What is a coronary angiogram?
A coronary angiogram is a test used to visualise the heart arteries with help of some dye and an x-ray machine. It is considered the gold standard test in the diagnosis of problems with the circulation around the heart.
How is it performed?
A coronary angiogram is often performed in a hospital setting. Prior to the procedure, the patient is offered information regarding the test and will have to sign a consent form agreeing to undergo the test.
The patient is laid on a surgical table in the angiography suite. The procedure either performed through an artery in the leg (femoral artery) or an artery in the forearm (radial artery). The skin is cleaned with an antiseptic solution and the area is covered in sterile drapes, exposing only that part through which the procedure is performed. Local anaesthetic is administered into the skin and deeper tissues around the artery and a plastic sheath is inserted once the anaesthetic has taken effect.
Through this plastic sheet is inserted the angiography wires (also called catheters) which are directed under the guidance of x-ray to the coronary arteries. Once these wires are within the coronary arteries, a dye (also called contrast) is injected through these which brighten up the coronary arteries on x-ray.
Multiple images are taken of both the right coronary artery and the left coronary system. While taking these images, the x-ray machine may move in different directions so that pictures can be taken from different angles.
Once a sufficient number of images have been taken, the wires are removed and the sheath that is present within the artery is also taken out. Tight pressure is applied onto the artery for up to 30 minutes to stop any blood from leaking out of it.
Following the procedure, the patient is observed for a short period of time and is then discharged home.
The entire procedure can take between 30 min to an hour to complete.
What information does the test provide?
Coronary angiography is an excellent test to assess the state of the coronary arteries. This is because the arteries are directly visualised while the heart is beating under the guidance of x-ray.
Risks of the procedure
The common risks include mild bleeding and bruising at the site of injection and sheath insertion. On some occasions, patients may develop an allergic reaction the contrast dye that is used in the procedure.
Sometimes, more serious complications such as heart attack or stroke may occur but these are extremely rare. Damage to the artery into which the sheath is inserted may also occur and may require treatment. There is the risk of death from the procedure as well but this is extremely rare. Studies have estimated any sort of serious complication to occur in around 1-2 in 1000 patients.
If you have any concerns, always discuss this with your doctor before going ahead with the procedure.
There are no specific limitations to coronary angiography. In some cases, access into the arteries may be a bit difficult but this is still achievable through the use of ultrasound if absolutely necessary. Furthermore there are different ports of access that can be used if required. In the case of coronary angiography, clearly the benefits of the procedure and the information obtained outweigh any risks or limitations.