Cardiac catheterization may be performed as either an inpatient or outpatient procedure (sometimes referred to as an ambulatory cardiac catheterization). However, the American Heart Association and the American College of Cardiology stress that this test should be done in a hospital’s catheterization laboratory to be sure that appropriate resources are available should problems arise.

On the day of the procedure, the patient is taken to a cool and sterile catheterization laboratory that, to a patient, may resemble an operating room with its many monitoring devices, video display equipment and x-ray cameras. A nurse or physician will explain what is going to happen and the patient is encouraged to ask any questions that he or she may have.

Once the patient is made comfortable, the physician inserts an intravenous (I.V.) line into the patient’s wrist or arm. The I.V. allows the physician to give the patient a sedative and other necessary medications during the procedure. Small devices will be taped to the patient’s body, which allow the physician to monitor heart rate and rhythm.

The physician usually uses the groin/upper thigh area (the femoral artery) as the place where the catheter will enter the body on its way to the heart, but some physicians may choose to use the elbow or wrist. Whichever area is chosen will be cleaned, shaved, swabbed with germ-killing solution and numbed (with a local anesthetic). The catheter is then fed through the artery in that area (e.g., the femoral artery in the groin/upper thigh) and up into the heart. There may be some minor discomfort during this period. However, patients should let someone know if they are feeling any pain.

The physician will position the catheter in the left ventricle of the heart (although some physicians may choose to begin with the coronary arteries). When the catheter is correctly positioned in the left ventricle (and, if measuring the right heart pressure, another catheter is placed in the pulmonary artery), blood pressure measurements will be taken. Blood samples may also be taken. While the catheter is still in place in the left ventricle, a left ventriculogram may be performed to gain a clear picture of the left ventricle’s structure and functioning. To perform the ventriculogram, a special dye (contrast medium) is injected through the catheter and into the left ventricle. The injection of the dye may cause brief, normal experiences such as the following:

Following the left ventriculogram, a coronary angiogram is usually performed. The physician positions a different catheter in the coronary arteries and completes the coronary angiogram.

In some cases, an aortogram is also necessary. This part of the catheterization gives a clear image of the aorta (the main artery carrying oxygen-rich blood from the heart to the rest of the body). Following these procedures, the cardiac catheterization is complete. The entire test may take between 20 minutes and an hour depending upon factors such as physician experience.