Cardiac catheterization is a procedure to evaluate the health of your heart, and how it works. It is the single most accurate test to determine if you have heart disease. While there are some risks with this procedure, generally they are rare. Your doctor (Cardiologist) believes the information gained by performing a cardiac catheterization outweighs the slight risk involved. For that reason it may be recommended to you.
Cardiac catheterization involves the insertion of a thin, flexible plastic tube, called a catheter, into the body. The catheter is inserted into a vein or artery and directed through larger blood vessels toward the heart. Special x-ray equipment is used to watch the movement of the catheter inside the body.
You may often hear your doctor call a cardiac catheterization an angiogram. An angiogram is done during the cardiac catheterization procedure. An angiogram can show the degree of arterial blockage by enabling the doctor to observe the blood flow to the heart through those arteries.
During an angiogram, specially shaped catheters are inserted in sequence into the heart. They are directed toward the two opening of the coronary arteries (termed “left” and “right”). A dye is injected through the catheter into the bloodstream and x-ray pictures of the heart and coronary arteries are taken. These pictures help detect areas of narrowing (“blockages”) and assess their severity. Tilting the camera allows multiple pictures to be taken in multiple angles. This allows more detailed study of the coronary arteries.
During a left ventricular angiogram, a special catheter is directed into the left ventricle (main pumping chamber). Dye is injected under pressure into the ventricle. A series of pictures are obtained, giving a detailed view of the left ventricle when it is contracting. In patients with a leaky valve or a hole in the heart, the injection of dye inside the heart shows abnormal flow of dye in the “wrong” direction.
You will be awake during the procedure and able to watch some of the pictures on a television screen. Your cooperation will be needed during the procedure. You may be asked, for example, to hold your breath for a few seconds, to prevent blurring of the pictures. You may also be asked to cough forcefully several times, to help move the dye through your heart.
Cardiac catheterization allows doctors to assess the pumping function of the heart and to examine the coronary arteries (the blood vessels that supply oxygen-rich blood to the heart). Cardiac catheterization provides more accurate and detailed information about the function of the heart than other diagnostic tests.
Cardiac catheterization allows doctors to diagnose a number of heart conditions such as:
Coronary Artery Disease: blockages in the coronary arteries that slow down the flow of blood.
Defective Heart Valves: heart valves that do not open and close properly.
Congenital Heart Defects: deformities of the heart present at birth.
- Do not eat or drink anything after midnight the night before your procedure because you need to be fasting for at least 8 hours.
- Medications should be taken as scheduled unless special instructions are given. Do not take food or liquids with your medications. If your medications need to be taken with food/liquids, discuss your medication schedule for the testing day with your doctor.
- Be sure to mention to the doctor or nurse if you have any allergies such as allergies to x-ray dye (contrast).
- Make arrangements with a family member or friend to drive you home after the procedure–you probably will not be permitted to drive. Family members and friends can wait in an assigned area.
- Pack a small bag in case your doctor decides to keep you overnight in the hospital. You may want to include a robe, slippers, toiletries, and a book / word games (something to pass the time).
- Leave money, jewelry, and valuables at home unless a family member or friend can hold them for you during the procedure.
- Bring a list of all medications you are currently taking. Your doctor may want to continue them while you recover from your procedure.
The cardiac catheterization is usually performed as an outpatient unless you are already an inpatient. You should arrive 2 hours before your procedure. After you go through admitting, you will go to pre-op cardiac cath area. You will change into a hospital gown. An intravenous line (IV) will be started in a vein in your arm and you will be given medication to help you relax. You will be transported to the catheterization laboratory (cath lab). You will arrive to the laboratory 30 to 60 minutes before your procedure. Sometimes a scheduled procedure time must be changed due to emergencies.
Once in the cath lab, you will be transferred to a table. The cath lab is a sterile environment so the staff will be wearing hats, masks, scrubs and sterile gloves. Normally four staff are involved in performing the procedure: a physician, a nurse, a technician running the x-ray equipment, and a second technician running the computer.
The procedure is usually performed through a blood vessel in either leg, although it may also be performed through a blood vessel in the arm. The area over the blood vessel to be used (usually the right groin) will be scrubbed with a sterilizing soap and will be covered with a sterile paper drape. Do not reach on top of the drape as this can result in infection. Following the draping, local anesthetic will be injected around the vessel to numb the area. You will feel a pin prick and a slight burning sensation for 30-60 seconds. This is usually the only discomfort associated with the test.
After the area becomes numb, a needle and a small tube are inserted into the blood vessel. The catheter is then advanced to the coronary arteries and x-ray dye is flushed down the artery and filmed. This produces an x-ray “motion picture” of the blood flow through the artery and any potential blockages.
The procedure generally takes about an hour. When the test is done, the doctor removes all tubes and applies pressure to the injection site for five to 10 minutes. You will be returned to your hospital bed in most cases. However, until the blood vessel is adequately healed, you will be asked to remain in bed, usually for several hours. You can eat, drink, read, watch TV, move your arms or shift your weight. You will be instructed to not bend the leg or arm where the catheter was inserted. A weighted dressing (sandbag) will be placed over the area for a period of time.
You will be asked to get up and move around for an hour or so before you are discharged. If the puncture site looks satisfactory to the nursing staff, the IV will be removed and you will be discharged. The length of time until you are discharged depends on the doctor’s instructions, how well you are recovering, and whether or not the doctor found any blockages or abnormalities. Your doctor will discuss the results of the catheterization with you and your family before you leave the hospital.
After discharge, someone should drive you home and you should rest that evening. By the following morning, the puncture site should be healed enough to allow resumption of low-level activities. It is not unusual for a bruise or bump to develop at the puncture site. Your doctor should be contacted if the bruise extends below the knee, if the lump becomes larger than a golf-ball, or if you experience increasing pain at the puncture site.
Cardiac catheterization and angioplasty is usually not painful. You may feel some discomfort during the insertion of the catheters in the groin. There may also be some discomfort from lying perfectly still for a long time. The movement of catheters inside the blood vessels and the injection of the dye are usually painless. During the injection of the dye into the left ventricle, you will feel a warm sensation (“hot flush”) all over your body, lasting for 20 to 30 seconds. During the injection of dye into the coronary arteries, you may develop some chest discomfort. This sensation is temporary, and usually goes away within a minute or two.
There are risks to most medical procedures and this is true for cardiac catheterization. Fortunately, serious complications are rare.
A possibility (less than one in a thousand) that this procedure will cause a heart attack, stroke, or death. These occur because the catheter inside the aorta can dislodge a piece of fatty material that has built up over the years. If this material lodges in a head or heart artery, a stroke or heart attack can occur.
Less common, a blockage of the artery at the site of the catheter insertion can occur. This usually occurs in individuals with an artery severely narrowed by build up of fatty material. This may require surgical repair. On rare occasion, a total repair may not be possible and could lead to loss of a limb.
Another very rare complication is a severe, life-threatening allergic reaction to the x-ray die used in the test. This occurs approximately once in every 10,000 tests. Since 1990, a new x-ray dye has been used which greatly diminishes the risk of this type of reaction. It is important to notify your doctor or nurse of any allergies you might have.
Additionally, but rarely, a person may experience kidney impairment from the x-ray dye. This generally occurs in individuals with pre-existing kidney impairment, particularly if it is from conditions like diabetes or multiple myeloma. Normally it mild and transient, but on rare occasion it can be severe and lead to permanent kidney damage.
On extremely rare occasions, a catheter may perforate a blood vessel or heart chamber, which can be fatal, or may require emergency operation.
Also, on extremely rare occasions, excessive blood loss from the catheter insertion site may require a transfusion.
It is important that you know about these risks, but you should not be alarmed. Cardiac Catheterization is widely considered a safe, virtually painless procedure for viewing the heart and associated blood vessels.