PDF focus Flashcards
(199 cards)
1
Q
What is the pathway through the heart?
A
SA node
Internodal tracts
AV node
bundle of His
Bundle Branches
Purkinje fibers
2
Q
What are the three internodal tracts?
A
1.Anterior (Left) Bachmann bundle
- Middle - Wenckebach
- Posterior - Thorel
3
Q
What are the three conduction velocities?
A
- SA + AV - 0.02 (Slow conduction)
- HIS, Branches, Purkinjie - 1.0 (Fast)
- Myocardium - 0.1 (Intermediate)
4
Q
What is conduction velocity a function of?
A
- RMP
- Amplitude of action potential
- Rate of change in phase 0
5
Q
What five things affect conduction velocity?
A
ANS tone
Hyperkalemia
Ischemia
Acidosis
Antiarrhythmic drugs
6
Q
What are the accessory pathways?
A
Bypasses normal conduction pathway
7
Q
What is the James fiber pathway?
A
Atrium to the AV node
8
Q
What is the atrio-Hisian fiber?
A
Atrium to HIS bundle
9
Q
What is Kents bundle?
A
Atrium to ventricle
10
Q
What is Mahaims bundle?
A
AV node to ventricle
11
Q
What happens during phase 0 of ventricular action potential? Ion Movement?
A
Depolarization (QRS)
Na+ rushes into cell - making it more positive
12
Q
What happens during phase 1 of ventricular action potential? Ion Movement?
A
Initial repolarization (QRS)
Cl- moves in and K+ moves out
(downward deflection since it is becoming more negative inside the cell)
13
Q
What happens during phase 2 of ventricular action potential? Ion Movement?
A
Plateau phase (QT interval)
Ca + in and K+ out
Balance each other out so it is a straight line
14
Q
What happens during phase 03 of ventricular action potential? Ion Movement?
A
Final repolarization (T wave)
K+ out
15
Q
What happens during phase 4 of ventricular action potential? Ion Movement?
A
Resting phase (T wave to QRS)
Na+ out
16
Q
When is the absolute refractory period?
A
Between phase 0/1 and ends in the middle of phase 3
NOTHING can stimulate the cell
17
Q
When is the relative refractory period?
A
Middle of phase 3
VERY STRONG stimulus is required
18
Q
What can be seen with PR depression?
A
Pericarditis
19
Q
What condition is associated with a U wave?
A
Hypokalemia
20
Q
Peaked T waves can be caused by?
A
MI, Hyperkalemia, Intracranial bleed
21
Q
ST elevation or depression greater than____mm, can be an MI?
A
1mm
22
Q
Hypercalcemia and hypocalcemia what is seen on EKG?
A
Hyper - Shorted QT
Hypo - Long QT
23
Q
Which limb leads monitor the inferior wall of the heart?
A
II, III, aVF
24
Q
Which limb leads monitor the later side of the heart?
A
I, aVL, V5, V6
25
Which limb leads monitor the LAD septum?
V1, V2
26
Which limb leads monitor the LAD anterior?
V3, V4
27
What is the normal axis degree numbers?
Between -30 and +90
28
If the axis is more negative, that means what type of deviation?
Left
29
If the axis is more positive, that means what type of deviation?
Right
30
What two things can cause a Sinus arrythmia?
-Breathing
--Inhale faster HR
--Exhale slower HR
-Bainbridge reflex
31
What is the first line of treatment for bradycardia? Dosage?
Atropine but if less than 0.5 can cause paradoxical bradycardia through the muscarinic receptors
32
What should severely symptomatic bradycardic patients receive?
Pacing
33
How does glucagon work?
Increasing cAMP
Helpful in CCB and BB overdose
34
How does sinus tachycardia affect the heart?
Increases O2 consumption while decreasing supply
35
What must be performed with new AFIB or Aflutter older than 48 hours?
TEE
36
Should you cancel surgery with new AFIB or Aflutter?
Yes
37
What is the most common postoperative tachyarrhythmias?
AFIB
38
Is afib or aflutter organized?
Aflutter with a rate of 250-300
Not all signals get past the AV node
39
Treatment for Aflutter?
Cardioversion at 50 J
40
Where do PVC originate from? What causes them?
AV node
Many things -
41
When and how should PVCs be treated?
When they are frequent (>6 a minute)
-Reverse the underlying cause
-Treat with lidocaine 1mg/kg
42
What is Brugada syndrome
Sodium channel issue
Causes nocturnal death in Asian men
Can be seen on V1-V3 and need ICD
43
What heart blocks affect the AV node? treatment?
Type 1
Type 2 I (longer longer, drop)
Monitor
44
What heart block affects the bundle branches?
Type 2 II (random p drops)
45
What heart block has degeneration of the atrial conduction system? (Lenegre's)
Type 3
Need to pace or isoproterenol
46
How does adenosine work? Half life?
Slows conduction through the AV node by stimulating the adenosine receptor and inhibits K channels
Hyperpolarizes the membrane
5 second half life
47
When is adenosine helpful? Not?
What can it cause?
Good for SVT and WPW
Bad for afib, aflutter, vtach
Bronchospasm in asthmatic patients
48
Dosage for adenosine for peripheral and central?
P -6mg then 12
C-3mg then 6
49
What is the most common cause of tachyarrhythmias?
Reentry pathways
(backwards movement of electrical impulse)
50
How to stop a reentry pathway?
Break the circuit
1. Slow conduction velocity
2. Increase refractory period
51
Examples of a reentry pathway where velocity is too slow?
Ischemia
Hyperkalemia
52
Examples of a reentry pathway where refractory period is shorter?
Epi
Electric shock
53
Examples of a reentry pathway where it occurs over a long distance?
Left atrial dilation to mitral stenosis
54
What is WPW?
Most common pre-excitement syndrome
Direct communication between atria and ventricle
Seen with Delta wave
55
What are two ways WPW can be classified ? Which is most common? What is more dangerous?
Orthodromic and antidromic
Common-Orthodromic
Dangerous - Antidromic
56
Which AVRNT has a narrow QRS and a wide QRS?
Ortho- Narrow
Anti- Wide
57
What are two safe options for both AVRNT?
Amio and cardioversion
58
What are the only three things for antidromic treatment?
Amio
Cardioversion
-Procainamide
59
What is the treatment for WPW combined with afib?
Procainamide
60
Definitive treatment for WPW? What must be monitored?
Ablation
Esophageal temp
61
Treatment for torsades?
Mag
Pacing
Avoid SNS stimulation
62
What does DDD mean on a pacemaker?
Dual Paced
Dual Sensed
Dual triggered and inhibited
63
What does AOO mean on a paceaker?
Atrial paced
No sense
No response to native cardiac activity
64
What does VVI mean on a pacemaker?
Ventricular paced
Ventricular sensed
I tells pacemaker not to fire if electrical activity is seen
65
What 3 things cause a pacemaker to fail?
1. Pulse generator failure
2. Lead failure
3. Failure to capture
66
What can impair a pacemaker?
Electrocautery and radiofrequency ablation
Bipolar is much better
67
MRI with a pacemaker?
Contradicted
68
What is the most important thing to know about pacemakers?
The underlying rhythm so you know how to treat
69
What happens when a magnet is placed on a pacemaker?
Goes to asynchronous mode
70
What happens when a magnet is placed on a ICD?
Suspends the shock
71
What happens when a magnet is placed on a pacemaker and ICD?
Suspends ICD but not the pacemaker
72
What is seen after a PAC?
Non compensatory pause
73
In Aflutter, does every atrial depolarization have a contraction?
Yes
74
What two syndromes are associated with prolonged QT?
Timothy and Romano Ward
75
What does cerebral oximetry monitor?
Global oxygenation of VENOUS blood.
75% of blood in the brain is venous
76
What percentage change suggests a reduction in cerebral oxygenation? What can contaminate the signal
>25%
Scalp hypoxia can throw off numbers
77
How do brain waves change during anesthesia?
Induction and light anesthesia increases beta waves
78
What produces burst suppression?
Deep anesthesia
79
At what MAC level can cause complete suppression of Isoelectricity?
1.5-2.0
80
Which anesthetic gas can produce beta waves?
N2O
81
Which anesthetic gas can produce seizures?
Sevo
82
Which drug can cause myoclonus but not associated with epilepsy
Etomidate
83
Which drug can falsely elevate EEG?
Ketamine
84
When else can burst suppression occur?
Hypothermia, CPB
85
What is unilateral burst suppression suggestive of?
Cerebral ischemia
86
What are the order of brain waves?
Beta
Alpha
Theta
Delta
Burst suppression
Isoelectricity
87
Which brain wave is associated with GA, hypothermia, CPB, and ischemia?
Burst suppression
88
Which brain wave is associated with GA and children sleep?
Theta
89
Which brain wave is associated with GA, deep sleep, and brain injury?
Delta
90
Which brain wave is associated with awake mental stimulation and light anesthesia?
Beta
91
Which brain wave is associated with awake but restful sleep with eyes closed?
Alpha
92
When happens to brain waves as the anesthesia becomes deeper?
Lower frequency and higher amplitude
93
What two things can interfere with BIS?
Nitrous and Ketamine
94
What is the time delay of BIS?
20 seconds
95
When also is BIS less accurate?
Children, hypothermia, increased muscle tone, encephalopathy
96
Which law does electricity follow ?
Ohm's law
Voltage - driving pressure
Current - Flow
Impedance - Resistance
97
What is the maximum allowable current leak in the OR? When does Vfib occur?
10 uA
100 uA
98
Is the OR power supply grounded?
NO
99
Is the equipment in the OR grounded?
YES
100
What is the Line isolation monitor?
It tells you when the OR BECOMES GROUNDED
101
Does the Line isolation monitor protect you?
No it is just alarm when a leak of 2-5 mA is detected
102
What is a grounding pad?
Provides an exit point for electricity on the patient.
IT DOES NOT GROUND THE PATIENT
103
What do you do if there is exhaustion of the CO2 absorbent?
Increases FGF to 5-8
TIVA
Do not increase the MV because it will not fix the issue
104
If increasing FGF does not fix the problem, what is likely the issue?
Incompetent unidirectional valve
105
What components are not present in a Mapleson circuit?
Unidirectional valves
CO2 absorber
106
Advantages of a Mapleson?
Less airway resistance (good for peds)
Convenient
Easily scavenged
Bain circuit prevents heat loss
107
What is the pethick test?
A test for the integrity if the inner tubing on the Bain circuit
108
Which Mapleson is best for spontaneous ? Worst?
Best - A (spontAneous)
Worst - B
109
Which Mapleson is best for cmv ? Worst?
Best- D (controlleD)
Worst - A
110
How much FGF is required when using a Mapleson?
2.5 x minute ventilation
Mapleson A needs 20L/min
111
What is the Bain system good for?
Modified Mapleson D
Has thin inner tubing and the gas is warmed through the corrugated tubing around it
112
How is the Pethick test performed?
-Occlude the elbow
-Close APL
-Flush with O2
-Remove occlusion while flushing
****if the bag deflates it is okay to use
***if the bag stays inflated, NOT okay
113
Which Mapleson circuits are most likely to be seen today?
D,E,F
114
How is compiance measured?
Change in Volume / Change in Pressure
115
What is compliance influenced by?
Muscle tone
Degree of lung inflation
Alveolar surface tension
Interstitial lung water
Pulmonary fibrosis
116
What is dynamic compliance?
Movement of lungs
117
What is static compliance ?
Lungs are not moving
118
When is plateau pressure measured?
-During static (no airflow)
-Barotrauma when pressure exceeds 35
119
What is a normal Alpha angle? What conditions cause in increase?
100-110 degrees
**obstruction
COPD, Kink, bronchospasm
120
What may be the cause of increased beta angle?
Falty unidirectional valve
121
What is the PaO2 if the SpO2 reads 90?
60 - 30 point difference
122
What site is the fastest response for a SpO2? Slowest?
Fastest - Head
Middle - Finger
Slowest-Toe
123
Inline(Main stream) end tidal is useful for ?
Fast response
Increases Dead space
Doesn't require a pump or trap
124
Side stream (diverting) is useful when?
Outside the airway
Requires pump/water trap
Slower response time
125
What two wavelengths does a pulse emit?
940 - near infrared(arterial,oxy)
660- Red light (Venous,deoxy)
126
What shifts to L on the oxyhemoglobin curve?
Decreased everything and alkalosis
127
What shifts to R on the oxyhemoglobin curve?
Increased everything and acidosis
128
What does the pulse ox monitor ? (3 things)
What does it not?
1. Hgb saturation
2. HR
3. Fluid responsiveness
**Does not measure anemia or ventilation
129
What is methemoglobin?
Equal light at 660 and 940
Pulse ox will read 85%
Could be higher or lower
130
What is carboxyhemoglobin?
Absorbs at 660
So it overestimates SpO2
May say 99% when it really is 80%
131
Which factors do not affect pulse ox?
Hgb S
Hgb F
Jaundice
Fluorescein
Polycythemia
Acrylic nails
132
How is all gas analyzed on all modern machines?
Infrared spectrophotometry
O2 is by galvanic cell or paramagnetic
133
What is the ideal length of the bladder on a BP cuff?
80% circumference
134
What is the ideal width of the bladder on a BP cuff?
40%
135
Where is the narrowest PP?
At the artic root
SBP is lowest and DBP is highest
136
Where is the widest PPV?
Foot
137
If the BP cuff is above the heart will the reading by falsely high or low?
Falsely low
138
How much does BP change for every 10cm? every inch?
10cm = 7.4mmhg
1inch= 2mmhg
139
How many oscillations are appropriate for an optimally damped Art line?
1
140
How many oscillations are seen for an under damped Art line?
many bounces
SBP is overestimated and DBP is under
141
How many oscillations are seen for a over damped Art line?
None
SBP is underestimated, DBP is over
142
Examples of an overdamped Art line?
Air bubble
Clot
No pressure
143
Examples of under dampened Art Line?
Stiff tubing
Catheter whip
144
Is the MAP accurate with an over or under dampened art line?
Yes
145
Distance from insertion site for
Subclavian
R IJ
L IJ
Femoral
Basilic
Subclavian - 10 cm
R IJ - 15 cm
Left IJ - 20 cm
Femoral - 40 cm
Basilic - 45
146
Distance through heart?
RA
RV
PA
PAOP
RA 0-10cm
RV 10-15cm
PA 15-30cm
PAOP 25-25cm
147
Where should a CVP catheter reside? PA catheter?
CVP - Junction of the vena cava and RA (**NOT INSIDE)
RA - in the PA
148
When does infection risk increase for central lines?
After three days
149
What is at risk for obtaining an L IJ?
Thoracic duct puncture resulting in chylothorax
150
Should you advance a PA if the patient has a LBBB?
NO, advancing may result in a RBBB which leads to complete heart block
151
Classic sign of a pulmonary artery rupture?
Hemoptysis
152
What three things increases risk of a PA rupture?
-Hypothermia
-Anticoagulation
-Advanced age
153
What is the a wave on a CVP?
Right atrial contraction
(Just after the P wave on an EKG)
154
What is the C wave on a CVP?
Right ventricle contraction (the bulging of the tricuspid into the TA)
Just after the QRS on an EKG
155
What is the X descent on a CVP?
RA relaxation
ST segment on EKG
156
What is the V wave on the CVP?
Passive RA filling
Just after the T wave begins on a EKG
157
What is the y descent on an CVP?
RA empties through a open tricuspid valve
After the T wave ends
158
What should Right atrial pressure equal?
Left ventricle end diastolic pressure
159
What might it mean if the A wave is loss on a CVP?
Atrial contraction is lost
Afib
V pacing
160
What might a large A wave mean?
High pressure or resistance
Lung disease
Diastolic dysfunction
Tricuspid stenosis
MI
AV issues
161
What might a large V wave signal?
-Tricuspid regurg
-Acute Increase in intravascular volume
-RV papillary ischemia
162
Normal RA pressure?
1-10
163
Normal Right ventricle pressure?
15-30
and
0-8
*Diastolic is equal to cvp
164
Normal PA pressure? Waveform?
25/10
Waveform looks just like A line
165
Normal PAOP? Waveform?
5-15
Just like a CVP waveform
166
What zone should the PAC be in?
Zone III since there is a continuous column of blood
Zone III is the dependent region
Pa>Pv>PA
167
How can you tell the PA tip is NOT in west zone III?
1. Nonphasic tracing
2. PAOP > PA end diastolic rescuer
3. Cannot aspirate blood from the distal port
168
Conditions where PAOP underestimates LVEDV?
Aortic regurg
169
How is thermodilution done?
5% dextrose and NS are injected through the proximal port.
If the fluid rapidly travels then the CO is high and if it takes longer then the CO is low
170
What are the 4 variables to Mixed venous saturation?
Q=CO
VO2=O2 consumption
Hgb
SaO2
171
Why is a PA required to measure SvO2?
Need to measure all blood returning to the heart
SVC
IVC
Coronary Sinus
172
Distance for R subclavian, R IJ, L IJ?
Distance for PA through heart?
R sub - 10cm
R IJ - 15cm
L IJ - 20
RA - 10
RV - 15
PA - 20
Wedge - 30
173
When should CVP be measured?
End expiration
174
What is seen on the PA waveform when the PA enters the PA?
Diacrotic notch
Increased in diastolic BP
175
When does PAOP overestimate LVEDP?
PEEP and diastolic dysfunction
176
When does PAOP underestimate LVEDP?
Aortic insufficiency
177
How does a high injectate volume effect CO? Low volume?
High volume = underestimates
Low volume = overestimates
178
Can you accurately measure CO with a R to L shunt?
No
179
How does warm injectate and a partially wedged catheter effect CO?
over estimates
180
When should thermodilution be used over continuous CO? Why?
Unstable patients because continuous monitoring has a delay
180
How does hypothermia effect SVO2?
Increases SvO2
181
How does fever effect SVO2?
Decreases
182
How does cyanide toxicity effect SVO2?
Increases
183
How does anemia effect SVO2?
Decrease
184
How does RBC infusion effect SVO2?
Increases
185
How does shivering and pain effect SVO2?
Decreases
186
How does hypoxemia effect SVO2?
Decreases
187
How does thyroid storm effect SVO2?
Decreases
188
How does increased CO effect SVO2?
Increases
189
What is a normal SVO2?
65-75%
190
When assessing fluid responsiveness, how much should stroke volume increase when a 250mL bolus is given ?
10%
191
How does increased LV filling effect stroke volume? Decreased filling?
Increased filling = larger stroke volume (Starling mechanism)
Decreased filling = Smaller stroke volume
192
Howd does a positive pressure breath effect LV filling?
Augments LV filling, Decreases RV filling
193
Should you use an esophageal doppler with esophageal disease? Will it effect the values?
Do not use but won't effect the value if used
194
What varibles will affect esophageal doppler?
Any issues with the aorta, pregnancy, CPB
195
An esophageal doppler, when medicine is given to increase the width of the triangle?
Fluid, by giving fluid the it will become wider
196
An esophageal doppler, when medicine is given to increase the height of the triangle?
Vasodilator
197
An esophageal doppler, when medicine is given to increase the height and decrease the width of the triangle?
Inotrope
198
What conditions increased pulmonary resistance?
kinked tube
ET cuff herniation
Foreign body
Compression of airway
bronchospasm
bronchial secretions
