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What is cardiac catheterization?

Cardiac catheterization is a specialized procedure in which a long, flexible tube called a catheter is inserted into a vein or artery and guided into the heart. It’s often used instead of open-heart surgery to treat congenital heart defects (CHDs), including atrial septal defects in children and adults. It is also used to observe a fetus or child’s heart structure, measure blood pressure, expand narrowed passages, and open new passages. The experts in Boston Children’s Benderson Family Heart Center perform more than 1,500 cardiac catheterizations a year through our Division of Cardiac Catheterization. The division is the largest of its kind in the United States and trains more specialists in performing the procedure than any other hospital in the country.

When is cardiac catheterization used?

Cardiac catheterization has many different applications. For example, it is often used to treat CHDs in babies and small children for whom open-heart surgery may be very risky. It can even be performed on babies immediately after birth.

Cardiac catheterization may also be performed for the following reasons:

  • To perform valvuloplasties or angioplasties by inflating balloons in obstructed valves or vessels
  • To obtain cardiac tissue samples for biopsy
  • To open the atrial septum to alleviate certain types of CHDs that cause an infant to become cyanotic (blue skin, lips, and nail beds due to an insufficient supply of oxygen in the blood)
  • To place devices that close small holes inside the heart (such as with an atrial septal defect or ventricular septal defect), or intentionally block blood flow in a blood vessel
  • To place wire devices, called stents, in narrowed blood vessels to keep them open
  • To conduct an electrophysiologic study (EPS) or a radiofrequency catheter ablation (RFCA) procedure, which identifies the site of an arrhythmia's origin within the heart tissue (in many cases this procedure can eliminate the arrhythmia)

What happens during cardiac catheterization?

A medical illustration of a device closing the hole caused by a heart defect.

Cardiac catheterization can treat several heart conditions. It can insert a patch to close small holes caused by CHDs such as a ventricular septal defect or an atrial septal defect (shown here) or to block the overflow of blood in a vessel. It can also place a stent to open narrowed blood vessels.

A specially trained cardiologist performs cardiac catheterization. Some catheterizations are performed on an outpatient basis so the patient can go home on the same day as the procedure. Your cardiologist will tell you whether an outpatient procedure is appropriate and give details on how to prepare for a "heart cath."

First, we will give your child a sedative to help them relax and sleep during the procedure.

In the “cath lab,” your child will lie on a small table with a c-shaped X-ray machine. Heart monitors and other equipment are nearby. A specially trained staff of nurses, technicians, and physicians will monitor your child and make sure they are comfortable during the procedure.

  • Step 1: Your child will receive an injection of local anesthetic in the spot where the catheter will be inserted. Next, a thin, flexible tube (catheter) is inserted into a blood vessel, most often in the groin area.
  • Step 2: The cardiologist will use X-rays, called fluoroscopy, to help visualize the movement of the catheter as it makes its way up the vein toward the right atrium. Eventually, the tube is guided into the right ventricle, the pulmonary artery, and perhaps the right and/or left pulmonary artery branches.
  • Step 3: While the catheter is inside the heart, the cardiologist will do several things to help evaluate the heart structures, as well as the pattern of blood flow:
    • They will take blood samples from several vessels and heart chambers, which allow them to calculate heart function and flow characteristics.
    • They will take blood pressure measurements.
    • They will inject contrast fluid into the catheter and, as it flows inside the heart, take X-ray films of the path the fluid takes throughout the heart.

What happens after the test?

We will withdraw the catheter and place several gauze pads on the site to prevent bleeding. If the blood vessels in the leg were used as the insertion site, your child will be told to keep their leg straight for a few hours after the procedure to minimize the chance of bleeding.

We will then take your child to a unit in the hospital to be monitored by nursing staff for several hours after the test. You will receive written instructions regarding care of the catheterization site, bathing, activity restrictions, and any new medications your child may need to take at home.

Depending on the results of the cardiac catheterization test, we may schedule additional tests or procedures to gather further diagnostic information.

Practitioners Who Specialize In This Condition (17)

Arteriopathy

The Arteriopathy Program brings together cardiac surgeons and cardiologists along with general surgeons, pulmonologists, and other specialists.

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