ANGINA, PRINZMETAL’S
A
narrowed by
atherosclerosis
(fat deposits
on the artery walls). Other causes inc-
lude coronary artery spasm, in which
the blood vessels narrow suddenly for a
short time,
aortic stenosis,
in which the
heart’s aortic valve is narrowed, and
arrhythmias
(abnormal heart rhythms).
The pain of angina pectoris is brought
on by exertion and is relieved by rest.
If the pain continues, it may be due to a
heart attack (see
myocardial infarction).
Rarer causes of the pain include severe
anaemia,
which reduces the
blood’s
oxygen-carrying
efficiency,
and
poly-
cythaemia,
which thickens the blood and
causes its flow through the heart muscle
to slow down.
SYMPTOMS
The chest pain of angina varies from
mild to severe and is often described as
a sensation of pressure on the chest. The
pain usually starts in the centre of the
chest but can spread to the throat,
upper jaw, back, and arms (usually the
left), or between the shoulderblades. If
it develops during sleep or without
provocation, it is called unstable angina.
Other possible symptoms of angina
pectoris include nausea, sweating, dizzi-
ness, and breathing difficulty.
DIAGNOSIS AND TREATMENT
Diagnostic tests usually include an
ECG
(measurement of the electrical activity
of the heart), which may register nor-
mal between attacks, and a
cardiac stress
test
(an ECG undertaken while the
patient is exercising enough to cause
chest pain). Blood tests and coronary
angiography
(
X-ray
examination of the
blood vessels) may also be performed to
look for an underlying cause.
To help to control the symptoms of
angina pectoris, it is important for the
person to stop smoking and to lose
weight if necessary. Attacks may be
prevented and treated by
nitrate drugs
,
which increase blood flow through the
heart muscle.
Beta-blocker drugs
,
calcium
channel blockers, lipid-lowering drugs,
and
antiplatelet drugs
may also be prescribed.
Drug treatment can control the symp-
toms for many years but cannot cure
the disorder. If attacks become more
severe or more frequent, despite treat-
ment,
coronary artery bypass
surgery or
angioplasty
may be necessary.
angina, Prinzmetal’s
A type of unstable angina pectoris (see
angina, unstable
) in which the attacks of
chest pain occur while the body is at
rest and are not brought on by exertion.
angina, unstable
A type of
angina pectoris
(chest pain due
to impaired blood supply to the heart
muscle) that occurs during sleep or
without provocation (such as exertion).
angioedema
A type of reaction caused by
allergy
.
Angioedema
is
similar
to
urticaria
(hives) and is characterized by large,
well-defined swellings, of sudden on-
set, in the skin, larynx (voice-box), and
other areas. If they are left untreated,
the swellings may last a number of days.
CAUSES
The most common cause of angio-
edema is a sudden allergic reaction to
a food. Less commonly, the condition
may be due to a drug allergy (such as
to
penicillin
), a reaction to an insect bite
or sting, or it may occur as a result of
infection, emotional stress, or exposure
to animals, moulds, pollens, or cold
conditions. There is also a hereditary
form of angioedema.
SYMPTOMS
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.
Angioedema that affects the throat
and the larynx is potentially life-threat-
ening because the swelling can block the
airway, causing asphyxia (suffocation).
TREATMENT
Severe cases are treated with injections
of
adrenaline
(epinephrine)
and may
require intubation (a breathing tube
inserted via the mouth into the wind-
pipe) or
tracheostomy
(surgical creation
Angiogram of brain
Contrast medium is passed through a catheter into
the arteries at the back of the brain, and a series of
X-rays is taken.
of a hole in the windpipe) to prevent
suffocation.
Corticosteroid drugs
may also
be given. In less severe cases,
antihista-
mine drugs
may relieve symptoms.
angiogenesis
The
growth
of new
blood
vessels.
Angiogenesis is the process that enables
tumours to grow: cancerous cells pro-
duce chemicals (called
growth factors)
that stimulate new blood vessels to
form near the tumour, supplying it with
nutrients and oxygen.
angiography
An
imaging
procedure
that
enables
blood vessels to be seen clearly on
X-ray film following the injection of a
contrast medium
(a substance that is
opaque to
X-rays).
Digital subtraction
angiography uses computer techniques
to process images and remove unwanted
background information. Magnetic res-
onance angiography (MRA) can produce
images of blood vessels without the use
of a contrast medium.
WHY IT IS DONE
Angiography is used to detect condi-
tions that alter the appearance of blood
vessels, such as an
aneurysm
(ballooning
of an artery) and narrowing or blockage
of blood vessels by
atherosclerosis
(fatty
deposits lining artery walls), a
thrombus
(abnormal clot), or an
embolus
(frag-
ment of a clot that is carried in the
blood). Angiography is also used to
detect changes in the pattern of blood
vessels that supply organs injured or
affected by a tumour.
Carotid angiography (angiography of
the arteries in the neck) may be used to
Magnetic resonance angiogram of groin
This MRA provides a clear image of the arteries
of the groin area without the need for X-rays or
the injection of radio-opaque dye.
Internal
Cerebral blood
carotid artery
vessels
Aorta
Iliac arteries
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