What is cardiac catheterization?
A diagnostic procedure performed to detect problems with the heart and its blood supply a catheter is inserted into the body through an artery or vein. A catheter is a long thin tube through which the doctor can measure pressure or inject a contrast medium (or dye) that can be seen on fluoroscopy or x-ray. Because an iodine-related dye is injected into your bloodstream during the procedure, please advise your physician if you have a history of being allergic to shellfish, medications and/or X-ray dye. A catheterization will provide a great deal of information about your heart function. It demonstrates the heart's pumping ability, the pressure within the various heart chambers, detailed structure and flow information about the heart and blood vessels.
How long does the procedure take? Are there any other tests involved? Will I have to stay overnight in the hospital?
The catheterization itself normally takes 30 to 180 minutes; however, prior to your procedure you will need to have some blood tests, chest X-rays and an electrocardiogram (ECG) performed either the day before, or the day that the catheterization is performed. Patients do not usually have to stay overnight for the catheterization, however, an overnight stay may be warranted if your medical condition warrants it.
Will this take place in an operating room?
No, cardiac catheterization takes place in a special cardiac catheterization laboratory. This is a sterile environment (all medical personnel will wear gowns, masks and gloves), and there is equipment present which is specific to this type of procedure. Some of the specialized equipment includes an X-ray movie camera, which takes pictures of your chest from various angles; there also will be a television monitor present that will allow the doctors to see your heart as it functions. Your heart and blood pressure will be monitored throughout the procedure.
Where and how do they insert the catheter? Will I be under general anesthetic? Does it hurt?
The normal points of entry are either the groin area or the forearm. The immediate skin area is numbed with a local anesthetic, administered through a needle. You will feel an initial pin prick as the needle is inserted, and then a burning sensation as the anesthetic is injected. You also may feel pressure when the catheter itself is inserted, and/or exchanged with other catheters during the procedure.
Once the initial needle is inserted, a guide wire is passed through the needle and the needle itself is removed. Next, a small tube (catheter) is threaded over the wire and guided through the vessel and into the chambers of the heart. The doctor uses X-ray to confirm the desired location of the catheter tip, and then removes the guide wire. The catheter is connected to special equipment that records the blood pressure inside the body
You will be awake throughout the entire procedure; the physician will require your cooperation at various times during the testing, to perform certain basic functions (e.g. exhale, cough, hold your breath).
There may be a brief period of five minutes, early in the procedure, when a clear plastic hood will be placed over your head to measure the air that you exhale. This will allow the physician to determine the pumping efficiency of your heart.
There will be several periods when X-ray sensitive contrast media (dye) will be injected, through the catheter. At these moments (approximately 30 seconds to 60 seconds each) you will probably feel a warm sensation that spreads from head to toe.
Once the testing is complete, the catheter will be removed and pressure will be applied for approximately 15 minutes. You will then be taken back to your room, or to a special care area where monitoring of your heart rhythm is available.
How long does recovery take?
You will likely be allowed to go home in several hours; however, the first few hours after the procedure are very important, and you must follow the hospital staff's directions very closely.
If the point of insertion was your groin: You will be required to lay flat on your back for a minimum of four hours, once you are returned to your room. It is important that you pay careful attention to your doctor's instructions not to sit up or bend your legs, in order to minimize the chances of bleeding. After four hours, if there has not been any bleeding at the site of catheter insertion, the hospital staff will assist you in turning onto your side. You will likely be allowed out of your hospital bed in several hours.
If the point of insertion was your arm: You will be permitted to get out of bed within two hours; however, you must keep your arm straight using a stiff arm board.
The nursing staff will take your blood pressure and pulse frequently, and the site of insertion will be checked for bleeding. You also may expect the pulse and temperature of your feet to be taken, as well, to monitor the circulation. You will be encouraged to take in many fluids, first intravenously and then orally. Your first meal will be entirely liquid, and the doctors will encourage you to drink frequently in addition.
If you experience any back pain or discomfort during recovery, ask your nurse for pain medication. If you feel any pain in your chest, or see any bleeding at the point of insertion, notify the hospital staff immediately.
You should be "up and around," the day after the procedure. The first time you get out of your bed you may require assistance from a nurse, as you may feel light-headed. If there are no further complications, you will be permitted to go home several hours after the procedure.
When will we know the results of the catheterization?
Your doctor will be able to discuss the findings of the test either the same afternoon or the day after your procedure; a plan of therapy can then be discussed.
Are there noninvasive alternatives available?
While there is an excellent correlation between some of the newer techniques such as MRI (magnetic resonance imaging) and CTA (Computerized Tomographic Angiology) with the presence or absence of coronary arterial disease as well as certain anatomic abnormalities, these tests are more expensive and are used less often. Cardiac catheterization permits therapy to be delivered (this can not be done with the alternative procedures). Thus, a blockage in a coronary artery may be dealt with by angioplasty or stent at the same time. This cannot be done with MRI or CTA. MRI cannot be done in certain patients who have implanted devices, CTA delivers as much or more radiation than cardiac catheterization.
Cardiac Catheterization: A Guide for Patients, from the University of Iowa Department of Internal Medicine, The Virtual Hospital Web site.