1. Single and Dual Chamber Pacemaker Timing Module 6
Student Notes
This module introduces single and dual chamber pacemaker timing.
The module will also describe the baseline information necessary for working toward more advanced knowledge in pacemaker operation.
It is possible that you may require additional supplemental materials to enhance your knowledge or provide more practice. If you feel this is necessary for you, ask your instructor for suggestions on books or other tools.
Instructor Notes
This module should take approximately 1 hour to cover.
To deliver this module, the following materials are recommended:
Printed participant guides for each participant
Overhead projector and screen
Pacemaker Code and Rate and Interval Conversion Pocket Reference (UC m EN) for each participant
Optional: Whiteboard or flip chart
While delivering the module, engage the learners by asking questions and getting them to talk about the subject based on their previous knowledge.
Evaluate the learners by delivering the knowledge check at the end of the module. An acceptable score is 90%.
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January 2008

2. Objectives Identify VVI, AAI, DDI, and DDD pacing on an ECG strip
Identify basic dual chamber timing concepts
Rate intervals
Inhibition
Triggering
Complete a simple VVI and DDD timing diagram
Demonstrating rate calculation
Demonstrating inhibition
Demonstrating magnet application
Student Notes
Instructor Notes

3. Pacemaker Mode Defines the chambers that are paced/sensed
Defines how the pacemaker will respond to intrinsic events
Defines if rate modulation is available (i.e., DDDR)
Student Notes
To understand pacemaker timing, which is to say - to understand, predict and troubleshoot pacemaker behavior - it is critical that one understand pacemaker modes.
Instructor Notes
The pacemaker mode defines the capabilities and actions of the pacemaker.

4. NBG Code I II III IV V Chamber(s) Paced Chamber(s) Sensed
Response to Sensing
Rate Modulation
Multisite Pacing
O = None
A = Atrium
V = Ventricle
D = Dual (A + V)
S = Single (A or V)
T = Triggered
I = Inhibited
D = Dual (T + I)
R = Rate modulation
Student Notes
Modes are described in a shorthand “code,” which is standard. The first position or letter describes the chamber(s) paced, the second the chamber(s) sensed, the third the response to sensing – probably the most confusing to those new to pacing. The fourth position describes communicating and programming functions, but since all modern devices are multi-programmable, this position has come to signify rate-responsive mode only. We’ll discuss this a bit later. The fifth position is used to describe any anti-tachycardia functions of a device, generally not standard features in a typical pacemaker.
The NASPE/BPERG Generic Pacemaker Code for Antibradyarrhythmia
and Adaptive Rate Pacing and Antitachyarrhythmia Devices
PACE 25: , 2002
Instructor Notes
The NBG pacemaker mode is FUNDAMENTAL to understanding and troubleshooting pacemakers. Examples and exercises will be provided as we discuss single and dual chamber timing in future modules.
Distribute the Pacemaker Code and Rate and Interval Conversion Pocket Reference card to the class.
Draw different heart rhythms (AF, normal sinus rhythm, complete heart block, etc.) on a whiteboard or flipchart. Without getting into timing details, apply different modes to the rhythms. For example:
AF: Use VVI do show how pacing occurs when not inhibitted by a sense
Normal sinus rhythm: Show how pacing is inhibited
Complete heart block: Show how atrial pacing is inhibited, but ventricular pacing is triggered

5. NBG Code – The Usual Pacing ModesII
III IV V
Chamber(s) Paced
Chamber(s) Sensed
Response to Sensing
Rate Modulation
Multisite Pacing
O = None
A = Atrium
V = Ventricle
D = Dual (A + V)
S = Single (A or V)
T = Triggered
I = Inhibited
D = Dual (T + I)
R = Rate modulation
Student Notes
Here are typical pacing modes.
Instructor Notes
Say: To keep from becoming overwhelmed, let’s limit our discussion to those modes found in everyday clinical practice. We will spend most of our time discussing and interpreting ECG strips that demonstrate these operations. Learn these operations, and the less typical modes will be easy.
Ask: What modes have you heard of?
Expected replies: DDD, VVI, VVIR, DDDR
Say: These will be some of the modes of operation that we cover in the coming slides.
With the assistance of the Pacemaker Code and Rate and Interval Conversion Pocket Reference card, ask learners to state functional abilities of DDD, DDDR, DDIR, VVI, VVIR, and AAI.
Examples
DDD
DDDR
DDIR
VVI
VVIR
AAI

6. Rate and Interval Review
Calculated on the horizontal axis
At 25 mm/s speed
Each small box = 40 ms
Each bold box = 200 ms
Student Notes
Before being able to understand pacemaker codes, it is necessary to have an understanding of pacemaker timing. Cardiac devices calculate everything in terms of intervals, from one event to the next.
For example, we’ve seen VVI pacing at a rate of 60 bpm. To the pacemaker this is simply:
1. Pace every 1000 ms.
2. If a sense occurs, then reset the lower-rate timer to zero, and then go to rule 1.
There are some other timing rules in operation, but these are the two fundamental rules for the lower rate in VVI.
Note: When converting from interval to bpm, or vice versa, it is appropriate to use the calculation or the “Rate and Interval Conversion Chart” on the Pacemaker Code and Rate and Interval Conversion Pocket Reference card.
Instructor Notes
Auto animated slide
Point out the “Rate and Interval Conversion Chart” on the Pacemaker Code and Rate and Interval Conversion Pocket Reference card.
Ask: What is a rate of 100 bpm in ms?
600 ms
Ask: What if you measured an interval of 500 ms, what would be the rate in bpm?
120 bpm
How do you convert intervals to rate?
Click for Answer
60,000 / (Interval in ms) = Rate in bpm

7. VVI Mode Chamber paced: Ventricle Chamber sensed: Ventricle
Response to sensing: Inhibited
A ventricular sense:
Inhibits the next scheduled ventricular pace
Student Notes
The VVI mode is very straightforward. The pacemaker paces in the ventricle, senses in the ventricle, and is inhibited (delays pacing) if a ventricular intrinsic beat is sensed.
Instructor Notes
Ask: In what instances would a pace be inhibited in VVI?
When the ventricular rate is faster than the pacing rate

8. VVI Example Chamber paced: Ventricle Chamber sensed: Ventricle
Response to sensing: Inhibition
VVI 60 = Lower Rate timer of 1000 ms
Pacing every 1 second if not inhibited
Lower Rate Timer 1000 ms
Lower Rate Timer 1000 ms
Lower Rate Timer ….
Student Notes
Here is an example of VVI pacing at a rate of 60 bpm. The pacemaker is scheduled to deliver a pacing pulse every 1000 ms. (1000 ms = 1 second = 60 bpm).
The pacemaker will continue to deliver a pacing pulse once every second until:
An intrinsic ventricular beat is sensed
The pacemaker’s mode is reprogrammed or
The battery depletes
Instructor Notes
Auto-animated slide VP VP VP

9. VVI Example VVI 60 Chamber paced: Ventricle Chamber sensed: Ventricle
VVI 60 = Lower Rate timer of 1000 ms
Pacing every 1 second if not inhibited
Chamber sensed: Ventricle
Response to sensing: Inhibition
A ventricular sense interrupts the pacing interval, resets the lower rate timer, and inhibits the next scheduled paced (x) VP VS
Lower rate timer 1000 ms x
Student Notes
If an intrinsic ventricular beat is sensed, the pacemaker (since it is VVI) inhibits. All this means is that the pacemaker stops and then restarts the lower rate timer on that sensed event. The originally scheduled pacing output is inhibited (the X above) and rescheduled.
Instructor Notes
Auto-animated slide

10. VOO Mode VOO 60
The intrinsic ventricular event cannot be sensed, and thus, does not interrupt the pacing interval.
1000 ms VP
Student Notes
In VOO mode, intrinsic ventricular events are not sensed. This results in fixed-rate pacing in the ventricle at the lower rate. This is how the original pacemakers worked – fixed rate or “asynchronous” pacing. Many pacemakers today behave this way when a strong magnet is placed over the pacemaker generator.
Instructor Notes
Auto animated slide
Ask: Based on what you have just learned, how do you think a VOO pacemaker will behave?
Since there is no sensing and no response to sensing – the pacemaker paces at a fixed rate – the lower rate. All intrinsic events are ignored.
One cautionary note – the language of pacing can be confusing. For example, if VOO is asynchronous pacing, don’t be tempted into thinking that VVI is synchronous pacing – IT IS NOT. When we say “synchronous pacing,” we really mean pacing to provide AV synchrony. We’ll discuss this next.
Chamber paced: Ventricle Chamber sensed: None Response to sensing: None
VOO results in fixed-rate pacing in the ventricle. Placing a magnet over the pacemaker usually results in this behavior at known rates, for example, 85 ppm.

11. DDD Mode Chamber paced: Atrium & ventricle
Chamber sensed: Atrium & ventricle
Response to sensing: Triggered & inhibited
An atrial sense:
Inhibits the next scheduled atrial pace
Re-starts the lower rate timer
Triggers an AV interval (called a Sensed AV Interval or SAV)
An atrial pace:
Triggers an AV delay timer (the Paced AV or PAV)
A ventricular sense:
Inhibits the next scheduled ventricular pace
Student Notes
In dual chamber pacing, as the name implies, both the atrium and ventricle are used and affected by the pacemaker. One of the most common dual chamber modes is DDD. In DDD the atrium can be paced and sensed, as can the ventricles.
So the pacemaker must be able to “see” P- and R- waves, but what is the response to sensing?
The final D in DDD indicates a dual response to sensing – we mean the pacemaker can inhibit AND trigger. Let’s look at some examples.
Instructor Notes
Ask for questions before proceeding into Dual Chamber timing.
If learners are unsure of the meaning of VVI pacing, stop now and take a couple of minutes to review.

12. DDD Examples The Four Faces of DDD
Atrial and ventricular pacing
Atrial pace re-starts the lower rate timer and triggers an AV delay timer (PAV)
The PAV expires without being inhibited by a ventricular sense, resulting in a ventricular pace A P V
Student Notes
Example #1
On this slide, we see AV sequential pacing. Both the atrium and the ventricles are being paced, first the atrium and then the ventricle.
Let’s focus on only the 2 complexes shown.
The pacemaker begins by pacing in the atrium. 2 timers are started:
The lower rate timer
The AV Interval timer (we call this timer the PAV or Paced AV interval)
The AV Interval timer expires WITHOUT BEING INHIBITED by a ventricular sense – so the pacemaker paces in the ventricle. The lower rate timer continues. If it expires without being inhibited by an atrial event (as shown above), the pacemaker paces in the atrium, and the cycle begins again.
Instructor Notes
Auto-animated slide
After discussing,
Ask: Why does the pacemaker’s AV interval timer expire without being inhibited?
Perhaps the patient has a heart block
Perhaps the patient has delayed AV conduction — the patient’s P-R interval is longer than the PAV programmed into the pacemaker
Ask: Why does the pacemaker’s atrial escape interval expire?
The patient’s sinus rate is less than the pacemaker’s programmed rate (i.e., sinus bradycardia)

13. DDD Examples The Four Faces of DDD
Atrial pacing and ventricular sensing
Atrial pace restarts the lower rate timer and triggers an AV delay timer (PAV)
Before the PAV can expire, it is inhibited by an intrinsic ventricular event (R-wave) A P V S
Student Notes
Example #2
In this second example we see atrial pacing with an intrinsic ventricular response (VS).
The pacemaker begins by pacing in the atrium. The 2 timers are started:
The lower rate timer
The AV Interval timer (this is again the PAV or Paced AV interval)
The AV Interval timer IS INHIBITED by a ventricular sense – so the AV timer is reset, but the lower rate timer continues. It expires without being inhibited by an atrial event, so the pacemaker paces in the atrium, and the cycle begins again.
In this case the:
Patient’s intrinsic AV conduction occurs faster than the PAV interval, but the patient’s sinus rate (his A-to-A interval) is still longer than the lower rate interval programmed into the pacemaker.
Instructor Notes
Auto animated slide

14. DDD Examples The Four Faces of DDD
Atrial sensing, ventricular pacing
The intrinsic atrial event (P-wave) inhibits the lower rate timer and triggers an AV delay timer (SAV)
The SAV expires without being inhibited by an intrinsic ventricular event, resulting in a ventricular pace A S V P
Student Notes
Example #3
In this third example we see P-waves followed by ventricular pacing. This is also called “tracking,” and is pretty common in pacemakers programmed to the DDD mode.
An intrinsic P-wave inhibits the scheduled atrial output. The lower rate timer is reset to zero and begins again. The AV interval timer (this time called a Sensed AV or SAV – because it follows a sensed atrial event) begins. This timer expires before a ventricular sense occurs, so a ventricular pace occurs, and the lower rate timer continues, and before it can expire, another intrinsic atrial event is sensed and the cycle begins again.
Another way to describe this is that the patient’s A-A interval is shorter than the Lower Rate Interval, but his intrinsic P-R interval is longer than the SAV.
Instructor Notes
Auto-animated slide

15. DDD Examples The Four Faces of DDD
Atrial and ventricular sensing
The intrinsic atrial event (P-wave) inhibits the lower rate timer and triggers an AV delay timer (SAV)
Before the SAV can expire, it is inhibited by an intrinsic ventricular event (R-wave) A S V
Student Notes
Example #4
Finally, we see the pacemaker inhibited by the patient’s intrinsic atrial rate and intrinsic AV conduction. The patient’s A-A interval is shorter than the Lower Rate interval, as his P-R interval is shorter than the programmed AV interval.
Instructor Notes
Auto-animated slide
Ask: Are all four faces of DDD possible for all patients?
No, patients with complete heart block cannot have AS-VS or AP-VS

16. Dual Response to Sensing DDD
The pacemaker can:
Inhibit and trigger
A P-wave inhibits atrial pacing and triggers an SAV interval
An atrial pace triggers a PAV interval
An R-wave inhibits ventricular pacing
We’ll see later how a PVC can affect atrial timing
Student Notes
So we see that the final D in DDD means that the pacemaker potentially has the flexibility to respond to intrinsic events as needed, but the clinician determines the limits of flexibility based on how it is programmed.
Instructor Notes

17. Nuggets Note that in both the single and dual chamber examples:
When the device paces – for the purposes of timing – capture is assumed
Some newer devices have algorithms to check for capture
Sensing is critical to timing
If the device fails to sense, undersensing, it will usually pace
If it “oversenses,” e.g., senses myopotentials, it will inhibit pacing
Student Notes
First, when a device paces, it assumes it has captured the myocardium. It is actually unable to sense the captured event. Although some very modern devices have algorithms to help test and reprogram pacing outputs (like Medtronic’s Capture Management), timing is affected only when the test is being performed.
Another point is that sensing is critical to timing. In most modes, if the device fails to sense (undersensing), it will pace (undersensing -> over pacing). Equally true, in most modes, oversensing -> under pacing.
Instructor Notes
Here is some basic advice about timing, which is useful when you are trying to troubleshoot or understand problems that might be occurring.
More on sensing problems when we discuss troubleshooting.

18. Remember This Strip? Intermittent loss of capture (LOC)
Note how the underlying timing is unaffected by the failure to capture
For timing purposes, pace = capture
Review question: Name some possible causes for this condition.
DDD
Student Notes
Note how the underlying timing is unaffected by failure to capture.
Instructor Notes
Auto-animated slide.
Click for answer.
Use the review question to check on recall of previous modules.
We saw this strip in an earlier module and diagnosed it as intermittent loss of capture, but note how the underlying timing is unaffected. The pacemaker continues to pace at 55 bpm.
Click for Answer
Incomplete fracture, insulation failure, lead dislodgement, poor connection in header, programming error, change in pacing thresholds…

19. Diagnose This Strip
Undersensing, the device fails to reliably “see” P-waves
How do we know this is undersensing?
DDD
Click for Answer
Student Notes
Here is another problem – atrial undersensing. We know this is programmed to DDD. Note how the P-waves are ignored. They do not trigger an SAV nor do they inhibit atrial pacing.
Instructor Notes
Auto-animated slide. Click for answer.
Use the review question to trigger a discussion and check if learners can make the leap.
Because:
The atrial lower rate timer is not inhibited – there are atrial pacing spikes
The intrinsic P-waves do not start an SAV

20. DDI Mode Chamber paced: Atrium & ventricle
Chamber sensed: Atrium & ventricle
Response to sensing: Inhibited
An atrial sense:
Inhibits the next scheduled atrial pace
Re-starts the lower rate timer
An atrial pace:
Starts an AV delay timer (the Paced AV or PAV)
A ventricular sense:
Inhibits the next scheduled ventricular pace
Student Notes
In DDI, the pacemakers response to sensing is to inhibit. It can not trigger. It still paces in the atrium and ventricles, and senses in both chambers, but its only response to sensing is to inhibit.
Instructor Notes
Here is another common dual chamber mode which is often misunderstood.

21. DDI Example
Why would we want a dual chamber pacing mode that does not trigger an SAV?
What rhythm is this? P
Student Notes
What is the clinical utility of such a mode? Today it’s most frequently used when a patient has intermittent atrial arrhythmia.
What does a DDD pacemaker do when faced with intrinsic atrial events? What is its response to sensing?
A DDD pacemaker inhibits atrial pacing and triggers an SAV
What if the atrial events are the result of an atrial tachycardia?
Same answer - A DDD pacemaker inhibits atrial pacing and triggers an SAV
In other words, a DDD pacemaker will attempt to track the atrial tachycardia and provide ventricular pacing up to the programmed limit.
Instructor Notes
Auto-animated slide.
Ask: What does a DDD pacemaker do when presented with atrial events – what is it’s response?
It starts an SAV – an AV interval – and may try to pace the ventricle.
Ask: But suppose the patient had an atrial arrhythmia, would this pacemaker behavior be clinically appropriate? No
Click for Hint
The underlying rhythm is an atrial tachycardia.

22. DDI Example Why would we want to use DDI?
To control pacemaker timing during atrial tachycardias
Avoids a fast paced ventricular response to AT/AF
May limit patient symptoms during AT/AF
Click to change
DDD – tracking the AF
540ms = 110bpm
DDI – Not tracking the AF
Student Notes
A DDD pacemaker in the presence of an atrial tachycardia must track, providing a ventricular response that may not be appropriate for the patient’s metabolic demands, and which may be perceived as palpitations by the patient – resulting in complaints and/or discomfort.
Note how in DDI mode the ventricular rate has slowed to about 90 bpm (est. 660 ms).
Modern pacemakers respond automatically to atrial tachycardias by temporarily reprogramming themselves from DDD to a non-tracking mode like DDI, while the arrhythmia persists. Once it is over they resume their originally programmed mode.
However, the speed and accuracy at which different devices from different manufacturers Mode Switch differs greatly, as does the non-tracking mode. For comparison purposes, modern Medtronic pacemakers (Kappa® 700 and later) Mode Switch in about 3.5 seconds into DDIR.
Instructor Notes
Auto-animated slide
This function has come to be called “Mode Switching”

23. Status Check Calculate the atrial rate Measure the P-R interval
Measure the QRS duration
Student Notes
Instructor Notes
Auto-animated slide
Click for answer
Click for Answer
Atrial Rate: 70 bpm (860 ms)
P-R: 120 ms
QRS: About 100 ms

24. Status Check Which pacemaker modes could be operating on this strip?
Assume normal pacemaker operation
Click for Answer
DDD – Yes, the intrinsic rate could be faster than the lower rate, and the PAV/SAV is longer than the P-R interval.
VVI – Yes, the ventricular rate is faster than the lower rate, thus inhibiting the IPG.
AAI – Yes, the atrial rate is faster than the lower rate, thus inhibiting the IPG.
DOO – No, DOO results in fixed rate pacing. No sensing is possible, no inhibition is possible.
A. DDD
B. VVI
C. AAI
D. DOO
Student Notes
Instructor Notes
Auto animated slide
Click for answer
Choices will fade and correct answers will appear.

25. Status Check Which pacemaker modes could be operating on this strip?
Assume normal pacemaker operation
Click for Answer
DDD – Yes, this is very likely the DDD mode.
VVI – Yes, it could be, but the consistent A-V relationship should make us suspicious.
AAI – No, not possible. Cannot have ventricular pacing in the AAI mode.
DOO – No, DOO results in fixed rate pacing. No sensing is possible, no inhibition is possible. We would see atrial and ventricular pacing if this was DOO.
DDD
VVI
AAI
DOO
Student Notes
Instructor Notes
Auto animated slide
Click for answer
Choices will fade and correct answers will appear.
Discuss each in turn.

26. Status Check Which pacemaker modes could be operating on this strip?
Assume normal pacemaker operation
Click for Answer
DDD – Yes, this is very likely the DDD mode. This is sometimes called “tracking,” as the ventricle is tracking the atrium.
DDI – Not possible. The consistent AV intervals suggest the P-wave is triggering an SAV. DDI inhibits only, triggering not possible.
VOO – Not likely because of the consistent AV intervals. Unable to diagnose until we see the IPG response to an intrinsic ventricular event (evidence of sensing).
DOO – No, DOO results in fixed rate pacing. No sensing is possible, no inhibition is possible. We would see atrial and ventricular pacing if this was DOO.
DDD
DDI
VOO
DOO
Student Notes
Instructor Notes
Auto animated slide
Click for answer
Choices will fade and correct answers will appear.
Discuss each in turn.

27. 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.

28. 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 and/or consult Medtronic’s website at
Caution: Federal law (USA) restricts these devices to sale by or on the order of a physician.

29. 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.

30. 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 and/or consult Medtronic’s website at
Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.

31. 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.
Student Notes
Instructor Notes