Exam Overview
A heart catheterization is a procedure used for both diagnosis and
treatment of
congenital heart defects. The procedure allows health
professionals to see how blood flows through the heart chambers and arteries.
This test may also be called angiography (angiogram), cardiac catheterization,
or heart cath.
To perform a heart catheterization, a thin, flexible tube called a
catheter is threaded through a blood vessel in the groin, or sometimes in
another location, and into the heart. Through the catheter, the doctor can
measure pressures, take blood samples, and inject a special dye (contrast material) into the
chambers
of the heart
or the
coronary
arteries
. The doctor watches the movement of the dye through the heart's
chambers and blood vessels.
A heart catheterization can be used to:
- See whether the structure (anatomy) of the
heart is normal.
- Measure pressures in the heart chambers and see
how the blood is flowing through the heart.
- Collect samples of
blood from inside the heart.
- Inject a dye into the heart or
arteries to see whether there are abnormal blockages in the blood vessels or
abnormalities of the heart chambers (such as defects or holes between
chambers).
- View and correct certain heart defects.
A heart catheterization usually takes between 2 and 3 hours to
complete. After the test, pressure must be applied over the catheter site for
10 to 20 minutes to stop bleeding and bruising. Then a large bandage is used to
apply pressure to the catheter site for 4 to 6 hours.
Why It Is Done
The main purpose of a heart catheterization is to view the
condition of the blood vessels in the heart.
Some procedures to correct congenital heart defects can be done
during a heart catheterization. These include:
- Septostomy. For a septostomy, an opening
is made in the wall of the heart between the upper chambers to allow blood to
mix between the heart chambers. This procedure is generally used to treat
transposition of the great vessels, tricuspid atresia,
and
hypoplastic left heart syndrome. It does not correct
the congenital heart defect but allows oxygen-rich blood to get out to the body
until surgery can be done to correct the defect.
- Closing a defect. During a heart catheterization, doctors may
use a device called a septal occluder or coil to close an
atrial septal defect,
ventricular septal defect, or
patent ductus arteriosus.
- Balloon valvuloplasty. For a balloon valvuloplasty, a small
balloon is inflated in a heart valve, widening the heart valve. This procedure
can be used to treat
pulmonary valve stenosis and
aortic valve stenosis.
- Balloon angioplasty. A balloon is inflated in an artery to
widen the artery. This procedure can be used to treat
coarctation of the aorta.
- Stents. Small wire-mesh coils (stents) can be placed in
arteries to hold them open. Stents for treatment of congenital heart defects
are often placed in arteries outside the heart, such as the pulmonary arteries
or aorta.
Results
In a child who has a congenital heart defect, a heart
catheterization shows how the blood is flowing through the heart. The exact
heart problem can be seen and sometimes treated during the same procedure or a
later procedure.
What To Think About
Major problems very rarely occur in people who have a heart
catheterization. These problems can include:
- Irregular heartbeats (arrhythmias).
- Puncture of the heart muscle or a blood vessel.
- Problems where the catheter was inserted, such as a blood clot, a
blocked artery, or an infection.
- Allergy to the X-ray dye
(allergic reactions may range from mild itching to life-threatening
situations).
- Death from bleeding, blood clots, or an allergic
reaction.
Before the test, your child receives medicine to make him or her
relax and sleep—sedatives or sometimes
general anesthesia. After the test, your child will
need to lie still for 5 to 8 hours and keep the leg in which the catheter was
inserted straight to prevent bleeding. You may need to hold your child in your
lap after the test to prevent leg movement, or your child can wear a leg board
with a Velcro strap to hold the leg still.
Complete the
medical test information form (PDF)
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to help you prepare for this test.