Various chemicals and some drugs, particularly those used in the treatment of cancer, can dam­age the heart muscle. К q: How is myocarditis diagnosed and treated?

A: A physician makes an initial diag­nosis from the symptoms and con­firms it with an electrocardiogram I (EKG) and other heart investiga­tions. Treatment is directed at the cause, once it has been discovered. The patient must have complete rest and may require oxygen. Corti­costeroid drugs might be helpful, but must be used with caution. See also corticosteroid; electrocardi­ogram.

Myoclonus (mi б klo'nas) is a brief spasm of muscular contraction that fe involve a group of muscles, a sin­gle muscle, or only a number of muscle fibers. Often, the contractions occur rhythmically, producing a regular twitching of the affected muscle. If my­oclonus involves several muscles, it may be sufficiently violent to cause the person to fall over. The treatment de­pends on the cause. There is a variety of antispasmodic drugs that may help to reduce the likelihood of my­oclonus.

Myoma (mi б'тэ) is a tumor on the uterine muscle. Most myomas are be­nign (noncancerous), although a few may become malignant (cancerous).

Myopathy (ml ар'э the) is any muscular disorder that results in weakness and degeneration of the muscle tissue that is not caused by a defect in the nervous system. The muscular dystrophies are classified as myopathic disorders.

See also muscular dystrophy.

Myopia (mi б'рё э) is the medical term for nearsightedness, a visual defect in which distant objects can not be seen clearly. It occurs because light entering the eye is focused in front of the retina instead of on it. Distant objects are out of focus because either the lens of the eye is too curved, bending the light rays too much or the eyeball is too long, a condition that seems to be in­herited. Close objects can be seen sharply, and even in old age, near­sighted people may be able to read eas­ily without glasses.

Myopia can be corrected with contact lenses or by wearing eyeglasses with concave (converging) lenses.

. Heart disease, congenital (кэп jen'a tel). Congenital heart disease is any heart disorder that is present at birth, although the condition may not be di­agnosed until later in life. The most common problems are a hole between the two ventricles; a narrowing of the aorta, the main artery from the heart; the wrong positioning of the aorta or the artery that leads to the lungs; and constriction of the valves in the left side of the heart, with weakness of the heart muscle.

Q: What are the symptoms of congen­ital heart disease? A: The symptoms, if present at all, depend on the nature of the disor­der. Many types of defects produce, murmurs. A baby may have diffi­culty in sucking, eating, or breath­ing. There may also be a bluish color to the skin. An infant with congenital heart disease is likely to have frequent respiratory infec­tions. See also blue baby; Fallot's

tetralogy.

Q: What are the causes of congenital heart disease?

A: Often, the cause is unknown, al­though genetic factors are thought to be important. Some forms of congenital heart disease may be caused by a virus infection in the mother during the first three

Disease, coronary

V

months of pregnancy, such as ru­bella. See also rubella. Q: How is congenital heart disease treated?

A: Successful treatment depends on a speedy diagnosis. If possible, the appropriate type of heart surgery is then undertaken. Q: Are some babies more susceptible to congenital heart disease than others?

A: Yes. Although about 1 percent of first-born babies have a congenital heart disease, the likelihood of it occurring in a subsequent baby is increased to 1 in 25. There is also a 1 in 25 chance that a baby born to parents, one of whom has a con­genital heart disorder, will also have a heart problem.

Heart disease, coronary (кбг'э пег ё).

Coronary heart disease is any damage to the heart muscle resulting from re­duced blood supply from the two coro­nary arteries. Normal blood supply is reduced by the narrowing of any sec­tion of an artery. The type of arterio­sclerosis known as atherosclerosis, a build-up of fatty deposits in the arterial walls, is the most common cause. The artery usually affected is the first de­scending branch of the left coronary ar­tery.

Q: What are the symptoms of coro­nary artery disorders? A: Sometimes, a pain in the center of the chest (angina pectoris) occurs during exercise. Such pain usually vanishes when the exercise ceases. Often, there are no symptoms at all until thrombosis (blood clotting) shuts off the blood supply com­pletely. This causes death of part of the heart muscle, a condition known medically as myocardial in­farction. In popular usage it is called a "coronary" or "heart at­tack." See also heart attack;

heart disease. Q: What are the symptoms of a heart attack?

A: The patient usually complains of severe, tight, constricting pain in the chest. This may extend to the shoulders, arms, and hands, into the neck and jaw, and sometimes down into the upper abdomen. The pain may be accompanied by sweating. A patient with the*, symptoms should be hogplJjf as soon as possible. It is also ^ ble to have a "silent" heart at?⁰^' with no symptoms, which m ■ only be discovered much later^- an electrocardiogram (EKG). ту most often occurs in elderlv m tients.

Q: How long does the pain last?

A: The pain may last from a few utes to several hours, after which the patient is exhausted.

Q: Does the heart stop beating?

A: If the condition is severe, it i_s p_0s sible for the heart to stop beatiiJ If the heartbeat is not restored b. mediately, death occurs.

Q: How is a heart attack diagnosed?

A: The diagnosis of a heart attack is made by studying the patient's his- I tory of pain, by observing charac­teristic changes in the electrocardi- ogram, and by detecting the presence of various enzymes in the blood.

Q: What is the treatment for a heart attack?

A: The first hours of treatment are the most critical. The patient may be admitted to a coronary care unit, where electrocardiographic moni­toring is done to detect any irregu­larities in the pulse. Such irregu­larities may indicate that the heart may be about to stop. Pulse irregu­larities can be treated with drugs. Injections of painkilling drugs can be given if needed. If a blood clot was the cause of the heart attack, drugs should be administered to dissolve the thrombosis. Other drugs (for example, heparin or warfarin) can be given to prevent thrombosis. After two to three days, the most dangerous period is over, and the patient is usually permitted to get out of bed. This reduces the chance of deep vein thrombosis in the legs.

Q: For how long may a coronary heart disease patient be hospital­ized?

A: It depends on the severity of the obstruction to the blood supply and on any complications. A pa­tient may be hospitalized for about 10 davs а «Дм