Bma Illustrated Medical Dictionary

Before dental or other surgery, patients

with mitral incompetence are given

antibiotic drugsto prevent endocarditis.

mitral stenosisNarrowing of the open-

ing of the mitral valvein the heart. The

left atrium (upper chamber) has to work

harder to force blood through the nar-

rowed valve. Mitral stenosis is more

common in women and may be accom-

panied by mitral incompetence. Stenosis

is usually due to damage to the valve

caused by rheumatic fever.

The main symptom is breathlessness

on exertion. As mitral stenosis worsens,

breathing difficulty eventually occurs

when at rest. Other signs include palpi-

tations, atrial fibrillation, and flushed

cheeks. There may also be coughing up

of blood and fatigue. Possible compli-

cations are as for mitral incompetence.

A diagnosis is made from the patient’s

history, listening to heart sounds, and

by investigations such as an ECG, chest

X-rays, echocardiography, and cardiac

catheterization. Drug treatment is broad-

ly the same as for mitral incompetence.

If symptoms persist, balloon valvulo-

plasty may be carried out to stretch the

valve. Alternatively, heart-valve surgery

may be performed to replace the valve.

mitral valveA valve in the left side of

the heart. The mitral valve is made up of

2 flaps, which allows one-way blood

flow from the left

atriuminto the left

ventricle.

mitral valve pro-

lapseA common,

slight deformity of

the mitral valve,

in the left side of

the heart, that can

produce a degree

of mitral incompet-

ence. The prolapse

is most common in

womenand causes

a heart murmur. It

may be inherited,

but the cause is

often unknown.

Usually, there are no symptoms, and

treatment is not needed. Occasionally,

the condition may produce chest pain,

arrhythmia, or, rarely, heart failure. Often,

no treatment is required for mitral valve

prolapse, but some people may be

treated with beta-blocker drugs, diuretic

drugs, antiarrhythmic drugs, or, rarely,

heart-valve surgery.

mittelschmerzLower abdominal pain

that some women have at the time of

ovulation. The pain is usually one-sided

and lasts only a few hours. It may be

accompanied by slight vaginal blood

loss. In cases of severe mittelschmerz,

oral contraceptives may be prescribed to

suppress ovulation.

MMR vaccinationAdministration of a

combined vaccinethat gives protection

against measles, mumps, and rubella.

The vaccination is offered to all children

at 12–15 months of age, with a booster

shot at 3–5 years. Vaccination is post-

poned if a child is feverish, and it is not

given to children with untreated cancer

or allergiesto aminoglycoside antibiotic

drugssuch as neomycin.

Mild fever, rash,and malaise may

occur after vaccination. In 1 per cent

of cases, mild, noninfectious swelling of

the parotid glandsdevelops 3–4 weeks

after vaccination. There is no evidence

for a link between MMR and Crohn's

diseaseor autism.

mobilizationThe process of making a

part of the body capable of movement.

Mobilization refers to treatment that is

designed to increase mobility in a part

of the body recovering from injury or

affected by disease.

Surgeons use the term to refer to the

freeing of an organ or structure from sur-

roundingconnective tissue and fibrous

adhesions (bands of tissue joining nor-

mally unconnected parts of the body).

moclobemideAn antidepressant drug

used to treat severe resistant depres-

sion and social phobia. Moclobemide is

a reversible monoamine oxidase inhibitor

and is less likely than other MAOIs to

cause high blood pressure. But, as with

all MAOIs, dietary restrictions still apply.

molarSeeteeth.

molar pregnancy A pregnancy in

which a tumour develops from the pla-

cental tissue and the embryo does not

develop normally. A molar pregnancy

may be noncancerous (a hydatidiform

mole) or may invade the wall of the

MITRAL STENOSIS MOLAR PREGNANCY

M

Mitral valve

MITRAL VALVE

Left

atrium

STRUCTURE OF HEART

Left
ventricle