Cardiac Angiography (Diagnostic Heart Cath)
What Is Cardiac Catheterization?
Cardiac catheterization is a diagnostic procedure that involves the insertion of a
catheter (a long, thin, flexible tube) into the heart. The catheter is introduced into
the body through a vein or artery, usually in the leg, and guided by the doctor toward
the heart. The doctor uses special x-ray equipment to monitor the progress of the
catheter as he maneuvers it through the vein or artery toward the heart.
Once the catheter is inside the heart, the doctor is able to position it and inject
dye into the chambers and vessels of the heart. When viewed with the special x-ray
equipment, this dye allows the doctor to see the pumping action of the heart, the
function of the heart valves, and the blood flow in the coronary arteries, which supply
oxygen-rich blood to the heart muscle.
Other terms may be used to describe cardiac catheterization. These terms include
coronary angiography, angiogram, and cardiac (or heart) cath.
Why Is Catheterization Important?
Cardiac catheterization allows the doctor to see the heart as it pumps blood. He
is able to view the expansion and contraction of the chambers of the heart; the
opening and closing of the heart valves; and the flow of blood through the coronary
As compared to other diagnostic tests, cardiac catheterization provides more
accurate and detailed information. This is especially important when visualization
of the coronary arteries is required. This test provides the doctor with a picture
of the arteries of the heart and allows him the assess the presence, location, and
degree of severity of blockages in the coronary arteries. This information will allow
the cardiologist to chose the best treatment for you.
The Uses Of Catheterization
Cardiac catheterization enables doctors to diagnose a number of common heart
Coronary Artery Disease
The inside walls of arteries are normally smooth and flexible, allowing blood to
flow through them easily. With time, fatty deposits may accumulate on the inside of
an artery’s wall, causing it to become plugged.
As the build up of fatty deposits on the interior of the arteries continues, the
opening of the arteries narrows with the result being a reduction in the flow of
blood. When blockages occur in the coronary arteries, symptoms of angina (chest pain
or discomfort) may result. Severe blockages may even cause a heart attack.
If your doctor suspects you have coronary artery disease, a cardiac
catheterization is often recommended. During the heart catheterization, the x-ray
dye is injected into the coronary arteries. Pictures taken show the flow of blood
through the coronary arteries. Actual blockages will appear as areas where the
vessel is pinched, resulting in a dramatic reduction of blood flow. The x-ray
pictures allow the doctor to identify the points where blockage of the coronary
vessels is present and evaluate the severity of the blockage.
Defective Heart Valves
The heart valves keep the flow of blood moving through the heart in one direction
by opening and closing in sequence with the contraction of the heart muscle. When
valve disease is present, one or more of the heart valves do not work properly. The
valve may be "narrowed," which limits the ability of the chamber of the heart to fill
completely, or the valve may "leak," which allows some blood to back up against the
normal direction of flow.
Most valve defects are mild and have little effect on the pumping function of the
heart. However, some defects become progressively worse and may cause weakening of
Heart catheterization allows the cardiologist to see the operation of the heart
vales and monitor the flow of blood through the heart. This allows the doctor to
confirm the diagnosis of heart valve disease and measure the severity of a valve’s
narrowing or leakage.
Congenital Heart Defects
A congenital heart defect is a deformity of the heart that is present at birth.
Common examples of congenital heart defects include an abnormal hole between heart
chambers, or a narrowed valve.
When congenital heart defects are severe, the pumping action of the heart may be
compromised, limiting its efficiency in delivering oxygen-rich blood to the body.
Some congenital heart defects make the heart work harder to compensate for the
deformity, which, with the passage of time, causes the heart to weaken and decrease
Cardiac catheterization is often used to confirm the diagnosis of congenital
heart defects and to assess the extent of the problem.
Preparing For A Catheterization
In some instances, the decision to perform a heart catheterization may be made
while you are hospitalized. In other cases, you may go to the hospital specifically
for the heart catheterization procedure, generally arriving at the hospital in the
morning on the day of the procedure. In those instances where you know in advance
that you are going to undergo a heart catheterization, there are a number of things
you can do to prepare for the procedure:
- Generally, you should not eat or drink anything for 6-8 hours before the procedure. This will minimize the chance of an upset stomach during the test. Small sips of water to swallow your medications are fine.
- Make arrangements to have a family member or friend drive you home after the procedure.
- Bring an "overnight bag" in case the doctor keeps you overnight in the hospital. A robe, slippers, pajamas or nightgown, and toiletries are recommended.
- Bring a list of all medications you are currently taking. Be sure to include the exact names and dosages.
- Mention to the doctor if you are allergic to x-ray dyes (contrast media).
Several routine tests will be performed before the procedure, including an ECG and
blood tests. For your convenience, these tests may be done one or two days prior to
the heart catheterization.
In preparation for the procedure, the area where the catheter will be inserted is
cleaned and shaved. This makes it easier for the cardiologist to insert the catheter
and minimizes the risk of infection. Usually, the preferred site for placing the
catheter is the groin; however, in some cases, the crease of the arm is used.
Empty your bladder as completely as possible before the test starts. (A bedpan or
urinal will be available during the procedure). Generally, you’ll be allowed to wear
your dentures, hearing aids, and eyeglasses during the procedure. A small intravenous
needle ("IV line") is inserted into a vein in your arm so that medications may be
injected directly into the vein, if needed. A sedative will be given to help you
What Is A Cardiac Catheterization Lab Like?
Cardiac catheterization is performed in a specially equipped x-ray room, called a
cardiac catheterization laboratory, or simply "cath lab". Since you will be mildly
sedated, you will be taken to the cath lab on a movable bed. Once in the cath lab,
you will be transferred to a special x-ray table and draped with sterile sheets. The
cath lab has a large x-ray camera above the table, several television screens showing
views from the x-ray camera, heart monitors, and other special equipment.
The cath lab team generally includes a cardiologist, an assistant, a nurse, and
one or two technicians. It is important to the cath lab team that you be comfortable
throughout the procedure, so be sure to let them know of any concerns you may have.
You will need to keep your legs and arms as still as possible during the procedure.
During The Heart Cath Procedure
The area where the catheter will be inserted is cleansed thoroughly. A tiny needle
is used to inject a local anesthetic into the skin at the site where the catheter
will be inserted. This numbs area to minimize discomfort during the procedure. The
injection may cause a mild stinging sensation.
Once the area is numb, a small incision is made in the skin. A needle is inserted
in the blood vessel into which a sheath (a small tube) will be inserted. The
cardiologist will place the various catheters through this small tube during the
After insertion into the blood vessel, the catheter is carefully guided toward the
heart. The television screen connected to the x-ray camera allows the doctor and
staff to follow the progress of the catheter.
What Does It Show?
Once the catheter is in place inside the heart, the cardiologist is able to assess
the function of the heart in several ways. The pressures inside the heart can be
measured and x-ray dye injected into the heart chambers and coronary arteries.
Pressure readings taken inside the heart allows the doctor to assess the heart’s
pumping function and estimate the severity of valve defects. Monitor screens in the
cath lab display the pressure readings. These readings may also be recorded on
special tracing paper.
Pictures taken of the blood flow through the coronary arteries are called
coronary angiograms. Specially shaped catheters are placed into the heart, one after
the other. The special shape of these catheters allows the x-ray dye to be directed
toward the openings of the coronary arteries. Once in position, the x-ray dye is
injected through the catheter into each coronary artery. The x-ray camera takes
pictures. These pictures reveal blockages in the coronary arteries and show their
impact upon blood flow.
When the doctor takes pictures of the heart’s main pumping chamber (the left
ventricle), the procedure is called a left ventriculogram. A special catheter is
maneuvered into the left ventricle. Then, x-ray dye is injected under pressure into
the left ventricle. A series of pictures are taken to view the left ventricle during
its pumping action.
When a leaky valve or a hole in the heart is present, the x-ray dye inside the
heart shows abnormal flow of dye going in the "wrong" direction.
During the heart catheterization, the x-ray camera is tilted at various angles
to obtain the best views of the coronary arteries and heart chambers.
What Is It Like To Have A Heart Catheterization?
Although you will be mildly sedated, you will be awake during the procedure.
Cardiac catheterization usually is not painful; however, you will experience some
You will feel a stinging or burning sensation when the groin area is anesthetized.
Some pressure may also be felt in the area when the sheath is placed. You will not
feel the catheters moving through the blood vessels and into your heart. When x-ray
dye is injected into the coronary arteries, you may feel some tingling or
discomfort; however, this sensation subsides in seconds. The injection of dye into
the left ventricle causes a warm sensation ("hot flash") over your body, lasting for
A complete cardiac catheterization study generally lasts about one hour. Lying
still on the x-ray table for this period of time may be uncomfortable. The staff will
do their best to help you stay comfortable throughout the procedure.
After Cardiac Catheterization
Once the procedure is completed and the catheters are removed, firm pressure is
applied over the insertion site for 10-20 minutes. This is to stop the bleeding from
the arterial site.
You will be taken back to your room or the recovery area. A pressure device will
be applied to the insertion site. For a period of time, usually four to six hours,
you will lie flat in bed, to allow the puncture in the artery to form a seal. During
that time, do not bend or lift the extremity where the catheters were inserted. To
relieve stiffness, you may move your foot or wiggle your toes. You may bend the other
leg at the knee to relieve stress on your back.
The nurse will check your pulse and blood pressure frequently, and will also keep
checking the site where the catheters were inserted. If you feel sudden pain at the
site, or if you notice a warm, sticky sensation of fluid, notify the nurse
You will be able to eat shortly after returning to your room. You will be given
fluid through an I.V. or asked to drink plenty of liquids to "flush" the x-ray dye
out of the body.
The doctor who performed the study may be able to discuss with you some of the
results soon after the test. A complete, detailed analysis of all the findings will
take more time.
As You Recover From Heart Catherization
- Limit your activity during the first 24 hours after the procedure. Once you return home, you can move about, but do not strain or lift heavy objects for a few days.
- If you notice new blood on the dressing, place your fingers over the site and press firmly for about 20 minutes. If bleeding continues, call your doctor or go to the nearest emergency room while continuing to apply pressure.
- Leave the dressing over the insertion site in place until the day after the procedure. You will be instructed on how to take it off and when it’s OK to take a shower.
- A bruise or swelling under the skin at the insertion site is common. These generally disappear within three to four weeks.
- Call the doctor if the insertion site becomes painful or warm to the touch, or if it shows signs of infection.
- The doctor will tell you when you can return to your normal activities, and whether there are any specific restrictions.
- The doctor may prescribe medications after the procedure or adjust the medications you were taking before the heart cath. Be sure to follow his instructions.
Is Catheterization Safe?
Cardiac catheterization is an "invasive" procedure that requires the insertion of a
catheter into the body. Therefore, the procedure has a small level of risk. Thanks to
modern equipment and techniques, heart catheterization is considered a relatively safe
Most complications associated with cardiac catheterization are minor and of no
long-term consequence. These include nausea and vomiting, allergic skin rash (hives),
and heartbeat irregularity. Some patients may bleed at the insertion site. If blood
collects under the skin, swelling and/or a "bruise" may develop.
Less frequently, catheterization may be associated with more serious complications.
These include damage to blood vessels, formation of blood clots, infection, abnormal
heart rhythms, a heart attack, or a stroke. Fatalities are extremely rare.
Most patients who undergo catheterization do not experience complications.
Nonetheless, you should be aware of the risks of the procedure. Be sure to ask you
doctor about any special risks that apply to you.
In most cases, the benefits of cardiac catheterization far outweigh the risks.
Catheterization provides important information about the heart’s pumping function
and the condition of the coronary arteries and heart valves. This information often
cannot be obtained by any other means. It allows the doctor to make an accurate
diagnosis and begin treatment before irreversible damage to the heart occurs.