Bma Illustrated Medical Dictionary

diabetes mellitus. Atherosclerosisof the

coronary arteries is usually a factor.

Symptoms include sudden pain in the

centre of the chest, breathlessness,

feeling restless, clammy skin, nausea

and/or vomiting, or loss of conscious-

ness. Myocardial infarction may cause

immediate heart failureor arrhythmias.

Diagnosis is made from the patient’s

history and tests including ECGand

measurement of enzymesreleased into

the blood from damaged heart muscle.

A myocardial infarction is a medical

emergency. Initial treatment may include

aspirin, thrombolytic drugs, analgesic

drugs, and oxygen therapy. Diuretic

drugs, intravenous infusionof fluids,

antiarrhythmic drugs, and beta-blocker

drugs may also be given. Electrical

defibrillationmay be used to control

severe arrhythmias.

After recovery, preventive measures

such as taking more exercise, losing

weight, stopping smoking, and dietary

changes are recommended. Statindrugs

are usually given to lower blood choles-

terol; aspirin or beta-blocker drugs are

given to reduce the risk of further attacks.

myocarditisInflammation of the heart

muscle, usually due to infection by the

coxsackievirus. Myocarditis is a charac-

teristic feature of rheumatic fever.

There are often no symptoms. Rarely,

there may be a serious disturbance of

the heartbeat, breathlessness, chest

pain, and heart failure. In severe cases,

death may result from cardiac arrest.

Myocarditis may be suspected from

the patient’s history and from a physical

examination. An ECGwill show charac-

teristic abnormalities of the heartbeat.

Diagnosis also involves echocardio-

graphyand blood tests.

There is no specific treatment. Bed rest

is usually recommended andcortico-

steroid drugsmay be prescribed.

myoclonusRapid and uncontrollable

jerking or spasm of one or more mus-

cles either at rest or during movement.

Myoclonus may be associated with a

muscular or nervous disorder. It also

occurs in healthy people, such as when

the limbs twitch before sleep.

myofascial pain syndromeSee tem-

poromandibular joint syndrome.

myoglobinAn oxygen-carrying pigment

that is present in muscles. It consists of

a combination of iron and protein. Myo-

globin stores oxygen, releasing it when

it is needed by the muscles. The pres-

ence of myoglobin in the urine is known

as myoglobinuria. Slight myoglobinuria

may occur during prolonged exercise.

Severe myoglobinuria is usually caused

by the release of myoglobin from a

large area of damaged muscle, and may

cause kidney failure.

myomaA noncancerous muscle tumour.

myomectomySurgical removal of a

myoma. The term is also used to

describe the surgical removal of fibroids

from the uterus.

myopathyA disease of musclethat is

not caused by disease of the nervous

system. A myopathy may be an inherited

disorder, such as muscular dystrophy; it

may also be caused by chemical poison-

ing, a chronic disorder of the immune

system, or a metabolic disorder.

myopiaAn error of refractionin which

objects seen in the distance appear

blurred. Commonly called shortsighted-

ness, myopia is caused by the eye being

too long from front to back. As a result,

images of distant objects are focused in

front of the retina.

MYOCARDITIS MYOPIA

M

MYOPIA

Light rays

from distant

object

Lens

Light

rays

focused

on retina

Lens

Light rays

focused in

front of

retina

Cornea

NORMAL MYOPIA

Light rays

from distant

object

Cornea

Retina Retina