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Diseases of the blood vessels

Diseases of the blood vessels

Atherosclerosis

by D-r Bojan Danailov, MD


 

The wall of a blood vessel / artery is made up of three layers: intima, media and adventitia.

Intima is the inner lining of the vessel.

Media is the middle, muscular layer and adventitia is the outer layer of the blood vessels.

There are several factors that affect the quality and construction, and thus the function of the vessel. The only changes that cannot be prevented are the changes due to aging, when thickening of the inner layer of the blood vessel (intima) occurs.

Atherosclerosis is the major cause of death for either sex over and under age 65.

Arteriosclerosis is a general term for thickening and hardening of the arterial wall. It is characterized by dysfunction of the endothelium of the vessel, vasculitis, deposition of lipids, cholesterol, calcium and cellular elements within the vessel wall. This process resulted in the formation of plaques, vascular remodeling, acute and chronic obstruction of the lumen and reduced oxygenation of the target tissues (organs nourished by the same blood vessel).

 

Causes of atherosclerosis

Hyperlipidemia (elevated levels of fats in the blood), hypercholesterolaemia, hypertriglyceridaemia.

Diseases and conditions in which increase of blood fats occurs: uncontrolled diabetes, decreased function of the thyroid gland - hypothyroidism, uraemia, obstructive liver damage, dysproteinemia, use of oral contraceptives, glucocorticoids, antihypertensives (thiazide diuretics, beta blockers). Uncontrolled, excessive eating foods high in fat, drinking alcohol, and genetic factors. Cigarette smoking, physical inactivity and stress greatly contribute to the worsening of atherosclerosis. High blood pressure is one of the most common causes of damage to blood vessels, resulting in coronary heart disease and stroke.

Lately, more importance is attributed to C reactive protein, elevated levels of homocysteine ​​and fibrinogen levels, and increased LDL cholesterol fraction.

There is early occurrence of fatty streaks (initial lesions), without occluding the lumen of the vessel, increasing in number until age 20, that progressively enlarge especially at the level of the aorta. In the beginning, they do not affect the blood flow, but lesions are being formed subsequently associated with a clinical illness. 

The latter form is a "complicated lesion", which is a fibrous atheromatous plaque with varying degrees of necrosis, thrombosis and ulceration.

 Atherosclerosis is more common in men than in women, since women during the reproductive period are protected until menopause with sex hormones. However, after menopause, the risk evens. Let also mention that the clinical manifestation of the atherosclerosis is more pronounced between 40 and 70 years of age.

 The clinical disease and the symptoms depend on the organ affected, i.e. on the damaged blood vessels of that organ.

The most common clinical effects of atherosclerosis

- Obstruction of the lumen of the vessel which is asymptomatic until fibrous plaque obstruct between 50 and 70% of the lumen. Then problems occur due to reduced blood supply.

- Plaque rupture or thrombosis

- Occurrence of angina pectoris, stroke (cerebrovascular insult), peripheral vascular illness - limb pain during more or less physical effort, limb infections, impotence, mesenteric angina accompanied by pain in the epigastrium, vomiting blood, diarrhea, loss of electrolytes, appearance of blood in stools and weight loss.

- Aneurysm of the abdominal aorta is usually asymptomatic, but it is also a pronounced, dangerous disease because of the possibility of rupture and bleeding.

 

Localization

Despite the fact that in clinical practice, we use the term `generalized atherosclerosis`, however, there is no rule for predilection site of occurrence of these changes. Lesions are usually scattered throughout the body's blood vessels, in irregular order, depending on age and gender.

Commonly altered blood vessel is the aorta, especially its initial part, and the heart blood vessels, the arch of aorta and the bifurcation of the iliac arteries.

Atherosclerosis is more common in the lower than in the upper extremities. 

There is an irregularity in the occurrence of the atherosclerotic changes of the blood vessels in the brain, but firstly they occur in the carotid, basilar and the vertebral arteries.  

 

Objective signs of the atherosclerosis

Hyperlipidemia - elevated blood fat

Coronary heart disease, fast pulse rate, increased or decreased blood pressure

Cerebrovascular disease - neurological disturbances, reduced carotid pulse rate

Peripheral vascular disease, decreased peripheral pulse rate, peripheral arterial bruits, peripheral cyanosis, gangrene, ulceration.

Abdominal aortic aneurysm - a pulsating mass in the abdomen, peripheral emboli, circulatory collapse

Atheroembolism - gangrene, cyanosis, ulceration.

 

Methods for evidence of atherosclerosis

Laboratory tests / lipid status, echo Doppler echocardiography, coronary stress test, perfusion scintigraphy, angiography / coronarography as the most precise method. 

The reduced physical activity and stress contribute significantly to the deterioration of atherosclerosis.

 

Treatment 

The first and foremost is the prevention of atherosclerosis and its treatment.

Prevention means elimination of all the risk factors that lead to the occurrence of atherosclerosis.

- Regulation of the high blood pressure and its regular control.

- Reduction of the blood lipid levels by reducing the intake of dietary fat and concentrated sugars.

- Treatment of diabetes

- Smoking cessation

The diet is one of the most important ways to reduce the blood lipid levels i.e. eating healthy foods. When the blood lipid levels are within normal range, it is not allowed to eat butter, whole milk and cheese, pork, offal, canned meats, bacon, sausages, avocado, nuts, dried fruits, coconuts, alcohol, chocolate, pastry, chips, crisps, cakes, ice cream, mayonnaise, all juices with added sugar.

Increased physical activity is a very important factor in preventing the progression / worsening of atherosclerosis

The treatment depends on the extent of atherosclerosis.

Drugs used in medical practice

HMG-CoA reductase inhibitors, which act on the reduction of cholesterol and triglyceride levels

Fibrates act by lowering triglyceride and LDL cholesterol levels. 

Antioxidants,  such as vitamin C and vitamin E reduce the possibility of oxidation of LDL cholesterol.

Nicotinic acid derivatives. Niacin inhibits VLDL cholesterol synthesis in the liver and affects almost all types of hyperlipidemia.

While using all these drugs, the regular control of liver enzymes is necessary because of the possible liver damage.

 

PROGNOSIS

The prognosis depends on a number of factors. Provided timely diagnosis of disease, even patients with a serious problem by regularly taking medications can live a long time. Serious problem is an individual whose disease is not clinically manifested, with sudden cardiac death or rupture of the aneurysm being the first symptom of already existing atherosclerosis.

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