What happens during an angiogram?

An angiogram typically takes from 45 minutes to one hour. As the procedure begins, a nurse inserts an intravenous line (IV) 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 performs the procedure in an area called a catheterization laboratory, or “cath lab,” that is equipped specifically for the procedure.

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, in the arm or wrist. 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 blood 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 artery in the inside of the elbow or the radial artery in the 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 passing through the blood vessels.

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. The movie is recorded as a medical digital image. (Not exactly ready for your home DVD player.)

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.