What is cardiac catheterization?
A cardiac catheterization—also called a cardiac cath or heart cath—is a test to check your heart and coronary arteries—specifically, blood flow in the coronary arteries, and blood flow and blood pressure in the chambers of the heart. This test can show how well the heart valves work, as well as check for any defects in the way the wall of the heart moves.
The test, called an angiography, is performed in Tanner’s cardiac catheterization laboratory ("cath lab") by a cardiologist. By injecting a small amount of dye through a catheter into your heart chamber or one of your coronary arteries, the cardiologist is able to get images of the arteries as the dye moves through them.
Why did your doctor request a cath test?
Your doctor ordered a cardiac catheterization to find out if you have disease in your coronary arteries (atherosclerosis). This test is also used to diagnose anatomical problems, like valvular problems, deformities in the heart muscle and arrhythmia. If you have atherosclerosis, this test can pinpoint the size and location of fat and calcium deposits (plaque) that are narrowing your coronary arteries. Results from cardiac catheterization help determine what treatments, such as angioplasty or stenting, may be effective for you to open blocked valves.
Cardiac catheterization is also done to:
- Check the pumping action of the heart
- Find out if there is a congenital heart defect (a heart problem you may have been born with)
- Check blood flow through the heart after surgery
- Find out how well the heart valves work
How a cath test is done
Cardiac catheterization (“cath”) uses a catheter – a thin, hollow, flexible tube – inserted into the artery of the groin or arm. Using X-rays, the tip of the catheter is guided to the heart and allows your doctor to see an angiogram, or movie, of the heart and blood vessels by injecting a dye through the catheter. This helps the doctor see your coronary arteries at work. The dye or contrast material helps your doctor take X-ray pictures of your heart.
Intravenous (“IV”) medicines are used to relax you. Let your patient care team know if there is any discomfort during the procedure. The goal is to keep you extremely comfortable and relaxed without being put to sleep. You will be given a local anesthetic to numb the area where the catheter will be inserted.
A thin flexible wire is then inserted through a needle. This is known as a guide-wire because it helps guide catheters. The needle is then removed and the sheath or tube is left in the artery to allow your doctor to perform the test.
A cardiac cath is a relatively safe procedure. Occasionally, patients have a rash as an allergic reaction to the contrast material. Other infrequent complications can include bleeding that requires blood transfusion or surgical repair, blood clots and a sustained abnormal cardiac rhythm. Rare serious complications can include death, a heart attack, stroke and need for emergency surgery. Tanner has taken precautions to minimize the risk of all adverse side effects and has implemented procedures to handle such effects as safely as possible.
Sometimes performed during cardiac catheterization, an intravascular ultrasound calls for a transducer to be threaded into the cardiac arteries through a catheter in the groin. This test can provide detailed information about the atherosclerosis (a hardening of the arteries) inside the blood vessels.
After the test, the catheter will be removed from the insertion site. To prevent bleeding, the site may be closed using pressure or a closure device. After the test, a Tanner health professional will periodically monitor your heart rate, blood pressure and temperature and check for signs of bleeding at the insertion site. If the catheter was inserted in your leg, you may have to lie still with your leg extended for several hours, depending on the procedure used and your medical condition.
How do I prepare?
Do not eat or drink after midnight. Medicines prescribed by your doctor may be taken with sips of water. If the procedure is scheduled for the afternoon, you may be allowed to have an early liquid breakfast (juice, tea, brother, water, etc.) prior to 7 a.m.
Tell your doctor if you:
- Are allergic to any substance that contains iodine.
- Have asthma or have ever had a serious allergic reaction (anaphylaxis) from any substance, such as the venom from a bee sting.
- Are allergic to any medicines and whether you are taking any erection-enhancing medicines, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra). This test may require the use of nitrate medicine, such as nitroglycerin, that can cause severely low blood pressure if you have taken an erection-enhancing medicine within the previous 48 hours.
- Have any bleeding problems or take blood-thinning medicine (anticoagulant).
- Are or might be pregnant.
- Have kidney disease. The contrast material used during cardiac catheterization can cause kidney damage in people who have poor kidney function. If you have a history of kidney problems, blood tests (creatinine, blood urea nitrogen) may be done before the test to confirm that your kidneys are functioning properly.
- Have diabetes, especially if you take metformin (Glucophage). Your doctor may instruct you to stop the medicine 48 hours before the test.
Do not eat or drink (except for a small amount of water) for six to 12 hours before the test.
Be sure to empty your bladder completely just before the test.
How long does it take?
The procedure takes between 10 to 15 minutes; however, you will need to stay three to four hours after the procedure to rest and recover.
What to expect after a cath test
Minor bruising and a small lump or knot (smaller than a quarter) at the insertion site are normal and expected after a catheterization. This should go away in two to six weeks. Check the site occasionally for oozing, swelling or enlarging lump/knot. This is an indication that you are bleeding internally or externally. If this occurs, your physician should be called immediately and you should lay down flat and have someone apply firm pressure on and above the puncture site for 15 to 20 minutes.
Should swelling and bleeding continue as you press, you need to reposition the point of pressure slightly and follow any further instructions your physician has given you. If bleeding persists, you should call 911.
The soreness and bruising should disappear within two weeks. It is normal for the site to feel tender for about a week.
- Avoid strenuous activity for at least 48 hours.
- Drink plenty of liquids for several hours after the test to prevent dehydration and help flush the dye out of your body.
Care of your incision:
- After the procedure, wait 24 hours before showering. Remove the hospital dressing while showering.
- Gently clean the site using warm, soapy water. Dry thoroughly.
- Cover the site with a bandage or dressing that covers the entire site
- Keep the dressing clean and dry to prevent infection. If the bandage becomes wet, remove that one and place a new one.
- Do not put ointments, oils or lotions on the catheterization site.
- Do not take baths in a tub (or swim in a pool) for the first seven days.
- Inspect the site daily.
- If a closure device was used, please follow the instructions provided.
Call 911 or go to the emergency department of the nearest hospital if you develop:
- Chest pain
- Increased shortness of breath
- Dizziness, trouble speaking or swallowing
- Loss of feeling in the leg or foot on the side of the catheterization
- Increased swelling in the groin or leg
- Unusual groin pain or pain in your right/left leg
- A redness, swelling, warmth or discharge at the catheter insertion site
- A fever
- Bleeding that does not stop after 10 minutes of applying firm pressure directly to the incision