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 butinterfere with the pumping
action of the heart.
Aneurysms of the aorta may be detec-
ted by ultrasound scanning, and cerebral
aneurysms by CT scanningor MRI. Angi-
ographyprovides information on all
types of aneurysm. Ruptured or enlarged
aneurysms require immediate surgery
(see arterial reconstructive surgery).
anginaA strangling or constrictive pain.
Angina has become synonymous with
the heart disorder angina pectoris. Other
types of angina include abdominalangi-
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 pectorisPain 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
anaemiaand polycythaemia, 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 drugsor calcium channel
blockersmay be used.
Drug treatment can control the symp-
toms for many years. If attacks become
more severe or more frequent, despite
treatment, coronary artery bypasssur-
gery or angioplastymay be necessary.
angioedemaA 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
drugsmay relieve symptoms.
angiogenesisThe 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.
angiographyAn imaging procedure
that enables blood vessels to be seen
clearly on X-ray film following the injec-
tion of a contrast medium(a substanceANGINA ANGIOGRAPHY
A