Infective Endocarditis

Infective endocarditis occurs when bacteria settle in the lining of your heart valves. This condition is difficult to detect and treat. Over time, the bacteria form colonies that raise your risk of complications, some of which are life-threatening.


What is infective endocarditis?

Infective endocarditis occurs when your heart lining (endocardium) or heart valves become infected. Heart valves are typically resistant to fungi and bacteria, which is why this condition rarely occurs.


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How does infective endocarditis happen?

Endocarditis starts when fungi or bacteria enter your bloodstream. Streptococcus and staphylococcus bacteria cause approximately four out of five cases.

Infective endocarditis can happen when brushing your teeth or as a complication of open-heart surgery. Bacteria travel through your bloodstream and attach to damaged tissue in your endocardium, forming colonies (vegetations). These colonies release toxins and enzymes that destroy healthy cells and prevent healing.

What are infective endocarditis risk factors?

Infective endocarditis is more likely to occur in people with structural heart disease, including:

These conditions affect heart valve function, leading to:

Additional risk factors include being:

  • Male: Infective endocarditis is twice as common in people assigned male at birth than people assigned female at birth.
  • An older adult: The average age at onset is greater than 50 years.

What are infective endocarditis complications?

When not detected early, bacteria grow and spread, leading to complications such as heart failure.

You may also experience emboli when initial treatments aren't successful. These small clots of bacterial colonies can travel through your bloodstream. If they block a blood vessel, emboli can cause additional, sometimes life-threatening complications because they block the blood supply to vital organs.

These include:

Symptoms and Causes

What are infective endocarditis causes?

Heart conditions and treatments that introduce bacteria into your bloodstream are the primary cause of infective endocarditis. These include:


Are there additional infective endocarditis causes?

On rare occasions, the condition happens in people with healthy hearts. Causes include:

  • A catheter that stays in your blood vessels for a long time. This includes a chronic indwelling catheter for delivering chemotherapy.
  • Conditions affecting your immune system, including HIV and AIDS.
  • An infection elsewhere in your body.
  • Injecting intravenous street drugs with dirty needles.
  • Poor oral hygiene, which causes bacteria to build up in your mouth.
  • Receiving intravenous drugs for a medical condition with a contaminated needle.

What are infective endocarditis symptoms?

Infective endocarditis symptoms often affect your heart and respiratory system. You may experience:

Additional symptoms may include:

Diagnosis and Tests

How is infective endocarditis diagnosed?

Assessments start by considering your symptoms and medical history. A history of heart valve disease and fever of unknown origin are two primary concerns. Other combinations of infective endocarditis symptoms may raise suspicions as well. The only way to know for sure is by testing.

What type of diagnostic testing might I need?

A bacteria culture test helps detect the presence of bacteria in your blood. Additional testing is often necessary to plan treatments.

These include:

Management and Treatment

What type of treatment might I need?

Initial infective endocarditis treatment consists of broad-spectrum antibiotics. They may relieve symptoms but might not be effective enough to help your body get rid of the infection for good.

When your antibody serology test results are available, healthcare providers switch you to an antibiotic targeting the specific bacteria in your blood. You may need to be on intravenous (IV) antibiotic treatment for four to six weeks.

Will I need surgery?

When vegetations are small, antibiotics might be the only treatment you need. Large vegetations may require infective endocarditis surgery to remove them and replace the damaged valves.

Surgery may also be necessary for vegetations invading nearby tissue. In severe cases, it might be best to perform surgery before starting antibiotics. Researchers are still working to confirm when surgery before antibiotics is appropriate.


How can I avoid infective endocarditis?

Prevention used to involve daily antibiotics for people at risk for infective endocarditis. However, this practice can increase antibiotic resistance.

Now, healthcare providers prescribe a short course of antibiotics before specific procedures. These include dental treatments when incisions are necessary. Preventive (prophylactic) antibiotics are used only for people facing the highest risk of infective endocarditis, such as those with artificial heart valves.

Outlook / Prognosis

What is the prognosis for infective endocarditis?

Without early, aggressive antibiotic therapy, the prognosis for this condition is poor. People who receive timely infective endocarditis treatment have the best chances for survival. Complications can slow your recovery.

Living With

How might my life be different with infective endocarditis?

Once you’ve had infective endocarditis, you face a higher risk of getting it again. You can lower this risk by:

  • Brushing and flossing your teeth twice a day.
  • Communicating with your healthcare providers, including your dentist, about your infective endocarditis risk.
  • Getting your teeth cleaned every six months.
  • If you have heart valve disease, following care instructions to prevent symptoms from worsening.

A note from Cleveland Clinic

Infective endocarditis is a bacterial infection that occurs in your heart valve lining. It is a rare condition that’s challenging to treat. But recovery is possible. If you're at risk, it’s essential to minimize bacteria exposure. You can do this by taking excellent care of your teeth and gums. If you need a procedure, communicate with your healthcare provider about ways to keep you safe.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/17/2022.

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