Athérome

Athérosclérose and arteriosclerosis

In a general way, the term “sclerosis” indicates all fibrous Dégénérescence of a fabric or a Organe. With the age, the fabrics which constitute the Artère S lose their elasticity and become more rigid. The normal ageing of the arteries names arteriosclerosis .

The athérome comes from the Greek athérê who means “pulp”. It corresponds to a rehandling of the intima (the internal wall) of the Artère S the large one and average gauge (Aorte and its branches, arteries coronary S, cerebral arteries, arteries of the lower extremities) by segmentary accumulation of Lipides, complex Glucides, blood Sang and produced, fat Tissus, layers of sediment and other minerals.

Epidemiology

The athérome is the dominant etiology of the majority of the cardiovascular affections.

It is real public health problems.

  • Pemière causes mortality in the countries occidentalized by coronary Insuffisance, cerebral affections
  • first cause responsible for the diseases and coronary attacks
  • major Cause of disability and morbidity ( Cardiac failure, after-effects of AVC, ischemic accidents transitory (AIT), aortic Artériopathie obliterating lower extremities, aneurisms, impaired renal functions and infarction mesenteric)

Anatomo-pathology

See

  • Structure of a normal Artery

Physiological phenomenon

The athérosclérose begins as of the embryonic life, since it is about a phenomenon Physiologique of Vieillissement of the arteries, but he is considerably accelerated by the Risk factors cardiovascular. Towards the 20 years age of the fine arterial lesions can be observed.

Pathological phenomenon

  • It begin with lipidic infiltrations on the level from the intima (lipidic Stries) involving a thickening from this intima. Then, one witnesses a proliferation of smooth muscular cells and conjunctive Tissu, involving the formation of an inflammatory unstable plate.
  • the plate of athérome consists of a core necrotic (cellular remains, crystals of Cholestérol and Calcium), surrounded by a fibrous layer (smooth muscular cells, spumous cells, cholesterol crystals), with destruction of the limiting blade elastic intern
  • Complications: disorders of the Vasomotricité, Ulceration of the plate of athérome, Thrombosis, rupture of the plate, Aneurism, Embole…

The evolution of the installation of the plate is done in several stages:

1) Initiation: Presence of spumous macrophages (gorged with cholesterol and triglycerides) in the Intima of the artery

2) Lipidic scratch: Presence of extracellular lipidic deposits

3) Plate young person. Constituted slightly before 40 years

4) Plate fibro-lipidic athérome

5) Plate sténosante, calcified. Constituted around 60 years

6) Complicated plate, evolving/moving in sténose with strong risks to transform itself into thrombus

Preferential localizations

  • Reached arteries carotid S (principal risk factor: arterial hypertension)
  • Reached arteries coronary S (principal risk factor: cholesterol)
  • Artériopathie obliterating lower extremities (principal risk factor: tobacco)
  • renal Arteries which can involve a Impaired renal function

Risk factors

Nonmodifiable risk factors

  1. the first risk factor associated with the athérosclérose is the age . The lesions appear as of the fetal life and are finely visible as of 20 years;
  2. Sex . This disease reaches more the male population. The increased presence of estrogens protects the woman until the Ménopause;
  3. Heredity :
*L' family hypercholesterolemy hétérozygote reaches 1 subject on 5000.
*L' family hypercholesterolemy homozygote reaches 1 subject out of 1 million.

Modifiable risk factors

  1. Nicotinism . 1 cause associated with the development with complications related to the athérosclérose;
  2. Cholesterol . An important rate of LDL (bad cholesterol) supports the development of the disease. It should however be noted that a cholesterol low level HDL (<0,4 g/l, good cholesterol, protective factor) is dangerous for the arteries;
  3. arterial Hypertension . Strongly support the formation of the plates of athérome in the arteries carotids. It is a great cause of cerebral vascular accidents (AVC);
  4. Diabetes ;
  5. Sedentariness with the metabolic disorders which accompany it: Obesity;
  6. Salt and alcohol is also risk factors.

See

See also: Risk factors cardiovascular

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