Occasionally children are born with complex birth defects of the heart or may aquire heart/lung disease later in life. When this is the case, a cardiac catheterization may be required to diagnose or fix the problem.

Dr. Kevin Hill, a pediatric cardiologist with Duke Children's, tells us more about this procedure and what to expect.

-- Dennis Clements MD, PhD, MPH

What Is a Cardiac Catheterization?

Kevin D. Hill, MD, MSA cardiac catheterization is a procedure where a thin, flexible tube called a catheter is inserted into a vein or artery and guided into the heart. The catheter can then be used to:

• Obtain blood samples and measure oxygen levels in the chambers of the heart and in the lungs
• Obtain pressure measurements from the heart chambers and in the lungs
• Inject a special dye known as contrast that can then be followed with a video x-ray (fluoroscopy) as it is pumped through the heart and lungs

Thus a catheterization provides valuable information about the structure and function of the heart, lungs, and associated blood vessels.

Cardiac catheterizations are often performed in adults, most commonly to evaluate for blockage of the coronary arteries -- the vessels that supply blood to the heart muscle.  While children occasionally require evaluation of their coronary arteries, most pediatric catheterizations are performed to evaluate and treat birth defects of the heart.

Catheterization equipment is specifically designed to accommodate the smaller size of children’s hearts and blood vessels.

Before the development of echocardiography (ultrasound of the heart), catheterization was the primary tool used for the diagnosis of heart defects in children.

While most heart lesions can now be diagnosed with an echocardiogram, catheterization is still sometimes needed to diagnose very complex heart defects. Catheterization is also important as part of the pre-operative assessment of many heart defects.

More recently catheterization has evolved to include a variety of interventional procedures including:

• Closure of holes in the heart including atrial septal defects and ventricular septal defects
• Creation of holes to improve oxygen saturations and sometimes to relieve elevated pressures (septostomy)
• Dilation of narrowed blood vessels (angioplasty)
• Opening of narrowed or occluded valves (valvuloplasty)
• Placement of stents to open up narrowed vessels
• Occlusion of unnecessary and detrimental blood vessels (embolization)
• Obtain small specimens of heart tissue for microscopic analysis (biopsy)

Recent technology has even allowed for the replacement of heart valves in the catheterization laboratory without any surgery.

How Is a Catheterization Performed?

Typically a catheterization is performed using the femoral artery and vein. These are vessels located in the leg that can be accessed from the groin region.

Other vessels that are sometimes used include the internal jugular vein located in the neck, the subclavian artery and vein located along the shoulder, and occasionally the hepatic (liver) vessels that can be accessed from the right side of the abdomen just below the ribs.

Almost all catheterizations in children are performed with sedation. Sometimes general anesthesia is used and the infant, child or adolescent is so sedated that a breathing machine (ventilator) is required to help breath during the procedure.

Sometimes less sedation is required and the child is asleep but still capable of breathing without the support of a ventilator.

Once the infant, child, or adolescent is asleep, a needle is used to access the blood vessels and a thin tube called a sheath is inserted into the vessel.

The sheath allows catheters to be passed into the vessel but prevents bleeding. Once the sheath is in place, the catheter can be navigated up into the heart and lungs.

This portion of the procedure is not painful. Catheterization does not require any surgical incision.

How Long Does It Take to Recover from a Cardiac Catheterization?

At the end of the procedure the catheters and sheaths will be removed from the body.

A nurse or physician will hold pressure over the catheterization site for about 10 minutes. This allows a clot to form and prevents any bleeding. After the clot is formed, a special dressing will be applied to the site. The dressing is designed to keep some pressure over the puncture site to prevent any further bleeding.

After four to six hours, the dressing will be removed and a smaller bandage will be left in place. Most children have recovered from the procedure within several hours. Sometimes children can be discharged home on the day of the procedure and sometimes an overnight hospital stay is required.

Occasionally, for more complicated catheterization procedures, a longer hospital stay is needed.

The catheterization site is usually fully healed within a few days. To be safe, we recommend avoiding bathing or soaking in water for three days and avoid heavy lifting (greater than 10 pounds) for 10 days.

There may be additional precautions depending on the complexity of the procedure and interventions performed.

-- Kevin D. Hill, MD, MS, is a pediatric cardiologist based at Duke University Medical Center. He also sees patients at Duke Children's Cardiology of Fayetteville.

-- Dennis Clements, MD, PhD, MPH, is the chief of primary care pediatrics at Duke Children's Hospital.