Atherosclerosis

Click here to overvire heart disease
 
What is atherosclerosis?


Atherosclerosis refers to the build up of fatty deposits called plaques in the walls of the arteries.
Over time these deposits of cholesterol, fat and the smooth muscle cells that line the arteries are transformed into a thickened and sometimes calcified mass (atheroma).
Atheroma causes the arteries to narrow and lose their elasticity, which leads to a reduction in blood flow through the vessels.

Term watch
What is an artery?
An artery is a blood vessel.
The coronary arteries carry blood to the heart.

What are the symptoms of atherosclerosis?The hardening and narrowing process of atherosclerosis takes many years and can cause no symptoms for a long time.
But when fatty deposits build up to an extent that the artery is significantly damaged, it can cause any of the following.

• Blood clots (thrombus): the fatty deposits that line the arteries can rupture. Blood then clots around the rupture, and the clot may be large enough to block the artery and seal off the blood supply. Depending on where the block is, it may cause stroke, angina (chest pains because the heart lacks oxygen) or a heart attack.
• Ischaemic stroke: a blood clot can cut off the supply of oxygen to an area of the brain. Depending on the size of the affected area and amount of damaged brain tissue, this can cause paralysis, typically affecting only one side of the body.
• Haemorrhagic stroke: when a brain artery affected by atherosclerosis ruptures, usually in someone who also has high blood pressure. This can cause considerable brain damage.
• Reduced heart function (heart failure): when the narrowed artery causes damage to the heart muscle.
• Swelling (aneurysms) in parts of the aorta, the main artery that sends blood to other parts of the body. A segment of blood vessel balloons out, making it weak and prone to rupture. Common sites for these swellings are in the chest (thoracic) and abdominal sections of the aorta.
• High blood pressure and renal failure in the kidneys.
• Leg pains from narrowed arteries in the lower limbs. In extreme cases, insufficient blood supply may result in the leg having to be amputated.

Term watch
Aneurysm: when the wall of a blood vessel balloons out, making it weak and prone to rupture.

Risk factors
Atherosclerosis affects a lot of people. It can start in your 20s and increases with age.
The exact cause of atherosclerosis is unknown, but the following increase your risk of narrowed arteries.

• A family history of atherosclerosis.
• High levels of LDL cholesterol in the blood.
• High blood pressure.
• Smoking.
• Being male.
• Diabetes.
• Excess weight.
• A high fat diet.
• Race.
• High alcohol intake.
• A sedentary lifestyle.

How is atherosclerosis treated? 

Medicines can't cure atherosclerosis or make constricted arteries regain their elasticity.
A cholesterol-lowering medicine can reduce the amount of cholesterol deposited in the arteries and slow the progression of the disease.
Medicines such as low-dose aspirin can prevent blood clots.
Atherosclerosis in the coronary arteries that supply blood to the heart can be treated by medication. This reduces the heart's need for oxygen, lowering pressure on the heart and improving pumping ability.
Blockages can also be treated by the following surgical techniques.

• Balloon dilation (percutaneous transluminal coronary angioplasty or PTA): the narrowed coronary artery is dilated (opened up) with a balloon. A good long-term result can be achieved by then inserting a metal stent (tube) to keep the artery open.
• Bypass operation: a section of blood vessel is taken from another part of your body, usually the leg, and joined to the blocked artery to bypass the obstruction to blood flow.
• Cleaning the artery (endarterectomy): surgery is used to scrape the fatty plaques from inside the arteries. This operation is usually only used for repairing the carotid arteries in the neck.

What can be done to prevent atherosclerosis?

• Eat a varied and healthy diet with plenty of leafy vegetables. Avoid sugary foods and saturated fats found in red meat and full-fat dairy products.
• Stop smoking. Your doctor or pharmacist will be able to provide advice about stop-smoking programmes and medicines that can help you quit.
• Lose weight if you are overweight.
• Exercise more: aim for a half-hour walk each day.
• If you have diabetes or high blood pressure, maintain treatment for these conditions.