CV monitoring - Exam 1 Flashcards
1
Q
Impulses traveling toward the lead “eyeball” are ________.
A
positive
2
Q
Impulses traveling away from the lead “eyeball” are ________.
A
negative
3
Q
How many limb leads do we have?
A
4
* commonly only use 3
4
Q
Augmented Limb Leads
aVR
pos:
neg:
A
- pos: right arm
- neg: b/w LA & RL
5
Q
Augmented limb leads
aVL
pos:
neg:
A
- pos: LA
- neg: RA & LL
6
Q
Augmented Limb leads
aVF
pos:
neg:
A
- pos: LL
- neg: RA & LA
7
Q
Precordial Leads
V1 placement & view of heart:
A
- placement: 4th ICS, R sternum
- view: septal
should be negative
8
Q
Precordial Leads
V2 placement and view of heart:
A
- placement: 4th ICS, L sternum
- view: septal
should be negative
9
Q
Precordial Leads
V3 placement and view of heart:
A
- placement: b/w V4 and V2
- view: anterior
should be even/positive
10
Q
Precordial Leads
V4 placement & view of the heart:
A
- placement: 5th ICS, L sternum @ mid clavicular line
- view: anterior
should be the most positive lead
11
Q
Precordial Leads
V5 placement & view of the heart
A
- placement: 5th ICS, anterior axillary line
- view: lateral
should be positive
12
Q
Precordial leads
V6 placement & view of the heart:
A
- placement: 5th ICS mid axillary line
- view: lateral
should be positive
13
Q
12-lead EKG
What leads give an inferior view of the heart?
A
II, III, aVF
14
Q
12-lead EKG
What views give a lateral view of the heart?
A
V5 & V6
I & avL = high lateral
15
Q
12-lead EKG
What leads give an anterior view of the heart?
A
V3 & V4
16
Q
12-lead EKG
What views give a septal view of the heart?
A
V1 & V2
17
Q
12-lead EKG
what does a 12 lead help identify? (4 things)
A
- rhythm
- conduction delays
- infection
- damage
18
Q
12-lead EKG
What EKG change is indicative of heart damage/problem?
A
> 2mm change in contiguous leads!
19
Q
12-lead EKG
What is the turn signal rule?
A
helps identify BBB
1. find the J point in V1
2. look back into the complex (to the left)
3. positive deflection = RBBB
4. negative deflection = LBBB
5. QRS must be >0.12s
20
Q
Axis Deviation
What leads do we look @ to determine axis deviations?
A
I, II, III
21
Q
Axis Deviations
What is a normal axis deviation?
A
0-90 degrees
* I, II, III upright (positive)
22
Q
Axis Deviation
What is a physiologic L axis deviation?
A
- 0 - (-40) degrees
- I: positive
- II: positive or =
- III: negative
Cause: hypertrophy (obese and athletic)
23
Q
Axis Deviation
What is a pathological L Axis deviation?
A
- (-40) to (-90) degrees
- I: pos
- II: negative
- III: neg
- anterior hemiblock
24
Q
Axis Deviation
What is a R axis deviation?
A
- 90-180 degrees
- always pathologic in adults
- I: neg
- II: pos/=/neg
- III: pos
- posterior hemiblock
25
# Axis Deviations
What is an extreme R axis deviation?
* V-tach
* I: neg
* II: neg
* III: neg
* **ventricular in origin**
26
Axis Deviation Chart
27
# 12-lead EKG
Diagnosis for R atrial hypertrophy
* initial component of "P" larger in V1
* height > 2.5mm in any limb lead
28
# 12-lead EKG
Diagnosis for L atrial hypertrophy
* terminal portion of dipahsic P larger in V1
* occurs w/ mitral stenosis, systemic HTN
29
# 12-lead EKG
Diagnosis for R Ventricular hypertrophy
* more depolarization toward V1
* QRS in V1 positive, R waves get smaller
* concentric hypertrophy - more depolarization toward V1
30
# 12-lead EKG
Diagnosis/EKG for LV hypertrophy
* large S wave in V1
* larger R wave in V5
* depth of V1 and height of V5 = 35mm
31
# 12-lead EKG
Diagnosis/EKG in myocardial ischemia
* reduced supply of O2 from coronary arteries
* inverted, symmetrical T wave
32
# 12-lead EKG
myocardial injury
* acute MI
33
# 12-lead EKG
Myocardial Infarct (transmural)
* Q indicated necrosis, and makes diagnosis of old infarct
* >1mm wide or 1/3 QRS tall & 2 related leads
34
# Pacemakers
What are PM the treatment of choice for?
* disturbances in cardiac impulse conduction (brady or tachy)
* causes: excessive BB (elderly), SSS
* **also used after cardiac surgery s/a valve replacement/CABG**
35
What are the 3 types of PM?
* transthoracic (permanent)
* transcutaneous (pads)
* transvenous (similar to PA cath)
36
# Pacemakers
Ex: pt has high degree block not responding to meds (atropine)
What do we do??
* transcutaneous pacer
* set HR 60-80
* slowly increase voltage until electrical capture seen
* monitor for mechanical capture (heart responding to impulse)
37
# Pacemakers
What are the 2 main parts of the pacemaker?
1. pulse generator: provides electricity through the leads (zoll, external device, implantable device)
2. electrode leads
38
# Pacemaker definitions
Generator:
* energy source & electrical circuits
* provides current to go through leads
39
# Pacemaker definitions
Lead:
* insulated wire from generator to electrode
* **insulated**: wire comes into contact w/ other things before it gets to place it is supposed to be
40
# Pacemaker definitions
Electrode:
* exposed metal end in contact w/ endocardium or epicardium (epicardial leads)
* where energy is exposed to the heart
41
# Pacemaker definitions
Unipolar electrodes
* neg. electrode in chamber
* pos. electrode (grounding)
* more sensitive to electromagnetic interference (EMI)
* requires more energy
42
# Pacemaker definitions
Bipolar electrodes:
* both electrodes in chamber being paced (going from point A to point B)
* more common & **uses less energy**
43
# Pacemaker definitions
Multipolar leads
* multiple electrodes within 1 lead but multiple chambers
* ex: biatrial/biventricular electrodes
* electrode transverses the septum
44
# Pacemaker Codes
What is I?
0:
A:
V:
D:
**chamber that is paced**
* 0: none
* A: atrial
* V: ventricular
* D: dual (A+V)
*0 = no pacer, not programmed/active*
45
# Pacemaker Codes
What is II?
0:
A:
V:
D:
**chamber that is sensed**: on-demand device (watches what HR is doing and that determines the response)
0: none
A: atrial
V: ventricular
D: dual (A+V)
46
# Pacemaker Codes
What is III?
0:
T:
I:
D:
**response to sensing**
* 0: does nothing different when it senses
* T: triggered - if pt falls outside of set parameters (bradycardic) the PM responds to the low HR
* I: inhibit - if PM senses traditional/spontaneous depolarization it will not activate
* D: dual - does both **most common response to sensing**
47
# Pacemaker Codes
What is IV?
0:
R:
**rate modulation** -- artifact setting
* may mean it is able to adapt
* not common - response to overdrive pacing usually
* 0: none
* R: rate modulation
48
# Pacemaker Codes
What is V?
O:
A:
V:
D:
**multisite pacing**
* biatrial/biventricular or both atrial and ventricular
* O: none
* A: atrium
* V: ventricle
* D: dual (A+V)
49
# Pacemaker Codes
What is inhibition?
* intrinsic activity perceived - chamber is NOT PACED
50
# Pacemaker Codes
What is Triggered?
What is it used for?
* Pacemaker discharges **if intrinsic activity is sensed**
* used for testing devices - make pt bradycardic/tachycardic to prove good capture
51
# Pacemaker Codes
What is Rate Modulation?
* **artifact setting**
* tailored for pt
* vibration
* motion
* Vm
* R Ventricular pressure
52
# Pacemaker Codes
What pt population do we see the use of biventricular pacers in?
* horrible cardiomyopathies
53
# PM- EKG examples
Traditional QRS
* both atria/ventricles working
54
# PM Codes - EKG examples
Normal atrial impulse & Ventricles not working
* pacer spike then QRS complex
55
# PM - EKG examples
AV pacer
* atrial spike followed by impulse
* ventricular spike followed by depolarization
56
# Peri-op Care of PM:
What 2 main things do we need to consider w/ PMs?
1. how can we safely manage the pt?
2. do we need to change anything?
57
# Peri-op care of PM
Is interrogation needed?
* pre-op: not routinely
* post-op: maybe to ensure it was not influenced by electrocautery
58
# Peri-op Care of PM
What precautions shall be taken w/ the grounding pad for electrocautery?
* do not put pad near PM
* avoid use of monopolar cautery near device
59
# Peri-op care of PM
What happens when you put a magnet on the device?
* turns it into a non-demand mode
* goes to regular settings (HR 60-80)
* some newer devices don't do this!
60
# Bi Ventricular pacing
Where are the leads? (3 chamber)
* lead in RA
* Lead in both ventricles (trans-septal)
61
What is the goal of bi-ventricular pacing?
* increase synchronization b/w ventricles in pts w/ cardiomyopathy = improved CO
**improves RV-LV activation time**
**increases EF %**
62
What are the 3 main requirements for Bi-V pacing?
1. moderate/severe HF w/ EF (30-35% **now 10-20%**)
2. intraventricular conduction delays - resynchronization needed
3. Hx of cardiomyopathy induced cardiac arrest (young athletes w/ OOH cardiac arrest)
63
What is the typical anesthesia plan for PM placement?
* GETA - always default (pts don't tolerate)
* sedation w/ local
64
What are blocks we can do for pacemaker placement?
* periclavicular block
* cervical plexus block
* surgeon - local @ site
65
What is the procedure for PM placement?
1. incision below clavicle
2. create pouch where generator will live
3. put electrodes into subclavian and run them down to the heart
66
# Magnets and PM
What does placing a magnet on a PM do?
* puts it into an asynchronous pacing mode w/ no rate modulation
* takes it to default rate
* **devices have changed**
67
# Magnets and PM
If we put a magnet on a PM what do we need to do post-operatively?
* have it interrogated
68
What is the peri-op care of a AICD/BiV?
* optimize pt condition
* turn filter OFF on cardiac monitor
* bipolar cautery
* back-up pacing ability available
* interrogation post-op
69
What does an implantable cardioverter-defibrillator do?
* can terminate VF or VT
* measures R-R intervals & if it's too short = shock delivered
* **can inappropriately shock SVT**
70
# Pacemakers
What can cause malfunctioning of an AICD?
* old batteries
* cracked wires
* pt moves wrong way, HR goes too high
* irregular rhythms - can't measure R-R
71
Where is CVP measured?
What is the measurement dependent on?
What is the measurement used to assess?
* junction of vena cava and right atrium
* d/o blood volume and vascular tone
* assessment of blood vol. and R heart function
72
Reasons CVP will increase
* pericardial effusion
* fluid overload
73
Reasons CVP will decrease?
* vol. depleted
74
Normal CVP
1-7mmHg in a spont. breathing pt
75
How does PPV alter CVP?
* artificially increases CVP
* intrathoracic pressure increases & squeezes vessels
76
What are 9 Indications for CVP lines?
1. CVP monitoring
2. PA cath placement
3. Transvenous cardiac pacing
4. Temporary hemodialysis
5. Drug admin
6. Rapid transfusion of fluids/blood
7. Aspiration of air emboli
8. inadequate peripheral access (PICC, midline)
9. repeated blood testing
77
# CVP waveforms
"a wave"
* represents atrial contraction
* occurs after the "P wave"
* atrial depolarization - increased atrial pressure
* provides **atrial kick**
## Footnote
easy to see
78
# CVP Waveforms
"C wave"
* ending of atrial involvement
* isovolumetric contraction of ventricle
* TV closed and ventricle bulges back toward atria
* indirect eval of what's happening in RV
* **follows R wave**
79
# CVP Waveform
"X descent"
* decrease in atrial pressure from "a wave"
* called systolic collapse
* RV starts to collapse - decrease in pressure
* blood fills RA again
* **called X and X1**
## Footnote
easy to see
80
# CVP Waveform
"V wave"
* venous filling of the atrium
* during late systole - TV closed
* peaks just after "T wave"
## Footnote
hard to see
81
# CVP Waveforms
"Y descent"
* TV opens - initial blood flow into ventricle
* diastolic collapse
* hard to see
82
# Abnormal CVP Waveforms
A-fib:
* absence of "a" wave b/c atria aren't contracting well
* larger "c" wave - more vol. when it finally contracts
83
# Abnormal CVP Waveforms
Tricuspid Regurgitation
* no "x" descent - valve is incompetent **blood leaking back into RA & poor filling of RV**
* don't have consistent filling
84
# Abnormal CVP Waveforms
Tricuspid Stenosis
* tall "a" wave b/c of back pressure - inability for RA to effectively contract
* "Y" descent masked by tall a wave
85
# PA catheter
What is the purpose of the balloon?
* used to float catheter down through PA where it can be wedged in place
86
# PA Cath
What does the PA cath tell us info about when the balloon is inflated?
* the balloon isolates everything behind it
* **tells us what the left heart is doing**
* TEE may be more effective though!
87
# PA Cath
Which lumen monitors the PAP?
* distal lumen
88
# PA cath
which lumen monitors the CVP?
* proximal lumen
89
# PA cath
What lumen leads to the balloon?
3rd lumen
90
# PA Cath
what lumen leads to the temperature thermistor?
* 4th lumen - proximal to the balloon
91
What is the preferred insertion site for a PA cath?
* R IJ
92
# PA cath
At what point upon insertion is the balloon inflated?
* once you reach the RA
93
# PA cath
How long is the cath?
What intervals is it marked in?
* 110cm long
* marked @ 10cm intervals
* thin line = 10cm
* thick line = 50cm
94
# PA Cath Depth
What is the depth at the RA?
20-25cm
95
# PA cath depth
What is the depth at the RV?
30-35cm
96
# PA Cath Depth
What is the depth at the PA?
* 40-45cm
97
# PA Cath Depth
What is the depth when the PA cath is wedged?
* 45-55cm
98
# Complications of PAC
Are dysrhythmias, PVCs, V-tach considered complications?
* no; we know it is going to happen b/c myocytes are irritated
99
# Complications of PAC
What are 6 associated complications?
1. transient RBBB/complete heart block
2. catheter knots (open cardiac procedures)
3. pulmonary infarct if PA cath inadvertently inflated = tissue not being perfused beyond this
4. PA rupture (tissue under pressure)
5. Endocarditis
6. Valve injury
100
# Complications of PAC
What are symptoms of PA rupture?
* hemoptysis - coughing up blood
* hypotension
101
# Complications of PAC
How can we prevent endocarditis and valve injuries?
* remove cath in 1st 12-24 hours post surgery
102
# Complications of PAC
What is the treatment for PA rupture?
1. adequate oxygenation (endobronchial intubation w/ SLT or DLT)
2. PEEP (tamponade bleeding - stops adequate perfusion to heart)
3. reverse anticoagulation - protamine **do not do if on bypass**
4. float baloon into rupture/withdraw catheter
5. defintive surgical therapy (oversew PA or resection)
103
# PA cath
What pressures are monitored w/ the PA cath?
1. Pulm artery pressure (PAP)
2. Pulm. Artery Wedge Pressure (PAWP)
3. Left Ventricular End-diastolic Pressure (LVEDP)
104
# PA cath
The PAWP provides an indirect measurement of what?
What pressure can be used as an alternative to a wedge pressure?
* LA pressure
* PAD pressure can be used if you can't get cath to wedge
* PAD = more consistent monitoring of "wedge"
105
# PA cath
Where should the PAC tip be located?
* zone 3: Pa>Pv>PA
* arterial pressure > venous pressure > alveolar pressure
* blood present throughout entire cardiac cycle!
106
# PA Cath
What things can lead to a poor estimate of LVEDP?
1. compliance
2. aortic regurg: artifificially increases #s **(blood leaking back into LV during systole)**
3. PEEP: increasing thoracic pressure & pressure on heart
4. VSD - altered flow
5. mitral stenosis/regurg
## Footnote
**important to know pts valvular status - TEE**
107
# Abnormal PAC Waveforms
Mitral Regurg:
* Tall "V" wave
* "C" wave fused w/ "V" wave
* No "X" descent
* **no sensitivity to severity of MR**
108
# Abnormal PAC Waveforms
Mitral Stenosis
* slurred, early "y" descent
* "a" wave may be absent **(associated w/ a-fib)**
* cardioversion may be necessary for pts w/ mitral valve replacements
109
# Abnormal PAC Waveforms
Acute LV MI
* tall "a" waves d/t non-compliant LV (kid w/ fixed ventricular vol)
* LV systolic dysfunction = increased LVEDV and LVEDP
* PAWP increases
110
What did mixed venous oximetry use to be used for?
* monitor of CO and shock states
* **now we use non-invasives/TEE/lactate**
111
# Mixed Venous Oximetry
Fick Equation Rearranged
SvO2 = SaO2 - VO2/Q x 1.34 x Hgb
* If Hb, arterial sat, and oxygen consumption stay the same = **mixed venous sat an indirect indicator of CO**
## Footnote
problem: these are all changing
112
CO =
HR x SV
113
**CO (L/min)**
avg:
range:
formula:
* avg: 5.0
* range: 4.0-6.5
CO = HR x SV
114
**SV (mL)**
Avg:
Range:
Formula:
* avg: 75mL
* range: 60-90mL
SV = EDV - ESV
115
**SVR (dynes/sec/cm5 or cgs)**
avg:
range:
formula:
* avg: 1200 dynes/sec/cm5
* range: 800-1600 dynes/sec/cm5
**SVR = (MAP-CVP/CO(L/min)) x 80
or SVR = (MAP - RAP/CO(mL/sec)) *pru***
116
**PVR (dynes/sec/cm5)**
avg:
range:
formula:
* avg: 80 dynes/sec/cm5
* range: 40-180 dynes/sec/cm5
**(PVR = MPAP - PAWP/CO) x 80**
117
**Mixed Venous O2 Sat (SvO2)**
avg:
range:
formula:
* avg: 75
* range: 70-80
**SvO2 = (SaO2 - VO2/Q x 1.34g/dL x Hb)**
118
# PA cath
How do we perform bolus thermodilution CO measurement?
* inject 10mL of cold fluid
* change in temp measured downstream
* 3 avg. attempts
* CO inversely proportionate to degree of change
119
# Bolus thermodilution
**results**
low CO:
high CO:
* low CO: takes longer to get back to normal temp
* high CO: gets back to normal temp quicker
120
# Bolus Thermodilution:
What 5 things can cause inaccuracies?
1. intracardiac shunts
2. tricuspid/pulmonic regurg
3. mishandling of injectate (not done consistently)
4. fluctuations in body temp
5. rapid fluid infusion (cold blood)
121
# PA Cath
How do continous CO devices work?
* still uses a thermistor
* releases heat from filament in RV
* temp change measured @ thermistor
* updated q 30-60sec - gives avg over 3-6 min
122
# PA Cath
Compared to thermodilution, continous CO devices are more ________ & ________. And they are more accurate during ____.
* accurate and precise
* PPV
123
How do pulse contour devices work?
What 3 things do they measure?
* they use AUC arterial pressure tracings
* estimate CO, pulse pressure, and SVV
124
What treatment can pulse contour devices guide?
* if hypotension is more likely to respond to fluid or medications (SVV > 10% = fluid)
125
How accurate are pulse contour devices compared to thermodilution when estimating CO?
* +/- 0.5L/min compared to thermodilution
126
What 3 things can cause inaccuracies with pulse contour devices?
* A-fib
* site of arterial puncture
* quality of arterial tracing (vasopressors, vasodilators, vascular abnormalities in the artery)
127
# Echo
What is m-mode used for?
* narrow beams to measure tissue planes
* ex: ventricular wall mass
128
# Echo
what does the 2-D image provide?
What does doppler allow?
* 2-D: shows real time motion & function
* doppler: can determine speed and direction of flow
129
# Echo
What are potential problems in using a transthoracic issue?
* obesity
* pt does not tolerate lying flat
130
# Echo
When using a TTE - what structures will be at the top of the image?
* anterior structures
* they are closest to the transducer
131
# Echo Windows
Where anatomically is the parasternal view?
* 3-5 ICS
132
# Echo Windows
Where anatomically is the apical view?
* at the PMI
133
# Echo Windows
Where anatomically is the subcostal view?
* just below the xiphoid
134
# Echo FOCUS views
What does the parasternal long axis view look at?
* measures LA, LV and Ao Root
* provides a great overall view
135
# Echo FOCUS views
What does the parasternal short axis view assess?
* LV function
* LV volume assessment
136
# Echo FOCUS views
What does the Apical 4 chamber view assess?
* RV & LV size
* TV and MV function
* Descending Ao
137
# Echo FOCUS views
What does the Subcostal 4 chamber view assess?
* all 4 heart chambers
* can see fluid around the heart
138
# Echo FOCUS views
What is the subcostal IVC view assessing?
* the diameter and collapsibility of the IVC (fluid status)
139
What can an intra-op TEE be used for?
* rescue tool
* determines valve/volume issues
* aids in decision making
140
What structures are at the top of the image when doing a TEE?
* posterior structures b/c they are closer to the transducer
141
What are 2 contraindications to TEE?
* esophageal varices
* laparoscopic banding
