CV Monitoring Flashcards
(109 cards)
1
Q
How many electrodes are used for bipolar limb leads?
A
2 electrodes (1 positive, 1 negative)
Einthoven’s triangle
2
Q
What are the augmented leads?
A
- Uses positive unipolar limb lead
- Oriented between limb leads
- AVR: Right arm +
- AVL: Left arm +
- AVF: Left foot +
3
Q
How would you orient precordial leads to get a picture of the right heart?
A
Flip leads to the right chest
4
Q
What is the orientation of the precordial leads?
A
5
Q
12 lead EKGs can be used to identify:
A
- Rhythm
- Conduction delays
- Infection
- Damage
6
Q
What is the criteria for a right bundle branch block?
A
- QRS >0.12 sec (3 small boxes)
- From conduction delay
- Looks like rabbit ears
7
Q
What can a left bundle branch block mimic?
A
Anteroseptal MI
8
Q
How is right atrial hypertrophy diagnosed?
A
- Initial component of P larger in V1→taking longer to depolarize atria
- Height >2.5mm in any limb lead
9
Q
What are causes of right atrial hypertrophy?
A
- LVH, Left atrial enlargement, RVH
- Tricuspid valve disease (stenosis)
- Pulmonic stenosis
10
Q
A
A) Normal
B) RAE
C) LAE
D) RAE and LAE
11
Q
How is left atrial hypertrophy diagnosed?
A
- Terminal portion of diphasic P in V1 larger (up stroke smaller than down swoop)
- Occurs with mitral stenosis and systemic hypertension
12
Q
What are causes of left atrial hypertrophy?
A
- Mitral valve disease (stenosis)
- Aortic stenosis
- All causes of LVH
13
Q
Which lead do we look at to dx BBB and L or R hypertrophy
A
V1
14
Q
What would R waves look like in V6, V5, and V4 in a patient with right ventricular hypertrophy?
A
R waves would be smaller in V6 and gradually get bigger in V5 and V4
15
Q
What causes the electrical changes on EKG from RVH and what are those changes?
A
- Caused by RV wall thickening→ more depolarization toward V1
- QRS in V1 positive, R waves get smaller
16
Q
What are causes of RVH?
A
Pulmonary pathology (COPD, Pulm HTN)
17
Q
What electrical changes are seen on EKG from LVH?
A
- Large S wave in V1
- Larger R wave in V5 (overlapping in image: wouldnt overlap if someone turned the gain down so need to make note if you do that)
18
Q
What are causes of LVH?
A
- HTN
- CHF
- Aortic valve disease
- Coarctation
- MI
- Severe anemia
19
Q
What causes myocardial ishemia?
A
Reduced supply of O2 from the coronary arteries
20
Q
How does myocardia ischemia present on EKG?
A
- Inverted, symmetrical T wave
- 2 contiguous leads
21
Q
How does myocardial injury present on EKG?
A
- ST elevation in 2 contiguous leads
- Signifies acute MI
22
Q
What type of MI is this showing?
A
Anterior (some septal and some lateral)
ST elevation in V2, V3,V4, V5,V6
23
Q
What on an EKG indicates necrosis and confirms dx of old infarction?
A
Q wave→ must be significant (1mm wide or 1/3 QRS tall and 2 related leads)
24
Q
T/F: A Q wave is often present in a transmural MI
A
T: Old/healed MI that went through endocardium to epicardium (through entire muscle mass)
25
Why does a nontransmural MI cause loss of R wave progression in V1-V6?
Abnormal electrical current because it is traveling through dead muscle (no current so decreased R wave progression)
26
What is the treatment of choice for disturbances in cardiac impulse conduction?
Artificial cardiac pacemaker
*SSS in elderly
*Antibrady treatment
27
What types of cardiac pacemakers are there?
- Transthoracic
- Transcutaneous
- Transvenous
*Often required temporarily after cardiac surgery*
28
What is the generator of a pacemaker?
Energy source and electrical circuits
29
What is the lead portion of a pacemaker?
Insulated wire from generator to electrode
30
What is the electrode portion of the pacemaker?
Exposed metal end in contact with endocardium (or epicardial leads)
31
What is a unipolar pacemaker?
Negative electrode in chamber, positive electrode (grounding)
*More sensitive to EMI*
32
What is a bipolar pacemaker?
Both electrodes in chamber are being paced (common, uses less energy)
33
What is a multipolar pacemaker?
Multiple electrodes within 1 lead but multiple chambers
34
What is rate modulation of a pacemaker?
The ability of the pacemaker to sense heart rate changing, respiratory rate changing, and cardiac output changing and adapt based on what pt is doing
35
What is multisite pacing?
Allows for biventricular pacing with AICDs
36
What does "inhibited" pacemaker code mean?
If intrinsic activity is perceived, chamber is not paced
37
What does "triggered" pacemaker code mean?
Pacemaker discharges if intrinsic activity is sensed, used only for testing on devices
38
What changes in the patient/sensors cause a "rate modulation" pacemaker code?
- Vibration
- Motion
- Minute ventilation
- Right ventricular pressure
39
What is "multi-site pacing" used for?
Afib or dilated cardiomyopathies
40
What is a DDD pacemaker?
Dual pacing
Dual sensing
Dual response
*2 spikes= pacing both chambers*
41
What type of pacemaker is this showing?
Ventricular pacing
(DDD is sensing both but only pacing ventricle)
42
What are some perioperative considerations for pts with pacemakers?
- Turn filter OFF on cardiac monitor to see pacer spikes
- Grounding pad distant from pacemaker (put on thighs or butt--as far away as you can)
- Interrogate pre/post op (per policy to make sure cautery didn't effect it)
43
Where are pacemaker wires located in Biventricular pacing?
3 chamber→ Right atrium, Right ventricle, Left ventricle (goes through septum)
44
What are the benefits of Cardiac Resynchronization (CRT)?
- Improves RV-LV activation time
- Increases EF%
45
What are the requirements for Bi-V pacing?
- Moderate/severe HF (EF <30-35%)
- Intraventicular conduction delays (BBB→ QRS 120ms or >, usually on left side side)
- NYHA class III or IV despite optimization (severe failure symptoms, limited ADLs)
- History of cardiac arrest
46
What are common left sides intraventricular conduction delays?
Anterior or posterior fascicular block
47
What is the function of a magnet with a pacemaker?
- Disables anti-tachycardia therapy
- Detects battery life response→ decreases pulse amplitude or width, intensified follow-up, elective replacement for end of life
48
What are perioperative care considerations for AICD/BiV pacemakers?
- Optimize patient condition
- Turn filter OFF on cardiac monitor
- Bipolar cautery
- Back-up pacing ability
- interrogation postop
49
What type of cautery should be used with a patient that has a Bi-V pacemaker?
Bipolar cautery→ Directs current between electrodes instead of through body (minimize EMI)
50
What rhythms can implanted cardioverter-defibrillators terminate?
V-fib or V-tach
51
How do implanted cardioverters/defibrillators recognize VF/VT?
- Measure R-R intervals
- Abrupt onset (SVT usually gradual onset so AICD wouldnt shock)
- Looks at QRS if its normal or wide
- Looks at amplitude
52
What side of the patient is this showing?
Right side of patient→ carotid is medial IJ is lateral
53
Where is CVP measured?
Pressure measured at the junction of vena cava and RA (Atrial caval junction)
*Highly depended on blood volume and vascular tone*
54
What are typical depths for RIJ, LIJ, RSC, LSC?
55
What is CVP used to assess?
Blood volume and right heart function (good to look at trends)
56
What is normal CVP for awake pt breathing spontaneously?
1-7mmHg
57
What are some indications for CVP lines?
- CVP monitoring
- PA catheter placement
- Transvenous cardiac pacing
- Temporary hemodialysis
- Drug admin
- Rapid infusion of fluid/blood
- Aspiration of air emboli
- Inadequate peripheral access
- Repeated blood testing
58
What does the "A" wave represent on CVP?
- First wave
- Atrial contraction
- Occurs after "P" wave
- Atrial pressure increases and provides "atrial kick"→ extra 20% atrial volume
59
What would the A wave look like on CVP if there is no atrial kick?
Shorter A wave or No A wave
60
What does the "C" wave represent on CVP monitor?
- Interrupts the decreasing atrial pressure
- Isovolumetric contraction of ventricles
- Tricuspid valve closed and ventricle starts to bulge toward atria
- Follows R wave
61
What does the "X descent" signify on CVP?
- Decrease in atrial pressure from A wave through ventricular systole
- Systolic collapse
- Sometimes called X and X1
*2 pieces of it separated by C wave*
62
What is the "V" wave on CVP?
- Venous filling of atrium
- During late ventricular systole (tricuspid valve remains closed)
- Peaks just after the "T"
63
64
How would A fib effect CVP waveform?
- Absence of A wave
- Larger C wave (more volume)
65
How would tricuspid regurgitation look on CVP?
No X descent (valve is incompetent)
66
How would tricuspid stenosis look on CVP?
- Tall A wave
- Slow/diminished Y descent
67
What are the lumens of a pulmonary artery catheter and what do they monitor?
- Most Distal: PAP
- 30cm proximal: CVP
- 3rd lumen: Leads to a balloon near the tip
- 4th lumen: proximal to the balloon, temperature thermistor
68
When was PA catheter introduced?
1970 (by Swan, Ganz, and colleagues)→ assessment tool for acute MI pts
69
What is the preferred site for PA catheter?
Right IJ (shorter distance and smoother turn into RA)
70
How is a PA catheter advanced? What should you be watching/looking for?
- Balloon is deflated until you reach RA
- Time advancement with heart beat
- Common to see ectopy when in RV
71
Why do most facilities stop pulmonary catheter at the PA and dont go to wedge?
If you go to wedge (past PA) risk for obstructing artery and potential puncture
72
Where are you at for PA catheter insertion at each of these waveforms?
A) Right atrium
B) RV
C) PA
D) Wedge (past PA)
73
How long are most PA catheters?
110cm (marked at 10cm intervals)
74
What is the guideline depth (in cm) for reaching RA, RV, PA, and wedge with pulmonary catheter?
- RA: 20-25cm
- RV: 30-35cm
- PA: 40-45cm
- Wedge: 45-55cm
*good to know estimated depth as well as looking at clinical waveform*
75
What are complications associated with PA catheters?
- Dysrhythmias (PVCs, VT)
- Transient RBBB or complete heart block
- Catheter knots
- Pulmonary infarction (if you go to wedge and stay there)
- Pulmonary artery rupture
- Endocarditis
- Valve injury
76
What are symptoms that possibly indicate pulmonary artery rupture?
- Hemoptysis
- Hypotension
77
What is the treatment for pulmonary artery rupture?
- 100% O2
- intentional R mainstem to protect blood from getting into other lung
- PEEP (help tamponade the bleeding)
- Reverse anticoagulation (unless on bypass)
- Float balloon into rupture vs withdrawing catheter
- Definitive surgical therapy (oversew pulmonary artery, lobe resection)
78
Which pressures are monitored via pulmonary artery catheter?
- Pulmonary artery pressure
- Pulmonary artery wedge pressure
- Left ventricular end-diastolic pressure
79
What is PAWP an indirect measurement of? Where should the PA catheter tip be to monitor PAWP?
- Indirect measurement of LA pressure
- PAC tip in zone 3
80
What might cause a falsely elevated EDP?
Aortic regurgitation→ volume isnt actually bigger there is a regurg issue
81
Why is a PA catheter a poor estimate of LVEDP?
- Compliance
- Aortic regurgitation falsely elevates
- PEEP
- VSD
- Mitral stenosis/regurg
82
How does mitral regurgitation impact PAC waveform?
- Tall V wave
- C wave fused with V wave
- No X descent
- No specificity/sensitivity to severity of MR d/t LA compliance and LA volume
83
How does mitral stenosis impact PAC waveform?
- Slurred, early y descent
- A wave may be absent d/t frequent association with a-fib
84
How might acute LV myocardial MI impact PAC waveforms?
- Tall A waves d/t non-compliant LV
- LV systolic dysfunction increases LVEDV and LVEDP
- PAWP increases
*Hypokinesis or akinesis of wall on echo*
85
How do you calculate mixed venous hb sat?
86
What happens to mixed venous saturation if cardiac output drops?
Mixed venous saturation decreases (indirect indicator of CO)
87
What might low venous saturation indicate?
Anemia→ blood transfusion needed
88
What is the average CO, SV, SVR, PVR, and mixed venous O2 sat measured from PAC?
89
What is the gold standard for measuring cardiac output?
Bolus thermodilution
90
What is bolus thermodilution?
- 10mL cold injected into RA lumen(change in temp measured downstream)
- measured PA blood by thermister
- 3 attempts averaged (variation in speed each time so we want to get average)
- CO inversely proportionate to degree of change
91
What % change in bolus thermodilution is significant?
subsequent changes of 13%
92
What are these thermodilution curves showing?
The area under the thermodilution curve is inversely proportional to the cardiac output
93
What causes inaccuracies with thermodilution?
- Measures right heart, assumes left heart
- Intra-cardiac shunts: VSD, ASD
- Tricuspid/pulmonic regurg
- Mishandling of the injectate
- Fluctuation in temp (following bypass)
- Rapid fluid infusion
94
How can cardiac output be measured continuously? How often does it update?
- Small amounts of heat are released from filament in RV continuously→ measured at thermistor which gives continuous number of CO
- Update every 30-60 seconds, averaged over 3-6min
- More accurate during positive pressure
95
How does continuous cardiac output compare to thermodultion?
- Reproducibility/precision is better
- Delays updated information in unstable patients
96
What is the function of pulse contour devices?
- Uses AUC (area under curve=SV) arterial pressure tracings
- Estimates CO. pulse pressure, SVV
- Indicated whether hypotension is likely to respond to fluid (if SVV >10%)
- Calculates ventricular compliance from end diastole to end systole
97
What causes inaccuracies with pulse contour?
- Afib
- Site of arterial puncture
- Quality of arterial puncture (affected by pressors- not picking up CO as well)
- Requires frequency re-calibration
98
What is used in echocardiography?
- High frequency ultrasound waves
- Density x velocity (sound through tissue)
- M-mode (narrow beams to measure tissue planes ie ventricular wall mass)
- 2-D (real time motion, shows function)
- Doppler (Can determine speed and direction)
99
There are ______ key views for FoCUS method TTE:
5→ anterior structures closest to transducer (at top of image)
Comprehensive exam: 28 views
100
Where are the parasternal, apical, and subcostal windows located?
- Parasternal: 3-5 ICS
- Apical: L midclavicular 5 ICS (Point of maximal impulse)
- Subcostal: Just below xiphoid
101
What does the parasternal long axis measure?
LA, LV, Aortic root
102
What does the parasternal short axis measure?
LV function and volume
103
What does apical 4 chamber measure?
- RV vs LV size
- Tricuspid and mitral valve function
- Descending aorta
104
What does the subcostal 4 chamber look at?
- 4 chambers
- pericardial effusion often next to right heart
105
What can you see when looking at subcostal IVC on echo?
Diameter, collapsibility especially in spontaneous respiration
106
What is the role of intraoperative TEE?
- Intraop monitor
- Rescue tool
- Assessment of valve function
- Decision making
*Posterior structures are closer to transducer (at top of image)*
107
What are contraindications for TEE?
- Esophageal varices
- Laparoscopic banding→ restrictive around the fundus of the stomach
108
What is a common description of the aortic valve under ultrasound?
Mercedes sign
109
What is the purpose of visualizing the aorta under ultrasound?
Looking for calcification around aorta (white feedback)→ wouldnt want to cannulate for bypass
