Cardiac Imaging Flashcards
1
Q
Types of Cardiac Testing
A
- EKG
- Ambulatory ECG Monitoring
- Stress test
- Exercise
- Pharmacologic
- Echocardiogram
- Stress echocardiogram
- CT scan
- MRI
2
Q
EKG
Indications
A
-
Symptomatic patients
- CP, palpitations, fatigue w/SOB, syncope (pass out), seizure
-
Eval/monitoring of:
- Audible abnormalities (arrhythmia, murmur)
- Suspected electrolyte imbalance
- PE
- Congenital heart disorders
- CHF
- Cardiomyopathy (enlargement)
- Poisonings/electrocution
-
Drug monitoring - need regular EKG monitoring
- Drugs that prolong QT (lithium, psych meds)
- Presence of implanted defibrillator/pacemaker (yearly EKG
3
Q
Screening EKGs
USPSTF
A
- Adults at low risk of CVD events: Recommend AGAINST EKG screening (Grade D) → can lead to unnecessary tests
- Adults at intermediate or high risk: Insufficient evidence for screening (Grade I)
-
Athletes - sports physical
-
History and physical most important
- Worried about electrical abnormalities (asymptomatic arrhythmias) while exercising)
-
History and physical most important
- Pre-operative exams
- Certain occupations may require screening EKG: cataract
If patient has no symptoms indicating an EKG → no need to test again
4
Q
How to assess CVD risk by USPSTF?
A
Use Pooled cohort calculator
10-year ASCVD risk < 7.5% = low
“” >/= 7.5% elevated risk
5
Q
Ambulatory EKG monitoring
A
Provides data over extended period of time
6
Q
Ambulatory EKG monitoring Indications
A
- Arrhythmias s/s
- Eval effectiveness of arrhythmia therapy
- Screening for asymptomatic arrhythmia
- Eval prognosis post ACS
- Assess for silent ischemia in someone with known/suspected CAD
- DM, women
7
Q
What arrhythmia s/s indicate for ambulatory EKG monitoring?
A
- Unexplained syncope/near syncope
- Episodic dizziness, unexplained recurrent palpitations
- Frequent palpitations/palpitations associated w/other s/s: SOB, dizziness, etc
- Vasovagal event precipitated by something (feel like I’m going to pass out)
- Passing out
8
Q
Types of ambulatory Monitoring
A
- Continuous EKG (Holter)*
- Event (loop) monitors
- Patch monitors*
- Mobile Cardiac Outpatient Telemetry (MOCT)
- Insertable cardiac monitoring
*** = see in primary care
9
Q
Holter monitor
A
- Best for daily or near daily symptoms and/or if continuous monitoring of all cardiac activity is required (gives you most info for shortest time)
- Daily palpitations or dizziness
- Assessment of rate control in afib (short time period to see rate) don’t need 30days, only snippet
- Continuously records heart rhythm
- Usually worn for 24-48 hrs
- 3-5 electrodes on chest
- Patient keeps symptom diary
- Hit a button
10
Q
Patch monitor
A
- Good for pts w/less frequent s/s or need for longer monitoring
- Weekly or every other week s/s
- More convenient and easier for pt to tolerate than Holter
- Small all in one device - ONE electrode
- Record only single lead but can record continuously for up to 30 days
- 3, 7, 14, or 30d
11
Q
Event Monitor
types
A
- Good for less frequent symptoms (weekly or bi-weekly)
- Not recording unless patient hits the button when they’re experiencing s/s → problem is the monitor may not be able to capture the duration while it’s occuring
- Pre-symptom memory loop recorders - “continuous loop event recorder” - always recording and erasing data
- Not for asymptomatic
- Post-event recorders - “non-looping event recorder”
- May miss rhythm problem
- Auto-detect - GOOD FOR ASYMPTOMATIC automatically sends data to provider to interpret
12
Q
Insertable cardiac monitor
A
- May be needed if other event monitors can’t provide enough data
- Use if symptoms are infrequent
- Size of pack of gum
- Can be programmed to record when patient activates it or when s/s occur
13
Q
Cardiac stress tests
Indications? What limitation and other option is there?
A
- Exercise stress testing used in symptomatic, intermediate-risk patients who can exercise and who have interpretable EKG results
- No exercise → pharmacologic stress test
14
Q
When is stress testing NOT used?
A
- In high-risk patients actively evaluated or treated for ACS; it may be used once ruled out ACS for risk stratification
- Exercise stress testing not recommended in asymptomatic, low-risk patients
- None on pt w/acute MI, going to ER w/CP → have it later on
15
Q
Stress testing indications (7)
A
- New CP or angina (not current) ASK THIS!
- Known CAD and new/worsening symptoms (cardiac disease)
- Hx of PCI/re-vascularization (stenting)
- Valvular heart disease - stress ECHO
- New HF or cardiomyopathy - evaluate ischemia as cause
- Pre-operatively in pts w/known cardiac conditions
- Assess heart health prior to cardiac rehab or new exercise regimen
16
Q
Contraindications to Stress Testing
Absolute!
A
- Acute MI w/in 48hrs
- Acute myocarditis/pericarditis
- Rapid Afib or ventricular arrhythmias
- Symptomatic severe aortic stenosis
- Severe anemia, acute illness, infection
- Uncontrolled hyperthyroidism
- Acute aortic dissection, PE, recent CVA (stroke)
17
Q
Contraindications to stress testing
Relative - cardiology would decide
A
- Hypertrophic obstructive cardiomyopathy
- Suspected L main disease > 50%
- Severe HTN, > 200/110 mmHg
- Congestive heart failure (CHF)
- Severe ST depression at rest (unstable angina)uPermanent Pacemakers/ LBBB
- Left bundle branch blocks
- Specific way to stress ppl with these to get data
18
Q
What are the components of a stress test?
A
- Stressor: exercise or pharmacologic
- Imaging modality: EKG, Echo, Nuclear (myocardial perfusion imaging - MPI)
19
Q
Exercise (2 imaging tests) vs Pharmacologic (drug) as stressor
Imaging for each type?
A
- Exercise as Stressor - PREFERRED
- EKG imaging only = Exercise Tolerance Test (ETT) Level 1 stress test
- Nuclear imaging = Treadmill Nuclear Stress Test
- Pharmacologic as Stressor (drug)
- Always includes either nuclear or echocardiogram imaging
- NOT EKG monitoring
22
Q
Can your patient exercise to a satisfactory level?
Algorithm
A
If pt on BBs or other AV blocking agents, or have any conditions (LBBB, paced rhythm) that would inhibit HR increase needed to achieve stress or reduce stress test sensitivity → YES → Pharmacologic
Need to be mental and physical limitations (respiratory, elderly, dementia)
24
Q
Bruce Protocol vs Modified Bruce Protocol (treadmill)
A
- Bruce Protocol - most common in office-based testing - extensively validated
- Modified Bruce Protocol - can be used in patients unable to complete Bruce protocol - going slowly
37
Q
Nuclear Exercise Stress Test
What
A
- Stress radionuclide myocardial perfusion imaging (rMPI)
- Single photon emission CT (SPECT) - common IMAGE
- Can be used in exercise MPI or pharmacologic MPI
OR
- Positron emission tomography (PET) - more exepensive
- ONLY used in pharmacologic MPI
38
Q
Nuclear Exercise Stress Test
Process
A
- IV Radioactive tracer administered → wait 30m → RESTING pictures taken 1st
- Exercise/stress inducer starts → 2nd tracer administered → STRESS pictures taken
- Total time 2-3hrs → longer than ETT
- Compare REST VS STRESS pictures → see how well heart is perfused → cardiologist interprets this
39
Q
SPECT imaging interpretation
A
- Gamma radiation measured directly
- Images after 45 minutes of rest are compared to stress images
- Nuclear imaging - “cold spot” areas are considered areas of low or no blood flow → less activity
- Interpretation based on rest images
- Re-perfused (ischemic area) → reversible defect
- Fixed defect (infarct area)
45
Q
TTE
A
- Most common
- Less invasive with no prep
- Image quality affected by amount of tissue between transducer and chest
- Difficult to see posterior images
