Know this! Flashcards
(226 cards)
1
Q
S1 heart sound is caused by?
A
Atrial-Ventricular (AV) valve closure (tricuspid/bicuspid)
2
Q
Where is S1 heard the loudest?
A
- at the apex of the heart
- midclavicular, 5th intercostal space
- mitral area
3
Q
Which heart sound marks the end of diastole and beginning of systole?
A
S1 heart sound
4
Q
S2 heart sound is caused by?
A
- closure of semilunar valves (aortic/pulmonic)
- aortic valve (A2), pulmonic valve (P2)
- A2 closes B4 P2, but to close so sounds like one sound
5
Q
Where is S2 heard the loudest?
A
- at the base of the heart
- right sternal border, 2nd intercostal space
- aortic area
6
Q
Which heart sound marks the end of systole and beginning of diastole?
A
S2
7
Q
When does S2 split normally?
A
- during inspiration
8
Q
A wide, fixed splitting of S2 is caused by?
A
Right Bundle Branch Block
9
Q
A pulmonary embolism causes which heart sound to be heard more loudly?
A
- S2
- causes an increase in back pressure in pulmonary artery and pushes back on pulmonic valve causing stronger closure and louder sound
10
Q
What are the auscultatory points of the heart?
A
- Aortic
- Pulmonic
- Erb’s point
- Tricuspid
- Mitral
11
Q
S3 heart sound is caused by?
A
- caused by the rapid rush of blood into a dilated ventricle
- occurs early in diastole, right after S2
12
Q
Where is S3 heard the loudest?
A
- heard best at the apex of the heart with the bell of the stethoscope
13
Q
S3 is associated with?
A
- heart failure
- pulmonary HTN
- cor pulmonale
- mitral, aortic, or tricuspid insufficiency
14
Q
S4 heart sound is caused by?
A
- atrial contraction of blood into noncompliant ventricle
- occurs right after S1
15
Q
Where is S4 heard the loudest?
A
- at the apex with the bell of the stethoscope
16
Q
S4 is associated with?
A
- myocardial ischemia
- infarction
- HTN
- ventricular hypertrophy
- aortic stenosis
17
Q
What BP changes are seen with severe hypovolemia or a severe drop in cardiac output?
A
severe hypovolemia or a serve drop in cardiac output
18
Q
Systolic blood pressure is an indirect measurement of which hemodynamic measurement?
A
cardiac output and stroke volume
19
Q
Diastolic blood pressure is an indirect measurement of which hemodynamic measurement?
A
systemic vascular resistance
20
Q
The coronary arteries are perfused during which cardiac phase?
A
diastole
21
Q
Why does inspiration cause an S2 split?
A
- inspiration causes increased venous return to heart
- increased volume = RV takes longer to empty
- longer empty = SL valve stays open longer
22
Q
Where is the aortic area located on the chest?
A
2nd ICS along the left sternal border
23
Q
Where is the pulmonic area located on the chest?
A
2nd ICS along the right sternal border
24
Q
Where is Erb’s point located on the chest?
A
3rd ICS along the left sternal border
25
Where is the tricuspid area located on the chest?
4th ICS along the left sternal border
26
Where is the mitral area located on the chest?
5th ICS, mid-clavicular
27
Where is the S2 split and P2 sound heard the best?
upper left sternal border
28
Pts with documented symptomatic bradycardia fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
29
Pts with chronotropic incompetence fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
30
Pts with drug induced symptomatic bradycardia fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
31
Pts with SND w/ HR <40 and significant brady-like symptoms but with no documented association with the presence of bradycardia fall under what recommendation class for placement of a permanent pacer?
Class IIa
| implantation is reasonable
32
Pts experiencing syncope of unexplained origin and the discovery of clinically significant abnormalities of SN function fall under what recommendation class for placement of a permanent pacer?
Class IIa
| implantation is reasonable
33
Pts with minimally symptomatic patients w/ chronic HR <40 while awake fall under what recommendation class for placement of a permanent pacer?
Class IIa
| PM may be considered
34
Term referring to a broad array of abnormalities r/t sinus node and atrial impulse formation and propagation?
Sinus Node Dysfunction
35
What are the anatomic locations an AV block may occur?
- supra-His
- intra-His
- infra-His
36
What is the normal value for the PR interval?
120-200 ms
37
Which type of heart block has a constant, prolonged PRI (> 200ms) with no dropped or non-conducted beat?
1st degree AV block
38
What is a the defining characteristic of a 1st degree AV block?
Constant, prolonged PRI (> 200ms) with no dropped or non-conducted beat
39
What is the difference between 2nd degree type I and type II AV block?
- type I: progressive prolongation of the PRI until a beat is dropped
- type II: fixed, prolonged PRI with dropped beat, and is usually associated with a wide QRS
40
Which type of 2nd degree block is usually associated with a wide QRS?
Type II
41
Advanced 2nd degree AV block is described as?
2 or more consecutive P waves w/ nonconducted beats
42
In A-Fib, with a pause greater than 5 seconds should be considered to be d/t which type of heart block?
Advanced 2nd degree AV block
43
Type II 2nd degree AV block usually occurs intra-, infra- or supra-His?
block usually occurs intra- or infra-His, especially when the QRS is wide
44
3rd degree and advanced 2nd degree AV block associated w/ symptomatic bradycardia fall under what recommendation class for placement of a permanent pacer?
Class I
| PM is indicated
45
Pts with ventricular arrhythmias that are presumed to be d/t 3rd degree and advanced 2nd degree AV block fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
46
Pts with symptomatic bradycardia r/t required drug therapy and 3rd or advanced 2nd degree AV block fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
47
PM implantation is indicated for awake, asymptomatic pts in sinus rhythm with documented periods of asystole of what duration?
greater than or equal to 3 seconds
48
PM implantation is indicated in awake, asymptomatic pts with A-fib and bradycardia (tachy-brady) with ____ or more pauses lasting _____?
- 1 or more pauses
| - lasting 5 or seconds
49
Pts with 2nd degree AV block and associated symptomatic bradycardia fall under what recommendation class for placement of a permanent pacer?
Class I
| implantation is indicated
50
Pts with persistent 3rd degree AV block and avg awake HR of ___ BPM are a Class I for PM placement.
HR < 40 BPM
51
Pts with persistent 3rd degree AV block and avg awake HR of > 40 BPM with what conditions are a Class I for PM placement?
if cardiomegaly or LV dysfunction is present
52
Pts with 2nd or 3rd degree AV block during exercise with no myocardial ischemia fall under what recommendation class for placement of a permanent pacer?
Class I, indicating that a PM is needed
53
Asymptomatic pts with persistent 3rd degree AV block and an escape rate >40 without cardiomegaly fall under what recommendation class for placement of a permanent pacer?
Class IIa
| PM may be considered or is reasonable
54
2nd degree AV block at the intra- or infra-His level fall under what recommendation class for placement of a permanent pacer?
Class IIa
| PM may be considered or is reasonable
55
Pts with 1st or 2nd degree AV block w/ symptoms similar to _____ or ______ are Class IIa indications for PM placement.
pacemaker syndrome symptoms or hemodynamic compromise
56
When does type II 2nd degree AV block with a wide QRS become a Class I recommendation for PM placement?
when the pt has isolated right bundle branch block
57
Term for impaired conduction below the AV node in the right and left bundle branches?
Bifascicular block
58
Bifascicular block is the term for which type of impaired conduction?
- when the impaired conduction is located below the AV node in the right and one of the two fascicles of the left bundle branches
- Right and left bundle blocks
59
How many cardiac fascicles are there and what are they called?
- 3 total
- RV x 1: Right Bundle Branch
- LV x 2: anterior and posterior fascicle
60
What type of pacing is indicated for a pt w/ persistent 2nd degree AV block in the His-Purkinje system w/ alternating BBB or 3rd degree block w/in or below the His-purkinje system after a STEMI?
permanent ventricular pacing is indicated
61
What type of pacing is indicated for a pt with transient advanced 2nd or 3rd degree infranodal AV block and associated BBB?
permanent ventricular pacing
62
What is hypersensitive carotid sinus syndrome?
syncope or presyncope resulting from an extreme reflex response to carotid sinus stimulation
63
What are the 2 components of hypersensitive carotid sinus syndrome?
- cardioinhibitory d/t increased parasympathetic tone
| - vasodepressor effect, secondary to above
64
What are the cardioinhibitory manifestations of hypersensitive carotid sinus syndrome?
- asystole d/t either slowing of the sinus rate (sinus arrest) or prolongation of the PR interval
- pauses up to 3 secs during carotid sinus massage are WNL
65
What are the manifestations of the vasodepressor component of hypersensitive carotid sinus syndrome?
loss of vascular tone and hypotension
66
Neurocardiogenic syncope or syndrome is characterized by?
self-limiting episodes of systemic hypotension d/t both bradycardia and peripheral vasodilation
67
Pacing is indicated for pauses lasting _____ in patients with recurrent syncope r/t to hypersensitive carotid sinus syndrome and neurocardiogenic syncope.
pauses lasting longer then 3 seconds
68
When is permanent pacing a reasonable (class IIa) tx for symptomatic recurrent SVT?
when catheter ablation and/or drugs fail to control the arrythmia or produce intolerable side effecgts
69
Pts w/ sustained pause-dependent VT w/ or w/o QT prolongation fall under what recommendation class for placement of a permanent pacer?
Class I
| PM is indicated
70
CRT is indicated for pts with LVEF _1_, sinus rhythm, LBBB with a QRS _2_, and NYHA _3_.
1) less than or equal to 35%
2) greater than or equal to 150ms
3) NYHA class II, III or ambulatory IV
71
What are the pathological causes of abnormal bradycardia?
- SSS
- drugs
- SA block
- sinus arrest and AV block
72
What is overdrive suppression r/t the heart?
The slower AV node (40-60) is suppressed by the faster SA node (60-80)
73
What mode would be set for a patient with normal SA node conduction and AV block?
- Dual chamber pacemaker with VAT or DDD mode
| - Pace (V), Sense (A), Triggered
74
What are the steps of VAT mode starting with the firing of the SA node?
- Steps:
1) SA node fires = atrial PM inhibition and start of AVD
2) AV delay expires = ventricular PM fires = restarts atrial escape interval
75
The AV delay is equivalent to what normal physiologic cardiac interval?
PR interval
76
What is the atrial escape interval (AEI)?
time from begging of QRS or firing of ventricular PM to the next QRS or vent pace
77
What are the modes for a pt with afib or SSS with no hx of AV block with a single chamber pacemaker?
- VVI for A-Fib
| - AAI for SSS and no hx of AV block
78
What does TPS stand for?
Transcatheter Pacing System
79
What type of lead polarity would produce large pacing spikes and pectoral/pocket stimulation?
unipolar leads
80
What is Ohm's law?
V = IR
81
Current is measured in what units and represented by which letter?
milliamps (mA) and represented by I
82
Voltage is is measured in what units and is aka?
Volts (v) and amplitude
83
Amplitude is aka?
voltage
84
Which values of Ohm's law can be programmed using the programmer?
voltage (v) and impedence (R)
85
Impedence is measured in what units and represented by which letter?
ohms and represented by (R)
86
What is the term meaning the force that moves the current?
voltage
87
What is the term for the opposition of current flow?
impedence or resistance
88
What are the types of insulation used in leads?
silicon and polyurethane
89
What is the normal acceptable lead impedence range:
1) low power lead
2) high power lead
1) 200 - 2000 Ohms
| 2) 20 - 200
90
What impedence trend or change is cause for concern and further investigation?
appx 30% increase or decrease in impedence from last interrogation or abrupt change
91
A decrease in impedence could signify?
a decrease in impedence could mean a break or leak in the insulation of a lead
92
An increase in impedence could siginify?
- an increase in impedence could mean:
1) a break or fracture in the lead conductor or wire
2) or lead is not seated properly in the header
93
What is lead crush?
- lead damage d/t crushing motion of clavicle and 2nd lead
94
What is a possible solution to lead crush?
reprogram bipolar setting to unipolar sensing and pace if inner conductor is intact
95
What is the term for the minimum stimulus needed to capture the cardiac tissue?
capture threshold
96
Capture threshold is a function of which values?
Amplitude and pulse width
97
What is pulse width?
the duration of the impulse generated, measured in milliseconds (ms)
98
What is the acceptable amplitude threshold safety margin?
2x the calculated amplitude threshold
99
What is the acceptable pulse width threshold safety margin?
3x the calculated pulse width threshold
100
What is shown on the strength duration curve?
- it shows the relationship between amplitude and pulse width
- plots min voltage needed to capture myocardium at various pulse widths
101
What graphical structure shows the relationship between amplitude and pulse width??
the strength duration curve
102
What are the types of therapy an ICD can deliver?
1) bradycardia pacing
2) cardioversion
3) defibrillation
4) antitachycardia pacing (ATP)
103
What component multiplies the voltage, which is then store in the capacitor?
the transformer
104
The transformer multiplies the voltage of an ICD up to what value?
up to 800 volts
105
Which component of an ICD stores the multiplied voltage from the transformer?
the capacitors
106
Which lead configuration in an ICD is known as true bipolar?
Right Vent tip (cathode), Right vent ring (anode)
107
Which lead configuration in an ICD is known as integrated bipolar?
Right vent tip (cathode), Right vent coil (anode)
108
What are the detection zones on an ICD?
V-fib, fast VT (FVT), V-tach
109
What do the following marker channels mean:
1) TS
2) TD
3) FS
4) FD
1) TS - sensed beat in VT detection zone
2) TD - VT detected or redetected
3) FS - sensed beat in VF detection zone
4) FD - VF detected or redetected
110
What do the following marker channels mean:
1) TP
2) CE
3) CD
1) TP - antitachycardia pacing
2) CE - charge end
3) CD - charge delivered
111
How many detection zones can be programmed into an ICD?
up to 3 detection zones can be programmed
112
What type of counter is used by an ICD to detect sustained VT?
consecutive counter
113
What type of counter is used by an ICD to detect sustained VF?
probabilistic counter
114
When is a combined count NID calculated and use in an ICD?
- used when rhythms go back and forth between the VT and VF zones
- looks back 8 beats
115
What are the types used when programming ATP?
1) Burst - stimuli delivered at equal intervals
| 2) RAMP - calculated % of detected rate with each sequence
116
What is the purpose of antitachycardia pacing?
- to overdrive pace tissue in excitable GAP area to interrupt the reentry circuit
- sequence should be faster than tachy rate
117
What are the steps to program ATP in an ICD?
1) chose therapy type (burst, RAMP)
2) select # of pulses per sequence
3) rate ATP is delivered
4) # of ATP sequences before moving to next therapy (shock)
118
What rhythms are ATP recommended for?
VT and FVT
119
What rhythms are cardioversion recommended for?
VT and FVT
120
What is important to remember regarding the administration of a cardioversion?
need to synch so shock can be delivered on R-wave to prevent shocking on the T-wave
121
What does the wavelet feature on the ICD do?
- stores NSR template for comparison
| - template should be evaluated at every visit
122
How does the wavelet feature determine if a rhythm is not NSR?
- at NID, compares the median interval of the last 12 to the S T Limit
- if the median interval slower than the SVT Limit, wavelet is applied
- algorithm them compares 8 QRS complexes to the stored template
- if 2 or more are < 70% match = not NSR
123
What is the Onset feature on the ICD do?
evaluates the acceleration of the rate to determine SVT vs VT
124
Placing a magnet on a pacemaker defaults the setting to what BPM?
- 85 bpm
| - 65 bpm if battery has entered RRT/ERI
125
Which nerve innervates the diaphragm?
the phrenic nerve
126
What is the normal cardiac conduction pathway?
- SA node
- AV node
- common bundle
- R and L bundle branches
- perkinje fibers
127
What is the normal value for cardiac output?
4-6 L/min
128
What is the normal value for the QRS complex?
60-100 ms
129
How do you convert from BPM to ms?
60k / BPM
130
How do you convert from ms to BPM?
60k / ms
131
What are the 2 main underlying mechanisms responsible for causing arrythmias?
1) abnormal automaticity - impulse formation issues
| 2) conduction issues - blocked or slowed impulse
132
What is the atrial rate seen during A-Flutter?
250-400 bpm
133
What is the atrial rate during A-fibrillation?
400 bpm or greater
134
What are the rates for the following:
1) SA node
2) AV node/junctional
3) perkinje/ventricular escape
1) 60-100 bpm
2) 40-60 bpm
3) 20-40 bpm
135
What is the rate seen during an Idioventricular rhythm?
```
ventricular = 20-40
atrial = 0
```
136
What is the rate seen during accelerated IVR
```
ventricular = 50-100
atrial = 0
```
137
What are the Class I PM indications for Sinus Node Dysfunction/ (are 4 answers)
- symptomatic bradycardia
- required medicine induced bradycardia
- symptomatic sinus pause (>3 secs)
- chronotropic incompetence
138
What are the Class IIa PM indications for Sinus Node Dysfunction?
- symptoms w/ HR <40 and syncope with no known cause
139
What are the Class I PM indications for 3 deg AV block? (6 answers)
- HR < 40 (symptoms or asymptomatic)
- asystole > 3 secs
- occurs even after an ablation
- occurred post-op
- block r/t neuromuscular disease
- intermittent 3rd block w/ BBB (wide QRS)
140
What are the Class I PM indications for for 2nd deg AV block?
- HR < 40 (symptoms or asymptomatic)
- asystole > 3 secs
- occurs even after an ablation
- occurred post-op
- block r/t neuromuscular disease
- 2nd deg type II block w/ BBB (wide QRS)
141
What are the Class IIa PM indications for 2nd deg AV block?
- asymptomatic w/ type II and narrow QRS
- intra or infra-HIS type I w/ narrow/wide QRS
- symptoms like pacemaker syndrome
142
What are the Class I PM indications for 1st deg AV block?
none
143
What are the Class IIa PM indications for 1st deg AV block?
- atrial systole occurs close to preceding vent systole
- hemodynamic issues/instability
- symptoms like pacemaker syndrome
- premature atrial contractions resulting in incomplete filling
- ventricular filling is compromised
- decreased CO
144
What is the term for syncope or presyncope r/t to an extreme reflex response to carotid sinus stimulation/
Hypersensitive Carotid Sinus Syndrome (HCSS)
145
What are the components of the neurocardiogenic reflex r/t to HCSS?
1) cardioinhibitory - decreased HR r/t increased parasympathetic tone
- increased PRI and/or advanced AV block
2) vasodepressor - loss of vascular tone = BP drop
146
What specific conditions are indications for PM placement?
- acquired AV block in adults
- chronic bifascicular and trifascicular block
- AV block associated with MI
- SND
- HCSS
- hypertrophic obstructive or idiopathic dilated cardiomyopathy
- heart transplants
- children, adolescents with congenital heart diseases
- prevention and termination of tachyarrhythmias
147
Pacing after valve surgery is recommended when the patient experiences __1__ occurring __2__ postop and lasting __3__ postop and will be unlikely to resolve within __4__.
1) complete AV block
2) < 24 hrs
3) >48 hrs
4) < 2 wks
148
What are the 3 pacemaker management strategies?
1) rate support
2) AV synchrony
3) manage comorbidities
149
NYHA Class I?
no symptoms
150
NYHA Class II?
symptoms with moderate activity
151
NYHA Class III?
symptoms with minimal activity
152
NYHA Class IV?
symptoms at rest
153
ACC/AHA Stage A?
high risk, no damage or symptoms
154
ACC/AHA Stage B?
structure damage, no symptoms
155
ACC/AHA Stage C?
structural damage, with current or previous symptoms
156
ACC/AHA Stage D?
end stage, needs specialized tx (refractory HR)
157
CRT stands for?
Cardiac Resynchronization Therapy
158
What is the most common type of PM battery?
lithium-iodine (2.8 volts)
159
What is the most common type of ICD battery?
silver-vanadium-oxide
160
Cathode has what type of charge?
negative - delivers impulse
161
Anode has what type of charge?
positive - receives impulse and completes the circuit
162
What does IPG stand for?
Implantable Pulse Generator
163
What is the term for the min rate a PM device will pace?
Lower Rate Interval (aka pacing interval)
164
Convert the Lower Rate of 60 BPM to ms?
60,000 / 60 BPM = 1000ms
165
What is the interval showing the max time before ventricular pacing occurs?
- Paced Atrial Interval (PAV)
- Sensed AV
- AV Delay
166
Question:
| If PAV = 200ms and the LRI is 60 BPM, what is the VA interval going to be?
- LRI = PAV + VA inteval
- 60 BPM or 1000ms = 200ms + VA interval
- VA interval = 800ms
167
What is the Chronaxie?
point on strength duration curve where amplitude is 2x the value of the rheobase
168
What is the Rheobase?
the lowest point of capture on strength duration curve
169
What is the recommended R-wave amplitude at implant?
≥ 5.0 mV (the bigger the better)
170
What is the recommended P-wave amplitude at implant?
≥ 1.5 mV (the bigger the better)
171
What is the recommended sensitivity safety margin?
at least half of the sensing value
172
What are the 3 types of threshold tests?
1) amplitude threshold test
2) pulsewidth threshold test
3) Strength duration curve
173
How do conduct an Amplitude threshold test?
- pulse width held constant (0.4ms)
- look at ACM threshold value
Set:
- V -> VVI rate 10-15 higher
- A -> DDD rate 10-15 higher and extend AVD to 350m
- don’t do atrial if pt is in afib
- note 1st loss of capture
174
How do conduct a pulsewidth threshold test?
- test => threshold => pulse width
- set voltage (held constant)
- set pulse width
- pulse width decreases automatically
- note 1st loss of capture
- threshold = value prior to loss of capture
- safety margin = 3x pulse width
175
What part of the strength duration curve denotes the optimal settings for battery longevity?
the knee
176
During the R-wave amplitude test at implant, what is the required R-Wave amplitude value to ensure all R-waves are detected?
> 5 mV
177
Which type of insulation allows for a smaller lead diameter and lower friction coefficient?
polyurethane
178
What are the indications for a Pacemaker?
- sinus node dysfunction (brady, sinus pause)
- conduction block
- syncope
179
Why would patients taking digoxin require a pacemaker?
digoxin slows AV conduction and a ventricular PM may be necessary if AV conduction is slowed to much
180
CRT is considered in what stage of the HF treatment continuum ladder?
Stage C, if BBB is present
181
What are the classes of A-Fib?
- paroxysmal
- persistent
- permanent
182
Definition of paroxysmal A-Fib?
≥ 2 A-fib episodes that self-terminate within 7 days
183
Definition of persistent A-Fib?
recurrent episodes lasting > 7 days
184
Definition of permant A-Fib?
A-Fib lasting > 1yr
185
Which rhythm is often associated or seen in patients with bradycardia?
A-fib
186
What are the treatment options for A-Fib?
- meds (BB, CCB, antiarrhythmics)
- cardioversion
- ablation
- pacemaker
187
AHA suggests that what EF value is an indication of HF?
< 40%
188
What are the different types of lead fixation options?
- active
- passive
- epicardial
189
Large pacing spikes and extra cardiac stimulation are seen in which type of pacing system?
these are pacing characteristics of a unipolar system
190
In a unipolar system, what components act as the cathode and anode?
- cathode = conductor coil
| - anode = can or IPG
191
A unipolar lead system is susceptible to over or undersensing?
oversensing d/t distance between the cathode and anode
192
In a bipolar system, what components act as the cathode and anode?
- cathode = tip
| - anode = ring or coil
193
What happens to the current flow as the voltage increases?
current flow will increase by the same amount
194
What happens to the current flow as the impedence increases?
current flow will decrease
195
An increase in impedance values is indicative of what?
possible lead fracture or conductor break
196
An decrease in impedance values is indicative of what?
possible break in the insulation
197
```
Question:
If voltage (v) = 5v; impedance (R) = 500 ohms
Find current (I)?
```
(5v / 500 ohms) x 1000 = 10 mA
198
```
Question:
If voltage (v) = 10v ; current (I) = 0.8 mA
Find impedance (R)?
```
(10v / 0.8 mA) x 1000 = 1250 ohms
199
Once the battery has reach RRT/ERI, the device switches to what mode and rate and for how long?
VOO at 65 BPM for up to 3 months
200
What does PBL-STOP stand for?
- Presenting rhythm, rate and % paced
- Battery status
- Lead impedance
- Sensing thresholds
- Threshold (amplitude, pulse width, SD curve)
- Observations
- Print
201
When does the Lower Rate Interval start?
- starts with the atrial event
| - is the A-A interval
202
Pacing capture is a function of?
amplitude and pulse width
203
What is the definition of cross-talk?
when the lead in one chamber senses the paced event from another, resulting in inappropriate inhibition of needed pacing
204
What feature is designed to prevent pacing inhibition d/t cross-talk?
the ventricular safety period
205
What is the purpose of the ventricular safety period (VSP)?
- to prevent pacing inhibition d/t cross-talk
| - prevents pacing on t-wave
206
What are methods of managing cross-talk?
1) reduce atrial output
2) decrease ventricular sensitivity
3) program to bipolar (if possible)
4) increase PAVB period (only as last resort)
207
How long is the ventricular safety period (VSP)?
110 ms interval that starts after atrial paced event
208
Why is the Paced AV (PAV) interval longer (appx 30ms) than the Sensed AV (SAV) interval?
- the PAV interval is longer then the SAV to account for the slower cell to cell propagation pathway
- pacing site may no be near the conduction p-way so time is needed to allow signal to reach the p-way
209
What are the methods for preventing or correcting Pacemaker Mediated Tachycardia (PMT)?
1) PVC response program
2) PMT Intervention
3) auto-PVARP
210
Why would PMT Intervention be turned on?
- atrial over/undersensing
| - atrial noncapture
211
What does the PVC response program do?
- extends the Post Ventricular-Atrial Refractory Period (PVARP) to 400ms following a PVC
212
How does the Pacemaker Mediated Tachycardia intervention work?
- extends the Post Ventricular-Atrial Refractory Period (PVARP) to 400ms after PMT detection
213
How long is the PVARP extended in the treatment in response to a PVC or detected PMT?
400ms
214
What is the upper tracking rate or upper tracking interval (UTI)?
- is the fasted rate the pacemaker will pace the ventricles
| - starts after ventricular sensed/paced event
215
What are the criteria for pacemaker Wenckebach behavior?
- UTI < AR < TARP
- Upper tracking rate < atrial rate
AND
- atrial rate < Total Atrial Refractory Period (TARP)
216
What are the criteria for pacemaker mediated 2:1 block?
Total Atrial Refractory Period (TARP) < atrial rate
217
What intervals make up the Total Atrial Refractory Period (TARP)?
SAV or PAV + PVARP = TARP
218
Question:
UTR = 120 BPM; SAV = 200ms; PVARP = 350ms
What will be seen, 1:1 tracking, PM Wenckebach, or 2:1 block?
1) UTI = 60K / 120 bpm = 500ms
2) TARP = SAV (200ms) + PVARP (350ms) = 550ms
3) TARP (550ms) > UTI (500ms) = 2:1 block
219
Triple Chamber pacemakers are also known as?
- Bi-Ventricular
| - Cardiac Resynchronization Therapy (CRT-P)
220
Which type of pacemaker is used for Cardiac Resynchronization Therapy (CRT-P)?
triple chamber or Bi-Ventricular
221
When is a magnet used on a cardiac device?
- check battery status
- presence of EMI (surgery)
- device troubleshooting
222
Applying a magnet temporarily changes the mode of the pacemaker to what?
- asynchronous pacing (DOO, AOO, VOO)
223
When does lead dislodgement usually occur?
within 6 weeks of implant, will see increase in lead impredances
224
What is the normal impedance value for an ICD lead?
20-200 ohms
225
What are acceptable chronic P-wave amplitude values?
≥ 0.1 mV
226
What are acceptable chronic R-wave amplitude values?
≥ 3.0 mV
