What Is Coronary Angiography?

Coronary angiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show the inside of your coronary arteries. The coronary arteries supply blood and oxygen to your heart.

A material called plaque (plak) can build up on the inside walls of the coronary arteries and cause them to narrow. When this happens, it’s called coronary artery disease (CAD). CAD can prevent enough blood from flowing to your heart and can lead to angina (an-JI-nuh or AN-juh-nuh) (chest discomfort or pain) and heart attack. Coronary angiography shows if you have CAD.

Most of the time, the coronary arteries can’t be seen on an x ray. During coronary angiography, a special dye is injected into the bloodstream to make the coronary arteries show up on an x ray.

To deliver the dye to your coronary arteries, a procedure called cardiac catheterization (KATH-e-ter-i-ZA-shun) is used. A long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is then threaded into your coronary arteries, and the dye is injected into your bloodstream. Special x rays are taken while the dye is flowing through the coronary arteries.

Cardiologists (doctors who specialize in heart problems) usually perform cardiac catheterizations in a hospital. You’re awake during cardiac catheterization. The procedure usually causes little to no pain, although you may feel some soreness in the blood vessel where your doctor put the catheter.

Cardiac catheterization rarely causes serious complications.

Who Needs Coronary Angiography?

Coronary angiography is a test for coronary artery disease (CAD). Your may need coronary angiography if you have signs or symptoms of CAD. These include:

• Angina. This is unexplained pain or pressure in your chest. This chest discomfort may only happen when you’re active.
• Sudden cardiac arrest. This is when your heart suddenly and unexpectedly stops beating.
• Results from an EKG (electrocardiogram), exercise stress test, or other test that suggest you have heart disease.

You also may need coronary angiography on an emergency basis if you’re having a heart attack. This test combined with a procedure called angioplasty can open the blocked artery causing the heart attack and prevent further damage to your heart.

Coronary angiography also can help your doctor decide how to treat CAD after a heart attack. This is especially true if the heart attack caused major damage to your heart, or if you’re still having chest pain.

What To Expect Before Coronary Angiography

Before having coronary angiography, discuss with your doctor:

• The test and how to prepare for it
• Any medicines you’re taking, and whether you should stop taking them before the test
• Whether you have diabetes, kidney disease, or other conditions that may require taking extra steps during or after the test to avoid complications

Your doctor will tell you exactly which procedures will be performed. For example, your doctor may recommend angioplasty if the angiography shows a blocked artery. You will have the opportunity to ask questions about the procedure, and you will be asked to provide written informed consent to have the procedures done.

It may not be safe to drive right after having cardiac catheterization. If your doctor says you can go home the same day as the test, you should arrange for a ride home from the hospital. You may have to stay overnight for this test.

What To Expect During Coronary Angiography

During coronary angiography, you’re kept on your back and awake. That way, you can follow your doctor’s instructions during the test. You’ll be given medicine to help you relax. This medicine may make you sleepy.

Your doctor will numb the area where the small plastic tube (catheter) will enter the blood vessel through a small cut in the arm, groin (upper thigh), or neck. The doctor then threads the catheter through the vessel up to the opening of the coronary arteries. Special x-ray movies are taken of the catheter as it’s moved up into the heart. The movies help your doctor see where to position the tip of the catheter.

Your doctor will put a special dye in the catheter when it reaches the correct spot. This dye will flow through your coronary arteries and make them show up on an x ray. This x ray is called an angiogram. If the angiogram reveals blocked arteries, your doctor may use angioplasty to restore blood flow to your heart.

After your doctor completes the angiography, or the angiography and angioplasty, he or she will remove the catheter from your body. The opening left in the blood vessel will then be closed up and bandaged. A small sandbag or other type of weight may be put on top of the bandage to apply pressure. This will help prevent major bleeding from the site.

The animation below shows the process of coronary angiography. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.

The animation shows the step-by-step process your doctor will follow to do a coronary angiography.

What To Expect After Coronary Angiography

After coronary angiography, you will be moved to a special care area, where you will rest and be monitored for several hours or overnight. During this time, your movement will be limited to avoid bleeding from the site where the catheter was inserted. While you recover in this area, nurses will check your heart rate and blood pressure regularly and see if there is any bleeding from the tube insertion site.

A small bruise may develop on your arm, groin (upper thigh), or neck at the site where the catheter was inserted. That area may feel sore or tender for about a week. Be sure to let your doctor know if you develop problems such as:

• A constant or large amount of blood at the site that can’t be stopped with a small bandage
• Unusual pain, swelling, redness, or other signs of infection at or near the insertion site

Talk to your doctor about whether you should avoid certain activities, such as heavy lifting, for a short time after the procedure.

What Are the Risks of Coronary Angiography?

Coronary angiography is a common medical test that rarely causes serious problems. But complications can include:

• Bleeding, infection, and pain in the arm, groin (upper thigh), or neck where the catheter was inserted.
• Damage to blood vessels. This is a very rare complication caused by the catheter scraping or poking a hole in a blood vessel as it is threaded up to the heart.
• An allergic reaction to the dye used.

Other less common complications of the test include:

• An arrhythmia (irregular heartbeat), which often goes away on its own, but may need treatment if it persists.
• Damage to the kidneys caused by the dye used.
• Blood clots that can trigger strokes, heart attacks, or other serious problems.
• Low blood pressure.
• A buildup of blood or fluid in the sac that surrounds the heart. This fluid can prevent the heart from beating properly.

As with any procedure involving the heart, complications can sometimes, although rarely, be fatal. The risk of complications with coronary angiography is higher if you have diabetes or kidney disease, or if you’re 75 years old or older. The risk for complications also is greater in women and in people having coronary angiography on an emergency basis.

Key Points

• Coronary angiography is a test that uses dye and special x rays to show the inside of your heart’s arteries (the coronary arteries). Coronary angiography can reveal any blocked or narrowed areas in your coronary arteries that might be limiting blood flow to your heart.
• To deliver the dye to your coronary arteries, a procedure called cardiac catheterization is used. Your doctor will put a thin tube (catheter) into a blood vessel in your arm, groin (upper thigh), or neck and thread it through your coronary arteries.
• You may need coronary angiography if you have signs or symptoms of coronary artery disease. You also may need coronary angiography on an emergency basis if you’re having a heart attack. This test combined with a procedure called angioplasty can open blocked arteries and prevent further damage to your heart.
• Before having coronary angiography, discuss with your doctor how to prepare for the test and any special instructions you need to follow.
• During coronary angiography, you’re kept on your back and awake. That way you can follow your doctor’s instructions during the test. You’ll be given medicine to help you relax.
• After the test is over, you will be moved to a special care area, where you will rest for several hours or overnight. During this time, your movement will be limited to avoid bleeding from the site where the catheter was inserted.
• It may not be safe to drive right after the test. If your doctor says you can go home the same day as the test, you should arrange for a ride home from the hospital.
• A small bruise may develop at the site where the catheter inserted. That area may feel sore or tender for about a week. You need to let your doctor know if you have a lot of bleeding from that area or signs of infection. You may have to avoid doing certain activities, such as heavy lifting, for a short time after the test.
• Coronary angiography is a common medical test that rarely causes serious complications. The risk of complications is higher in people who have diabetes and kidney disease, and in older people and women.

Links to Other Information About Coronary Angiography

NHLBI Resources

• Angioplasty (Diseases and Conditions Index)
• Cardiac Catheterization (Diseases and Conditions Index)

Non-NHLBI Resources

• Coronary Angiography (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)