Acute Coronary Syndromes Flashcards
Cardiovascular disease (CVD) includes
- coronary heart disease
- heart failure
- hypertension
- stroke
What is the leading cause of death in the United States?
CVD
Approximately 50% of all CVD deaths are from
CHD
Every 42 seconds in the US
someone suffers a heart attack
Avg age of first MI for men
65
Avg age of first MI for women
72
Why is the age of MI later for women than for men?
estrogen is cardioprotective and women have more estrogen
added benefits of protection only lasts until menopause when estrogen starts to plummet
Acute coronary syndromes include
- Unstable angina pectoris
- Acute myocardial infarction
- Potentially sudden cardiac death
Unstable angina pectoris (chest pain) is the result of
ischemia (decreased blood flow/oxygen)
random, no rhyme or reason, occurs at rest or with exertion. more dangerous
Acute MI
death of cardiac muscle cells due to prolonged ischemia
tissue undergoes necrosis. cannot be regenerated
Endothelium protects against…
innermost layer of artery
atherothrombosis
Intima
thin layer of connective tissue on top of endothelium
What is the formation site of atherosclerotic lesions?
intima
they don’t form at endothelium
Media
located on top of intima; contains mainly smooth muscle cells along with some connective tissue
Adventitia
outermost layer;
contains connective tissue, fibroblasts, and a few smooth muscle cells
Lumen
opening of the vessel
What happens when the endothelium gets damaged?
endothelium is very thin, when it gets damaged, the layer is wiped away from the inner part of the vessel. What is left remaining is the intima. When intima is exposed, cells catch on and plaque starts to form
Atherogenesis
formation of plaque
Atherogenesis:
Endothelial injury
everyone has endothelial injury, but for most it is not chronic or excessive
Chronic or excessive injury
Atherogenesis:
Inflammatory response
after endothelial injury
immune response leads to inflammation
- product of chronic injury
- platelet formation into a cluster
- monocyte (immune cell) accumulation
- LDL-C accumulation (LDL-C platelet response for patching)
these build up on top of one another
Atherogenesis:
Endothelial dysfunction
- product of chronic injury
- increased adhesiveness of platelets and monocytes to artery wall
- increased permeability to lipoproteins in the blood
- impaired vasodilation/ increased vasospasm
lose ability to contract and expand… location of injury cannot function like normal vessel
Atherogenesis:
Plaque formation
- growth factors from platelets exacerbate growth and proliferation of plaque
- lesion progresses from intima to other layers and leads to eventual narrowing of lumen
- firm, pale gray plaque with a fibrous cap
- cap breaks off and leads to free-floating inflammation… can lead to a stroke
Progression of atherogenesis
smaller plaques = less stable and more likely to break off
newer formations = less stable
Plaque rupture or fissuring of the fibrous cap is a risk for
embolus
