The passage of a catheter (a thin flexible tube) into the left side of the heart to obtain diagnostic information about the left side of the heart or to provide therapeutic interventions in certain types of heart conditions.

The test can determine pressure and blood flow in the heart's chambers, collect blood samples from the heart, and examine the arteries of the heart by X-ray (fluoroscopy).

You are given a mild sedative prior to the test. An intravenous catheter is started in your arm to allow for the administration of medication during the procedure. A radiologist or cardiologist inserts the catheter through a small incision in the femoral or brachial artery after cleansing the site and numbing the site with a local anesthetic.

The catheter is then carefully threaded into your heart through the aorta and aortic valve and then into the left ventricle using X-ray images called fluoroscopy to guide the insertion. When the catheter is in place, dye is injected to visualize the structures and vessels within the heart.

Adults:
Food and fluid is restricted for 6 to 8 hours before the test. The procedure takes place in the hospital. Sometimes, admission the night before the test is required. Otherwise, admission as an outpatient or inpatient the morning of the procedure is required. A health care provider must explain the procedure and its risks. You must sign a consent form for the procedure.

You are given a mild sedative 1/2 hour before the procedure. The procedure may last from 1 to several hours. You will wear hospital clothing.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

• infant test or procedure preparation (birth to 1 year)
• toddler test or procedure preparation (1 to 3 years)
• preschooler test or procedure preparation (3 to 6 years)
• schoolage test or procedure preparation (6 to 12 years)
• adolescent test or procedure preparation (12 to 18 years)

The procedure takes place in a radiology department or cardiac diagnostic laboratory. You are given sedation to relax prior to the procedure, but you are awake and able to follow instructions during the test. You will remain on a stretcher for the duration of the test.

An insertion is made into an artery for threading the catheter into the left side of your heart. You are given local anesthesia to insert the catheter, and the only sensation is one of pressure at the site. Discomfort may arise from having to lie still for prolonged periods of time.

Cardiac defects or disease may be present. These could include coronary artery disease, valvular heart disease (see below) , ventricular aneurysms, or enlargement of the heart.

Additional conditions under which the test may be performed:

• aortic insufficiency
• aortic stenosis
• mitral regurgitation; acute
• mitral stenosis