Cardiac catheterization

Cardiac catheterization is a technique that is used to perform several different tests and procedures. It is usually used in conjunction with other tests such as angiography and electrophysiology studies.

Cardiac catheterization is normally used to evaluate heart valves, heart function and blood supply, as well as heart abnormalities in newborns. It may also be performed to determine whether or not you may need heart surgery. As well, cardiac catheterization may be used therapeutically to repair a heart defects, open a stenotic heart valve, and open blocked arteries or heart grafts.

What is involved
A thin flexible tube called a catheter is passed through an artery or vein at the top of the leg (groin) or in the arm to reach the heart. Then X-rays are used to see the blood vessels and heart. The catheter also measures the pressure inside your heart and blood vessels and can determine if blood is mixing between the two sides of the heart.

Sometimes, a dye is injected though the catheter to see the heart and its arteries (coronary angiography). This lets your doctor see the flow of blood through your heart and blood vessels. Controlled electrical impulses may also be sent through the catheter to see how your heart reacts or to trigger irregular heartbeats (electrophysiology studies).

What to expect
You will lie on an examination table. Small metal disks called electrodes will be placed on your chest, connecting to an electrocardiogram machine that monitors your heart rhythm during the test. You will be set up with an IV (intravenous line) to give you a sedative to help you relax. The area around where the catheter will be inserted will be cleaned then an anesthetic will be used to numb the area. The catheter is then put into the artery in your leg then threaded through to your heart. You should not feel pain during this part of the test. Once the test is complete, the catheter and IV will be removed. The total time for the procedure inside the lab is between 30 minutes and an hour. After the procedure the doctor will remove the catheter from your groin area and apply pressure, using a special clamp - this will take approximately 20 minutes. You must remain on bed rest for 4 to 6 hours after the procedure. It may also involve a hospital stay of 1 to 2 nights.

How to prepare
You will probably be told not to eat or drink anything after midnight the night before your electrocardiogram (ECG). If you have diabetes, talk to your doctor about how to prepare for the test including when you should eat and take your insulin or other medications. Tell your doctor about all medications including prescription and over the counter medications that you may be taking especially blood-thinners or anti-platelet drugs. You may want to make a list of your medications and the dosages to take with you to the test. It is important to speak to your doctor about how to prepare for the test, specifically about, food, drink and medications. If you have questions, it is best to check with the centre where you are having your test for specific information about how to prepare.