Coronary angiography

HEART (PCI Brochure)Coronary angiography is an x-ray examination of the coronary arteries, which are the tubes a few millimetres wide that lie on the outside surface of the heart and take blood to the heart muscle. Just as an engine needs petrol, the heart needs blood to do its job of pumping blood around the body. 

Slow build-up of fatty plaque within the artery wall can cause the artery to narrow, leading to reduced blood flow. Sudden changes in the plaque may cause angina (a sudden intense pain in the chest caused by momentary lack of adequate blood supply to the heart muscle) to worsen or may cause a heart attack.

During coronary angiography, a tiny plastic tube called a catheter is introduced under local anaesthesia into your wrist or groin artery. Your cardiologist watches the catheter on an x-ray screen as they pass the tip of the catheter to one of the coronary arteries that lie on the surface of your heart. A special fluid (contrast or dye) which is visible on the x-ray imaging is injected into the coronary arteries and movie pictures of the arteries are recorded. These x-ray pictures of your arteries will show any narrowings that may reduce flow of blood to your heart muscle.

Other tests performed during the coronary angiogram include measuring pressures within the heart chambers, checking function of some of the valves and checking how well the heart muscle is pumping.

Where a narrowing is identified in a coronary artery during a coronary angiogram, the cardiologist may treat the lesion using a stent (fine mesh tube). This is known as Percutaneous Coronary Intervention (PCI) also called coronary angioplasty, which means ways of opening narrowings in coronary arteries using fine tubes called catheters introduced from the wrist or groin.


The first image shows a normal Left Coronary Artery (LCA) which supplies blood to the left side of the heart. The second image shows disease (arrows) in the Right Coronary Artery (RCA) which supplies blood to the right side of the heart.

How is Coronary Angiography performed?

The procedure is conducted in an angiography suite (“cath lab”) at Intra in Epsom or North Harbour. Your interventional cardiologist will be assisted by a team of professional nurses and highly skilled medical personnel.

  • You will be awake during the procedure and may be slightly sedated.
  • A tiny plastic tube called a catheter is introduced under local anaesthesia into your wrist or groin artery. You should not feel pain at the entry site, but there still may be some non-painful sensations, such as pressure.
  • Your cardiologist watches the catheter on an x-ray screen as they pass the tip of the catheter to one of the coronary arteries.
  • A special fluid called contrast or dye that is visible on the x-ray imaging is injected into the coronary arteries.
  • Movie pictures of the arteries are recorded on the computer.

This diagnostic procedure will allow your cardiologist to determine whether there are any narrowings or blockages of the coronary arteries. Blockages may reduce the flow of blood to the heart muscle possibly leading to angina, a heart attack or reduced heart pumping action. Coronary angiography shows where and how severe the blockages are in order to plan further treatment if necessary. 

If a suitable narrowing is found in the coronary arteries, your cardiologist may then proceed to treat the lesion with percutaneous coronary intervention (angioplasty, stenting).

How should I prepare for my procedure?

  • Fasting: You may eat until 2 hours before admission then you should not have anything to  eat. You may continue to drink clear fluids.
  • Allergies or previous reactions to contrast (x-ray dye): Please inform Intra staff at the time of booking your procedure if you have any known history of allergies, particularly allergies to x-ray contrast and seafood.
  • Diabetes: If you are a diabetic you should tell the Intra staff at the time of booking. You may need to discuss your insulin dose with your cardiologist.
  • Warfarin or Coumadin: If you are taking Warfarin (a “blood thinner”) you should make this known to Intra staff at the time of booking. It is likely that you will need to stop this medication temporarily for a few days before angiography.
  • Other usual medications: Continue these unless advised otherwise by your cardiologist. In particular, please continue taking your aspirin. 

Please bring with you any medication and any recent blood test results or chest x-rays.  You may bring your favourite music on an iPod or smart phone as this can be played during the procedure. You are encouraged to bring a friend or family member.

What happens after my procedure?

  • The catheter is removed from the artery and pressure applied.
  • Your cardiologist will discuss their findings with you while you are in hospital or at a follow-up appointment.
  • After the procedures, patients are usually discharged on the same day but under some circumstances, a patient may need to stay overnight.
  • If you have treatment of a narrowing with percutaneous coronary intervention (angioplasty, stenting) you will usually be required to stay overnight.
  • If you go home on the day of the procedure, it is recommended that someone should stay with you that night.
  • You will usually be able to return to work the day after angiography but this depends in part on the result of your angiogram.
  • You should not drive on the day of the angiography procedure so you will need to have someone drive you home. You cannot go home alone in a taxi.
  • If you have percutaneous coronary intervention (PCI), the Land Transport Safety Authority (LTSA) says you should not drive for 48 hours after the intervention.

What are the risks?

Coronary angiography is a straightforward procedure and serious complications such as a heart attack(damage to heart muscle), infection and strokes are uncommon. Your cardiologist will have discussed the risks with you.

Some of the things we look out for are:

  • An allergic reaction to the x-ray contrast (dye). Rash or itching sometimes occurs, however it is extremely rare for a severe, life-threatening allergic reaction to occur.

  • A small amount of bruising and/or a small pea-sized lumber under the skin in the wrist (Radial site) or in the groin (Femoral site) is relatively common. In time this will disappear or may remain as permanent scar tissue. This is nothing to be concerned about.

  • Abnormal or irregular beating of the heart. This may occur during the procedure but is typically brief and easily treated.

  • The x-ray contrast may temporarily affect kidney function. This is more common in patients who already have have impaired kidney function and/or diabetes.

  • Serious complications such as a heart attack, damage to the heart muscle, infection, stroke and death are very rare.