Flashcards in Coronary Artery Disease Deck (76)
How does CAD occur?
Results from atherosclerotic process, a disease of endothelial dysfunction that is chronic, systemic, and inflammatory.
Cholesterol deposits onto intima / endothelial layer and plague protrudes into coronary artery.
Which layer of the blood vessel does plaque attach to?
Intima / Endothelial
What is Acute Coronary Syndrome?
Acute episode of chest pain unrelieved by rest or reversal of precipitating factor or nitroglycerin.
What is the patho of ACS?
1) Plaque ruptures in coronary artery
2) Damaged area releases plaque contents and attracts platelets
3) Platelets adhere to area and become activated (platelet aggregation)
4) Fibrin deposits stabilize the thrombus
5) Abrupt decrease in coronary artery blood flow
6) Imbalance between myocardial O2 demand and supply leads to injury, ischemia, necrosis
What is angina?
Temporary chest pain associated with CA blockage or arterial spasm
What are the two types of ischemia?
1) Demand ischemia --> Increased O2 demand of cardiac muscle
2) Supply ischemia --> Structural or functional issues in CA leading to decreased blood flow and perfusion
What is stable angina?
Caused by known precipitating factors, controlled by rest, reversal of cause
What is pinzmetal angina?
Spasm of CA causing supply problem decreasing blood flow. Can lead to angina or arrythmia (most commonly V-fib), CAD may or may not be present
What is unstable angina?
Caused by plaque instability, rupture, and thrombus formation.
Causes INCOMPLETE CA occlusion. Can be a change from stable angina or occur suddenly, unable to be relieved
What are the goals of treatment for angina?
1) Increase myocardial O2 supply
2) Decrease myocardial O2 demand
3) Prevent MI
4) Intervene if unstable
What interventions can increase myocardial O2 supply?
O2, nitrates, Ca channel blockers to vasodilate
What interventions can decrease myocardial O2 demand?
Beta blockers, ACE inhibitors, analgesia
What interventions can prevent MI?
Platelet inhibitors, anticoagulants, antihypertensives, cholesterol lowering agents
What interventions if unstable angina?
PCI, IABP, CABG
What are the zones of injury for myocardial infarction?
1) Zone of ischemia
2) Zone of injury
3) Zone of necrosis
What is the zone of ischemia in MI?
Outer layer of infarcted myocardium, cells deprived of O2.
T wave inversion due to impaired repolarization, ST depression
Goal to increase O2 supply
What is the zone of injury in MI?
Area surrounding the infarcted area, cells are injured and may die
ST elevation with T wave inversion due to incomplete cell repolarization
Goal to stop progression to necrosis
What is the zone of necrosis in MI?
Dead tissue does not respond electrically or mechanically
Infarcted tissue eventually replaced with scar tissue
Pathological Q waves seen after 24 hrs from non-responsive cells
What is the effect of MI on CO?
Increase HR to compensate for low BP, preload stays high d/t decrease in FOC there is compensatory vasoconstriction which increases afterload
What is STEMI?
Irreversible cell death through all 3 layers of the heart.
ST elevation, pathological q waves, new LBB seen
Tissue death begins 30-45 mins up to 6 hrs
What is NSTEMI?
Irreversible cell death does not reach full thickness of myocardium (PARTIAL OCCLUSION)
ST depression, prominent T wave inversion, troponins elevated
Occlusion of RCA affects what area?
R atria, R ventricle, AV and SA node, inferior area of heart
Occlusions result in bradycardias, heart blocks, RV failure
Occlusion of L main coronary artery affects what area?
Anterior, lateral wall of LV. Can result in LV failed
Occlusion of the LAD affects what area?
Anterior LV, septum, bundle branches
Occlusions result in LV failure and conduction issues
Occlusion of the circumflex artery affects what area?
Lateral, posterior LV
Occlusions result in L free wall damage, aneurysm
What CA supplies the anterior area of the heart?
What CA supplies to septal area of the heart?
What CA supplies the lateral area of the heart?
What CA supplies the inferior area of the heart?