catheterization is used to study the various functions of the heart.
Here is a
helpful site - Cath
The purpose of cardiac catheterization is to determine whether you have
disease in your coronary arteries, and if so, pinpoint the size and location of
plaque that may have built up in your coronary arteries from
atherosclerosis. This is
generally done to determine whether you may need bypass surgery or angioplasty.
Additionally, the cardiologist can measure oxygen concentration across the
valves and walls (septa) of the heart, along with measuring pressures within
each chamber of the heart and across the valves.
Tell your doctor if you:
allergic to the iodine dye used in the contrast material or any other substance
that contains iodine. Also tell your health professional if you have asthma or
have ever had a serious allergic reaction (anaphylaxis) from any substance, such
as the venom from a bee sting.
allergic to any medications and whether you are taking any medications,
including sildenafil (Viagra). This test may require the use of nitrate
medication, such as nitroglycerin, that can cause a serious reaction if you have
taken sildenafil (Viagra) within the previous 48 hours.
any bleeding problems or take blood-thinning medication.
or might be pregnant.
kidney disease or diabetes, especially if you take metformin (Glucophage) to
control your diabetes. If you take metformin (Glucophage), your doctor will
instruct you to stop the medication 48 hours before the test. The contrast
material used during cardiac catheterization can cause kidney damage in people
who have poor kidney function. If you have a history of kidney problems, blood
tests (creatinine, blood urea nitrogen) may be done before the test to confirm
that your kidneys are functioning properly. For more information, see the
medical tests Creatinine and Creatinine Clearance and Blood Urea Nitrogen.
You will be asked to sign a consent form before the test. Consent for cardiac
catheterization is a two-step process. The first step is to consent to the
testing, or diagnostic, portion of cardiac catheterization, which includes a
coronary angiogram to evaluate the blockages in your coronary arteries. The
second step is to consent to the treatment portion, which may include a
percutaneous coronary intervention (PCI) to open your blocked arteries, based on
the results of the diagnostic portion. Talk to your health professional about
any concerns you have regarding the need for the test, its risks, or how it will
be done. Also, be sure you clearly understand what treatment will be recommended
if a blockage is found during this test. To help you understand the importance
of this test, fill out the medical test consent form.
Cardiac catheterization may be done on an outpatient basis without requiring an
overnight stay in the hospital. In this case, you should know where you have to
go and what time you need to arrive. You will need someone to pick you up after
your test because you will not be allowed to drive home yourself. Wear
You will have a physical examination, some blood tests, an electrocardiogram
(EKG), and possibly other heart tests or a chest X-ray. If you are taking any
medications, ask your doctor whether you should take them on the day of the
Do not eat or drink (except for a small amount of water) for 6 to 12 hours
before the test. You will not be put you to sleep, since it is important that you
be awake to follow instructions during the test.
Before the test, remove any necklaces, bracelets, rings, or other jewelry. You
should also remove nail polish from your fingernails and toenails to permit
observation of the blood circulation in your fingers and toes. Areas on your
arms or groin will be shaved to prepare these sites for possible insertion of
the catheter. Be sure to empty your bladder completely just before the test.
Before the procedure starts, you may want to ask for cushions or pillows to keep
you as comfortable as possible.
How It Is Done
This test is performed in the cardiac catheterization laboratory ("cath lab") by
will be asked to lie on a flat table under a large X-ray machine. Several small
metal leads (electrodes) will be attached to your legs and arms with a special
paste or gel. These leads are connected to an electrocardiogram (EKG) machine
that continuously records the electrical activity of your heart during the test.
For more information, see the medical test Electrocardiography. A device called
a pulse oximeter that measures oxygen levels in your blood and monitors your
pulse may be clipped to your finger.
A small intravenous (IV) needle may be inserted into a vein in one of your arms
to give you fluids or medications during the procedure. You may receive a
sedative medication through the IV line. This medication reduces discomfort and
will make you feel relaxed. You will remain awake during the procedure.
The location for the insertion of the cardiac catheter may be a blood vessel at
the crease of your elbow (brachial artery), wrist (radial artery), or in your
groin (femoral artery). If the catheter is to be inserted in your femoral
artery, a health professional will shave your groin area and cleanse the area
with antiseptic solution. You will then be draped with sterile towels except for
the area over the insertion site.
Next, a small amount of local anesthetic is injected into the skin at the
insertion site. A blood vessel is punctured by a special needle or exposed by
making a small incision in the skin so that the catheter can be passed into the
blood vessel. The catheter is slowly advanced through the blood vessel into your
body. The catheter tip is moved into various positions in the heart's vessels
and chambers while the doctor watches its progress on the imaging screen.
Pressures within the heart chambers can be measured, and blood and heart tissue
samples may also be removed through the catheter.
The lights are usually dimmed in the room to make it easier for the doctor to
see the images of your heart on a video monitor.
You may be asked to hold your breath or move your head slightly to provide clear
views of the heart and its blood vessels.
A small amount of contrast material will be injected through the catheter into
your heart chamber or one of your coronary arteries. Pictures show the arteries
as the dye moves through them. The table you are lying on during the procedure
may be tilted in different directions to obtain different views of your heart.
You may be asked to cough to help clear the contrast material out of your heart
or breathe deeply and hold your breath.
It is important to lie as still as possible, since motion can distort the
images. A health professional will help you stay comfortable and will help you
resist the urge to move around. Be careful not to touch the sheets or reach for
your groin area because you may contaminate the sterile areas and increase the
risk of infection.
Your doctor may allow you to watch the video monitor so you can see the images
of your heart and coronary arteries. If the images are recorded on photographic
film, you will hear the recording machine's motor, which can be noisy.
After the test
After all the necessary pictures and measurements have been taken, the catheter
will be removed. If the catheter insertion site was in your elbow, a few
stitches will be used to close the wound. If the insertion site was in your
wrist or groin, firm pressure will be applied to the area for about 10 minutes
to stop the bleeding. Then a pressure dressing will be placed over the area.
The entire procedure usually takes 1 to 2 hours, but it may take longer if
additional tests are required. The length of the test is not an indication of
the seriousness of your condition. After the test, you will be taken to an
observation room and a health professional will periodically monitor your heart
rate, blood pressure, and temperature and check for signs of bleeding at the
insertion site. The pulse, color, and temperature of the arm or leg in which the
catheter was inserted will also be checked periodically.
If your procedure was performed using your leg, you will be asked to lie in bed
with your leg extended for 4 to 12 hours, depending on the exact procedure used
and your medical condition. After that, you can move about freely, but you
should avoid strenuous activity for at least 1 to 2 day.
You should drink plenty of liquids for several hours after the test, because the
contrast material may cause you to urinate frequently. Drinking liquids will
prevent dehydration and help flush the contrast material out of your body.
Depending on the results of the test and whether any complications develop, you
may be sent home either after a 3-6-hour observation period or on the next day. If
any stitches were placed in your leg or arm, they may be removed in 5 to 7 days.