Ischemic Heart Disease (Exam II) Flashcards
What chemical mediators are released from ischemia that activate cardiac nociceptors?
Adenosine and Bradykinin
What is the path for cardiac pain signals to reach the spinal cord?
Cardiac nociceptors → Afferent Neurons → T1 - T5 SNS ganglia.
What is the CNS response to cardiac ischemia?
- ↓ AV conduction and thus ↓HR
- ↓ Contractility
Differentiate stable vs unstable angina.
- Stable - No change in chest pain severity or frequency in 2-mo period.
- Unstable - Increasing frequency and severity of chest pain. (without increase in cardiac biomarkers)
What other systems may cause chest pain not related to IHD?
Cardiac- pericarditis
Vascular- aortic dissection, PE, P HTN
pulmonary- pleuritis, pneumo
GI- GERD, gallbladder, pancreatitis
musculoskeletal- trauma, cervical disk disease
infections- herpes zoster
psychological- panic disorder (hardest to rule out)
How long do troponin levels remain elevated for?
bumps in 3-4 hours, elevated for up to 2 wks
Are cardiac biomarkers (troponin) present with unstable angina?
NO. If they were, that would be an MI.
What EKG abnormality is associated with old MI’s and/or current ischemia?
T-wave inversion
ST segment depression is characteristic of what?
subendocardial ischemia
At least _____ of horizontal or downscoping ___________________ during or within _____ minutes after exercise is indicative of ________
1mm, ST segment depression, 4 minutes, significant CAD
Exercise EKG (stress test) is useful for what?
detecting s/sx of myocardial ischemia
often combined with imaging studies to demonstrate areas of ischemic myocardium
What is nuclear stress testing utilized for?
Coronary Perfusion assessment
Is nuclear stress test or exercise testing more sensitive for detection of IHD?
nuclear stress imaging
What determines the significance of CAD during a nuclear stress test?
Size of the perfusion abnormality
Arrows point to arrows of lesser perfusion.
What test can differentiate a new vs and old perfusion abnormality?
Nuclear Stress Testing
What nuclear stress test tracers are used with exercise?
Tina Turner getting stressed
Thallium and technetium
What nuclear stress test drugs are used without exercise?
Atropine
Dobutamine
Pacing
When are adenosine and dipyridamole used with nuclear stress testing? Why?
Used after test to dilate normal, non-ischemic areas of the heart.
What test would be useful for imaging wall motion abnormalities or valvular function?
Echocardiography
What is Prinzmetal Angina?
Coronary Spasm
What is coronary angiography used for?
Prinz Logan Does Not Armwrestle
determines location of occlusive disease
diagnose prinzmetal angina
assess results of angioplasty/stenting
does NOT measure stability of plaque
What is the treatment for angina pectoris?
cessation of smoking
IBW
low fat, low-cholesterol diet (Statin)
regular aerobic exercise
treatment of HTN
What is the mechanism of action for aspirin?
COX-1 Inhibition → TXA2 inhibition → Plt aggregation inhibition.
What is the function of TXA2?
stimulates activation of new platelets as well as increases platelet aggregation
How can aspirin be reversed?
Trick question. It can’t be, platelets are damaged until they die and are replaced.
What are examples of IIb/IIIa receptor antagonists?
abciximab, eptifibatide, tirofiban
What is the mechanism of action of abciximab, eptifibatide, and tirofiban?
Platelet glycoprotein IIb/IIIa receptor antagonists
Inhibit platelet activation, adhesion, and aggregation.
What drugs (discussed in lecture) are P2Y12 inhibitors?
Clopidogrel and Prasugrel
What common drug class will antagonize P2Y12 inhibitors?
PPIs
How does Prasugrel compare to Clopidogrel?
More predictable pharmacokinetics but greater bleeding risk.
clopidogrel is a ______
prodrug
How do P2Y12 inhibitors work?
Inhibit ADP receptor P2Y12 and thus inhibit platelet aggregation.
What drug classes are synergistic with nitrates?
- β-blockers
- CCBs
When are nitrates contraindicated?
- Aortic Stenosis
- Hypertrophic Cardiomyopathy
What are the consequences of taking a nitrate? (5)
decrease frequency, duration, and severity of angina
dilate coronary arteries and collaterals
decrease SVR
decreases preload
potential anti-thrombotic effects
What drug class is the only one proven to prolong life in CAD patients?
β-blockers
decreases risk of death and reinfarction in MI pt
What properties do β-blockers have? (3)
- Anti-ischemia
- Anti-HTN
- Anti-dysrhythmic
Which β blockers are cardioselective?
- Atenolol
- Metoprolol
- Acebutolol
- Bisoprolol
- “BAMA”
Which β blockers are non-selective?
- Propanolol
- Nadolol
What risk is associated with non-selective β blockers in asthma patients?
↑ risk of bronchospasm in reactive airway disease patients.