During cardiac catheterization, a catheter is inserted into a blood vessel and gently guided toward your heart. Then, tests can be done. These tests tell your doctor whether you have coronary artery disease.

During the procedure, a local anesthetic is injected where the catheter will be inserted. The anesthetic numbs the site so you won't feel pain. You will be awake during the procedure. A sheath (short tube) is put into the blood vessel at the insertion site. You may feel a little pressure, but this feeling should pass.

The catheter is inserted through the sheath. Your doctor gently guides the catheter to your heart. An x-ray video screen shows the catheter's progress. You should feel no pain as the catheter moves through the blood vessel to your heart.

X-ray contrast fluid is injected through the catheter. This allows your doctor to see the artery on an angiogram (x-ray picture). During the injection, you may be asked to hold your breath. The fluid may cause a hot flush over your body for about 10 seconds. After the injection, you may be asked to cough.

The catheter may be inserted into the artery in your arm, wrist, or groin. This is called the insertion site.