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Medically reviewed by Last updated on Mar 14, 2023.

What is Endocarditis?

Harvard Health Publishing

Endocarditis, also called infective endocarditis, is an infection and inflammation of the heart valves and the inner lining of the heart chambers, which is called the endocardium. Endocarditis occurs when infectious organisms, such as bacteria or fungi, enter the bloodstream and settle in the heart. In most cases, these organisms are streptococci (andquot;strep"), staphylococci (andquot;staph") or species of bacteria that normally live on body surfaces.

The infecting organism enters the bloodstream through a break in the skin caused by a skin disorder or injury; a medical or dental procedure; or a skin prick, especially among intravenous drug users.

Depending on the aggressiveness (virulence) of the infecting germ, the heart damage caused by endocarditis can be swift and severe (acute endocarditis) or slower and less dramatic (subacute endocarditis).

Men develop endocarditis more often than women, and the illness is more common among people who have one or more of the following risk factors:

In about 20% to 40% of patients who do not have artificial heart valves and who do not use intravenous drugs, no heart problem can be identified that would increase their risk of endocarditis. In the 10% to 20% of endocarditis patients who have artificial heart valves, infections that follow within 60 days of valve surgery often are caused by a staphylococcus, while endocarditis that occurs later most frequently is caused by a streptococcus.


Symptoms of acute endocarditis include:

Symptoms of subacute endocarditis include:


Your doctor will review your medical history with particular attention to possible risk factors for endocarditis, including congenital heart disease, rheumatic fever, an artificial heart valve or pacemaker, a history of IV drug use, and a history of chronic illness. Your doctor also will ask whether you have ever been told that you have a heart murmur and whether you have had any recent medical or dental procedure in which bacteria might have had an opportunity to entire your bloodstream (dental scaling, periodontal surgery, professional teeth cleaning, bronchoscopy, certain diagnostic tests of the genitourinary tract, colonoscopy).

Your doctor will examine you, and will check for fever; skin symptoms of endocarditis (tiny hemorrhages in the skin, tender nodules on finger and toes); and a heart murmur, which indicates possible heart valve damage. Additional testing includes:

Expected duration

Symptoms of acute endocarditis usually begin suddenly and get worse quickly. It is an infection that can develop dramatically over a few days. Subacute endocarditis develops more slowly, and its milder symptoms can be present for weeks or months before the illness is suspected.


If you are at high risk of endocarditis because of a damaged heart valve or other medical problem, tell your doctor and dentist. To prevent endocarditis, your doctor and dentist may prescribe antibiotics before you have any medical or dental procedure in which bacteria have a chance of entering your blood. This is called prophylactic antibiotics.

Prophylactic antibiotics usually are given to people with artificial valves, people who had endocarditis in the past and people with other high-risk conditions. Most people with mitral valve prolapse and other minor abnormalities of heart structure do not need antibiotics before medical or dental procedures.

In general, antibiotics are given one to two hours before a high-risk procedure, and up to eight hours afterward. Before a dental procedure, an antiseptic mouth rinse also can be used, especially one containing chlorhexidine or povidone-iodine.

You also can help to prevent endocarditis by avoiding IV drug use.


When endocarditis is caused by a bacterial infection, it usually is treated with four to six weeks of antibiotics. The type of antibiotic and the length of therapy depend on the results of the blood cultures. Antibiotic treatment is given intravenously (through a vein). Treatment is almost always started while you are in the hospital. When your doctor determines it is safe, you can be discharged home to finish the course of intravenous antibiotics.

Sometimes the infected heart valve must be replaced surgically. Indications for surgery may include:

Treatment options

The following list of medications are related to or used in the treatment of this condition.

View more treatment options

When to call a professional

Call your doctor whenever you experience symptoms of acute or subacute endocarditis, especially if you have a history of heart valve damage, a known heart murmur or an implanted device in your heart (artificial valve or pacemaker wire).


With prompt diagnosis and proper medical treatment, over 90% of patients with bacterial endocarditis recover. Those whose endocarditis affects the right side of the heart tend to have a better outlook than those with left-side involvement. In cases in which endocarditis is caused by fungi, the prognosis is usually worse than for bacterial endocarditis.

Some possible complications of endocarditis include:

If endocarditis remains untreated, it can cause severe permanent disability and death.

Additional info

American Heart Association (AHA)

National Heart, Lung, and Blood Institute (NHLBI)

American College of Cardiology

Learn more about Endocarditis

Treatment options

Care guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.