What is cardiac catheterization?
Cardiac catheterization is performed to further evaluate coronary artery disease, valvular heart disease, congestive heart failure, and/or certain congenital (present at birth) heart conditions, such as atrial septal defect or ventricular septal defect, when other less invasive types of diagnostic tests indicate the presence of one of these conditions.
In cardiac catheterization (often called cardiac cath), a very small hollow tube, or catheter, is advanced from a blood vessel in the groin or arm through the aorta into the heart. Once the catheter is in place, several diagnostic techniques may be used. The tip of the catheter can be placed into various parts of the heart to measure the pressures within the chambers. The catheter can be advanced into the coronary arteries and a contrast dye injected into the arteries.
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The use of fluoroscopy (a special type of X-ray, similar to an X-ray "movie") assists the doctor in locating any blockages in the coronary arteries as the contrast dye moves through the arteries.
Angioplasty, percutaneous coronary intervention, and stenting may be done as part of, or following, a catheterization. Fractional flow reserve is a pressure management technique that is now commonly used in catheterization to determine the severity of an artery occlusion.
An additional technique called intravascular ultrasound (IVUS), a technique that uses a computer and a transducer that sends out ultrasonic sound waves to create images of the blood vessels, may be used during a cardiac cath. The use of IVUS provides direct visualization and measurement of the inside of the blood vessels and may assist the doctor in selecting the appropriate treatment needed in each particular situation.
A small sample of heart tissue (called a biopsy) may be obtained during the procedure to be examined later under the microscope for abnormalities.
The person will remain awake during the procedure, although a small amount of sedating medication will be given prior to the procedure to ensure the patient remains comfortable during the procedure.
Other related procedures that may be used to assess the heart include resting or exercise electrocardiogram (ECG or EKG), Holter monitor, signal-averaged ECG, chest X-ray, computed tomography (CT scan) of the chest, echocardiography, electrophysiological studies, myocardial perfusion scans, radionuclide angiography, magnetic resonance imaging (MRI) of the heart, and cardiac CT scan. Please see these procedures for additional information.
Reasons for the procedure
A cardiac catheterization may be performed to assist in the diagnosis of the following heart conditions:
Atherosclerosis. A gradual clogging of the arteries by fatty materials and other substances in the blood stream
Cardiomyopathy. An enlargement of the heart due to thickening or weakening of the heart muscle
Congenital heart disease. Defects in one or more heart structures that occur during fetal development, such as a ventricular septal defect (hole in the wall between the two lower chambers of the heart)
Congestive heart failure. A condition in which the heart muscle has become too weak to pump blood efficiently, causing fluid buildup (congestion) in the blood vessels and lungs, and edema (swelling) in the feet, ankles, and other parts of the body
Valvular heart disease. Malfunction of one or more of the heart valves that can affect blood flow within the heart
A cardiac catheterization may also be performed if you have recently had an episode(s) of one or more of the following cardiac symptoms:
Chest pain or angina
Shortness of breath
If a screening examination, such as an ECG or stress test suggests a possibility of a heart condition that needs to be explored further, a cardiac cath may be ordered by your doctor.
Other reasons for a cath procedure include evaluation of myocardial perfusion (blood flow to the heart muscle) if chest pain or angina occurs after the following:
There may be other reasons for your doctor to recommend a cardiac catheterization.
Risks of the procedure
Possible risks associated with cardiac catheterization include, but are not limited to, the following:
Bleeding at the catheter insertion site (the groin, arm, or wrist)
Blood clot or damage to the blood vessel at the insertion site
Infection at the catheter insertion site
Problems with heart rhythm (usually temporary)
Ischemia (decreased blood flow to the heart tissue), chest pain, or heart attack
Kidney damage from the cath dye
You may want to ask your doctor about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous scans and other types of X-rays, so that you can inform your doctor. Risks associated with radiation exposure may be related to the cumulative number of X-ray examinations and/or treatments over a long period of time.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor due to risk of injury to the fetus from a cardiac catheterization. Radiation exposure during pregnancy may lead to birth defects. If you are lactating, or breastfeeding, you should notify your doctor.
There is a risk for allergic reaction to the cath dye. Patients who are allergic to or sensitive to medications, contrast dye, iodine, or latex should notify their doctor. Also, patients with kidney failure or other kidney problems should notify their doctor.
For some patients, having to lie still on the cardiac catheterization table for the length of the procedure may cause some discomfort or pain.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Before the procedure
Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
You will be asked to sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if something is not clear.
Notify your doctor if you have ever had a reaction to any contrast dye, or if you are allergic to iodine.
Notify your doctor if you are sensitive to or are allergic to any medications, latex, tape, and anesthetic agents (local and general).
You will need to fast for a certain period of time prior to the procedure. Your doctor will notify you how long to fast, usually overnight.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor.
Notify your doctor if you have any body piercings on your chest and/or abdomen.
Notify your doctor of all medications (prescription and over-the-counter) and herbal supplements that you are taking.
You may be asked to withhold certain medications prior to the procedure. Your doctor will provide detailed instructions.
Notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for you to stop some of these medications prior to the procedure.
Your doctor may request a blood test prior to the procedure to determine how long it takes your blood to clot. Other blood tests may be done as well.
Notify your doctor if you have heart valve disease.
Notify your doctor if you have a pacemaker.
You may receive a sedative prior to the procedure to help you relax. If a sedative is given, you will need someone to drive you home afterwards.
Based on your medical condition, your doctor may request other specific preparation.
During the procedure
A cardiac catheterization may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices.
Generally, a cardiac catheterization follows this process:
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You will be asked to remove any jewelry or other objects that may interfere with the procedure. You may wear your dentures or hearing aids if you use either of these.
You will be asked to remove clothing and will be given a gown to wear.
You will be asked to empty your bladder prior to the procedure.
If there is excessive hair at the catheter insertion site (groin area), the hair may be clipped off.
An intravenous (IV) line will be started in your hand or arm prior to the procedure for injection of medication and to administer IV fluids, if needed.
You will be placed in a supine (on your back) position on the procedure table.
You will be connected to an ECG monitor that records the electrical activity of the heart and monitors the heart during the procedure using small, adhesive electrodes. Your vital signs (heart rate, blood pressure, breathing rate, and oxygenation level) will be monitored during the procedure.
There will be several monitor screens in the room, showing your vital signs, the images of the catheter being moved through the body into the heart, and the structures of the heart as the dye is injected.
You will receive a sedative medication in your IV before the procedure to help you relax. However, you will likely remain awake during the procedure.
Your pulses below the catheter insertion site will be checked and marked so that the circulation to the limb below the site can be checked after the procedure.
A local anesthetic will be injected into the skin at the insertion site. You may feel some stinging at the site for a few seconds after the local anesthetic is injected.
Once the local anesthetic has taken effect, a sheath, or introducer, will be inserted into the blood vessel. This is a plastic tube through which the catheter will be inserted into the blood vessel and advanced into the heart. If the arm is used, a small incision (cut) may be made to expose the blood vessel for insertion of the sheath.
The catheter will be advanced through the aorta to the left side of the heart. Fluoroscopy will be used to assist in advancing the catheter to the heart.
Once the catheter is in place, contrast dye will be injected through the catheter to visualize the heart and the coronary arteries. You may feel some effects when the contrast dye is injected into the IV line. These effects may include a flushing sensation, a salty or metallic taste in the mouth, and/or a brief headache. These effects usually last for only a few moments.
You should notify the doctor if you feel any breathing difficulties, sweating, numbness, nausea and/or vomiting, chills, itching, or heart palpitations.
After the contrast dye is injected, a series of rapid, sequential X-ray images of the heart and coronary arteries will be made. You may be instructed to take in a deep breath and hold it for a few seconds during this time.
Once sufficient information has been obtained, the catheter will be removed. The insertion site may be closed with a closure device that uses collagen to seal the opening in the artery, by the use of sutures, by using a clip to bind the artery together, or by applying manual pressure over the area to keep the blood vessel from bleeding. Your doctor will determine which method is appropriate for your condition.
If a closure device is used, a sterile dressing will be applied to the site. If manual pressure is used, the doctor (or an assistant) will hold pressure on the insertion site so that a clot will form. Once the bleeding has stopped, a very tight bandage will be placed on the site. A small sandbag or other type of weight may be placed on top of the bandage for additional pressure on the site, especially if the site is in the groin.
You will be assisted to slide from the table onto a stretcher so that you can be taken to the recovery area. NOTE: If the insertion was in the groin, you will not be allowed to bend your leg for several hours.
If the insertion site was in the arm, your arm will be kept elevated on pillows and kept straight by placing your arm in an arm guard (a plastic arm board designed to immobilize the elbow joint). In addition, a plastic band (works like a belt around the waist) may be secured around the arm near the insertion site. The band will be loosened at given intervals and removed at the appropriate time as determined by your doctor.
After the procedure
In the hospital
After the procedure, you may be taken to the recovery room for observation or returned to your hospital room. You will remain flat in bed for several hours after the procedure. A nurse will monitor your vital signs, the insertion site, and circulation/sensation in the affected leg or arm.
You should immediately inform your nurse if you feel any chest pain or tightness, or any other pain, as well as any feelings of warmth, bleeding, or pain at the insertion site in your leg or arm.
Bedrest may vary from two to six hours depending on your specific condition. If your physician placed a closure device, your bedrest may be of shorter duration.
In some cases, the sheath or introducer may be left in the insertion site. If so, the period of bedrest will be prolonged until the sheath is removed. After the sheath is removed, you may be given a light meal.
You may feel the urge to urinate frequently because of the effects of the contrast dye and increased fluids. You will need to use a bedpan or urinal while on bedrest so that your affected leg or arm will not be bent.
After the specified period of bed rest has been completed, you may get out of bed. The nurse will assist you the first time you get up, and will check your blood pressure while you are lying in bed, sitting, and standing. You should move slowly when getting up from the bed to avoid any dizziness from the long period of bedrest.
You may be given pain medication for pain or discomfort related to the insertion site or having to lie flat and still for a prolonged period.
You will be encouraged to drink water and other fluids to help flush the contrast dye from your body.
You may resume your usual diet after the procedure, unless your doctor decides otherwise.
When you have completed the recovery period, you may be discharged to your home unless your physician decides otherwise. Commonly, patients who undergo angioplasty or placement of a stent will spend the night in the hospital for careful observation. If this procedure was performed on an outpatient basis and a sedative was administered, you must have another person drive you home.
Once at home, you should monitor the insertion site for bleeding, unusual pain, swelling, and abnormal discoloration or temperature change at or near the insertion site. A small bruise is normal. If you notice a constant or large amount of blood at the site that cannot be contained with a small dressing, notify your doctor.
If your doctor used a closure device for your insertion site, you will be given specific information regarding the type of closure device that was used and how to take care of the insertion site. There may be a small knot, or lump, under the skin at the site. This is normal. The knot should gradually disappear over a few weeks.
It will be important to keep the insertion site clean and dry. Your doctor will give you specific bathing instructions.
You may be advised not to participate in any strenuous activities for a period of time after the procedure. Your doctor will instruct you about when you can return to work and resume normal activities.
Notify your doctor to report any of the following:
Fever and/or chills
Increased pain, redness, swelling, or bleeding or other drainage from the insertion site
Coolness, numbness and/or tingling, or other changes in the affected extremity
Chest pain/pressure, nausea and/or vomiting, profuse sweating, dizziness, and/or fainting
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.