Atherosclerosis
(also known as arteriosclerotic vascular disease or ASVD) is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol and triglyceride.
It is a syndrome affecting arterial blood vessels, a chronic inflammatory response in the walls of arteries, caused largely by the accumulation of macrophages and white blood cells and promoted by low-density lipoproteins (LDL, plasma proteins that carry cholesterol and triglycerides) without adequate removal of fats and cholesterol from the macrophages by functional high-density lipoproteins (HDL) (see apoA-1 Milano). It is commonly referred to as a hardening or furring of the arteries. It is caused by the formation of multiple plaques within the arteries.[1]
The atheromatous plaque is divided into three distinct components:
- The atheroma ("lump of gruel", from Greek ἀθήρα (athera), meaning "gruel"), which is the nodular accumulation of a soft, flaky, yellowish material at the center of large plaques, composed of macrophages nearest the lumen of the artery
- Underlying areas of cholesterol crystals
- Calcification at the outer base of older/more advanced lesions.
The same process in an artery to the brain is commonly called stroke. Another common scenario in very advanced disease is claudication from insufficient blood supply to the legs, typically caused by a combination of both stenosis and aneurysmal segments narrowed with clots.
Atherosclerosis affects the entire artery tree, but mostly larger, high-pressure vessels such as the coronary, renal, femoral, cerebral, and carotid arteries. These are termed "clinically silent" because the person having the infarction does not notice the problem and does not seek medical help, or when they do, physicians do not recognize what has happened.
Clinically, atherosclerosis is typically associated with men over the age of 45. Sub-clinically, the disease begins to appear at early childhood, and perhaps even at birth. Noticeable signs can begin developing at puberty. Though symptoms are rarely exhibited in children, early screening of children for cardiovascular diseases could be beneficial to both the child and his/her relatives.[6] Atheroma in arm, or more often in leg arteries, which produces decreased blood flow is called peripheral artery occlusive disease (PAOD). Typically, atherosclerosis begins as a thin layer of white streaks on the artery wall (usually due to white blood cells) and progresses from there. While coronary artery disease is more prevalent in men than women, atherosclerosis of the cerebral arteries and strokes equally affect both sexes.
According to United States data for the year 2004, for about 66% of men and 47% of women, the first symptom of atherosclerotic cardiovascular disease is heart attack or sudden cardiac death (death within one hour of onset of the symptom).[citation need
Most artery flow disrupting events occur at locations with less than 50% lumen narrowing (~20% stenosis is average). The illustration above, like most illustrations of arterial disease, overemphasizes lumen narrowing, as opposed to compensatory external diameter enlargement (at least within smaller arteries, e.g., heart arteries) typical of the atherosclerosis process as it progresses (see Glagov[7] or the ASTEROID trial[8]).
Source : wikipedia
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