CARCINOMATOSIS
C
carcinomatosis
The presence of cancerous tissue in dif-
ferent sites of the body due to the
spread of
cancer
cells from a primary
(original) cancerous tumour.
SYMPTOMS
The symptoms of carcinomatosis may
include weight loss, lack of energy, and
various other problems depending on
the sites of the metastases (secondary
tumours). For example, metastases in
the lungs may cause coughing
and
breathlessness; those that develop in
the liver may cause jaundice.
DIAGNOSIS AND TREATMENT
A diagnosis of carcinomatosis may be
confirmed by
X-rays
or by
radionuclide
scanning
of the bones and lungs, by
biochemical tests, or in the course of
an operation.
Anticancer drugs
or
radio-
therapy
may be given to destroy the
metastases. The condition w ill not be
improved by removing
the primary
tumour unless the tumour is producing
a hormone that directly stimulates the
growth of metastases.
cardiac aneurysm
Ballooning of an area of a ventricle
(lower chamber) of the heart, usually
as a result of damage following a
myo-
cardial infarction
(heart attack). (See also
ventricular aneurysm
. )
cardiac arrest
A halt in the pumping action of the
heart. Cardiac arrest occurs when the
heart’s rhythmic muscular contractions
stop, and usually results from abnormal
electrical activity. It causes sudden col-
lapse, loss of consciousness, and the
absence of pulse and breathing.
CAUSES
The most common cause of cardiac
arrest is a
myocardial infarction
(heart
attack). Other possible causes include
respiratory arrest
,
electrical injury
,
loss of
blood,
hypothermia
,
drug overdose, and
anaphylactic shock
(an extremely severe
type of allergic reaction).
DIAGNOSIS AND TREATMENT
The survival of the patient depends on
prompt restoration of the heartbeat
and the oxygen supply to the brain.
Cardiopulmonary resuscitation
may
be
used to
maintain the circulation until
the heartbeat resumes.
A diagnosis of cardiac arrest can only
be confirmed by m onitoring the elec-
trical activity of the heart using
ECG
.
This helps medical personnel distin-
guish between ventricular fibrillation
(the rapid, uncoordinated contraction
of individual heart muscle fibres) and
asystole (the complete absence of heart
muscle activity), w hich are the two
abnormalities of heart rhythm that can
lead to cardiac arrest.
Ventricular fibrillation may be cor-
rected by
defibrillation
(the application
of an electric shock to the heart). Asys-
tole is more difficult to reverse but may
respond to injection of
adrenaline
or to
an electrical
pacemaker
.
OUTLOOK
In general, recovery after ventricular
fibrillation is more likely than after a
cardiac arrest triggered by asystole.
cardiac arrhythmia
See
arrhythmia, cardiac
.
cardiac asthma
Difficulty in breathing that is sim ilar to
asthma but is the result of
pulmonary
oedema
(fluid on the lungs); the oed-
ema, in turn, is due to
heart failure
(the
inability of the heart to cope w ith its
workload). Attacks of cardiac asthma
usually occur at night. The disorder is
not related to bronchial
asthma
and
requires different treatment.
cardiac catheter
See
catheterization, cardiac
.
cardiac cycle
The sequence of events, lasting for less
than a second, that make up each beat
of the
heart
.
A heartbeat has
three
phases: diastole, atrial systole, and ven-
tricular systole. In diastole, the heart
relaxes. During atrial systole, the
atria
(upper chambers of the heart)
con-
tract, and in ventricular systole, the
ventricles
(the heart’s lower chambers)
contract. The
sinoatrial node
(the heart’s
natural pacemaker) regulates the tim -
ing of the phases by sending electrical
impulses to the atria and the ventricles.
cardiac dysrhythmia
See
dysrhythmia, cardiac.
cardiac massage
Rhythmic compression of the heart.
Cardiac massage is performed when the
heart has stopped beating, in order to
maintain blood circulation, especially
to vital organs such as the brain. It
involves repeatedly squeezing the heart
to force blood out of it and into the
circulatory system, then releasing the
pressure on the heart so that it fills
with blood again. Cardiac massage is
continued until the heart resumes beat-
ing or the person is declared dead.
There are two main types:
external
cardiac massage
,
w hich involves press-
ing on the chest to squeeze the heart,
and
internal cardiac massage
,
when the
exposed heart is massaged by hand.
(See also
cardiopulmonary resuscitation
.)
cardiac muscle
See
muscle
.
cardiac neurosis
Excessive anxiety about the condition
of the heart. Cardiac neurosis usually
follows
a
myocardial infarction
(heart
attack) or heart surgery, but sometimes
occurs when the person has had no
previous heart trouble.
A person who has cardiac neurosis
experiences symptoms that are typical
of heart disease, such as breathlessness
and chest pain, and may be reluctant
to exercise or work for fear of having
a heart attack.
Medical investigation
reveals no physical problem, however.
Psychotherapy
may help an affected
person to overcome the anxiety and
resume a normal, active life.
cardiac oedema
An abnormal build-up of fluid in body
tissues that is caused by
heart failure
(inability of the heart to cope with its
workload). (See also
oedema
. )
cardiac output
The volume of blood pumped by the
heart each minute. Cardiac output is a
measure that is used to assess how effi-
ciently the heart is working. At rest, a
healthy adult’s heart pumps between
2.5
and
4.5
litres of blood per minute.
During exercise, however, this figure
may rise to as much as
30
litres per
minute. A low output during exercise
may indicate damage to the heart mus-
cle or major blood loss.
cardiac stress test
One of a group of tests used to assess
the function of the
heart
in people who
experience chest pain, breathlessness,
or palpitations during exercise. A car-
diac stress test establishes whether the
patient has
coronary artery disease
(in
w hich the blood supply to the heart
muscle is impaired).
An
ECG
machine records the patterns
of the heart’s electrical activity while
the heart is stressed. This is usually
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