Intravascular ultrasound (IVUS), or intravascular echocardiography, is performed in combination with cardiac catheterization. IVUS uses sound waves to produce images from inside the coronary arteries, making it possible to evaluate the type and amount of disease present, how it is distributed, and the need for further treatment, prevention, or risk factor management.
How It Works
The high-frequency (ultrasound) sound waves travel through a catheter that is threaded through a peripheral artery up into the heart. A miniature probe (transducer) on the tip of the catheter is threaded into the coronary arteries. The sound waves bounce off of 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. The pictures come from inside the heart rather than through the chest wall, producing detailed images of the interior walls of the arteries. IVUS is rarely done alone or as a strictly diagnostic procedure. It is usually done in conjunction with a percutaneous coronary intervention, such as angioplasty.
What To Expect
Patients receive protocols from their doctors regarding eating and drinking prior to the test and regarding taking medication before the test, including insulin. As with most hospital procedures, patients should bring their list of medicines along. Patients may have blood tests, an electrocardiogram, and a chest x-ray taken before this procedure.
In the catheterization laboratory (also called the cath lab), the patient sees television monitors, heart monitors, and blood pressure machines and lies on an examination table. Electrodes, leads, and various monitors are placed on the patient. The catheter insertion area on the patient’s leg is prepped. An intravenous line, or IV, is inserted in the patient’s arm into which a mild sedative is administered throughout the test.
The doctor places the catheter into the leg artery and gently threads it up and into the heart. The ultrasound transducer on the end of the catheter is used to take the pictures from inside the heart. The catheter is rotated or moved to take pictures from different angles.
After the test, the patient is moved to a recovery room and may feel drowsy until the sedative subsides. The patient will follow the doctor’s rest and recovery protocol. Those who are able to go home afterwards should have a companion to drive them. The IVUS procedure takes about 60 minutes.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Diag/diivus.cfm
The Cleveland Clinic www.clevelandclinic.org/heartcenter/pub/guide/tests/invasive/ivus.htm