Exam 1: Cardiac Monitoring Flashcards
What is shown on this EKG?
Right BBB (use the “turn signal” method on V1 only)
S9
What is shown on this EKG?
Left BBB (“turn signal” goes down)
S10
What is indicated by the pink highlighted portion of the P wave below?
Right Atrial Hypertrophy
- Initial component of P is larger in V1
- Height is > 2.5mm in any limb lead
S11
What is indicated by the blue highlighted portion of the P wave below?
Left Atrial Hypertrophy
- Terminal portion of diphasic P in V1 is larger
- occurs with mitral stenosis and systemic HTN
S12
P-waves for lead II and Lead VI are shown below. What would be indicated by this EKG waveform?
Bi-atrial enlargement
S12
What is indicated in this EKG?
RV Hypertrophy
- RV wall is thick therefore we have more depolarization toward V1
- QRS in V1 positive - R waves get smaller
not on the slide: but we also see more negative deflection in lead I - indicating the current travels more right
S13
What is this EKG showing?
LV hypertrophy
- Large S wave V1; Larger R wave V5
- depth of V1 and height of V5 = 35mm
S14
What EKG sign would be indicative of myocardial ischemia? (ischemia, not infarction)
Inverted symmetrical T-waves
- caused by a reduced supply of O2 from the coronary arteries
S15
What EKG sign would be indicative of non-salvageable tissue damage (infarct) post acute myocardial infarction?
Pathological Q-waves: 1mm wide or ⅓ the height of R-wave in 2 related leads.
S17
Cardiac pacemakers are the treatment for choice for?
- Elderly or SSS
- anti-bradycardi treatment (either from pathology or medication)
- (often required temporarily after cardiac surgery)
S19
3 types of pacemakers and what do they consist of?
- Transthoracic, transcutaneous and transvenous
- Consists of pulse generator and electrode leads
S19
What type of pacemaker is most sensitive to electromagnetic interference?
Unipolar
- unipolar leads are negative eletrodes in chamber with the postitive (grounding electrode)
S20
What is the bipolar electrode?
both electrodes in chamber being paced
S20- Uses less energy; common
Do Bipolar or Unipolar pacemakers utilize less energy?
Bipolar uses less energy (more efficient)
most common
S20
What are the multipolar leads?
multiple electrodes within 1 lead but multiple chambers (some leads cross the septum - biatrial or biventricular)
S20
What type of electrocautery is more safe for patients with permanent pacemakers?
Bipolar Cautery
Lecture
In what situations would Bi-ventricular pacemakers be utilized?
Anywhere were resynchronization therapy is indicated.
- HF (30-35% EF)
- BBB
- Hx of cardiac arrest
S25
Bi-Ventricular pacing has leads where?
- RA
- RV
- LV (these are trans-septal)
S25
Purpose of Bi-Ventricular pacing
Cardiac resynchronization (CRT)
- improves RV-LV activation time
- increases EF
S25
What is the I generic code for pacemaker function and the possible modes
I indicate the chambers paced
- 0=no chamber paced
- A = atrium paced
- V = ventricular paced
- D = dual chamber paced
S21
What is the II generic code for pacemaker function and the possible modes
II indicate the chamber sensed
- 0 = none
- A = Atrium
- V = Ventricle
- D = dual sensed
S21
What is the III generic code for pacemaker function and the possible modes
III indicate the response to the sensing
- 0 = none
- T = triggered i.e. the pacer is triggered to act based on the sensing
- I = inhibited i.e. the pacer does not act based on the sensing
- D = dual (most common) will both trigger and inhibit
S21
What is the IV generic code for pacemaker function and the possible modes
IV indicates rate modulation of the pacer
- 0 = no rate modulation
- R = there is rate modulation
S21
What is the V generic code for pacemaker function and the possible modes
V indicates if there is multisite pacing
- 0 = none
- A = atrial
- V = ventricle
- D = Dual
S21
What is the difference between Inhibited and triggered pacemaker mode?
- Inhibited: if intrinsic activity is perceived, chamber is not paced
- Triggered: pacemaker discharges if intrinsic activity IS sensed; used currently only for testing of devices
S22
Magnets will make the Pacemaker default into what mode? (older models)
Asynchronous pacing with no rate modulation
- DOO vs VOO
- this might produce no change in pacing
- Detects battery life response (decreases pulse amplitude or width) Therefore we sometimes have inadequate capture
S27
Perioperative care of AICD and BiV
- Optimize patient condition
- Turn filter OFF on cardiac monitor
- Want Bipolar cautery instead of monopolar
- Back-up pacing ability
- Interrogation postoperatively
Consider transQ pads if device isn’t working
S28
What is an AICD?
Inplantable Cardioverter-Defibrillator
- battery powered to terminate VF or VT
- it measures R-R intervals
- if the R-R are too short, sometimes it can shock like in SVT (10% inappropriate)
S29
Criteria for an AICD shock
- Onset abrubt or gradual
- VT/VF
- R-R interval too short (SVT)
- Variable or consistent R-R interval
- QRS could be normal or wide
S29
What is a CVP?
- Pressure measured at the junction of vena cava and right atrium (Highly dependent on blood volume and vascular tone)
- Used for assessment of blood volume and RIGHT heart function (trends instead of 1 number)
- normal, awake, spont breathing = 1-7mmHg
S32
What causes an (a) waveform on a CVP?
- Atrial contraction
- occurs after the P wave on EKG
- increases atrial pressure
- Provides the atrial kick
S34
What causes the (c) waveform on a CVP?
- Interrupts the decreasing atrial pressure
- Isovolumetric contraction of the ventricle
- Tricuspid valve closed and ventricle bulges toward the atria
- Follows “R” wave
S35
What causes the x descent on the CVP?
- Decrease in atrial pressure from a wave through ventricular systole
- called systolic collapse
- sometimes called X and X1
S36
What causes a (v) waveform on a CVP?
- Venous filling of the atrium
- during late systole - when tricuspid valve is still closed
- peaks just after T wave on EKG
S37
What causes the Y descent on the CVP?
- Tricspid valve opens
- called diastolic collapse
S38
An h-plateau occers immediately before the ____ wave.
a-wave
Schmidt
The y descent happens after the ______ wave.
v-wave
S38
What is the H-wave or H-plateau?
Diastolic plateau (not a lot of blood movement until atria contract to produce the a-wave)
From Schmidty
The x descent happens after the ________ wave
c-wave
S38
During atrial fibrillation, loss of the ___ wave and enlargement of the ___ wave occurs to the CVP waveform.
- loss of A-wave
- enlargement of C-wave
S39
What characteristics are seen on a CVP waveform in a patient with significant tricuspid regurgitation?
- Tall Systolic C-V wave
- Loss of X-descent
Very similar to RV waveform
S39
What characteristics are seen on a CVP waveform in a patient with significant tricuspid stenosis?
- Tall A-wave
- Small Y-descent
S39
Describe a Swan-Ganz Catheter in detail.
Flip for picture.
S40
What does each lumen do in the PA catheter?
- Most distal: monitors PAP
- 30cm proximal: monitors CVP
- 3rd lumen: leads to the balloon to wedge the PA
- 4th lumen: lies just proximal to the balloon, also has the termperature thermistor
S41
What is the preferred site for PA catheter placement?
Right IJ
S42
Where is the PA catheter at based on the waveform below?
Right Atrium
S42
Where is the PA catheter at based on the waveform below?
RV
S42
Where is the PA catheter at based on the waveform below?
Pulmonary Artery
S42
Where is the PA catheter at based on the waveform below?
Wedged
S42
What is the total length of the PA catheter?
110 cm marked at 10cm intervals
S43
Normal PAC depth for:
- RA
- RV
- PA
- Wedge
- RA: 20-25cm
- RV: 30-35cm
- PA: 40-45cm
- Wedge: 45-55cm
S43
7 Complications of PAC
- Dysthythmias (PACs, PVS, VT runs)
- RBBB or complete HB
- Catheter knots
- Pulmonary infarction
- Pulmonary artery rupture
- Endocarditis
- Valve Injury
VERB DIK
S44
What PA catheter complication is associated with very high mortality? What are the presenting s/s?
Pulmonary artery rupture
- Hemoptysis (Bright red and copious)
- Hypotension
S44
How are PA ruptures treated?
- ↑ Oxygenation
- ETT (might need double lumen)
- PEEP (to tamponade bleeding - very temporary)
- Reverse anticoagulation (unless on bypass)
- Tamponade bleed w/ PA balloon maybe
- Definitive surgical repair
Thoughts and prayers
S45
Cannot reverse anticoag while on bypass r/t pt will be “deader than dead” -Corn 8/3/24
How do you take a PAWP?
- this is an indirect measurement of LA pressure
- PA diastolic can be used as an alternative (but issues with that too)
- PAC tip should be in West Zone 3
S46
What are the drawbacks of estimating the wedge pressure with the LVEDP?
- Poor estimate of:
- Compliance
- Aortic regurgitation (artificially increases)
- PEEP (artificially increases)
- VSD (ventricular septal defect)
- Mitral stenosis/regurg (weird wave)
S47
What would a PAC/CVP waveform look like in a patient with mitral regurgitation?
- Tall V-wave
- C & V wave fused
- No X-descent
S48
What would a CVP waveform look like in a patient with mitral stenosis?
- Slurred, early Y-descent
- A wave may be absent d/t frequent association with a-fib
S49
How will the PA catheter waveform present with an acute LV MI?
- Tall A-waves d/t non-compliant LV
- Increased LVEDV & LVEDP
- PAWP increases
S50
The Mixed venous equation is a rearrangement of the ____ equation, and the equation is ____
Rearrangement of the Fick equation
S51
What is the typical range for mixed venous O₂ saturation and what is the O2 carrying capacity of Hgb?
- 70 - 80 % (average 75)
- 1.34
S54
What is the typical range for SVR?
800 - 1600 dynes/sec/cm5 (average1200)
S54
What is the typical range for PVR?
40 - 180 dynes/sec/cm5 (average 80)
S54
What is the typical range for stroke volume?
60 - 90 mL (average 75)
S54
What is bolus thermodilution for the PAC and what is it measuring?
- Cold injected (10ml) and measure a change in temperature downstream
- Injected RA lumen, measured PA blood by thermister
- 3 averaged attempts
We measure CO: CO inversely proportionate to degree of change
Subsequent changes of 13% significant
S55
What would the following cardiac output thermodilution curve indicate?
Low CO (Longer time to return to baseline)
S56
What would a high cardiac output thermodilution curve look like?
S56
Examples of things that would cause thermodilution inaccuracies
- Measures right heart; assumes left heart
we run into problems with the following:- Intra-cardiac shunts
- Tricuspid/pulmonic regurgitation
- Mishandling of the injectate (person dependent)
- Fluctuations in temperature of the pt i.e. Following bypass
- Rapid fluid infusion (Cold blood? cold meds going in?)
S57
How is continuous cardiac output measured?
- Small quantities of heat are released from filament in RV (measured at thermistor)
- Updated q 30-60 seconds; averaged over 3-6 minutes
- Compared to thermodilution:
- Reproducibility/precision better
- But we have delay in updated information in unstable patients
More accurate during positive pressure
S58
If SVV is > ____% then patient is likely to respond well to fluids for hypotension.
10%
this relys on an algorithm from end diastole to end systole - and calculates ventricular compliance (+/- 0.5L/min compared to thermodilution)
S59
Continuous Cardiac output monitoring and pulse contor inaccuracies
- Atrial fibrillation
- Site of arterial puncture
- Quality of arterial trace (Affected by vasopressors)
- Requires frequent re-calibration (Ideally calibrated initially with a known CO)
S60
How many “views” are in a full echocardiogram?
28 views
S63
What five views can be utilized for a focused TTE?
- Parasternal Long Axis
- Parasternal Short Axis
- Apical Four Chamber
- Subcostal Four Chamber
- Subcostal IVC
S65
What is assessed with a parasternal long-axis view?
- Overall Function
- LA, LV and aortic root
S64
What is assessed with a parasternal short-axis view?
- LV function & volume status
S64
What is assessed with an apical four chamber view?
- RV vs LV size
- Tricuspid & Mitral function
- Descending Aorta
S64
What is assessed with a subcostal four chamber view?
- Pericardial Effusion often next to right heart
- Four chambers
S65
What is assessed with a Subcostal IVC view?
IVC
- Diameter
- Collapsibility (especially in spont respiration)
S65
What are the two main contraindications to intra-operative TEE?
- Esophageal Varices
- Lap Banding
S66
