Heart Catheterization for Congenital Heart Defects in Children

Exam Overview

A heart catheterization is a procedure used for both diagnosis and treatment of congenital heart defects.

As a test, this procedure allows doctors to see how blood flows through the heart chambers and arteries.

As a treatment, the doctor can use special tools to fix a heart defect during this procedure.

How is it done?

Before the test, your child receives medicine to make him or her relax and sleep— sedatives or sometimes general anesthesia.

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 or compression device might be used to apply pressure to the catheter site for 4 to 6 hours. If the catheter was put in your child's groin, your child will need to lie as still as possible and keep the leg straight to prevent bleeding.

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

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.
  • Closing a defect. A doctor uses the catheter to insert a small closure device into the heart. This device prevents blood from flowing between chambers. This procedure might be done to treat an atrial septal defect, ventricular septal defect, or patent ductus arteriosus.
  • 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, and shock.
  • 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.


Other Works Consulted

  • 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.


Current as of: August 31, 2020

Author: Healthwise Staff
Medical Review:
John Pope MD - Pediatrics
Martin J. Gabica MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Larry A. Latson MD - Pediatric Cardiology

Heart Catheterization for Congenital Heart Defects in Children