Cardiac Catheterization

Medically Reviewed by James Beckerman, MD, FACC on February 14, 2024
6 min read

Cardiac catheterization (also called cardiac cath, heart cath, or coronary angiogram) is a procedure that allows your doctor to see how well your blood vessels supply your heart. During the test, they put a long, narrow tube called a catheter into a blood vessel in your arm or leg and guide it to your heart with the aid of a special X-ray machine. Doctors use contrast dye that they inject into your blood vessel through the catheter to create X-ray videos of your valves, coronary arteries, and heart chambers.

Your doctor uses cardiac cath to:

Common uses of cardiac catheterization

Your doctor can use cardiac cath to both find and fix problems. Procedures that might be done during your cardiac cath include:

  • Angioplasty. Your doctor inserts a catheter with a tiny balloon at the tip. When this balloon is inflated, it pushes plaque out and widens your artery.
  • Biopsy. Your doctor takes a small sample of tissue from your heart.
  • Repair of heart defects. Your doctor closes a hole in your heart or stops a leak in a valve.
  • Stent placement. Your doctor places a tiny mesh tube called a stent into your artery to help keep it open.
  • Valve replacement. Your doctor may do a minimally invasive procedure called Transcatheter Aortic Valve Replacement (TAVR) to replace a faulty aortic valve.

A cardiac cath is generally safe. But as with any procedure that involves going into your body, there are risks. Your doctor will discuss the risks with you and be careful to lessen the chances of having them.

Risks can include:

What happens before cardiac catheterization?

This procedure is usually done at a hospital. Most people will also need blood tests and an EKG. Some other things to keep in mind:

  • Your doctor or nurse will tell you what you can and can’t eat or drink before the procedure.
  • Tell your doctor all the medications you’re taking, including herbal products and dietary supplements.
  • Ask your doctor what drugs you should take on the day of your cardiac cath. You may need to stop taking some of them, such as Coumadin (a blood thinner), for a few days before the procedure.
  • If you have diabetes, ask your doctor how to adjust your diabetes drugs on the day of your test.
  • Tell your doctor and nurses if you’re allergic to anything, especially iodine, shellfish, X-ray dye, latex, rubber products (such as rubber gloves or balloons), or penicillin-type medications.
  • You might not be able to go home on the day of your procedure. Bring personal items with you (such as a robe, slippers, and a toothbrush) to make your stay more comfortable. Have someone else take you home.

How long does a cardiac catheterization last?

A cardiac cath procedure usually takes about 30 minutes (and longer if you have an intervention), but the preparation and recovery time add several hours. Plan on being at the hospital all day.

What happens during a cardiac catheterization?

You’ll put on a hospital gown. A nurse will put an intravenous (IV) needle in your arm in order to give you medications and fluids.

The cardiac cath room looks like an operating room. You’ll lie on a special table. A large camera and several TV monitors will be above you. You can watch the pictures from your cardiac cath on the monitors.

The nurse will clean and possibly shave the site where they’ll insert the catheter (in your arm or groin). Sterile cloths will cover the site and help prevent infection. Keep your arms and hands at your sides so you don’t move the drapes.

The nurse will put electrodes (small, flat, sticky patches) on your chest. The electrodes are attached to an EKG machine that charts your heart's electrical activity.

Your doctor will give you a mild drug to help you relax, but you’ll be awake during the procedure. Your doctor will use a medication called a local anesthetic to numb the area where the catheter goes in. This could be at your groin (they’ll call this the femoral approach) or on your wrist (the radial approach).

Your doctor will make a small cut over the blood vessel. They’ll insert a device called an introducer sheath and thread the catheter through it into the arteries of your heart. You might feel some pressure but shouldn’t feel pain. If you feel any pain, tell your health care providers.

When the catheter is in place, they’ll dim the lights and insert a small amount of dye (also called contrast material) through the catheters into your arteries and heart chambers. The contrast material outlines your vessels, valves, and chambers.

When the doctor injects the dye into your heart, you may feel hot or flushed. This is normal and will go away in a few seconds. Tell the doctor or nurses if you feel itching or tightness in your throat, nausea, chest discomfort, or any other symptoms.

The X-ray camera will take photographs of your arteries and heart chambers. Your doctor may ask you to take a deep breath, hold your breath, or cough during the procedure. You’ll need to hold your breath while they’re taking the X-rays. When all the photos are done, the team will remove the catheter and turn on the lights.

What happens after a cardiac catheterization?

If the catheter was put in your wrist, your doctor will remove it and the sheath. They’ll close the cut and bandage it. You’ll be able to walk around.

The doctor will watch you for a few hours to make sure you’re feeling OK. Tell your nurse if you think you’re bleeding or feel any numbness or tingling in your fingers. You might get medication to help with discomfort in your arm. You’ll also get instructions about how to care for your arm after you go home.

If the catheter went into your groin, your doctor will remove the device and close the cut with stitches, a collagen seal, or pressure. A collagen seal is a protein material that works with your body's natural healing processes to form a clot in your artery. In some situations, your doctor might stitch the introducer sheath into place and take it out after the bleeding stops.

To help prevent infection, your wound will be covered with a sterile dressing. You’ll need to lie flat and keep your leg straight for 2 to 6 hours to prevent bleeding. To avoid straining your abdomen and groin, you’ll need to keep your head low (no more than two pillows high). You won’t be able to sit up or stand during this time. The nurse will check your bandage regularly, but tell them if you think you’re bleeding (have a wet, warm sensation) or if your toes tingle or feel numb. You might get medication to help with discomfort after the anesthetic wears off. Your nurse will help you out of bed when it’s OK for you to get up.

Your doctor's orders will let you know when you can get out of bed to go to the bathroom. The nurse will help you sit up and dangle your legs on the side of the bed.

Drink plenty of liquids to clear the dye out of your body.

You may feel the need to pee more often than usual. This is normal. If you didn’t get a urinary catheter during the procedure, you’ll need to use a bedpan or urinal until you’re able to get out of bed.

Your doctor will tell you if you can go home or will need to stay overnight.

Before you go home, your doctor will discuss treatment, including medications, dietary changes, exercise, and future procedures. They’ll also talk about how you should care for the wound site, activity, and follow-up care.

Your doctor will tell you what they found during the procedure and whether they needed to do any other procedures, like an angioplasty or stent.

Once you get home, follow all of your doctor’s instructions about your activity level and what medications to take. You might have a bruise at the wound site. Call your doctor if you have any other problems.