Intravascular Ultrasound (IVUS) is a combination of echocardiography and a procedure called cardiac catheterization. Intravascular Ultrasound uses sound waves to produce an image of the coronary arteries and to see their condition. The sound waves are sent through a tube called a catheter, which is threaded through an artery and into your heart. This test lets doctors look inside your blood vessels.
Intravascular Ultrasound is rarely done alone or as a strictly diagnostic procedure. It is usually done at the same time that a transcatheter intervention like angioplasty is being performed.
How it works?
Intravascular Ultrasound uses high–frequency sound waves (also called ultrasound) that can provide a moving picture of your heart. The pictures come from inside the heart rather than through the chest wall. The sound waves are sent with a device called a transducer. The transducer is attached to the end of a catheter, which is threaded through an artery and into your heart. The sound waves bounce off the walls of the artery and return to the transducer as echoes. The echoes are converted into images on a television monitor to produce a picture of your coronary arteries and other vessels in your body.
What to expect?
Do not eat or drink anything after midnight the night before your test. Talk to your doctor about any medicines that you are taking, because he or she may want you to stop taking them before the test. Also, it may be helpful if you bring your medicines with you to the procedure, so that the doctors and technicians know exactly what you are taking and how much. You will most likely have blood tests, an electrocardiogram, and a chest X–ray taken before the procedure.
Once you are in the catheterization laboratory, you will see television monitors, heart monitors, and blood pressure machines. You will lie on an examination table, which is usually near an X–ray camera. Electrodes will be placed on your chest. These electrodes have wires called leads, which hook up to an electrocardiogram machine. This machine will monitor your heart rhythm during the test.
To prevent infection, you will be shaved and cleansed around the area of your groin or arm where the catheter will be inserted. A needle with a tube connected to it will be put in your arm. This is called an intravenous line or IV. You will get a mild sedative through the IV to relax you throughout the test. You will be given an anesthetic medicine with a needle to numb the area around where the catheter will be inserted. You may feel mild discomfort. Then, a small incision will be made in the skin. Once doctors see the vein or artery into which the catheter will go, a special needle is used to poke into it. Doctors then put the catheter into the artery or vein in your groin or arm. You should not feel pain during this part of the test.
The catheter is gently threaded through the artery and into your heart. On the end of the catheter is the transducer, which takes pictures of your heart. Doctors can move the catheter to take pictures of the inside of your heart at different angles. After the doctors have enough pictures of your heart, the catheter and IV line will be removed. You will also be disconnected from the electrocardiogram machine. Firm pressure will be applied to the site where the catheter was inserted to stop any bleeding. You will also be bandaged.
You will be moved to another room where you will need to rest for 5 or 6 hours. You may feel a little sleepy until the sedative has worn off. You will be told to lie still. If the catheter was inserted in your groin, try not to bend your knee. If the catheter was inserted in your arm, try not to bend your elbow. Nurses will watch you to see that your heart rate and blood pressure are normal. After this time of rest, you can go home.