Aetiology of arteriosclerosis

A thin layer of endothelium cells forms a lining that keeps the blood smoothly to flow. When the endothecium cells become damaged arteriosclerosis happened. Many factors such as smoking, high blood pressure, diabetes mellitus, or hypercholesterolaemia can cause the damage.

Arteriosclerosis occurs when the blood vessels that carry oxygen and nutrients from the heart to the rest of the body (arteries) become thick and stiff. Perhaps the most important form of arteriosclerosis is coronary heart disease. This leads to narrowing of the arteries that carry blood to the heart muscle, or to clots within their lumen – both of which block circulation.

Healthy arteries are flexible and elastic, but over time, the walls in arteries can harden, a condition commonly called hardening of the arteries. Hardening of the arteries (arteriosclerosis or atherosclerosis), involving principally the vessels of the brain, heart and kidneys, is a major cause of disability or death.

Atherosclerosis a specific type of arteriosclerosis is a disease of the arterial vasculature that is characterized by the disrupted balance and abnormal accumulation of lipids, inflammatory cells, matrix deposits and smooth muscle cell proliferation in and on the artery walls (plaque), which can restrict blood flow.

Arteriosclerosis in man develops earlier and more frequently in individuals with high blood cholesterol levels than in those with normal blood cholesterol. Arteriosclerosis usually affects older people, but it can start to develop during adolescence.

Aetiology of arteriosclerosis

Cardiomyopathy

Cardiomyopathy refers to any disease that affects the heart muscle, this diminishing cardiac performance. It is a rare form of heart disease that affects only the heart muscle.

The term cardiomyopathy is derived from the word cardio, the heart, and myopathy, which indicates a weakness or disturbance of the muscle.

Cardiomyopathy occurs in three major types: dilated congestive, hypertrophic and restrictive. Dilated congestive, the most common, is the form seen in children and occur in autosomal dominant, X-linked and sporadic forms.

The heart loses its ability to pump blood and in some instances, heart rhythm is disturb, leading to irregular heartbeats or arrhythmias.

 The causes of cardiomyopathy are somewhat reflected in their names. Primary cardiomyopathy refers to cardiomyopathy of unknown etiology. Hypertrophic cardiomyopathy is a specific type of primary cardiomyopathy in which the cause in uncertain. Hypertrophic cardiomyopathy is found throughout the world with a prevalence in North America of 0.2%.

Secondary cardiomyopathy is cardiomyopathy due to a well-defined systemic disease. For instance, alcoholic cardiomyopathy, as to its name implies, is due to long standing alcohol abuse.
Cardiomyopathy

Fibromuscular dysplasia

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory vascular disease that affects any and/or all the three layers in the cephalic, renal and both extracranial and intracranial arteries (particularly the bilateral internal carotid arteries).

On angiography the vessels have a corrugated, complicated or ‘string-of-beads’ appearance. The dilated segments are larger than normal, whereas the lumen of the narrow segments is reduced to 40% of normal.

The exact cause remains unknown although genetic predisposition, trauma, hormonal factors, growth factors, underlying, connective tissue disease, skeletal factors and metabolic and immunological factors have all been proposed as cause of fibromuscular dysplasia.

The increased incidence of fibromuscular dysplasia in women as compared with men suggests a possible hormonal or genetic influence. Some authors have proposed the sex difference to be related to immune system functioning, but overt inflammation, as is observed in most classic autoimmune disease is histological lacking.

Aneurysms and dissection are not uncommon complications of fibromuscular dysplasia. Aneurysms can rupture, causing severe life-threatening bleeding. Such aneurysms are usually treated surgically or can sometimes be embolized using endovascular techniques.
Fibromuscular dysplasia

Carotid artery stenosis

Carotid artery disease or carotid artery stenosis is a disease developed due to cardiovascular incapacity and cerebral infraction. Carotid artery disease is related with deep, subcortical or cortical infarctions.

The most common cause of carotid artery disease is atherosclerosis. Ischemic stroke results form a mural thrombosis at a site of atherosclerotic plaque leading to artery-to-artery atheroembolism or to occlusive thrombus.

Less common cause of carotid artery disease include Takayasu arteritis, giant cell arteritis, fibromuscular dysplasia, dissection, and radiation-induced arteriopathy.

The two external carotid arteries, one on each side of the neck, supply blood to the brain and eyes.

The beginning of the internal carotid artery and the middle or anterior cerebal artery are the most common sides so atherosclerosis. A superimposed clot leads to a ‘transient ischemic attack’ or a stroke.

Primary prevention of carotid artery disease involves the management of modifiable risk factors for atherosclerosis. If one:
*Smokes, stop - avoid secondhand smoke
*Has hypertension - take measures to normalize blood pressure
*Is sedentary - engage in physical activities and exercise
*Manifests abnormal blood lipid levels - modify levels to acceptable limits with diet, exercise and medication
*Is diabetic - establish measures to ensure tight control of blood glucose and lipid levels
*Feels stressed - reduce or minimize stress level and learn to cope effectively
Carotid artery stenosis

Carotid artery disease

The carotid arteries are the large arteries in the neck that supply blood to the brain. If plaque from atherosclerosis clogs these arteries, doctors call it carotid artery disease (which is a type of peripheral vascular disease).

This can potentially cause decreased blood flow to parts of the brain and can be the cause of a stroke (called a cerebrovascular accident, CVA for short).

Carotid artery disease is one of the additional risk factors for development or present of atherosclerotic coronary heart disease in patents of all ages, including the elderly.

Patients with asymptomatic carotid artery disease have a higher risk of cardiac ischemic event than of a stroke.

Factors that lead to evaluation for carotid artery disease include high-risk patients, suspicious neurological symptoms, and carotid bruits. Seizure, migraine and cardiogenic syncope cam mimic the signs and symptoms of cerebrovascular disease.
Carotid artery disease

Pulmonary insufficiency

In pulmonary insufficiency, blood ejected into the pulmonary artery during systole flows back into the right ventricle during diastole, causing a fluid overload in the ventricle and ventricular hypertrophy; it may ultimately result in right-sided heart failure.

Pulmonic insufficiency is frequently very difficult to appreciate on physical exam, particularly if the pulmonary pressures are normal.

In the fetus, severe pulmonary inefficiency causes hydrops and death.

Alternately, pulmonary insufficiency may be well-tolerated functional disturbance until late adulthood or come to medical attention because of a dilated main pulmonary artery detected on a routine chest x-ray.

The causes of pulmonary insufficiency may be the result of a rare congenital lesion or the stretching of the valvular ring by long lasting pulmonary hypertension. Rarely, prolonged use of a pressure-monitor catheter in the pulmonary artery will lead to this disorder.
Pulmonary insufficiency