Artery

Arteries are muscular blood vessels that carry blood away from the heart. All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life. Its proper functioning is responsible for the delivery of oxygen and nutrients to all cells,

as well as the removal of carbon dioxide and waste products, maintenance of optimum pH, and the mobility of the elements, proteins and cells of the immune system. In developed countries, the two leading causes of death, myocardial infarction and stroke each may directly result from an arterial system that has been slowly and progressively compromised by years of deterioration.

The heart pumps blood out through one main artery called the dorsal aorta. The main artery then divides and branches out into many smaller arteries so that each region of your body has its own system of arteries supplying it with fresh, oxygen-rich blood.

Arteries are tough on the outside and smooth on the inside. An artery actually has three layers: an outer layer of tissue, a muscular middle, and an inner layer of epithelial cells. The muscle in the middle is elastic and very strong. The inner layer is very smooth so that the blood can flow easily with no obstacles in its path.

The muscular wall of the artery helps the heart pump the blood. When the heart beats, the artery expands as it fills with blood. When the heart relaxes, the artery contracts, exerting a force that is strong enough to push the blood along. This rhythm between the heart and the artery results in an efficient circulation system.

You can actually feel your artery expand and contract. Since the artery keeps pace with the heart, we can measure heart rate by counting the contractions of the artery. That's how we take our pulse.

The arteries deliver the oxygen-rich blood to the capillaries where the actual exchange of oxygen and carbon dioxide occurs. The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart.

High blood pressure or hypertension means high pressure (tension) in the arteries. Arteries are vessels that carry blood from the pumping heart to all the tissues and organs of the body. High blood pressure does not mean excessive emotional tension, although emotional tension and stress can temporarily increase blood pressure. Normal blood pressure is below 120/80; blood pressure between 120/80 and 139/89 is called "pre–hypertension", and a blood pressure of 140/90 or above is considered high.

The top number, the systolic blood pressure, corresponds to the pressure in the arteries as the heart contracts and pumps blood forward into the arteries. The bottom number, the diastolic pressure, represents the pressure in the arteries as the heart relaxes after the contraction. The diastolic pressure reflects the lowest pressure to which the arteries are exposed.

An elevation of the systolic and/or diastolic blood pressure increases the risk of developing heart (cardiac) disease, kidney (renal) disease, hardening of the arteries (atherosclerosis or arteriosclerosis), eye damage, and stroke (brain damage).

These complications of hypertension are often referred to as end–organ damage because damage to these organs is the end result of chronic (long duration) high blood pressure. For that reason, the diagnosis of high blood pressure is important so efforts can be made to normalize blood pressure and prevent complications.

It was previously thought that rises in diastolic blood pressure were a more important risk factor than systolic elevations, but it is now known that in people 50 years or older systolic hypertension represents a greater risk.

Uncomplicated high blood pressure usually occurs without any symptoms (silently) and so hypertension has been labeled "the silent killer." It is called this because the disease can progress to finally develop any one or more of the several potentially fatal complications of hypertension such as heart attacks or strokes. Uncomplicated hypertension may be present and remain unnoticed for many years, or even decades. This happens when there are no symptoms, and those affected fail to undergo periodic blood pressure screening.

Some people with uncomplicated hypertension, however, may experience symptoms such as headache, dizziness, shortness of breath, and blurred vision. The presence of symptoms can be a good thing in that they can prompt people to consult a doctor for treatment and make them more compliant in taking their medications. Often, however, a person's first contact with a physician may be after significant damage to the end–organs has occurred. In many cases, a person visits or is brought to the doctor or an emergency room with a heart attack, stroke, kidney failure, or impaired vision (due to damage to the back part of the retina). Greater public awareness and frequent blood pressure screening may help to identify patients with undiagnosed high blood pressure before significant complications have developed.

About one out of every 100 (1%) people with hypertension is diagnosed with severe high blood pressure (accelerated or malignant hypertension) at their first visit to the doctor. In these patients, the diastolic blood pressure (the minimum pressure) exceeds 140 mm Hg! Affected persons often experience severe headache, nausea, visual symptoms, dizziness, and sometimes kidney failure. Malignant hypertension is a medical emergency and requires urgent treatment to prevent a stroke (brain damage).

Lifestyle modification

Doctors recommend weight loss and regular exercise as the first steps in treating mild to moderate hypertension. These steps are highly effective in reducing blood pressure, although most patients with moderate or severe hypertension end up requiring indefinite drug therapy to bring their blood pressure down to a safe level. Discontinuing smoking does not directly reduce blood pressure, but is very important for people with hypertension because it reduces the risk of many dangerous outcomes of hypertension, such as stroke and heart attack. An increase in daily calcium intake has also been shown to be highly effective in reducing blood pressure.

Mild hypertension is usually treated by diet, exercise and improved physical fitness. A diet rich in fruits and vegetables and low fat or fat-free dairy foods and moderate or low in sodium lowers blood pressure in people with hypertension. This diet is known as the DASH diet (Dietary Approaches to Stop Hypertension), and is based on National Institutes of Health sponsored research. Dietary sodium (salt) may worsen hypertension in some people and reducing salt intake decreases blood pressure in a third of people. Many people choose to use a salt substitute to reduce their salt intake. Regular mild exercise improves blood flow, and helps to lower blood pressure. In addition, fruits, vegetables, and nuts have the added benefit of increasing dietary potassium, which offsets the effect of sodium and acts on the kidney to decrease blood pressure.

Reduction of environmental stressors such as high sound levels and over-illumination can be an additional method of ameliorating hypertension. Biofeedback is also used particularly device guided paced breathing

There are many classes of medications for treating hypertension, together called antihypertensives, which — by varying means — act by lowering blood pressure. Evidence suggests that reduction of the blood pressure by 5-6 mmHg can decrease the risk of stroke by 40%, of coronary heart disease by 15-20%, and reduces the likelihood of dementia, heart failure, and mortality from vascular disease.

The aim of treatment should be blood pressure control to <140/90 mmHg for most patients, and lower in certain contexts such as diabetes or kidney disease (some medical professionals recommend keeping levels below 120/80 mmHg). Each added drug may reduce the systolic blood pressure by 5-10 mmHg, so often multiple drugs are necessary to achieve blood pressure control.

Commonly used drugs include:

· ACE inhibitors such as captopril, enalapril, fosinopril (Monopril), lisinopril (Zestril), quinapril, ramipril (Altace)

· Angiotensin II receptor antagonists: eg, telmisartan (Micardis, Pritor), irbesartan (Avapro), losartan (Cozaar), valsartan (Diovan), candesartan (Atacand)

· Alpha blockers such as doxazosin, prazosin, or terazosin

· Beta blockers such as atenolol, labetalol, metoprolol (Lopressor, Toprol-XL), propranolol.

· Calcium channel blockers such as amlodipine (Norvasc), diltiazem, verapamil

· Direct renin inhibitors such as aliskiren (Tekturna)

· Diuretics: eg, bendroflumethiazide, chlortalidone, hydrochlorothiazide (also called HCTZ)

· Combination products (which usually contain HCTZ and one other drug)

White coat hypertension is a phenomenon in which patients exhibit elevated blood pressure in a clinical setting but not when recorded by themselves at home. It is believed that this is due to the anxiety some people experience during a clinic visit.

Coronary artery disease (CAD) occurs when the arteries that supply blood to the heart muscle (the coronary arteries) become hardened and narrowed. The arteries harden and narrow due to buildup of a material called plaque (plak) on their inner walls. The buildup of plaque is known as atherosclerosis (ATH-er-o-skler-O-sis). As the plaque increases in size, the insides of the coronary arteries get narrower and less blood can flow through them. Eventually, blood flow to the heart muscle is reduced, and, because blood carries much-needed oxygen, the heart muscle is not able to receive the amount of oxygen it needs. Reduced or cutoff blood flow and oxygen supply to the heart muscle can result in:

• Angina (AN-ji-na or an-JI-na). Angina is chest pain or discomfort that occurs when the heart does not get enough blood.
• Heart attack. A heart attack happens when a blood clot develops at the site of plaque in a coronary artery and suddenly cuts off most or all blood supply to that part of the heart muscle. Cells in the heart muscle begin to die if they do not receive enough oxygen-rich blood. This can cause permanent damage to the heart muscle.

Over time, CAD can weaken the heart muscle and contribute to:

• Heart failure. In heart failure, the heart can’t pump blood effectively to the rest of the body. Heart failure does not mean that the heart has stopped or is about to stop. Instead, it means that the heart is failing to pump blood the way that it should.
• Arrhythmias (a-RITH-me-as). Arrhythmias are changes in the normal beating rhythm of the heart. Some can be quite serious.

CAD is the most common type of heart disease. It is the leading cause of death in the United States in both men and women.

Arm Artery Disease

What is arm artery disease?

Your arteries carry blood rich in oxygen and nutrients from your heart to the rest of your body. When an artery between your chest and your hand becomes blocked, your arm or hand does not receive enough blood or oxygen. You may have a condition called arm artery disease.

Arm artery disease is an uncommon form of peripheral arterial disease (PAD). Most people with PAD have blocked leg arteries, called leg artery disease. Although arm artery disease can come on quickly, it usually starts slowly and gets worse over a long period of time. If you have mild arm artery disease, you may not notice any symptoms. As the disease advances, you may experience pain in the arm with activity and, if it becomes more severe, you eventually may develop sores or gangrene in your arm. Gangrene is tissue death and occurs when tissues in your body do not receive enough oxygen and blood.

Like other types of PAD, arm artery disease can be caused by atherosclerosis, which means hardening of the arteries. Your arteries are normally smooth and unobstructed on the inside, but as you age, a sticky substance called plaque can build up in the walls of your arteries. Plaque is made up of cholesterol, calcium, and fibrous tissue. In atherosclerosis, your arteries narrow or become blocked as plaque builds up on your artery walls.

What are the symptoms?

You may not feel any symptoms from mild arm artery disease. The most common initial symptom is intermittent claudication (IC). IC is discomfort or pain in your arms that happens when you are using your arm and goes away when you rest your arm muscles. Activities that can trigger IC include combing or your washing hair or lifting your arms above your head. You may not always feel pain; instead you may feel tightness, heaviness, cramping, or weakness in your arm.

Other symptoms of arm artery disease include finger pain, sensitivity to cold in your hands, fingers that turn blue or pale, and lack of a pulse in your wrist or your hand.

As the disease gets worse, you may experience pale, cool skin on your arm or hand, blue, slow-growing fingernails, slow-growing arm hair, sores on your fingers, and, eventually, gangrene in your arm or hand.

What causes arm artery disease?

Atherosclerosis is the main cause of arm artery disease. However, several uncommon conditions that can also cause arm artery disease include:

· Buerger’s disease, an inflammation of the small blood vessels and nerves in your hands and feet that usually affects male smokers

· Takayasu’s disease, an autoimmune disease that mostly affects young Asian women. An autoimmune disease means that your immune system attacks your body's organs or tissues

· Raynaud’s disease, in which your hands are extremely sensitive to cold and your fingers turn blue, white, and red in a cool environment

· Diseases such as lupus, scleroderma, and rheumatoid arthritis

· Thoracic outlet syndrome, which is sometimes associated with repetitive motions like pitching in major league baseball

· Embolism, which is a blood clot that travels from one area of your body and blocks a blood vessel in your arm

Rarely, frostbite, radiation therapy for breast cancer, and repeated injury, for example, to the pad of your hand, or other forms of injury, can cause arm artery disease.

Arm artery disease is more likely to affect you if you smoke and are older than age 60. Other risk factors include having high cholesterol or high blood pressure.

What tests will I need?

First your physician asks you questions about your general health, medical history, and symptoms. In addition, your physician conducts a physical exam. Together these are known as a patient history and exam. As part of your history, your physician will ask you if you smoke or have high blood pressure. Your physician will also want to know when and how often your symptoms occur as well as their location.

As part of your exam, your physician will take your blood pressure in both arms. If your blood pressure is significantly lower in one arm, that arm most likely has a blockage. Your physician will feel for a pulse below the suspected blockage. If you have arm artery disease, this pulse will be weak or even missing. Your physician will also listen to your arm arteries with a stethoscope. Abnormal whooshing sounds, called bruits, may suggest blood is flowing through a narrowed artery.

After your exam, if your physician suspects arm artery disease, he or she may perform tests, such as:

· Segmental blood pressures, or taking many blood pressure readings along your arms, hands, and fingers

· Duplex ultrasound

· Chest or neck x-rays

· Computerized axial tomography (CT or CAT scan)

· Magnetic resonance angiography (MRA)

· Angiography (takes x-rays of your arteries)

How is arm artery disease treated?

Your treatment for arm artery disease will depend on the underlying cause, as well as the location and severity of any blockages. If you have high blood pressure, your physician may prescribe medications that treat those conditions. Some prescription medications may help Raynaud's disease. If you have Buerger’s disease, quitting smoking is the most important treatment.

Some physicians use an anesthetic injection, called a sympathetic block, to block certain nerves in the hands. If this procedure relieves your symptoms, your physician may recommend cervical sympathectomy. Cervical sympathectomy can be done surgically or sometimes by chemical injection. This procedure interrupts the nerves that cause your arteries to spasm.

If a large blood vessel in your arm is blocked, your physician may be able to treat it with an angioplasty procedure, depending upon the location and how much of the blood vessel is blocked. During an angioplasty procedure, which is sometimes performed at the same time as an angiogram, a long, thin, flexible tube, called a catheter, is inserted into a small puncture and is guided through your arteries to the blocked area. Once there, a special balloon attached to the catheter is inflated and deflated, several times if needed. The balloon pushes the plaque in your artery against your artery walls, widening the vessel. In some circumstances, a tiny mesh-metal tube called a stent may then be placed into the narrowed area of your artery to keep it open. The stent remains permanently in your artery. After successful angioplasty, blood flows more freely through your artery.

For more extensive blockages, you may need a surgical repair such as endarterectomy or bypass. An endarterectomy is a way for your surgeon to remove the plaque from your artery. To perform an endarterectomy, your vascular surgeon makes an incision and removes the plaque contained in the inner lining of the diseased artery. This leaves a wide-open artery and restores blood flow through it. To perform a bypass, your vascular surgeon creates a detour around your blocked artery with a synthetic tube or a vein from your body.

If the arm blood vessel blockage is associated with Thoracic Outlet Syndrome (see the associated article on Thoracic Outlet Syndrome), a surgical procedure to remove an extra rib or to relieve pressure on the vessel may also be required.

The best choice of the treatment depends upon several considerations including your general health, the pattern and particular cause of the obstruction, and how much blockage that you have. Your vascular surgeon will help you determine which method of treatment is best for your particular situation.

What can I do to stay healthy?

Although many treatments are available for arm artery disease, there is no cure. Lifestyle changes that help you manage risk factors for arm artery disease include:

· Quitting smoking

· Maintain your ideal body weight

· Eating foods low in saturated fat and calories

· Controlling blood cholesterol and lipid (fat) levels

· Exercising and walking regularly, for instance walking at least 30 minutes 3 times each week