thereafter.
42
Status Check
Case 3
Cardiac Compass Report
Is the ventricular
response to AF well
controlled?
Click for answer
Yes, as a very low percent of the ventricular response to AF is > 100 bpm.
43
A Couple of Questions
• In patients with paroxysmal AF (PAF), how likely are they to
experience symptoms of AF?
Click for answer
Asymptomatic PAF occurs 12.1 times as often as symptomatic PAF in
symptomatic patients [Page et al, Circulation 89(1):224-7, 1994]
Asymptomatic PAF occurs in 22-27% of patients with clinical improvement
[
Wolk et al, Int J Cardiol 54:207-211, 1996]
• What is the risk of stroke or CVA to someone with
untreated AF?
Click for answer
5-7% per year. The take-away: AF is silent and dangerous.
44
Status Check
Case 3
• Based on the Cardiac Compass® data, the MD decides to
add Sotalol 160 bid and Coumadin
• The patient returns 6 months later
– Is her arrhythmia status improved?
Click for answer
Yes, it has improved. Her last episode was at the end of May.
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A Couple More Questions
• For this patient, how would you make the diagnosis of PAF
without these kinds of diagnostics?
– She had no symptoms
– She was not in AF on clinic visits
• For this patient, how would you evaluate the effectiveness
of your treatment without these kind of diagnostics?
– Her Medication regimen was not that effective in suppressing her AF
– She had no symptoms
– She was not in AF on clinic visits
46
Brief Statements
Indications
•
Implantable Pulse Generators (IPGs) are indicated for rate adaptive pacing in patients who ay benefit from increased
pacing rates concurrent with increases in activity and increases in activity and/or minute ventilation. Pacemakers are
also indicated for dual chamber and atrial tracking modes in patients who may benefit from maintenance of AV
synchrony. Dual chamber modes are specifically indicated for treatment of conduction disorders that require restoration
of both rate and AV synchrony, which include various degrees of AV block to maintain the atrial contribution to cardiac
output and VVI intolerance (e.g. pacemaker syndrome) in the presence of persistent sinus rhythm.
•
Implantable cardioverter defibrillators (ICDs) are indicated for ventricular antitachycardia pacing and ventricular
defibrillation for automated treatment of life-threatening ventricular arrhythmias.
•
Cardiac Resynchronization Therapy (CRT) ICDs are indicated for ventricular antitachycardia pacing and ventricular
defibrillation for automated treatment of life-threatening ventricular arrhythmias and for the reduction of the symptoms of
moderate to severe heart failure (NYHA Functional Class III or IV) in those patients who remain symptomatic despite
stable, optimal medical therapy and have a left ventricular ejection fraction less than or equal to 35% and a QRS
duration of ≥130 ms.
•
CRT IPGs are indicated for the reduction of the symptoms of moderate to severe heart failure (NYHA Functional Class
III or IV) in those patients who remain symptomatic despite stable, optimal medical therapy, and have a left ventricular
ejection fraction less than or equal to 35% and a QRS duration of ≥130 ms.
Contraindications
•
IPGs and CRT IPGs are contraindicated for dual chamber atrial pacing in patients with chronic refractory atrial
tachyarrhythmias; asynchronous pacing in the presence (or likelihood) of competitive paced and intrinsic rhythms;
unipolar pacing for patients with an implanted cardioverter defibrillator because it may cause unwanted delivery or
inhibition of ICD therapy; and certain IPGs are contraindicated for use with epicardial leads and with abdominal
implantation.
•
ICDs and CRT ICDs are contraindicated in patients whose ventricular tachyarrhythmias may have transient or
reversible causes, patients with incessant VT or VF, and for patients who have a unipolar pacemaker. ICDs are also
contraindicated for patients whose primary disorder is bradyarrhythmia.
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Brief Statements (continued)
Warnings/Precautions
• Changes in a patient’s disease and/or medications may alter the efficacy of the device’s programmed
parameters. Patients should avoid sources of magnetic and electromagnetic radiation to avoid
possible underdetection, inappropriate sensing and/or therapy delivery, tissue damage, induction of an
arrhythmia, device electrical reset or device damage. Do not place transthoracic defibrillation paddles
directly over the device. Additionally, for CRT ICDs and CRT IPGs, certain programming and device
operations may not provide cardiac resynchronization. Also for CRT IPGs, Elective Replacement
Indicator (ERI) results in the device switching to VVI pacing at 65 ppm. In this mode, patients may
experience loss of cardiac resynchronization therapy and / or loss of AV synchrony. For this reason,
the device should be replaced prior to ERI being set.
Potential complications
• Potential complications include, but are not limited to, rejection phenomena, erosion through the skin,
muscle or nerve stimulation, oversensing, failure to detect and/or terminate arrhythmia episodes, and
surgical complications such as hematoma, infection, inflammation, and thrombosis. An additional
complication for ICDs and CRT ICDs is the acceleration of ventricular tachycardia.
• See the device manual for detailed information regarding the implant procedure, indications,
contraindications, warnings, precautions, and potential complications/adverse events. For further
information, please call Medtronic at 1-800-328-2518 and/or consult Medtronic’s website at
www.medtronic.com.
Caution: Federal law (USA) restricts these devices to sale by or on the order of a physician.
48
Brief Statement: Medtronic Leads
Indications
• Medtronic leads are used as part of a cardiac rhythm disease management system. Leads are
intended for pacing and sensing and/or defibrillation. Defibrillation leads have application for patients
for whom implantable cardioverter defibrillation is indicated
Contraindications
• Medtronic leads are contraindicated for the following:
• ventricular use in patients with tricuspid valvular disease or a tricuspid mechanical heart valve.
• patients for whom a single dose of 1.0 mg of dexamethasone sodium phosphate or dexamethasone
acetate may be contraindicated. (includes all leads which contain these steroids)
• Epicardial leads should not be used on patients with a heavily infracted or fibrotic myocardium.
• The SelectSecure Model 3830 Lead is also contraindicated for the following:
• patients for whom a single dose of 40.µg of beclomethasone dipropionate may be contraindicated.
• patients with obstructed or inadequate vasculature for intravenous catheterization.
49
Brief Statement: Medtronic Leads (continued)
Warnings/Precautions
• People with metal implants such as pacemakers, implantable cardioverter defibrillators (ICDs), and
accompanying leads should not receive diathermy treatment. The interaction between the implant and
diathermy can cause tissue damage, fibrillation, or damage to the device components, which could
result in serious injury, loss of therapy, or the need to reprogram or replace the device.
• For the SelectSecure Model 3830 lead, total patient exposure to beclomethasone 17,21-dipropionate
should be considered when implanting multiple leads. No drug interactions with inhaled
beclomethasone 17,21-dipropionate have been described. Drug interactions of beclomethasone
17,21-dipropionate with the Model 3830 lead have not been studied.
Potential Complications
• Potential complications include, but are not limited to, valve damage, fibrillation and other arrhythmias,
thrombosis, thrombotic and air embolism, cardiac perforation, heart wall rupture, cardiac tamponade,
muscle or nerve stimulation, pericardial rub, infection, myocardial irritability, and pneumothorax.
Other potential complications related to the lead may include lead dislodgement, lead conductor
fracture, insulation failure, threshold elevation or exit block.
• See specific device manual for detailed information regarding the implant procedure, indications,
contraindications, warnings, precautions, and potential complications/adverse events. For further
information, please call Medtronic at 1-800-328-2518 and/or consult Medtronic’s website at
www.medtronic.com.
Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.
50
Disclosure
NOTE:
This presentation is provided for general educational purposes
only and should not be considered the exclusive source for this
type of information. At all times, it is the professional
responsibility of the practitioner to exercise independent
clinical judgment in a particular situation.
51