AORTIC STENOSIS
A
LOCATION AND STRUCTURE OF THE AORTA
From its origin at the left ventricle, the
aorta passes upwards, curves behind
the heart, and runs downwards, passing
through the thorax (chest) and into the
abdomen, where it terminates by
dividing into two common iliac arteries.
The aorta is thick-walled and large in
diameter (about 2.5 cm at its origin) to
cope with the high pressure and large
volume of blood that passes through it.
The thick walls of the aorta have an
elastic quality that helps to even out
the peaks and troughs of pressure that
occur with each heartbeat.
SYMPTOMS AND SIGNS
Aortic incompetence may not cause
symptoms; it is sometimes found during
a routine medical examination when the
doctor hears a murmur (abnormal heart
sound) over the front of the chest wall
to the left of the sternum (breastbone).
The heart compensates for the back-
flow of blood into the left ventricle by
working harder, until the combination
of hypertrophy (muscle thickening) and
dilatation (ballooning) of the left ven-
tricle wall
eventually leads to
heart
failure
(reduced pumping efficiency of
the heart); this causes breathing diffi-
culty and
oedema
(a buildup of fluid).
DIAGNOSIS AND TREATMENT
A
chest X-ray, ECG
(measurement of the
electrical activity of the heart), and
echocardiography
(imaging of the heart
structures by measuring the pattern of
reflection of sound waves from them)
may be carried out to diagnose aortic
incompetence. A cardiac catheter (flexi-
ble tube inserted into the heart via
blood vessels) is sometimes used to
demonstrate the degree of incompe-
tence (see
catheterization, cardiac).
Heart failure resulting from aortic
incompetence can be treated with
diur-
etic drugs
or other drugs to remove
retained fluid from the lungs.
Heart-
valve surgery
to replace the damaged
valve may eventually be necessary.
aortic stenosis
Narrowing of the opening of the aortic
valve (one of the
heart valves),
causing
obstruction of blood flow into the cir-
culation. Aortic stenosis makes the heart
work harder and causes the muscle in
the wall of the left ventricle (the main
pumping chamber of the heart)
to
thicken. Narrowing of the valve also
reduces the amount of blood flowing
into the
coronary arteries
(the
main
arteries that supply the tissues of the
heart with oxygen-rich blood).
CAUSES
The most
common cause
of aortic
stenosis is deposition of calcium on the
aortic valve. This deposition is usually
associated
with
atherosclerosis
(fatty
deposits). Aortic stenosis may also be
the result of a
congenital
(present from
birth) abnormality.
SYMPTOMS AND SIGNS
Aortic
stenosis
may
not
cause
any
symptoms; it is sometimes found dur-
ing
a
routine
medical
examination
when the doctor hears a murmur (an
abnormal heart sound) over the front
of the chest wall to the right of the
sternum
(breastbone) and sometimes
up into the neck. Symptoms, when
they do occur, include fainting, lack of
energy, chest pain on exertion as a
result of
angina pectoris,
and breathing
difficulties. Other features, which occur
at a late stage, include a weak pulse and
cardiomegaly,
(enlargement of the heart).
DIAGNOSIS AND TREATMENT
A
chest X-ray,
an
ECG
(measurement of
the electrical activity of the heart), and
echocardiography
(imaging of the heart
structures by measuring the pattern of
reflection of sound waves from them)
may be carried out to diagnose aortic
incompetence. A cardiac catheter (flexi-
ble tube that is inserted into the heart
via blood vessels)
can
be
used
to
demonstrate the degree of stenosis (see
catheterization, cardiac).
Heart-valve surgery
may be needed to
widen or replace the damaged valve.
aortitis
Inflammation of the
aorta
(the main
artery of the body). Aortitis is a rare
condition that occurs in people with
arteritis
(inflammation of the arteries) or
untreated
syphilis
and in some people
with
ankylosing spondylitis
(a disorder
affecting the spine).
Aortitis may cause part of the aorta to
widen and its walls to become thinner.
This may lead to an
aneurysm
(balloon-
ing of the artery), which may burst and
cause severe, sometimes fatal, blood
loss. Aortitis may also damage the ring
around the aortic valve in the heart, lead-
ing to
aortic incompetence
(a condition
which allows the backflow of blood
into the heart), which may eventually
result in
heart failure
(reduced pumping
efficiency of the heart).
aortography
An
imaging
technique
that
enables
the
aorta
(the main artery of the body)
and its branches to be seen clearly on
X-ray
film following injection of a
con-
trast medium
(a substance that is opaque
to X-rays) into the aorta.
HOW AND WHY IT IS DONE
The contrast medium is usually injected
into the aorta through a fine catheter (a
flexible plastic tube) that is inserted
either into the femoral artery at the
groin, the brachial artery on the inside
of the elbow, or directly into the aorta
within the lower abdomen.
Aortography is used if surgery is
needed to treat an
aneurysm
(ballooning
of the aorta).
apathy
The absence of feelings that is often
associated with a lack of energy. Healthy
people may be described as apathetic,
but true apathy is a feature of certain
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