Atherosclerosis is the build up of plaque on the inside of blood vessels. Atherosclerosis is often called arteriosclerosis, which is a general term for hardening of the arteries.
Atherosclerosis, a progressive condition responsible for most heart disease, is a type of hardening of the arteries. It can be caused by normal aging processes, by high blood pressure, and by some diseases, such as diabetes. Atherosclerosis can begin in the late teens, but it usually takes decades for the signs and symptoms of the disease to be apparent. Some people experience rapidly progressing atherosclerosis in their 30s or later.
An artery is made up of several layers: an inner lining called the endothelium, an elastic membrane that allows the artery to expand and contract, a layer of smooth muscle, and a layer of connective tissue. Atherosclerosis affects the inner lining of an artery. It is characterized by plaque deposits that block the flow of blood. Plaque is made of fatty substances, cholesterol, waste products from the cells, calcium, iron, and fibrin, a material that helps clot blood.
As plaque builds up in and around the cells of the artery walls, they accumulate calcium. The innermost layer thickens, the artery's diameter is reduced, and blood flow and oxygen delivery are decreased. Plaque can rupture or crack open, causing the sudden formation of a blood clot, called a thrombosis. As a result of thrombosis and/or the buildup of plaque, atherosclerosis can cause a heart attack if it completely blocks the blood flow in the coronary arteries. It can cause a stroke if it completely blocks the carotid arteries of the brain. Atherosclerosis can also occur in the arteries of the neck, kidneys, thighs, and arms, and may lead to kidney failure, gangrene, and even death.
Causes & symptoms
It is thought that atherosclerosis is caused by the body's response to damage to the artery wall from cholesterol, high blood pressure, and cigarette smoking. A person who has all three of these risk factors is eight times more likely to develop atherosclerosis than is a person who has none. Physical inactivity, damage by oxidants, diabetes, and obesity are also risk factors for atherosclerosis. High levels of the amino acid homocysteine and abnormal levels of fats called lipoproteins also raise the risk. Other risk factors include:
- High triglycerides. Most fat in food and in the body takes the form of triglycerides. Blood triglyceride levels above 400 mg/dL have been linked to atherosclerosis.
- Physical inactivity. Lack of exercise increases the risk of atherosclerosis.
- Diabetes mellitus. The risk of developing atherosclerosis is seriously increased for diabetics and can be lowered by keeping diabetes under control. Many diabetics die from heart attacks caused by atherosclerosis.
- Obesity. Excess weight increases the strain on the heart and increases the risk of developing atherosclerosis, even if no other risk factors are present.
- Heredity. People whose parents have coronary artery disease, atherosclerosis, or stroke at an early age are at increased risk.
- Sex. Before age 60, men are more likely to have heart attacks than women.
- Age. Risk is higher in men who are 45 years of age and older and women who are 55 years of age and older.
The symptoms of atherosclerosis differ depending upon the location. They may involve:
- In the coronary (heart) arteries: chest pain, heart attack, and sudden death.
- In the carotid arteries of the brain: sudden dizziness, weakness, loss of speech, and blindness.
- In the femoral arteries of the legs: cramping and fatigue in the calves of the legs when walking.
- In the renal arteries of the kidneys: high blood pressure resistant to treatment.
Physicians may be able to make a diagnosis of atherosclerosis during a physical exam by means of a listening to the activity of the arteries and the heart with a stethoscope and probing them with the hands. More definitive tests are usually called for, however. These include an electrocardiogram, which shows the heart's activity; exercise electrocardiography, more familiarly known as a stress test, conducted while the patient exercises on a treadmill or a stationary bike; echocardiography, a type of ultrasound using sound waves to create an image of the heart's chambers and valves; and ultra-sonography to assess arteries of the neck and thighs.
Radionuclide angiography and thallium scanning use radioactive material injected into the bloodstream. These tests enable physicians to see the blood flow through the coronary arteries and the heart chambers and to record pictures of the heart. Coronary angiography is the most accurate diagnostic method for artheroscerosis, and it is also the only invasive procedure. A cardiologist inserts a catheter equipped with a viewing device into a blood vessel in the leg or arm and guides it into the heart. A contrast dye makes the heart visible to x rays. Motion pictures are taken of the dye flowing though the arteries, and plaques and blockages are well defined.
The most common treatments focus on dietary and lifestyle changes to reduce cholesterol and other problems that contribute to atherosclerosis. Dietary modifications usually incorporate eating foods that are low in saturated fats, cholesterol, sugar, and animal proteins. Foods high in fiber, such as fresh fruits and vegetables, and whole grains, are encouraged. By consuming fruits and vegetables, the person also consumes helpful dietary antioxidants, such as carotenoids found in vegetable pigments, and bioflavenoids in fruit pigments. Liberal use of onions and garlic is recommended, as well as eating fish, especially cold-water fish, such as salmon. Smoking, alcohol, and coffee are to be avoided; and exercise is strongly recommended. There are several well-known programs, such as those created by Nathan and Robert Pritikin and Dean Ornish, which are very helpful in setting up and maintaining dietary and lifestyle programs.
Herbal remedies for atherosclerosis include garlic (Allium sativum), ginger (Zingiber officinale), hawthorn (Crataegus oxycantha), (Ginkgo biloba), and Siberian ginseng root (Eleutherococcus senticosus). Gugulipids, or myrrh (Commiphora molmol) is highly regarded for its ability to lower cholesterol and triglyceride levels. Other herbs with this ability include alfalfa (Medicago sativum), turmeric (Curcuma longa), (Panax ginseng), and fenugreek (Trigonella foenum-graecum). Atherosclerosis is a complex condition. Therefore, a knowledgeable practitioner of herbal healing should be consulted for recommendations on the right combination of herbs and dosages.
Chelation therapy involves injecting a drug called EDTA and drug taken orally called DMSA, together with nutrients into the bloodstream. It is thought to work by either binding to the calcium in plaque and transporting it for excretion, or by acting as an antioxidant, or by both methods. It has shown some success, but it remains a controversial method.
Several disciplines can offer helpful long-term treatment strategies for those with atherosclerosis. A knowledgeable practitioner should be consulted. Ayurvedic medicine practitioners combine diet, herbal remedies, relaxation, and exercises. A homeopath will prescribe a treatment regimen based on a complete assessment. A traditional Chinese medicine practitioner may prescribe a combination of herbs such as siler (Ledebouriellla divaricata), Platycodon grandiflorum, Polygonum multiflorum, and Bupleurum chinense. Acupuncture and massage may be recommended, particularly for the accompanying circulatory problems. A homeopath will prescribe remedies based on an in-depth interview and evaluation.
Stress is known to worsen blood pressure and atherosclerosis, and hasten the progression of the disease. Therapeutic relaxation techniques are, therefore, helpful adjuncts to treatment. Recommended approaches include yoga, meditation, guided imagery, biofeedback, and counseling. In fact, a 2002 study showed that transcendental meditation, when combined with diet, exercise and antioxidant food supplements, contributed to nearly a 33% reduced long-term risk for heart attack and stroke in some patients.
Allopathic treatment includes medications, balloon angioplasty, and coronary artery bypass surgery. Most of the drugs prescribed for atherosclerosis seek to improve conditions that contribute to the disease, such as high cholesterol, blood clots, or high blood pressure.
Angioplasty and bypass surgery are invasive procedures that improve blood flow in the coronary arteries. Coronary angioplasty is performed by a cardiologist. It is a nonsurgical procedure in which a catheter tipped with a balloon is threaded from a blood vessel in the thigh into the blocked artery. When the balloon is inflated, it compresses the plaque and enlarges the blood vessel to open the blocked artery. In one–third of patients, the artery narrows again within six months. The procedure may have to be repeated and a wire mesh stent may be placed in the artery to help keep it open. In bypass surgery, a detour is created with grafted or synthetic blood vessels. The blood can then go around the blockage. Other procedures may be used, including catheterization and laser treatments.
Atherosclerosis can be successfully treated, but not cured. Studies have shown that atherosclerosis can be delayed, stopped, and even reversed by aggressively lowering cholesterol and changing the diet.
A healthy lifestyle—eating right, regular exercise, maintaining a healthy weight, not smoking, and controlling hypertension—can reduce the risk of developing atherosclerosis, help keep the disease from progressing, and sometimes cause it to regress. A 2002 study presented promising news about the impact of simple exercise on modifying the elasticity of one's arteries. A small group of healthy but sedentary postmenopausal women began walking at a moderate pace for 40 to 45 minutes a day five times a week. By the end of 12 weeks, 48% of the women had restored elasticity to their carotid arteries.
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