The typical cardiac catheterization procedure involves threading a thin tube, called a catheter, into the heart through a blood vessel. Cardiac catheters are usually placed in the arm or groin. Placement of the catheter is guided through use of an x-ray machine, and material such as iodine is used to provide contrast on the image. The procedure is used for diagnosing and evaluating certain heart conditions, such as coronary artery disease, congenital heart defects, heart failure, or problems with the heart valves.
Patients are typically asked not to eat or drink for six to eight hours prior to a cardiac catheterization procedure. The procedure requires a signed consent form witnessed by a third party. Patients should inform their doctor if they are allergic to seafood or iodine, are pregnant or might be pregnant, and if they are taking any medications, especially those for erectile dysfunction.
A trained cardiologist assisted by nurses and technicians performs the cardiac catheterization procedure. Patients are awake throughout the procedure to enable them to follow directions, but are typically given a mild sedative to help them relax. The procedure typically lasts 30-60 minutes, during which time patients are expected to remain still. Patients may experience some mild discomfort when the catheter is placed, but shouldn’t feel any severe pain.
A cardiac catheterization procedure allows physicians to perform several different types of diagnostic or evaluation tests. For example, blood samples or tissue biopsy samples can be collected from the heart through the catheter. Physicians can monitor blood pressure and blood flow through the heart chambers and in the arteries surrounding the heart, or measure oxygen levels in different areas of the heart. The arteries can also be examined for blockages.
Any type of catheterization procedure carries risks. Bleeding, infection and pain at the site of the intravenous needle injection are possible. Blood clots can form on the catheter and travel throughout the blood vessels, causing blockage in the vessels. The contrast material used could damage the kidneys, especially in patients with diabetes. A reaction to the iodine is also possible, even in those who have never been allergic to the substance.
Complications specific to the cardiac catheterization procedure include cardiac arrhythmia, bleeding, stroke, and heart attack. In rare cases, the catheter can cause damage to the blood vessels. Trauma to the artery caused by a hematoma, a type of blood clot, can also occur. Some patients may experience a drop in blood pressure. Patients should inform their physician of any severe discomfort during or after the procedure.