Defibrillators, Pacemakers, etc. Flashcards
1
Q
What does CRMD stand for?
A
Cardiac rhythm management devices
2
Q
A dual chamber pacemaker paces the:
A
Right atrium and right ventricle
3
Q
In a dual chamber pacemaker, the pacing leads of the pacemaker are placed in the:
A
right atrium and right ventricle
4
Q
The basic structure of a pacemaker consists of:
A
a pacemaker and pacing leads
5
Q
What are the dimensions of a modern day pacemaker?
A
2 g, 1 cc
6
Q
What is sinus node disease?
A
Symptomatic diseases of impulse formation
7
Q
Symptomatic diseases of impulse formation:
A
Sinus node disease
8
Q
Define sinus node disease:
A
Symptomatic diseases of impulse formation
9
Q
Name that classifies any symptomatic disease of impulse formation
A
Sinus node disease
10
Q
Sinus node disease implies a problem with:
A
impulse formation
11
Q
Impulse formation is negatively affected in what type of disease?
A
Sinus node disease
12
Q
Define diseases of atrioventricular node:
A
Symptomatic diseases of impulse conduction
13
Q
Impulse formation is affected by? Impulse conduction?
A
Impulse formation: sinus node diseases
Impulse conduction: diseases of the atrioventricular node
14
Q
Symptomatic diseases of impulse conduction
A
Diseases of the atrioventricular node
15
Q
The atrioventricular node is to impulse ___________ as the sinus node is to impulse ________.
A
AV node: impulse conduction
Sinus node: impulse formation
16
Q
Impulse conduction is impaired by what types of diseases?
A
Diseases of the atrioventricular node
17
Q
Diseases of the atrioventricular node are defined by:
A
Symptomatic diseases of impulse conduction
18
Q
For what two reasons do most patients have pacemakers?
A
Sinus node disease and atrioventricular disease
19
Q
HRS stands for:
A
Heart rhythm society
20
Q
BPEG stands for:
A
British Pacing and Electrophysiology Group
21
Q
NBG stands for:
A
NASPE and BPEG Generic
22
Q
What are HRS, BPEG, and NBG?
A
Pacemaker classification systems
23
Q
Three types of pacemaker classification systems?
A
BPEG, NBG, NASPE
24
Q
Classification of bradycardia support pacemakers: Positions 12345
A
1) What does it pace?
2) What does it sense?
3) How does it respond?
4) Programmable
5) Multisite pacing
25
Classification of bradycardia support pacemakers: 1
```
1) What does it pace?
V: Ventricle
A: Atria
D: Dual
O: None
```
26
Classification of bradycardia support pacemakers: 2
```
2) What does it sense?
V: Ventricle
A: Atrial
D: Dual
O: None
```
27
Classification of bradycardia support pacemakers: 3
```
3) How does it respond?
I: Inhibited
T: Triggered
D: Dual
O: None
```
28
Classification of bradycardia support pacemakers: 4
4: Programmable
R: Rate modulated
O: None
29
Classification of bradycardia support pacemakers: 5
```
5: Multisite pacing
V: Ventricle
A: Atrial
D: Dual
O: None
```
30
Of the classification of bradycardia support pacemakers, what three groups will you deal with in the OR?
1: What does it pace?
2: What does it sense?
3: How does it respond?
31
123 of bradycardia support pacemakers?
1: What does it pace?
2: What does it sense?
3: How does it respond?
32
What are the possible responses of a bradycardia support pacemaker?
Inhibited
Triggered
Dual (Inhibited + Triggered)
O (None)
33
Position 1 in bradycardia support pacemakers:
Pacing chambers
34
Position 2 in bradycardia support pacemakers:
Sensing chambers
35
Position 3 in bradycardia support pacemakers:
Responses to sensing
36
Position 4 in bradycardia support pacemakers:
Programmability
37
Position 5 in bradycardia support pacemakers:
Multisite pacing
38
Which position in bradycardia support pacemakers refers to multisite pacing?
Position 5
39
Which position in bradycardia support pacemakers refers to programmability?
Position 4
40
Which position in bradycardia support pacemakers refers to response to sensing?
Position 3
41
Which position in bradycardia support pacemakers refers to chambers sensed?
Position 2
42
Which position in bradycardia support pacemakers refers to chambers paced?
Position 1
43
What is multisite pacing?
Pacing electrodes are placed at multiple sites within a particular chamber or on both chambers of the same pedigree
44
Pacing electrodes are placed at multiple sites within a particular chamber or on both chambers of the same pedigree
Multi-site pacing
45
T/F: Multi-site pacing is pacing electrodes placed at multiple sites in two different chambers
False; multi-site pacing is pacing electrodes placed at multiple sites within a particular chamber or on both chambers of the same pedigree
46
"Rate modulation" refers to which position on a bradycardia support pacemaker?
Position 4: programmability
47
"Inhibited" means:
withhold a pacemaker output in response to a sensed event
48
What does "withhold a pacemaker output in response to a sensed event" mean?
Position 3: Response to sensing, inhibited
49
What all is included the "dual" mode of response to sensing?
Inhibiting the pacemaker response
Tracking the sensed event
Inhibit the output on the sensed channel and triggering an output to maintain AV synchrony
50
What is the "triggered" mode of response to sensing?
The pacing device emits a pulse only in response to a sensed event
51
What mode of response to sensing is used when the device is being tested?
Triggered
52
Explain an example DDD.
Sensed atrial signal will cause the device to inhibit atrial output. A timer starts that will cause a triggered ventricular output after a certain interval, but if a patient has an R wave during the triggered interval the ventricular output will be inhibited
53
What are the three asynchronous modes of a pacemaker during application of a magnet?
AOO: fixed rate atrial pacing
VOO: fixed rate ventricular pacing
DOO: fixed rate AV sequential pacing
54
AOO:
fixed rate atrial pacing
55
VOO:
fixed rate ventricular pacing
56
DOO:
fixed rate AV sequential pacing
57
Fixed rate AV sequential pacing:
DOO
58
When are most pacemakers asynchronous?
During application of a magnet
59
When a magnet is placed over a pacemaker, what possible modes occur?
DOO: fixed rate AV sequential pacing
AOO: fixed rate atrial pacing
VOO: fixed rate ventricular pacing
60
Main characteristics of DDD?
Paces atrium and ventricles
| Senses atrium and ventricular signals
61
In DDD, a sensed atrial signal will cause:
the device to inhibit atrial output
62
In DDD, what causes the device to inhibit atrial output?
Sensed atrial signal
63
In DDD, what occurs after a sensed atrial signal causes the pacemaker to inhibit atrial output?
A timer starts that will cause a triggered ventricular output after a certain interval
64
In DDD, what occurs if a patient has an R wave during the triggering interval?
The ventricular output is inhibited
65
In DDD, what aspects do pacemakers inhibit?
Once atrial activity is sensed, an atrial output is inhibited for the sake of pacemaker control. Ventricular output is also inhibited if a patient has an R-wave during a set triggering interval.
66
In DDD, what aspects do pacemakers trigger?
A pacemaker starts a timer for a set interval after which a ventricular output is triggered.
67
Which mode paces atrium and ventricles + senses atrium and ventricular signals?
DDD
68
What pacing mode are most pacemakers?
Most pacemakers are dual chamber (AV).
69
AOO:
Atrial asynchronous pacing
70
VOO:
Ventricular asynchronous pacing
71
DOO:
Dual-chamber (AV) asynchronous pacing
72
AAI:
Atrial-inhibited pacing
73
VVI:
Ventricle-inhibited pacing
74
VAT:
Atrial triggered, ventricular pacing
75
VDD:
Atrial triggered, ventricular-inhibited pacing
76
DVI:
Dual-sequential, ventricular-inhibited pacing
77
DDI:
Dual chamber, dual-sequential pacing
78
DDD:
Dual-sequential, atrial trigger, ventricular inhibited pacing or AV universal pacing
79
How many possible pacing modes for bradycardia are there?
10
80
In what form does a pacemaker jolt appear on an EKG? Why?
As a PVC because the electrical impulse always originates from somewhere other than the SA node (so an unnatural path)
81
What is a biventricular pacemaker?
BiV or Cardiac resynchronization therapy (CRT): The pacemaker paces the right and left ventricle as well as the right atrium.
82
How many leads does a biventricular pacemaker have? Where are they placed?
Three:
One is placed in the right atrium.
One is placed in the right ventricle.
The left ventricular lead is actually placed in the coronary sinus.
83
T/F: the left ventricular lead of a biventricular pacemaker is placed at the base of the left ventricle of the heart.
False; it is actually placed in the coronary sinus.
84
What is the main function and benefit to a biventricular pacemaker?
A biventricular pacemaker sends small electrical impulses to the lower chambers of the heart to help them beat in a more synchronized pattern
85
Two parts of biventricular (CRT) system?
1) Heart device + battery
| 2) Leads
86
Two types of biventricular (CRT) devices?
```
CRT pacemaker (CRT-P)
CRT defibrillator (CRT_D)
```
87
Another name for endocardial leads?
Transvenous leads
88
Two ways to secure endocardial (transvenous) leads?
Active fixation: metal screw-in
| Passive fixation: rubber fins or tines
89
If you secure an endocardial lead using metal screw-in, what type of fixation is that?
Active fixation
90
If you secure an endocardial lead using rubber fins or tines, what type of fixation is that?
Passive fixation
91
Which type of lead polarity is most reliable?
Unipolar
92
Which type of lead polarity has improved rejection for better sensing?
Bipolar
93
Which portion of the pacemaker leads are unipolar?
Case + lead tip
94
Which portion of the pacemaker leads are bipolar?
Lead tip
95
Benefit to unipolar leads?
Highest reliability
96
Benefit to bipolar leads?
Improved rejection for better sensing
97
Which lead EKG tracing has larger pacing artifacts on it, bipolar or unipolar? Why?
Unipolar; there is a larger pacing circuit on unipolar leads, so there is larger pacing artifact.
98
Which type of lead is the spare in epicardial pacemakers?
The bipolar lead is the spare in case the working lead (unipolar) no longer functions.
99
How do leadless pacemakers function in the heart?
Leadless is a bit of a misnomer because the right ventricle is still stimulated by a lead. Once the pulse generator picks up on the electrical activity of the pacemaker, it sends an ultrasonic wave into a leadless electrode implanted in the LV.
100
Where are leadless electrodes typically implanted?
LV
101
In a bipolar temporary pacing electrode, which portion of the lead is positive and which is negative?
The tip electrode is negative and the ring electrode is positive.
102
Why is it customary to consider the tip electrode negative in a bipolar temporary pacing electrode?
Cathodal pacing has a lower threshold (minimum voltage required for capturing the chamber paced).
103
What patients would receive a pacemaker with VDD settings? (Pacing in triggered and inhibited mode)
A patient with a functioning SA node but a non-functioning AV node
104
What is the difference between the EKG tracings of VAT and VOO?
Both demonstrate spontaneous atrial activity and paced ventricular activity, but the equal PR intervals throughout every beat in VAT mode is the primary difference.
105
What type of pacing adjusts heart rate to level of activity?
Rate responsive (modulation) pacing
106
What are the two types of activity sensors in rate responsive (modulation) pacing?
Motion (vibration)
| Ventilation (bioimpedance)
107
Motion (vibration) correlates to which sensor status in rate responsive (modulation) pacing?
G sensor (accelerometer)
108
Ventilation (bioimpedance) correlates to which sensor status in rate responsive (modulation) pacing?
MV sensor
109
Which is higher at baseline in rate responsive (modulation) pacing, G sensor or MV sensor?
G sensor (accelerometer)
110
What is the general recommendation for rate responsive pacemakers during surgery? Why?
Generally understood to turn them off to prevent confusion between inherent tachycardia and pace-maker induced tachycardia
111
Why is pacemaker-induced tachycardia a common issue with rate responsive pacing during surgery?
The sensor that measures minute ventilation is extremely sensitive to stray electromagnetic interference; the pacemaker misunderstands the interference to be an increase in minute ventilation (increased activity) and increases the HR in response.
112
Which sensor in rate responsive pacing provides a fast response at beginning of exercise and indicates end of exercise?
G sensor (accelerometer)
113
Function of G sensor in rate responsive pacing?
Provides a fast response at beginning of exercise and indicates end of exercise
114
Which sensor in rate responsive pacing provides a physiological and gradual response to exercise, detects increase in metabolic need and adapts pacing rate in proportion to exercise?
MV sensor (minute ventilation)
115
Function of MV sensor in rate responsive pacing?
Provides a physiological and gradual response to exercise, detects increase in metabolic need and adapts pacing rate in proportion to exercise
116
In rate responsive pacing, there is often bioimpedance between:
Which sensor senses bioimpedance?
Bioimpedance between atrial lead and body of pacemaker
| Sensed by the MV sensor (minute ventilation, bioimpedance)
117
Name some surgical situations in which pacemakers should be reprogrammed prior to surgery.
```
Any rate responsive device
Special pacing indication, HOCM, DCM, etc.
Pacemaker-dependent patients
Major procedures in chest + abdomen
Rate enhacements
Lithotripsy
Transurethral resection
Hysteroscopy
ECT
Succinylcholine use
MRI
```
118
What does Biggs want you to remember about what kind of steps to take w/ patients w/ pacemakers preoperatively?
1. Identify whether or not the patient has a pacemaker or a defibrillator.
2. Have the pacemaker or defibrillator interrogated.
3. Obtain a copy of this interrogation.
4. Determine the patient's underlying rate and rhythm.
5. Identify the magnet rate and rhythm, if any.
6. Turn minute ventilation rate responsiveness off.
7. Program all rate enhancements off.
119
What does Biggs want you to remember about what kind of steps to take w/ patients w/ pacemakers intraoperatively?
1. Monitor cardiac rhythm with pulse ox or A-line.
2. Ask the surgeon to not use monopolar ESU.
3. Use bipolar ESU if possible; if not, a pure cut is better than a "blend" or a "coag".
4. Place ESU return pad.
5. If ESU causes oversensing, limit periods of asystole.
120
What is the major first thing you MUST do after surgery w/ patient w/ pacemaker?
Have pacemaker interrogated.
121
What is the general rule if the surgeon must use a monopolar ESU on a patient w/ pacemaker?
Clean cuts are better than "blends" or "coags".
122
The parts of the preanesthetic pulse generator evaluation that Biggs wants you to know:
1) Identify type of device
2) Determine patient's underlying rhythm
3) Obtain history of generator events
4) Interrogate the device
5) Ensure magnet detection is enabled.
123
What is "blend" on an ESU?
A broad radiofrequency
124
HRS stands for:
Heart rhythm society
125
Biotronik is asynchronous at what rate:
Asynchronous pacing at 90 bpm (DOO or VOO)
126
Boston Scientific is asynchronous at what rate:
Asynchronous pacing at 100 bpm (DOO with maximum AV delay or VOO)
127
ELA/Sorin is asynchronous at what rate:
Asynchronous pacing at 96 bpm (DOO with maximum AV delay or VOO)
128
Medtronic is asynchronous at what rate:
Asynchronous pacing at 85 bpm (DOO or VOO)
129
Which pacemaker type is asynchonous in DOO or VOO?
Medtronic + Biotronik + St. Jude Medical
130
Which pacemaker type is asynchronous in DOO with maximum AV delay or VOO?
ELA/Sorin or Boston Scientific
131
St. Jude Medical is asynchronus at what rate:
100 bpm
132
Temporary internal pacing is done via what type of catheter?
Bipolar RV pacing catheter
133
T/F: sometimes, instead of using a bipolar RV pacing catheter, temporary pacing will utilize a Swan-Ganz catheter.
True
134
How many electrodes on an SG catheter can pace the heart?
5
135
Where are atrial leads located on a SG catheter?
At 30 cm mark
136
Why are there more atrial leads than ventricular?
It is more difficult to capture the atria than the ventricle.
137
Temporary (internal) pacing: when an electrode is placed in the esophagus, what portion of the heart is it reading?
Left atrium
138
Temporary (internal) pacing: when an electrode is placed in the stomach, what portion of the heart is it reading?
Ventricle
139
When using a defibrillator, what are the three main steps?
1. Select the size of the charge you wish to deliver.
2. Charge the defibrillator.
3. Deliver a shock if necessary.
140
Besides producing an EKG, what are three other forms of monitoring that a defibrillator is capable of?
CO2
SPO2
NIBP
141
On your standard defibrillator, which button should you press to take an NIBP reading?
The button on the lower right of the screen
142
What is "M" on a paced EKG?
Timing mark: defines when a shock will be applied in the cardiac cycle
143
Why must the timing mark avoid the T-wave?
A shock during this period may fibrillate the ventricles (torsades)
144
If someone references the "vulnerable period" of an EKG, they are referring to:
T-wave (ventricular repolarization)
145
What does AICD stand for?
Automatic implantable cardio-defibrillator
146
What are the four functions of an AICD?
Antitachycardic pacing
Cardioversion
Defibrillation
Bradycardia pacing
147
What does NASPE stand for?
North American Society for Pacing and Electrophysiology
148
What does NBD stand for?
NASPE/BPEG defibrillator
149
How many positions does the NBD have?
4
150
What are the four positions of the NBD?
1) Where does it shock?
2) Antitachycardic chambers
3) Tachycardia detection
4) Antibradycardia pacing chambers
151
Which positions on NBD have VADO as options?
1) Where does it shock?
2) Antitachycardic chambers
4) Antibradycardic pacing chambers
152
Possible actions of third position of NBD (tachycardia detection)?
E: electrogram
H: hemodynamic
153
Antitachycardic functions of defibrillators (ICD/CRT):
```
P = Pace heart out of tachycardic rhythm
S = Shock the heart
D = Dual, paced and shocked
O = none
```
154
Most common antitachycardia function of CRT (a bradycardia device)?
O = none
155
Most common antitachycardia function of ICD?
D = Dual, paced and shocked
156
Pacer-cardioverter-defibrillators are usually placed in the:
abdomen
157
How do pacer-cardioverter-defibrillators work?
The pulse generator receives information from two sensing leads and delivers precisely programmed electrical impulses to the heart through two or three patch leads.
158
Describe the latest transvenous fibrillation systems:
A single catheter in the right ventricular apex
159
Why don't these devices burn holes in the SVC when they deliver shocks?
They only deliver a shock for a small amount of time to prevent the tissue from burning.
160
In a defibrillator, what type of electrode is the RV pacing electrode?
It is pacing/sensing/shock electrode; integrated bipolar
161
Purpose of SVC electrode in defibrillator?
Shock, only shock
162
Function of tip electrode of a defibrillator?
Sensing/Pacing
| Tined lead
163
Where does a true bipolar lead sense?
Between the distal tip and the proximal ring
164
How many coils do true bipolar leads have?
A single coil
165
Where do integrated coil leads pace and sense?
Between the tip and the distal coil
166
By what means is the distal coil useful?
Used for sensing, pacing, and defibrillation
167
What is the purpose of the second, more proximal coil in integrated leads?
Increases lead surface area for defibrillation
168
Normal shock for a defibrillator is how many Joules?
10-30 J
169
T/F: Medication is actually proven to be more effective as an using a defibrillator.
False; defibrillators reduce death 39% in the first year.
170
If the patient is in V-tach, should you cardiovert or defibrillate them?
You can technically cardiovert V-tach as long as you time the shock immediately after ventricular depolarization.
171
If the patient is in V-fib, should you cardiovert or defibrillate them?
Defibrillate them
172
Which is more efficient at depolarizing the heart, a biphasic or monophasic defibrillator waveform?
Biphasic
173
Maximum amount of energy you can use in a biphasic delivery for defibrillation?
200 J
174
Maximum amount of energy you can use in a biphasic delivery for synchronized cardioversion?
200 J
175
Maximum amount of energy you can use in a biphasic delivery for internal defibrillation?
50 J
176
How much more energy can monophasic defibrillation safely deliver than biphasic?
None--they can both deliver a maximum of 50 J.
177
Steps in energy delivery for defibrillation (biphasic)?
120, 150, 200, 200 J
178
Steps in energy delivery for synchronized cardioversion (biphasic)?
70, 120, 150, 200 J
179
Steps in energy delivery for pediatric defibrillation (biphasic)?
2 J/ kg
180
Steps in energy delivery for internal defibrillation (biphasic)?
5, 10, 20, 30, 50 J
181
Internal defibrillator panels are placed directly across the heart and deliver a shock of:
10-30 J
182
How does placing a magnet affect ELA/Sorin pacing function?
Magnet rate changes but continues in DDD mode (from 96 to 80 bpm)
183
Which common pacemakers have a tone with magnet placement?
Medtronic, Boston Scientific
