Step Up - Diseases Of The Cardiovascular System Flashcards
In a patient with CAD, goal of LDL is:
Less than 100mg/dL
Ischemic pain - What should be noted especially?
- Does NOT change with breathing nor with body position.
2. Patients do NOT have chest wall tenderness.
Two conditions termed syndrome X:
- Metabolic syndrome X
2. Syndrome X
Syndrome X?
- Exertional angina with NORMAL coronary arteriogram - Patients present with chest pain after exertion but have no coronary stenoses at cardiac catheterization.
- Exercise testing and nuclear imaging show evidence of myocardial ischemia.
- Prognosis is excellent.
Diagnosis of CAD - Physical exam?
Most of the times –> normal.
Best initial test for all forms of chest pain?
ECG
Diagnosis of CAD - Resting ECG:
- Usually normal in patients with stable angina.
- Q waves are consistent with a prior myocardial infarction.
- If ST segment or T wave abnormalities are present during an episode of chest pain, then treat as for unstable angina.
Diagnosis of CAD - Stress test - Features?
- Useful for patients with an intermediate pretest probability of CAD based upon age, gender, symptoms.
- For patients with normal resting ECG, determine whether the patient is capable of performing treadmill exercise.
- If so, proceed to an exercise stress test.
Stress ECG - Use where?
- To confirm diagnosis of angina
- To evaluate response of therapy in patients with documented CAD.
- To identify patients with CAD who may have a high risk of acute coronary events.
Stress ECG - Features?
- Recording ECG before, during, and after exercise on a treadmill.
- 75% sensitive if patients are able to exercise sufficiently to increase HR to 85% of max predicted value for age.
How do we calculate a person’s max HR?
By substracting age from 220 (220-age).
Stress ECG - Detection of ischemia is based on?
ST depression –> Exercise-induced ischemia results in subendocardial ischemia, producing ST segment depression.
Stress ECG - Other findings besides ST depression?
- Onset of HF
- Ventricular arrhythmia during exercise
- Hypotension
Patients with a positive stress test should undergo what?
Cardiac catheterization
To sum up - A stress test is considered positive, if the patient develops any of the following during exercise:
- ST depression
- Chest pain
- Hypotension
- Significant arrhythmias
Stress Echocardiography - When to perform?
Performed before and immediately after exercise.
–> Exercise-induced ischemia is evidenced by wall motion abnormalities (eg akinesis, dyskinesis) not present at rest.
Stress Echo - Better than stress ECG?
- Favored by many cardiologists over stress ECG.
- More sensitive in detecting ischemia.
- Can assess LV size and function.
- Can diagnose valvular disease.
- Can be used to identify CAD.
Patients with a positive stress Echo should undergo?
Cardiac catheterization.
To sum up - Types of stress tests:
- Exercise tolerance test –> ST-segment depression.
- Exercise or dobutamine echo –> Wall motion abnormalities
- Exercise or dipyridamole thallium –> Decr. uptake of the isotope during exercise.
Thallium - What happens with viable myocardial cells?
Viable myocardial cells extract the isotope from the blood - No isotope uptake means no blood flow to an area of the myocardium.
–> Important for… REPERFUSION!
Thallium perfusion imaging - Pros and cons?
- Incr. the sensitivity/specificity of exercise stress test.
- More expensive.
- Subjects patient to radiation.
- It is not helpful in the presence of a LBBB.
If the patient cannot exercise - Perform what?
A pharmacologic stress test.
Pharmacologic stress test - How to perform?
- IV adenosine
- Dipyridamole
- Dobutamine
are used.
Combined with: ECG, echo, nuclear perfusion imaging.
IV adenosine and dipyridamole lead to GENERALIZED coronary vasodilation. What is the importance of this?
Since diseased coronary arteries are already MAXIMALLY DILATED at rest to increase blood flow, they receive relatively less blood flow when the entire coronary system is pharmacologically vasodilated.
Holter monitoring (ambulatory ECG) - useful in what?
- Detecting silent ischemia.
- Arrhythmias
- HR variability
- Assess pacemaker and implantable cardioverter-defibrillator (ICD) function.
- Useful in evaluating unexplained syncope and dizziness as well.
What is the definitive test for CAD?
Coronary angiography
Coronary angiography is often performed together with?
PCI or for patients being considered for revascularization with CABG.
What happens if coronary angiography is severe?
CABG - for Left main or 3-vessel disease.
Cardiac catheterization - Features?
- Most accurate method of determining a specific cardiac diagnosis.
- Provides info on hemodynamics, intracranial pressure measurements, CO, SaO2.
Indications for cardiac catheterization?
Generally performed when revascularization or other surgical interventions are considered.
- Positive stress test
- Angina + Non invasive tests are nondiagnostic/angina despite medical therapy/Angina post MI/Angina that is diagnostic dilemma.
- Severely symptomatic patient and urgent diagnosis/management are necessary.
- Evaluation of valvular disease, and to determine the need for surgical intervention.
Coronary angiography - Features?
- Most accurate method of identifying presence and severity of CAD.
- Standard test for delineating coronary anatomy.
Coronary angiography - Purpose?
Main purpose is to identify patients with severe coronary disease to determine whether revascularization is needed. Revascularization with PCI involving a balloon and/or a stent can be performed at the same time as the diagnostic procedure.
Standard of care for stable angina?
Aspirin + Beta blocker (only ones to lower mortality).
+ Nitrates for chest pain.
Side effects of nitrates?
- Headache
- Orthostatic hypotension
- Tolerance
- Syncope
First line beta blockers?
Atenolol and metoprolol.
Routes for nitrates?
- Oral
- Sublingual
- Transdermal
- IV
- In paste form
For chronic angina, oral or transdermal patches are used.
CCB - Mechanism of action?
Cause coronary vasodilation + AFTERLOAD reduction, in addition to reducing contractility.
If CHF is also present - Give what?
ACEIs + Diuretics.
Revascularization - Where is it preferred?
- May be preferred for high risk patients.
- Some controversy whether revascularization is superior to medical management for a patient with stable angina and stenosis >70%.
Revascularization - Methods?
- PCI
2. CABG
Revascularization - does it reduce the incidence of MI?
NO - But does result in significant improvement of symptoms.
General guidelines - Management of all patients?
Risk factor modification + Aspirin.
General guidelines - Mild disease (normal EF, mild angina, single vessel disease):
- Nitrates
- Beta blocker
- Consider CCBs if symptoms continue.
General guidelines - Moderate disease (normal EF, moderate angina, two-vessel disease):
If the above regimen does not control symptoms –> Coronary angiography to assess suitability for revascularization (either PCI or CABG).
General guidelines - Severe disease (Decreased EF, severe angina, 3 vessel/left main or LAD disease):
Coronary angiography and consider for CABG.
PCI - What is it?
Consists of both coronary angioplasty with a balloon and stenting.
PCI - Should be considered in?
- Patients with one-, two-, three-vessel disease.
2. Best used if proximal lesions.
PCI - Significant problem?
Restenosis –> Up to 40% within the first 6 months.