• That blood flow to your heart is not being restricted by blockages – a finding that lets you and your doctor know your symptoms are not related to your heart; or
• That the arteries to your heart are narrowed or blocked, exactly where the blockages are located and their size, information that will enable the cardiologist to develop a treatment plan.

Having an angiogram requires a visit to a hospital to a special room called the catheterization laboratory, or “cath lab.” The cath lab is equipped with an x-ray camera and a TV monitor (screen) on which the cardiologist views your heart and arteries.

How an Angiogram Works

In this video, Dr. Mark A. Turco, Director of the Center for Cardiac and Vascular Research at Washington Adventist Hospital, performs an angiogram on a female patient with a family history of heart disease.

Your cardiologist performs an angiogram to "see" any blockages in the coronary arteries, the vessels through which blood flows to your heart muscle. To get this special view, a catheter, or small, flexible tube, is inserted into a large vessel in your upper thigh or arm, then guided through the arteries to the heart. A special “contrast” dye is injected into the catheter and to the coronary arteries and heart. This dye makes it possible for an x-ray camera to record a “movie” of your heart and its arteries. The movie, which you and your doctor may view on the TV screen, shows blood flow through the arteries of the heart – and the location of any blockages. The angiogram also provides details about the size and shape of any blockages. This information is critical. It helps the cardiologist plan the best approach for treating each blockage.

Before the Angiogram

The cardiologist will offer instructions on how to prepare for the angiogram.

• If you take medications, such as blood-thinners, consult with your cardiologist about whether you should stop taking them before the angiogram. Aspirin should be continued.
• Angiograms are generally safe. However, there are risks. Bleeding, infection and irregular heart beat can also occur. More serious complications, such as heart attack, stroke and death can occur, but they are rare.
• If you are allergic to iodine or x-ray dye, you should let your physician know. The contrast dye typically used during the angiogram procedure contains iodine. Some patients have a minor reaction to the x-ray dye, such as a skin rash or itching. The chance of a life-threatening reaction to the dye is very small. X-ray dye very rarely causes serious or permanent kidney damage, especially if kidney function was normal before it is used. However, those who have weakened kidney function, due to diabetes or high blood pressure, may face a greater risk of further deterioration in kidney function. If it occurs, the deterioration is often temporary.
• You will be asked not to eat or drink anything for several hours before the procedure.
• Your blood count, kidney function and how quickly your blood clots may be tested through blood tests.
• You will receive medications to help you relax before the procedure begins.

During the Angiogram

An angiogram typically takes from 45 minutes to one hour. As the procedure begins, a nurse inserts an IV (intravenous line) into a vein in your arm. The IV allows you to receive fluids and medications easily. If you become anxious during the angiogram, you will receive more medications to help you relax. 

During the angiogram as you lie on the table, you are mildly sedated but awake throughout the procedure. A Specially trained cardiologist, called an interventional cardiologist, performs the procedure in a specially equipped area called a catheterization laboratory, or cath lab. The temperature in the cath lab is kept low to safeguard the computers that are critical to performing the angiogram.

After you are relaxed, the doctor will use a small needle to inject lidocaine, a local anesthetic, to numb an area in the groin, or upper leg, or in the arm. This needle prick could be the only pain you will feel throughout the procedure. The procedure is typically painless.

The femoral artery in the groin – near where your leg bends from the hip – is one of the vessels doctors most commonly use to insert a catheter (a flexible tube that is smaller than the vessels) and thread it through the arteries to the heart to perform the angiogram. Instead of the femoral artery, your doctor may choose to insert the catheter in the brachial or radial artery in the inside of the elbow or wrist.

From this “access” point in your leg or arm, the catheter is threaded through the arteries to your heart. Because there are no nerves in your arteries, you will not feel the catheter or any pain during the catheterization procedure.

The x-ray camera helps the physician guide the catheter to your heart. When the catheter is properly positioned, the cardiologist injects a contrast dye (radiographic contrast agent) through the catheter into the heart and its arteries. Most people do not feel the dye injection. However, some feel minor discomfort, typically lasting only a few seconds, in their chest. A few feel lightheaded or nauseous.

When the x-ray beam passes through the dye, the arteries appear in black silhouette on a white background. If you have blockages, they appear as white areas. The x-ray camera records a “movie” of your heart’s pumping chamber and arteries – a movie that can be recorded as a digital image or on 35mm film.

By enabling the cardiologist to see blood flow and the size, shape and length of any blockages, the angiogram provides vital information for planning the best approach to treating each one.

After the Angiogram

If the angiogram shows serious blockages, the interventional cardiologist may immediately perform a coronary intervention procedure, such as balloon angioplasty and stenting, to open them and restore blood flow to your heart. Or, he or she may refer you for bypass surgery, a surgical method for restoring blood flow.

If your angiogram shows plaque build-up that does not require immediate attention, your doctor will review the pictures and study your condition in more detail before recommending a plan of action.

Care in the hospital

When the procedure is complete, the catheter is removed. To stop any bleeding, a nurse applies pressure to the point on your leg or arm at which the catheter was inserted and holds it for about 20 minutes.

After the wound is dressed, a weight (often a sandbag weighing about 10 pounds) may be placed on the wound to prevent bleeding. If the catheter was inserted in your leg, you will be asked to lie still and avoid bending your leg or lifting your head. You may need to be still for two to six hours after the catheter is removed.

Instead of using a weight to help the puncture wound stop bleeding and begin to heal properly, some physicians insert a small device at the site. The device contains materials that encourage a clot to form.

Care at home

After you return to your home, you may notice a bruise in the area where the doctor inserted the catheter. It is caused by blood that has escaped from the vessel under the skin. A small – and sometimes larger – bruise is normal. It is not necessary to report bruising to your doctor, even if the area is large. Usually, it clears up over a period of one to three weeks.

You should call the doctor if you have:

• Bleeding, drainage or painful swelling at the site where the catheter was inserted.
• Swelling or weakness and/or numbness in the leg or arm in which the catheter was inserted.