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Coronary Angiogram

What is a coronary angiogram?

A coronary angiogram is a test done to get an X-ray picture of the coronary arteries. The coronary arteries are the blood vessels that bring blood to the heart muscle.


Your healthcare provider will put a very thin, flexible tube called a catheter into a blood vessel. Your provider will then put a contrast dye into the blood vessel. The dye can be seen on X-rays and helps your provider check the inside of blood vessels. This test can show how well blood is flowing through the coronary arteries. It also can show how well your heart is pumping.

When is it used?

Your healthcare provider may do this test to look for problems in the heart's blood vessels. You may have a coronary angiogram if:

  • You have had a stress test that shows abnormal results.
  • You have chest pain.
  • You have had a heart attack.

This test helps find places where the coronary arteries may be narrowed or blocked. The results may help your healthcare provider see if you need treatment to widen an artery, remove a blockage, or bypass an artery. This test helps show if there are arteries that need surgery right away, arteries that may need surgery later, or arteries that can be treated with diet, exercise, and medicine.

How do I prepare for the test?

Before the test, your healthcare provider will want to know what medicines you are taking. If you are taking daily aspirin for a medical condition, ask your provider if you need to stop taking it before your test.


Talk with your healthcare provider about what medicines you should take before the test. Your provider may prescribe medicine to prevent blood clots from forming during the test.


Tell your provider if you have had any kidney problems or reactions to iodine-containing foods, such as seafood, or chemicals, such as X-ray contrast dye.


Follow the instructions your healthcare provider gives you. Eat a light meal the night before the test. You may be asked not to eat or drink anything for 12 hours before the test. If you have diabetes, your provider may give you special instructions about your diabetic medicine.


Arrange for someone to drive you home after the test.

What happens during the test?

This test is usually done at the hospital.


Before the test you will be given medicine to help you relax, but you will be awake during the test. You will also be given a shot of anesthetic to numb the area where the catheter will be inserted.


Your healthcare provider will put the catheter through your skin and into an artery in your groin or arm. Your provider will guide the catheter through the artery to near the opening of the left ventricle of the heart. (The left ventricle is the part of the heart that pumps oxygen-rich blood to the body.) Your provider will then guide the catheter to the coronary arteries. You will not feel the catheter as it passes through your blood vessels.


Dye will be injected through the catheter and into the arteries. Right after the injection of dye you may feel a warm or hot flush spreading over all or part of your body. This warm flush lasts only a few seconds. Sometimes the dye may make you feel like you have to urinate or have a bowel movement. This feeling also lasts only a few seconds.


X-rays are taken while the dye moves through your arteries. Sometimes the X-rays are taken so fast that they make a movie of the flow of the dye. The X-rays will show where the arteries are blocked or narrowed and how much blockage, narrowing, or deformity there is.


Your healthcare provider may then put a different catheter into the heart, record the pressures, and put dye into the left ventricle. This may be done to see how well the left ventricle is pumping.


At the end of the test, your healthcare provider will remove the catheter and put pressure on the area where the catheter was inserted (the puncture site) to control any bleeding. The test usually takes about an hour.

What happens after the test?

After the test you may stay in an observation area for at least a few hours to make sure the puncture site is not bleeding. Avoid any strenuous activity for the rest of the day to prevent bleeding. You may have a bruise near the puncture site and be uncomfortable for a few days.


Ask your healthcare provider how to take care of yourself at home. Ask about what symptoms to watch for, and what precautions you should take. Ask how and when you should expect to hear your test results. Make sure you know when you should come back for a checkup.

What are the benefits of this test?

This test finds blocked or narrowed coronary arteries. It also gives important information about how well the left ventricle of the heart is working. It helps your provider know what treatment may be best for you.

What are the risks of this test?

Complications from this test are rare. Possible risks include:

  • You may have an allergic reaction to the dye. An allergic reaction may cause hives, trouble breathing, a drop in blood pressure, unconsciousness, or swelling of the skin. This reaction can be treated with medicine.
  • The dye could damage the kidneys. If you have diabetes or kidney disease, you may have a higher risk for kidney damage.
  • The test can cause irregular heart rhythms, which might need treatment.
  • You may have bleeding where the catheter was put into your blood vessel.
  • A blood clot could form around the catheter when it is in an artery. The clot could block the artery.
  • The catheter may damage an artery.
  • In rare cases, you may have an allergic reaction to the drug used in the anesthesia.
  • While not common, a heart attack or stroke might be triggered by the test.

You should ask your healthcare provider how these risks might apply to you.

When should I call my healthcare provider?

Call your provider right away if:

  • The place where the catheter was put into your skin starts to bleed or swell, or it gets more painful.
  • Your leg or foot is painful or unusually cool.
  • You have slurred speech, balance problems, or trouble using your arm or leg.
  • You start having a rash, itching, sweating, or trouble breathing.
  • You have chest pain that is new or different from chest pain you have had before.

Call during office hours if:

  • You have questions about the test or its result.
  • You want to make another appointment.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.


HIA File diag3616.htm Release 13/2010

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