Left heart catheterization is the passage of a catheter (a thin flexible tube) into the left side of the heart. The procedure may be performed to obtain diagnostic information about the left side of the heart or to treat certain types of heart conditions.

The procedure can also be used to determine pressure and blood flow in the heart's chambers, to collect blood samples from the heart, and to examine the arteries of the heart by a type of x-ray called fluoroscopy.

You will be given a mild sedative prior to the test. An intravenous (IV) catheter will be inserted in your arm so that medication can be given during the procedure. A radiologist or cardiologist will insert this catheter through a small incision in the femoral or brachial artery after cleansing the site and numbing it with a local anesthetic.

The catheter will then be threaded into your heart through the aorta and aortic valve and then into the left ventricle. Moving x-ray images called fluoroscopy will guide the procedure. When the catheter is in place, a contrast material ("dye") will be injected for the x-ray. This will allow the structures and vessels within the heart to be seen.

You will not be allowed to eat or drink for 6 - 8 hours before the test.

The procedure will take place in the hospital. You may be admitted the night before the test, but it is common to come to the hospital the morning of the procedure.

You health care provider will explain the procedure and its risks. You must sign a consent form in order for the procedure to be performed.

You will be given a mild sedative 1/2 hour before the procedure. The procedure itself may last from 1 to several hours.

The procedure will take place in a radiology department or cardiac diagnostic laboratory. You will be given sedation to relax prior to the procedure, but you will be awake and able to follow instructions during the test.

You will be given local anesthesia before the catheter is inserted, and so the only sensation you will feel is pressure at the site. You may experience some discomfort due to lying still for a prolonged period of time.

The procedure is performed to evaluate cardiac valve disease, heart function and blood supply, congenital heart anomalies, and to determine the need for heart surgery. The procedure may also be done to repair certain types of heart defects, open a stenotic heart valve, or open obstructed arteries or bypass grafts.

Normal heart size, normal heart motion and thickness, normal heart blood supply (if coronary angiography is also performed), normal heart pressures are found.

Cardiac defects or disease may be present. These could include

• Coronary artery disease
• Valvular heart disease (see below)
• Ventricular aneurysms
• Enlargement of the heart.

Additional conditions for which the test may be performed include:

• Aortic insufficiency
• Aortic stenosis
• Acute mitral regurgitation
• Mitral stenosis

Risks of the procedure are trauma to the artery, cardiac arrhythmias, cardiac tamponade, low blood pressure, infection, embolism from blood clots at the tip of the catheter, reaction to the contrast material, stroke, and heart attack.