For more information, visit http://www.nhlbi.nih.gov/health/health-topics/topics/ca/

What Is Coronary Angiography?

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

A waxy substance called plaque (plak) can build up inside the coronary arteries. The buildup of plaque in the coronary arteries is called coronary heart disease (CHD).

Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause chest pain or discomfort called angina (an-JI-nuh or AN-juh-nuh).

If the plaque ruptures, a blood clot can form on its surface. A large blood clot can mostly or completely block blood flow through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured plaque also hardens and narrows the coronary arteries.

Overview

During coronary angiography, special dye is released into the bloodstream. The dye makes the coronary arteries visible on x-ray pictures. This helps doctors see blockages in the arteries.

A procedure called cardiac catheterization (KATH-eh-ter-ih-ZA-shun) is used to get the dye into the coronary arteries.

For this procedure, a thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream. X-ray pictures are taken while the dye is flowing through the coronary arteries.

Cardiologists (heart specialists) usually do cardiac catheterization in a hospital. You're awake during the procedure, and it causes little or no pain. However, you may feel some soreness in the blood vessel where the catheter was inserted.

Cardiac catheterization rarely causes serious complications.

Who Needs Coronary Angiography?

Your doctor may recommend coronary angiography if you have:

Angina. This is unexplained pain or pressure in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. The pain my even feel like indigestion.
Survived a sudden cardiac arrest (SCA). This is a condition in which your heart suddenly and unexpectedly stops beating.
Abnormal results from tests such as an EKG (electrocardiogram), exercise stress test, or other test.

Coronary angiography also might be done on an emergency basis, such as during a heart attack. If angiography shows blockages in your coronary arteries, your doctor may do a procedure called angioplasty (AN-jee-oh-plas-tee). This procedure can open blocked heart arteries and prevent further heart damage.

Coronary angiography also can help your doctor plan treatment after you’ve had a heart attack, especially if you have major heart damage or if you’re still having chest pain.

What To Expect Before Coronary Angiography

Before having coronary angiography, talk with your doctor about:

How the test is done and how to prepare for it
Any medicines you're taking, and whether you should stop taking them before the test
Whether you have diseases or conditions that may require taking extra steps during or after the test to avoid complications. Examples of such conditions include diabetes and kidney disease.

Your doctor will tell you exactly which procedures will be done. For example, your doctor may recommend coronary angioplasty if the angiography shows a blocked artery.

You will have a chance to ask questions about the procedures. Also, you'll be asked to provide written informed consent to have the procedures.

It’s not safe to drive after having cardiac catheterization, which is part of coronary angiography. You’ll need to have someone drive you home after the procedure.

What To Expect During Coronary Angiography

During coronary angiography, you're kept on your back and awake. This allows you to follow your doctor's instructions during the test. You'll be given medicine to help you relax. The medicine might make you sleepy.

Your doctor will numb the area on the arm, groin (upper thigh), or neck where the catheter will enter your blood vessel. Then, he or she will use a needle to make a small hole in the blood vessel. The catheter will be inserted in the hole.

Next, your doctor will thread the catheter through the vessel and into the coronary arteries. Special x-ray movies are taken of the catheter as it's moved into the heart. The movies help your doctor see where to place the tip of the catheter.

Once the catheter is properly placed, your doctor will inject a special type of dye into the tube. The dye will flow through your coronary arteries, making them visible on an x ray. This x ray is called an angiogram.

If the angiogram reveals blocked arteries, your doctor may use coronary angioplasty to restore blood flow to your heart.

After your doctor completes the procedure(s), 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 might be placed on 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 coronary angiography.

What To Expect After Coronary Angiography

After coronary angiography, you'll be moved to a special care area in the hospital. You’ll be carefully watched for several hours or overnight. During this time, you'll need to limit your movement to avoid bleeding from the site where the catheter was inserted.

While you recover in the special care area, nurses will check your heart rate and blood pressure regularly. They’ll also watch for any bleeding at the catheter insertion site.

You may develop a small bruise on your arm, groin (upper thigh), or neck at the catheter insertion site. That area may feel sore or tender for about a week. Let your doctor know if you develop problems such as:

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

Your doctor will tell you whether you should avoid certain activities, such as heavy lifting, for a short time after the test.

What Are the Risks of Coronary Angiography?

Coronary angiography is a common medical test. It rarely causes serious problems. However, complications can include:

Bleeding, infection, and pain at the catheter insertion site.
Damage to blood vessels. Rarely, the catheter may scrape or poke a hole in a blood vessel as it's threaded to the heart.
An allergic reaction to the dye that’s used during the test.

Other, less common complications include:

Arrhythmias (irregular heartbeats). These irregular heartbeats often go away on their own. However, your doctor may recommend treatment if they persist.
Kidney damage caused by the dye that’s used during the test.
Blood clots that can trigger a stroke, heart attack, 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 be fatal. However, this is rare with coronary angiography.

The risk of complications is higher in people who are older and in those who have certain diseases or conditions (such as chronic kidney disease and diabetes).

Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. Often, these advances depend on the willingness of volunteers to take part in clinical trials.

Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions. For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you might gain access to new treatments before they’re widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don’t directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You’ll learn about treatments and tests you may receive, and the benefits and risks they may pose. You’ll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you’ll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to coronary angiography, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

Links to Other Information About Coronary Angiography

NHLBI Resources

Cardiac Catheterization (Health Topics)
Coronary Angioplasty (Health Topics)
Coronary Heart Disease (Health Topics)
"Your Guide to Living Well With Heart Disease"

Non-NHLBI Resources

Coronary Angiography (MedlinePlus)

Clinical Trials

Clinical Trials (Health Topics)
Current Research (ClinicalTrials.gov)
NHLBI Clinical Trials
NIH Clinical Research Trials and You (National Institutes of Health)
ResearchMatch (funded by the National Institutes of Health)