Cardiac Catheterization

If you have symptoms of heart disease, your physician may recommend a common procedure called cardiac catheterization. This test provides your physician with detailed information about your heart, heart valves and circulatory system.

Cardiac catheterization involves inserting a catheter into the heart and surrounding vessels so that your cardiologist can obtain X-ray films and pressure recordings. This procedure allows your cardiologist to examine your coronary arteries for any narrowing or blockage, assess the pumping function of your heart and evaluate your heart valves. Cardiac catheterization provides more accurate and detailed information than other diagnostic tests.

The heart

The heart is a muscle divided into four chambers. The upper two chambers are called atria, and the lower two are called ventricles. The chambers are divided by valves, which allow blood to flow from the atria to the ventricle.

Blood returns to the right atrium of the heart after it has traveled throughout the body. The right ventricle pumps the blood into the lungs, where it picks up oxygen. The blood then goes into the left side of the heart. The left ventricle pumps the oxygen-rich blood to the rest of the body, supplying oxygen and nutrients to the muscles that would die without oxygen.

Coronary arteries are blood vessels that lie on the surface of the heart. As blood leaves the left ventricle, a small amount is sent through these arteries to supply the heart’s need for blood and oxygen. If there is a complete blockage in these arteries, then the blood and oxygen cannot get through to the heart. The heart soon will start to die without oxygen. This is what is called an acute myocardial infarction or heart attack. Unlike most muscles in your body, the heart cannot repair itself.

There are two major coronary arteries: the "left" and "right." The left artery has a short segment called the left main coronary artery. It divides into two branches: the left anterior descending, which travels down the front of the heart; and the left circumflex, which circles around the left side, then to the back of the heart. The right coronary artery circles the right side and then to the back of the heart.

Cardiac catheterization risks

There is a small amount of risk involved with cardiac catheterization, and some patients experience side effects. The risks vary with each case; your cardiologist will explain these risks to you. There is less than a 1-percent chance of any side effects. The benefit of knowing the exact condition of your heart will be weighed against the risks involved.

Preparing for the catheterization

Follow these instructions unless your physician specifies otherwise:

•	Allergies — If you are allergic to X-ray contrast material, iodine or any other medications, let your cardiologist know as soon as possible.
•	Eating — Do not eat or drink anything after midnight the night before your procedure.
•	Medications — Most prescribed medicines may be taken, but make sure that your cardiologist is aware of all of your medications. If you take insulin, Glucophage, coumadin or aspirin, notify your physician. Some medications need special consideration.

If you are not already in the hospital, you will be admitted the day of the cardiac catheterization. You will need to sign a consent form giving permission to do the test. You may receive an EKG and blood tests unless you have had them recently. An IV will be started to give you fluids or medication. Before the procedure, you will be given medication that will help you relax. It is not necessary to remove your glasses, dentures or rings. Before leaving your hospital room, make sure you empty your bladder; the IV fluids and contrast material may cause your bladder to fill quickly. You will be taken to the Catheterization Laboratory (Cath Lab) by stretcher. The Cath Lab is located on the first floor of the hospital and is a part of the Diagnostic Imaging Department. Because the temperature in the Cath Lab is cool, you will be covered with blankets. A waiting room is available for your family.

After arriving in the Cath Lab, you will be asked to move onto the X-ray table. You will be lying on your back during the procedure. EKG electrodes will be placed on your chest to monitor your heart rhythm, and an automatic blood pressure cuff will be placed on your arm. A nurse or X-ray technologist will shave and cleanse the area where the catheter will be inserted. This helps to avoid infection and decrease discomfort when the tape is removed after the procedure.

The procedure

To perform the cardiac catheterization, the cardiologist inserts a small catheter into an artery in your arm or groin. First the arm or groin is scrubbed with an antiseptic solution and covered with sterile drapes. Then the cardiologist injects a local anesthetic to numb the area. This medication burns for a few seconds when it is first injected. This is usually the most painful part of the procedure.

If the arm is used, a small incision is made at the bend in your arm. The artery is then located and the catheter is inserted through a nick made in the artery. As the catheter is carefully advanced toward your heart, its progress is observed on a TV monitor.

No incision is made if the groin artery is used. A needle is inserted into the artery at the groin. A soft wire is inserted through the needle, and then the needle is removed. The catheter is slipped over the wire, and it is advanced toward the heart. Its progress is observed on a TV monitor. The lights are dimmed to make the TV picture more visible. When the catheter is in position, the wire is removed. You will not feel the catheter moving because the arteries have no nerve endings. The catheter is attached to a monitor that gives continuous blood pressure readings, and special pressure recordings may be taken in many parts of the heart. Feel free to watch the monitor and to ask questions. If you are uncomfortable or feel pain any time during the procedure, tell the cardiologist or nurse immediately.

The catheter is positioned in the aorta, and the cardiologist locates the openings of the coronary arteries. Contrast material is injected into the arteries through the catheter while X-ray pictures are taken. The lights in the room will dim while the camera is running. The X-ray camera is positioned at various angles to get different views of each artery. While the films are being taken of each artery, you will be asked to hold your breath. You should only have to hold it for five to 10 seconds; try not to bear down. When the camera stops, you may breathe normally and the lights will brighten. If you are asked to cough, give two quick, vigorous coughs. This will help clear the material from your arteries.

Next, approximately one ounce of material is injected into the left ventricle (the heart's main pumping chamber). This causes a quick hot flash throughout your body that lasts 15 to 30 seconds. X-ray films then are taken of the ventricle to evaluate its quality and pumping action. This is usually the final step of the test, and the catheter is then removed. Sometimes, however, an additional catheter may be inserted to take special pressure measurements and blood samples. It also may be used as a temporary pacemaker for the heart. Your cardiologist will explain the entire procedure.

Immediately after the test

If the catheter was inserted through an incision in your arm, the cardiologist will close the vessels and incision with a few stitches. The area will still be numb, so this will not be painful. The stitches will not have to be removed. A snug dressing is placed on the area. After this is completed, you will be taken back to your room by stretcher. It is important that you keep your elbow straight for six hours to allow the stitched area to begin healing. The entire arm does not need to be held stiff; you may move your hand and shoulder. A towel will be placed around your arm to remind you to keep the elbow straight. Although most people have little discomfort, pain medication is available. You will need to remain in bed for four hours, but you may elevate the head of your bed.

If the catheter was inserted through the groin artery, firm pressure will be applied for about 20 minutes until the artery seals itself. A pressure dressing then will be applied. You will be taken back to your room by stretcher and will be helped into bed. You must keep the affected leg straight and remain flat in bed for six to 10 hours to allow the area to heal. This may make you feel stiff, so ask for help when you first get up.

If you cough, sneeze, laugh or need to use the bedpan after your test, use you fingers to apply pressure to the dressing. If you note bleeding from the area where the catheter was inserted, apply pressure with your fingers and call your nurse immediately. A nurse will check your blood pressure, pulse and circulation frequently. You will be allowed to have fluids shortly after the procedure. If you tolerate the fluids, you will be allowed to return to your normal diet. The contrast material will cause you to urinate more frequently. By increasing your fluid intake, you will excrete the material quicker.

The results

After your catheterization has been completed, your cardiologist will study the films in detail. The information gathered from the tests will allow him to make a good analysis of your heart function. Your cardiologist will explain the results of the test to you and your family, usually within a few hours after the test’s completion. You, your family and your cardiologist will work together to form a plan of treatment. This may mean a change of medication, balloon angioplasty or bypass surgery. If you should need further treatment at another hospital, copies of your record and your X-ray films will be sent to the hospital of your choice. When your treatment is completed, the hospital will return your films to Great River Medical Center where they will become a part of your permanent medical record.

Going home

You probably will be dismissed the evening of the procedure if the catheterization yielded normal results. By this time, your blood pressure will be well stabilized, and you should be eating a normal diet. Before going home, your dressing will be removed and a bandage applied. This may be taken off the next morning. The site should be kept clean and dry. You may take a bath or shower, but do not scrub the area; just wash it gently and pat dry. Avoid strenuous activity or heavy lifting for five days. An instruction sheet will be given to you. If you have any questions, call your cardiologist's office.

If the catheter was inserted into your arm, you should be able to bend it without limitations after six hours. Avoid lifting over five pounds with that arm for one week. You should be able to feel your pulse at your wrist. If you cannot feel it, or your arm or hand becomes numb, pale or blue, notify your physician immediately. If you have any persistent or sudden bleeding, apply pressure and call your physician immediately.

If the catheter was inserted into your groin artery, you may resume light normal activities unless your physician advises otherwise. Using the leg will help relieve any stiffness you may feel. You may notice a small lump or bruise at the area where the catheter was inserted. If you should notice increased swelling, tenderness, redness or warmth, notify your physician immediately. If you have persistent or sudden bleeding, apply pressure to the area and notify your physician immediately.

Glossary of terms

•	Angina: Pain in the chest, usually due to interference with the heart's supply of oxygen. Narrowing or spasms in the coronary arteries can cause this.
•	Balloon angioplasty: A procedure similar to cardiac catheterization in which the catheter used has a special balloon at the tip. This balloon is positioned at the narrowed point in the artery and inflated for a very short time. It is re-inflated several times, resulting in widening of the narrowed area and improving the blood flow to the heart. Sometimes, balloon angioplasty can be performed instead of coronary artery bypass surgery.
•	Coronary artery bypass graft: Also called "bypass surgery." A blood vessel taken from the leg or chest is used to create a graft. One end of the graft is attached to the aorta, and the other end is sewn to the artery, beyond the blockage. This creates a detour, or bypass, that allows blood to flow freely from the aorta.
•	Coronary artery disease: A condition caused by narrowing of the coronary arteries, usually because of fatty deposits inside the arteries that cause a decreased blood supply to the heart.

For more information

If you have any questions about cardiac catheterization, please talk to your physician or call Great River Medical Center's Catheterization Laboratory at (319) 768-4840.