Coronary angiography (coronary angiogram)

Coronary angiography, also known as a coronary angiogram, is a test for people with heart disease symptoms, such as chest pain or shortness of breath. Learn more about the test, what to expect and possible complications.

What is a coronary angiography or angiogram?

Coronary angiography is an x-ray test that uses dye to show your coronary arteries (the blood vessels that carry blood to your heart).  

It shows if any of the arteries are narrowed (smaller inside) or blocked, which can be a sign of coronary artery disease. 

The test itself is called coronary angiography, and the images it creates are called coronary angiograms.  

However, you may hear both terms used to mean the test. 

Why do I need an angiogram?

You may need to have this test done after a heart attack, or a suspected heart attack. 

You may also need an angiogram if:  

• other tests such as an electrocardiograph (ECG), exercise tolerance test or echocardiogram (echo) show that your heart muscle might not be getting enough blood  
• you have symptoms that your doctor thinks are related to blockages in the coronary arteries.  

An angiogram can help your doctor decide if you need treatment, such as medication, angioplasty or coronary artery bypass graft (CABG) surgery. 

How long does an angiogram take? 

The test usually takes a minimum of 30 minutes, but this can vary. If you have a stent put in (angioplasty), it will take longer.  

Extra time is usually needed before the test or procedure to get everything ready. 

What happens during coronary angiography?

Your doctor will place a thin, flexible tube called a catheter into a blood vessel in your arm or groin. The catheter is gently guided into the arteries near your heart.  

Coronary arteries don’t show up on normal x-rays, so a special dye called contrast is injected through the catheter to make them visible. The x-ray images show if any arteries are narrowed or blocked. The dye is not harmful.  

If a narrowed or blocked artery is found, your doctor may perform an angioplasty procedure to open it. This is when the blocked artery is opened with a small balloon. Often, a small mesh tube, called a stent, is added to keep it open.  

More about angioplasty

Sometimes your doctor may also check your heart valves, how well your heart pumps and the blood pressure inside your heart chambers.

Before the test you may need to:  

1. Let the hospital know if you take blood thinners. You may need to stop them temporarily for a few days before the test. 
2. Tell your medical team if you’ve had an allergy to x-ray contrast dye previously, or if you have other allergies.    
3. Have tests like an ECG and/or blood tests.   
4. Not eat or drink for a few hours before the test.  
5. Take your other regular medicines unless told not to. 
6. Arrange for someone to take you home afterwards.    

During the test: 

1. Your cardiologist monitors the procedure on a screen.  
2. You’ll be awake the whole time and attached to a heart monitor that records your heart rate and rhythm. If you feel unwell or have any discomfort, let your cardiology team know.  
3. You’ll lie on a hospital bed under an x-ray camera. The entry site will be cleaned and you’ll be covered in sterile (germ-free) sheets.  
4. You may be given medicine, called a sedative, to help you relax.  
5. You will be given an injection in your wrist or groin to numb the area (local anaesthetic).   
6. A small incision (cut) will be made, and a sheath (narrow tube) inserted into the artery.  
7. A catheter is passed through the sheath and guided into a coronary artery near your heart. You may feel a little pressure when this happens, but it’s usually not painful.    
8. Contrast dye is injected through the catheter. You might feel hot or flushed, but this only lasts for a few seconds.  
9. As the dye moves through your arteries, x-ray images are taken. To get clear pictures you’ll need to keep still. You may also be asked to hold your breath for a few seconds while the images are taken.
10. Once the images are taken, the catheter and sheath are removed.  

After the test: 

If the catheter was put in your wrist: a pressure band, like an inflatable bracelet, is used to stop bleeding. You’ll usually be able to sit up and walk soon after.

If the catheter was put in your groin: a tiny plug is inserted, or pressure may be applied for up to 20 minutes to stop bleeding. You’ll need to lie flat for a few hours after this.  

While you are in hospital, a nurse will regularly check your: 

• catheter site 
• blood pressure 
• pulse 
• blood flow in your arm or leg. 

You’ll be asked to drink plenty of water to help flush the x-ray dye from your system.   

Tell a nurse immediately if you feel dizzy, sweaty, have pain or notice any bleeding. 

When can I go home after an angiogram?

Most people can go home four to six hours after the test. In some cases, you may need to stay overnight.

Before you go home, a nurse will show you how to check your catheter site for any bleeding and tell you what to do if this happens.  

If your groin was the entry site, you may be advised to avoid heavy lifting, bending or straining for a week to prevent bleeding.

When can I drive?

After an angiogram, most people need to wait at least 48 hours before driving. This allows time for the effects of the medicines used during the procedure to wear off. 

You’ll need medical clearance from your cardiologist before you can drive, if: 

• your stent was placed after a heart attack or unstable angina 
• there were complications during the angiography procedure 
• you want to use a commercial or heavy vehicle licence. 

For more information, contact NZTA: phone 0800 822 422 or visit www.nzta.govt.nz 

How do I recover after an angiography?

Before your test, arrange for someone to drive you home.  

Feeling tired afterwards is normal, so rest and get plenty of sleep.   

Most people can return to normal activities, including work, within a few days. Check with your doctor before returning to work if: 

• your job involves heavy lifting  
• there were complications during the angiography  
• the test was done because of a recent heart attack.  

You may also be invited to join a cardiac rehabilitation programme to support your recovery and wellbeing.

What are the risks of a coronary angiogram?

A coronary angiogram is a very common test. Like all medical procedures and tests, it has both risks and benefits.   

Minor complications can include: 

• bleeding under the skin, which usually improves within a few days but occasionally may take a few weeks to heal 
• allergy to the contrast dye, which can cause a rash, hives or itching. Tell your cardiology team before the procedure if this has happened previously, or if you have other allergies.    

More serious complications are uncommon but can include:  

• serious bleeding – this is an emergency, call 111 
• damage to the artery in the arm or groin, possibly affecting blood supply 
• heart attack or stroke 
• kidney damage from the contrast dye  
• tissue damage from x-ray radiation if the test takes a long time 
• severe allergic reaction to the contrast dye resulting in difficulty breathing and a fall in blood pressure (medical shock) 
• risk of death. 

Your risk of complications may be higher if you:   

• are older – the older you are, the higher the risk  
• had an emergency angiogram, which means you’re unwell and there was less time to plan 
• have kidney disease, as the contrast dye can occasionally cause further damage to your kidneys 
• have a history of serious heart disease.

How is a coronary angiogram (angiography) different from angioplasty?

A coronary angiogram is the test that shows if your coronary arteries are narrowed or blocked. 

An angioplasty is a treatment that improves blood flow by using a small balloon to open the narrowed or blocked artery. A stent (small mesh tube) is often placed inside the artery to keep the artery open.  

If a narrowed artery is found during the angiogram, the angioplasty is often done at the same time.  

How is a coronary angiogram different from a CT coronary angiogram?

A coronary angiogram and a CT coronary angiogram (computed tomography coronary angiogram) are two different tests.

Unlike a coronary angiogram, a CT angiogram is a non-invasive test that uses a CT scanner and contrast dye which is given via a vein in the CT room to create detailed images of the coronary arteries.  

Unlike a conventional angiogram no catheter is inserted into an artery in your wrist or groin.

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