Atherosclerosis - the system damage of arteries of large and average caliber which is followed by accumulation of lipids, growth of fibrous fibers, dysfunction an endoteliya of a vascular wall and leading to local and general disorders of haemo dynamics. Atherosclerosis can be a patomorfologichesky basis of IBS, the ischemic stroke obliterating damages of the lower extremities, chronic occlusion of mezenterialny vessels, etc. The diagnostic algorithm includes determination of level of lipids of blood, performance of ultrasonography of heart and vessels, angiographic researches. At atherosclerosis medicamentous therapy, a dietotherapy, if necessary - revaskulyariziruyushchy surgical interventions is carried out.
Atherosclerosis – the damage of arteries which is followed by cholesteric deposits in internal covers of vessels, narrowing of their gleam and violation of food of krovosnabzhayemy body. Atherosclerosis of vessels of heart is shown mainly by stenocardia attacks. Leads to development of the coronary heart disease (CHD), myocardial infarction, a cardiosclerosis, aneurism of vessels. Atherosclerosis can lead to an invalidization and premature death.
At atherosclerosis there is a damage of arteries of average and large caliber, elastichesky (large arteries, an aorta) and musculo (mixed: sleepy, arteries of a brain and heart) types. Therefore atherosclerosis is the most frequent reason of a myocardial infarction, IBS, a brain stroke, violations of blood circulation of the lower extremities, a belly aorta, mezenterialny and renal arteries.
In recent years incidence of atherosclerosis assumed the menacing scale, having outstripped such reasons as injuries, infectious and oncological diseases on risk of development of loss of working capacity, an invalidization and mortality. With the largest frequency atherosclerosis affects men 45-50 years are more senior (by 3-4 times more often than women), but occurs at patients of younger age.
Mechanism of development of atherosclerosis
At atherosclerosis system damage of arteries results from violations of lipidic and proteinaceous exchange in walls of vessels. Violations of exchange are characterized by change of a ratio between cholesterol, phospholipids and proteins, and also excess formation of β-lipoproteid.
It is considered that atherosclerosis passes several stages in the development:
The I stage – lipidic (or fatty) spots. For adjournment of fats in a vascular wall an essential role is played by microdamages of walls of arteries and local delay of a blood-groove. Sites of branchings of vessels are most subject to an aterosklerozirovaniye. The vascular wall is loosened and swells. Enzymes of an arterial wall seek to dissolve lipids and to protect its integrity. When protective mechanisms are exhausted, on these sites the difficult complexes of connections consisting of lipids (mainly cholesterol), proteins are formed and there is their adjournment in intim (an internal cover) of arteries. Duration of a stage of a lipidic spot is various. Such fatty spots are seen only under a microscope, they can be found even in babies.
The II stage – a liposkleroza. It is characterized by growth in sites of fatty deposits of young connecting fabric. Gradually there is a formation atherosclerotic (or ateromatozny) the plaque consisting of fats and soyedinitelnotkanny fibers. At this stage atherosclerotic plaques still liquid can be also subjected to dissolution. On the other hand, they constitute danger since their friable surface can be broken off, and fragments of plaques – to cork a gleam of arteries. The vessel wall in the place of an attachment of an ateromatozny plaque loses the elasticity, bursts and izjyazvlyatsya, leading to formation of the blood clots which are also a source of potential danger.
The III stage – an aterokaltsinoza. Further formation of a plaque is connected with its consolidation and adjournment of calcium salts in it. The atherosclerotic plaque can behave steadily or gradually grow, deforming and narrowing an artery gleam, causing the progressing chronic violation of the blood supply fed by the affected artery of body. At the same time the probability of sharp obstruction (occlusion) of a gleam of a vessel blood clot or fragments of the broken-up atherosclerotic plaque with development of the site of a heart attack (necrosis) or gangrene in krovosnabzhayemy an artery of an extremity or body is high.
This point of view on the mechanism of development of atherosclerosis is not only. There are opinions that in development of atherosclerosis infectious agents (a virus of simple herpes, a cytomegalovirus, a chlamydial infection, etc.), the hereditary diseases which are followed by increase in level of cholesterol, mutation of cells of vascular walls etc. play a role.
Factors of development of atherosclerosis
The factors influencing development of atherosclerosis are divided into three groups: ineradicable, removable and potentially removable.
Those which cannot be excluded by means of strong-willed or medical influence belong to ineradicable factors. Enter their number:
- Age. With age the risk of development of atherosclerosis increases. Atherosclerotic changes of vessels are to some extent observed at all people after 40-50 years.
- Floor. At men development of atherosclerosis happens for ten years earlier and exceeds an indicator of incidence of atherosclerosis among women by 4 times. After 50-55 years the incidence of atherosclerosis among women and men is leveled. It is explained by decrease in production of estrogen and their protective function at women in the period of a menopause.
- The burdened family heredity. Quite often atherosclerosis develops at patients whose relatives have this disease. It is proved that heredity on atherosclerosis promotes early (up to 50 years) to development of a disease while after 50 years genetic factors do not render the leading role in its development.
Those which can be excluded by the person by means of change of a habitual way of life are considered as removable factors of atherosclerosis. Treat them:
- Smoking. Its influence on development of atherosclerosis is explained by negative impact of nicotine and pitches on vessels. Long-term smoking several times increases risk of a giperlipidemiya, arterial hypertension, IBS.
- Unbalanced food. Consumption of a large amount of fats of an animal origin accelerates development of atherosclerotic changes of vessels.
- Hypodynamia. Maintaining an inactive way of life promotes violation of fatty exchange and development of obesity, diabetes, atherosclerosis of vessels.
Refer those chronic violations and diseases which are possible for correcting by means of the appointed treatment to potentially and partially removable risk factors. They include:
- Arterial hypertension. Against the background of the increased arterial pressure conditions for the increased treatment of a vascular wall are created by fats that promotes formation of an atherosclerotic plaque. On the other hand, decrease in elasticity of arteries at atherosclerosis promotes maintenance of the increased blood pressure.
- To Dislipidemy. The violation of fatty exchange in an organism which is shown the increased content of cholesterol, triglycerides and lipoproteid plays the leading role in development of atherosclerosis.
- Obesity and diabetes. Increase probability of atherosclerosis by 5-7 times. It is explained by violation of the fatty exchange which is the cornerstone of these diseases and being the trigger of atherosclerotic defeat of vessels.
- Infections and intoxications. Infectious and toxic agents make the damaging impact on vascular walls, promoting their atherosclerotic changes.
Knowledge of the factors promoting development of atherosclerosis is especially important for its prevention since influence of removable and potentially removable circumstances can be weakened or to exclude absolutely. Elimination of adverse factors allows to slow down and facilitate development of atherosclerosis significantly.
At atherosclerosis chest and belly departments of an aorta, coronary, mezenterialny, kidney vessels, and also arteries of the lower extremities and a brain suffer more often. In development of atherosclerosis distinguish the preclinical (asymptomatic) and clinical periods. In the asymptomatic period in blood the increased maintenance of β-lipoproteid or cholesterol in the absence of disease symptoms is found. Clinically atherosclerosis begins to prove when there is a narrowing of an arterial gleam for 50% and more. During the clinical period allocate three stages: ischemic, trombonekrotichesky and fibrous.
Insufficiency of blood supply of this or that body develops in stages of ischemia (for example, myocardium ischemia owing to atherosclerosis of coronary vessels is shown by stenocardia). In a trombonekrotichesky stage thrombosis of the changed arteries joins (so, the course of atherosclerosis of coronary vessels can be complicated by a myocardial infarction). At a stage of fibrous changes there is a growth of connecting fabric in badly krovosnabzhayemy bodies (so, atherosclerosis of coronary arteries leads to development of an atherosclerotic cardiosclerosis).
Clinical symptoms of atherosclerosis depend on a type of the affected arteries. As display of atherosclerosis of coronary vessels serve the stenocardia, a myocardial infarction and a cardiosclerosis which are consistently reflecting stages of insufficiency of blood circulation of heart.
The course of atherosclerosis of an aorta long and long time asymptomatic, even in severe forms. Clinically atherosclerosis of a chest aorta is shown by an aortalgiya – the pressing or burning pains behind a breast irradiating in hands, a back, a neck, stomach top. Unlike pains at stenocardia the aortalgiya can last till several hours and days, periodically weakening or amplifying. Decrease in elasticity of walls of an aorta causes strengthening of work of heart, leading to a hypertrophy of a myocardium of the left ventricle.
Atherosclerotic damage of a belly aorta is shown by pains in a stomach of various localization, a meteorizm, locks. At atherosclerosis of bifurcation of a belly aorta the sleep and a cold snap of legs, hypostasis and hyperaemia of feet, necroses and ulcers of toes, the alternating lameness is observed.
As displays of atherosclerosis of mezenterialny arteries serve attacks of "a belly toad" and violation of digestive function owing to insufficiency of blood supply of intestines. At patients emergence of sharp pains later after food is noted several hours. Pains are localized in a navel or the top departments of a stomach. Duration of a painful attack of several minutes till 1-3 o'clock, sometimes a pain syndrome is stopped by nitroglycerine reception. There are an abdominal distension, an eructation, a lock, heartbeat, increase in arterial pressure. Later fetid ponosa with fragments of undigested food and undigested fat join.
Atherosclerosis of renal arteries leads to development of vazorenalny symptomatic arterial hypertension. In urine erythrocytes, protein, cylinders are defined. At unilateral atherosclerotic damage of arteries the slow progressing of a hypertension which is followed by permanent changes in urine is noted and it is permanent in high figures HELL. Bilateral damage of renal arteries causes a malignant arterial hypertension.
At atherosclerosis of vessels of a brain decrease in memory, intellectual and physical working capacity, attention, intelligence, dizziness, sleep disorders is noted. In cases of the expressed atherosclerosis of vessels of a brain the behavior and mentality of the patient changes. Atherosclerosis of arteries of a brain can be complicated by sharp violation of brain blood circulation, thromboses, hemorrhages.
As displays of the obliterating atherosclerosis of arteries of the lower extremities serve weakness and pains in gastrocnemius muscles of a shin, a sleep and a chill of legs. Development of a syndrome of "the alternating lameness" is characteristic (gastrocnemius muscle pains arise when walking and abate at rest). The cold snap, pallor of extremities, trophic violations (a peeling and dryness of skin, development of trophic ulcers and dry gangrene) are noted.
Serve as complications of atherosclerosis chronic or sharp vascular insufficiency of krovosnabzhayemy body. Development of chronic vascular insufficiency is connected with gradual narrowing (stenosis) of a gleam of an artery atherosclerotic changes – stenoziruyushchy atherosclerosis. Chronic insufficiency of blood supply of body or its part leads to ischemia, a hypoxia, dystrophic and atrophic changes, growth of connecting fabric and development of a melkoochagovy sclerosis.
Sharp obstruction of vessels blood clot or emboly leads to emergence of sharp vascular insufficiency that is shown by clinic of sharp ischemia and heart attack of bodies. In some cases there can be a rupture of aneurism of an artery to a lethal outcome.
Diagnosis of atherosclerosis
Initial data for atherosclerosis are established by clarification of complaints of the patient and risk factors. Consultation of the cardiologist is recommended. At the general survey signs of atherosclerotic defeat of vessels of internals come to light: hypostases, trophic violations, weight reduction, multiple fatty tumors on a body, etc. Auskultation of vessels of heart, aorta reveals systolic noise. For atherosclerosis change of a pulsation of arteries, increase HELL etc. testify.
Data of laboratory researches indicate the increased level of cholesterol of blood, lipoproteid of low density, triglycerides. Radiological on an aortografiya symptoms of atherosclerosis of an aorta come to light: its lengthening, consolidation, , expansion in belly or chest departments, existence of aneurisms. The condition of coronary arteries is defined by carrying out coronary angiography.
Violations of a blood-groove is determined by other arteries by carrying out an angiography – a contrast X-ray analysis of vessels. At atherosclerosis of arteries of the lower extremities according to an angiography their obliteration is registered. By means of UZDG of vessels of kidneys atherosclerosis of renal arteries and corresponding dysfunction of kidneys comes to light.
Methods of ultrasonic diagnostics of arteries of heart, the lower extremities, aortas, carotids register decrease in the main blood-groove on them, existence of ateromatozny plaques and blood clots in gleams of vessels. Decrease in a blood-groove can be diagnosed by means of a reovazografiya of the lower extremities.
Treatment of atherosclerosis
At treatment of atherosclerosis adhere to the following principles:
- restriction of the cholesterol coming to an organism and reduction of its synthesis with cells of fabrics;
- strengthening of removal of cholesterol and its metabolites from an organism;
- use of replacement therapy by estrogen at women in a menopause;
- influence on infectious activators.
Restriction of the cholesterol arriving with food is made by purpose of the diet excluding holesterinsoderzhashchy products.
For drug treatment of atherosclerosis use the following groups of medicines:
- Nicotinic acid and its derivatives – effectively reduce the content of triglycerides and cholesterol in blood, increase the maintenance of the lipoproteid of high density having anti-atherogenous properties. Purpose of medicines of nicotinic acid is contraindicated to the patients having liver diseases.
- Fibrata () - reduce synthesis in an organism of own fats. Also can cause violations in work of a liver and development of cholelithiasis.
- Sekvestranta of bilious acids (, ) – connect and bring bilious acids out of intestines, lowering thereby amount of fats and cholesterol in cages. At their application locks and a meteorizm can be noted.
- Medicines of group of statin (, , ) – are most effective for decrease in cholesterol since they reduce its production in the organism. Apply statins for the night since at night synthesis of cholesterol amplifies. Can lead to violations in work of a liver.
Performing surgical treatment at atherosclerosis is shown in cases of high threat or development of occlusion of an artery by a plaque or blood clot. On arteries both open operations (endarterektomiya), and endovascular - with artery dilatation by means of balloon catheters and installation of a stent in the place of the narrowing of an artery interfering obstruction of a vessel are carried out.
At the expressed atherosclerosis of vessels of heart menacing with development of a myocardial infarction perform operation of aortocoronary shunting.
Forecast and prevention of atherosclerosis
In many respects the forecast of atherosclerosis is defined by behavior and a way of life of the patient. Elimination of possible risk factors and active medicamentous therapy allow to detain development of atherosclerosis and to achieve improvement in a condition of the patient. At development of sharp disorders of blood circulation with formation of the centers of a necrosis in bodies the forecast worsens.
On purpose the prevention of atherosclerosis the refusal of smoking, an exception of a stressful factor, transition to food low-fat and poor in cholesterol is necessary, systematic physical activity it is proportional to opportunities and age, normalization of weight. Inclusion in a diet of the products containing cellulose, vegetable fats (linen and olive oils) dissolving cholesteric deposits is expedient. Progressing of atherosclerosis can be slowed down reception of holesterinsnizhayushchy medicines.