Flashcards in Cardiac Stress Testing Deck (32)
Indications for cardiac stress testing include:
1. Establish a diagnosis of CAD
2. Assessment of prognosis and functional capacity (stable angina or post MI)
3. Assess response to therapy
4. Evaluate pre-operative cardiac risk
5. Evaluate asymptomatic individuals for CAD (pilots, police, firefighters, middle aged persons wanting to start a vigorous exercise program)
6. Evaluate for exercise-induced arrhythmias
What possible CAD patients are indicated for stress testing? 2
2. Asymptomatic with abnormal EKG
What kind of therapy would we want to assess? 2
Contraindications to stress testing
1. Acute MI
2. Unstable angina
3. Acute pericarditis
4. Acute systemic illness
5. Severe aortic stenosis
6. CHF exacerbation
7. Severe hypertension
8. Uncontrolled arrhythmias
Instruments to use?
Often combined with what? 3
WHo should this be used in? 2
1. Treadmill or bicycle ergometer
2. Often combined with imaging studies
-In low risk patients without baseline ST segment abnormalities or
-when anatomic localization is not necessary exercise EKG is the recommended initial procedure
What HR do we want to get them at for exercise EKG?
Whats the most common protocol for this?
What is age predicted HR?
a minimum of 85% of the maximum age predicted heart rate
Most common protocol is the Bruce Protocol increasing the speed and incline every 3 minutes
What is monitored throughout the exercise EKG?
1. EKG is monitored continuously during exercise
2. BP response is noted in each stage of exercise (if blood pressure goes down in exercise it is a measure of severe ischemia)
3. Symptoms are noted
Information obtained from EXERCISE:
1. Exercise duration and tolerance
2. Reproducibility of symptoms with activity
3. Heart rate response to exercise
4. Blood pressure response to exercise
5. Detection of stress induced arrhythmias
6. Assess the effectiveness of antianginal medications
Exercise EKG interpretation
What is the criteria for a positive test?
Using this criteria _____% of pts with significant CAD will have a positive test
But _____% of those without significant disease will also have a positive test
Criteria for a positive test is
1. 1mm horizontal or
2. downsloping ST segment depression measured 80 ms after the J point
Exercise EKG interpretation – High risk for significant ischemia
1. BP drop during exercise
2. > 2mm ST depression
3. ST depression that is downsloping
4. ST depression or symptoms at low work loads less than 6 min or HR less than 70% of maximum age predicted HR
5. ST depression that does not resolve quickly in the recovery phase
Risks of exercise testing
1. 1 MI or death per 1000 patients
2. Stress induced arrhythmia
3. Adverse reaction to pharmacologic stress agent
The mean sensitivity improves up to about 85% with ______?
What are the kinds of stress imaging?
1. Cardiac nuclear perfusion imaging (myocardial perfusion scintigraphy)
2. Stress echo
What are the kinds of stresses we can do to do the stress imaging tests? 2
Regular exercise stress
What are the drugs that we use for pharmalogical stress?
1. Dobutamine (positive inotropic and chronotropic agent) used for both tests.
2. Adenosine or persantine (potent vasodilators)- wont dilate because its fibrous. Can only be used for CNP
Indications for stress imaging ?
1. When the resting EKG is abnormal
2. Confirmation of the results of an exercise EKG when results don’t align with clinical impression
3. To localize the region of ischemia
4. Distinguish ischemic from infarcted myocardium
5. Assessment of revascularization post stent or surgery
6. Evaluate prognosis
What things could we see if the resting EKG is abnormal?
2. baseline ST-T changes,
3. low voltage
1. Myocardial perfusion scintigraphy with SPECT is also called what? 2
2. The myocardial uptake of the radionuclide tracer is proportionate to what?
3. Positive in about _____% of patients with significant CAD and in _____% of patients without disease
1. AKA radionuclide imaging or nuclear stress test
2. myocardial perfusion at the time of the injection (all the living cells in the heart will take this up)-make sure that perfusion at higher work loads is good as well.
Myocardial perfusion scintigraphy with SPECT procedure:
1. When are nuclear images taken in this test? 2
2. What kind of stresses do we administer? (most common, next common) 3
1. Nuclear images taken before and after exercise
--Exercise is completed with a treadmill (same protocol as an exercise EKG)
If patient unable to exercise pharmacologic stress is completed with
--Adenosine (most patients)
Stress echocardiography- JUST THE LEFT VENTRICLE.
Echocardiographic images obtained with the patient 1._____, 2.___ and 3.__________ ____ _______?
3. immediately post exercise
What is the stress echo testing for?
Evaluation for wall motion abnormalities of the LV- needs blood supply if area is lacking blood supply at higher demand it is not working the way it should
How is stress administered in stress echo?
1. Exercise is completed with a treadmill
2. If unable to exercise pharmacologic stress is completed with dobutamine (+inotrope + chronotrope)
Images obtained are of the ____ ______
A stress echo report will give you information regarding the presence or absence of ________
it WILL NOT give you information about what (4)?
They do not image the rest of the heart
1. the valves,
2. chamber sizes,
3. hypertrophy or
1. When are stress echo images taken?
2. What will the echo detect? 3
3. Duration compared to nuclear test?
5. Sensitivity and Specificity?
6. What is it not very good at diagnosing? 2
7. What can it be limited by? 2
1. Echo images obtained before and after stress
--Detect wall motion abnormalities,
--lack of thickening of the LV with stress,
--reduced EF with stress
3. Quicker than nuclear stress
4. Less expensive compared to nuclear
5. Slightly less sensitive but more specific for CAD
6. Not great for
--existing LBBB or
--previous wall motion abnormalities
7. May be limited by
--hyperinflation of the lungs
1. Whats a MUGA scan?
2. What does it use to image?
3. What is this an image of?
4. What does it evaluate?
5. Used often for what?
1. Multi Gated Acquisition Scan
2. Uses radionuclide tracers to image the
4. Evaluates the
--wall motion and
--precisely calculates the EF
5. Often used for evaluation of EF for cancer patients on cardiotoxic drugs
1. USeful for what pts?
2. What is looked at?
1. Useful in evaluating patients with a low likelihood of significant disease
2. IV contrast given and images of the coronary arteries are obtained
EBCT (Electron beam CT)
1. Quanitifies what?
2. What does it not do?
1. Quantifies coronary artery calcification
1. Does not determine the degree of stenosis
What is Coronary calcification is highly correlated with?
Coronary calcification is highly correlated with atherosclerotic plaques
1. Cardiac MRI uses what kind of contrast media?
2. Perfusion images post __________ stress can be obtained
Still in the early stages of the technology
Dobutamine or adenosine