|
What is cardiac catheterization? Cardiac catheterization is a diagnostic procedure
in which a long thin tube called a catheter is placed in a blood
vessel and then guided to the heart. The catheter may be inserted into either
arteries or veins, depending on the information needed, in either
an
arm or leg. A contrast medium (commonly called "dye") is
injected through the catheter to determine whether narrowing or blockages
are present in the coronary (heart) arteries, and to measure precisely
how well the heart valves and heart muscle function. Several specialized
procedures may be performed, each tailored to the patient’s special
needs.
Why is this procedure necessary? While stress tests, electrocardiograms (EKG),
echocardiograms, and physical examinations provide considerable
information on heart muscle function and the status of the valves
and surrounding tissue, these procedures do not yield all the
answers. Cardiac catheterization allows the specialist to see an
outline
of the coronary arteries and more precisely determine the extent
of blockages in these vessels.
All of the above procedures are used together
to obtain as much information as possible so that an accurate diagnosis
can be made and proper treatment provided.
What to do before your examBe prepared to answer certain questions your
doctor will ask you about your health.
Your doctor must know if you:
- have a documented
or suspected allergy to any medications, x-ray contrast
media, or foods
- are pregnant
- cannot be flat or on your back for extended
periods of time
- have difficulty urinating, or have been told
of prostate disease
- have glaucoma
- have dentures or a hearing aid (most hospitals
will allow you to take these with you)
- have been taking aspirin,
aspirin-containing products, or "blood thinners," such
as Coumadin or warfarin, or if you have a history of excessive
bleeding
- are diabetic, and if so, are on insulin
- recently have had
or are presently being treated for an infection in any
part of your body
As with other important diagnostic procedures,
you may be asked to sign a consent form before undergoing cardiac
catheterization. Ask questions and make sure you understand the
procedure before you sign the consent form.
You will be admitted either the evening before
or the day of the procedure. A chest x-ray, EKG, and several routine
blood tests will probably be administered. You will be examined,
and different locations of your pulse may be marked.
You may be asked not to eat anything prior to
the procedure. When your scheduled time arrives, your premedications
will be administered, you will change into a hospital gown, and
you will be asked to empty your bladder.
Who performs the procedure? The cardiac catheterization team generally consists
of:
- an x-ray technologist skilled in cardiac studies
- a specially trained nurse
- one or two cardiologists with specialized
training in catheterization
- an anesthetist or anesthesiologist,
if necessary
Each person in the room will be dressed in a
sterile surgical gown and mask.
How is this procedure performed? After being premedicated, you will be brought
to the cardiac catheterization laboratory by stretcher. When you
arrive, the nurses will review your chart and check your vital signs.
A needle attached to an intravenous bottle (or
bag) will be placed in a vein near your wrist. You will then be
moved onto the catheterization table, assisted by the nurses and
technologists.
The groin or arm will be gently shaved and painted
with antiseptic solution. You will then be draped in sterile towels
and sheets. While the equipment is being prepared, the cardiologist
will inject a local anesthetic into the place where the catheter
will be inserted.
If the groin is the site of the insertion, a
small incision in the skin less than 1/4" across will be made
with a sharp scalpel blade. A needle will then be inserted into
the vessel, followed by a flexible guidewire which is passed along
the vessel into the heart under x-ray guidance. The catheter is
passed over this guidewire. If the arm is the site of the
injection, a small incision is usually made over the vessel on the
opposite side of your elbow. The vessel is then punctured and the
catheter inserted.
The catheter is positioned under x-ray guidance
and by using direct blood pressure readings made through the catheter.
You may be asked to take a deep breath or
cough several times during the procedure. If you
feel you must cough at other times during the procedure, you should
tell the doctor.
A contrast medium is injected into the heart’s
blood vessels and heart chambers, so that they may be seen under
fluoroscopy (x-ray) and so permanent x-ray pictures can be taken.
When a contrast medium is injected into the coronary arteries, you
may experience chest discomfort (angina). If so, tell the
doctor immediately. When a contrast medium is injected into the
pumping chambers of the heart, you may experience a warm flushing
feeling for 30 to 45 seconds. The x-ray pictures are recorded on
videotape to provide an "instant replay," and on film,
from which a final diagnosis is made.
When the procedure is completed, the catheter
is removed, and bleeding is controlled by applying pressure at the
insertion site, using either fingers or specially designed clamps.
The total time required for the procedure including
preparation time ranges from about 60 to 90 minutes.
What information can be obtained? Detailed anatomic and functional data to assist
your physician can be obtained including:
- determination of the presence
and severity of blockages in the coronary arteries
- evaluation
of the function of the main pumping chamber of the heart
- evaluation
of the function of the heart valves
- evaluation of possible
congenital abnormalities
- assessment of damage done to
the heart and valves from
- previous heart attacks, infections,
and/or trauma
- assessment of the status of bypass surgery
- evaluation of the
function of the heart in relation to surrounding tissue
What risks are involved? Today, with the use of current techniques, cardiac
catheterization is a relatively safe procedure. However, because
a major blood vessel is punctured, bleeding can be a problem.
Bleeding usually is confined to the area around the puncture site,
and often
leaves "black and blue" marks that quickly fade. More
significant bleeding may result in a blood-filled bump that may
cause discomfort for a few days, but almost always goes away
quickly.
The catheterization laboratory team is trained
to recognize and treat any complications. All necessary drugs and
supplies are stored in the laboratory.
What happens after the procedure? You will be returned to your hospital room by
stretcher after the puncture site has been bandaged.
If the procedure was performed through the groin,
a pressure bandage may be placed on the puncture site. You will
be lying flat, keeping your leg straight. The head of the bed will
be flat or elevated slightly; it will be raised four to six hours
later. To urinate or move your bowels, you will need to use a bedpan.
If the procedure was performed through the arm,
a bulky bandage will be placed over the incision. Usually, you will
be allowed out of bed to sit in a chair and you may use the bathroom
shortly after returning to your room.
The blood pressure and pulse in your arm or leg
will be checked frequently and recorded upon your return to your
room. Fluids will be provided and you will be encouraged to drink
them so that the contrast medium with which you were injected can
be flushed out by your kidneys. Your intravenous line may be left
in place for several hours.
The bandage will be checked frequently for signs
of bleeding; but any pain, bleeding, or discomfort at the puncture
site or elsewhere in your arm or leg should be reported to the nurse
immediately.
When will I be informed of the results? The data obtained on videotape must be considered
preliminary, and serve primarily as a guide for the physician
who performed the procedure. The x-ray requires 30 to 60 minutes
for
development and processing. Review of the data takes time, and
consultation with your primary physician may be necessary. Preliminary
results
are frequently discussed at the conclusion of the procedure,
with final discussion of diagnosis and treatment plans occurring
within
12 to 24 hours. Many physicians prefer to discuss final results
during an office visit following discharge.
Conclusion We hope this information helps you better understand
what a cardiac catheterization is, what it does, and the role it
plays in maintaining your health. If you have any questions about
cardiac catheterization that your physician has not answered, please
write them down. Then be sure to discuss these questions with your
physician before you go to the hospital for your test. If you are
a hospitalized patient, be sure to ask your questions before you
are taken to the cardiac catheterization lab.
Glossary allergic: hypersensitive; a condition
in which the body reacts with an exaggerated response to a substance.
anesthetic: a medication that causes loss
of feeling or sensation, especially the sensation of pain.
antiseptic: a substance that stops the
growth of microorganisms such as bacteria and viruses.
arterial: pertaining to an artery, a vessel
that carries blood away from the heart.
blood thinners: medications that act to
prevent clotting of the blood.
blood vessel: a duct or canal that carries
blood; the arteries, capillaries and veins of the body.
cardiac: pertaining to the heart.
cardiac catheter: a flexible tube inserted
into a blood vessel to aid in the introduction or removal of fluids
into or out of the heart.
cardiac catheterization: x-ray examination
of the blood vessels of the heart after administration of a contrast
medium.
catheterization: the process of using
a catheter.
contrast medium: a dye that is used to
highlight parts of the body that do not ordinarily show up on an
x-ray.
coronary: a term used to describe vessels,
especially the arteries, of the heart.
echocardiogram: the printed record produced
by echocardiography, a procedure that measures the position and
motion of the heart by the echo obtained from sound waves penetrating
the chest.
electrocardiogram (EKG): the printed record
produced by electrocardiography, a procedure that measures the electrical
activity (or rhythm) of the heart.
fluoroscopy: a form of x-ray that lets
the physician see into your body during the examination.
intravenous: within a vein.
Please note that this information is provided for
educational purposes only. It is not intended to substitute for informed
medical advice. The user of this site should not use this information
to diagnose or treat a health problem or disease without consulting with
a qualified health care provider.
|