Explore This Procedure

Overview: Cardiac Catheterization

Cardiac catheterization is performed in an area of the hospital called the catheterization lab. The rooms in the catheterization lab have specialized equipment that allow cardiologists to see instant moving images of the heart. During the procedure, a thin plastic tube (a catheter) is guided through a main artery in the leg or arm and up to the heart. Once the catheter is in the heart, the physician injects a dye, which helps track blood flow on the image. If the physician identifies arteries that are narrow or blocked, there are several cardiac catheterization techniques, called interventional procedures, which can often be used to improve blood flow.

Tests Needed Prior to Cardiac Catheterization

Once your physician determines that you need a cardiac catheterization, various tests will help properly assess your condition prior to the procedure. You may have already received tests before your referral; however, Mass General Hospital staff may request additional testing.

The following are necessary prior to scheduling a catheterization:

  • A history and physical examination by a cardiologist
  • An electrocardiogram (EKG)
  • Blood tests

Other tests may be requested:

  • Exercise tolerance test (treadmill test)
  • Echocardiogram (an ultrasound study)
  • Gated blood pool scan (nuclear scanning of your heart)
  • Chest X-ray 

Preparing for Your Heart Procedure

If you are scheduled for admission on the day of your procedure, follow these specific preparation instructions:

  • Do not eat food or drink (except a few sips of water with medication) after midnight
  • Continue to take medications on your prescribed schedule. Medications such as Coumadin, diuretics, insulin and oral diabetic medication will require individual review by your physician
  • Discuss medications, allergies and any other issues with your doctor prior to the procedure
  • The afternoon prior to your procedure, a nurse from the catheterization lab will contact you to provide additional instructions and let you know when to arrive at the lab. Please use this opportunity to address any questions or concerns about your procedure
  • For your same-day admission, please arrive in the catheterization lab at your designated time. A family member or friend may accompany you. For your convenience, there is a comfortable reception area with cafeteria services and public phones nearby
  • It is not be necessary to bring anything with you except personal toiletries and medications you may need. Please do not bring any valuables or jewelry. Wear comfortable clothing and walking shoes. Please bring a book or other diversion to help pass the time in case of delays

When you arrive at the Knight Center for Interventional Cardiovascular Therapy, located on the 9th floor of the Blake building, a receptionist will greet you and notify the team that you have arrived. As your procedure time nears, a nurse will ask you to change into hospital attire. You are then brought into the pre-procedure holding area

Preparing for Your Heart Procedure in the Hospital

For patients in the hospital, a catheterization lab physician will visit you the evening before your procedure. At this time, you have an opportunity to discuss the procedure, ask any questions and sign a consent form.

Adjustments may be made to your prescribed medication routine, and an IV will be inserted. You will not be able to eat or drink (except water with medications) after midnight. Your nurse will ensure that you are properly prepared.

In the Pre-Procedure Holding Area

During your wait in the pre-procedure area, a nurse will review your medical record and discuss any questions or concerns you may have. The nurse will check your vital signs, assess the circulation to your legs and insert an IV.

You will meet one of the physicians scheduled to perform your catheterization. The physician will explain the procedure in greater detail and outline the potential risks.

If you have not already done so, you will sign a consent form indicating your willingness to have a catheterization performed. The nurse will administer pre-catheterization medications, consisting of a mild sedative to relax you.

During the Cardiac Catheterization Procedure

Once you are in the procedure room, you will be moved to a flat, moveable examination table. Cameras are located above, below and to the sides of the table. There will be many monitors visible around the room. The nurse and technologist, who will be with you and assist the physicians during your catheterization, will begin the pre-catheterization preparation.

Electrodes will be attached to your chest to monitor your heart rate and rhythm. The selected area for insertion of the catheters will be shaved and washed with an antiseptic to ensure that the catheter entry site is clean and sterile. You will be draped with a sterile sheet to provide the most sterile environment for catheter insertion. The most common entry site is the upper area of your thigh, but occasionally the middle of the arm is preferable.


You will be mildly sedated throughout the procedure. It will be necessary for us to communicate with you, and we need to know if you are experiencing any discomfort. If you feel anxious, you may request additional sedation.

A local anesthetic is injected to numb the skin at the insertion point, and you may experience a brief burning or stinging sensation. An introducer sheath is placed in the artery and in the vein. The sheath acts as the entry tube for the various catheters required during the procedure. Some patients feel pressure or mild discomfort when the sheath is being inserted.

Physicians need to obtain a variety of information relevant to each patient’s clinical situation. Therefore, the sequence and type of measurements collected may vary from patient to patient.

Recording Pressures and Pictures

From this point on, the lights will be dimmed periodically for viewing purposes. Typically, pressures are recorded in the various chambers and vessels of your heart. It is important not to talk as pressures are recorded because measures should reflect a normal resting pressure. You should not experience any discomfort; however, be sure to tell the staff if you feel uncomfortable.

Physicians will take pictures of your arteries and the main pumping chamber. To accomplish this, the doctor will manually inject dye through a catheter into the artery that supplies blood to the heart muscle. You may feel pressure in your in chest when the dye is injected, and it is important for you to tell us if this happens. Cameras will move around your chest, and the table will move so the dye can be followed as it travels through the vessels. Many pictures will be taken from different angles to thoroughly understand the blood flow through your arteries.

A catheter will be placed into the left pumping chamber of your heart. This time a machine will inject dye. Moving pictures will evaluate the left ventricle and main pumping chamber functions. This causes a momentary hot and flushed feeling throughout your body. These feelings should pass quickly.

A Discussion with Your Physician

After all measures are taken, your physician will discuss the findings with you and present options for further treatment. Your options may include:

  • No treatment
  • A change in medications
  • Another type of catheterization called an interventional procedure
  • Cardiac surgery

If an intervention is recommended, it is often done while you are still in the procedure room. The type of interventional procedures performed is based on severity, location and degree of blockage.

On your scheduled procedure day, the catheterization lab will put you on call, meaning that you are ready to go to the lab. Pre-procedure medications will be administered, and you will be brought from your room directly to the pre-procedure holding area in the catheterization lab.

After Your Cardiac Catheterization Procedure

If no other tests or treatment are required, the cardiac staff will prepare to bring you to the post-procedure area for recovery. A nurse may administer additional medication, drapes will be removed and monitoring equipment will be disconnected. You will need to keep your leg straight, particularly as you are moving from the table to a stretcher.

In the recovery area, your sheaths will be taken out. This may cause pressure or discomfort at the entry site. Immediately after the sheath is removed, the staff will apply firm and direct pressure by hand or with a clamp device. Pressure is maintained for approximately 20 to 30 minutes to help stop bleeding and to allow the puncture site to heal. A nurse will continue to monitor your blood pressure, heart rate, the entry site, and your circulation. Once the staff is sure that the entry site is stable, an adhesive strip will be applied.

The four to six hours following your catheterization are very important, and we ask that you carefully follow these instructions about your care. A nurse will frequently check your vital signs and make sure your entry site is healing properly.

Please tell the staff immediately if you experience the following:

  • Chest, neck, jaw, or arm pain or any pain similar to your heart pain
  • Shortness of breath
  • Weakness or dizziness
  • Pain at the entry site
  • Numbness, tingling or any discomfort below the entry site
  • A warm or wet sensation around the entry site area
  • Any other discomfort

Bed rest is essential to ensure that the puncture site heals. You will need to lie flat, and you may only raise your head slightly (30 degrees). You should not turn from side to side. You may bend your foot or wiggle your toes, but do not bend your knee. If you have to cough or sneeze, apply firm, direct pressure over the adhesive strip on your groin.

You will need to drink extra fluid to help your kidneys eliminate the X-ray dye. Since you will not be able to get out of bed, a nurse will assist you in the use of a urinal or bedpan. Back discomfort may occur. Please let us know if you are concerned about your back. We will try to alleviate your discomfort.

Following your resting period, a nurse will help you get out of bed. This should be done slowly and carefully. We recommend that your initial activity be limited to short trips (i.e. possibly to a nearby bathroom). The following day you may resume light activity. If you are going home the evening of your procedure, you will be given additional written instructions before you are discharged.

Please be prepared for the following:

  • Plan to stay in the hospital for six to eight hours after your procedure is finished
  • Have an escort or family member pick you up and drive you home from the hospital
  • You cannot spend the night following your catheterization home alone. Please plan to have a companion with you
  • Limit your activity to your trip home
  • Resume light activity (around home) the next day

Before you leave, discuss these important points with your physician:

  • The findings of your catheterization
  • Your activity level
  • Your medications
  • Who to contact in the case of an emergency
  • Any other details specific to your care

Patient Resources

Mass General is dedicated to ensuring that people understand their health care choices and have the necessary information to make decisions affecting their health and wellbeing. The related support and wellness information listed below can play a role in treatment options.

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