The test can be performed at the bedside in an intensive care unit or in special procedure areas such as a cardiac catheterization laboratory. A mild sedative is sometimes given before the procedure.

A trained physician inserts the catheter into the right side of the heart through a large vein. Typically, a vein in the right side of the neck is used. However, the left side of the neck, either side of the groin, and other sites can be used.

Before inserting the catheter, the area that is used will be cleaned with sterile soap, injected with local anesthesia and an intravenous (IV) catheter will be placed using a needle. The catheter is inserted through the IV and then into the vein.

The catheter enters the right atrium (upper chamber) of the heart, flows through the tricuspid valve into the right ventricle (lower chamber), through the pulmonary valve, and into the pulmonary artery. Measurements of the pressures in the pulmonary artery can be used to indirectly measure the function of the left ventricle.

The position of the catheter within the heart is confirmed by a chest x-ray or by fluoroscopy during the procedure and by monitoring devices that also read the pressures within the heart. During the procedure, the heart's rhythm is monitored continuously by electrocardiogram (ECG).

You should not consume any food or fluid for 8 hours before the procedure. You may need to be admitted to the hospital the night before the procedure. Otherwise, you will be admitted as an outpatient or inpatient the morning of the procedure, if the procedure is elective. In critically ill patients, the test may be carried out in the intensive care unit.

You will wear a hospital gown and will provide a witnessed, signed consent for the procedure. A health care provider will explain the procedure and its risks. A mild sedative is usually given 30 minutes before the procedure.

In infants and children:
The preparation you can provide for this test depends on your child's age, previous experience, and level of trust. For general information regarding how you can prepare your child, see the following topics:

• Infant test/procedure preparation (birth to 1 year)
• Toddler test/procedure preparation (1 to 3 years)
• Preschooler test/procedure preparation (3 to 6 years)
• Schoolage test/procedure preparation (6 to 12 years)
• Adolescent test/procedure preparation (12 to 18 years)

Although you will receive sedation to relax you prior to the procedure, you will be awake and able to follow instructions during the test. You will remain on a stretcher or bed for the duration of the test. An insertion is made into a vein for threading the catheter into the heart. Local anesthesia is given to insert the catheter, and the only sensation is one of pressure at the site.

You may experience some discomfort due to lying still for a prolonged period of time. The procedure may last up to 1 hour, and in critically ill patients, the catheter may remain in place for several days for monitoring.

The procedure is performed for the following reasons:

• To evaluate circulatory volume under the following conditions:
  • Heart failure
  • Shock
  • Acute valvular regurgitation
  • Congenital heart disease
  • Burns
  • Kidney disease
• To monitor for complications of heart attack
• To monitor effects of certain heart medications

Swan-Ganz catheterization can be used to detect abnormal blood flow between two usually unconnected areas (shunt). Conditions that can also be diagnosed or evaluated with Swan-Ganz catheterization include pulmonary hypertension, cardiac tamponade, and restrictive cardiomyopathy.

• pulmonary artery systolic pressure is 15 to 30 mmHg
• pulmonary artery mean pressure is 9 to 17 mmHg
• pulmonary diastolic pressure is 0 to 8 mmHg
• pulmonary capillary wedge pressure is 5 to 15 mmHg
• cardiac index is 2.4 to 4.2 L/min/M2
• right atrial pressure is 0 to 8 mmHg

mmHg = millimeters of mercury
L/min/M2 = liters per minute per square meter (of body surface area).

The main risks of the procedure are bruising at the access site, trauma to the vein, and lung puncture if the neck or chest veins are used. Very rarely patients may suffer cardiac arrhythmias, cardiac tamponade, low blood pressure, infection, or embolism caused by blood clots at the tip of the catheter.