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 blood vessels. The doctor watches the movement of the dye through the heart's chambers and blood vessels.
If the doctor is also going to treat a defect, special tools are moved through the catheter into the heart. The doctor uses these tools to correct the defect. Then the tools and the catheter are removed.
A heart catheterization usually takes between 2 and 3 hours to complete. After the procedure, pressure must be applied over the catheter site for 10 to 20 minutes to stop bleeding and bruising. Then a large bandage might be used to apply pressure to the catheter site for 4 to 6 hours. Your child will need to lie as still as possible 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.
Your child might be able to go home the same day. If the procedure is more complex, your child might stay in the hospital overnight.
A heart catheterization might also be called angiography (angiogram), cardiac catheterization, or heart cath.
Why It Is Done
As a test
A heart catheterization can be used to:
See details of the heart structure.
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).
As a treatment
A heart catheterization can be used to fix certain types of heart defects. A few different types of procedures can be used during a catheterization. The type of procedure used depends on the type of defect. These procedures 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 typically 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.
Balloon valvuloplasty. A doctor uses the catheter to move a tiny balloon to the heart valve. The doctor then inflates the balloon to widen the valve. The balloon separates and stretches the valve opening. This allows blood to flow more easily through the heart.This procedure can be used to treat pulmonary valve stenosis and aortic valve stenosis.
Balloon angioplasty. A doctor uses the catheter to move a tiny balloon into a blood vessel. The balloon is inflated to widen the vessel. This procedure can be used to treat narrowed blood vessels in the lungs or coarctation of the aorta.
Stents. A doctor can use the catheter to place a small, expandable tube (stent) in an artery. The stent keeps the artery open. Stents might be placed in arteries outside the heart, such as the pulmonary arteries or the aorta.
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 one.
If your child has a complex heart defect, he or she might need a combination of surgery and catheterization to treat it.
Your child will continue to see the doctor to be sure that his or her heart is working right. Many children with a heart defect that was treated live healthy lives with few or no restrictions. Your child will need regular checkups throughout life.
What To Think About
Complications related to the catheter include:
Pain, swelling, and tenderness at the catheter insertion site.
Irritation of the vein by the catheter.
Bleeding at the catheter site.
A bruise where the catheter was inserted. This usually goes away in a few days.
Serious complications are rare, but they can be life-threatening. These complications may include:
Irregular heartbeats (arrhythmias).
Puncture of the heart muscle or a blood vessel.
Allergic reaction to the contrast material, with hives and itching and, rarely, shortness of breath, fever, andshock.
Death from bleeding, blood clots, or an allergic reaction. This is rare.
Your child might need other tests, such as an MRI or a CT scan, so that the doctor can fully understand your child's heart defect.
Feltes TF, et al. (2011). Indications for cardiac catheterization and intervention in pediatric cardiac disease: A scientific statement from the American Heart Association. Circulation, 123(22): 2607–2652.
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.