A coronary angiogram is a special type of X-ray which looks at the blood vessels of the heart. If you have angina or have had a recent heart attack you may be asked to undergo this test.
Your heart is supplied by a meshwork of blood vessels. One or more of these blood vessels can become blocked off. This block may be partial, allowing some blood to get through, or complete. The angiogram is the best test which allows the cardiologists to see exactly where these blocks occur.
Compare the blood vessels supplying your heart, to the pipes carrying water to your house. If some of the pipes are blocked you would need to know ‘which pipes and where’ before carrying out any repairs.
The cardiologists will use the information obtained from your angiogram, to decide whether you need a bypass operation, angioplasty or medical treatment.
Angiograms involve taking special X-rays. Normal X-rays would not show up blood vessels. A type of dye called ‘contrast’ is injected into the blood vessels of the heart which allows us to see them clearly.
The doctors doing the procedure will explain the risks involved in detail before asking you to consent to having this procedure. The risk of complications is very small. About one in every 500 people having an angiogram would have a complication related to the procedure.
An angiogram is done in a special laboratory called a ‘cardiac catheterization laboratory’ or ‘cath lab’ for short.
Before the test you will be expected to fast overnight or for approximately eight hours.
You will be awake during the procedure though you will not have any pain. You may be given a sedative which will help you to relax.
The catheter (a thin long length of plastic tubing) which is used to deliver the contrast ‘dye’ to the heart is inserted via a large blood vessel in the groin. You will have this area cleaned and a local anaesthetic drug will be injected into the skin so that you do not feel any pain. Once this drug has been injected you will feel pressure and ‘tugging’ at the site but no pain.
The catheter is passed through a large blood vessel in the groin or arm all the way up to the coronary arteries. You may be asked to hold your breath or cough during this procedure.
Once the operator enters the blood vessels of the heart a small amount of contrast will be injected so that the blood vessels show up on the X-rays. Rarely this may cause some discomfort in the chest.
The catheter is withdrawn from the groin (or arm) and pressure applied to the site of insertion to stop any bleeding. Your cardiologist will probably talk to you about the results of the angiogram.
Dr Nishan Wijenaike MD FRCP
Consultant Physician (Diabetes & Endocrinology)
West Suffolk Hospitals NHS Trust