Cardiovascular Anesthesia Pt. 1 (Exam III) Flashcards
What are some risk factors for CAD?
- Male
- Age
- ↑ cholesterol
- HTN
- Smoking
- DM
- Obesity
- Sedentary lifestyle
- Genetics
- Personality/Stress
Angina is an imbalance between myocardial _____ and ______.
demand & supply
What is the pain pathway of angina?
Partially occluded coronary artery
→ Adenosine, bradykinin, lactic acid release
→ nociceptive receptors w/ afferent neurons to upper five thoracic sympathetic ganglia
→ thalamic & cortical stimulation = pain
Which spinal levels are responsible for myocardial pain receptors?
Thoracic 1 - 5
What are the two types of angina?
- Chronic (stable) angina = no change in pain intensity or duration over 2 months
- Unstable = pain at rest or increasing in severity/frequency
What two EKG changes are often indicative of subendocardial ischemia?
- ST segment depression
- Transient T-wave depression
What is the name of the point where the transition from the QRS to the ST-segment occurs?
J-Point
What are the three types of ST-Segment depression?
- Up-sloping
- Down-sloping
- Horizontal
What type of ST-segment depression is most likely to be related to coronary disease?
Horizontal ST depression
More ST depression = ______ likelihood of significant CAD.
higher
What diagnostic test assesses coronary perfusion and has greater sensitivity for ischemia than exercise testing?
Nuclear stress test
Which tracers are used with nuclear stress testing?
Thallium & Technetium
What would an absent uptake of nuclear stress test tracers indicate?
Old MI (fibrous tissue)
What would an significant uptake of nuclear stress test tracers indicate?
normal circulation
What would a decreased uptake of nuclear stress test tracers indicate?
Perfusion abnormality
How is non-exercise nuclear stress testing done?
Induced tachycardia w/
- Atropine
- Dobutamine
- Pacing
Which two drugs are coronary dilators used in nuclear stress testing?
Adenosine
Dipyridamole
What type of coronary plaque is considered unstable?
Large lipid core with thin cover
Very likely to rupture.
What does aspirin inhibit?
COX-1
Thromboxane A2
How long does the effect of platelet inhibition due to aspirin last?
For the life of the platelet (irreversible)
What is the “lifespan” of a human platelet?
7 - 10 days
How does Clopidogrel (Plavix) work?
Inhibition of ADP receptor (P2Y12)
What drug class can greatly change the effects of Plavix due to enzyme inhibition?
PPI’s
What drug is similar to clopidogrel in the following:
- Requires P450 enzyme for conversion from prodrug to active metabolite
- Inhibits ADP P2Y12
Prasugrel (Effient)
What are the pros & cons of Prasugrel vs Plavix?
Prasugrel Pros:
- Rapidly absorbed
- Faster onset
- Less individual variability
Cons:
- Higher risk of bleeding (much more potent)
What two conditions were mentioned in lecture as contraindications for nitrate administration?
- Hypertrophic Cardiomyopathy
- Aortic Stenosis
Nitrates have a synergistic effect with what drug classes?
β blockers & CCB’s
What are the effects of nitrates?
- Subendocardial artery dilation
- ↓ SVR
- ↓ afterload
- ↓ myocardial O₂ consumption
Which two cardiac disease processes necessitate a maintenance of a high afterload?
- Hypertrophic Cardiomyopathy
- Aortic Stenosis
Can nitrates be given around the clock?
No, 8 - 12 hours of the day need to be nitrate free.
Sensitization occurs w/ around the clock therapy.