- coronary angiography
- heart catheterization
- coronary angiogram
- cardiac angiography
Cardiac catheterization is a test used to diagnose abnormalities of the coronary blood vessels. These vessels supply blood to your heart muscle. The test can also be used to observe your heart chambers and heart valves.
Who is a candidate for the test?
This test may be advised for people who have or are suspected to have one of the following conditions:
- abnormal enlargement of the heart
- angina, whether stable angina or unstable angina, which is the chest pain that you get when too little oxygen reaches your heart for a short period
- coronary artery disease, which is a blockage in the arteries that supply blood to your heart, and is often the cause of angina and heart attacks
- heart attack, which occurs when the coronary is completely occluded and the heart is deprived of enough oxygen
- heart defects present at birth, also called congenital heart disease
- irregular heartbeats, which are also called arrhythmias
- evaluation of valvular heart disease
- evaluation of pericardial disease
How is the test performed?
Cardiac catheterization is done in a special room with cameras, TV screens, and X-ray devices. Usually, the doctor who performs the test is a heart specialist, also called a cardiologist. Sometimes, an X-ray specialist, called a radiologist, may perform the test.
During the procedure, the doctor and his or her assistants operate the equipment in the suite. A nurse checks your vital signs, such as heart rate and blood pressure, throughout the exam. During the test, you lie on a flat platform.
The doctor selects an artery in which to insert the catheter. The femoral artery (for left heart catheterization) or femoral vein (for right heart catheterization) in the right groin is used most often. The skin in the groin area is numbed with local anesthesia. A small needle is then inserted through your skin and into your blood vessel.
Next, the doctor inserts a catheter into your blood vessel through the small puncture made with the needle. After being placed in the blood vessel, the catheter can be pushed up toward your heart.
In the case of left heart catheterization, the catheter moves up the aorta. This is the largest artery in your body. It connects directly to your heart and can be used to get into your heart chambers. Your coronary arteries, which supply blood and oxygen to your heart, also stem from the aorta.
An X-ray machine is used to help guide the catheter into proper position. Dye is used to light up the structures of your heart and its arteries on the X-ray machine. The dye is injected into the catheter and enters your heart and heart arteries. This allows these structures to be clearly seen, as the dye used is easily seen when X-ray pictures are taken.
Pictures are taken with an x-ray machine as the dye travels through your heart and heart arteries. The doctor usually takes several pictures of your heart filled with dye from different angles and positions. More than one injection of the dye is often needed.
The images can be projected onto a TV or video screen so that the doctor can view your heart and its arteries during the test. The standard test will typically take less than an hour. However, in more complex cases, the exam may last for several hours.
The doctor may sometimes see an abnormality during the test that can be corrected during the exam. For example, a procedure called angioplasty is sometimes used to open up clogged arteries. This involves inserting a balloon catheter or other device through the catheter to open the area of blockage.
What is involved in preparation for the test?
Special preparation is needed before the test. A brief physical exam is done to evaluate pulses in your groin and legs. If you have a weak pulse in your groin, your doctor may use a different artery to insert the catheter. Your doctor will also review your medical and surgical history. He or she may ask questions such as the following.
- Do you have a bleeding tendency or any blood disorders?
- Do you have any kidney disease or other kidney problems?
- Have you had a prior allergic reaction to contrast agent or dye?
- Do you take blood thinning medicines such as aspirin or warfarin?
Before the test, your blood is checked for kidney function and for signs of a bleeding tendency. A woman of childbearing age will be screened for pregnancy. This is usually done with a urine or blood pregnancy test. Radiation from the test could harm an unborn child.
You cannot eat or drink anything for six to eight hours before the test. Dentures, eyeglasses, and jewelry, such as necklace or earrings, should be removed before the exam.
The risks, benefits, and complications of the test are usually explained to you on the day of the procedure. Some possible complications you may have from the test are as follows:
- allergic reactions to the contrast agent used
- renal failure from the contrast dye used for the test
- infection at the puncture site
- bleeding in the groin that could possibly require the need for a blood transfusion or surgery to repair the damaged artery in the leg
- heart attack, which occurs in less than 1% of cases
- irregular heartbeats called arrhythmias
- stroke, which occurs in less than 1% of cases
- having to shock the heart when the dye is injected into the coronary artery
If procedures are done during the exam, such as angioplasty, additional risks are involved. These will be discussed before the test by your doctor.
This test may be done on an outpatient basis. This means that you can go home after the test. However, sometimes you might have to stay in the hospital for a day or more after the test. This test is also used for people in the hospital who have serious or life-threatening heart conditions.
What do the test results mean?
The doctor who performs the test is usually the one who will review the results with you. This involves looking at the pictures taken during the exam to check for any abnormalities. The doctor uses the results of this test to help plan your treatment and figure out the next course of action.
Diagnostic Imaging, Reference and Review, by Ralph Weissleder (1998)
Handbook of Interventional Radiology and Angiography, Second Edition, by Myron Wojtowycz (1995)