Brainscape's Knowledge GenomeTM

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


See full index

NSCC 7150 > Pacemaker Therapy > Flashcards

Pacemaker Therapy Flashcards

1
Q

pacemakers

A

deliver electrical stimulus to cardiac tissue triggering depolarization and contraction

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

categories of pacemakers

A
  • temporary or permanent pacemaker
  • types of temporary pacemakers
  • types of pacing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

permanent pacemakers

A
  • used when pts experience permanent and hemodynamic-compromising bradydysrhythmias
  • implanted under the skin and SC tissue in the upper chest area or upper abdomen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

leadless pacemaker

A

implanted directly into heart with no separate incision under skin

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

temporary pacemakers

A
  • used in emergency situations or when the bradydysrhythmias are believed to be transient
  • most is external to pt
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

type of temporary pacemakers

A
  • transvenous (via lead inserted through large vein into the heart)
  • transcutaneous (via electrode pads attached to chest wall)
  • epicardial (via temporary, fine wires that are attached to the epicardium placed during open heart surgery)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how can pacemakers pace the heart?

A
  • single-chamber pacing, where one chamber of the heart is paced (i.e., ventricle or atria)
  • dual-chamber pacing, where two chambers of the heart are paced (i.e., ventricle and atria)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

indications for pacemaker therapy

A

to manage select cardiac dysrhythmias and to enhance cardiac output

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

indications for pacing

A
  • sinus brady or arrest
  • AV blocks
  • MI or ischemia that results in AV blocks or dysrhythmias
  • post-cardiac surgery that disrupts conduction
  • sick sinus syndrome
  • tachydysrhythmias where there is an unnaturally fast rate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does the pacemaker system comprise of?

A

pulse generator (power source) and one or more pacing leads; with permanent, both are internal; when external pacemakers, a connecting cable is needed

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

what does the pulse generator do?

A
  • generate electrical impulses when heart doesn’t generate its own impulse or fires at a low rate
  • also capable of sensing the heart’s intrinsic electrical impulses or rhythm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

the electrical impulse generated by the ____ is transmitted via ______ which are in direct contact with ______

A

pulse generator; the pacing leads; either the atrial or ventricular chambers (single chamber) or both (dual chamber)

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

can dual chamber pulse generator be used for both single or dual chamber pacing?

A

yes

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

components of pulse generators

A
  • on/off switch
  • pulse generator cover
  • sense/pace lights
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

sense light versus pace light

A

sense light is normally orange and lights up when pacemaker senses an intrinsic depolarization

pace light is normally green and is activated when the pacemaker emits an impulse to pace

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

pacemaker settings

A

-HR: set according to pt’s needs to maintain adequate CO; usually 60-80bpm; measured as pulses/min to distinguish between intrinsic HR and artificially generated ones

  • output or mA
  • sensitivity (mV)
  • demand (or synchronous) pacing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

output or mA

A
  • strength of the electrical impulse delivered to the cardiac tissue to initiate a depolarization (measured in mA)
  • appropriate mA or output levels are determined by increasing the mA while watching the patient’s ECG, looking for evidence of paced beats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

pacing threshold

A

Once a paced rhythm is achieved, the output level is noted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is mA usually set at?

A

~2 to 3 times the pacing threshold, allowing for changes in the pacing threshold

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

sensitivity

A

the amount of electrical activity that needs to be generated during a patient’s intrinsic depolarization for the pacemaker to sense it (measured in mV)

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

why is sensitivity an important setting?

A
  • it allows the pacemaker to work in sync with the pt’s own electrical activity
  • when pacemaker senses the pt’s intrinsic cardiac activity, it will respond in a pre-programmed manner—usually by inhibiting itself from firing, which avoids issues such as firing on a patient’s T wave
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what if the mV setting is higher?

A

the larger the amount of electrical activity the heart has to generate during its intrinsic depolarization for the pacemaker to recognize it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

high mV settings indicate?

A

pacemaker is less sensitive to pt’s intrinsic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

low mV settings indicate?

A

pacemaker is more sensitive to pt’s activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

sensing threshold

A

the level of mV at which the pacemaker can sense the patient’s intrinsic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how do you decide on an appropriate setting for sensitivity?

A

determine sensing threshold and set it at half of that level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

demand or synchronous pacing

A
  • when a pacemaker’s sensitivity setting allows it to sense the pt’s intrinsic activity (and respond to that sensed activity by inhibiting itself from firing)
  • preferred method
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

fixed or asynchronous pacing

A
  • pacemaker does not respond to any intrinsic heart activity even if it is occurring
  • typically used in emergency situations or if the patient is known to have no underlying heart rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

pacing lead

A
  • carries “sensed” info from the heart to the pulse generator
  • has a positive and a negative electrode
  • current flows from negative connector to negative electrode and travels back via positive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the most common route for temporary pacing?

A

transvenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

which veins is transvenous pacing lead threaded through?

A

femoral, subclavian, IJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is important about insertion? what does the nurse do?

A
  • CVC must be inserted first
  • comfort, supine, meds to help relax, continuous ECG monitoring + VS
  • ensure pacing lead and pulse generator secured to prevent dislodgement
33
Q

what is most commonly used in emergency situations and why?

A

transcutaneous approach b/c its non-invasive, does not require central line access, and can be initiated quickly

34
Q

where do the electrode pads go for transcutaneous pacing?

A

chest wall; similar to where pads go for defib

35
Q

what is the physiology of transcutaneous pacing?

A

an electrical impulse is generated by an external pulse generator to depolarize the cardiac cells. This impulse is transmitted through the chest wall to the heart via skin contact pads

36
Q

what is important to ensure with transcutaneous pacing and why?

A

patient comfort through analgesia or sedation b/c:

  • electrical energy or output (mA) required in transcutaneous pacing tends to be larger than with transvenous pacing because it has to travel through the patient’s chest wall before it can depolarize cardiac cells
  • larger mA also depolarizes the skeletal chest muscle tissue
  • pt will experience skeletal muscle contractions at the set rate of the transcutaneous pacemaker = very painful
37
Q

nursing considerations when initiating transcutaneous pacing

A
  • clipping excess hair for placement of pads
  • placing pads on clean, dry skin
  • keeping pt in supine
  • giving meds to help pt relax and warn them of discomfort
  • following doctor’s orders for settings based on pt response to therapy
38
Q

what does the rate default the capture to on the monitor?

A

70mA; can change it by turning dial clockwise (normal range for capture is 40-80mA)

39
Q

what will happen when you obtain capture?

A

you will overshoot pt’s threshold and need to turn down output; decrease output slowly until you just lose capture

40
Q

what is the patient’s threshold?

A

minimum output that obtains capture

41
Q

what do you do with output once pacing is determined?

A

set output to 10% above that threshold

42
Q

how can mechanical capture be confirmed?

A

by physically palpating a femoral or R radial brachial pulse (avoid ax carotid/L radial arteries, muscular contractions from pacing pulse may cause misinterpretation)

43
Q

nursing considerations when monitoring transcutaneous pacing are?

A
  • checking pacing pads to ensure they’re not drying out and losing contact with the skin surface
  • repositioning pt but making sure they do not get up and walk around as this could disrupt lead contact
  • ensuring pt comfort, particularly if they are experiencing skeletal muscle contraction with pacing stimulus
  • monitoring ECG waveform, VS, and pt’s condition to ensure adequate and effective pacing
44
Q

what does the NBG code convey info about?

A

the pacemaker’s pacing, sensing, and response functions. It applies to both temporary and permanent pacemakers

44
Q

how many letters are important in temp pacemaking vs permanent?

A

3 letters in temp; 5 in permanenet

45
Q

what do the first three letters of the NBG code stand for?

A

1 = heart chamber(s) paced
2 = heart chamber(s) where intrinsic electrical activity is sensed
3 = pacemaker’s response when it senses intrinsic electrical activity

46
Q

what does letter four and five stand for?

A

4 = capacity for rate modulation
5 = multisite pacing

47
Q

1 = chamber paced
2 = chamber sensed

A

A: atrium
V: ventricle
D: Dual (A or V)
0 = none

48
Q

3 = response to sensing

A

I: Inhibited
T: Triggered
D: Dual (inhibited & triggered)
0 = none

49
Q

atrial pacing is achieved by? and may be used when?

A

placing a pacing lead in the right atria; when SA node is diseased or damaged by requires normal conduction through AV node and ventricles

50
Q

why is atrial pacing rarely used in transvenous pacemakers?

A
  • pacing lead is large, risk of perfing the thinner atrial walls = cardiac tamponade
  • difficult to keep pacing lead secured situated in the atria
51
Q

what is the common NBG code in atrial pacing?

A

AAI
- pacemaker pacing atria
- senses intrinsic electrical activity in atria
- will be inhibited from firing when it senses intrinsic activity

52
Q

ventricular pacing in a transvenous pacemaker requires?

A

placement of a pacing lead in the right ventricle; most common site for transvenous placing

53
Q

common NGB code for ventricular pacing is ?

A

VVI
- pacemaker is pacing ventricle
- senses intrinsic electrical activity in ventricle
- inhibited from firing when it senses intrinsic activity

54
Q

what is important to recognize in VVI pacing about the pacemaker?

A

it does not communicate with the atria as lead is in the ventricle = pacemaker is unaware of atrial depolarization and has no way of coordinating or synchronizing paced ventricular activity with the pt’s intrinsic atrial activity = asynchronous contraction of the atria and ventricles = decrease in atrial kick, preload and CO

55
Q

what does electrical discharge from a cardiac pacemaker produce on an ECG strip?

A

spike or artifact

56
Q

a pacemaker with a lead placed in the atria shows what on an ECG?

A

spike followed by a P wave

57
Q

a pacemaker with a lead placed in the ventricle shows what on an ECG?

A

spike followed by a QRS complex that is wide and bizarre b/c ventricular depolarization from pacing does not follow the normal conduction pathway

58
Q

common pacemaker malfunctions

A
  • failure to pace
  • failure to capture
  • inappropriate sensing
59
Q

what is failure to pace and how would it look on an ECG strip?

A

failure of the pulse generator to emit an electrical impulse; would see no pacer spikes on ECG strip

60
Q

causes of failure to pace

A
  • low battery power in pulse generator
  • circuitry failure
  • overall malfunction in pacemaker
  • broken pacing lead *light will still flash
  • disconnection in system *light will still flash
61
Q

troubleshooting failure to pace

A
  1. assess battery strength and fx of pulse generator
  2. check connections between pulse generator, connecting cable and pacing wire
  3. consider # in pacer wire
  4. notify doctor, if pt symptomatic = emergency
62
Q

what is failure to capture and how does it show on an ECG strip?

A
  • occurs when the electrical impulse is emitted from the pulse generator but fails to depolarize the myocardium
  • will see a spike alone/without a waveform (not follow by P or QRS)
63
Q

causes of failure to capture

A

can be caused by anything that increases the difficulty of the electrical impulse delivered from the pulse generator to induce depolarization of the cardiac cells

  • acidosis, electrolyte imbalance, and myocardial ischemia, or can be pacer-related issues, such as a mispositioned pacer leading to poor contact with the chamber tissue or inadequate mA (output) setting
64
Q

troubleshooting failure to capture

A
  1. reposition pt in attempt to float pacing lead closer to interior chamber walls
  2. increase output setting on pulse gen until capture is achieved.
  3. review pt info for evidence of pt-related issues and intervene accordingly
  4. notify doctor
65
Q

inappropriate sensing or failure to sense

A

consists of oversensing and undersensing

66
Q

oversensing

A
  • occurs when the pacemaker senses extraneous, non-cardiac electrical signals ie) muscle tremors cause pacemaker to be inappropriately inhibited or triggered
  • pacemaker is too sensitive
67
Q

oversensing on an ECG strip

A
  • may be present where pacing should have occurred (will see long pauses)
  • can look like failure to pace
68
Q

how to differentiate oversensing from failure to pace?

A

alter the sensitivity setting and watch the response on the patient’s ECG. To decrease the sensitivity setting, increase the mV. This means that a larger amount of electrical activity is required for the pacemaker to become aware of intrinsic electrical activity. If normal pacer function is restored, then the issue was oversensing

69
Q

undersensing

A
  • pacemaker is too insensitive
  • sensitivity setting requires larger intrinsic electrical activity for the pacemaker to recognize it
  • high possibility of pt’s intrinsic activity not being sensed
  • puts pt at risk of R-on-T phenomenon
70
Q

R-on-T phenomenon

A
  • occurs when a pacing stimulus is delivered during the downslope of the T wave, when the heart is in the relative refractory period and is not fully repolarized but is capable of responding to a stimulus
  • can precipitate life-threatening dysrhythmias
71
Q

how will undersensing show on ECG?

A

pacer spikes are out of place; may occur in middle of QRS complex or immediately after an intrinsic beat

72
Q

causes of undersensing

A
  • inappropriate sensitivity settings *troubleshoot by adjusting sensitivity setting
  • lead displacement
  • loose cable connections
73
Q

what’s different about a paced QRS and regular QRS?

A

paced QRS is wide and bizarre

74
Q

how do you name a paced rhythm?

A

examples:
- ventricular pacing with failure to capture (sixth beat)
- ventricular pacing with failure to sense
- atrial pacing with six-second period of failure to pace
- sinus rhythm with occasional ventricular-paced beats
- ventricular-paced rhythm with occasional intrinsic beats

75
Q

failure to pace interventions

A
  • Check pt (ABC)
  • Change pulse generator battery
  • Check all connections.
  • Check the integrity of pacing leads
  • Call doctor
76
Q

failure to capture interventions

A
  • Check pt (ABC)
  • Check cable connections.
  • Reposition pt to ensure pacing lead has contact with the heart.
  • Increase output (mA) if in line with agency’s policy.
  • Call the doctor if needed
77
Q

failure to sense interventions

A
  • Check pt (ABC).
  • Adjust sensitivity (mV).
  • Eliminate electrical interference
  • Reposition pt to ensure pacing lead is in contact with heart

NSCC 7150 (11 decks)

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