Is your doctor recommending heart catheterization for your child? Dr. James A. Kuo explains some of the reasons why.

A cardiac catheterization is a diagnostic procedure that provides detailed, x-ray pictures of the heart and its blood vessels. The pictures taken with contrast dye during this procedure are called angiograms. Interventional procedures to correct problems that are found can be performed at the same time. A cardiac catheterization is performed by a specially trained cardiologist, called an interventional cardiologist. 

These procedures are performed at a hospital in a special room called the catheterization laboratory, or “cath lab.” The cath lab is equipped with an x-ray camera and a TV monitor (screen) on which the cardiologist views the child’s heart and arteries.

A pediatric or adult congenital catheterization procedure typically takes longer than an adult coronary catheterization procedure – generally about 2–3 hours. The patient is given medications for sedation by mouth or by injection prior to starting the procedure. Sometimes, an IV (intravenous line) is placed into a vein in the patient’s arm. The IV allows the patient to receive fluids and medications easily. If your child becomes anxious during the catheterization, he or she will receive more medications to help relax. 

The patient may be sedated but awake (in the “twilight”) throughout the procedure or may be completely asleep under general anesthesia, depending on the procedure to be done. After the child has relaxed, the doctor will use a small needle to inject lidocaine, a local anesthetic, to numb the areas where the vessels will be entered. This initial needle prick could be the only discomfort experienced throughout the procedure. The procedure is typically painless. The heart itself does not contain pain receptors.

The femoral vein and artery in the groin – near where the leg bends from the hip – are the vessels doctors most commonly use to insert a catheter (a flexible tube that is smaller than the vessels) and thread it through the vessels to the heart, veins and peripheral arteries to perform the procedure. Sometimes a vein under the collar bone (subclavian vein) or in the neck (internal jugular) is used. 

From this “access” point, the catheter is threaded through the veins and arteries to the heart. Because there are no nerves in the arteries, the patient will not feel the catheter or any pain during the catheterization procedure. A wide variety of specialized catheters in different sizes are available to be used for patients of all sizes – from newborn babies to adults.

The x-ray camera helps the physician guide the catheter to the heart. When the catheter is properly positioned, the cardiologist injects a contrast dye (radiographic contrast agent) through the catheter into the heart and its arteries. Most people do not feel the dye injection. However, some may feel a sensation of warmth in the chest, typically lasting only a few seconds. A few may feel lightheaded or nauseous.

When the x-ray beam passes through the dye, the arteries appear in black silhouette on a white background. The x-ray camera records a “movie” of the heart’s pumping chamber and arteries – a movie that can be recorded as a digital image or on 35mm film. This move of the heart provides critical information about the structure and functioning of the child’s heart.

The practical tips provided on the following pages can help you know how to prepare your child for a cardiac catheterization and how to care for your child once you leave the hospital.