Hardening of the Arteries (Arteriosclerosis & Atherosclerosis)

Hardening of the arteries is the common term for arteriosclerosis, which refers to any condition in which the walls of arteries thicken and lose their elasticity. To some degree, this disorder is a natural consequence of aging. Often, however, it stems from atherosclerosis, the accumulation of fatty material in the inner surfaces of arteries. These deposits, or plaque, are composed mostly of cholesterol, a waxy substance that circulates in the blood and is an essential component of cell membranes and several hormones.

Although it can occur in an artery anywhere in the body, atherosclerosis is especially common in the coronary arteries and the carotid artery, which supplies blood to the brain. Fatty deposits in these critical blood vessels can result in a heart attack or a stroke.

What triggers atherosclerosis is unknown, but many scientists think it begins when the innermost layer of the artery, the endothelium, is damaged, perhaps by a virus or immune response that causes inflammation. Although the consequences generally manifest themselves later in life, studies show that the process may begin in early adulthood or even childhood. As deposits of cholesterol, calcium, and other substances accumulate along the walls of a artery, the vessel becomes progressively narrowed, reducing blood flow. Depending upon what vessels are affected, symptoms may include angina, high blood pressure, reduced mental function, leg pains, and kidney failure.

Diagnostic Studies and Procedures

Nearly everyone who is middle-aged or older has some degree of hardening and narrowing of the arteries. In many cases, obvious symptoms don't occur until the condition is well advanced. During a routine physical examination, the doctor may detect signs of arteriosclerosis by listening to the carotid pulse in the neck for whooshing sounds (bruits), or by feeling for a weakened pulse and noting coldness in the feet.

Blood studies to measure cholesterol levels also yield important diagnostic information. In addition to measuring the total amount of cholesterol, these tests should determine the ratio of the protective HDL cholesterol to the detrimental LDL component. HDLs (high-density lipoproteins) carry cholesterol away from the artery walls, whereas LDLs low-density lipoproteins) deposit cholesterol in the artery walls.

The patient's medical history also provides important diagnostic clues. For example, diabetes increases the risk of premature hardening of the arteries. The doctor will ask whether muscle cramps have been felt in the legs, a sign that the femoral arteries may be affected. Of course, the presence of angina suggests involvement of the coronary arteries. The doctor will also ask about lifestyle, as smoking, excessive use of alcohol, and lack of regular exercise contribute to arteriosclerosis. The medical history of close relatives is important as well, because the more severe forms of this condition, which are associated with early death from heart attacks, tend to run in families.

If serious arteriosclerosis involving atherosclerosis is suspected, a doctor may order various X-ray studies to identify the sites of dangerous narrowing. These might include:

Angiography, in which a contrast dye is injected into the bloodstream to make the arteries visible on film.

Positron emission tomography, or PET scanning, which produces three-dimensional pictures of the blood flow to and from the heart.

Cardiac catheterization, in which a narrow tube is inserted into the heart and coronary arteries and a dye or radioactive material is injected.

Doppler ultrasonography, in which echoes from high-frequency sound waves allow a study of the blood flow through specific arteries.

Medical Treatments

If drugs do not work, surgery is often the next recourse. Procedures include:

Balloon angioplasty, in which a catheter, with a deflated balloon at its tip, is inserted into a narrowed artery and then inflated. This widens the artery by flattening plaque against its walls. The progress of the catheter through the artery is monitored by fluoroscopy, a moving X-ray technique, and the balloon is inflated at the site of narrowing.

Angioplasty is most commonly performed on narrowed coronary arteries, the renal artery in the kidney, and vessels in the lower leg. In some cases, it is combined with laser surgery to destroy the plaque. Alternatively, a special device with tiny rotating blades may be inserted through the catheter to shave away the plaque, in a manner similar to the corkscrew action of implements used to unclog plumbing drains.

Bypass surgery, in which a graft, made from a section of a vein or artery removed from somewhere else in the patient, is used to carry blood around portions of narrowed vessels. Coronary bypass surgery is the most common procedure of this type, but bypass operations may also be done on the carotid artery and vessels in the legs.

Endartercctomy, in which the clogged vessel is opened up and fatty deposits are surgically removed. This operation is common on the carotid artery in the neck and arteries in the legs. A patch of Dacron or other synthetic material may be inserted to strengthen the vessel.

Gene therapy, in which genes that direct the growth of new blood vessels are surgically inserted into the blocked artery to encourage formation of a natural bypass around the blockage. This technique is highly experimental, but might someday replace bypass surgery.

Alternative Therapies

Most alternative therapies are directed to modifying the risk factors that underlie atherosclerosis.

Acupuncture. This may be employed to help smokers who cannot break their habit by more conventional means.

Exercise Conditioning. Physicians and alternative therapists alike recommend a program of aerobic exercise to improve circulation, reduce cholesterol, and control obesity, diabetes, and other factors that contribute to atherosclerosis. Walking, cycling, stair climbing, and other activities that use the leg muscles are especially beneficial in alleviating leg pain from reduced circulation. A word of caution, however: Before embarking on any exercise program, have a doctor determine your safe level of physical activity.

Herbal Medicine. Herbalists advocate a number of herbs to reduce cholesterol and improve blood flow. These include American ginseng, taken as capsules, powder, or tea; garlic, in either natural or capsule form; and oil of evening primrose in capsules. Ginger, boiled or consumed as an extract, may be helpful in alleviating leg pain from reduced circulation, and ginkgo tincture or tablets are said to improve general circulation.

Chinese herbalists also recommend the bupleurum and dragon bone combination (bupleurum, pinellia rhizome, skullcap root, ginger, jujube, ginseng, cinnamon, oyster shell, China root, rhubarb, rhizome, and dragon bone, which is pulverized fossil bones) or the major bupleurum combination (bupleurum, skullcap root, pinellia rhizome, peony root, citrus peel, rhubarb rhizome, jujube, and ginger).

Naturopathy and Nutrition Therapy. Practitioners espouse many of the dietary and exercise recommendations made by the medical establishment, but some naturopaths may take diet a step further. They advocate eliminating virtually all dietary fats and oils, meat, and all dairy products other than nonfat milk and yogurt, and at the same time increasing consumption of grains, fruits, vegetables, legumes, and fiber.

A few practitioners recommend daily helpings of alfalfa sprouts, wheat germ, and various supplements, especially vitamins E and C, beta carotene, lecithin, niacin, calcium, and magnesium. Some also advocate fish oil, or omega-3 fatty acid capsules; however, scientific studies of these substances have produced mixed results, with some showing a lowering of cholesterol levels and others finding no benefit or an increased risk of bleeding problems.

Some naturopaths also recommend chelation to remove minerals from the blood, but there is no evidence that this procedure improves atherosclerosis.

Yoga and Meditation. These and other relaxation therapies can reduce stress, which may raise blood pressure and cholesterol and have other detrimental effects on circulation.

Self-Treatment

Lifestyle plays a major role in preventing the premature development of arteriosclerosis and atherosclerosis. Losing excess weight, quitting smoking, exercising regularly, and following a prudent diet, such as that recommended by the American Heart Association (AHA), are the essence of prevention and self-care for hardening of the arteries. The AHA diet is similar to the governments Dietary Guidelines for Healthy Americans, as well as diets advocated by the American Cancer Society.

As far as exercise is concerned, walking or engaging in another aerobic activity for 15 to 30 minutes three or four times a week is needed to maintain fitness and promote good circulation.

Other Causes of Arteriosclerosis

Familial hypercholesterolemia is a genetic disease characterized by extremely high cholesterol levels. People with this condition often have heart attacks early in life, sometimes even during childhood.