Coronary Heart Disease

Coronary heart disease, the most common type of heart disease caused by atherosclerosis, the buildup of fatty material called plaque on the inside of the coronary arteries (see Arteriosclerosis). Over the course of many years, this plaque narrows the arteries so that less blood can flow through them and less oxygen reaches the heart muscle.

The most common symptom of coronary heart disease is angina pectoris, a squeezing chest pain that may radiate to the neck, jaw, back, and left arm. Angina pectoris is a signal that blood flow to the heart muscle falls short when extra work is required from the heart muscle. An attack of angina is typically triggered by exercise or other physical exertion, or by strong emotions. Coronary heart disease can also lead to a heart attack, which usually develops when a blood clot forms at the site of a plaque and severely reduces or completely stops the flow of blood to a part of the heart. In a heart attack, also known as myocardial infarction, part of the heart muscle dies because it is deprived of oxygen. This oxygen deprivation also causes the crushing chest pain characteristic of a heart attack. Other symptoms of a heart attack include nausea, vomiting, and profuse sweating.

One of the primary risk factors for coronary heart disease is the presence of a high level of a fatty substance called cholesterol in the bloodstream. High blood cholesterol is typically the result of a diet that is high in cholesterol and saturated fat, although some genetic disorders also cause the problem. Other risk factors include smoking, high blood pressure, diabetes mellitus, obesity, and a sedentary lifestyle.

Coronary heart disease cannot be cured, but it can often be controlled with a combination of lifestyle changes and medications. Patients with coronary heart disease are encouraged to quit smoking, exercise regularly, and eat a low-fat diet. Doctors may prescribe a drug such as lovastatin, simvastatin, or pravastatin to help lower blood cholesterol. A wide variety of medications can help relieve angina, including nitroglycerin, beta blockers, and calcium channel blockers. Doctors may recommend that some patients take a daily dose of aspirin, which helps prevent heart attacks by interfering with platelets, tiny blood cells that play a critical role in blood clotting.

Gingivitis

Gingivitis, painless inflammation or degeneration of the gum tissue, or gingiva, considered the first stage of gum disease. The gum tissue between the teeth becomes swollen and uneven; the tissue at the gum line becomes darker; and gums bleed easily. In advanced cases, the mouth will develop a noticeably unpleasant odor.

Gingivitis is caused by the buildup of plaque, a film of bacteria that sticks to the teeth at the gum line. Toxins released from the bacteria irritate the gums, causing the gums to swell and bleed. This enables the bacteria to penetrate just below the gum line into an area known as the gingival sulcus. Warm, moist, and protected from the tongue and the chewing movement of the teeth, the gingival sulcus provides the perfect environment for bacteria to breed. Moreover, the delicate tissues of the sulcus are particularly vulnerable to the strong toxins produced by the bacteria. As the bacteria grow and continue to release toxins, they create a solid pocket of plaque beneath the gum line. This bacteria-filled pocket causes the gums to become more inflamed, which weakens the tissue, allowing even more plaque to be trapped in the expanding pocket.

Left untreated, gingivitis progresses to the next stage of gum disease known as periodontitis. In periodontitis, the inflammation from plaque not only damages the gums but also destroys the bones and ligaments that support the teeth. Eventually, the gums detach from the teeth and the teeth may begin to fall out.

The first step in treating gingivitis is scaling—a thorough professional cleaning of the teeth to remove any plaque. This is particularly important because plaque can harden into a mineral form called calculus or tartar, which can be removed only by professional instruments. In addition, dental structures that can interfere with plaque removal, such as broken fillings or bridges, may be fixed during regular dental cleanings. Most important, the patient will be instructed in proper home care, including regular brushing and effective flossing.

Spasm

Spasm, involuntary and abnormal violent contraction of muscles or muscle tissue. Tonic spasm, or cramp, is characterized by an unusually prolonged and strong muscular contraction, with relaxation taking place slowly. The extreme example of tonic spasm is tetanus, in which the spasms are so violent and so enduring that they may paralyze breathing. In the other form of spasm, called clonic spasm, contractions of the affected muscles take place repeatedly, forcibly, and in quick succession, with equally sudden and frequent relaxations. The most typical examples of clonic spasm are epilepsy and convulsive hysteria.

The medicines used to counteract spasmodic muscular activity are termed antispasmodics. These are used in certain surgical procedures because they block transmission of nervous impulses to the muscles. Derivatives of hemlock and some 50 other plants have a relaxing effect on muscles.

Emphysema

Emphysema, progressive respiratory disease characterized by coughing, shortness of breath, and wheezing, developing into extreme difficulty in breathing, and sometimes resulting in disability and death. Although the exact cause is unknown, bronchial spasm, infection, irritation, or a combination of the three seem to be contributory. The highest degree of occurrence is among heavy cigarette smokers, especially those exposed to polluted air. Children who suffer from bronchitis or asthma are also susceptible.

In the course of the disease the passages leading to the air sacs of the lungs become narrowed. Air is trapped in the sacs, and the tissues of the lungs lose their natural elasticity and undergo destructive changes. Symptoms akin to the common cold or asthmatic wheezing may result. As the disease progresses the volume of residual air trapped in the lungs increases, and the volume of each breath decreases. The lungs increase in size, and in severe cases the patient develops a characteristic “barrel chest.” The lungs become unable to supply enough oxygen to the body tissues. This reduction in oxygen intake causes the heart to pump faster; consequently, the heart becomes strained. Excessive carbon dioxide in the blood gives the patient a bluish skin color.

Elephantiasis

Elephantiasis, disease of the lymphatic system, characterized by an enormous enlargement of the infected area. The hardened skin of this area resembles the hide of an elephant. The disease is usually the result of blockage of the lymphatic system by threadlike filarial worms, usually Wuchereria bancrofti. The parts of the body most frequently affected are the limbs and the genitals. The disease is treated with the antifilarial drug diethylcarbamazine (Hetrazan) and with surgery.