Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Principles of Anesthesia > Week 3 - Cardiac Rhythm Management Devices > Flashcards

Week 3 - Cardiac Rhythm Management Devices Flashcards

1
Q

What are the intrinsic rates of the:

  • SA node
  • Atrial cells
  • AV node
  • HIS Bundle/Bundle Branch
  • Purkinje Cells
  • Myocardial cells
A
  • SA node: 60-100
  • Atrial cells: 55-60
  • AV node: 45-50
  • HIS Bundle/Bundle Branch: 40-45
  • Purkinje Cells: 35-40
  • Myocardial cells: 30-35
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do pacemakers function?

A

Sense intrinsic cardiac electric potentials then electrical impulses are mechanically transmitted to the heart stimulating (triggering) myocardial contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two types of pacemaker leads?

A

Unipolar (been phased out over last 15 years) – pulse generator functions as the Anode

Bipolar – both cathode and anode are present in the lead itself
*advantage - less susceptible to EMI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are implantable cardioverter-defibrillator (ICD) used to treat?

A

Used to directly treat a cardiac tachydysrhythmia such as V-tach or SVT

-if ICD senses a ventricular rate that exceeds the programmed cut-off rate, a cardioversion/defibrillation is initiated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is overdrive pacing?

A

Device paces rapidly for a number of pulses to attempt pace-termination of tachycardia

  • delivers a burst of pacing stimuli which gain control of the heart, stopping the V-Tach
  • pacemaker then continues controlling the heart at a normal rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does each pacemaker letter mean?

A

I: Pacing – O (none), A (atrium), V (ventricle), D (dual)
II: Sensing – O (none), A (atrium), V (ventricle), D (dual)
III: Response – O (none), I (inhibited), T (triggered), D (dual)

IV: Programmability – O (none), P (programmable), M (multiprogrammable), C (communicating), R (rate modulation)
V: Anti-tachycardia Function – O (none), P (pacing), S (shock), D (dual)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the most common pacemaker modes?

A

AAI

VVI

DDD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the AAI pacemaker mode

A

Atrial only anti-bradycardia pacing – Atrium is sensed as well as paced

Failure of the atrium to produce an intrinsic beat within an appropriate time window (determined by lower rate limit), results in atrial pacing pulse emission

*no reaction if the atrium fires normally
*relies on normal AV conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the VVI pacemaker mode

A

Ventricular only pacing – no atrial sensing or pacing (no atrioventricular synchrony

Any failure of the ventricle to produce an intrinsic beat within a certain rate limit, results in a ventricular pacing pulse

May be used in those with slow rate A-frb to ensure adequate ventricle response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the VAT pacemaker mode

A

A sensed atrial beat triggers ventricular pacing

Patients with complete AV block but normal sinus node function need a pacemaker to ensure a ventricular depolarization follows each spontaneous atrial depolarization

Allows physiologic pacing because the paced ventricular rate will “track” the spontaneous atrial rate – allows for overall increased HR in response to increased metabolic demand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the DDD pacemaker mode

A

Dual chamber pacing and sensing – most common in permanent pacemakers

Every atrial and ventricular event is sensed “Smart Mode”

  • If ventricular response is not seen within a programmed limit, a ventricular pace is initiated
  • If atrial activity is absent within a certain rate, it will be paced and then followed by a ventricular pace if there is no intrinsic response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are pacemaker asynchronous modes?

A

Pacing device emits a pacing pulse regardless of intrinsic cardiac rhythm

No sensing – AOO, VOO, DOO

May be used in heart transplant, emergencies

Can cause R on T – paced activity occurs when the membrane attempts to repolarize before depolarization is complete
*sends heart in to v-fib

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are rate responsive pacemakers?

A

Pacemakers that contain sensors that automatically adjust the pacing rate to meet the patients cardiac output needs

Used in patients with sinus node dysfunctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the different rate response technologies for the following sensors:

  • Activity Sensor
  • Minute Ventilation Sensor
  • QT interval based sensor
  • Contractility sensors
A

Activity Sensor: measures mechanical stress to piezoelectric crystals as a result of motion or acceleration

Minute Ventilation Sensor: measures transthoracic impedance change between pacemaker lead and pulse generator

QT-Interval-Based Sensor: measures evoked QT interval changes as estimate of adrenergic tone

Contractility Sensor: measures peak endocardial acceleration as estimate of contractility and global LV function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When is biventricular pacing used?

A

Developed for treatment of heart failure

Pt’s usually have EF of less than 30%

“Synchronization of heart beat”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where are the pacemaker leads placed in the heart for biventricular pacing?

A

Standard pacemaker lead is positioned in right atrium (tracking of sinus node) – used to optimize AV delay in order to improve ventricular filling

Standard pacemaker lead is placed in right ventricle (capture/pacing of RV)

Specialized pacemaker lead is threaded through the coronary sinus into a lateral cardiac vein so the tip resides within the vein lying over top the LV (capture/pacing of LV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the preop considerations for a patient with a pacemaker?

A

Determine the type of device

  • ID card
  • AICD?
  • Interrogation? (mode, dependency, lower rate limit, response to magnet, battery life)

Rhythm strip ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the recommended minimum Cardiac Rhythm Device data collection for periop assessment of a pacemaker?

A
  • Device type, manufacturer, model
  • Is the device or lead under recall or advisory (??)
  • Date and hospital of implant and date of most recent follow-up
  • Follow-up clinic and physician
  • Minimum anticipated battery longevity
  • Pacing dependency, pacing mode, and rate-modulation sensor
  • Recent activity: atrial and ventricular pacing activity, VT, and VF detection
  • Response to magnet (eg, asynchronous pacing, suspended tachycardia detection)
  • Expected response to magnet removal (eg, resume original settings, other)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you determine if a patient is dependent on their pacemaker?

A

Verbal History:

  • does pt have history of syncope? is this what caused the implantation of the pacer?
  • does pt have history of AV ablation?
  • does pt recall being told that he has 3rd degree heart block?

Interrogation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does failure to capture in a pacemaker mean?

A

The pacemaker generates a pacemaker spike but does not produce a depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does failure to sense in a pacemaker mean?

A

The pacemaker does not recognize normal beats and generates an unnecessary pacemaker spike

22
Q

What does failure to output in a pacemaker mean?

A

The pacemaker does not generate a pacemaker spike when it is needed

23
Q

What preop preparation needs to happen for a pacemaker?

A

If pacemaker function is questioned, it must be interrogated

If the pt has an AICD, this function needs to be disabled
-events have occurred where AICD misinterprets electromagnetic interference as a tachydysrhythmia and a shock is delivered – induces VF

24
Q

What happens when a magnet is placed over an AICD?

A
  • A magnet correctly applied to an AICD often results in suspension of tachyarrythmia therapy
  • For most AICDs there is no way to detect appropriate magnet placement
  • Some AICDs may have no magnet response
  • Some can be permanently disabled by magnet application

*call EP – make sure you ask what specific response to magnet is
*pacemaker function of AICDs is not affected by magnet

25
Q

Should rate-responsive pacemakers be disabled for surgery?

A

Consideration should be given to disabling the rate responsive mode of the pacemaker

  • increase in RR and TV and the use of electrocautery have been reported to increase the paced rate
  • pt movement and the use of vibrating saws has induced tachycardia
26
Q

Does the pacemaker mode need to be altered preoperatively?

A
  • Depends on device dependency and how much suspected electromagnetic interference (EMI) will be of concern.
  • The closer the cautery probe is to the pulse generator the greater the risk of adverse interactions – Head, neck, shoulder and thoracic procedures
  • Some devices have a “sleep-mode” – this may need to be deactivated if surgery is late at night
27
Q

What are the concerns of electromagnetic interference with pacemakers?

A

Monopolar “bovie” electro cautery is of most concern

  • ventricular oversensing which causes pacemaker inhibition
  • sometimes pacemaker response is to pace asynchronously at the programmed lower rate (noise reversion usually at a rate of 58 or so)
  • physical damage to device can result in pacemaker failure
28
Q

When is electromagnetic interference of a pacemaker more likely to occur?

A
  • If surgery is <15 cm (6in) from the device or leads (ex: intrathoracic, shoulder, etc) or above the umbilicus
  • If monopolar cautery rather than bipolar cautery is to be used
  • If long (5 seconds) or frequent (5 seconds between) bursts of cautery to be used
  • If the device has unipolar leads or bipoler leads programmed in unipolar mode or with very high sensitivity
29
Q

When should you consider asynchronous mode to avoid EMI of a pacemaker?

A

Patients who are completely pacer dependent – 3rd degree heart block, AV ablation

Head, neck, shoulder, and thoracic surgery

30
Q

How can you avoid EMI of a pacemaker?

A
  • If cautery is far from pacemaker – usually not a problem
  • Place cautery pad far from pacemaker
  • Ask if surgeon can use bipolar
  • Ask surgeon to use short bursts and let surgeon know if there is pacemaker inhibition
  • Place magnet over pacemaker when there is interference??
31
Q

What do you need to do to the ECG monitoring for a pacemaker?

A

Must include the ability to detect pacer spikes

Must switch to “diagnostic” or “pacemaker” mode

*sometimes spikes will still not appear because the signals are weak – try changing lead placement or lead monitoring

32
Q

What are intra-op monitoring considerations for a pacemaker?

A
  • Must include the ability to ensure the paced activity actually produces mechanical systole – pulse ox, art line waveform
  • If pt has biventricular pacer, consider continuous CO monitoring – pt may need increased HR during periop period to meet increased oxygen demand
  • Minimize effects of EMI
  • Must have back up pacing plan (external pads, transvenous pacing, defibrillator, emergency drugs)
  • Know EP pager number
33
Q

What electrolyte and metabolic disturbances may increase the pacing threshold resulting in failure to pace?

A

Acidosis
Alkalosis
Hyperkalemia
Hypoxemia
Myocardial Ischemia
Severe Hyperglycemia

34
Q

What are the special operative considerations for a pacemaker during Lithotripsy?

A

Cardiac generator must be excluded from the lithotripter field

If the lithotripter triggers their output on the R wave, atrial pacing should be disabled to prevent the lithotripter from inappropriately firing on the atrial pacing artifact

35
Q

What are the considerations for ECT for a pt with a pacemaker?

A

AICDs should be deactivated

Possible requirement of asynchronous mode to avoid oversensing

ASA suggest that a temporary pacing system be available if mode is not asynchronous

36
Q

How should external defibrillation pads be placed on a patient with a pacemaker?

A

Placed so that the route of current is perpendicular to the axis of pacing system

37
Q

What are the post-op considerations for a patient with a pacemaker?

A
  • Consult EP to reactivate AICD or to reprogram pacemaker if the mode had been altered
  • If there were any problems intra-op, EP should interrogate pacer
  • Confirmation of device functionality should be preformed at completion of surgery
38
Q

What is the following pacemaker mode?

A

AAI

39
Q

What is the following pacemaker mode?

A

Atrial Failure to Capture

40
Q

What is the following pacemaker mode?

A

DDD

41
Q

What is the following pacemaker mode?

A

DDD

42
Q

What is the following pacemaker mode?

A

DOO with R on T

43
Q

What is the following pacemaker rhythm?

A

Failure to Capture

44
Q

What is the following pacemaker rhythm?

A

Failure to Capture

45
Q

What is the following pacemaker rhythm?

A

Failure to Output

46
Q

What is the following pacemaker rhythm?

A

Failure to Sense

47
Q

What is the following pacemaker rhythm?

A

Failure to Sense

48
Q

What is the following pacemaker mode?

A

VVI

49
Q

What is the following pacemaker mode?

A

VVI

50
Q

What is the following pacemaker mode?

A

VVI rate 60 A-Fib

51
Q

What is the following pacemaker mode?

A

VVI

Advanced Principles of Anesthesia (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions