Coronary angiography 

Coronary angiography examines the blood vessels of the heart to see if they are damaged or narrowed.

Your GP will normally book you into hospital to have a coronary angiography, if you suffer from chest pain (angina). You will be referred to a cardiologist (specialist heart doctor) with training in performing angiographies.

Before you have a coronary angiography, you will attend a pre-assessment clinic, where you will be asked about your general health and if you are taking any medications for other health conditions (1).

A flexible, hollow plastic tube called a catheter is inserted into a blood vessel in your arm or leg and is guided by the cardiologist to the arteries that supply blood to the heart.

Using the catheter, the cardiologist injects a special dye that shows up on moving X-ray images (fluoroscopy) as the blood gets pumped around the heart.

The X-ray pictures are called angiograms, which help your cardiologist see how blocked your arteries are and what treatment is appropriate.

The procedure takes between twenty to ninety minutes to complete (depending on what is discovered during the test) and is often performed as a day case.

In some cases it may take longer with an overnight stay necessary, if another procedure is performed at the same time (2).

Why am I having a coronary angiography?

You may need to undergo a coronary angiography if you have experienced the following:

• Heart attack: (myocardial infarction) occurs when a coronary artery becomes completely blocked or damaged by fatty deposits (atherosclerosis). As no oxygenated blood is being carried by that specific coronary artery, the muscle begins to die. A heart attack occurs when heart muscle dies from a lack of oxygen~
• Stable angina: pain in the chest caused by a blocked artery in the heart itself. Some people with angina describe the pain as a dull, persistent ache, while other feel the pain as a tightness in the chest that may spread to the arm, neck or jaw. The pain is usually made worse during physical activity and subsides when at rest
• Unstable angina: occurs when the degree of blockage in the coronary artery becomes so severe that blood flow to the heart muscle becomes very slow. As a result, chest pain (angina) continues even when you are resting
• Aortic stenosis is a narrowing of the aortic valve in the heart. The narrowing restricts blood flow through the valve, so the heart has to work much harder to pump blood into the aorta (the largest artery in the human body) and around the body

Do I need to stop taking any of my medication?
If you take any medication for existing health conditions, you should discuss this with your nurse or doctor when you attend your pre-assessment appointment.

For example, if you take the blood-thinning medication Warfarin, you will be asked to stop taking it four days before you have a coronary angiography. Patients taking the diabetes medication Metformin should stop taking it 24 hours before the procedure (1).

What will happen on the day?
If you are going to have a coronary angiography, you should not eat anything and drink only clear fluids, such as water, black tea or coffee for six hours before the test starts (3).

Most people have the procedure done as a day case (outpatient), although others will need a short stay in hospital (3).

1. Before the procedure, you will be asked to take a shower or bath to help reduce the risk of infection. You will also be asked to shave the site of the incision (groin or arm) during this time

2. You will then be given a surgical gown to wear before you are taken to a special room called a cardiac catheterisation laboratory

3. In the laboratory, a team of medical professionals will be involved in your procedure: a specialist cardiologist; a radiographer; a technician; and a nurse

4. Your doctor will explain what will happen during the coronary angiography and any risks associated with it

5. You will then be given a mild sedative to help you relax, but you will be awake throughout the procedure. You need to be awake in order to respond to instructions given to you by the cardiologist, who may ask you cough or hold your breath for a period of time during the test

6. The catheter insertion site, usually the arm or groin, is cleaned and numbed with a local anaesthetic. A thin hollow tube called a catheter is inserted into an artery and carefully guided up into the heart. X-ray images help the doctor position the catheter in the correct position

7. When the catheter is in the correct place, a special dye is injected into catheter. X-ray images are taken to see how the dye moves through the artery and if it reveals any blockages. You may feel a hot flushing sensation (4) after the dye is injected and feel some mild pressure at the site of the catheter insertion when it is removed

Infolinks:
British Heart Foundation
Department of Health
NHS Factsheet

Refs:
1) South Devon Healthcare NHS Trust
2) Royal Berkshire NHS Trust
3) NHS Choices
4) British Heart Foundation