A cardiac catheter is a thin plastic tube that is inserted into a patient's arm, leg, or neck, and then passed through to the heart. This procedure, known as cardiac catheterization, is usually performed to determine heart health or for certain treatments. Doctors may use cardiac catheterization to diagnose suspected heart disease and evaluate existing heart problems; the procedure can also be used to unblock arteries and repair other defects. A cardiac catheter can inform doctors as to what is going on inside a patient's heart by allowing them to collect blood samples, perform biopsies on the heart muscle, measure oxygen levels, examine arteries, and measure pressure and blood flow around the heart.
Before cardiac catheterization is performed, the patient is usually given a mild sedative. The point of entry of the cardiac catheter is then cleansed and numbed with a local anesthetic. An intravenous (IV) line is then inserted and used as a guide to lead the cardiac catheter into the patient's blood vessel. From there, doctors use a special x-ray machine that produces "live" images to help them carefully guide the catheter into the patient's heart and see what is happening. The entire procedure typically lasts for 30 to 60 minutes.
Doctors inject a contrast dye in the cardiac catheter that helps them view the live x-ray images of the heart's activity. For safety reasons, patients undergoing this procedure typically should advise their doctors if they are allergic to seafood or have had allergic reactions to contrast dye or iodine in the past. They should also inform their doctors if they may be pregnant or are taking Viagra™.
Cardiac catheterization is performed in a hospital setting as either an inpatient or outpatient procedure. Patients may be advised to not eat or drink anything for six to eight hours beforehand. Some patients will need to stay at the hospital the night before their procedure is scheduled.
Heart conditions that cardiac catheterization may help doctors diagnose or evaluate include coronary artery disease, congenital heart defects, heart valve problems, heart failure, ventricular aneurysms, and heart enlargement. Cardiac catheters also assist doctors in fixing certain heart defects, such as partially closed heart valves and blocked arteries. In some cases, cardiac catheterization can help doctors detect blood vessel problems in the lungs, such as pulmonary embolisms and pulmonary hypertension.
When compared with other heart tests, cardiac catheterization carries more risk. Some of the risks include heart arrhythmias, bleeding, low blood pressure, stroke, blood vessel damage, blood clots, and heart attack. Patients usually are required to sign an informed consent form acknowledging that they are aware of these potential problems. For those under the care of experienced health professionals, however, the risk typically is minimal.