Coronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through your heart.

Coronary angiography is usually done in conjunction with cardiac catheterization.

Before the test starts, you will be given a mild sedative to help you relax.

An area of your body, usually the arm or groin, is cleaned and numbed with a local anesthetic. An IV (intravenous) line will be inserted into the area. A thin hollow tube called a catheter is placed through the IV and carefully moved up into one of the heart's arteries. X-ray images help the doctor see where the catheter should be placed.

Once the catheter is in place, the dye (contrast material) is injected into the IV. X-ray images are taken to see how the dye moves through the artery. The dye helps highlight any blockages in blood flow.

You should not eat or drink anything for 8 hours before the test starts. You may need to stay in the hospital the night before the test. Otherwise, you will check in to the hospital the morning of the test.

You will wear a hospital gown. You must sign a consent form before the test. Your health care provider will explain the procedure and its risks.

Tell your doctor if you are allergic to seafood, if you have had a bad reaction to contrast material in the past, if you are taking Viagra, or if you might be pregnant.

The procedure may last from 1 to several hours. You are awake during the test. You may feel some discomfort when the IV is placed into your arm and some pressure at the site when the catheter is inserted.

Occasionally, a flushing sensation occurs after the dye is injected.

After the test, the catheter is removed. You might feel a firm pressure at the insertion site, used to prevent bleeding. If the IV is placed in your groin, you will usually be asked to lie flat on your back for a few hours after the test to avoid bleeding. This may cause some mild back discomfort.

Coronary angiography is done to find a blockage in the coronary arteries, which can lead to heart attack. It may be done if you have unstable angina, atypical chest pain, aortic stenosis, or unexplained heart failure.

There is a normal supply of blood to the heart and no blockages.

An abnormal result may mean you have a blocked artery. The test can show how many coronary arteries are blocked, where they are blocked, and the severity of the blockage(s).

Cardiac catheterization carries a slightly increased risk when compared with other heart tests. However, the test is very safe when performed by an experienced team.

Generally the risk of serious complications ranges from 1 in 1,000 to 1 in 500. Risks of the procedure include the following:

• Cardiac arrhythmias
• Cardiac tamponade
• Trauma to the artery caused by hematoma
• Low blood pressure
• Reaction to contrast medium
• Hemorrhage
• Stroke
• Heart attack

Considerations associated with any type of catheterization include the following:

• In general, there is a risk of bleeding, infection, and pain at the IV site.
• There is always a very small risk that the soft plastic catheters could actually damage the blood vessels.
• Blood clots could form on the catheters and later block blood vessels elsewhere in the body.
• The contrast material could damage the kidneys (particularly in patients with diabetes).

If a blockage is found, your health care provider may perform a percutaneous coronary intervention (PCI) to open the blockage. This can be done during the same procedure.