The thin flexible tube (cardiac catheter) is usually inserted in your groin (femoral artery). Other sites that may be used are the crease of your elbow (brachial artery), your wrist (radial artery), or your neck. The catheter insertion area will be shaved and cleansed with an antiseptic solution before the test. Sterile towels will be draped over you, except for the area over the catheter insertion site.
A local anesthetic will be injected into the skin at the insertion site. A blood vessel is punctured by a special needle or exposed by making a small cut in the skin so that the catheter can be passed into the blood vessel. The catheter is slowly advanced through the blood vessel into your body. The catheter tip is moved into various positions in the heart's vessels and chambers while the doctor watches its progress on the imaging screen. Pressures within the heart chambers can be measured. Blood and heart tissue samples may also be removed through the catheter, if necessary.
You may be asked to hold your breath or move your head slightly to provide clear views of the heart and its blood vessels.
A small amount of dye (contrast material) will be injected through the catheter into your heart chamber or one of your coronary arteries. Pictures show the arteries as the dye moves through them. You may be asked to cough to help clear the contrast material out of your heart or breathe deeply and hold your breath.
It is important to lie as still as possible, since motion can make the images blurry or hard to interpret. A health professional will help you stay comfortable and will help you resist the urge to move around. Be careful not to touch the sheets or reach for your groin area because you may contaminate the sterile areas and increase the risk of infection.
Your doctor may allow you to watch the video monitor so you can see the images of your heart and coronary arteries.
You may be given nitroglycerin to help open up your coronary arteries. Or you may be given an injection of a medicine that causes the coronary arteries to narrow. You may be asked to breathe into a special mouthpiece to help measure the flow of oxygen in your circulating blood.
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