Brainscape's Knowledge GenomeTM

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


See full index

Pacemakers > Pacemakers > Flashcards

Pacemakers Flashcards

1
Q

Indications for temporary pacemakers

A
  • Symptomatic bradycardia unresponsive to medical therapy
    – 2nd Degree Type II and 3rd Degree Heart Block
    – Permanent pacemaker failure
    – Support cardiac output after cardiac surgery
    – Tachy dysrhythmias (overdrive pacing)
    – Diagnostic studies: Electrophysiology studies (EPS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Permanent pacemaker indications

A

– Sick Sinus Node Syndrome
– Symptomatic AV block
– Pan-conduction disease (often age related conduction tissue changes)
– Hereditary, idiopathic, or drug-related QT interval prolongation

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

Permanent ventricular lead placement

A

 The ventricular lead is usually placed in the apex of the right ventricle and held in
with tines at the end to lead.

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

Permanent Atrial Lead Placement

A

The atrial lead is harder to keep in place due to the smooth surface, therefore often a lead is used with a screw on the end to fix it within the atria
 Some leads emit steroids to reduce inflammation and scarring

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

Pacemaker function: Pace

A

Electrical stimulus to the ventricle or atria
– Capture is the effective depolarization of the heart by the artificial pacemaker
– Capture threshold is the minimum pacemaker output setting required to pace the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pacemaker function: Sense

A

The pacemaker wire senses electrical activity in the chamber in which it is placed

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

Pacemaker function: Pacing triggered

A

The pacemaker fires an electrical stimulus if it senses no electrical activity

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

Pacemaker function: Pacing inhibited

A

The pacemaker inhibits electrical stimulus due to sensed intrinsic rhythm

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

Pacemakers deliver a pacing stimulus only when…?

A

The hearts intrinsic pacemaker fails to function

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

VVI

A
  • The ventricular lead paces the ventricle and inhibits itself if it senses an intrinsic rhythm
  • The patient loses atrial filling and atrial kick (loss of CO)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

DDD

A

– 1st D = both chambers are paced
– 2nd D = both chambers are sensed
– 3rd D = inhibits both atrial and ventricular pacing when sensing intrinsic rhythm; and triggers response to sensed atrial activity to allow for rate responsive pacing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

DDD: Atrial sensed with ventricular paced rhythm

A

– The SA node is intact and pacing normally

– AV synchrony remains intact

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

DDD: Atrial Paced with intrinsic ventricular rhythm

A
  • This strip shows loss of intrinsic SA node activity, the atrial lead then paces the atria
  • The impulse travels normally through the AV node
  • There is intrinsic BBB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Limitations for DDD pacing

A

Atrial pacing cannot be achieved with chronic atrial fib

If a patient with a DDD pacer goes into Afib there are rate limitations set for the atrial and ventricular responses

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

Pacemaker Codes

A
  1. Chamber Paced
  2. Chamber Sensed
  3. Response to Sensing
  4. Rate ResponsiveP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Common occurrence: Fusion Beats

A

 Causes
– A paced and an intrinsic ventricular beat occur simultaneously
– Resulting QRS a mix between intrinsic and paced
Intervention : none

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

Common occurrences: PVC

A

 Causes
– electrode causing irritable ventricular focus
– Note: PVC’s normally occur in the first 24h after lead placement
 Intervention
– May need to administer antiarrhythmic drugs – May need reposition of lead wire

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

Complication: Battery Failure

A

Applying a magnet over the pacer will illicit fixed (asynchronous) pacing
If the battery is failing, the pacer will pace at a different rate than what’s programmed
If the battery of a DDD pacer begins to fail it will convert to VVI to conserve battery time

19
Q

Complication: Loss of output

A

 Possible Causes – Battery depletion – Pacemakeroff
– Oversensing
– Faulty cable connection
– Dislodged/fracturedlead

20
Q

Complication: Failure to capture

A

 The pacemaker spikes fail to initiate the depolarization of the ventricle
– EKG pacemaker spikes not followed by QRS complexes

21
Q

S/S Failure to capture

A

 Signs and Symptoms – bradycardia
– hypotension
– fatigue

22
Q

Failure to capture: Potential causes

A 
– Displacement of the pacing
lead wire (most common)
– mA set too low
– fracture of the lead
– battery failure
– perforation of the myocardium by the lead wire
– edema or scar tissue formation at electrode tip
– fibrin formation at the lead tip
23
Q

Failure to capture interventions

A

 Intervention:
– Notify physician immediately
– The physician may need to reprogram the pacer, replace or reposition the pacing wire
– May reposition patient onto left side

24
Q

Less Common Causes of Noncapture May Include:

A

Twiddler’s syndrome Electrolyte abnormalities – e.g.,

hyperkalemia Myocardial infarction Drug therapy Battery depletion Exit block

25
Q

Accurate Sensing

A

The pacer needs to be able to “see”
If the pacer can’t see the patient’s intrinsic it will fire indiscriminately
 DANGER: R ON T Phenomenon
Rare in today’s sophisticated pacers

26
Q

Complication: Failure to sense

A

 Pacemaker cannot see the patient’s intrinsic rhythm
– EKG pacemaker spikes that fall where they shouldn’t; spikes
may fall on T waves

27
Q

Failure to sense potential causes:

A

– misplacement of ventricular lead placement (most common) – inflammation or swelling around the electrode
– battery failure
– fracture of pacing lead wire

28
Q

Interventions for under-sensing

A

 Interventions: Notify physician
– Reposition the patient to the left side
– The physician may need to reprogram the generator or replace or reposition lead wire
– Prepare for code situation

29
Q

Complications: Oversensing

A

 Lack of pacemaker activity
– pacemaker does not pace or paces at a rate slower than the set rate
 Symptoms depend on underlying rhythm and rate

30
Q

Probably causes of oversensing

A

– the pacemaker may sense or be inhibited by skeletal muscle contractions (more frequent with a unipolar lead)
– electromagnetic interference
– sensing of T waves or atrial activity
– pacemaker sensitivity set too high

31
Q

Complication: Diaphragm pacing

A 
Signs and Symptoms 
– hiccups
– EKG artifact
Possible causes
– stimulation of phrenic nerve by the electrode tip 
– myocardial perforation by lead wire
– excessive pacemaker voltage
 Interventions
– position patient on left side
– surgery (reposition lead wire) – reduce mA
32
Q

Complications: : Chest or Abd. Muscle Stimulation

A 
Signs and Symptoms
– muscle twitching
– pacemaker identification letters appear backward on chest x-ray
Possible causes
– high pacemaker output
– lead fracture or insulation break – flipped pulse generator
 Intervention
– reduce pacemaker output – replace lead
– reposition generator
33
Q

Founded Sources of EMI (Electrical magnetic interference)

A
  1. Use of arc welding machinery
  2. High-tension electrical wires
  3. Carrying cellular phone in pocket near pacemaker generator
  4. Magnetic resonance imaging (MRI)
  5. Radiation therapy to the chest (pacemaker generator should be shielded)
  6. Electrical cardioversion
  7. Electrocautery use during surgical procedures (biggest
    problem in the hospital in regards to EMI)
  8. Lithotripsy treatment
  9. Transthoracic defibrillation 10. TENS Units
34
Q

Pacemaker Syndrome

A

Defined as:
 Loss of AV synchrony
 Retrograde ventriculoatrial (VA)
conduction
 Absence of rate response to physiological need
S & S related to lower cardiac output.
Treatment focuses on use of dual-chamber pacing as well as reprogramming timing.

35
Q

Transcutaneous Pacemaker

A

External pacemakers are built into portable cardiac monitor/defibrillators
The impulse is conducted across the intact chest wall to activate the myocardium
Used for emergent situations

36
Q

Energy and current for transcutaneous pacemaker

A

 The mean current required for electrical capture is usually 50 - 100 mA
 IV analgesia and sedation is required for currents of 50 mA or more

37
Q

Transcutaneous pacing technique

A

 Place the pads on the patient
 Set desired heart rate
 Slowly increase mA until capture is obtained
– Electrical capture is characterized by a pacer spike followed by a QRS
– The QRS will change morphology
– Cardiac capture is assessed by pulse
– Assess hemodynamic response (BP, UO, skin)

38
Q

Transcutaneous pacing precautions

A

 Precautions
– Failure to capture may occur due to electrode placement or
patient size and body habitus (barrel-shaped chest)
– Transcutaneous pacing contracts the chest muscle therefore:
The rhythm strip could look like capture is occurring but just the chest wall is contracting
– must check pulse for cardiac capture
Failure to recognize the presence of treatable VF Failure to recognize that pacemaker is not capturing
– Third degree burns can occur with prolonged use

39
Q

Antitachycardia overdrive pacing

A

– accomplished by pacing the heart for a few seconds at a rate faster than the tachycardia rate, then returning to the regularly paced or intrinsic rhythm
– This is usually incorporated in implantable defibrillator devices

40
Q

Three lead pacing for BBB and CHF

A

– Pacing the atria and both ventricles to improve CO (cardiac resynchronization or CRT)

41
Q

Pacemaker mediated tachycardia

A

Can be stopped by placing a magnet over the generator

If SVT is in progress, the magnet will have little effect

42
Q

Pacemaker and magnet application

A

Magnet will result in asynchronous (DOO or VOO) pacing at either 65 or 85 BPM (for a Medtronic device) depending on battery status
Application will not permanently affect the device (most devices)

43
Q

Analyzing pacemaker function

A

Identify the intrinsic rate and rhythm – are P waves present - what rate
– are QRS complexes present - what rate
Note evidence of paced activity: atrial, ventricular, both
– measure the distance between two consecutive paced beats
– determine the rate and regularity of the paced interval
– measure the hysteresis - the period between an intrinsic beat and the next paced beat
Evaluate the escape interval
Evaluate the strip for failure to capture, failure to sense, oversensing, and failure to pace

Pacemakers (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions