The arteries are the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body. Each artery is a muscular tube lined by smooth tissue and has three layers:
- The intima, the inner layer lined by a smooth tissue called endothelium
- The media, a layer of muscle that lets arteries handle the high pressures from the heart
- The adventitia, connective tissue anchoring arteries to nearby tissues
The largest artery is the aorta, the main high-pressure pipeline connected to the heart's left ventricle. The aorta branches into a network of smaller arteries that extend throughout the body. The arteries' smaller branches are called arterioles and capillaries. The pulmonary arteries carry oxygen-poor blood from the heart to the lungs under low pressure, making these arteries unique.
Conditions of the Arteries
- Atherosclerosis: The buildup of cholesterol (a waxy substance) into what are called plaques in the arteries' walls. Atherosclerosis in the arteries of the heart, brain, or neck can lead to heart attacks and strokes.
- Vasculitis (arteritis): Inflammation of the arteries, which may involve one or more arteries at the same time. Most vasculitis is caused by an overactive immune system.
- Amaurosis fugax: Loss of vision in one eye caused by a temporary loss of blood flow to the retina, the light-sensitive tissue that lines the back of the eye. It usually occurs when a portion of a cholesterol plaque in one of the carotid arteries (the arteries on either side of the neck that supply blood to the brain) breaks off and travels to the retinal artery (the artery that supplies blood and nutrients to the retina.)
- Stenosis of the arteries: Narrowing of the arteries, usually caused by atherosclerosis. When stenosis occurs in arteries in the heart, neck, or legs, the limitations in blood flow can cause serious health problems.
- Peripheral artery disease: Atherosclerosis that causes narrowing of the arteries in the legs or groin. The limitation in blood flow to the legs may cause pain or poor wound healing.
- Arterial thrombosis: A sudden blood clot in one of the arteries, stopping blood flow. Immediate treatment is necessary to restore blood flow in the artery.
- Myocardial infarction (heart attack): A sudden blood clot in one of the arteries supplying blood to the heart.
- Cerebrovascular accident (stroke): A sudden blood clot in one of the arteries supplying blood to the brain. Strokes may also occur when one of the arteries in the brain bursts, causing bleeding.
- Temporal arteritis: Inflammation of the temporal artery in the scalp. Pain in the jaw with chewing and pain over the scalp are common symptoms.
- Coronary artery disease: Atherosclerosis with narrowing of the arteries supplying blood to the heart muscle. Coronary artery disease makes a heart attack more likely.
- Carotid artery disease: Atherosclerosis with narrowing of one or both of the carotid arteries in the neck. Disease of the carotid arteries makes stroke more likely.
Tests of the Arteries
- Angiogram (angiography): A thin, flexible tube is inserted into the arteries, special dye is injected, and an X-ray shows blood flow through the arteries. Areas of narrowing or bleeding in the arteries can often be identified through angiography.
- Computed tomographic angiography (CT-A scan): A CT scanner takes multiple X-rays, and a computer compiles them into detailed images of the arteries. A CT-A scan can often show narrowing or other problems in the arteries with less risk than regular angiography.
- Stress test: Either with exercise or medicines, the heart is stimulated to beat rapidly. As this stress increases blood flow through the heart, narrowings in the coronary arteries may be identified through various testing techniques.
- Magnetic resonance angiography (MRA scan): An MRI scanner uses a high-powered magnet and a computer to create highly detailed images of structures inside the body. MRA is a setting that allows an MRI scanner to best display images of the arteries.
- Cardiac catheterization: A catheter (a thin, flexible tube) is inserted into one of the arteries in the groin, neck or arm and advanced into the heart. A dye that improves image contrast is injected through the catheter so that blood flow through the coronary arteries can be seen on an X-ray screen. Blockages in the arteries may then be found and treated.
- Artery biopsy: A small piece of an artery is removed and examined under a microscope, usually to diagnose vasculitis. The temporal artery in the scalp is most often biopsied.
Treatments for the Arteries
- Statins: Cholesterol-lowering medicines taken by mouth, including atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altoprev, Mevacor), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor). Taken daily, statins can lower the risk of a heart attack or stroke.
- Aspirin: In addition to its pain-reducing and fever-reducing properties, aspirin interferes with blood clotting. Taken daily, aspirin can help prevent heart attacks and strokes.
- Plavix (clopidogrel): A medicine that interferes with blood clotting, similar to aspirin. Plavix is commonly prescribed after heart attacks or strokes to prevent future ones.
- Arterial stenting: A stent -- a small mesh tube -- is placed inside an artery to hold it open. Stenting is most often performed on the coronary arteries.
- Angioplasty: During a catheterization of one of the arteries, a balloon is inflated inside the artery to help open it up.
- Corticosteroids: Anti-inflammatory medicines like prednisone or methylprednisolone (Solu-medrol) are used to treat vasculitis affecting the arteries.
- Biologics: A biologic drug called tocilizumab (Actemra) may be used. Tocilizumab is given as an injection under the skin.This medicine may be used along with steroids.
- Thrombolytics: Powerful "clot-busting" drugs may be injected into the body to dissolve a blood clot causing a heart attack or stroke.
- Cilostazol (Pletal) and pentoxifylline (Trental): Medicines that help increase blood flow through the arteries of the legs. In people with peripheral artery disease, these drugs can reduce the pain of walking.