Cardiology\ Coronary Artery Disease Flashcards
Describe the initial pathogenesis of atherosclerosis
- Endothelial injury leads to
- increased leukocyte adhesion to the endothelium
- increased endothelial permeability, and
- endothelial release of hemostatic and vasoactive substances
How is angina pectoris diagnosed?
Clinical history of a retrosternal pressure-like or squeezing sensation, frequently with radiation to the arms, neck, and jaw
Chest pain relief with nitroglycerin is diagnostic for angina. True or false?
False. Nitroglycerin can also decrease pain due to esophageal spasm.
What characterizes chronic stable angina?
Reproducibility with a consistent amount of exertion and long-standing symptoms
How is exercise-induced angina diagnosed?
Stress test results demonstrate ST depression during exercise.
Which stress-test findings may imply a poorer prognosis in cases of chronic stable angina?
- ST depression greater than 2 mm
- ischemia at low stress levels
- hypotension resulting from exertion
- the presence of ischemic changes in more than five ECG leads
What three general management strategies should be considered in chronic stable angina?
- Modification of risk factors
- Symptomatic relief of angina via medication or interventional modalities
- Treatment of other contributing diseases
What other diseases may exacerbate chronic stable angina?
- Fever
- anemia
- congestive heart failure
- infection
- thyrotoxicosis
What medications may provide symptomatic relief of angina?
- Nitrates
- calcium channel blockers
- beta-blockers
Describe the mechanism by which nitrates provide symptomatic relief.
Vasodilation of the following:
- Coronary vessels → increase myocardial oxygen supply
- Peripheral veins → decrease venous return to the heart → preload reduction → decrease in myocardial oxygen demand
- Peripheral arteries → decrease in peripheral vascular resistance → afterload reduction → decrease in myocardial oxygen demand
Do nitrates have a predominant effect on veins or arteries?
Veins (and therefore preload)
Describe the mechanism by which beta-blockers and calcium channel blockers provide symptomatic relief
Decrease myocardial oxygen demand by decreasingheart rate (HR), blood pressure (BP), and contractility
If angina continues despite maximal medical management, what strategies may be employed?
- Cardiac catheterization to evaluate coronary anatomy
- revascularisation can e considered via coronary angioplasty, stenting or CABG
Describe Prinzmetal variant angina
Angina at rest characterized by transient coronary artery spasm and ST elevation
What conditions fall under the heading of acute coronary syndromes (ACS)?
- Unstable angina (UA)
- non-ST-elevation myocardial infarction (MI) (NSTEMI)
- ST-elevation MI (STEMI)
What physical exam findings are typical of ACS?
- Tachycardia
- transient S3 or S4
- hypertension
- mitral regurgitation secondary to ischemia of the papillary muscle
Describe UA
- New onset angina (<2 months) with only minimal exertion
- crescendo angina in the setting of existing stable angina
- angina at rest of greater than 20 minutes
- angina occurring greater than 24 hrs post-MI
What ECG findings may be seen in UA?
ST depression or symmetric T-wave inversions
In what percentage of patients does UA progress to MI?
Approximately 5%
In cases of UA, what are the major steps for providing symptomatic relief and preserving myocardial function?
- Provide analgesia
- improve coronary blood flow
- prevent coronary thrombosis
- decrease myocardial oxygen demand
What drug options should be considered to address analgesia?
Morphine to decrease pain and anxiety
Why is it important to control pain in a patient with UA?
Analgesia can decrease the sympathetic response (lower HR and BP), which decreases myocardial oxygen demand.
When should antiplatelet therapy be started?
Immediately after UA is suspected
What drug should be used to provide antiplatelet action acutely?
Aspirin 162-325 mg
