arteriosclerosis

arteriosclerosis, general term for a condition characterized by thickening, hardening, and loss of elasticity of the walls of the blood vessels. These changes are frequently accompanied by accumulations inside the vessel walls of lipids, e.g., cholesterol; this condition is frequently referred to as atherosclerosis. Initially lesions are formed on the arterial walls, which results in blistering and the accumulation of low-density cholesterol. This produces higher blood pressure, which facilitates the imbedding of cholesterol and calcium in the vessel walls. The fatty material accumulates calcium and produces hard plaques, thus hardening the walls of the vessels. As the vessel walls thicken, the passageways through the vessels narrow, decreasing the blood supply to the affected region. Constriction of the coronary arteries may affect the heart (see coronary artery disease, heart disease). If the leg vessels are affected, there may be pain with walking and an onset of gangrene. When there is total clotting of a vessel (thrombosis) the result may be a heart attack (if it occurs in the coronary arteries) or stroke (if in cerebral arteries).

Arteriosclerosis risk factors include hypertension, elevated levels of fats in the blood, cigarette smoking, diabetes mellitus, and obesity. Genetic risks are related to the ability of the body to process (uptake and metabolize) low-density lipids that contain cholesterol. Reduction of body cholesterol to normal levels through cholesterol-lowering drugs and a restricted-fat diet is usually prescribed. The latter generally entails substitution of vegetable fats for animal fats, but an exception may be "trans fat," artificially hydrogenated vegetable oils found in margarine and vegetable shortening, which studies have linked to increased risk of coronary disease. Treatment of hypertension, stress management, and cessation of smoking are also important. Increasing consumption of antioxidants and folic acid may be protective. Surgical treatment that bypasses clogged areas or procedures such as angioplasty are sometimes necessary; gene therapy that forces the growth of new blood vessels bypassing an area has also been used. Exercise often can increase utilization of excess low-density lipids. Although the relationship between blood cholesterol levels and arteriosclerosis is not fully understood, the utilization of low-density lipids appears to be a primary indicator of the risk of arteriosclerosis.

or hardening of the arteries

Chronic disease characterized by abnormal thickening of the walls of the arteries due to fatty deposits (atheromas) of cholesterol on the arterial inner walls (seeartery). These thicken, forming plaques that narrow the vessel channel (lumen) and impede blood flow. Scarring and calcification make the walls less elastic, raising blood pressure. Eventually plaques may completely block a lumen, or a blood clot (thrombus) may obstruct a narrowed channel. Atherosclerosis of one or more coronary arteries (also called coronary heart disease) can decrease the heart muscle's blood supply, causing angina pectoris. Complete blockage causes heart attack. In the brain, atherosclerosis may result in stroke. Treatments include drugs that reduce the level of cholesterol and fat in the blood, anticoagulants and other drugs that prevent the formation of blood clots, coronary bypass, and balloon angioplasty.

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Arteriosclerosis refers to a hardening of medium and large arteries. The most common form of arteriosclerosis is atherosclerosis.

Etymology

The following terms are similar, yet distinct, in both spelling and meaning, and can be easily confused: arteriosclerosis, arteriolosclerosis, and atherosclerosis. Arteriosclerosis is a general term describing any hardening (and loss of elasticity) of medium or large arteries (from the Greek Arterio, meaning artery, and sclerosis, meaning hardening), arteriolosclerosis is any hardening (and loss of elasticity) of arterioles (small arteries), atherosclerosis is a hardening of an artery specifically due to an atheromatous plaque. Therefore, atherosclerosis is a form of arteriosclerosis.

Types

• Atherosclerosis is the most common form of arteriosclerosis. Atherosclerosis is characterized by a thickening of the intima with plaques that can contain lipid-laden macrophages ("foam cells"). The plaques contain free lipid (cholesterol, etc.) and are prone to calcification and ulceration.
• Arteriosclerosis obliterans is typically seen in medium and large arteries of the lower extremity. Characterized by fibrosis of the intima and calcification of the media. The lumen of the vessel may be obliterated or markedly narrowed.
• Medial calcific sclerosis (Monckeberg’s calcific sclerosis) is seen mostly in the elderly, commonly in arteries of the thyroid and uterus. Characterized by calcification of the internal elastic lamina but without thickening of the intima or narrowing of the vessel lumen. A similar form of an intramural calcification, presenting the picture of an early phase of arteriosclerosis, appears to be induced by a number of drugs that have an antiproliferative mechanism of action (Rainer Liedtke 2008).
• Hyaline arteriolosclerosis refers to thickening of the walls of arterioles by the deposition of hyaline material. Often seen in kidney pathology.

External links

• Arterial Vascular Effects of Non-steroidal Antiphlogistic Drugs - A Biochemical Model on an Intramural Induction of Arteriosclerosis, Rainer K Liedtke, MD