What is cardiac catheterization?
In cardiac catheterization (often called cardiac cath), your doctor puts a very small, flexible, hollow tube (called a catheter) into a blood vessel in the groin, arm, or neck. Then he or she threads it through the blood vessel into the aorta and into the heart. Once the catheter is in place, several tests may be done. Your doctor can place the tip of the catheter into various parts of the heart to measure the pressures within the heart chambers or take blood samples to measure oxygen levels.
Your doctor can guide the catheter into the coronary arteries and inject contrast dye to check blood flow through them. (The coronary arteries are the vessels that carry blood to the heart muscle.) This is called coronary angiography.
These are some of the other procedures that may be done during or after a cardiac cath:
- Angioplasty. In this procedure, your doctor can inflate a tiny balloon at the tip of the catheter. This presses any plaque buildup against the artery wall and improves blood flow through the artery.
- Stent placement. In this procedure, your doctor expands a tiny metal mesh coil or tube at the end of the catheter inside an artery to keep it open.
- Fractional flow reserve. This is a pressure management technique that’s used in catheterization to see how much blockage is in an artery
- Intravascular ultrasound (IVUS). This test uses a computer and a transducer to send out ultrasonic sound waves to create images of the blood vessels. By using IVUS, the doctor can see and measure the inside of the blood vessels.
- A small sample of heart tissue (called a biopsy). Your doctor may take out a small tissue sample and examine it under the microscope for abnormalities.
During the test, you will be awake, but a small amount of sedating medicine will be given before starting to help you be comfortable during the procedure.
Why might I need cardiac catheterization?
Your doctor may use cardiac cath to help diagnosis these heart conditions:
- Atherosclerosis. This is a gradual clogging of the arteries by fatty materials and other substances in the blood stream.
- Cardiomyopathy. This is an enlargement of the heart due to thickening or weakening of the heart muscle
- Congenital heart disease. Defects in one or more heart structures that occur during fetal development, such as a ventricular septal defect (hole in the wall between the two lower chambers of the heart) are called congenital heart defects. This may lead to abnormal blood flow within the heart.
- Heart failure. This condition, in which the heart muscle has become too weak to pump blood well, causes fluid buildup (congestion) in the blood vessels and lungs, and edema (swelling) in the feet, ankles, and other parts of the body.
- Heart valve disease. Malfunction of one or more of the heart valves that can affect blood flow within the heart.
You may have a cardiac cath if you have recently had one or more of these symptoms:
- Chest pain (angina)
- Shortness of breath
- Extreme tiredness
If a screening exam, such as an electrocardiogram (ECG) or stress test suggests there may be a heart condition that needs to be explored further, your doctor may order a cardiac cath.
Another reason for a cath procedure is to evaluate blood flow to the heart muscle if chest pain occurs after the following:
- Heart attack
- Coronary artery bypass surgery
- Coronary angioplasty (the opening of a coronary artery using a balloon or other method) or placement of a stent (a tiny metal coil or tube placed inside an artery to keep the artery open)
There may be other reasons for your doctor to recommend a cardiac cath.
What are the risks of cardiac catheterization?
Possible risks associated with cardiac cath include:
- Bleeding or bruising where the catheter is put into the body (the groin, arm, neck, or wrist)
- Pain where the catheter is put into the body
- Blood clot or damage to the blood vessel that the catheter is put into
- Infection where the catheter is put into the body
- Problems with heart rhythm (usually temporary)
More serious, but rare complications include:
- Ischemia (decreased blood flow to the heart tissue), chest pain, or heart attack
- Sudden blockage of a coronary artery
- A tear in the lining of an artery
- Kidney damage from the dye used
If you are pregnant or think you could be, tell your doctor due to risk of injury to the fetus from a cardiac cath. Radiation exposure during pregnancy may lead to birth defects. Also be sure to tell your doctor if you are lactating, or breastfeeding.
There is a risk for allergic reaction to the dye used during the cardiac cath. If you are allergic to or sensitive to medicines, contrast dye, iodine, or latex, tell your doctor. Also, tell your doctor if you have kidney failure or other kidney problems.
For some people, having to lie still on the cardiac cath table for the length of the procedure may cause some discomfort or pain.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor before the procedure.
What happens after cardiac catheterization?
In the hospital
After the cardiac cath, you may be taken to a recovery room or returned to your hospital room. You will stay flat in bed for several hours. A nurse will monitor your vital signs, the insertion site, and circulation/sensation in the affected leg or arm.
Let your nurse know right away if you feel any chest pain or tightness, or any other pain, as well as any feelings of warmth, bleeding, or pain at the insertion site.
Bedrest may vary from 4 to 12 hours. If your doctor placed a closure device, your bedrest may be shorter.
In some cases, the sheath or introducer may be left in the insertion site. If so, you will be on bedrest until your doctor removes the sheath. After the sheath is removed, you may be given a light meal.
You may feel the urge to urinate often because of the effects of the contrast dye and increased fluids. You will need to use a bedpan or urinal while on bedrest so you don't bend the affected leg or arm.
After the period of bed rest, you may get out of bed. The nurse will help you the first time you get up, and may check your blood pressure while you are lying in bed, sitting, and standing. You should move slowly when getting up from the bed to avoid any dizziness from the long period of bedrest.
You may be given pain medicine for pain or discomfort related to the insertion site or having to lie flat and still for a prolonged period.
Drink plenty of water and other fluids to help flush the contrast dye from your body.
You may go back to your usual diet after the procedure, unless your doctor tells you otherwise.
After the recovery period, you may be discharged home unless your doctor decides otherwise. In many cases, you may spend the night in the hospital for careful observation. If the cardiac cath was done on an outpatient basis and a sedative was used, you must have another person drive you home.
Once at home, you should check the insertion site for bleeding, unusual pain, swelling, and abnormal discoloration or temperature change. A small bruise is normal. If you notice a constant or large amount of blood at the site that cannot be contained with a small dressing, contact your doctor.
If your doctor used a closure device at your insertion site, you will be given instructions on how to take care of the site. There may be a small knot, or lump, under the skin at the site. This is normal. The knot should go away over a few weeks.
It will be important to keep the insertion site clean and dry. Your doctor will give you specific bathing instructions.
Your doctor may advise you not to participate in any strenuous activities for a few days after the procedure. He or she will tell you when it's OK to return to work and resume normal activities.
Contact your doctor if you have any of the following:
- Fever or chills
- Increased pain, redness, swelling, or bleeding or other drainage from the insertion site
- Coolness, numbness or tingling, or other changes in the affected arm or leg
- Chest pain or pressure, nausea or vomiting, profuse sweating, dizziness, or fainting
Your doctor may give you other instructions after the procedure, depending on your particular situation.