HEART DISEASE, ISCHAEMIC
heart disease, ischaemic
common form of heart disease, in which
narrowing or obstruction of the coronary
results in a reduced blood supply (see
coronary artery disease).
heart, disorders of
A wide range of
disorders can disrupt the heart's action.
In general, genetic factors do not play
a large part in causing heart disorders,
however they do contribute to the
that predispose a per-
. Structural abnormalities
in the heart are among the most
common birth defects (see
Infections after birth may result in
arising from the heart tissues are rare.
They include noncancerous
The heart muscle may become thin
and flabby from lack of protein and
ciency, common in alcoholics, causes
Alcohol poisoning over many years may
cause a type of
is an important factor in heart disease,
probably through its effect on other risk
factors, such as
The coronary arteries may become
narrowed due to
ing areas of heart muscle of oxygen. The
result may be
Some drugs, such as the anticancer
, and even drugs used to treat
heart disease, may disturb the heart-
beat or damage the heart muscle.
Many common and serious heart dis-
orders may be a complication of an
underlying condition, such as cardiomy-
opathy or a congenital defect. Such
disorders include cardiac
some cases of
, and heart
is a failure of the
right side of the heart as a consequence
of lung disease.
Inability of the
cope with its workload of pumping
blood to the lungs and to the rest of the
body. Heart failure can primarily affect
the right or the left side of the heart,
although it most commonly affects both
sides, in which case it is known as con-
gestive, or chronic, heart failure.
Left-sided heart failure may be caused
defect (such as
), or a congenital heart
heart disease, congenital
Other causes of left-sided heart failure
coronary artery disease
The left side of the heart fails to empty
completely with each contraction, or
has difficulty in accepting blood that
has been returned from the lungs. The
retained blood creates a back pressure
that causes the lungs to become con-
gested with blood. This condition leads
Right-sided heart failure most often
which is itself caused by left-sided fail-
ure or by lung disease (such as chronic
obstructive pulmonary disease (see
Right-sided failure can also be due to a
valve defect, such as
or a congenital heart defect.
There is back pressure in the circulation
from the heart into the venous system,
causing swollen neck veins, enlargement
of the liver, and
, especially of
the legs and ankles. The intestines may
become congested, causing discomfort.
Immediate treatment consists of bed
rest, with the patient sitting up.
are given, and
may also be administered.
may be given as emergency
treatment in acute left-sided failure.
Techniques that pro-
vide images of heart structure. Imaging
is used to detect disease or abnormalities.
, the simplest and most
widely used method of heart imaging,
shows heart size and shape, and the
presence of abnormal
and engorgement of
the vessels connecting the heart and
lungs are also usually detectable.