What is a coronary angiogram?
The coronary arteries are the small blood vessels on the surface of the heart that supply the heart muscle itself with blood. A coronary angiogram is an X-ray examination of these arteries. A fine tube is guided to the heart and a small amount of contrast dye is injected, which shows up on X-ray and makes the arteries visible as a moving picture. It is the most accurate way of showing whether an artery is narrowed or blocked, and exactly where the problem is.
Why is it done?
An angiogram is usually recommended for chest pain or breathlessness that may be caused by narrowed arteries, after a heart attack, when a stress test is abnormal, or before heart valve or bypass surgery. The result determines what happens next: medication alone, a stent, or bypass surgery. In many cases, if a suitable narrowing is found, it can be treated with a stent during the same procedure.
What happens on the day?
You will be asked not to eat for a few hours beforehand, but to take most of your usual medication with a sip of water; your doctor will tell you if any tablets, such as blood thinners or diabetes medicine, must be stopped. In the catheterisation laboratory you lie on a narrow table, a drip is placed and the skin over the wrist or groin is numbed with local anaesthetic. You stay awake but relaxed. A thin catheter is passed through the artery to the heart; this is not painful, as there are no nerves inside blood vessels. When the dye is injected you may feel a brief warm flush. The test usually takes twenty to thirty minutes, and your cardiologist can often discuss the pictures with you straight afterwards.
What to expect afterwards
If the wrist was used, a tight band is left on for a few hours and you can sit up and walk soon afterwards. If the groin was used, you lie flat for a few hours to prevent bleeding. You are encouraged to drink fluids to help flush out the dye. Most patients go home the same day, though you should arrange for someone to drive you. Bruising at the puncture site is normal and fades over a week or two. Avoid heavy lifting and strenuous exercise for a few days, and contact us if the site swells rapidly, bleeds or becomes very painful, red or hot.
Possible complications
For most people an angiogram is a safe, routine test, but complications are possible. Common and minor problems are bruising, tenderness or a small lump at the puncture site. Less commonly there is significant bleeding, damage to the artery, or an allergic reaction to the contrast dye. The dye can temporarily upset kidney function, particularly if the kidneys are already weak or you are dehydrated. Serious events such as heart attack, stroke, a dangerous heart rhythm or death are rare, occurring in well under one in a thousand routine cases, and are more likely in patients who are already very ill. The X-ray radiation dose is small. Your cardiologist will explain your individual risk before you sign consent.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.