Endocarditis is an infection of the heart’s valves or inner lining of the heart. It is most often caused by bacteria. It also can be caused by fungi. The bacteria or fungi get into the bloodstream. They settle and grow on the inside of the heart, usually on the heart valves. Bacteria or fungi can enter the bloodstream in many ways, such as through some dental and medical procedures.

This infection can damage your heart. You need to treat it as soon as possible.

People who have a normal heart are not likely to get endocarditis. But some people are more likely to get it than others. This includes people who have a heart problem that affects normal blood flow, such as a heart valve problem, or people who inject illegal drugs.

Endocarditis can be very serious. It may be more dangerous for people who:

  • Have an artificial heart valve.
  • Have had this kind of infection before.
  • Have had certain heart problems since birth.
  • Have heart valve problems after a heart transplant.


What are the symptoms of endocarditis?

Symptoms may appear quickly, within a few days of infection. In other cases, they may develop more slowly. The symptoms will get worse as the bacteria or fungi grow in your heart.

Symptoms may include:

  • Flu-like symptoms such as fever, chills, night sweats, and fatigue. These are often the first symptoms.
  • Weight loss.
  • Muscle or joint pain.
  • Cough.
  • Shortness of breath.
  • Blood under the fingernails or tiny purple and red spots under the skin.

See your doctor if you have symptoms like these that don't go away, especially if you are at risk for endocarditis.

If endocarditis isn't treated soon, it can lead to more serious problems, such as:

  • Heart failure.
  • An abscess in the heart.
  • Heart rhythm problems.
  • Heart attack or stroke.
  • Infections in other organs, such as the lungs, brain, or kidneys.


How can you prevent endocarditis?

  • Practice good oral hygiene by brushing and flossing your teeth daily. See a dentist twice each year. Tell your dentist that you are at risk for this infection.
  • You may need to take antibiotics before some dental and medical procedures if you:
    • Have had a heart valve replaced or repaired.
    • Have had endocarditis before.
    • Have had certain heart problems since birth.
    • Have heart valve problems after a heart transplant.

Ask your doctor or dentist if you need antibiotics to prevent this infection. Find out when you will need to take them.

Your doctor may give you a card that says you may need preventive antibiotics before some procedures. You can keep it in your wallet.

Who should take antibiotics to prevent endocarditis?

If you have certain heart conditions, you may need to take antibiotics before you have some dental or surgical procedures that could put bacteria or fungi into your blood. The antibiotics lower your risk of getting endocarditis.

These heart conditions include:

  • A repaired or replaced heart valve.
  • Endocarditis in the past.
  • Heart defects since birth (congenital heart defects).
  • Heart valve problems after a heart transplant.

Your doctor can tell you whether you need to take antibiotics. Before you have any medical, dental, or surgical procedures, tell all other health professionals who may treat you that you are at risk for endocarditis.

Your doctor can issue you a special card to carry in your wallet if you require preventive antibiotics before certain dental or surgical procedures. Your condition and specific antibiotic requirements are outlined on this card. The card is signed by your doctor.


How is endocarditis diagnosed?

First, your doctor will ask about your medical history and your symptoms. The doctor will also do a physical exam to check for signs of the infection. These signs include a heart murmur, an enlarged spleen, and bleeding under the nails.

Your doctor may also do tests, such as:

  • Blood cultures. These tests look for bacteria in your bloodstream.
  • Echocardiogram. This is done to check your heart for problems such as infected areas or heart valve defects.
  • Electrocardiogram (EKG or ECG). This test checks for heart rhythm problems.
  • A chest X-ray. This is to see if your heart is enlarged or if you have signs of heart failure.
  • An MRI (magnetic resonance imaging) test or a CT scan. These may be done as additional tests to check your heart for problems.

Risk Factors

What increases your risk of endocarditis?

Your risk is higher if you have a problem that affects blood flow through your heart. That's because a blood flow problem makes it more likely that bacteria or fungi will attach to heart tissue. Some other things raise your risk too, because they can let bacteria or fungi enter your bloodstream.

You have a higher risk of endocarditis if you:

  • Have had endocarditis in the past.
  • Have an implanted heart device such as a pacemaker or implantable cardioverter-defibrillator (ICD).
  • Have a hemodialysis access or a central vascular access device.
  • Have abnormal or damaged heart valves.
  • Have had a heart valve replaced or repaired.
  • Have a congenital heart defect.
  • Have injected drugs.

Not all heart problems put you at higher risk for endocarditis. You do not have a higher risk if you have had:

  • Bypass surgery for heart disease.
  • Rheumatic fever without heart valve damage.
  • A heart attack without other complications.
  • Mitral valve prolapse without regurgitation or unusually thickened valve leaflets.
  • A coronary artery stent.


How is endocarditis treated?

Endocarditis is usually treated with antibiotics. You will probably need several weeks of treatment. The antibiotics must be given long enough and at a strong enough dose to destroy all of the bacteria.

At first you will be treated in the hospital. This is so that antibiotics can be given through a vein (I.V.). After your fever is gone and you are stable, you may be able to continue I.V. antibiotics at home. A home health nurse can help you with this.

After you have been treated with I.V. antibiotics, your doctor may want you to take antibiotic pills. If so, take them exactly as prescribed until they are gone. If your symptoms come back, call your doctor right away. You probably will need more antibiotics if testing shows that the bacteria were not completely destroyed.

Some people who have endocarditis need surgery to repair or replace a heart valve or to prevent complications.

You may have follow-up visits for months or years to check the health of your heart.

Copyrighted material adapted with permission from Healthwise, Incorporated. This information does not replace the advice of a doctor.