Infective Endocarditis

What is endocarditis?

Endocarditis (also called infective endocarditis) is an infection of the inner lining of the heart. It most often affects the heart valves but can also involve other parts of the heart’s inner lining, including implanted cardiac devices.

It is usually caused by bacteria entering the bloodstream. Less often, fungi or other microorganisms can cause it.

Endocarditis is uncommon. However, people with certain heart conditions have a greater risk of developing it.

View an illustration of endocarditis.

What are the types of endocarditis?

It may be classified by how quickly it develops or whether it involves a prosthetic heart valve.

• Acute endocarditis develops quickly and can become life-threatening within days.
• Subacute (or chronic) endocarditis develops more slowly, over weeks to months.
• Prosthetic valvular endocarditis happens in people who have had a heart valve replaced with an artificial valve.

How does endocarditis happen?

Endocarditis is not contagious. It happens when pathogens enter the bloodstream and travel to the heart.

These pathogens can enter the bloodstream in many ways, including:

• Poor dental health
• Everyday activities, such as brushing or flossing, that may briefly allow bacteria from the mouth to enter the bloodstream
• Dental procedures
• Recently implanted cardiac devices, such as artificial heart valves, pacemakers or implantable defibrillators (Microorganisms can be introduced during implantation or attach to the device if they enter the bloodstream later.)
• Skin conditions or infections, including burns
• Other infections in the body
• IV drug use

Why does endocarditis damage heart valves?

When germs attach to the heart valve, they can multiply and form infected clumps, called vegetations.

Because heart valves have a limited blood supply, it can be difficult for the body’s immune system and some medications to fully clear the infection. Over time, this can damage the valves.

Complications may include fragments of the vegetation breaking loose and traveling through the bloodstream (embolization) or damage to the heart valve.

Who is at risk for endocarditis?

Endocarditis is rare. In most healthy people, microbes that briefly enter the bloodstream are cleared before they can attach to the heart and cause infection.

However, your risk is higher if you have certain heart conditions or other risk factors.

Risk factors in children and young adults

• Certain congenital heart defects, such as abnormal heart valves or structural changes that affect blood flow

Risk factors in adults

• Heart valve disease or damage to the heart valves
• Previous endocarditis
• Prosthetic (artificial) heart valve or material used for valve repair
• Heart transplant with valve disease
• Implanted cardiac devices, such as a pacemaker or implantable cardioverter-defibrillator (ICD)
• Older age, including age-related valve changes (such as calcium buildup)
• Some congenital heart defects
• Poor dental health or gum disease
• Weakened immune system
• History of rheumatic fever (rare in the U.S.)
• IV drug use

IV drug use and endocarditis

People who inject drugs have an increased risk of endocarditis because bacteria and other microorganisms can enter the bloodstream during injection.

When this happens, the tricuspid valve (on the right side of the heart) is most often affected. Less commonly, the infection can also involve the mitral or aortic valves.

What are the symptoms of endocarditis?

Symptoms can vary depending on how quickly the infection develops.

Acute endocarditis often begins suddenly. Signs and symptoms may include:

• Fever and chills
• Fast heart rate
• Fatigue
• Night sweats
• Joint and muscle aches
• Headache
• Cough, difficulty breathing, chest pain

Subacute (chronic) endocarditis develops more gradually. Symptoms may include:

• Fatigue
• Low-grade fever
• Fast heart rate
• Weight loss
• Sweating
• Low red blood cell count (anemia)

How is endocarditis treated?

Treatment usually involves IV antibiotics. The choice of antibiotic and length of treatment depends on the microorganism causing the infection.

In some cases, surgery may be needed, especially if there are complications or the infection does not respond to medications.

Can endocarditis be prevented?

If you are at higher risk, prevention focuses on reducing the chance of infection. This may include:

• Understanding your risk factors
• Maintaining good oral and dental health
• Managing underlying heart conditions and following your healthcare team’s recommendations

Dental procedures and endocarditis

Some people with certain heart conditions are at the highest risk of serious complications from endocarditis. For these people, antibiotics may be recommended before certain dental procedures. This is called antibiotic prophylaxis.

These procedures include those that involve:

• Manipulation of gum tissue
• Work around the roots of the teeth
• Perforation of the lining of the mouth

Who may need antibiotics before dental procedures?

Antibiotics may be recommended for people with the highest risk of serious outcomes from endocarditis, including:

• Prosthetic (artificial) heart valve or material used for valve repair
• Previous endocarditis
• Certain congenital heart diseases (Your cardiologist will tell you if this applies to you.)
• Heart transplant with valve disease

Antibiotics for other medical procedures

For people at highest risk, antibiotics may be reasonable before certain procedures involving infected skin, skin structures, musculoskeletal tissue or, in selected cases, the respiratory tract.

How to reduce your risk

You can help lower your risk of endocarditis by:

• Maintaining good oral health
• Getting regular dental care
• Brushing your teeth (with a manual or powered toothbrush) and flossing regularly

If you need antibiotic prophylaxis

If antibiotics are recommended for you:

• Your healthcare professional may give you an American Heart Association wallet card (PDF) with guidance on antibiotics and dosing.
• Show this card to your dentist and other healthcare professionals.
• Tell your care team about any drug allergies you have.
• For children, antibiotic doses are based on body weight.

Your healthcare team can answer questions and help you understand how to prevent endocarditis.

• Print our patient information sheet What Is Endocarditis? (PDF) | Spanish (PDF)
• Print your own Prevention of Infective Endocarditis Wallet Card (PDF) | Spanish (PDF)