Definition
Hardening of arteries brought by lesions known as atherosclerotic plaques, or atheromas.
- Generally, atheromas are nodules containing gruel, fatty, wax-like substance
- Composed of a soft, necrotic, lipid core (mainly cholesterol and cholesterol esters)
- Covered by a fibrous cap
- As the plaques enlarge, they obstruct the vessel (stenosis) and change the flow hemodynamics
- The change in flow increases the shear stress, which often causes the rupture of the plaque
- Plaque fate is discussed in detail below
- Atherosclerosis common occurs in the coronary arteries and is responsible for the majority of myocardial infarctions
Risk factors
Atherosclerosis is a complex, multifactorial chronic condition with many known risk factors. We can classify them into modifiable (factors under our influence) and non-modifiable factors:
- Modifiable
- Hyperlipidemia and hypercholesterolemia
- Increased levels of LDL and decreased levels of HDL
- LDL mobilizes lipids from the liver to the periphery ("bad cholesterol")
- HDL mobilizes lipids from the periphery to the liver ("good cholesterol")
- Increased levels of LDL and decreased levels of HDL
- Hypertension
- Cigarette smoking
- Diabetes Mellitus
- Associated with hypercholesterolemia
- The cytological metabolic changes provide a favorable environment for the formation of atherosclerosis
- Metabolic
- Hyperlipidemia and hypercholesterolemia