A coronary angiogram is used to see whether blood flow to and from the heart is blocked or restricted. Your doctor may ask you to have a coronary angiogram if they suspect you might have heart disease.

What are the coronary arteries?

Even though the heart is full of blood, the blood being pumped through doesn’t supply oxygen to the muscles of the heart. The heart muscles need their own supply of blood, and they get it from the coronary arteries, which wind around the outside of the heart.

If the coronary arteries become narrow, then the supply of blood to the heart muscles can slow down. If the heart muscles don’t get enough blood, it can cause problems like angina, heart failure and a heart attack.

What is a coronary angiogram?

A coronary angiogram is an x-ray during which a doctor injects radioactive dye into the coronary arteries. The dye shows up on an x-ray screen. It is also known as cardiac catheterisation or coronary angiography.

When might a coronary angiogram be necessary?

Your doctor may recommend a coronary angiogram if you have symptoms that suggest you aren’t getting enough blood to your heart, such as chest pain or a heart attack.

You might also have a coronary angiogram if you have a congenital heart defect, if you have had a significant injury to your chest or if you have problems with blood vessels elsewhere in your body. 

Preparing for a coronary angiogram

Before your appointment, prepare a list of questions to ask your surgeon, radiologist or cardiologist. 

They will talk to you, examine you and may do further tests such as blood tests, a chest x-ray and an electrocardiograph, or ECG. 

How a coronary angiogram is performed

Normally you are admitted to hospital a few hours before the procedure starts.

You will be taken to a special cardiac catheterisation laboratory or operating room, and will be asked to lie on a narrow table. The medical team will insert an intravenous line, and may give you a sedative to help you relax.

The team will inject a local anaesthetic into your groin so it is numb before making a small cut. They will then insert a catheter – a long thin tube – into an artery in your groin. Occasionally, the arm is used instead of the groin.

They will carefully thread the catheter up through the artery to your heart. Because arteries have no nerves, you should not feel this. Once the catheter is in the right spot, dye will be injected into it. You may experience a brief hot flush when the dye is inserted. 

Using x-rays, the doctors will watch the dye flow through your coronary arteries. 

If they find narrowing or blocking of the blood vessels, they may be able to treat it immediately via the catheter, such as by placing a stent to dilate and keep open the blockage. They will discuss it with you first so you can decide whether to give permission at this point.

After the procedure

The team will remove the catheter and close the cut. You will be monitored until you are ready to return to the ward.

You will need to lie flat for several hours to avoid bleeding. You might be able to go home the same day, or you might need to stay in hospital overnight. 

Once you return home, you should avoid vigorous activity for a few days. You are likely to be sore and bruised around the wound site. 

Potential risks or complications of a coronary angiogram

Generally, angiograms are very safe. However, possible risks include:

• bleeding
• pain
• heart attack
• blood clots, including stroke
• allergic reaction to the dye
• kidney damage 

Contact your doctor immediately if you have:

• bleeding
• severe pain
• signs of infection, such as swelling or fever
• chest pain 

Further information

• Read more about the heart and about staying healthy when you have a heart condition here.