Cardiac Catheterization

What Is It?

Cardiac catheterization is a procedure in which surgeons insert a small tube (catheter) through a large blood vessel in the arm or leg, then pass the tube into the heart. Once inside the heart, doctors use the catheter to evaluate how the heart is working by measuring pressure and oxygen levels within the heart's chambers. Through the catheter, doctors also may inject a special dye that provides an X-ray image of the heart's internal structure and blood flow patterns. In some patients, the X-ray dye also is injected into the coronary arteries to identify areas that have become narrow. This procedure is called coronary angiography.

What It's Used For

Cardiac catheterization is used to evaluate patients who:

• Will be undergoing heart surgery, especially coronary artery bypass surgery
• May have suspected coronary artery disease
• Have heart valve problems, including abnormal narrowing (stenosis), leakage (insufficiency) or significant backflow of blood through a valve (regurgitation)
• May have cardiomyopathy (a specific form of heart-muscle damage)

Surgeons can use heart catheters to carry special surgical instruments into the heart. These instruments can open narrowed coronary arteries (a procedure called coronary angioplasty) or correct certain congenital (inborn) heart defects in children.

Preparation

Before the procedure, the doctor will review your medical history, your current medications and your allergy history. If you know you are allergic to X-ray dye, tell your doctor. He or she may need to switch the X-ray dye that will be used for your procedure (some newer dyes are less likely to trigger allergies) or give you medication to reduce the likelihood of an allergic reaction. Also, if there is any chance that you might be pregnant, tell the doctor before your cardiac catheterization.

Leave bracelets, necklaces and watches at home. Someone will have to drive you home from the hospital, so make arrangements beforehand. Follow your doctor's instructions for when to stop eating and drinking before your catheterization.

How It's Done

A nurse or aide will clean and shave a specific area of your arm or leg to prepare for the insertion of the catheter. In the cath lab, a special room inside a hospital, you will lie on a flat table under a large X-ray machine. Several electrocardiogram (EKG) electrodes (small metal discs) will be applied to your arms and legs. Medication will help you to relax. An intravenous (IV) line will be inserted into a vein in your arm to deliver fluids and medications.