ANGINA
ANGIOGRAPHY
Aneurysms sometimes develop in the
heart wall due to weakening of an area
of heart muscle as a result of
myocar-
dial infarction.
Such aneurysms seldom
rupture but interfere with the pumping
action of the heart.
Aneurysms of the aorta may be detec-
ted by
ultrasound scanning
, and cerebral
aneurysms by
CTscanning
or
MRI. Angi-
ography
provides information on all
types of aneurysm. Ruptured or enlarged
aneurysms require immediate surgery
(see
arterial reconstructive surgery).
angina
A strangling or constrictive pain.
Angina has become synonymous with
the heart disorder
angina pectoris
. Other
types of angina include abdominal angi-
na (abdominal pain after eating caused
by poor blood supply to the intestines)
and Vincent's angina, pain caused by
inflammation of the mouth (see
Vin-
cent's disease).
angina pectoris
Pain in the chest due
to insufficient oxygen being carried to the
heart muscle in the blood.
Inadequate blood supply to the heart
is usually due to
coronary artery dis-
ease
. Other causes include coronary
artery spasm, in which the blood ves-
sels narrow suddenly for a short time,
aortic stenosis
, in which the aortic valve
in the heart is narrowed, and
arrhyth-
mias.
If the pain of angina pectoris
continues, it may be due to
myocardial
infarction
. Rare causes include severe
anaemia
and
pofycythaemia,
which thick-
ens the blood, causing its flow through
the heart muscle to slow.
The pain usually starts in the centre of
the chest but can spread to the throat,
upper jaw, back, and arms (usually the
left one) or between the shoulder-
blades. The pain usually comes on
when the heart is working harder and
requires more oxygen, for example dur-
ing exercise. Angina developing during
sleep or without provocation is known
as unstable angina. Other symptoms
may include nausea, sweating, dizzi-
ness, and breathing difficulty.
Diagnostic tests usually include an
ECG
, which may register normal be-
tween attacks, and a
cardiac stress test
.
Blood tests and coronary
angiography
may also be performed.
To help control the symptoms, it is
important to stop smoking and to lose
weight if necessary. Attacks of angina
pectoris may be prevented and treated
by
nitrate drugs.
However, if nitrates are
not effective or are causing side effects,
beta-blocker drugs
or
calcium channel
blockers
may be used.
Drug treatment can control the symp-
toms for many years. If attacks become
more severe or more frequent, despite
treatment,
coronary artery bypass
sur-
gery or
angioplasty
may be necessary.
angioedema
A type of reaction caused
by
allergy
. Angioedema is characterized
by large, well-defined swellings, of sud-
den onset, in the skin, larynx (voice-
box), and other areas.
The most common cause is a sudden
allergic reaction to a food. Less common-
ly, it results from allergy to a drug (such
as
penicillin
), a reaction to an insect bite
or sting, or from infection, emotional
stress, or exposure to animals, moulds,
pollens, or cold conditions. There is
also a hereditary form of the disease.
Angioedema may cause sudden diffi-
culty in
breathing,
swallowing,
and
speaking, accompanied by swelling of
the lips, face, and neck, depending on
the area of the body affected. Angio-
edema that affects the throat and the
larynx is
potentially life-threatening
because the swelling can block the air-
way, causing
asphyxia.
Severe cases are treated with injections
of
adrenaline
(epinephrine) and may re-
quire intubation (passage of a breathing
tube via the mouth into the windpipe)
or
tracheostomy
(surgical creation of a
hole in the windpipe) to prevent suffo-
cation.
Corticosteroid drugs
may also be
given. In less severe cases,
antihistamine
drugs
may relieve symptoms.
angiogenesis
The growth of new blood
vessels. Angiogenesis is the process
that enables tumours to grow; cancer-
ous cells produce chemicals (called
growth factors
)
that
stimulate
new
blood vessels to form near the tumour,
supplying it with nutrients.
angiography
An
imaging
procedure
that enables blood vessels to be seen
clearly on X-ray film following the injec-
tion of a
contrast medium
(a substance
A
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